David A. Lifshitz

Background and Purpose: Clinical and surgical factors predict renal function decline after laparoscopic partial nephrectomy (LPN). Additional histopathologic predictors may be found in the specimen's nonneoplastic tissue but were not studied. This study investigated the significance of histologic findings in addition to other known predictors of renal function after LPN. Patients and Methods: Data of 150 patients who underwent LPN was analyzed. Renal function changes (median follow-up 15 months) were correlated with perioperative and histopathologic parameters. Three histopathologic features were evaluated and graded in the nonneoplastic parenchyma: Glomerulosclerosis, arteriosclerosis (AS), and interstitial fibrosis/tubular atrophy. Estimated GFR (eGFR) and percent decline on postoperative day 1 (POD1) and at the last follow-up were measured. Results: Median eGFR percent decline at POD1 and last follow-up was −17 and −10, respectively (Pvs artery only clamping (P=0.002), male sex (P=0.015), and larger tumor (P=0.02). Long-term loss of renal function was associated with POD1 eGFR decline (P=0.002) and the percentage of AS (P=0.01). The study limitations include a retrospective analysis leading to variability in the follow-up length and a small size cohort. Conclusions: LPN is associated with a favorable renal function outcome in most patients. Pathologic findings in the nonneoplastic tissue, in addition to clinical parameters, can be used to predict which patients are more likely to experience renal function impairment.

Background and Purpose: Angioembolization is often the first-line treatment for patients with renal angiomyolipoma (AML). Regrowth and repeated hemorrhage after embolization, however, remain a concern. Laparoscopic partial nephrectomy (LPN) is the definitive, minimally invasive treatment alternative. We compared the outcomes of LPN in patients who had a diagnosis of AML with patients with other renal tumors. Patients and Methods: : From a prospective LPN database, we identified patients with a final pathologic diagnosis of AML (group 1). The ability of preoperative imaging to predict AML final pathology results was studied. Surgical and postoperative outcomes in group 1 were compared with the outcomes of the rest of our LPN cohort (group 2). Results: Of 184 LPNs that were performed between 2002 and 2008, 14 (7.6%) patients and 15 renal units had a diagnosis of AML. Two patients underwent concomitant LPN and radiofrequency ablation (RFA) for multiple AML lesions. In group 1, only 33% of the patients had a preoperative diagnosis of AML. There were no significant differences in tumor size, age, preoperative estimated creatinine clearance, body mass index, and comorbidities between the groups. The mean estimated blood loss in groups 1 and 2 was 214 mL and 178 mL, respectively ( P = 0.5). The complication rates were similar between the groups. With a median follow-up of 15 months, no AML recurrences or bleeding was observed in group 1. Conclusions: The results of LPN or RFA, when appropriate, in AML patients are comparable to the results of LPN for other renal tumors. The preoperative imaging studies were a poor predictor of AML in patients who were undergoing LPN.

Purpose: To compare the perioperative and functional outcomes of patients with clinical T_1a and T_1b renal tumors after laparoscopic partial nephrectomy (LPN). Patients and Methods: Data of 184 patients who underwent LPN were retrieved from a prospective, Institutional Review Board-approved database. The patients were stratified for analysis into groups: 149 (81%) patients with clinical stage T_1a (group 1) and 35 (19%) patients with clinical stage T_1b (group 2). Perioperative and postoperative outcomes were compared. Results: No significant differences between groups 1 and 2 in warm ischemia time, estimated blood loss, operative time, conversion rate, intraoperative complication rate, and hospital stay were observed. The incidence of postoperative complications in group 2, however, was twice that of group 1 (25.7% vs 12%) (P = 0.04). Clinical staging correlated with the pathologic staging in 96% of the patients in group 1 and in only 71% in group 2 (P < 0.001). Upstaging to pT₂ or pT₃ occurred in 29% of the patients in group 2. High-grade tumors were more prevalent in group 2 (36% vs 12%) (P = 0.001). The number of patients with positive margin was higher in group 2, but the difference was not statistically significant. The mean decline in estimated creatinine clearance (median follow-up 18 months) was significantly higher in group 2. Conclusions: LPN in patients with tumors >4 cm, while safe and feasible in experienced hands, is associated with a higher postoperative complication rate, as well as a higher rate of pathologic upstaging. Such data should be discussed when counseling patients with larger tumors for LPN.

