Long-term results of pulmonary valve annular enlargement with valve repair in tetralogy of Fallot

Long-term results of pulmonary valve annular enlargement with valve repair in tetralogy of Fallot Abstract OBJECTIVES We adopted an operative technique of pulmonary valve (PV) annular enlargement with valve repair in tetralogy of Fallot (TOF) correction to reduce postoperative pulmonary regurgitation (PR) 16 years ago. Here, we have evaluated the long-term results. METHODS Between April 2000 and August 2005, 43 patients (26 men) with tetralogy of Fallot with pulmonary stenosis underwent PV annular enlargement with valve repair. The median age and body weight at the time of surgery were 14 months and 10.2 kg, respectively. RESULTS There was no operative mortality. Mean postoperative PR grade at discharge was 0.93 ± 0.40 (none or trivial in 10 patients, mild in 27 patients, mild to moderate in 5 patients and moderate in 1 patient), and the mean postoperative pressure gradient across PV was 13.0 ± 10.9 mmHg. The mean follow-up duration was 131.9 ± 42.9 months. During follow-up, 1 reoperation was performed for residual ventricular septal defect. The mean PR grade at the last follow-up echocardiography was 1.59 ± 0.60 (mild in 17 patients, mild to moderate in 8 patients, moderate in 14 patients, moderate to severe in 1 patient and severe in 3 patients), and the mean pressure gradient was 22.7 ± 9.9 mmHg. We have compared the incidence of moderate or more PR with the incidence of patients who underwent simple transannular patch enlargement through propensity score matching. The PV repair group had a lower incidence of moderate or more PR compared with the simple transannular patch group (40% vs 68%, P = 0.04). CONCLUSIONS PV annular enlargement with valve repair has reasonable long-term results and yields a lower long-term incidence of significant PR compared with the simple transannular patch enlargement technique. Tetralogy of Fallot, Transannular patch enlargement, Pulmonary valve preservation INTRODUCTION Surgical repair of tetralogy of Fallot (TOF) with a small pulmonary valve (PV) annulus requires the destruction of the PV and the annulus, resulting in pulmonary regurgitation (PR). Although PR is well tolerated for a short period of time, prolonged exposure to PR can lead to acute and late functional deterioration of the right ventricle, increasing tricuspid regurgitation, left ventricular dysfunction, ventricular arrhythmia and sudden death [1–3]. On enlargement of the PV annulus using a transannular patch (TAP) or a monocusp ventricular outflow patch (MVOP), the patient’s own valve tissue cannot be used, which will become non-functional or obstructive. To overcome these problems, we have tried to repair the PV while enlarging the PV annulus to reduce postoperative PR [4]. This study assesses the long-term results of PV annular enlargement with valve repair in TOF correction and compares these results with those of a simple TAP technique. MATERIALS AND METHODS Patients This study was approved by the institution’s ethics committee/institutional review board because of the retrospective nature of our study (IRB no. 05-2016-149). A chart review was undertaken to identify all patients undergoing a repair of TOF. Between April 2000 and August 2005, 89 consecutive patients with TOF/pulmonary stenosis underwent a complete repair at Pusan National and Dong-A University Hospitals. Of these 89 patients, PV was preserved in 32 (36%) patients, and PV annular enlargement with valve repair was carried out in 43 (48%) patients. The remaining 14 (16%) patients underwent annular enlargement without PV repair due to a small ventricular incision through the anterior commissure in 6 patients, too small pulmonary cusp to be repaired in 5 patients, valvectomy in 2 patients and abnormal coronary artery crossing the right ventricular outflow tract (RVOT) in 1 patient. As a result, 43 patients (26 men, 61%) who underwent PV annular enlargement with valve repair were enrolled in this study. The median age and body weight at the time of surgery were 14 months (range 6–35 months) and 10.2 kg (range 6–14 kg), respectively. Preoperative Blalock–Taussig shunt was performed in 10 (23%) patients. The mean PV annulus size was 8.8 ± 1.0 mm, and 37 (86%) patients had a bicuspid PV. The types of ventricular septal defect (VSD) were perimembranous in 29 (67%) patients, subarterial in 8 (19%) patients and muscular outlet in 6 (14%) patients. Technique The surgery was performed on the arrested heart using cardioplegic solution under moderate hypothermia. After induction of cardiac arrest, a longitudinal incision was made on the main pulmonary artery (MPA), and the PV was inspected. If the PV was too small to be preserved, the incision was extended to the RVOT crossing the PV annulus. Several PV repair techniques were adopted in the setting of the transannular incision, and these techniques were previously reported by our group [4]. Technical modifications depending on valve morphologies are illustrated in Fig. 1. Figure 1: View largeDownload slide Schematic drawings of pulmonary valve repair techniques. (A) The anterior cusp is divided, and the divided cusps and ventriculotomy site are filled with a patch (n = 15, 35%). (B) A partial incision is made over the anterior cusp, and the defect in the valve and ventriculotomy are filled with a patch (n = 8, 19%). (C) The anterior commissure is divided, and a patch is anchored to both incised main pulmonary artery walls (n = 3, 7%). (D) Either cusp is divided eccentrically, and a patch is sewn to the main pulmonary artery wall and to the free edge of the divided cusp (n = 17, 40%). (E) Technical modifications of the pulmonary valve repair technique. The red arrows show directions of the incision in each technique. PTFE: polytetrafluoroethylene. Figure 1: View largeDownload slide Schematic drawings of pulmonary valve repair techniques. (A) The anterior cusp is divided, and the divided cusps and ventriculotomy site are filled with a patch (n = 15, 35%). (B) A partial incision is made over the anterior cusp, and the defect in the valve and ventriculotomy are filled with a patch (n = 8, 19%). (C) The anterior commissure is divided, and a patch is anchored to both incised main pulmonary artery walls (n = 3, 7%). (D) Either cusp is divided eccentrically, and a patch is sewn to the main pulmonary artery wall and to the free edge of the divided cusp (n = 17, 40%). (E) Technical modifications of the pulmonary valve repair technique. The red arrows show directions of the incision in each technique. PTFE: polytetrafluoroethylene. If there was significant commissural fusion or tethering of the cusps to the pulmonary artery wall, these were sharply divided. We released the tethering of the posterior cusp to improve its excursion. Tethering of the anterior cusp was left untouched to preserve the native PV commissural hinge function. The anterior cusp was then divided, and the divided cusps and the ventriculotomy site were filled with a glutaraldehyde-treated autologous pericardial patch. Our target annulus size in the arrested heart was 2 mm larger than the mean normal-sized pulmonary annulus [5]. The incision at the MPA was covered with a second patch, which was placed on the previous pericardial patch used in the valve repair in the ventricular side (Fig. 1A, n = 15, 35%). Alternative techniques of annular enlargement were also used. Partial incision was made at the anterior cusp, and the defect of the valve and ventriculotomy were filled with the patch (Fig. 1B, n = 8, 19%). We applied this technique to a small number of patients during the early experience. When the patient had right and left cusps, the anterior commissure was divided, and the patch was anchored to both incised MPA walls (Fig. 1C, n = 3, 7%). In patients in whom the commissure was eccentric, either cusp was divided eccentrically. The patch was sewn to the MPA wall and to the free edge of the divided cusp (Fig. 1D, n = 17, 40%). Since June 2003, 2 important modifications have been made to our technique for improving the durability of the repaired valve. First, a 0.1-mm polytetrafluoroethylene (PTFE) membrane (GoreTex; W.L. Gore & Associates, Inc. Newark, NJ, USA) was used as patch material. Second, our target annulus size was reduced to make the ventriculotomy smaller, which was 1 mm larger than the normal PV annulus size in the arrested heart (Fig. 1E). When the PTFE membrane used in valve repair was placed to the ventriculotomy incision, the suture was placed at the endocardial