Sohrab Arora

‘Trifecta’ outcomes of robot‐assisted partial nephrectomy in solitary kidney: a Vattikuti Collective Quality Initiative (VCQI) database analysis

To analyse the outcomes of robot‐assisted partial nephrectomy (RAPN) in patients with a solitary kidney in a large multi‐institutional database.

What is the hospital volume threshold to optimize inpatient complication rate after partial nephrectomy

OBJECTIVE To find a cutoff of hospital volume for elective partial nephrectomy (PN) for kidney cancer that can minimize the inpatient morbidity of this procedure. MATERIAL AND METHODS Analyzing the National Inpatient sample, from 2008 to 2011, we selected 8,753 records of adult patients undergoing elective PN for nonmetastatic kidney cancer, representing an estimated 43,178 partial nephrectomies performed in the United States during this period. Of these, 2,187 (estimated 10,848) PNs were performed via the robotic approach. International Classification of Diseases, Ninth Revision, diagnosis and procedure codes were used to define complications. Logistic regression within generalized estimating equation framework, with restricted cubic splines was used to identify the relationship of any inpatient complications and major inpatient complications with annual hospital PN volume, after adjusting for demographic characteristics, insurance status, location, and comorbidities. A similar analysis was done for a subset of patients undergoing robot-assisted PN. RESULTS Overall, rate of any inpatient complication and major inpatient complications was 1,801/8,753 (20.6%) and 839/8,753 (9.6%), respectively. Median annual hospital volume was 27 cases (interquartile range: 11-64). Restricted cubic spline analysis revealed a significant inverse nonlinear association between annual hospital volume and any inpatient complications (P<0.001). The odds of complications decreased with increasing annual hospital volume, with plateauing seen at 35 to 40 cases for both any inpatient complications and major inpatient complications. Analysis on a subset of robot-assisted PN revealed a similar inverse nonlinear relationship, with plateauing at 18 to 20 cases annually. CONCLUSION There is an inverse nonlinear relationship of hospital volume with morbidity of PN, with a plateauing seen at 35 to 40 cases annually overall, and at 18 to 20 cases for robot-assisted PN.

Conversion of Robot-assisted Partial Nephrectomy to Radical Nephrectomy: A Prospective Multi-institutional Study

OBJECTIVE To assess the incidence and factors affecting conversion from robot-assisted partial nephrectomy (RAPN) to radical nephrectomy. METHODS Between November 2014 and February 2017, 501 patients underwent attempted RAPN by 22 surgeons at 14 centers in 9 countries within the Vattikuti Collaborative Quality Initiative database. Patients were permanently logged for RAPN prior to surgery and were analyzed on an intention-to-treat basis. Multivariable logistic regression with backward stepwise selection of variables was done to assess the factors associated with conversion to radical nephrectomy. RESULTS Overall conversion rate was 25 of 501 (5%). Patients converted to radical nephrectomy were older (median age [interquartile range] 66.0 [61.0-74.0] vs 59.0 [50.0-68.0], P = .012), had higher body mass index (BMI) (median 32.8 [24.9-40.9] vs 27.8 [24.6-31.5] kg/m2, P = .031), higher age-adjusted Charlson comorbidity score (median 6.0 [4.0-7.0] vs 4.0 [3.0-5.0], P <.001), higher American Society of Anesthesiologists score (score ≥3; 13/25 (52.0%) vs 130/476 (27.3%), P = .021), Preoperative estimated glomerular filtration rate (P = .141), clinical tumor stage (P = .145), tumor location (P = .140), multifocality (P = .483), and RENAL (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, and anterior/posterior location relative to polar lines) nephrometry score (P = .125) were not significantly different between the groups. On multivariable analysis, independent predictors for conversion were BMI (odds ratio [95% confidence interval]; 1.070 [1.018-1.124]; P = .007) and Charlson score (odds ratio [95% confidence interval]; 1.459 [1.179-1.806]; P = .001). CONCLUSION RAPN was associated with a low rate of conversion. Independent predictors of conversion were BMI and Charlson score. Tumor factors such as clinical stage, location, multifocality, or RENAL score were not associated with increased risk of conversion.

