TY - JOUR
AU1 - Roy, Sreeja Biswas
AU2 - Haworth, Cassandra
AU3 - Ipsen, Taylor
AU4 - Kang, Paul
AU5 - Hill, David
AU6 - Do, Annie
AU7 - Kuo, Elbert
AB - Abstract OBJECTIVES Diaphragmatic paralysis, a known cause of dyspnoea, can drastically reduce breathing efficiency, diminishing quality of life. We report our 3.5-year experience with 22 consecutive patients who underwent transabdominal, robot-assisted diaphragmatic plication for diaphragmatic paralysis. METHODS We retrospectively reviewed 22 consecutive patients who underwent this procedure by a single surgeon from 5 September 2012 to 12 May 2016. The primary outcome measure was change in dyspnoea severity, which was measured with the 5-point Medical Research Council dyspnoea scale (a score of 5 indicates breathlessness so severe, the individual is homebound). RESULTS Of the 22 patients who underwent robotic diaphragmatic plication, 17 (77.3%) patients were male. Median body mass index was 30 kg/m2 (range 24.2–42.17 kg/m2). Most plications (13 of 22, 59.1%) were left sided; one (4.6%) was bilateral. Median operating time was 161 min (range 107–293 min), but this time was higher for the first 3 procedures (255 min, range 239–293 min). Median length of stay was 2 days, and median time to chest tube removal was 1 day. At follow-up, 20 of the 22 (91%) patients reported improved breathing and 2 reported no change. No patient reported worsened dyspnoea. The median Medical Research Council score changed from 4.0 preoperatively to 2.0 postoperatively (P = 0.001). CONCLUSIONS Transabdominal robotic diaphragmatic plication involves small incisions but improves surgical dexterity. Surgical times are reasonable, and this surgical technique can be adopted with a quick but steep learning curve. Early results show good functional outcomes. Diaphragmatic paralysis, Transabdominal robotic plication INTRODUCTION Diaphragmatic paralysis is a known cause of dyspnoea that can drastically reduce forced vital capacity (FVC) and forced expiratory volume (FEV1), often resulting in upright sleeping, inability to exercise and decreased quality of life [1]. It may be idiopathic or it may result from a variety of known causes (e.g. trauma, spinal cord injury and phrenic nerve injury after cardiac surgery) [1]. The paradoxical motion of a paralyzed diaphragm contributes to dyspnoea, atelectasis, frequent recurrent pneumonia and contralateral mediastinal shift [1]. Diaphragmatic paralysis can be diagnosed on radiography, computed tomography or magnetic resonance imaging and confirmed with a sniff test showing an elevated diaphragm with paradoxical motion. Surgical intervention is only indicated for symptomatic patients, and the preferred surgical technique is diaphragmatic plication. Several approaches and surgical techniques may be used for plication of the diaphragm. Open transthoracic plication is the traditional method [2, 3], and although it is still used today [4, 5], more surgeons are moving towards less invasive approaches such as thoracoscopy or laparoscopy. These methods offer benefits such as decreased postoperative pain, shorter length of stay (LOS) in the hospital and swifter recovery [6–8]. Robot-assisted surgery offers all the benefits of a minimally invasive approach while simultaneously providing the surgeon with the surgical dexterity associated with an open approach [9, 10]. Many authors have reported outcomes of patients who have undergone open, thoracoscopic and laparoscopic diaphragmatic plication. However, to date, there has been just 1 report of transabdominal robot-assisted diaphragmatic plication [10]. Herein, we report the outcomes of our 3.5-year study of 22 patients who underwent transabdominal robot-assisted diaphragmatic plication by a single surgeon. We also provide a detailed description of our operative technique. MATERIALS AND METHODS Patient population A retrospective, single-centre, chart-based review was conducted after obtaining approval from the Institutional Review Board at St. Joseph’s Hospital and Medical Center in Phoenix, AZ, USA. Between 5 September 2012 and 12 May 2016, 22 consecutive adult patients underwent robot-assisted diaphragmatic plication at Norton Thoracic Institute in Phoenix, AZ, USA, for diaphragmatic paralysis. All 22 procedures were performed by the same surgeon. Outcome analysis Patient characteristics studied included age, gender, body mass index, smoking status and cause of paralysis. Total time in the operating room, operative time, estimated blood loss, LOS, time to chest tube removal, complications, pre- and postoperative pulmonary function tests and pre- and postoperative radiological measurements of lung volume were recorded. A follow-up telephone survey of all 22 patients was conducted using the Medical Research Council (MRC) dyspnoea scale (see Supplementary Material). The MRC dyspnoea scale is a 5-point scale, with 5 describing the worst dyspnoea (i.e. breathlessness so severe, the individual remains homebound). Pre- and postoperative dyspnoea scale scores after robot-assisted diaphragmatic plication via an abdominal approach were recorded. Radiographic studies A single radiologist carried out cranial–caudal lung measurements on pre- and postoperative chest radiographs. All measurements were computed in the midclavicular line from the anteroposterior view. A ratio between the affected lung and the un-affected lung (i.e. affected/normal lung ratio) was computed, and each patient’s pre- and postoperative lung ratios were compared. Statistical analysis Demographics and clinical characteristics of patients who observed changes in MRC scores of <3 and ≥3 were assessed using medians, interquartile range (IQR) for continuous variables and frequencies and proportions for categorical variables. Because of the small sample size, all continuous variables were assumed to be non-normally distributed. All categorical variables showed expected counts within the 2 × 2 contingency table of <5. Thus, the non-parametric Wilcoxon rank-sum test was used to compare continuous variables, whereas Fisher’s exact test was used to compare the categorical variables between the 2 samples. All P-values were 2-sided, and statistical significance was set at P <0.05. All statistical analyses were conducted using STATA version 14 (StataCorp LP, College Station, TX, USA). Operative technique Patient positioning and port placement All patients undergo general anaesthesia and are placed supine on the operating table, with both arms tucked at the sides and a rolled blanket under the paralyzed side to create a slight bump. A Foley catheter, intravenous line, orogastric tube and arterial line are placed. A Bair Hugger warming unit (3 M, St. Paul, MN, USA) may be used to maintain the core body temperature during the procedure. The patient should be prepped and draped from the chest to the pelvis. We prefer single-lung isolation with a double-lumen tube, but a single-lumen endotracheal tube with a bronchial blocker can also be used. If lung isolation is not possible, periodic apnoea is acceptable. We are careful during patient prep to leave the room for placement of a pigtail catheter on the affected side to relieve the capnothorax. The location on the lateral chest wall where the pigtail catheter will be placed should be prepared and sterilized. After a surgical timeout to verify the patient’s identity, surgical site and procedure, a 5-mm incision is made slightly off the midline on the paralyzed side of the abdominal cavity, halfway between the xiphoid process and the umbilicus. Pneumoperitoneum (15 mmHg) is established. A 5-mm optical trocar is advanced to allow for visualization of the abdominal cavity before a 5-mm 30° laparoscope is introduced. Two 5-mm robotic left- and right-handed operative ports are then placed 10 cm from the initial port, in the same plane. One 8-mm robotic port is also placed in the same plane, contralateral to the paralyzed side, to allow for a robotic dual blade retractor. A bariatric trocar is most suitable for this port, particularly in the case of overweight patients. This extra-long trocar helps avoid collision with the patient’s shoulder and with the second robotic arm. The camera port is then upsized to an 8-mm robotic camera port, and an 8-mm AirSeal Access Port (Techs2Life, Athens, Greece) is triangulated inferiorly between the camera port and a 5-mm port on the contralateral side (Fig. 1). The patient is then moved to a 30° reverse Trendelenburg position to allow the bowels and spleen to fall away from the diaphragm and out of the field of visualization. A Harmonic scalpel (Harmonic Synergy, Ethicon, Somerville, NJ, USA) is used to take down the falciform ligament, which clears a path across the midline for the robotic instruments. The robot is docked and an 8-mm 0° robotic camera is inserted. A 5-mm hook cautery is inserted on the affected side, and a 5-mm needle driver is inserted on the contralateral side. A dual-bladed 8-mm fan retractor is placed in the last robotic arm. Finally, 2 rolled gauze sponges are placed through the 8-mm AirSeal Access Port to use on the fan retractor and distribute retraction pressure. Figure 1: View largeDownload slide Five ports are placed to facilitate robotic plication of the diaphragm. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 1: View largeDownload slide Five ports are placed to facilitate robotic plication of the diaphragm. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Release of the paralyzed diaphragm tension The paralyzed diaphragm will be retracted very high in the chest due to the pneumoperitoneum. A paralyzed diaphragm is usually extremely thin, and lung parenchyma is often visible through the diaphragm. At this point, the anaesthesiologist stops ventilating the lung on the affected side. If single-lung ventilation is not possible, a short period of apnoea is acceptable. Because the diaphragm is retracted, the right-handed robotic trocar often must be advanced into the field for the hook cautery to reach it. The hook cautery is used to make a small hole at the centre of the paralyzed diaphragm (Fig. 2), creating a capnothorax and that equalizes the pressures in the chest and abdomen. The anaesthesiologist should be notified before the capnothorax is created, as the venous return to the heart can temporarily decrease as a result. Once chest and abdominal pressures are equalized, the paralyzed diaphragm becomes loose and floppy, and the right-handed robotic trocar can be returned to its original position. Figure 2: View largeDownload slide Hook cautery is used to make a small hole in the centre of the paralyzed diaphragm, creating a capnothorax that equalizes the pressure in the chest and abdomen. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 2: View largeDownload slide Hook cautery is used to make a small hole in the centre of the paralyzed diaphragm, creating a capnothorax that equalizes the pressure in the chest and abdomen. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Plication of the diaphragm The rolled gauze sponges held by the third robotic arm with the dual-blade retractor are used to help retract the abdominal viscera enough to ensure adequate space for plication. One end of a double-armed 0 suture (Ethibond, Ethicon, Somerville, NJ, USA), which is preloaded with a cotton pledget (measuring 3/8″ × 3/16″ × 1/16″), is introduced through the AirSeal Access Port. Plication is initiated medially and proceeds laterally along the diaphragm. We start at the posterior side of the diaphragm and make multiple suture passes, working towards the anterior diaphragm. It is critical to start the plication posterior to the lateral branch of the inferior phrenic artery (Fig. 3) to ensure that the posterior aspect of the diaphragm is included in the plication. In our experience, beginning the plication from the posterior aspect of the diaphragm and moving anteriorly also helped to avoid entanglement of the sutures. Figure 3: View largeDownload slide Plication proceeds from the lateral branch of the inferior phrenic artery to the anterior portion of the diaphragm. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 3: View largeDownload slide Plication proceeds from the lateral branch of the inferior phrenic artery to the anterior portion of the diaphragm. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. For the initial suture pass, the assistant may need to pull-out the diaphragm. Once the first suture is pulled through, the other end of the double-armed suture is introduced and a second suture is made parallel to the first. Entanglement of the sutures is also prevented by Kelly forceps, which pull the first suture up to the level of the trocar while the next needle is introduced. After the second stitch is pulled through, another cotton pledget is pushed down to the diaphragm with a needle driver. A 5-mm Ti-Knot device (LSI Solutions, Victor, NY, USA) is used to tightly secure the sutures. The surgeon should maintain excellent communication with the assistant at the table to know how much tension the assistant is exerting when putting down the Ti-Knot device. The assistant may use Kelly forceps to hold the free end of the suture preventing slippage. This process is repeated until plication of the diaphragm is complete. As the surgeon progresses in a lateral direction, each new suture is started more posteriorly than the previous to ensure a tight plication. The hole in the diaphragm, which was created by the hook cautery at the onset of the procedure, is incorporated into the suture during plication. Sutures are spaced approximately 2 cm apart (Fig. 4). In total, 8 sutures are usually required to complete adequate plication of the diaphragm (Fig. 5). Capnothorax can be relieved by placing a 14-Fr pigtail catheter in the affected side of the chest using the Seldinger technique. The suction pressure of the chest tube is set at 20 cmH2O. Inadvertent lung injury can be avoided by pausing ventilation on the affected side as the pigtail catheter is inserted. After the pigtail is placed, the rolled gauze should be removed from the operative field and a vital capacity breath should be given to allow for full expansion of the isolated lung and evacuation of the capnothorax. The robot is then un-docked and the trocars are removed. Figure 4: View largeDownload slide Double-armed sutures are passed laterally and spaced approximately 2 cm apart. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 4: View largeDownload slide Double-armed sutures are passed laterally and spaced approximately 2 cm apart. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 5: View largeDownload slide (A) Approximately 8 sutures are required to complete diaphragmatic plication. (B) Intraoperative photograph shows placement of pledgeted sutures in the diaphragm. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 5: View largeDownload slide (A) Approximately 8 sutures are required to complete diaphragmatic plication. (B) Intraoperative photograph shows placement of pledgeted sutures in the diaphragm. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. RESULTS Baseline demographics and preoperative findings The median patient age was 61 (range 33–80) years. Of the 22 patients, 17 (77.3%) patients were male. Median body mass index was 30 kg/m2 (IQR 26.9–31.6). Ten (45.5%) patients had a positive history of smoking. Paralysis was left sided in 13 of the 22 (59.1%) patients, while 1 (4.6%) patient experienced bilateral paralysis. Aetiology of paralysis was traumatic in 5 (22.7%) patients, neurological in 4 (18.2%) patients, iatrogenic following open cardiac surgery in 4 (18.2%) patients and non-traumatic or unknown in 9 (41.0%) patients. Patient demographics are summarized in Table 1. Table 1: Demographics and clinical characteristics Variables  Overall population (N = 22)  MRC difference of <3 (n = 12)  MRC difference ≥3 (n = 10)  P-valuea  Median age (IQR), years  61 (53–67)  64 (56.5–69.5)  58.5 (52–65)  0.24  Male gender, n (%)  17 (77.3)  8 (66.7)  9 (90.0)  0.32  Smoking history, n (%)  10 (45.5)  4 (33.3)  6 (60.0)  0.27  Median BMI (IQR), kg/m2  30 (26.9–31.6)  28.9 (26.7–31.3)  31.1 (29.4–32.6)  0.35  Left-sided plication, n (%)  13 (59.1)  7 (58.3)  4 (40.0)  1.0  Median duration of surgery (IQR), min  161 (125–174)  153.5 (128–180)  164 (125–171)  0.64  Median estimated blood loss (IQR), ml  50 (25–50)  50 (25–62.5)  40 (25–50)  0.57  Median LOS (IQR), days  3 (2, 4)  3 (2–4)  2.5 (2–3)  0.39  Median total chest tube output (IQR), ml  119.5 (50–411)  135.5 (55.5)  90 (50–510)  0.86  Median preoperative FEV1% predicted (IQR)  57 (48–64)  57 (47.5–64.5)  57 (49–62)  0.91  Median preoperative TLC % predicted (IQR)  81 (70–88)  81.5 (68.5–88)  77 (74–91)  0.85  Variables  Overall population (N = 22)  MRC difference of <3 (n = 12)  MRC difference ≥3 (n = 10)  P-valuea  Median age (IQR), years  61 (53–67)  64 (56.5–69.5)  58.5 (52–65)  0.24  Male gender, n (%)  17 (77.3)  8 (66.7)  9 (90.0)  0.32  Smoking history, n (%)  10 (45.5)  4 (33.3)  6 (60.0)  0.27  Median BMI (IQR), kg/m2  30 (26.9–31.6)  28.9 (26.7–31.3)  31.1 (29.4–32.6)  0.35  Left-sided plication, n (%)  13 (59.1)  7 (58.3)  4 (40.0)  1.0  Median duration of surgery (IQR), min  161 (125–174)  153.5 (128–180)  164 (125–171)  0.64  Median estimated blood loss (IQR), ml  50 (25–50)  50 (25–62.5)  40 (25–50)  0.57  Median LOS (IQR), days  3 (2, 4)  3 (2–4)  2.5 (2–3)  0.39  Median total chest tube output (IQR), ml  119.5 (50–411)  135.5 (55.5)  90 (50–510)  0.86  Median preoperative FEV1% predicted (IQR)  57 (48–64)  57 (47.5–64.5)  57 (49–62)  0.91  Median preoperative TLC % predicted (IQR)  81 (70–88)  81.5 (68.5–88)  77 (74–91)  0.85  a P-values are calculated using the Wilcoxon rank-sum test for continuous variables and Fisher’s exact for categorical variables. BMI: body mass index; FEV1: forced expiratory volume in 1 s; IQR: interquartile range; LOS: length of stay; MRC: Medical Research Council; TLC: total lung capacity. Pulmonary function tests All 22 patients underwent pulmonary function testing (PFT) as part of their initial workup for diaphragmatic paralysis. The median preoperative FEV1 was 57% (IQR 48–64%) of predicted. The median preoperative FVC was 57% (IQR 50–60%) of predicted. The median diffusing capacity of lung for carbon monoxide was 65% (IQR 48–83%) of predicted. Chest radiographs The pre- and postoperative chest radiographs in 20 of 22 patients were available for ratio comparison (affected/normal lung). Two patients were excluded from the radiographic analysis, as preoperative images were missing for 1 patient and another underwent bilateral diaphragmatic plication. Seventeen of the 20 patients had a 15% or greater change between pre- and postoperative affected/normal lung ratios. All patients saw an improvement in bilateral lung symmetry, ranging from 9% to 68% on their postoperative chest radiographs. Figure 6 compares side-by-side preoperative (Fig. 6A) and postoperative chest radiographs (Fig. 6B and C) of a patient who underwent successful diaphragmatic plication. Figure 6: View largeDownload slide (A) Preoperative erect chest radiograph shows markedly elevated left hemidiaphragm. (B) Immediate postoperative chest radiograph demonstrates drastic improvement. (C) Chest radiograph 3 months after surgery shows persistent improvement. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Figure 6: View largeDownload slide (A) Preoperative erect chest radiograph shows markedly elevated left hemidiaphragm. (B) Immediate postoperative chest radiograph demonstrates drastic improvement. (C) Chest radiograph 3 months after surgery shows persistent improvement. Used with permission from Norton Thoracic Institute, Phoenix, AZ, USA. Medical Research Council dyspnoea score The median preoperative MRC dyspnoea score was 4 (IQR 3.25–4.75). The median follow-up time was 95 weeks (IQR 69–143; range 35–227 weeks). The median postoperative dyspnoea score was 2.0 (IQR 0.25–3.75). The median time to postoperative breathing improvement was 1 week (IQR 1–4.5 weeks). Surgery and hospital course Median operating time was 161 min (IQR 128.25–138; range 107–293 min). Because of the steep learning curve associated with this procedure, the median operating time for the first 3 patients was higher at 255 min. This number dropped dramatically for the next 19 patients, to a median of 149 min (range 107–207 min). The median estimated blood loss during surgery was 50 ml (IQR 25–50 ml). Median time to chest tube removal was 1 day (IQR 1–2 days). Median total LOS was 3 days (IQR 2–3 days). DISCUSSION In 1923, Morison [3] described a series of 9 patients found to have elevation of the diaphragm, which was repaired through an open thoracotomy. For decades, this approach was the mainstay of surgical treatment for diaphragmatic plication, with both short- and long-term benefits reported by many groups [2, 4, 5, 11, 12]. As surgical instrumentation and visualization evolved, minimally invasive approaches were developed that were associated with less postoperative pain, quicker recovery and shorter LOS. Both thoracoscopic [8, 13–16] and laparoscopic approaches [6, 7, 17] have been described; however, the technically challenging nature of these techniques has limited widespread adoption—particularly for the laparoscopic approach. Video-assisted thoracoscopy thus remains the more popular approach to diaphragmatic repair, with long-term follow-up data attesting to its efficacy as comparable to that of open thoracotomy [11]. In 2004, Hüttl et al. [7] described their experience with 3 patients who underwent laparoscopic abdominal plication for phrenic nerve injury after open-heart surgery. All 3 patients remained free of recurrence at 6 years’ follow-up. Since then, other authors have published their experience with the abdominal approach [6, 10, 17]. In 2010, Groth et al. [6] reported results from a larger series of 25 patients who underwent laparoscopic plication of the diaphragm. They assessed pre- and postoperative levels of dyspnoea using PFTs and the St. George’s Respiratory Questionnaire. The patients in their study experienced significant improvement in both St. George’s Respiratory Questionnaire scores and PFTs at 1-month and 1-year follow-up [6]. Similar to Hüttl et al. [7], Groth et al. [6] reported adequate space in the surgical field and enhanced visualization of the anatomy with a median length of stay of 4 days. Podgaetz et al. [17] later reported a preference for the laparoscopic approach over the more common thoracoscopic approach, citing its increased workspace, better visualization, avoidance of selective lung ventilation and reduced postoperative intercostal nerve pain as attractive benefits of the laparoscopic approach. A small percentage (4%) of patients in the study by Groth et al. [6] underwent conversion from minimally invasive surgery to open thoracotomy. Such conversions were required due to intraoperative complications, frequently in morbidly obese patients. Morbid obesity may be a contraindication to minimally invasive plication techniques, and we encourage obese patients to lose weight before this surgery, if needed, and to make an effort to adopt healthier lifestyle changes. However, in 2012, Kwak et al. [9] reported what appears to be the first successful robotic thoracoscopic plication case on a morbidly obese young man who was otherwise healthy (body mass index = 38 kg/m2). They did not experience any adverse outcomes with this patient. In 2013, Ahn et al. [18] described a patient who underwent robot-assisted thoracoscopic surgery for diaphragmatic plication. They supplemented their thoracoscopic approach with laparoscopy to compensate for 2 major shortcomings of robotic surgery: (i) the absence of tactile sensation and (ii) the absence of force feedback. Both of these are associated with intra-abdominal organ injury. With their modified approach, Ahn