Michael D. Stifelman

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.

A Prospective, Blinded Comparison of Magnetic Resonance (MR) Imaging–Ultrasound Fusion and Visual Estimation in the Performance of MR-targeted Prostate Biopsy: The PROFUS Trial

BACKGROUND Increasing evidence supports the use of magnetic resonance (MR)-targeted prostate biopsy. The optimal method for such biopsy remains undefined, however. OBJECTIVE To prospectively compare targeted biopsy outcomes between MR imaging (MRI)-ultrasound fusion and visual targeting. DESIGN, SETTING, AND PARTICIPANTS From June 2012 to March 2013, prospective targeted biopsy was performed in 125 consecutive men with suspicious regions identified on prebiopsy 3-T MRI consisting of T2-weighted, diffusion-weighted, and dynamic-contrast enhanced sequences. INTERVENTION Two MRI-ultrasound fusion targeted cores per target were performed by one operator using the ei-Nav|Artemis system. Targets were then blinded, and a second operator took two visually targeted cores and a 12-core biopsy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Biopsy information yield was compared between targeting techniques and to 12-core biopsy. Results were analyzed using the McNemar test. Multivariate analysis was performed using binomial logistic regression. RESULTS AND LIMITATIONS Among 172 targets, fusion biopsy detected 55 (32.0%) cancers and 35 (20.3%) Gleason sum ≥7 cancers compared with 46 (26.7%) and 26 (15.1%), respectively, using visual targeting (p=0.1374, p=0.0523). Fusion biopsy provided informative nonbenign histology in 77 targets compared with 60 by visual (p=0.0104). Targeted biopsy detected 75.0% of all clinically significant cancers and 86.4% of Gleason sum ≥7 cancers detected on standard biopsy. On multivariate analysis, fusion performed best among smaller targets. The study is limited by lack of comparison with whole-gland specimens and sample size. Furthermore, cancer detection on visual targeting is likely higher than in community settings, where experience with this technique may be limited. CONCLUSIONS Fusion biopsy was more often histologically informative than visual targeting but did not increase cancer detection. A trend toward increased detection with fusion biopsy was observed across all study subsets, suggesting a need for a larger study size. Fusion targeting improved accuracy for smaller lesions. Its use may reduce the learning curve necessary for visual targeting and improve community adoption of MR-targeted biopsy.

Robot Assisted Laparoscopic Partial Nephrectomy: Initial Experience

PURPOSE Advances in laparoscopy have made laparoscopic partial nephrectomy a technically feasible procedure but it remains challenging to even experienced laparoscopists. We hypothesized that robotic assisted laparoscopic partial nephrectomy may make this procedure more efficacious than the standard laparoscopic approach. MATERIALS AND METHODS Ten patients with a mean age of 58 years and mean tumor size of 2.0 cm underwent robotic assisted laparoscopic partial nephrectomy and another 10 with a mean age of 61 years and mean tumor size of 2.18 cm underwent laparoscopic partial nephrectomy, as performed by a team of 2 surgeons (MS and ST) between May 2002 and January 2004. Demographic data, intraoperative parameters and postoperative data were compared between the 2 groups. RESULTS There were no significant differences in patient demographics between the 2 groups. Intraoperative data and postoperative outcomes were statistically similar. In the 10 patients who underwent robotic assisted laparoscopic partial nephrectomy there were 2 intraoperative complications. There was 1 conversion in the laparoscopic partial nephrectomy group. CONCLUSIONS Robotic assisted laparoscopic partial nephrectomy is a safe and feasible procedure in patients with small exophytic masses. The robotic approach to laparoscopic partial nephrectomy does not offer any clinical advantage over conventional laparoscopic nephrectomy.

