George K. Chow

Comparative effectiveness for survival and renal function of partial and radical nephrectomy for localized renal tumors: A systematic review and meta-analysis

PURPOSE The relative effectiveness of partial vs radical nephrectomy remains unclear in light of the recent phase 3 European Organization for the Research and Treatment of Cancer trial. We performed a systematic review and meta-analysis of partial vs radical nephrectomy for localized renal tumors, considering all cause and cancer specific mortality, and severe chronic kidney disease. MATERIALS AND METHODS Cochrane Central Register of Controlled Trials, MEDLINE®, EMBASE®, Scopus and Web of Science® were searched for sporadic renal tumors that were surgically treated with partial or radical nephrectomy. Generic inverse variance with fixed effects models were used to determine the pooled HR for each outcome. RESULTS Data from 21, 21 and 9 studies were pooled for all cause and cancer specific mortality, and severe chronic kidney disease, respectively. Overall 31,729 (77%) and 9,281 patients (23%) underwent radical and partial nephrectomy, respectively. According to pooled estimates partial nephrectomy correlated with a 19% risk reduction in all cause mortality (HR 0.81, p < 0.0001), a 29% risk reduction in cancer specific mortality (HR 0.71, p = 0.0002) and a 61% risk reduction in severe chronic kidney disease (HR 0.39, p < 0.0001). However, the pooled estimate of cancer specific mortality for partial nephrectomy was limited by the lack of robustness in consistent findings on sensitivity and subgroup analyses. CONCLUSIONS Our findings suggest that partial nephrectomy confers a survival advantage and a lower risk of severe chronic kidney disease after surgery for localized renal tumors. However, the results should be evaluated in the context of the low quality of the existing evidence and the significant heterogeneity across studies. Future research should use higher quality evidence to clearly demonstrate that partial nephrectomy confers superior survival and renal function.

Percutaneous Renal Cryoablation: Experience Treating 115 Tumors

PURPOSE We determined technical feasibility, safety and short-term outcomes following percutaneous renal cryoablation. MATERIALS AND METHODS We performed a retrospective review of 115 renal tumors in 110 patients treated with percutaneous cryoablation. Specific attention was directed to tumor characteristics, hospital course, complications, technical success and treatment success based on followup imaging. RESULTS Mean tumor size was 3.3 cm (range 1.5 to 7.3), including 29 tumors 4.0 cm or larger and 21 tumors in the anterior kidney. Of 90 renal mass biopsies performed 52 (58%) showed renal cell carcinoma. All patients were admitted to the hospital following cryoablation and most (87%) were discharged home the next day (range 1 to 12 days). There were 7 major complications associated with the 113 cryoablation procedures (6%). Technical success was achieved in 112 of the 115 (97%) treated tumors and 3 residual tumors were seen on 3-month followup imaging. There has been no local progression in 80 tumors (100% treatment success) followed 3 months or longer (mean 13.3 months). CONCLUSIONS Percutaneous renal cryoablation is technically feasible and relatively safe. With experience many anterior tumors and tumors larger than 4 cm can be successfully treated. Long-term followup remains necessary to prove treatment durability.

Obesity in living kidney donors: clinical characteristics and outcomes in the era of laparoscopic donor nephrectomy.

Acceptance of obese individuals as living kidney donors is controversial related to possible increased risk for surgical complications and concern that obesity may contribute to long‐term renal disease. We retrospectively examined 553 consecutive hand‐assisted laparoscopic living kidney donations between October 1, 1999 and April 1, 2003. We stratified donors into quartiles by baseline body mass index (BMI) assessing perioperative complications and 6–12 months post‐donation metabolic and renal function. Compared to BMI <25 kg/m2, high BMI donors (≥35 kg/m2) had slightly longer operative times (mean increase 19 min), more overall perioperative complications (mostly minor wound complications), yet the same low rate of major surgical complications (conversion to open and re‐operation) and similar length‐of‐stay (2.3 vs. 2.4 days). At 6–12 months after donation (mean 11 months), renal function and microalbuminuria did not differ with BMI. These results suggest that laparoscopic donor nephrectomy is generally safe in selected obese donors and does not result in a high rate of major perioperative complications. Obese donors have higher baseline cardiovascular risk and warrant risk reduction for long‐term health. While early results are encouraging, we advocate careful study of obese donors and do not support their widespread use until longer follow‐up is available.

