TY - JOUR
AU - Sommer,, Sebastian-Patrick
AB - Abstract OBJECTIVES In contrast to stented transcatheter aortic valves, the Direct Flow Medical (DFM) valve is a stentless bovine aortic bioprosthesis mounted in a non-metallic inflatable frame. Hence, severe asymmetric annular calcification may result in residually elevated transaortic pressure gradients after DFM implantation. We present a novel intraprocedural dilatation (IDIL) technique for successful implantation of the DFM valve in the presence of complex annular calcification. METHODS Between January 2014 and May 2015, 55 patients underwent DFM valve-based transcatheter aortic valve implantation at our institution. Of these, 5 patients required an IDIL technique due to a residual intraoperative transaortic pressure mean gradient above 15 mmHg. The mean patient age was 73 ± 8.2 years; the mean logistic EuroSCORE was 24.5 ± 8.2% and the mean Society of Thoracic Surgeons score was 6.3 ± 4.3%. RESULTS The IDIL technique immediately attenuated transvalvular mean pressure gradients from 20 ± 2 mmHg to 6 ± 1 mmHg. The results remained stable during the 30-day observation period at 10 ± 3 mmHg. Minimal paravalvular aortic regurgitation (trace) was detected in 2 patients. No in-hospital deaths were observed. CONCLUSIONS The IDIL technique facilitates safe DFM valve implantation in patients with complex asymmetric annular calcification without adverse side effects on valve structure or performance in short-term follow-up. Aortic valve stenosis, Paravalvular leack, Transcatheter aortic valve implantation, Valvuloplasty INTRODUCTION Transcatheter aortic valve implantation (TAVI) has become an accepted treatment for aortic valve stenosis in high-risk patients [1–3]. In contrast to conventional TAVI valve prostheses that are supported by a metal framework, the Direct Flow Medical (DFM) valve (Direct Flow Medical, Santa Rosa, CA, USA) consists of an inflatable Dacron-polyester double-ring design, containing non-compliant angioplasty balloon technology [4]. A cylindrical bridge connects the upper (aortic) and lower (ventricular) balloon rings. Hollow positioning wires independently pressurize the cylinders. Upon pressurization, the lateral struts connecting the 2 rings exert a radial opening force via the cylindrical part. Complete valve expansion results, with the lateral struts perpendicular to the 2 rings (Fig. 1C). Figure 1: Open in new tabDownload slide The 3 steps of the intraprocedural dilatation technique. (A) Deflation of DFM upper ring during balloon inflation; (B) DFM inflation while the balloon is maximally expanded; (C) balloon deflation. DFM: Direct Flow Medical. Figure 1: Open in new tabDownload slide The 3 steps of the intraprocedural dilatation technique. (A) Deflation of DFM upper ring during balloon inflation; (B) DFM inflation while the balloon is maximally expanded; (C) balloon deflation. DFM: Direct Flow Medical. In standard metal-stented valves, severe asymmetric calcification hinders complete expansion of the valve frame and thus comes with an increased risk for paravalvular regurgitation [5, 6]. In this scenario, the flexibility of the DFM prosthesis allows improved adaptation of the lower ring to the native valve, reducing the incidence of paravalvular leak (PVL) [7]. However, extreme calcification may resist the opening force exerted by pressurization of the DFM prosthesis (Video 1) and results in residual transaortic pressure gradients. To overcome the increased transaortic gradients, we established a new intraprocedural dilatation (IDIL) technique. Video 1: Incomplete expansion of the Direct Flow Medical cylindrical bridge, resulting in elevated transvalvular pressure gradients. Video 1: Incomplete expansion of the Direct Flow Medical cylindrical bridge, resulting in elevated transvalvular pressure gradients. Close MATERIALS AND METHODS Patient characteristics Between January 2014 and May 2015, 55 patients underwent DFM