et al. [18] reported enhanced dexterity in the operative field and magnified 3D vision as benefits of robotic surgery. Zwischenberger etal. [10] recently described the outcomes of 3 patients who also underwent laparoscopic robotic diaphragmatic plication. All 3 patients in their series had improved FVC and FEV1 and resumed normal activity after 2 weeks. Our approach and technique is very similar to that reported by Zwischenberger etal. [10] but differs in 4 main ways. First, in our patients, we only used a rolled towel to provide a slight bump, as opposed to the 45° bump reported by Zwischenberger et al. Second, we used an 8-mm 0° scope (instead of a 30° scope), two 5-mm working ports (instead of 8-mm working ports) and added an additional 8-mm assist AirSeal port. We used the fourth robotic arm to retract the abdominal viscera and the liver. In our experience, this additional retractor port has been helpful in clearing the operative field of anatomy that would otherwise obstruct visibility and dexterity (e.g. the stomach, the small intestine and the liver). The third difference between our approach and the approach described by Zwischenberger et al. is our preference for single-lung ventilation whenever possible; this helped us ensure that the lung was decompressed so that we could avoid injuring the lung during our plication sutures. Fourth, we used individual felt pledgets instead of a felt strip. We found that the individual pledgets were less awkward to handle and were less likely to become entangled. Use of the robot provided improved surgical dexterity and better visualization without increasing operative room times. The results of our single-surgeon experience show that patients had excellent clinical outcomes after median follow-up of 1.8 years (i.e. 95 weeks) after transabdominal robot-assisted diaphragmatic plication. Damage to the phrenic nerve, which often causes diaphragmatic paralysis, can sometimes resolve on its own [2]. Therefore, we wait at least 6 months from the time of diagnosis before considering surgical intervention. In our series, 20 of 22 patients had excellent clinical outcomes postoperatively. Patients improved from a preoperative MRC score of 4 to an MRC score of 2 postoperatively. Ten of the 22 patients were not troubled by breathlessness, except on strenuous exercise after the operation. In addition, most patients showed improved symmetry between the affected lung and the normal lung. Our patients’ median LOS was 3 days. No patient experienced pleural effusion. When we compared patients who had an MRC improvement of more than 3 points on the scale to the rest of the patients, we did not find any significant predictors, other than a lower average LOS for those patients. Regarding the 2 patients who did not experience symptom improvement after surgery, 1 patient showed a slight improvement in MRC score in the immediate postoperative period but regressed to the preoperative MRC score over the following year. Postoperative PFTs for this patient showed improvement in FEV1 and FVC after surgery, but the gradual progression of this patient’s intrinsic lung disease was reflected in a decrease in diffusing capacity of lung for carbon monoxide. The other patient, whose dyspnoea did not resolve after surgery, was 80 years old and had a preoperative diffusing capacity of lung for carbon monoxide of just 26%. Postoperatively, this patient went into atrial fibrillation with rapid ventricular response, leading to acute respiratory distress that required intubation and mechanical ventilation for 4 days. His total LOS was 12 days, and his chest tube was removed on the 8th postoperative day. Our limited experience with elderly patients who have poor intrinsic lung function suggests that surgery for diaphragmatic plication might be associated with higher risks in the immediate postoperative period. Widespread adoption of thoracoscopic and laparoscopic approaches to diaphragmatic plication has been hindered by the technical skill set required to perform these operations safely. Our data show that transabdominal robot-assisted diaphragmatic plication is associated with a steep and rapid learning curve—the mean operating room time for this procedure dropped by approximately 100 min after the first 3 cases. The laparoscopic approach may offer better visualization and greater workspace than the thoracoscopic approach, as it allows for retraction of the abdominal organs. All incisions are port sized, which avoids complications associated with a mini- or full thoracotomy incision. In the laparoscopic approach, care must be taken when making the first nick on the diaphragm, and the anaesthesiologist must be informed to avoid hypotension due to decreased venous return to the heart. Care must also be taken not