Brian M. Benway

Robot assisted partial nephrectomy versus laparoscopic partial nephrectomy for renal tumors: a multi-institutional analysis of perioperative outcomes.

PURPOSE Robot assisted partial nephrectomy is rapidly emerging as an alternative to laparoscopic partial nephrectomy for the treatment of renal malignancy. We present the largest multi-institution comparison of the 2 approaches to date, describing outcomes from 3 experienced minimally invasive surgeons. MATERIALS AND METHODS We performed a retrospective chart review, evaluating 118 consecutive laparoscopic partial nephrectomies and 129 consecutive robot assisted partial nephrectomies performed between 2004 and 2008 by 3 experienced minimally invasive surgeons at 3 academic centers. Perioperative data were recorded along with clinical and pathological outcomes. RESULTS The robot assisted and laparoscopic partial nephrectomy groups were equivalent in terms of age, gender, body mass index, American Society of Anesthesiologists classification (2.3 vs 2.4) and radiographic tumor size (2.9 vs 2.6 cm), respectively. Comparison of operative data revealed no significant differences in terms of overall operative time (189 vs 174 minutes), collecting system entry (47% vs 54%), pathological tumor size (2.8 vs 2.5 cm) and positive margin rate (3.9% vs 1%) for robot assisted and laparoscopic partial nephrectomy, respectively. Intraoperative blood loss was less for robot assisted vs laparoscopic partial nephrectomy (155 vs 196 ml, p = 0.03) as was length of hospital stay (2.4 vs 2.7 days, p <0.0001). Warm ischemia times were significantly shorter in the robot assisted partial nephrectomy series (19.7 vs 28.4 minutes, p <0.0001). Subset analysis based on complexity revealed that tumor complexity had no effect on operative time or estimated blood loss for robot assisted partial nephrectomy, although complexity did affect these factors for laparoscopic partial nephrectomy. In addition, for simple and complex tumors robot assisted partial nephrectomy provided significantly shorter warm ischemic time than laparoscopic partial nephrectomy (15.3 vs 25.2 minutes for simple, p <0.0001; 25.9 vs 36.7 minutes for complex, p = 0.0002). There were no intraoperative complications during robot assisted partial nephrectomy vs 1 complication during laparoscopic partial nephrectomy. Postoperative complication rates were similar for robot assisted and laparoscopic partial nephrectomy (8.6% vs 10.2%). CONCLUSIONS Robot assisted partial nephrectomy is a safe and viable alternative to laparoscopic partial nephrectomy, providing equivalent early oncological outcomes and comparable morbidity to a traditional laparoscopic approach. Moreover robot assisted partial nephrectomy appears to offer the advantages of decreased hospital stay as well as significantly less intraoperative blood loss and shorter warm ischemia time, the latter of which may help to provide maximal preservation of renal reserve. In addition, operative parameters for robot assisted partial nephrectomy appear to be less affected by tumor complexity compared to laparoscopic partial nephrectomy. Interestingly while the advantages of robotic surgery have historically been believed to aid laparoscopic naïve surgeons, these data indicate that robot assisted partial nephrectomy may also benefit experienced laparoscopic surgeons.

Robotic Partial Nephrectomy with Sliding-Clip Renorrhaphy: Technique and Outcomes

BACKGROUND Robotic partial nephrectomy (RPN) is emerging as an alternative to traditional laparoscopic partial nephrectomy (LPN). Despite the potential advantages of the robotic approach, renorrhaphy remains a challenging portion of the procedure. OBJECTIVE To present our technique and outcomes for RPN, including sliding-clip renorrhaphy. DESIGN, SETTING, AND PARTICIPANTS Between 2007 and 2008, 50 patients underwent RPN performed by a single attending surgeon. SURGICAL PROCEDURE In this paper, we describe our technique for RPN, including a sliding-clip renorrhaphy, which is distinguished by the use of Weck Hem-O-Lock clips that are slid into place under complete control of the surgeon seated at the console and secured with a LapraTy clip. For the first 13 procedures, traditional tied-suture or assistant-placed clip closures were performed; sliding-clip renorrhaphy was performed in the remaining 37 cases. RESULTS AND LIMITATIONS Mean tumor size was 2.5 cm. Mean operative time was 145.3 min, and mean overall warm ischemia time was 17.8 min. Mean estimated blood loss was 140.3 ml. The learning curve for overall operative time was 19 cases; the learning curve for portions of the case performed under warm ischemia (including tumor resection and renorrhaphy) was 26 cases. The introduction of a sliding-clip renorrhaphy produced significant reductions in overall operative time and warm ischemia time, while blood loss and hospital stay remained stable over our experience. Limitations of RPN include cost and increased reliance on the bedside assistant. CONCLUSIONS Sliding-clip renorrhaphy provides an efficient and effective repair that is under nearly complete control of the surgeon. This technique appears to contribute to significantly shorter overall operative times and, perhaps most critically, to shorter warm ischemia times. The learning curve for RPN using this technique appears to be foreshortened compared with LPN.