implantation. Table 1 presents preoperative patient characteristics. Of those, 5 patients required IDIL. Preoperative imaging included coronary angiography, echocardiography and computed tomography. A dedicated software (3mensio Medical Imaging, B.V., Bilthoven, Netherland) analysed the data for native valve calcification, iliofemoral vessels and valve diameter. A multidisciplinary heart team selected the valve size and access route. Table 1: Demographics and baseline characteristics of the patient cohort Baseline characteristics Mean ± SD or n (%) Number of patients 5 Age (years) 73 ± 8.2 Male gender 2 (40) Logistic EuroSCORE 24.5 ± 8.2 STS predicted risk of mortality 6.3 ± 4.3 BMI (kg/m2) 30 ± 5 NYHA Class >II 5 (100) Hypertension 5 (100) Diabetes 5 (100) Chronic renal failure ≥Stage 3 1 (20) Peripheral artery disease 2 (40) Coronary artery disease 2 (40) Prior PCI 1 (20) Prior CABG 1 (20) Atrial fibrillation 3 (60) Prior pacemaker implantation 0 Prior stroke 0 Left ventricular ejection fraction 35 ± 16 Preoperative haemoglobin level (g/dl) 12.7 ± 2 Transaortic mean gradient (mmHg) 46 ± 25.3 Aortic regurgitation (≥2) 1 (20) Mitral regurgitation (≥2) 3 (60) Baseline characteristics Mean ± SD or n (%) Number of patients 5 Age (years) 73 ± 8.2 Male gender 2 (40) Logistic EuroSCORE 24.5 ± 8.2 STS predicted risk of mortality 6.3 ± 4.3 BMI (kg/m2) 30 ± 5 NYHA Class >II 5 (100) Hypertension 5 (100) Diabetes 5 (100) Chronic renal failure ≥Stage 3 1 (20) Peripheral artery disease 2 (40) Coronary artery disease 2 (40) Prior PCI 1 (20) Prior CABG 1 (20) Atrial fibrillation 3 (60) Prior pacemaker implantation 0 Prior stroke 0 Left ventricular ejection fraction 35 ± 16 Preoperative haemoglobin level (g/dl) 12.7 ± 2 Transaortic mean gradient (mmHg) 46 ± 25.3 Aortic regurgitation (≥2) 1 (20) Mitral regurgitation (≥2) 3 (60) BMI: body mass index; CABG: coronary artery bypass grafting; NYHA: New York Heart Association; PCI: percutaneous coronary intervention; STS: Society of Thoracic Surgeons. Table 1: Demographics and baseline characteristics of the patient cohort Baseline characteristics Mean ± SD or n (%) Number of patients 5 Age (years) 73 ± 8.2 Male gender 2 (40) Logistic EuroSCORE 24.5 ± 8.2 STS predicted risk of mortality 6.3 ± 4.3 BMI (kg/m2) 30 ± 5 NYHA Class >II 5 (100) Hypertension 5 (100) Diabetes 5 (100) Chronic renal failure ≥Stage 3 1 (20) Peripheral artery disease 2 (40) Coronary artery disease 2 (40) Prior PCI 1 (20) Prior CABG 1 (20) Atrial fibrillation 3 (60) Prior pacemaker implantation 0 Prior stroke 0 Left ventricular ejection fraction 35 ± 16 Preoperative haemoglobin level (g/dl) 12.7 ± 2 Transaortic mean gradient (mmHg) 46 ± 25.3 Aortic regurgitation (≥2) 1 (20) Mitral regurgitation (≥2) 3 (60) Baseline characteristics Mean ± SD or n (%) Number of patients 5 Age (years) 73 ± 8.2 Male gender 2 (40) Logistic EuroSCORE 24.5 ± 8.2 STS predicted risk of mortality 6.3 ± 4.3 BMI (kg/m2) 30 ± 5 NYHA Class >II 5 (100) Hypertension 5 (100) Diabetes 5 (100) Chronic renal failure ≥Stage 3 1 (20) Peripheral artery disease 2 (40) Coronary artery disease 2 (40) Prior PCI 1 (20) Prior CABG 1 (20) Atrial fibrillation 3 (60) Prior pacemaker implantation 0 Prior stroke 0 Left ventricular ejection fraction 35 ± 16 Preoperative haemoglobin level (g/dl) 12.7 ± 2 Transaortic mean gradient (mmHg) 46 ± 25.3 Aortic regurgitation (≥2) 1 (20) Mitral regurgitation (≥2) 3 (60) BMI: body mass index; CABG: coronary artery bypass grafting; NYHA: New York Heart Association; PCI: percutaneous coronary intervention; STS: Society of Thoracic Surgeons. Implant supported by intraprocedural dilatation Indications for the IDIL technique included a postimplantation transaortic pressure gradient above 15 mmHg, incomplete valve expansion or a non-circular upper ring suggestive of inadequate capture of the native leaflet. We performed the IDIL technique after 2 failed valve-repositioning attempts. In contrast to post-dilatation