Changes in Renal Function Following Nephroureterectomy May Affect the Use of Perioperative Chemotherapy

BACKGROUND Nephroureterectomy alone fails to adequately treat many patients with advanced upper tract urothelial carcinoma (UTUC). Perioperative platinum-based chemotherapy has been proposed but requires adequate renal function. OBJECTIVE Our aim was to determine whether the ability to deliver platinum-based chemotherapy following nephroureterectomy is affected by postoperative changes in renal function. DESIGN, SETTINGS, AND PARTICIPANTS We retrospectively reviewed data on 388 patients undergoing nephroureterectomy for UTUC between 1991 and 2009. Four institutions were included. INTERVENTION All patients underwent nephroureterectomy. MEASUREMENTS All patients had serum creatinine measured before and after surgery. The value closest to 3 mo after surgery was taken as the postoperative value (range: 2-52 wk). Estimated glomerular filtration rate (eGFR) was calculated using the abbreviated Modification of Diet in Renal Disease study equation. eGFR values before and after surgery were compared using the paired t test. We chose an eGFR of 45 and 60 ml/min per 1.73 m(2) as possible cut-offs for chemotherapy eligibility and compared eligibility before and after surgery using the chi-square test. RESULTS AND LIMITATIONS Our cohort of 388 patients included 233 men (60%) with a median age of 70 yr. Mean eGFR decreased by 24% after surgery. Using a cut-off of 60 ml/min per 1.73 m(2), 49% of patients were eligible for chemotherapy before surgery, but only 19% of patients remained eligible postoperatively. Using a cut-off of 45 ml/min per 1.73 m(2), 80% of patients were eligible preoperatively, but only 55% remained eligible after surgery. This distribution persisted when we limited the analysis to patients with advanced pathologic stage (T3 or higher). Patients older than the median age of 70 yr were more likely to be ineligible for chemotherapy both pre- and postoperatively by either definition, and they were significantly more likely to have an eGFR <45 ml/min per 1.73 m(2) postoperatively, regardless of their starting eGFR. This study is limited by its retrospective nature, and there was some variability in the timing of postoperative serum creatinine measurements. CONCLUSIONS eGFR is significantly diminished after nephroureterectomy, particularly in elderly patients. These changes in renal function likely affect eligibility for adjuvant cisplatin-based therapy. Accordingly, we suggest strong consideration of neoadjuvant regimens.

Robotic Dismembered Pyeloplasty: A 6-Year, Multi-Institutional Experience

PURPOSE The introduction of the da Vinci Surgical System to perform complex reconstructive procedures, such as repair of ureteropelvic junction obstruction, has helped to overcome some of the technical challenges associated with laparoscopy. We review our large multi-institutional experience with long-term followup of robotic dismembered pyeloplasty. MATERIALS AND METHODS A total of 140 patients from 3 university medical centers underwent robotic dismembered pyeloplasty. An institutional review board approved retrospective chart review was performed to collect demographic, preoperative, operative and postoperative data. Patients were analyzed as an entire cohort and then divided into various subgroups. RESULTS Of the cases 117 (84.6%) were primary repairs and 23 (16.4%) were secondary repairs. There were 13 (9.3%) patients who underwent concomitant stone extraction and 5 (3.6%) procedures were performed on patients with solitary kidneys. A crossing vessel was found in 77 (55%) patients. Mean operative time was 217 minutes (range 80 to 510), estimated blood loss was 59.4 ml (range 10 to 600), mean length of hospital stay 2.1 days (range 0.75 to 7) and mean followup was 29 months (range 3 to 63). Radiographic resolution of obstruction on first postoperative diuretic renal scan or excretory urogram was noted in 134 patients (95.7%). There was a 7.1% major complication rate and a 2.9% minor complication rate. No statistically significant differences were found in any parameters among patients from the various cohorts. CONCLUSIONS To our knowledge this review represents the largest multi-institutional experience of robotic dismembered pyeloplasty with long-term followup. Robotic pyeloplasty appears to be safe, durable and efficacious for primary and secondary ureteropelvic junction obstruction with or without concomitant stone extraction, and for patients with a solitary kidney.