Robot-Assisted Partial Nephrectomy: An International Experience

BACKGROUND Robot-assisted partial nephrectomy (RAPN) is emerging as a viable approach for nephron-sparing surgery (NSS), though many reports to date have been limited by evaluation of a relatively small number of patients. OBJECTIVE We present the largest multicenter RAPN experience to date, culling data from four high-volume centers, with focus upon functional and oncologic outcomes. DESIGN, SETTING, AND PARTICIPANTS A retrospective chart review was performed for 183 patients who underwent RAPN at four centers between 2006 and 2008. SURGICAL PROCEDURE RAPN was performed using methods outlined in the supplemental video material. Though operative technique was similar across all institutions, there were minor variations in trocar placement and hilar control. MEASUREMENTS Perioperative parameters, including operative time, warm ischemic time, blood loss, and perioperative complications were recorded. In addition, we reviewed functional and oncologic outcomes. RESULTS AND LIMITATIONS Mean age at treatment was 59.3 yr. Mean tumor size was 2.87 cm. Mean total operative time was 210 min while mean ischemic time was 23.9 min. Calyceal repair was required in 52.1% of procedures. Mean estimated blood loss was 131.5 ml. Sixty-nine percent of excised tumors were malignant, of which 2.7% exhibited positive surgical margins. The incidence of major complications was 8.2%. At up to 26 mo follow-up, there have been no documented recurrences and no significant change in serum creatinine (1.03 vs 1.04 mg/dl, p=0.84) or estimated glomerular filtration rate (eGFR) from baseline (82.2 vs 79.4 mg/ml per square meter, p=0.74). The study is limited by its retrospective nature, and the outcomes are likely influenced by the robust prior laparoscopic renal experience of each of the surgeons included in this study. CONCLUSIONS RAPN is a safe and efficacious approach for NSS, offering short ischemic times, as well as perioperative morbidity equivalent to other standard approaches. Moreover, RAPN is capable of providing patients with excellent functional and oncologic outcomes.

Does Citation Analysis Reveal Association Between h-Index and Academic Rank in Urology?

i raditionally, the world of academia has relied largely on peer review when appraising the merit of an individual faculty member, generally during eliberations for promotions or for admission into elite cademic societies. However entrenched in our academic ociety the peer-review process might be, it faces harsh riticism on the grounds of its relative secrecy and subectivity and the perceived notion that the process can be nduly influenced by politicking and gamesmanship. As uch, much interest has been generated in finding other, ore objective methods to appraise academicians’ conributions to their field. Although no single measure can ccount for every facet of an individual’s value to a rogram or department, many would agree that the prolivity to publish serves as one indicator of productivity. Although in use in the legal professions since the late 800s, the notion of incorporating bibliometric indexes nto the natural sciences was not proposed until 1955, ith Garfield’s description of the “impact factor.” Curently, databases such as the Thomson ISI Web of Scince (available from http://isiwebofknowledge.com) and he Scopus database (available from http://www.scopus. om) provide a wealth of dynamic bibliometric data that an be easily accessed through multiple search parameers, and allows for rapid scrutiny of an author’s output. Introduced in 2005 by Hirsch, the h-index has quickly ained considerable following in the academic commuity and has been adopted as the de facto metric in both he ISI and the Scopus databases because of its reliability nd ease of computation. Defined as the number of publications h that have each een cited at least h times in published reports, the -index seeks to temper the quantity of production with he perceived effect of an author’s contributions. For xample, if an author has 11 publications that have each een cited 11 times, then the h-index would be 11. The emainder of the author’s publications that do not have