of conventional TAVI valves, performed after implantation of a valve prosthesis, the IDIL technique constitutes an optional step within the primary implant procedure. Therefore, additional vascular access is mandatory to advance the valvuloplasty balloon. The diagnostic access sheath placed in the contralateral femoral artery is exchanged with a 12-Fr interventional access sheath. The lower ring of the DFM prosthesis is pulled into the optimal position. A valvuloplasty balloon is placed via a stiff guidewire inside the DFM prosthesis (Video 2). The same balloon used for the original valvuloplasty was chosen for prosthesis dilatation. Under rapid pacing and slow balloon inflation, the DFM upper ring is deflated (Fig. 1A). After reaching the maximum expansion of the balloon, the upper ring is reinflated in its final position (Fig. 1B). Under this protection, the angioplasty balloon is deflated, and rapid pacing is terminated (Fig. 1C). Video 2: Intraprocedural dilatation to achieve complete cylindrical bridge expansion of the Direct Flow Medical valve, normalizing transvalvular pressure gradients. Video 2: Intraprocedural dilatation to achieve complete cylindrical bridge expansion of the Direct Flow Medical valve, normalizing transvalvular pressure gradients. Close After the balloon is withdrawn, a pigtail catheter replaces the stiff guidewire to determine the transvalvular pressure gradient. The procedures were completed according to standard implant techniques [4, 7]. RESULTS Patients Five patients were treated using the IDIL technique. Three patients underwent valve implantation and the IDIL technique transfemorally; in 1 patient, valve implantation was performed via direct aortic access with the IDIL technique performed trans-femorally; in the 5th case, the procedures were performed via the direct aortic access route. Table 2 demonstrates valvular calcification patterns. Anatomy and access route were not predictive of the need for the IDIL technique. The presence of asymmetric calcification of the native valve appeared to be predictive. Intraoperative results exclusively determined the decision to perform the IDIL technique. Table 2: Intraprocedural characteristics and results Patient Agatston score Mass score (mg) Visual examination 1 4125 676 Severe 2 4888 1188 Moderate to severe 3 3842 679 Moderate 4 4734 866 Moderate to severe 5 4556 896 Severe Patient Agatston score Mass score (mg) Visual examination 1 4125 676 Severe 2 4888 1188 Moderate to severe 3 3842 679 Moderate 4 4734 866 Moderate to severe 5 4556 896 Severe Table 2: Intraprocedural characteristics and results Patient Agatston score Mass score (mg) Visual examination 1 4125 676 Severe 2 4888 1188 Moderate to severe 3 3842 679 Moderate 4 4734 866 Moderate to severe 5 4556 896 Severe Patient Agatston score Mass score (mg) Visual examination 1 4125 676 Severe 2 4888 1188 Moderate to severe 3 3842 679 Moderate 4 4734 866 Moderate to severe 5 4556 896 Severe Perioperative and postoperative outcomes Perioperative and postoperative results are presented in Table 3. We used a 20-mm and a 22-mm balloon to dilate two 23-mm valves, and a 22-mm, a 24-mm and a 26-mm balloon in the 25-mm, 27-mm, and 29-mm valves, respectively. The mean procedure time was 160 ± 34 min, with a mean fluoroscopy time of 30 ± 7.9 min. The average amount of contrast agent given was 139 ± 45 ml. Four patients were extubated immediately after the procedure. One patient required prolonged mechanical ventilation due to the preoperative onset of cardiac decompensation and pneumonia. This patient was discharged to a rehabilitation centre in good condition 13 days after TAVI. Table 3: Procedural characteristics, post-procedural outcomes and complication rates Procedural characteristics and post-procedural outcomes Mean ± SD or n (%) Patient number 5 Procedural duration (min) 160 ± 34 Contrast agent (ml) 139 ± 45 Fluoroscopy time (min) 30 ± 7.9 Mean transaortic pressure