Re: Each procedure matters: threshold for surgeon volume to minimize complications and decrease cost associated with adrenalectomy

With interest, we read the article by Anderson et al on the association of surgeon volume with minimizing complications and decreasing cost associated with adrenalectomy.1 The lack of clarity in the definition of a “high volume” surgeon led the authors to further address this issue. The authors sought to find the threshold annual surgeon volume beyond which there is the least risk of complications. Surgeon volume was used as a continuous, nonlinear variable in logistic regression with restricted cubic splines to predict inpatient complications after adrenalectomy. It was found that “low volume” surgeons were more likely to experience complications, when low volume was defined as <6 cases per year. While this study adds to the growing body of evidence on this subject for other procedures,2,3 a few aspects deserve further consideration. First, for this study the authors used surgeon volume instead of the more commonly used hospital volume. The provider field code in the National Inpatient Sample can refer to either individual physicians or groups of physicians.4,5 It would be interesting to know how the authors accounted for the inconsistent meaning of this variable while calculating surgeon volume. Second, annual hospital volume was calculated as the “total volume for a given surgeon divided by the total number of years that surgeon reported doing at least one adrenalectomy in the patient dataset.” This definition potentially assumes stability, or at least linearity of surgeon volume over the years, which might not be true in real life. As a team leader, the treating physician is one of the strongest spokes in the wheel of safe surgery. Physician volume is an important variable, but surgery is a team effort. An effective team is crucial for communication, early identification of complications, and access to critical related services.6 Surgeon volumes may change when surgeons join teams or hospitals with greater volume referrals for surgery. In this context, hospital volume instead of surgeon volume might be more relevant to the policymaker. The use of hospital volume also will avoid the inconsistent meaning of the provider field code in the National Inpatient Sample. Notwithstanding, this timely study is a step in the right direction and will help the referring physicians as well as the policymakers to make informed decisions.

Testing the external validity of the EORTC randomized trial 30904 comparing overall survival after radical nephrectomy vs nephron-sparing surgery in contemporary North American patients with renal cell cancer

EORTC 30904 reported that for solitary renal mass <=5cm, radical nephrectomy (RN) is associated with higher overall survival compared with nephron sparing surgery (NSS). This trial remains the only available level one evidence on this subject. To test external validity of the trial, patients who met clinical and pathological inclusion criteria of EORTC 30904 within the National Cancer Database (NCDB) were identified. We found that median age (60years in NCDB vs. 62years in trial) and median clinical tumour size (30mm in both) were similar between the cohorts. These two variables are most important determinants of mortality and stage of cancer, respectively, implying that the trial was able to recruit patients virtually representative of those seen in “real-world” practice. Moreover, in NCDB, more patients had clear-cell histology (81.9% vs. 62.9% in trial) and high-grade disease (21.1% vs. 11.2% in trial), implying more aggressive tumors compared to the trial. Arguably, these patients are better served with RN which has a higher probability of completely eradicating the tumor, making the results of the trial even more relevant to practice. Our results indicate that EORTC 30904 cohort was not significantly different from the NCDB cohort in a manner that could influence reported trial outcomes. This article is protected by copyright. All rights reserved.

Bilateral Transvesicoscopic Cross-trigonal Ureteric Reimplantation in Children: Surgical Subtleties and a Prospective Summary

OBJECTIVE To prospectively evaluate the surgical technique and results of bilateral transvesicoscopic cross-trigonal ureteric reimplantation (TVUR) in children with vesicoureteric reflux (VUR) and compare the results and surgical subtleties with the existing literature. MATERIALS AND METHODS From January 2010 to December 2015, children between 2 and 14 years of age with bilateral primary VUR grades II-IV underwent bilateral TVUR at a tertiary referral center in Northern India. The grade of VUR was II in 12 patients, III in 19 patients, and IV in 3 patients. All surgeries were performed by a single surgeon. Success was defined as the absence of VUR on direct radionuclide cystogram at 8 weeks. RESULTS Seventeen patients (34 refluxing ureters) underwent bilateral TVUR during the study period. They included 13 girls and 4 boys. The median age was 4.6 years (range: 2-14 years). Two patients required conversion to open surgery. Resolution of VUR was seen in 16 patients (32 out of 34 ureters). Hydronephrosis resolved on postoperative ultrasonography in all patients with low-grade reflux (lower than grade IV) and all except one patient with grade IV reflux. CONCLUSION TVUR is a feasible method with success rate equal to that of open technique if patient selection is good. Success rate is low in high-grade reflux, and dilated and tortuous ureter. Subtle modifications in the surgical steps can make significant contribution toward learning this minimally invasive technique.