Robot-assisted partial nephrectomy: Evaluation of learning curve for an experienced renal surgeon

PURPOSE The learning curve for robot-assisted partial nephrectomy (RAPN) has not been extensively studied. We therefore evaluated the learning curve of RAPN for a fellowship-trained laparoscopic surgeon with extensive prior experience with laparoscopic partial nephrectomy (LPN). We also examined the potential effect of tumor size on the learning curve. PATIENTS AND METHODS We prospectively evaluated 38 consecutive patients undergoing RAPN by a single surgeon (S.B.B.). Sixteen patients had tumors <2 cm, and 22 patients had tumors >2 cm. Warm ischemia times and overall operative times were recorded as indices of learning progression. RESULTS Average operative time for tumors <2 cm was 131.9 minutes (115.3-148.5 minutes) and for tumors >2 cm was 145.8 minutes (131.1-160.5 minutes). The difference between the operative times for tumors <2 and >2 cm was not statistically significant (p = 0.23). Average warm ischemia time for tumors <2 cm was 21 minutes (16.9-25.1 minutes) and for tumors >2 cm was 24.7 minutes (21.3-28.1 minutes). This difference was also not statistically significant (p = 0.20). Defined by the overall operative time, the learning curve for RAPN was 16 cases, and by ischemic time, the learning curve was 26 cases. Tumor size did not have an effect on the learning curve. CONCLUSIONS The learning curve for RAPN is short for surgeons already experienced with LPN. The learning curve for portions performed under warm ischemia is slightly longer, implying that the critical portions of the procedure require more experience to become facile. Tumor size does not appear to have a significant impact on the learning curve for surgeons experienced with LPN.

Positive Margin During Partial Nephrectomy: Does Cancer Remain in the Renal Remnant?

OBJECTIVE To examine the outcomes of patients with a positive surgical margin by gross and/or frozen examination during partial nephrectomy, in whom a re-resection of the margin or a completion nephrectomy was performed. METHODS Patients with renal cancer who underwent partial nephrectomy were considered. If the patient had a positive margin and underwent completion nephrectomy or re-excision of the margin, they were included. Patients with planned enucleation were excluded from the study. Clinical and pathologic information were reviewed to examine for residual cancer in the additionally resected tissue. RESULTS In the final cohort, 29 patients with a positive margin and subsequent complete parenchymal re-resection or completion nephrectomy were identified. Eight patients underwent nephrectomy, after which no residual cancer was found in the renal remnant. Twenty-one patients underwent total re-resection of the margin, of which two were found to have carcinoma. Renal functional outcomes revealed a decrease in estimated glomerular filtration rate of 25 mL/min/1.73 m(2) in patients who underwent radical nephrectomy, and 4 mL/min/1.73 m(2) in patients who underwent re-resection of the margin with preservation of the renal unit. CONCLUSIONS A positive surgical margin does not necessarily mean that cancer remains in the renal remnant in most cases. Therefore, radical nephrectomy or re-resection of the margin is overtreatment in many cases, but a small percentage of patients will harbor residual malignancy. Clinical correlation is recommended before reexcision or completion nephrectomy after a positive surgical margin, with careful consideration of the impact on subsequent renal function weighed against the possibility of residual disease.

Selective versus nonselective arterial clamping during laparoscopic partial nephrectomy: impact upon renal function in the setting of a solitary kidney in a porcine model.

INTRODUCTION Laparoscopic partial nephrectomy has emerged as a standard of care for small renal masses. Nevertheless, there remains concern over the potential for irreversible insult to the kidney as a result of exposure to warm ischemia. We aim to investigate the utility of selective segmental arterial clamping as a means to reduce the potential for ischemic damage to a solitary kidney during laparoscopic partial nephrectomy utilizing a porcine model. MATERIALS AND METHODS A total of 20 domestic swine were randomized into four equal groups. Each subject underwent laparoscopic radical nephrectomy to create the condition of a solitary kidney. On the contralateral side, a laparoscopic lower pole partial nephrectomy was performed, employing either selective or nonselective vascular clamping for either 60 or 90 minutes. Postoperatively, clinical status and serial serum studies were closely monitored for 1 week. RESULTS There were no intraoperative complications. The 90-minute nonselective clamping produced devastating effects, resulting in rapid deterioration into florid renal failure within 72 hours. The 60-minute nonselective clamping group experienced modest but significant rises in both blood urea nitrogen and creatinine. Both 60- and 90-minute selective clamping groups performed well, with no significant rises in creatinine over a 7-day period, and no instances of renal failure. CONCLUSIONS Selective arterial clamping is a safe and feasible means of vascular control during laparoscopic partial nephrectomy. In the porcine model, selective clamping appears to improve functional outcomes during prolonged periods of warm ischemic insult. Prospective evaluation of the technique in humans is necessary to determine if selective arterial control confers long-term functional benefits in patients with limited renal reserve.