gradient preintraprocedural dilatation technique (mmHg) 20 ± 2 Mean transaortic pressure gradient postintraprocedural dilatation technique (mmHg) 6 ± 1 Mean transaortic pressure gradient 30 days postintraprocedural dilatation technique (mmHg) 10 ± 3 Moderate and severe paravalvular regurgitation 0 (0) VARC 2 device success 5 (100) Retrieval and second valve implanted 0 (0) Conversion to SAVR 0 (0) Patients extubated in OR 4 (80) Intraoperative mortality 0 (0) Major vascular complication 0 (0) Life-threatening bleeding 0 (0) Transfusion (units PRBC) 2 ± 2.2 Myocardial infarction 0 (0) Stroke 0 (0) Intensive care unit stay, days [median (IQR)] 2.0 (1–13) Permanent pacemaker implantation 0 (0) Reintervention 0 (0) Acute kidney injury, Stage >3 1 (20) Hospital stay, days [median (IQR)] 14 (13–16) All-cause mortality (30 days) 0 Procedural characteristics and post-procedural outcomes Mean ± SD or n (%) Patient number 5 Procedural duration (min) 160 ± 34 Contrast agent (ml) 139 ± 45 Fluoroscopy time (min) 30 ± 7.9 Mean transaortic pressure gradient preintraprocedural dilatation technique (mmHg) 20 ± 2 Mean transaortic pressure gradient postintraprocedural dilatation technique (mmHg) 6 ± 1 Mean transaortic pressure gradient 30 days postintraprocedural dilatation technique (mmHg) 10 ± 3 Moderate and severe paravalvular regurgitation 0 (0) VARC 2 device success 5 (100) Retrieval and second valve implanted 0 (0) Conversion to SAVR 0 (0) Patients extubated in OR 4 (80) Intraoperative mortality 0 (0) Major vascular complication 0 (0) Life-threatening bleeding 0 (0) Transfusion (units PRBC) 2 ± 2.2 Myocardial infarction 0 (0) Stroke 0 (0) Intensive care unit stay, days [median (IQR)] 2.0 (1–13) Permanent pacemaker implantation 0 (0) Reintervention 0 (0) Acute kidney injury, Stage >3 1 (20) Hospital stay, days [median (IQR)] 14 (13–16) All-cause mortality (30 days) 0 VARC: Valve Academic Research Consortium; OR: operating room; PRBC: packed red blood cells; SAVR: surgical aortic valve replacement; IQR: interquartile range. Table 3: Procedural characteristics, post-procedural outcomes and complication rates Procedural characteristics and post-procedural outcomes Mean ± SD or n (%) Patient number 5 Procedural duration (min) 160 ± 34 Contrast agent (ml) 139 ± 45 Fluoroscopy time (min) 30 ± 7.9 Mean transaortic pressure gradient preintraprocedural dilatation technique (mmHg) 20 ± 2 Mean transaortic pressure gradient postintraprocedural dilatation technique (mmHg) 6 ± 1 Mean transaortic pressure gradient 30 days postintraprocedural dilatation technique (mmHg) 10 ± 3 Moderate and severe paravalvular regurgitation 0 (0) VARC 2 device success 5 (100) Retrieval and second valve implanted 0 (0) Conversion to SAVR 0 (0) Patients extubated in OR 4 (80) Intraoperative mortality 0 (0) Major vascular complication 0 (0) Life-threatening bleeding 0 (0) Transfusion (units PRBC) 2 ± 2.2 Myocardial infarction 0 (0) Stroke 0 (0) Intensive care unit stay, days [median (IQR)] 2.0 (1–13) Permanent pacemaker implantation 0 (0) Reintervention 0 (0) Acute kidney injury, Stage >3 1 (20) Hospital stay, days [median (IQR)] 14 (13–16) All-cause mortality (30 days) 0 Procedural characteristics and post-procedural outcomes Mean ± SD or n (%) Patient number 5 Procedural duration (min) 160 ± 34 Contrast agent (ml) 139 ± 45 Fluoroscopy time (min) 30 ± 7.9 Mean transaortic pressure gradient preintraprocedural dilatation technique (mmHg) 20 ± 2 Mean transaortic pressure gradient postintraprocedural dilatation technique (mmHg) 6 ± 1 Mean transaortic pressure gradient 30 days postintraprocedural dilatation technique (mmHg) 10 ± 3 Moderate and severe paravalvular regurgitation 0 (0) VARC 2 device success 5 (100) Retrieval and second valve implanted 0 (0) Conversion to SAVR 0 (0) Patients extubated in OR 4 (80) Intraoperative mortality 0 (0) Major vascular complication 0 (0) Life-threatening bleeding 0 (0) Transfusion (units PRBC) 2 ± 2.2 