The kidney is often exposed to warm ischemia during laparoscopic partial nephrectomy. Warm ischemia time is associated with acute and possible long-term renal damage, particularly beyond a 30-minute threshold. We evaluated patient and tumor characteristics that might predict prolonged warm ischemia time. A prospective institutional database was searched for patients who underwent laparoscopic partial nephrectomy with renal vessel clamping. Warm ischemia time was treated as a continuous and a categorical (more or less than 30 minutes) variable. The association between warm ischemia time, and preoperative and surgical parameters was evaluated using linear and logistic regression analysis. The latter analysis was used to develop and internally validate a preoperative nomogram to predict warm ischemia time longer than 30 minutes. On multivariate linear regression analysis tumor size (coefficient 1.6, 95% CI 0.7-2.6, p = 0.001), body mass index (coefficient 0.3, 95% CI 0.1-0.5, p = 0.005) and central tumor location (coefficient 3.7, 95% CI 0.5-7, p = 0.02) were independent predictors of longer warm ischemia time. Patients with 2 or more of certain risk factors, including body mass index greater than 30 kg/m(2), tumor greater than 4 cm and a centrally located tumor, were 5 times more likely to have warm ischemia time greater than 30 minutes than patients without the risk factors (p = 0.002). A nomogram incorporating predictors of longer warm ischemia time showed 75.4% accuracy. Greater tumor size, central tumor location and higher body mass index are associated with longer warm ischemia time. By incorporating these 3 risk factors into a nomogram prolonged warm ischemia time (greater than 30 minutes) can be accurately predicted preoperatively.

We assessed the efficacy of papaverine hydrochloride, a commonly used smooth muscle relaxant, for the treatment of renal colic as a single agent and in combination with sodium diclofenac. A prospective, single-blind clinical study was performed at 2 centers. A total of 86 patients with acute renal colic were randomized to 3 treatment groups of 120 mg intravenous papaverine hydrochloride (29), 75 mg intramuscular sodium diclofenac (30), and papaverine hydrochloride plus sodium diclofenac (27). Pain intensity was assessed with the Visual Analog Scale at 0, 20 and 40 minutes after treatment. Further analgesia given at patient request consisted of 1 mg/kg intramuscular meperidine. Urinalysis, complete blood evaluation and imaging were performed in all patients. All adverse effects were recorded. Baseline characteristics were similar in the 3 groups. Pain intensity decreased significantly (p <0.01) after 20 and 40 minutes in all groups. Papaverine hydrochloride was as effective as sodium diclofenac in alleviating pain and the combined treatment group showed a slight trend of more rapid relief. Significantly more patients in the papaverine group required further analgesia and 4 patients (14.8%) reported minor adverse effects (dizziness in 3, sleepiness in 1). Papaverine hydrochloride is as effective as sodium diclofenac for the short-term relief of acute renal colic pain and may be advantageous in patients with contraindications for nonsteroidal anti-inflammatory drugs. However, sodium diclofenac appears to provide a longer effective analgesia.

Bladder augmentation is most commonly performed with ileum. However, porcine small intestinal submucosa has been reported as a substitute for bowel for incorporation into the urinary tract. We assessed the feasibility and long-term 12-month results of laparoscopic bladder augmentation with ileum or multilayered small intestinal submucosa (Cook Biotech, Spencer, Indiana) in a porcine model. We performed laparoscopically assisted hemicystectomy and bladder augmentation in 24 female Yucatan mini-pigs using an ileal segment (12) or multilayered small intestinal submucosa (12). The followup protocol included anesthetic bladder capacity, renal ultrasonography and serum chemistry. At 3, 6 and 12 months, respectively, 4 animals per group were scheduled for sacrifice and pathological analysis. Despite longer anastomotic time in the multilayered small intestinal submucosa group (120 versus 91 minutes, p = 0.026) total operative time was similar in the 2 groups. In each group bladder capacity increased with time but by 12 months bladder capacity was significantly better in the bowel than in the small intestinal submucosa group (825 versus 431 cc, p = 0.016). At 3 months pathological evaluation revealed that the multilayered regenerated bladder patch had shrunken and by 6 months it was replaced by dense calcified scar tissue. Long-term 6 and 12-month bladder capacity in the small intestinal submucosa group was the result of the regeneration of native bladder with exclusion of the whole multilayered patch in the majority of cases. Laparoscopic bladder augmentation using multilayered small intestinal submucosa produced functional and pathological results inferior to those of bowel at 12-month followup in a porcine model.