Complications following 573 Percutaneous Renal Radiofrequency and Cryoablation Procedures

PURPOSE To review complications related to percutaneous renal tumor ablation. MATERIALS AND METHODS Prospectively collected data related to renal radiofrequency (RF) ablation and cryoablation procedures performed from May 2000 through November 2010 were reviewed. This included 573 renal ablation procedures performed in 533 patients to treat 633 tumors. A total of 254 RF ablation and 311 cryoablation procedures were performed; eight patients underwent simultaneous RF ablation and cryoablation. The mean age of patients at the time of the procedure was 70 years (range, 24-93 y), and 382 of 573 procedures (67%) were performed in male patients. Complications were recorded according to the Clavien-Dindo classification scheme. Duration of hospitalization was also documented. RESULTS Of the 573 procedures, 63 produced complications (11.0% overall complication rate). There were 66 reported complications, of which 38 (6.6% of total procedures) were Clavien-Dindo grade II-IV major complications; there were no deaths. Major complication rates did not differ statistically (P = .15) between cryoablation (7.7%; 24 of 311) and RF ablation (4.7%; 12 of 254). Of the complications related to cryoablation, bleeding and hematuria were most common. Bleeding during cryoablation was associated with advanced age, increased tumor size, increased number of cryoprobes, and central position (P < .05). Of those treated with RF ablation, nerve and urothelial injury were most common. Mean hospitalization duration was 1 day for RF ablation and cryoablation. CONCLUSIONS Complications related to percutaneous renal ablation are infrequent. Recognition of potential complications and associated risk factors can allow optimization of periprocedural care.

Percutaneous Ablation of Renal Masses Measuring 3.0 cm and Smaller: Comparative Local Control and Complications After Radiofrequency Ablation and Cryoablation

OBJECTIVE The purpose of this article is to compare the efficacy and complication rates of percutaneous radiofrequency ablation (RFA) and cryoablation in the treatment of renal masses measuring 3.0 cm and smaller. MATERIALS AND METHODS A retrospective review was performed of 385 patients with 445 tumors measuring 3.0 cm or smaller treated with thermal ablation from 2000 through 2010. Two hundred fifty-six tumors in 222 patients were treated with RFA (mean [± SD] tumor size, 1.9 ± 0.5 cm), and 189 tumors in 163 patients were treated with cryoablation (mean tumor size, 2.3 ± 0.5 cm). Major complications and efficacy as measured by technical success and local tumor recurrence rates were recorded. RESULTS There were five (1.1%) technical failures, including one (0.4%) among tumors treated with RFA and four (2.1%) among tumors treated with cryoablation (p = 0.17). Of the 218 tumors treated with RFA and with follow-up beyond 3 months, seven (3.2%) developed local tumor recurrence, at a mean of 2.8 years after treatment (range, 1.2-4.1 years). Of the 145 tumors treated with cryoablation and with follow-up beyond 3 months, four (2.8%) developed local tumor recurrence at a mean of 0.9 years after treatment (range, 0.3-1.6 years). For biopsy-proven renal cell carcinoma, estimated local recurrence-free survival rates at 1, 3, and 5 years after RFA were 100%, 98.1%, and 98.1%, respectively, compared with 97.3%, 90.6%, and 90.6%, respectively, after cryoablation (p = 0.09). Major complications occurred after 4.3% (10/232) of RFAs and 4.5% (8/176) of cryoablation procedures (p = 0.91). CONCLUSION RFA and cryoablation are both effective in the treatment of renal masses measuring 3 cm or smaller. Major complications with either procedure are infrequent.

Percutaneous Renal Cryoablation: Local Control at Mean 26 Months of Followup

PURPOSE We retrospectively determined the efficacy of percutaneous renal cryoablation based on a mean followup of more than 2 years. MATERIALS AND METHODS Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act compliant retrospective study. Informed consent was waived. From March 2003 through March 2007, 91 patients with 93 tumors underwent 92 percutaneous cryoablation procedures. Technical success was defined as extension of the ice ball beyond the tumor margin and post-ablation images showing no contrast enhancement in the area encompassing the original tumor within 3 months of the procedure. Local tumor progression was defined as new enhancement in the ablated tumor or an increase in ablated tumor size beyond 3 months after the procedure. Complications were defined using the National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. RESULTS Mean followup was 26 months (range 5 to 61, SD ±13) and mean tumor size was 3.4 cm (range 1.5 to 7.3, SD ±1.2). Major complications occurred in 6 of 91 patients (7%) or after 8 of 92 (9%) procedures. Technically successful ablation was performed in the treatment of 89 of the 93 (96%) tumors or 87 of the 91 patients (96%). Of the 83 tumors with followup longer than 3 months only a single case (1%) of local tumor progression occurred. Overall local control was achieved in 86 of 91 (95%) patients or 88 of 93 (95%) tumors. CONCLUSIONS Midterm followup of percutaneous renal cryoablation shows durability of this treatment method with a low incidence of tumor recurrence beyond 3 months.