Effect of Warm Ischemia Time During Laparoscopic Partial Nephrectomy on Early Postoperative Glomerular Filtration Rate

PURPOSE We evaluated the effect of warm ischemia time on early postoperative renal function following laparoscopic partial nephrectomy. MATERIALS AND METHODS Of 453 patients who were surgically treated for renal tumors between May 2001 and September 2007, and who were identified in our database 128 underwent laparoscopic partial nephrectomy. Of these 128 patients 101 who were evaluable had complete demographic, operative, preoperative and early postoperative data available. Renal function was estimated using the glomerular filtration rate. Warm ischemia time was stratified into 4 interval groups and also analyzed based on different time cutoffs. Ultimately we also tested the relationship between postoperative renal failure, and preoperative factors and warm ischemia time. RESULTS Warm ischemia time interval analysis was not significant. However, when analyzing the effect of warm ischemia time cutoffs, patients with warm ischemia time greater than 40 minutes had a significantly greater decrease in the glomerular filtration rate (p = 0.03) and a lower glomerular filtration rate postoperatively. The incidence of renal function impairment was more than 2-fold higher in those with a warm ischemia time of greater than 40 minutes than in the other groups (p = 0.077). Warm ischemia time was significant on univariate analysis when only patients with a preoperative glomerular filtration rate of 60 ml per minute per 1.73 m(2) or greater were analyzed. However, this did not hold as an independent predictor of postoperative renal function impairment on multivariate analysis. The preoperative glomerular filtration rate was the only independent predictor of postoperative renal function impairment. CONCLUSIONS A warm ischemia time of 40 minutes appears to be an appropriate cutoff, after which a significantly greater decrease in renal function occurs after laparoscopic partial nephrectomy. The preoperative glomerular filtration rate was the only independent predictor of an increased risk of renal insufficiency following laparoscopic partial nephrectomy.

Complications after robotic partial nephrectomy at centers of excellence: multi-institutional analysis of 450 cases.

PURPOSE We evaluated the incidence of perioperative complications after robotic partial nephrectomy. MATERIALS AND METHODS We retrospectively reviewed the records of patients treated with robotic assisted partial nephrectomy across the 4 participating institutions. Demographic, blood loss, warm ischemia time, and intraoperative and postoperative complication data were collected. All complications were graded according to the Clavien classification system. RESULTS A total of 450 consecutive robotic assisted partial nephrectomies were done between June 2006 and May 2009. Overall 71 patients (15.8%) had a complication, including intraoperative and postoperative complications in 8 (1.8%) and 65 (14.4%), respectively. Hemorrhage developed in 2 patients (0.2%) intraoperatively and in 22 (4.9%) postoperatively. Seven patients (1.6%) had urine leakage. As classified by the Clavien system, complications were grade I-II in 76.1% of cases and grade III-IV in 23.9%. Robotic assisted partial nephrectomy was converted to open or conventional laparoscopic surgery in 3 patients (0.7%) and to radical nephrectomy in 7 (1.6%). There were no deaths. CONCLUSIONS Current data indicate that robotic assisted partial nephrectomy is safe. Most postoperative complications are Clavien grade I or II, or can be managed conservatively.

Positive Surgical Margins in Robot-Assisted Partial Nephrectomy: A Multi-Institutional Analysis of Oncologic Outcomes (Leave No Tumor Behind)

PURPOSE Expanding indications for robot-assisted partial nephrectomy raise major oncologic concerns for positive surgical margins. Previous reports showed no correlation between positive surgical margins and oncologic outcomes. We report a multi-institutional experience with the oncologic outcomes of positive surgical margins on robot-assisted partial nephrectomy. MATERIALS AND METHODS Pathological and clinical followup data were reviewed from an institutional review board approved, prospectively maintained joint database from 5 institutions. Tumors with malignant pathology were isolated and statistically analyzed for demographics and oncologic followup. The log rank test was used to compare recurrence-free and metastasis-free survival between patients with positive and negative surgical margins. The proportional hazards method was used to assess the influence of multiple factors, including positive surgical margins, on recurrence and metastasis. RESULTS A total of 943 robot-assisted partial nephrectomies for malignant tumors were successfully completed. Of the patients 21 (2.2%) had positive surgical margins on final pathological assessment, resulting in 2 groups, including the 21 with positive surgical margins and 922 with negative surgical margins. Positive surgical margin cases had higher recurrence and metastasis rates (p<0.001). As projected by the Kaplan-Meier method in the population as a whole at followup out to 63.6 months, 5-year recurrence-free and metastasis-free survival was 94.8% and 97.5%, respectively. There was a statistically significant difference in recurrence-free and metastasis-free survival between patients with positive and negative surgical margins (log rank test<0.001), which favored negative surgical margins. Positive surgical margins showed an 18.4-fold higher HR for recurrence when adjusted for multiple tumors, tumor size, tumor growth pattern and pathological stage. CONCLUSIONS Positive surgical margins on final pathological evaluation increase the HR of recurrence and metastasis. In addition to pathological and molecular tumor characteristics, this should be considered to plan appropriate management.