Myocardial infarction 0 (0) Stroke 0 (0) Intensive care unit stay, days [median (IQR)] 2.0 (1–13) Permanent pacemaker implantation 0 (0) Reintervention 0 (0) Acute kidney injury, Stage >3 1 (20) Hospital stay, days [median (IQR)] 14 (13–16) All-cause mortality (30 days) 0 VARC: Valve Academic Research Consortium; OR: operating room; PRBC: packed red blood cells; SAVR: surgical aortic valve replacement; IQR: interquartile range. The transvalvular mean pressure gradient before use of the IDIL technique was 20 ± 2 mmHg, despite 2 attempts to optimize the DFM position. After the IDIL technique, the mean pressure gradient dropped to 6 ± 1 mmHg. Thirty days after TAVI, the mean gradient remained stable at 10 ± 3 mmHg. Paravalvular aortic regurgitation was absent in 3 patients, and a trace was observed in 2 patients. Device success, as defined by the Valve Academic Research Consortium 2 [8], was achieved in 100% (n = 5) of patients. There was no need for a permanent pacemaker, and no stroke occurred. All patients were discharged and survived the first 30 days. Functional capacity and New York Heart Association functional class improved in all patients. DISCUSSION We demonstrated that the DFM IDIL technique, as part of the implantation procedure, reduces a residual transprosthetic gradient in the presence of relevant annular calcification. As demonstrated earlier, annular calcification in our cohort appeared to be an independent predictor for PVL after TAVI [9], since all patients subjected to the IDIL technique presented with an increased aortic calcification pattern (Table 1). Focusing on DFM-based TAVI, Krishnaswamy et al. [10] described the impact of annular calcification on valve underexpansion, resulting in PVL and the possibility of intraprocedural balloon dilation. In contrast to postimplantation valvuloplasty of a standard metal frame to optimize valve expansion, to reduce PVLs and to minimize residual transvalvular pressure gradients, the DFM IDIL technique comprises an optional but integral part of the procedure. Using our technique, the DFM prosthesis is expanded with the balloon, with the calcified area being protected by the covered valve prosthesis. Inflation of the balloon counteracts the calcific restriction during valve deployment, ensuring optimal valve expansion. To avoid a detrimental impact on valve integrity, we used the same balloon size as was used for the initial valvuloplasty for intraprosthetic balloon inflations with valvuloplasty balloons at least 2 mm smaller than the DFM. Using this strategy, the IDIL technique did not impair valve functions in any patient. Our study demonstrated an improvement in the transvalvular gradient using the IDIL technique with valve function remaining stable throughout the observation period. As our confidence in the IDIL technique has increased, both procedure times and the use of contrast agent have decreased. The potential risks of the IDIL technique are related to the fact that the diagnostic access site has to be increased from 5–6 Fr to 11–12 Fr to perform the valvuloplasty. By applying the IDIL technique, the benefit of reducing the residual transaortic pressure gradient has to be weighed against the risk of vascular complications. However, no vascular complications or detrimental impacts to prosthesis function have been observed. The small number of patients clearly limits the impact of this report. However, our data suggest that the IDIL technique provides an intraprocedural option, optimizing configuration and performance of the DFM prosthesis in complex annular configurations. The IDIL technique should only be performed as a last resort before retrieving the prosthesis. We restrict the indication for this technique to an intraprocedural, unacceptably elevated gradient (>20 mmHg), despite unsuccessful attempts to optimize valve positioning. Native aortic valve asymmetric calcification challenges the implantation and positioning of