side of the incised myocardium as much as possible. The outer patch for the MPA incision was placed to the epicardial side of the incised RVOT wall. This technique was used in the last 12 patients. The mean duration of cardiopulmonary bypass was 163.0 ± 30.1 min, and the mean duration of aortic cross-clamp was 104.8 ± 17.0 min. The mean RVOT ventriculotomy size was 12.6 ± 3.6 mm, and VSD was closed through the right atrium in 26 (61%) patients, the ventriculotomy site in 13 (30%) patients and both the right atrium and the ventriculotomy site in 4 (9%) patients. The patch materials used in the PV repair were a glutaraldehyde-treated autologous pericardium in 31 (72%) patients and a 0.1-mm PTFE membrane in 12 (28%) patients. The mean RV to systemic pressure ratio after cardiopulmonary bypass weaning was 0.48 ± 0.10 (range 0.27–0.75). Procedures on the branch pulmonary arteries were required in 11 (26%) patients. All postoperative echocardiographic reports were reviewed, and PR was graded as follows: 0 = none, 0.5 = trivial, 1 = mild, 1.5 = mild to moderate, 2 = moderate, 2.5 = moderate to severe and 3 = severe [6]. Statistical analysis Data were collected and managed using Microsoft Excel 2013 and analysed using SPSS 21.0 (SPSS, Inc., Chicago, IL, USA). Categorical variables were compared using the χ2 test and continuous variables using the Student’s t-test. The Kaplan–Meier survival curve analysis was used to analyse freedom from pulmonary valve replacement (PVR), and survival curves were compared using the log-rank test. For comparison with the simple TAP technique, propensity score matching was used to overcome group baseline differences. The propensity score matching method was performed to approximate a random assignment for the PV repair group and the simple TAP group by adjusting their age and body weight at surgery, PV annulus size and echocardiography follow-up duration, which could influence on the results of the surgery. More specifically, the nearest neighbour-matching method was used to optimize the matching results, and also to even the size of each group, the ratio was fixed to 1:1. We found that the matched groups showed no significant differences for the adjusted factors [7]. A P-value of <0.05 was considered statistically significant. RESULTS Early results There was no operative mortality. The mean postoperative mechanical ventilation time was 28.1 ± 19.3 h (range 10–109 h), and most of the patients (39 of 43 patients, 91%) were extubated within 48 h. The mean hospital stay was 9.9 ± 4.1 days (range 6–31 days). The mean postoperative PR grade at discharge was 0.93 ± 0.40 [none or trivial in 10 patients (23%), mild in 27 patients (63%), mild to moderate in 5 patients (12%) and moderate in 1 patient (2%)], and the mean postoperative pressure gradient (PG) across the PV was 13.0 ± 10.9 mmHg (range 5–43 mmHg). Of the 43 patients, only 1 (2%) patient had moderate PR at discharge. Late results The mean follow-up duration was 131.9 ± 42.9 months (range 29–198 months). During follow-up, 1 reoperation was performed for a residual VSD. Eight reinterventions were performed in 6 (14%) patients, and all reinterventions were balloon angioplasties for left pulmonary artery stenosis. There were 3 late deaths, but all late deaths were not related to cardiac origin. The causes of death were Fanconi anaemia, haemophagocytic syndrome and upper airway problem. The mean echocardiography follow-up duration was 123.7 ± 43.2 months (range 29–198 months). The mean PR grade at the last follow-up echocardiography was 1.59 ± 0.60 [mild in 17 patients (40%), mild to moderate in 8 patients (19%), moderate in 14 patients (33%), moderate to severe in 1 patient (2%) and severe in 3 patients (7%)], and the mean PG across the PV was 22.7 ± 9.9 mmHg (range 10–49 mmHg). Eighteen (42%) patients had moderate or more PR grade at the last follow-up echocardiography. PR grade (Fig. 2, P < 0.01) and PG across the PV (Fig. 3, P < 0.01) tended to increase with time. Risk factors for moderate or more PR grade at the last follow-up echocardiography were analysed, but we could not identify any risk factor for significant PR grade, except cardiopulmonary bypass time (Table 1). Table 1: Risk factor analysis for moderate or more PR at the last follow-up echocardiography Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 ACC: aortic cross-clamp; BT: Blalock–Taussig; CPB: cardiopulmonary bypass; MO: muscular outlet; PM: perimembranous; PR: pulmonary regurgitation; PTFE: polytetrafluoroethylene; PV: pulmonary valve; RA: right atrium; RV: right ventricle; SA: subarterial; SD: standard deviation; VSD: ventricular septal defect. Table 1: Risk factor analysis for moderate or more PR at the last follow-up echocardiography Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 ACC: aortic cross-clamp; BT: Blalock–Taussig; CPB: cardiopulmonary bypass; MO: muscular outlet; PM: perimembranous; PR: pulmonary regurgitation; PTFE: polytetrafluoroethylene; PV: pulmonary valve; RA: right atrium; RV: right ventricle; SA: subarterial; SD: standard deviation; VSD: ventricular septal defect. Figure 2: View largeDownload slide Postoperative pulmonary regurgitation (PR) changes. Figure 2: View largeDownload slide Postoperative pulmonary regurgitation (PR) changes. Figure 3: View largeDownload slide Postoperative pressure gradient (PR) change through the pulmonary valve. Figure 3: View largeDownload slide Postoperative pressure gradient (PR) change through the pulmonary valve. Comparison with the simple transannular patch technique We have compared the present 43 patients with 63 patients who underwent transannular enlargement with a simple TAP technique between September 1996 and April 2011. The mean age and body weight at the time of surgery were 9.6 ± 5.1 months and 8.0 ± 2.0 kg, respectively. The mean follow-up duration was 88.0 ± 51.4 months. The 63 patients were divided into 2 subgroups: large ventriculotomy (>5 mm, n = 32, 51%) and limited ventriculotomy (≤5 mm, n = 31, 49%). On comparing with the large ventriculotomy group, the patients undergoing PV repair had lower PR grade at both immediate postoperative (P < 0.01) and the last follow-up (P = 0.02) echocardiography. On comparing with the limited ventriculotomy group, the patients undergoing PV repair had lower PR grade only at immediate postoperative echocardiography (P < 0.01). There was no significant difference between the 2 groups (P = 0.48) at the last follow-up echocardiography (Table 2). Figure 4 shows the mean postoperative PR grade changes in terms of the PV annulus enlargement technique: PV repair, large ventriculotomy and limited ventriculotomy. Of the 63 patients, 3 (5%) patients underwent PVR in the entire simple TAP group, whereas none of the patients required PVR in the PV repair group (Fig. 5, P = 0.11, log-rank test). Table 2: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique depending on the ventriculotomy size PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c The values in parentheses for the “Last PR grade (moderate or more PR)” indicate the number of patients who have moderate or more PR grade at the last F/U echocardiography. a Reoperation due to residual VSD closure. b Reoperation due to PVR in 2 patients and pacemaker insertion in 1 patient. c Reoperation due to PVR in 1 patient and aortopexy in 1 patient. * P < 0.05: PV repair versus large ventriculotomy (>5 mm). ** P < 0.05: PV repair versus limited ventriculotomy (≤5 mm). ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; PVR: pulmonary valve replacement; SD: standard deviation; TAP: transannular patch; VSD: ventricular septal defect. Table 2: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique depending on the ventriculotomy size PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c The values in parentheses for the “Last PR grade (moderate or more PR)” indicate the number of patients who have moderate or more PR grade at the last F/U echocardiography. a Reoperation due to residual VSD closure. b Reoperation due to PVR in 2 patients and pacemaker insertion in 1 patient. c Reoperation due to PVR in 1 patient and aortopexy in 1 patient. * P < 0.05: PV repair versus large ventriculotomy (>5 mm). ** P < 0.05: PV repair versus limited ventriculotomy (≤5 mm). ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; PVR: pulmonary valve replacement; SD: standard deviation; TAP: transannular patch; VSD: ventricular septal defect. Figure 4: View largeDownload slide Postoperative pulmonary regurgitation change depending on each technique. F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Figure 4: View largeDownload slide Postoperative pulmonary regurgitation change depending on each technique. F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Figure 5: View largeDownload slide Freedom from pulmonary valve replacement (PVR). F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Figure 5: View largeDownload slide Freedom from pulmonary valve replacement (PVR). F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Using propensity score matching, 25 patients who underwent PV repair and 25 patients who underwent the simple TAP technique were selected. Baseline balance was assessed by standardized differences. Each group was well balanced with respect to age and body weight at surgery, PV annulus size and echocardiography follow-up duration (Table 3). The PV repair group had a lower incidence of moderate or more PR grade at the last follow-up echocardiography compared with the simple TAP group (40% vs 68%, P = 0.04). Table 3: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique using propensity score matching PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 a Matching elements. ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; SD: standard deviation; TAP: transannular patch. Table 3: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique using propensity score matching PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 a Matching elements. ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; SD: standard deviation; TAP: transannular patch. DISCUSSION The incidence of TAP enlargement in the repair of TOF has decreased after the introduction of several PV preservation strategies [6, 8–12]. However, a certain proportion of patients with a small PV annulus have required TAP enlargement. The TAP enlargement inevitably produces postoperative PR, which can adversely affect the long-term results of TOF correction [13, 14]. TAP with MVOP has been the main surgical technique to reduce postoperative PR. However, valve function of the MVOP does not persist for a long time [15–19]. In our opinion, the valve function of our PV repair technique lasts longer than the valve function of the MVOP technique because the repaired valve can retain partial or complete native hinge function, even though the mechanism of limited longevity of the MVOP remains unclear. The main purpose of our repair policy of the PV is to preserve the native hinge function of the PV as well as to preserve the native PV tissues as much as possible. We think that the patch attached to the native valve cusp that has the hinge function can hardly adhere to the outer RVOT patch unlike in the MVOP in which the valve cusp without the native valve hinge function can adhere to the outer patch easily. In addition to preserving the native PV hinge function, the valve repair technique has an important advantage over the MVOP in terms of technical flexibility. In contrast to MVOP, it allows the technique to be used even when only a small enlargement of the PV annulus is needed. The MVOP procedure usually requires a relatively large RVOT incision, which is a potential source of a late problem when the valve function of the MVOP disappears. However, after the valve repair, we expect the growth of the remaining repaired native valve tissue that is functioning. We postulate that functioning PV tissues would grow more than non-functioning valve tissues. During the early postoperative period, only 1 (2%) patient had moderate PR, and the PG across the PV was not significant (13.0 ± 10.9 mmHg). Although PR tended to increase over the long-term follow-up (Fig. 2), approximately 40% of the patients retained mild PR long after the surgery, which was believed to be an important contribution of the PV repair technique. There was also a tendency of increasing PG across the PV, but the mean PG across the PV was not significant (22.7 ± 9.9 mmHg) over the ensuing 123.7 ± 43.2 months of echocardiography follow-up (Fig. 3). We compared the outcomes of these patients with those of the 63 patients who had undergone the simple TAP technique. The patients were divided into limited and large ventriculotomy subgroups in terms of the ventriculotomy size. The patients who underwent PV repair had lower PR grade at the immediate postoperative period when compared with both subgroups. However, at the last follow-up, the PV repair group had lower PR grade when compared with the large ventriculotomy group but not when compared with the limited ventriculotomy group (Table 2). The identical degree of PR between the PV repair and the limited TAP groups indicates that both techniques can reduce PR when compared with TAP enlargement with a large incision. The mechanism to reduce PR in both techniques seems to be quite different, and we also need to be aware of the difference in follow-up duration between these 2 techniques (Fig. 4). Propensity score matching was used to compare postoperative PR between the PV repair and the simple TAP technique. Lower immediate postoperative PR grade and lower incidence of moderate or more PR grade at the last follow-up echocardiography were evident in the patients who underwent the PV repair technique. Although a statistically significant difference was not observed, none of the patients needed PVR in the PV repair group, while 3 (5%) patients required PVR in the simple TAP group. Most of the patients had a good PV motion on early postoperative echocardiography at discharge, which was consistent with a previous study [4]. However, in some patients, the valve motion was decreased or absent at the follow-up echocardiography, and shrinkage and thickening of the reconstructed PV cusp were evident. This prompted us to change the patch material from glutaraldehyde-treated autologous pericardium to a 0.1-mm PTFE membrane and to reduce the target annulus size to minimize the ventriculotomy size. There was no statistically significant difference in the incidence of moderate or more PR grade at the last follow-up echocardiography in terms of the 2 patch materials. However, more patients who underwent PV repair using the glutaraldehyde-treated autologous pericardial patch had moderate or more PR grade at the last follow-up echocardiography [15/31 (48%) vs 3/12 (25%); P = 0.16]. An important limitation of the PV repair technique is that it is somewhat difficult to apply to a small baby with a small PV or friable valve tissue. Thus, the technique has not been used frequently in our hospital because our policy for TOF correction was changed to early repair with maximization of PV and RVOT preservation, in which nearly all patients with TOF are repaired between 3 months and 6 months of age. Instead, we have usually performed a small transannular ventriculotomy when TAP enlargement is required. However, we have currently started the PV repair technique even in a small infant patient who requires a small transannular ventriculotomy as inspired by the favourable long-term results of the PV repair. The target PV annulus size in our current practice is just the normal size or 1 mm below the normal size in the arrested heart to minimize the ventriculotomy. The strategy that has also been established is that as the age at TOF repair becomes younger, the PV annulus can be preserved in approximately 70% of all patients with TOF [20]. However, we have been concentrating on the preservation of the PV annulus and RVOT muscle rather than the preservation of the valve tissue itself. In fact, it is very difficult to preserve the valve function completely in small bicuspid PV. We believe that the amount of valve function that can be preserved mainly depends on the native valve morphology. In a patient with small PV annulus having anterior and posterior commissures, we usually perform commissurotomy and small ventriculotomy through the anterior commissure. However, if the patients have the right and left commissures with sizeable and good anterior valve cusp, we place a fresh autologous pericardial patch between the divided anterior cusps, regardless of the ventriculotomy size in a small baby. A fresh autologous pericardial patch is used because of technical considerations. It is technically demanding to use a 0.1-mm PTFE membrane for repair of the small valve cusp in a small baby with TOF. We use a 0.1-mm PTFE membrane for repair of the PV in large-sized or old patients with TOF who require a long right ventricular incision. We believe that the same favourable long-term result can be expected in a young infant in spite of the fact that the PV