Sliding-clip renorrhaphy provides superior closing tension during robot-assisted partial nephrectomy

OBJECTIVE Recently, our institution refined a technique for robot-assisted renorrhaphy utilizing sliding Weck Hem-O-Lock clips, which are tightened by the surgeon seated at the console and locked into place with a LapraTy clip. In addition to the relative ease of implementation, we believe that our technique also provides a superior strength of closure over other commonly used techniques. METHODS An in vivo porcine model was used to compare a sliding-clip technique against an assistant-placed LapraTy-only closure, and a surgeon-placed simple suture closure. A force gauge was used to record the maximum tension that could be applied during each closure method before the suture ripped through the renal parenchyma, thus illustrating the relative strength of each closure. RESULTS The simple suture closure performed relatively poorly, ripping through parenchyma at a mean force of 11.3 N. The LapraTy-only method allowed a maximum applicable mean force of 16.7 N. The sliding Weck clip with a LapraTy bolster provided the tightest closure, allowing for a mean force of 32.7 N before ripping through parenchyma. Statistical analysis reveals that a sliding-clip technique provides a significantly tighter closure than both of the other tested methods. CONCLUSION A sliding-clip technique allows for more tension to be safely applied to the closure of a partial nephrectomy defect than other commonly used methods. We believe that this is primarily attributable to the larger footprint of the Hem-O-Lock clip, which allows for the tension to be distributed over a greater surface area. The LapraTy then ensures the security of the closure by holding the Weck clip in place. Further studies are necessary to determine if this increased tension translates into appreciably better hemostasis.

Robot-assisted partial nephrectomy: current perspectives and future prospects.

The widespread adoption of laparoscopic partial nephrectomy (LPN) has been curtailed by its technical complexity. With the introduction of robotic technology, there is a potential for a shorter learning curve for minimally invasive nephron-sparing surgery (NSS). Initial published data on robot-assisted partial nephrectomy show promising perioperative outcomes comparable to large LPN series performed by highly experienced laparoscopic surgeons. Intraoperative parameters (operating room time, warm ischemia time, and blood loss) and short-term oncologic results demonstrate that this technique, unlike LPN, has a relatively short learning curve. Economic factors, as well as the necessity of an experienced bedside assistant, present the potential shortcomings of the procedure.

Percutaneous cryoablation of renal masses: Washington University experience of treating 129 tumours

For patients who are unfit for extirpative surgery, percutaneous cryoablation (PCA) presents a minimally‐invasive alternative for the treatment of renal masses. PCA has been demonstrated to be safe, with complication rates <10% being reported consistently. Studies have suggested that a minimal and insignificant decline in renal function can occur after PCA. Finally, among studies with a follow‐up >20 months, treatment success rates range from 75% to 96%. However, longer‐term oncological and functional results for patients treated with PCA are relatively limited. The present study profiles one of the largest reported experiences with PCA for renal masses: 129 tumours in 124 patients. Our complication rate was comparable to that observed in other reported studies. At a mean follow‐up of 30 months, treatment success was achieved in 87% of tumours, which is in line with published PCA success rates. On multivariable analysis, tumour size >3.0 cm was found to be significantly associated with treatment failure. A minimal but statistically significant renal functional decline was observed, with 20% of patients experiencing a progression in National Kidney Foundation‐Chronic Kidney Disease stage. On multivariable analysis, age >70 years, hilar tumour location and postoperative day 1 estimated glomerular filtration rate <60 mL/min/1.73 m2 were found to be significantly associated with renal functional decline. The present study confirms that PCA of renal masses represents a safe alternative to surgery in patients with substantial medical comorbidities. In the present cohort, baseline patient and tumour characteristics probably impact the risk of tumour recurrence, as well as renal disease progression, after PCA.