Robotic Buccal Mucosal Graft Ureteroplasty for Complex Ureteral Stricture

OBJECTIVE To demonstrate robot-assisted ureterolysis and buccal mucosal graft (BMG) ureteroplasty for the management of a complex, long recurrent ureteral stricture developing after ureterolysis, and also to demonstrate the use of near-infrared fluorescence (NIRF) imaging and intraoperative ureteroscopy during this procedure. METHODS A 58-year-old man with a history of cabergoline treatment and a cardiac catheterization through the left groin presented with left flank pain and hydronephrosis. A computed tomography scan showed extensive fibrosis around the ureter and a ureteral stricture close to a tortuous left external iliac artery. A computed tomography-guided biopsy showed a benign fibrous tissue around the stricture with no increase in IgG4-expressing plasma cells. A robot-assisted ureterolysis with an omental wrap was performed. One year after the ureterolysis, the patient developed a recurrent ureteral stricture. Retrograde ureterogram showed a long, 6-cm stricture in the upper ureter. For the robotic ureteroplasty, the patient was placed in modified lateral position with port placement similar to the left pyeloplasty. Intraoperative flexible ureteroscopy and NIRF were used to define the distal extent of the stricture. For this, the ureteroscope was advanced until the stricture, and transilluminance of light from the ureteroscope was seen from the robotic camera using Firefly. Ureteral stricture was incised along its length over the ureteroscope. Two BMGs were harvested and sown together to obtain a longer graft. The graft was minimally defatted and brought in the abdomen through one of the ports. The composite graft was then sutured with 4-0 PDS as an onlay graft with the mucosal side facing toward the lumen of the ureter. Ureteroscopy was used to confirm patency, followed by stent placement. NIRF was used to confirm the viability of the ureter and the surrounding tissue. The omental flap was then harvested using a vessel sealer, fixed to the psoas fascia beneath the ureter, and then wrapped over the reconstructed ureter. The omental flap was also tacked to the side of the BMG with a suture to promote blood supply. RESULTS The procedure was uncomplicated with an operative time of 280 minutes, an estimated blood loss of 75 mL, and an uneventful hospital stay. MAG3 Renal scan after 3 and 6 months of surgery showed no recurrence or obstruction. CONCLUSION Despite the limitation of being a single case with only a 6-month follow-up, our report shows that robot-assisted BMG is a safe option for the reconstruction of long upper ureteral strictures. This procedure may be a less morbid alternative to an autotransplant and ileal ureter in these patients. However, outcomes need to be studied in a larger series with a longer follow-up.

Nephropleural Fistula After Percutaneous Nephrolithotomy in a Pediatric Patient: Diagnosis and Management

Nephropleural fistula is a direct and persistent communication between the intrarenal collecting system and the intrathoracic cavity and is a rare complication of supracostal puncture during percutaneous nephrolithotomy. We report a case of a 4-year-old male child who underwent percutaneous removal of a right renal stone. He developed a nephropleural fistula and displacement of double J stent into the pleural cavity. Decompression of the pelvicalyceal system with percutaneous nephrostomy and repositioning of the double J stent allowed for healing of the fistulous connection.

Retroperitoneal vs Transperitoneal Robot-assisted Partial Nephrectomy: Comparison in a Multi-institutional Setting

OBJECTIVES To evaluate retroperitoneal robot-assisted partial nephrectomy (RAPN) against transperitoneal approach in a multi-institutional prospective database, after accounting for potential selection bias that may affect this comparison. PATIENTS AND METHODS Post-hoc analysis of the prospective arm of the Vattikuti Collective Quality Initiative database from 2014 to 2018. Six hundred and ninety consecutive patients underwent RAPN by 22 surgeons at 14 centers in 9 countries. Patients who had surgery at centers not performing retroperitoneal approach (n = 197) were excluded. Inverse probability of treatment weighting was done to account for potential selection bias by adjusting for age, gender, body mass index, comorbidities, side of surgery, location/size/complexity of tumor, renal function, American Society of Anesthesiologists score, and year of surgery. Operative and perioperative outcomes were compared between weighted transperitoneal and retroperitoneal cohorts. RESULTS Ninety-nine patients underwent retroperitoneal RAPN; 394 underwent transperitoneal RAPN. Hospital stay in days-median 3.0 (Interquartile range [IQR] 2.0-4.0) transperitoneal vs 1.0 (1.0-3.0) retroperitoneal; P < .001, and blood loss in mL-125 (50-250) transperitoneal vs 100 (50-150) retroperitoneal; P = .007-were lower in the retroperitoneal group. There were no differences in operative time (P = .6), warm ischemia time (P = .6), intraoperative complications (P = .99), conversion to radical nephrectomy (P = .6), postoperative major complications (P = .6), positive surgical margins (P = .95), or drop in estimated glomerular filtration rate (P = .7). CONCLUSION In a multi-institutional setting, both retroperitoneal and transperitoneal approach to RAPN have comparable operative and perioperative outcomes, except for shorter hospital stay with the retroperitoneal approach.

Robotic Kidney Transplantation

Kidney transplant is the treatment of choice for end-stage renal disease. Vattikuti Urology Institute (VUI) technique of robot-assisted renal transplant not only offers all the benefits of minimally invasive surgery to the patient, but also has a trend towards lower complication rates. The technique is associated with reduced surgical site infections and is especially useful in obese transplant recipients. This chapter reviews the development of robot-assisted renal transplant and its outcomes as compared to open kidney transplant, with a focus on complications and their prevention.