repair is technically more demanding. Karl and colleagues [21] reported early results of PV repair in 2007. The patients in their study were much younger than our series. Although the tissue or the material used in valve repair can be thickened or shrunk, the repaired remaining native PV tissue still has growth potential, which could reduce PR to some extent. However, in reality, it is sometimes technically demanding to repair small valve cusps and even more demanding in dysplastic small valve cusps. Our study demonstrates that patients who require TAP enlargement could benefit from the valve repair technique in terms of reduction of the PR in the long term and that the feasibility of the valve repair technique in a small baby is dependent on the surgeon’s hand. Limitations The limitations of this study include a relatively small number of patients and the lack of a proper comparative group of patients. Because this was neither a prospective nor a case–control study, the patients were not matched for demographic data. To overcome this limitation, we used the propensity score matching method. CONCLUSION In conclusion, PV annular enlargement with valve repair technique in TOF correction provides excellent valve function in the early postoperative period and also reduces late postoperative PR. Funding This work was supported by a 2-year research grant from the Pusan National University. Conflict of interest: none declared. REFERENCES 1 Ellison RG , Brown WJ Jr , Yeh TJ , Hamilton WF. Surgical significance of acute and chronic pulmonary valvular insufficiency . J Thorac Cardiovasc Surg 1970 ; 60 : 549 – 58 . Google Scholar PubMed 2 Geva T , Sandweiss BM , Gauvreau K , Lock JE , Powell AJ. Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging . J Am Coll Cardiol 2004 ; 43 : 1068 – 74 . Google Scholar CrossRef Search ADS PubMed 3 Helbing WA , Niezen RA , Le Cessie S , van der Geest RJ , Ottenkamp J , de Roos A. Right ventricular diastolic function in children with pulmonary regurgitation after repair of tetralogy of Fallot: volumetric evaluation by magnetic resonance velocity mapping . J Am Coll Cardiol 1996 ; 28 : 1827 – 35 . Google Scholar CrossRef Search ADS PubMed 4 Sung SC , Kim S , Woo JS , Lee YS. Pulmonic valve annular enlargement with valve repair in tetralogy of Fallot . Ann Thorac Surg 2003 ; 75 : 303 – 5 . Google Scholar CrossRef Search ADS PubMed 5 Kouchoukos NT , Blackstone EH , Hanley FL , Kirklin JK. Kirklin/Barratt-Boyes Cardiac Surgery . 4th edn . Philadelphia, PA : Saunders , 2013 , 34 . 6 Ito H , Ota N , Murata M , Tosaka Y , Ide Y , Tachi M et al. Technical modification enabling pulmonary valve-sparing repair of a severely hypoplastic pulmonary annulus in patients with tetralogy of Fallot . Interact CardioVasc Thorac Surg 2013 ; 16 : 802 – 7 . Google Scholar CrossRef Search ADS PubMed 7 Ho DE , Imai K , King C , Stuart EA. Matching as nonparametric preprocessing for reducing model dependence in parametric causal Inference . Polit Anal 2007 ; 15 : 199 – 236 . Google Scholar CrossRef Search ADS 8 Bacha E. Valve-sparing options in tetralogy of Fallot surgery . Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2012 ; 15 : 24 – 6 . Google Scholar CrossRef Search ADS PubMed 9 Kawashima Y , Kitamura S , Nakano S , Yagihara T. Corrective surgery for tetralogy of Fallot without or with minimal right ventriculotomy and with repair of the pulmonary valve . Circulation 1981 ; 64 : II147 – 53 . Google Scholar PubMed 10 Mavroudis CD , Frost J , Mavroudis C. Pulmonary valve preservation and restoration strategies for repair of tetralogy of Fallot . Cardiol Young 2014 ; 24 : 1088 – 94 . Google Scholar CrossRef Search ADS PubMed 11 Bacha E. Valve-sparing or valve reconstruction options in tetralogy of Fallot surgery . Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2017 ; 20 : 79 – 83 . Google Scholar CrossRef Search ADS PubMed 12 Vida VL , Guariento A , Zucchetta F , Padalino M , Castaldi B , Milanesi O et al. Preservation of the pulmonary valve during early repair of tetralogy of Fallot: surgical techniques . Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2016 ; 19 : 75 – 81 . Google Scholar CrossRef Search ADS PubMed 13 Carvalho JS , Shinebourne EA , Busst C , Rigby ML , Redington AN. Exercise capacity after complete repair of tetralogy of Fallot: deleterious effects of residual pulmonary regurgitation . Br Heart J 1992 ; 67 : 470 – 3 . Google Scholar CrossRef Search ADS PubMed 14 Kirklin JK , Kirklin JW , Blackstone EH , Milano A , Pacifico AD. Effect of transannular patching on outcome after repair of tetralogy of Fallot . Ann Thorac Surg 1989 ; 48 : 783 – 91 . Google Scholar CrossRef Search ADS PubMed 15 Bigras JL , Boutin C , McCrindle BW , Rebeyka IM. Short-term effect of monocuspid valves on pulmonary insufficiency and clinical outcome after surgical repair of tetralogy of Fallot . J Thorac Cardiovasc Surg 1996 ; 112 : 33 – 7 . Google Scholar CrossRef Search ADS PubMed 16 Gundry SR , Razzouk AJ , Boskind JF , Bansal R , Bailey LL. Fate of the pericardial monocusp pulmonary valve for right ventricular outflow tract reconstruction. Early function, late failure without obstruction . J Thorac Cardiovasc Surg 1994 ; 107 : 908 – 12 ; discussion 12–3. Google Scholar PubMed 17 Kim H , Sung SC , Kim SH , Chang YH , Lee HD , Park JA et al. Early and late outcomes of total repair of tetralogy of Fallot: risk factors for late right ventricular dilatation . Interact CardioVasc Thorac Surg 2013 ; 17 : 956 – 62 . Google Scholar CrossRef Search ADS PubMed 18 Park CS , Lee JR , Lim HG , Kim WH , Kim YJ. The long-term result of total repair for tetralogy of Fallot . Eur J Cardiothorac Surg 2010 ; 38 : 311 – 7 . Google Scholar CrossRef Search ADS PubMed 19 Jang WS , Cho JY , Lee JU , Lee Y. Surgical results of monocusp implantation with transannular patch angioplasty in tetralogy of Fallot repair . Korean J Thorac Cardiovasc Surg 2016 ; 49 : 344 – 9 . Google Scholar CrossRef Search ADS PubMed 20 Choi KH , Sung SC , Kim H , Lee HD , Ban GH , Kim G et al. A novel predictive value for the transannular patch enlargement in repair of tetralogy of Fallot . Ann Thorac Surg 2016 ; 101 : 703 – 7 . Google Scholar CrossRef Search ADS PubMed 21 Anagnostopoulos P , Azakie A , Natarajan S , Alphonso N , Brook MM , Karl TR. Pulmonary valve cusp augmentation with autologous pericardium may improve early outcome for tetralogy of Fallot . J Thorac Cardiovasc Surg 2007 ; 133 : 640 – 7 . Google Scholar CrossRef Search ADS PubMed © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png European Journal of Cardio-Thoracic Surgery Oxford University Press

Long-term results of pulmonary valve annular enlargement with valve repair in tetralogy of Fallot

Loading next page...
 
/lp/ou_press/long-term-results-of-pulmonary-valve-annular-enlargement-with-valve-93DqdeYQ8e
Publisher
Oxford University Press
Copyright
© The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
ISSN
1010-7940
eISSN
1873-734X
D.O.I.
10.1093/ejcts/ezx497
Publisher site
See Article on Publisher Site

Abstract

Abstract OBJECTIVES We adopted an operative technique of pulmonary valve (PV) annular enlargement with valve repair in tetralogy of Fallot (TOF) correction to reduce postoperative pulmonary regurgitation (PR) 16 years ago. Here, we have evaluated the long-term results. METHODS Between April 2000 and August 2005, 43 patients (26 men) with tetralogy of Fallot with pulmonary stenosis underwent PV annular enlargement with valve repair. The median age and body weight at the time of surgery were 14 months and 10.2 kg, respectively. RESULTS There was no operative mortality. Mean postoperative PR grade at discharge was 0.93 ± 0.40 (none or trivial in 10 patients, mild in 27 patients, mild to moderate in 5 patients and moderate in 1 patient), and the mean postoperative pressure gradient across PV was 13.0 ± 10.9 mmHg. The mean follow-up duration was 131.9 ± 42.9 months. During follow-up, 1 reoperation was performed for residual ventricular septal defect. The mean PR grade at the last follow-up echocardiography was 1.59 ± 0.60 (mild in 17 patients, mild to moderate in 8 patients, moderate in 14 patients, moderate to severe in 1 patient and severe in 3 patients), and the mean pressure gradient was 22.7 ± 9.9 mmHg. We have compared the incidence of moderate or more PR with the incidence of patients who underwent simple transannular patch enlargement through propensity score matching. The PV repair group had a lower incidence of moderate or more PR compared with the simple transannular patch group (40% vs 68%, P = 0.04). CONCLUSIONS PV annular enlargement with valve repair has reasonable long-term results and yields a lower long-term incidence of significant PR compared with the simple transannular patch enlargement technique. Tetralogy of Fallot, Transannular patch enlargement, Pulmonary valve preservation INTRODUCTION Surgical repair of tetralogy of Fallot (TOF) with a small pulmonary valve (PV) annulus requires the destruction of the PV and the annulus, resulting in pulmonary regurgitation (PR). Although PR is well tolerated for a short period of time, prolonged exposure to PR can lead to acute and late functional deterioration of the right ventricle, increasing tricuspid regurgitation, left ventricular dysfunction, ventricular arrhythmia and sudden death [1–3]. On enlargement of the PV annulus using a transannular patch (TAP) or a monocusp ventricular outflow patch (MVOP), the patient’s own valve tissue cannot be used, which will become non-functional or obstructive. To overcome these problems, we have tried to repair the PV while enlarging the PV annulus to reduce postoperative PR [4]. This study assesses the long-term results of PV annular enlargement with valve repair in TOF correction and compares these results with those of a simple TAP technique. MATERIALS AND METHODS Patients This study was approved by the institution’s ethics committee/institutional review board because of the retrospective nature of our study (IRB no. 05-2016-149). A chart review was undertaken to identify all patients undergoing a repair of TOF. Between April 2000 and August 2005, 89 consecutive patients with TOF/pulmonary stenosis underwent a complete repair at Pusan National and Dong-A University Hospitals. Of these 89 patients, PV was preserved in 32 (36%) patients, and PV annular enlargement with valve repair was carried out in 43 (48%) patients. The remaining 14 (16%) patients underwent annular enlargement without PV repair due to a small ventricular incision through the anterior commissure in 6 patients, too small pulmonary cusp to be repaired in 5 patients, valvectomy in 2 patients and abnormal coronary artery crossing the right ventricular outflow tract (RVOT) in 1 patient. As a result, 43 patients (26 men, 61%) who underwent PV annular enlargement with valve repair were enrolled in this study. The median age and body weight at the time of surgery were 14 months (range 6–35 months) and 10.2 kg (range 6–14 kg), respectively. Preoperative Blalock–Taussig shunt was performed in 10 (23%) patients. The mean PV annulus size was 8.8 ± 1.0 mm, and 37 (86%) patients had a bicuspid PV. The types of ventricular septal defect (VSD) were perimembranous in 29 (67%) patients, subarterial in 8 (19%) patients and muscular outlet in 6 (14%) patients. Technique The surgery was performed on the arrested heart using cardioplegic solution under moderate hypothermia. After induction of cardiac arrest, a longitudinal incision was made on the main pulmonary artery (MPA), and the PV was inspected. If the PV was too small to be preserved, the incision was extended to the RVOT crossing the PV annulus. Several PV repair techniques were adopted in the setting of the transannular incision, and these techniques were previously reported by our group [4]. Technical modifications depending on valve morphologies are illustrated in Fig. 1. Figure 1: View largeDownload slide Schematic drawings of pulmonary valve repair techniques. (A) The anterior cusp is divided, and the divided cusps and ventriculotomy site are filled with a patch (n = 15, 35%). (B) A partial incision is made over the anterior cusp, and the defect in the valve and ventriculotomy are filled with a patch (n = 8, 19%). (C) The anterior commissure is divided, and a patch is anchored to both incised main pulmonary artery walls (n = 3, 7%). (D) Either cusp is divided eccentrically, and a patch is sewn to the main pulmonary artery wall and to the free edge of the divided cusp (n = 17, 40%). (E) Technical modifications of the pulmonary valve repair technique. The red arrows show directions of the incision in each technique. PTFE: polytetrafluoroethylene. Figure 1: View largeDownload slide Schematic drawings of pulmonary valve repair techniques. (A) The anterior cusp is divided, and the divided cusps and ventriculotomy site are filled with a patch (n = 15, 35%). (B) A partial incision is made over the anterior cusp, and the defect in the valve and ventriculotomy are filled with a patch (n = 8, 19%). (C) The anterior commissure is divided, and a patch is anchored to both incised main pulmonary artery walls (n = 3, 7%). (D) Either cusp is divided eccentrically, and a patch is sewn to the main pulmonary artery wall and to the free edge of the divided cusp (n = 17, 40%). (E) Technical modifications of the pulmonary valve repair technique. The red arrows show directions of the incision in each technique. PTFE: polytetrafluoroethylene. If there was significant commissural fusion or tethering of the cusps to the pulmonary artery wall, these were sharply divided. We released the tethering of the posterior cusp to improve its excursion. Tethering of the anterior cusp was left untouched to preserve the native PV commissural hinge function. The anterior cusp was then divided, and the divided cusps and the ventriculotomy site were filled with a glutaraldehyde-treated autologous pericardial patch. Our target annulus size in the arrested heart was 2 mm larger than the mean normal-sized pulmonary annulus [5]. The incision at the MPA was covered with a second patch, which was placed on the previous pericardial patch used in the valve repair in the ventricular side (Fig. 1A, n = 15, 35%). Alternative techniques of annular enlargement were also used. Partial incision was made at the anterior cusp, and the defect of the valve and ventriculotomy were filled with the patch (Fig. 1B, n = 8, 19%). We applied this technique to a small number of patients during the early experience. When the patient had right and left cusps, the anterior commissure was divided, and the patch was anchored to both incised MPA walls (Fig. 1C, n = 3, 7%). In patients in whom the commissure was eccentric, either cusp was divided eccentrically. The patch was sewn to the MPA wall and to the free edge of the divided cusp (Fig. 1D, n = 17, 40%). Since June 2003, 2 important modifications have been made to our technique for improving the durability of the repaired valve. First, a 0.1-mm polytetrafluoroethylene (PTFE) membrane (GoreTex; W.L. Gore & Associates, Inc. Newark, NJ, USA) was used as patch material. Second, our target annulus size was reduced to make the ventriculotomy smaller, which was 1 mm larger than the normal PV annulus size in the arrested heart (Fig. 1E). When the PTFE membrane used in valve repair was placed to the ventriculotomy incision, the suture was placed at the endocardial side of the incised myocardium as much as possible. The outer patch for the MPA incision was placed to the epicardial side of the incised RVOT wall. This technique was used in the last 12 patients. The mean duration of cardiopulmonary bypass was 163.0 ± 30.1 min, and the mean duration of aortic cross-clamp was 104.8 ± 17.0 min. The mean RVOT ventriculotomy size was 12.6 ± 3.6 mm, and VSD was closed through the right atrium in 26 (61%) patients, the ventriculotomy site in 13 (30%) patients and both the right atrium and the ventriculotomy site in 4 (9%) patients. The patch materials used in the PV repair were a glutaraldehyde-treated autologous pericardium in 31 (72%) patients and a 0.1-mm PTFE membrane in 12 (28%) patients. The mean RV to systemic pressure ratio after cardiopulmonary bypass weaning was 0.48 ± 0.10 (range 0.27–0.75). Procedures on the branch pulmonary arteries were required in 11 (26%) patients. All postoperative echocardiographic reports were reviewed, and PR was graded as follows: 0 = none, 0.5 = trivial, 1 = mild, 1.5 = mild to moderate, 2 = moderate, 2.5 = moderate to severe and 3 = severe [6]. Statistical analysis Data were collected and managed using Microsoft Excel 2013 and analysed using SPSS 21.0 (SPSS, Inc., Chicago, IL, USA). Categorical variables were compared using the χ2 test and continuous variables using the Student’s t-test. The Kaplan–Meier survival curve analysis was used to analyse freedom from pulmonary valve replacement (PVR), and survival curves were compared using the log-rank test. For comparison with the simple TAP technique, propensity score matching was used to overcome group baseline differences. The propensity score matching method was