transcatheter aortic valve prostheses. The IDIL technique-supported implantation is a new technique, allowing the deployment of the DFM under conditions that ensure transvalvular gradient reduction. The 30-day echocardiography follow-up revealed no negative impact of the IDIL technique, indicating good DFM function. Conflict of interest: Hasan Bushnaq is proctor for Direct Flow Medical. The other authors have nothing to disclose. REFERENCES 1 Popma JJ , Adams DH , Reardon MJ , Yakubov SJ , Kleiman NS , Heimansohn D et al. Transcatheter aortic valve replacement using a self-expanding bioprosthesis in patients with severe aortic stenosis at extreme risk for surgery . J Am Coll Cardiol 2014 ; 63 : 1972 – 81 . Google Scholar Crossref Search ADS PubMed WorldCat 2 Leon MB , Smith CR , Mack M , Miller DC , Moses JW , Svensson LG et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery . N Engl J Med 2010 ; 363 : 1597 – 607 . Google Scholar Crossref Search ADS PubMed WorldCat 3 Kodali SK , Williams MR , Smith CR , Svensson LG , Webb JG , Makkar RR et al. Two-year outcomes after transcatheter or surgical aortic-valve replacement . N Engl J Med 2012 ; 366 : 1686 – 95 . Google Scholar Crossref Search ADS PubMed WorldCat 4 Schofer J , Colombo A , Klugmann S , Fajadet J , DeMarco F , Tchetche D et al. Prospective multicenter evaluation of the direct flow medical transcatheter aortic valve . J Am Coll Cardiol 2014 ; 63 : 763 – 8 . Google Scholar Crossref Search ADS PubMed WorldCat 5 Khalique OK , Hahn RT , Gada H , Nazif TM , Vahl TP , George I et al. Quantity and location of aortic valve complex calcification predicts severity and location of paravalvular regurgitation and frequency of post-dilation after balloon-expandable transcatheter aortic valve replacement . JACC Cardiovasc Interv 2014 ; 7 : 885 – 94 . Google Scholar Crossref Search ADS PubMed WorldCat 6 Mihara H , Shibayama K , Berdejo J , Harada K , Itabashi Y , Siegel RJ et al. Impact of device landing zone calcification on paravalvular regurgitation after transcatheter aortic valve replacement: a real-time three-dimensional transesophageal echocardiographic study . J Am Soc Echocardiogr 2015 ; 28 : 404 – 14 . Google Scholar Crossref Search ADS PubMed WorldCat 7 Kische S , D’Ancona G , Agma HU , Gurer H , Ortak J , Elsasser A et al. Transcatheter, inflatable, and fully repositionable aortic valve: preliminary results using a modified implantation technique . Cathet Cardiovasc Intervent 2016 ; 87 : 500 – 7 . Google Scholar Crossref Search ADS WorldCat 8 Kappetein AP , Head SJ , Genereux P , Piazza N , van Mieghem NM , Blackstone EH et al. Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document . J Thorac Cardiovasc Surg 2013 ; 145 : 6 – 23 . Google Scholar Crossref Search ADS PubMed WorldCat 9 Ewe SH , Ng ACT , Schuijf JD , van der Kley F , Colli A , Palmen M et al. Location and severity of aortic valve calcium and implications for aortic regurgitation after transcatheter aortic valve implantation . Am J Cardiol 2011 ; 108 : 1470 – 7 . Google Scholar Crossref Search ADS PubMed WorldCat 10 Krishnaswamy A , Mick S , Kapadia SR. Intraprocedural balloon dilation of the direct flow medical transcatheter aortic valve: First United States experience . Cathet Cardiovasc Intervent 2017 ; 89 : 163 – 7 . Google Scholar Crossref Search ADS WorldCat Author notes † Presented on the 30th Annual Meeting of the European Association for Cardio-Thoracic Surgery, Barcelona, Spain, 1–5 October 2016. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
TI - A new technique to implant a transcatheter inflatable, fully repositionable prosthesis in aortic stenosis with severe asymmetric calcification†
JO - Interactive CardioVascular and Thoracic Surgery
DO - 10.1093/icvts/ivx197
DA - 2017-11-01
UR - https://www.deepdyve.com/lp/oxford-university-press/a-new-technique-to-implant-a-transcatheter-inflatable-fully-aQp1RUl0dC
SP - 679
VL - 25
IS - 5
DP - DeepDyve
ER -