Perioperative Complications of Robot-assisted Partial Nephrectomy: Analysis of 886 Patients at 5 United States Centers

OBJECTIVE To review complications of robot-assisted partial nephrectomy (RAPN) at 5 centers, as classified by the Clavien system. MATERIALS AND METHODS A multi-institutional analysis of prospectively maintained databases assessed RAPN complications. From June 2007 to November 2011, 886 patients at 5 United States centers underwent RAPN. Patient demographics, perioperative outcomes, and complications data were collected. Complication severity was classified by Clavien grade. RESULTS Mean (standard deviation) data were patient age, 59.4 (11.4) years; age-adjusted Charlson Comorbidity Index, 3.0 (1.9); radiographic tumor size, 3.0 (1.6) cm; nephrometry score, 6.9 (2.0); and warm ischemia time, 18.8 (9.0) minutes. Median blood loss was 100 mL (interquartile range, 100-250 mL). Of the 886 patients, intraoperative complications occurred in 23 patients (2.6%) and 139 postoperative complications occurred in 115 patients (13.0%) for a total complication rate of 15.6%. Among the 139 postoperative complications, 43 (30.9%) were classified as Clavien 1, 64 (46.0%) were Clavien 2, 21 (15.1%) were Clavien 3, and 11 (7.9%) were Clavien 4. No complication-related deaths occurred. Intraoperative hemorrhage occurred in 9 patients (1.0%) and postoperative hemorrhage in 51 (5.8%). Forty-one patients (4.6%) required a perioperative blood transfusion, 10 (1.1%) required angioembolization, and 2 (0.2%) required surgical reexploration for postoperative hemorrhage. Urine leaks developed in 10 patients (1.1%): 3 (0.3%) required ureteral stenting, and 2 (0.2%) required percutaneous drainage. Acute postoperative renal insufficiency or renal failure developed in 7 patients (0.8%), 2 of whom required hemodialysis. The RENAL (radius, exophytic/endophytic properties of the tumor, nearness of tumor deepest portion to the collecting system or sinus, anterior/posterior descriptor and the location relative to polar lines) nephrometry scoring system accurately predicted RAPN complication rates. CONCLUSION Complication rates in this large multicenter series of RAPN appear to be acceptable and comparable with other nephron-sparing modalities. Most complications (77.0%) are Clavien 1 and 2 and can be managed conservatively.

Bosniak Category IIF Designation and Surgery for Complex Renal Cysts

PURPOSE We investigated whether adding the IIF categorization improved the accuracy of Bosniak renal cyst classification, as evidenced by a low rate of progression in IIF lesions and a high rate of malignancy in category III lesions. MATERIALS AND METHODS We retrospectively reviewed the records of patients with complex renal cysts categorized as a Bosniak IIF or III. Surveillance imaging and pathological outcomes of category IIF cysts were recorded to determine radiological predictors of progression. Pathological outcomes of category III cysts were recorded to determine the malignancy rate. RESULTS A total of 112 patients met study inclusion criteria, of whom 81 were initially diagnosed with a category IIF cyst and 31 had a Bosniak category III cyst. At a median followup of 15 months 14.8% of Bosniak IIF lesions progressed in complexity with a median time to progression of 11 months (maximum greater than 4 years). There were no differences in tumor or patient characteristics between cysts that progressed and those that remained stable. In the 33 patients with Bosniak III lesions who underwent surgical extirpation the malignancy rate was 81.8%. Most patients had low stage, low grade disease and remained recurrence-free at a median followup of 6 months. CONCLUSIONS Adding the IIF category has increased the accuracy and clinical impact of the Bosniak categorization system, as evidenced by a low rate of progression in category IIF cysts and an increased rate of malignancy in surgically treated category III lesions compared to those in historical controls.