performed to approximate a random assignment for the PV repair group and the simple TAP group by adjusting their age and body weight at surgery, PV annulus size and echocardiography follow-up duration, which could influence on the results of the surgery. More specifically, the nearest neighbour-matching method was used to optimize the matching results, and also to even the size of each group, the ratio was fixed to 1:1. We found that the matched groups showed no significant differences for the adjusted factors [7]. A P-value of <0.05 was considered statistically significant. RESULTS Early results There was no operative mortality. The mean postoperative mechanical ventilation time was 28.1 ± 19.3 h (range 10–109 h), and most of the patients (39 of 43 patients, 91%) were extubated within 48 h. The mean hospital stay was 9.9 ± 4.1 days (range 6–31 days). The mean postoperative PR grade at discharge was 0.93 ± 0.40 [none or trivial in 10 patients (23%), mild in 27 patients (63%), mild to moderate in 5 patients (12%) and moderate in 1 patient (2%)], and the mean postoperative pressure gradient (PG) across the PV was 13.0 ± 10.9 mmHg (range 5–43 mmHg). Of the 43 patients, only 1 (2%) patient had moderate PR at discharge. Late results The mean follow-up duration was 131.9 ± 42.9 months (range 29–198 months). During follow-up, 1 reoperation was performed for a residual VSD. Eight reinterventions were performed in 6 (14%) patients, and all reinterventions were balloon angioplasties for left pulmonary artery stenosis. There were 3 late deaths, but all late deaths were not related to cardiac origin. The causes of death were Fanconi anaemia, haemophagocytic syndrome and upper airway problem. The mean echocardiography follow-up duration was 123.7 ± 43.2 months (range 29–198 months). The mean PR grade at the last follow-up echocardiography was 1.59 ± 0.60 [mild in 17 patients (40%), mild to moderate in 8 patients (19%), moderate in 14 patients (33%), moderate to severe in 1 patient (2%) and severe in 3 patients (7%)], and the mean PG across the PV was 22.7 ± 9.9 mmHg (range 10–49 mmHg). Eighteen (42%) patients had moderate or more PR grade at the last follow-up echocardiography. PR grade (Fig. 2, P < 0.01) and PG across the PV (Fig. 3, P < 0.01) tended to increase with time. Risk factors for moderate or more PR grade at the last follow-up echocardiography were analysed, but we could not identify any risk factor for significant PR grade, except cardiopulmonary bypass time (Table 1). Table 1: Risk factor analysis for moderate or more PR at the last follow-up echocardiography Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 ACC: aortic cross-clamp; BT: Blalock–Taussig; CPB: cardiopulmonary bypass; MO: muscular outlet; PM: perimembranous; PR: pulmonary regurgitation; PTFE: polytetrafluoroethylene; PV: pulmonary valve; RA: right atrium; RV: right ventricle; SA: subarterial; SD: standard deviation; VSD: ventricular septal defect. Table 1: Risk factor analysis for moderate or more PR at the last follow-up echocardiography Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 Risk factors Less-than-moderate PR (n = 25, 58%) Moderate or more PR at the last follow-up echocardiography (n = 18, 42%) P-value Age (months), mean ± SD 16.8 ± 7.5 14.6 ± 5.1 0.29 Weight (kg), mean ± SD 10.3 ± 1.8 9.4 ± 1.8 0.12 Gender (male/female) 13/12 13/5 0.18 Previous BT shunt, n (%) 8 (32) 2 (11) 0.11 PV morphology (bicuspid/tricuspid) 23/2 14/4 0.18 PV annulus size (mm), mean ± SD 8.8 ± 1.1 8.9 ± 0.9 0.85 PV annulus z-score, mean ± SD −2.13 ± 0.85 −1.82 ± 0.87 0.25 Ventriculotomy size (mm), mean ± SD 11.8 ± 4.0 12.9 ± 2.9 0.33 VSD type (PM/SA/MO) 18/3/4 11/5/2 0.41 VSD closure route (RA/RV/RA + RV) 16/7/2 10/6/2 0.85 Used patch for PV reconstruction (pericardium/PTFE) 16/9 15/3 0.16 CPB time (min), mean ± SD 172.0 ± 32.1 150.4 ± 22.2 0.02 ACC time (min), mean ± SD 103.8 ± 12.8 106.3 ± 21.7 0.63 RV/systemic pressure ratio, mean ± SD 0.51 ± 0.10 0.46 ± 0.10 0.18 Ventilator time (h), mean ± SD 28.4 ± 22.5 27.7 ± 1.6 0.91 Hospital stay (days), mean ± SD 8.9 ± 2.0 11.3 ± 5.6 0.06 Echocardiography follow-up duration (months), mean ± SD 122.0 ± 43.5 126.2 ± 43.8 0.76 ACC: aortic cross-clamp; BT: Blalock–Taussig; CPB: cardiopulmonary bypass; MO: muscular outlet; PM: perimembranous; PR: pulmonary regurgitation; PTFE: polytetrafluoroethylene; PV: pulmonary valve; RA: right atrium; RV: right ventricle; SA: subarterial; SD: standard deviation; VSD: ventricular septal defect. Figure 2: View largeDownload slide Postoperative pulmonary regurgitation (PR) changes. Figure 2: View largeDownload slide Postoperative pulmonary regurgitation (PR) changes. Figure 3: View largeDownload slide Postoperative pressure gradient (PR) change through the pulmonary valve. Figure 3: View largeDownload slide Postoperative pressure gradient (PR) change through the pulmonary valve. Comparison with the simple transannular patch technique We have compared the present 43 patients with 63 patients who underwent transannular enlargement with a simple TAP technique between September 1996 and April 2011. The mean age and body weight at the time of surgery were 9.6 ± 5.1 months and 8.0 ± 2.0 kg, respectively. The mean follow-up duration was 88.0 ± 51.4 months. The 63 patients were divided into 2 subgroups: large ventriculotomy (>5 mm, n = 32, 51%) and limited ventriculotomy (≤5 mm, n = 31, 49%). On comparing with the large ventriculotomy group, the patients undergoing PV repair had lower PR grade at both immediate postoperative (P < 0.01) and the last follow-up (P = 0.02) echocardiography. On comparing with the limited ventriculotomy group, the patients undergoing PV repair had lower PR grade only at immediate postoperative echocardiography (P < 0.01). There was no significant difference between the 2 groups (P = 0.48) at the last follow-up echocardiography (Table 2). Figure 4 shows the mean postoperative PR grade changes in terms of the PV annulus enlargement technique: PV repair, large ventriculotomy and limited ventriculotomy. Of the 63 patients, 3 (5%) patients underwent PVR in the entire simple TAP group, whereas none of the patients required PVR in the PV repair group (Fig. 5, P = 0.11, log-rank test). Table 2: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique depending on the ventriculotomy size PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c The values in parentheses for the “Last PR grade (moderate or more PR)” indicate the number of patients who have moderate or more PR grade at the last F/U echocardiography. a Reoperation due to residual VSD closure. b Reoperation due to PVR in 2 patients and pacemaker insertion in 1 patient. c Reoperation due to PVR in 1 patient and aortopexy in 1 patient. * P < 0.05: PV repair versus large ventriculotomy (>5 mm). ** P < 0.05: PV repair versus limited ventriculotomy (≤5 mm). ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; PVR: pulmonary valve replacement; SD: standard deviation; TAP: transannular patch; VSD: ventricular septal defect. Table 2: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique depending on the ventriculotomy size PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c PV repair (n = 43) Simple TAP (large ventriculotomy, >5 mm, n = 32) Simple TAP (limited ventriculotomy, ≤5 mm, n = 31) Age (months), mean ± SD 15.9 ± 6.6 11.1 ± 4.4* 8.0 ± 5.2** Weight (kg), mean ± SD 9.9 ± 1.8 8.5 ± 1.9* 7.5 ± 1.9** Gender (male/female) 26/17 20/12 17/14 PV annulus size (mm), mean ± SD 8.8 ± 1.0 7.3 ± 1.6* 7.7 ± 1.1** PV annulus z-score, mean ± SD −2.00 ± 0.86 −2.86 ± 1.52* −2.19 ± 0.71 Ventriculotomy size (mm), mean ± SD 12.3 ± 3.6 11.0 ± 3.3 3.9 ± 1.3** CPB time (min), mean ± SD 163.0 ± 30.1 175.9 ± 37.3 157.1 ± 34.2 ACC time (min), mean ± SD 104.8 ± 17.0 97.3 ± 24.6 104.3 ± 21.4 Ventilator time (h), mean ± SD 28.1 ± 19.3 58.9 ± 71.2* 45.1 ± 51.1 Hospital stay (days), mean ± SD 9.9 ± 4.1 12.4 ± 11.2 12.9 ± 6.1** Immediate postoperative PR, mean ± SD 0.93 ± 0.40 1.94 ± 0.64* 1.48 ± 0.66** F/U duration (months), mean ± SD 131.9 ± 42.9 104.7 ± 63.2* 70.8 ± 26.8** Echocardiography F/U duration (months), mean ± SD 123.7 ± 43.2 94.3 ± 58.7* 66.7 ± 28.2** Last PR grade (moderate or more PR), mean ± SD 1.59 ± 0.60 (18, 42%) 1.97 ± 0.74 (23, 72%)* 1.69 ± 0.61 (16, 52%) Last PG across PV (mmHg), mean ± SD 22.7 ± 9.9 18.6 ± 11.3 21.0 ± 11.4 Last F/U CT ratio, mean ± SD 0.54 ± 0.07 0.56 ± 0.05 0.57 ± 0.04** Reoperation, n (%) 1 (2)a 3 (9)b 2 (7)c The values in parentheses for the “Last PR grade (moderate or more PR)” indicate the number of patients who have moderate or more PR grade at the last F/U echocardiography. a Reoperation due to residual VSD closure. b Reoperation due to PVR in 2 patients and pacemaker insertion in 1 patient. c Reoperation due to PVR in 1 patient and aortopexy in 1 patient. * P < 0.05: PV repair versus large ventriculotomy (>5 mm). ** P < 0.05: PV repair versus limited ventriculotomy (≤5 mm). ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; PVR: pulmonary valve replacement; SD: standard deviation; TAP: transannular patch; VSD: ventricular septal defect. Figure 4: View largeDownload slide Postoperative pulmonary regurgitation change depending on each technique. F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Figure 4: View largeDownload slide Postoperative pulmonary regurgitation change depending on each technique. F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Figure 5: View largeDownload slide Freedom from pulmonary valve replacement (PVR). F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Figure 5: View largeDownload slide Freedom from pulmonary valve replacement (PVR). F/U: follow-up; PV: pulmonary valve; TAP: transannular patch. Using propensity score matching, 25 patients who underwent PV repair and 25 patients who underwent the simple TAP technique were selected. Baseline balance was assessed by standardized differences. Each group was well balanced with respect to age and body weight at surgery, PV annulus size and echocardiography follow-up duration (Table 3). The PV repair group had a lower incidence of moderate or more PR grade at the last follow-up echocardiography compared with the simple TAP group (40% vs 68%, P = 0.04). Table 3: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique using propensity score matching PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 a Matching elements. ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; SD: standard deviation; TAP: transannular patch. Table 3: Comparison of the pulmonary valve repair technique with the simple transannular patch enlargement technique using propensity score matching PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 PV repair (n = 25) Simple TAP (n = 25) P-value Age (months),a mean ± SD 15.2 ± 73 12.0 ± 5.4 0.09 Weight (kg),a mean ± SD 9.6 ± 1.8 8.8 ± 2.4 0.18 Gender (male/female) 18/7 17/8 0.76 PV annulus size (mm),a mean ± SD 8.8 ± 1.1 8.1 ± 1.6 0.08 PV annulus z-score, mean ± SD −1.92 ± 0.89 −2.27 ± 1.47 0.31 Ventriculotomy size (mm), mean ± SD 12.4 ± 3.7 9.4 ± 4.9 0.02 CPB time (min), mean ± SD 160.4 ± 30.6 167.0 ± 34.9 0.48 ACC time (min), mean ± SD 104.4 ± 12.1 95.2 ± 22.1 0.07 Ventilation time (h), mean ± SD 30.2 ± 22.8 62.8 ± 89.0 0.09 Hospital stay (days), mean ± SD 9.7 ± 2.6 13.8 ± 12.9 0.13 Immediate postoperative PR, mean ± SD 0.94 ± 0.36 1.70 ± 0.69 <0.01 F/U duration (months), mean ± SD 130.4 ± 44.8 115.9 ± 58.9 0.33 Echocardiography F/U duration (months),a mean ± SD 121.0 ± 43.6 110.6 ± 55.8 0.47 Last PR grade, mean ± SD 1.54 ± 0.58 1.94 ± 0.78 0.04 Last PR ≥moderate, n (%) 10 (40) 17 (68) 0.04 Last PG across PV (mmHg), mean ± SD 24.0 ± 8.4 17.6 ± 8.7 0.01 Last F/U CT ratio, mean ± SD 0.55 ± 0.07 0.54 ± 0.04 0.87 a Matching elements. ACC: aortic cross-clamp; CPB: cardiopulmonary bypass; CT: computed tomography; F/U: follow-up; PG: pressure gradient; PR: pulmonary regurgitation; PV: pulmonary valve; SD: standard deviation; TAP: transannular patch. DISCUSSION The incidence of TAP enlargement in the repair of TOF has decreased after the introduction of several PV preservation strategies [6, 8–12]. However, a certain proportion of patients with a small PV annulus have required TAP enlargement. The TAP enlargement inevitably produces postoperative PR, which can adversely affect the long-term results of TOF correction [13, 14]. TAP with MVOP has been the main surgical technique to reduce postoperative PR. However, valve function of the MVOP does not persist for a long time [15–19]. In our opinion, the valve function of our PV repair technique lasts longer than the valve function of the MVOP technique because the repaired valve can retain partial or complete native hinge function, even though the mechanism of limited longevity of the MVOP remains unclear. The main purpose of our repair policy of the PV is to preserve the native hinge function of the PV as well as to preserve the native PV tissues as much as possible. We think that the patch attached to the native valve cusp that has the hinge function can hardly adhere to the outer RVOT patch unlike in the MVOP in which the valve cusp without the native valve hinge function can adhere to the outer patch easily. In addition to preserving the native PV hinge function, the valve repair technique has an important advantage over the MVOP in terms of technical flexibility. In contrast to MVOP, it allows the technique to be used even when only a small enlargement of the PV annulus is needed. The MVOP procedure usually requires a relatively large RVOT incision, which is a potential source of a late problem when the valve function of the MVOP disappears. However, after the valve repair, we expect the growth of the remaining repaired native valve tissue that is functioning. We postulate that functioning PV tissues would grow more than non-functioning valve tissues. During the early postoperative period, only 1 (2%) patient had moderate PR, and the PG across the PV was not significant (13.0 ± 10.9 mmHg). Although PR tended to increase over the long-term follow-up (Fig. 2), approximately 40% of the patients retained mild PR long after the surgery, which was believed to be an important contribution of the PV repair technique. There was also a tendency of increasing PG across the PV, but the mean PG across the PV was not significant (22.7 ± 9.9 mmHg) over the ensuing 123.7 ± 43.2 months of echocardiography follow-up (Fig. 3). We compared the outcomes of these patients with those of the 63 patients who had undergone the simple TAP technique. The patients were divided into limited and large ventriculotomy subgroups in terms of the ventriculotomy size. The patients who underwent PV repair had lower PR grade at the immediate postoperative period when compared with both subgroups. However, at the last follow-up, the PV repair group had lower PR grade when compared with the large ventriculotomy group but not when compared with the limited ventriculotomy group (Table 2). The identical degree of PR between the PV repair and the limited TAP groups indicates that both techniques can reduce PR when compared with TAP enlargement with a large incision. The mechanism to reduce PR in both techniques seems to be quite different, and we also need to be aware of the difference in follow-up duration between these 2 techniques (Fig. 4). Propensity score matching was used to compare postoperative PR between the PV repair and the simple TAP technique. Lower immediate postoperative PR grade and lower incidence of moderate or more PR grade at the last follow-up echocardiography were evident in the patients who underwent the PV repair technique. Although a statistically significant difference was not observed, none of the patients needed PVR in the PV repair group, while 3 (5%) patients required PVR in the simple TAP group. Most of the patients had a good PV motion on early postoperative echocardiography at discharge, which was consistent with a previous study [4]. However, in some patients, the valve motion was decreased or absent at the follow-up echocardiography, and shrinkage and thickening of the reconstructed PV cusp were evident. This prompted us to change the patch material from glutaraldehyde-treated autologous pericardium to a 0.1-mm PTFE membrane and to reduce the target annulus size to minimize the ventriculotomy size. There was no statistically significant difference in the incidence of moderate or more PR grade at the last follow-up echocardiography in terms of the 2 patch materials. However, more patients who underwent PV repair using the glutaraldehyde-treated autologous pericardial patch had moderate or more PR grade at the last follow-up echocardiography [15/31 (48%) vs 3/12 (25%); P = 0.16]. An important limitation of the PV repair technique is that it is somewhat difficult to apply to a small baby with a small PV or friable valve tissue. Thus, the technique has not been used frequently in our hospital because our policy for TOF correction was changed to early repair with maximization of PV and RVOT preservation, in which nearly all patients with TOF are repaired between 3 months and 6 months of age. Instead, we have