to injure the ipsilateral lung. We did not experience any complications during this critical step of the operation. The widespread adoption of the laparoscopic approach instead of the thoracoscopic approach for diaphragmatic plication (and the adoption of robotic over the conventional minimally invasive approach) is largely a matter of surgeon preference and institutional practices. Further randomized studies are warranted to determine whether the laparoscopic approach indeed offers both short- and long-term benefits over the thoracoscopic approach. Over the course of our experience with 22 patients, we compiled a list of tips and tricks that facilitated the procedure (Table 2). Table 2: Surgical tips and tricks for transabdominal robot-assisted diaphragmatic plication Operative stage  Tips and tricks  Patient positioning and port placement  Prep lateral chest in anticipation of pigtail placement  Decompress the stomach with an orogastric tube before starting the procedure  Use a bariatric 8-mm trocar in third robotic arm for dual fan blade retractor  Use 8-mm AirSeal Access Port (Techs2Life, Athens, Greece) to maintain pneumoperitoneum  Place patient in 30° reverse Trendelenburg position  Releasing the paralyzed diaphragm tension  Advance right-handed robotic trocar farther into field to make diaphragm opening, then pull trocar back to its operative position.  Plication of the diaphragm  Plicate the diaphragm from posterior aspect and advance towards anterior aspect  Pull the first suture to the level of the trocar and hold it taut to avoid entanglement  Push the pledget down before using the Ti-Knot so the pledget does not get caught in the device  Operative stage  Tips and tricks  Patient positioning and port placement  Prep lateral chest in anticipation of pigtail placement  Decompress the stomach with an orogastric tube before starting the procedure  Use a bariatric 8-mm trocar in third robotic arm for dual fan blade retractor  Use 8-mm AirSeal Access Port (Techs2Life, Athens, Greece) to maintain pneumoperitoneum  Place patient in 30° reverse Trendelenburg position  Releasing the paralyzed diaphragm tension  Advance right-handed robotic trocar farther into field to make diaphragm opening, then pull trocar back to its operative position.  Plication of the diaphragm  Plicate the diaphragm from posterior aspect and advance towards anterior aspect  Pull the first suture to the level of the trocar and hold it taut to avoid entanglement  Push the pledget down before using the Ti-Knot so the pledget does not get caught in the device  Limitations Our study has several limitations. Like any single-surgeon, single-arm retrospective study, our data are prone to selection bias. Postoperative PFT data were only available for 6 of the 22 patients. This is because, in our clinical practice, we see patients only once or twice postoperatively, at which point they transition to following up with their pulmonologists. If they are doing well, we do not carry out repeat PFTs after the operation. The decision to repeat these tests is made at the discretion of the referring pulmonologist. Our data on patient clinical outcomes were conducted via telephone survey; patients’ perception of their breathing before and after the operation was subjective in nature. Furthermore, each operation was conducted on the da Vinci Xi system (Intuitive Surgical, Sunnyvale, CA, USA); newer platforms may offer technical advantages that were not available during this study period. The small sample size of our study population limited a meaningful regression analysis to ascertain potential risk factors in the patients’ history, which could predict worse outcomes postoperatively. Despite these limitations, our series demonstrates that transabdominal robotic diaphragmatic plication can be performed with excellent clinical outcomes, a short LOS and a rapid learning curve. CONCLUSION Robot-assisted laparoscopic diaphragmatic plication is a viable option for surgical treatment of diaphragmatic paralysis. Robot-assisted laparoscopic diaphragmatic plication is associated with a short learning curve and good clinical outcomes. SUPPLEMENTARY MATERIAL Supplementary material is available at EJCTS online. ACKNOWLEDGEMENTS The authors wish to thank Ross M. Bremner for his review and insightful feedback on this article as well as Timothy Fey for study supervision. 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TI - Transabdominal robot-assisted diaphragmatic plication: a 3.5-year experience
JF - European Journal of Cardio-Thoracic Surgery
DO - 10.1093/ejcts/ezx255
DA - 2017-07-25
UR - https://www.deepdyve.com/lp/oxford-university-press/transabdominal-robot-assisted-diaphragmatic-plication-a-3-5-year-aveElpJdh2
SP - 247
EP - 253
VL - 53
IS - 1
DP - DeepDyve
ER -