usually performed a small transannular ventriculotomy when TAP enlargement is required. However, we have currently started the PV repair technique even in a small infant patient who requires a small transannular ventriculotomy as inspired by the favourable long-term results of the PV repair. The target PV annulus size in our current practice is just the normal size or 1 mm below the normal size in the arrested heart to minimize the ventriculotomy. The strategy that has also been established is that as the age at TOF repair becomes younger, the PV annulus can be preserved in approximately 70% of all patients with TOF [20]. However, we have been concentrating on the preservation of the PV annulus and RVOT muscle rather than the preservation of the valve tissue itself. In fact, it is very difficult to preserve the valve function completely in small bicuspid PV. We believe that the amount of valve function that can be preserved mainly depends on the native valve morphology. In a patient with small PV annulus having anterior and posterior commissures, we usually perform commissurotomy and small ventriculotomy through the anterior commissure. However, if the patients have the right and left commissures with sizeable and good anterior valve cusp, we place a fresh autologous pericardial patch between the divided anterior cusps, regardless of the ventriculotomy size in a small baby. A fresh autologous pericardial patch is used because of technical considerations. It is technically demanding to use a 0.1-mm PTFE membrane for repair of the small valve cusp in a small baby with TOF. We use a 0.1-mm PTFE membrane for repair of the PV in large-sized or old patients with TOF who require a long right ventricular incision. We believe that the same favourable long-term result can be expected in a young infant in spite of the fact that the PV repair is technically more demanding. Karl and colleagues [21] reported early results of PV repair in 2007. The patients in their study were much younger than our series. Although the tissue or the material used in valve repair can be thickened or shrunk, the repaired remaining native PV tissue still has growth potential, which could reduce PR to some extent. However, in reality, it is sometimes technically demanding to repair small valve cusps and even more demanding in dysplastic small valve cusps. Our study demonstrates that patients who require TAP enlargement could benefit from the valve repair technique in terms of reduction of the PR in the long term and that the feasibility of the valve repair technique in a small baby is dependent on the surgeon’s hand. Limitations The limitations of this study include a relatively small number of patients and the lack of a proper comparative group of patients. Because this was neither a prospective nor a case–control study, the patients were not matched for demographic data. To overcome this limitation, we used the propensity score matching method. CONCLUSION In conclusion, PV annular enlargement with valve repair technique in TOF correction provides excellent valve function in the early postoperative period and also reduces late postoperative PR. Funding This work was supported by a 2-year research grant from the Pusan National University. Conflict of interest: none declared. REFERENCES 1 Ellison RG , Brown WJ Jr , Yeh TJ , Hamilton WF. Surgical significance of acute and chronic pulmonary valvular insufficiency . J Thorac Cardiovasc Surg 1970 ; 60 : 549 – 58 . Google Scholar PubMed 2 Geva T , Sandweiss BM , Gauvreau K , Lock JE , Powell AJ. Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging . J Am Coll Cardiol 2004 ; 43 : 1068 – 74 . Google Scholar CrossRef Search ADS PubMed 3 Helbing WA , Niezen RA , Le Cessie S , van der Geest RJ , Ottenkamp J , de Roos A. Right ventricular diastolic function in children with pulmonary regurgitation after repair of tetralogy of Fallot: volumetric evaluation by magnetic resonance velocity mapping . J Am Coll Cardiol 1996 ; 28 : 1827 – 35 . Google Scholar CrossRef Search ADS PubMed 4 Sung SC , Kim S , Woo JS , Lee YS. Pulmonic valve annular enlargement with valve repair in tetralogy of Fallot . Ann Thorac Surg 2003 ; 75 : 303 – 5 . Google Scholar CrossRef Search ADS PubMed 5 Kouchoukos NT , Blackstone EH , Hanley FL , Kirklin JK. Kirklin/Barratt-Boyes Cardiac Surgery . 4th edn . Philadelphia, PA : Saunders , 2013 , 34 . 6 Ito H , Ota N , Murata M , Tosaka Y , Ide Y , Tachi M et al. Technical modification enabling pulmonary valve-sparing repair of a severely hypoplastic pulmonary annulus in patients with tetralogy of Fallot . Interact CardioVasc Thorac Surg 2013 ; 16 : 802 – 7 . Google Scholar CrossRef Search ADS PubMed 7 Ho DE , Imai K , King C , Stuart EA. Matching as nonparametric preprocessing for reducing model dependence in parametric causal Inference . Polit Anal 2007 ; 15 : 199 – 236 . Google Scholar CrossRef Search ADS 8 Bacha E. Valve-sparing options in tetralogy of Fallot surgery . Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2012 ; 15 : 24 – 6 . Google Scholar CrossRef Search ADS PubMed 9 Kawashima Y , Kitamura S , Nakano S , Yagihara T. Corrective surgery for tetralogy of Fallot without or with minimal right ventriculotomy and with repair of the pulmonary valve . Circulation 1981 ; 64 : II147 – 53 . Google Scholar PubMed 10 Mavroudis CD , Frost J , Mavroudis C. Pulmonary valve preservation and restoration strategies for repair of tetralogy of Fallot . Cardiol Young 2014 ; 24 : 1088 – 94 . Google Scholar CrossRef Search ADS PubMed 11 Bacha E. Valve-sparing or valve reconstruction options in tetralogy of Fallot surgery . Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2017 ; 20 : 79 – 83 . Google Scholar CrossRef Search ADS PubMed 12 Vida VL , Guariento A , Zucchetta F , Padalino M , Castaldi B , Milanesi O et al. Preservation of the pulmonary valve during early repair of tetralogy of Fallot: surgical techniques . Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2016 ; 19 : 75 – 81 . Google Scholar CrossRef Search ADS PubMed 13 Carvalho JS , Shinebourne EA , Busst C , Rigby ML , Redington AN. Exercise capacity after complete repair of tetralogy of Fallot: deleterious effects of residual pulmonary regurgitation . Br Heart J 1992 ; 67 : 470 – 3 . Google Scholar CrossRef Search ADS PubMed 14 Kirklin JK , Kirklin JW , Blackstone EH , Milano A , Pacifico AD. Effect of transannular patching on outcome after repair of tetralogy of Fallot . Ann Thorac Surg 1989 ; 48 : 783 – 91 . Google Scholar CrossRef Search ADS PubMed 15 Bigras JL , Boutin C , McCrindle BW , Rebeyka IM. Short-term effect of monocuspid valves on pulmonary insufficiency and clinical outcome after surgical repair of tetralogy of Fallot . J Thorac Cardiovasc Surg 1996 ; 112 : 33 – 7 . Google Scholar CrossRef Search ADS PubMed 16 Gundry SR , Razzouk AJ , Boskind JF , Bansal R , Bailey LL. Fate of the pericardial monocusp pulmonary valve for right ventricular outflow tract reconstruction. Early function, late failure without obstruction . J Thorac Cardiovasc Surg 1994 ; 107 : 908 – 12 ; discussion 12–3. Google Scholar PubMed 17 Kim H , Sung SC , Kim SH , Chang YH , Lee HD , Park JA et al. Early and late outcomes of total repair of tetralogy of Fallot: risk factors for late right ventricular dilatation . Interact CardioVasc Thorac Surg 2013 ; 17 : 956 – 62 . Google Scholar CrossRef Search ADS PubMed 18 Park CS , Lee JR , Lim HG , Kim WH , Kim YJ. The long-term result of total repair for tetralogy of Fallot . Eur J Cardiothorac Surg 2010 ; 38 : 311 – 7 . Google Scholar CrossRef Search ADS PubMed 19 Jang WS , Cho JY , Lee JU , Lee Y. Surgical results of monocusp implantation with transannular patch angioplasty in tetralogy of Fallot repair . Korean J Thorac Cardiovasc Surg 2016 ; 49 : 344 – 9 . Google Scholar CrossRef Search ADS PubMed 20 Choi KH , Sung SC , Kim H , Lee HD , Ban GH , Kim G et al. A novel predictive value for the transannular patch enlargement in repair of tetralogy of Fallot . Ann Thorac Surg 2016 ; 101 : 703 – 7 . Google Scholar CrossRef Search ADS PubMed 21 Anagnostopoulos P , Azakie A , Natarajan S , Alphonso N , Brook MM , Karl TR. Pulmonary valve cusp augmentation with autologous pericardium may improve early outcome for tetralogy of Fallot . J Thorac Cardiovasc Surg 2007 ; 133 : 640 – 7 . Google Scholar CrossRef Search ADS PubMed © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)

Journal

European Journal of Cardio-Thoracic SurgeryOxford University Press

Published: Jan 22, 2018

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off