The Evolution of Ureteroscopy: A Modern Single-Institution Series

OBJECTIVES To evaluate a modern ureteroscopy series, including the use of new technological advances, operative procedures, and potential complications, at a single institution and to compare our current experience with our prior published series and the current literature. MATERIAL AND METHODS We retrospectively reviewed 1000 consecutive ureteroscopies performed in 961 patients from December 1999 to February 2003 at our institution. RESULTS Semirigid and flexible ureteroscopes were used in 60.3% and 37.0% of the cases, respectively. In 2.6% of cases, a combination of both rigid and flexible ureteroscopes was required. The most common indications for ureteroscopy were as follows: stone, 57.9%; diagnostic, 20.6%; and urothelial carcinoma, 12.6%. Of the stones treated, 31.8% were proximal or middle and 59.1% distal. The overall, proximal, and distal stone-free rates were 91.7%, 87.3%, and 94.2%, respectively. Average operative time was 81 minutes (range, 5-280 minutes). Average follow-up was 2.36 months (range, 1-24 months). The overall complication rate was 1.9% (18/961), including a 0.2% (2/961) incidence of ureteral strictures. CONCLUSION Current practice trends have shifted to an increased use of flexible ureteroscopes and more frequent ureteroscopic treatment of proximal calculi. Our single treatment stone-free rates are competitive with quoted shock wave lithotripsy success. In addition, there has been a decrease in ureteroscopic-associated complications in our series, with no ureteral avulsions. The improvements in treatment success and decrease in complications may be secondary to advances in ureteroscopic technology.

Percutaneous Cryoablation of Renal Masses ≥3 cm: Efficacy and Safety in Treatment of 108 Patients

PURPOSE To evaluate our single institution experience with percutaneous cryoablation of renal masses >or=3 cm in diameter for complications and short-term outcomes. PATIENTS AND METHODS Between March 2003 and February 2009, 108 patients with 110 renal masses >or=3 cm in diameter were treated with percutaneous cryoablation therapy. Technical success of the ablation procedure, complications, and evidence for local tumor recurrence were evaluated for each patient. RESULTS Average maximal renal tumor diameter was 4.1 cm (range 3.0-8.3 cm; standard deviation 1.1 cm). A single cryoablation procedure was performed for treatment of each patient. A technically successful ablation was achieved for 107 of 110 (97%) tumors. The three technical failures all resulted from incomplete cryoablation of the deepest margin of a centrally located renal tumor. A total of 9 severe adverse events occurred in six patients, resulting in an 8% major complication rate. Two patients in whom major complications developed were part of the group of only four patients for whom ablation was performed for tumors > 7 cm in diameter. There were no procedural-related deaths. No evidence for local tumor recurrence was identified in any patients with follow-up contrast-enhanced CT or MRI obtained 3 months or longer from the time of the ablation. Follow-up in these patients averaged 15 months (range 3-42 mos). CONCLUSION Percutaneous cryoablation of renal masses >or=3 cm in diameter can be performed with high technical success and low complication rates. Extra scrutiny is needed during cryoablation of central renal masses to make sure the ablation zone extends to include the deepest margin of the tumor. Although our experience is limited, percutaneous cryoablation of renal tumors > 7 cm in diameter may be associated with increased complications. The lack of local renal tumor recurrences seen in this study on short-term follow-up is encouraging, but long-term follow-up remains necessary to ensure treatment durability.

Transureteroureterostomy Revisited: Long-Term Surgical Outcomes

PURPOSE Transureteroureterostomy is a treatment alternative for ureteral obstruction when more conventionally reconstructive techniques are not feasible. We report on long-term outcomes of patients treated with transureteroureterostomy. MATERIALS AND METHODS A retrospective chart review of all patients treated with transureteroureterostomy from January of 1985 to February of 2007 was performed. RESULTS We identified 63 patients who underwent transureteroureterostomy at our institution. Average treatment age was 31.5 years (range 1 to 83). Transureteroureterostomy was performed for 21 (33%) malignant and 42 (67%) benign indications. Reconstructions were 30 right-to-left (47.6%) and 33 left-to-right (52.4%) with 21 concurrent urinary diversions. There were 16 patients (25.4%) who received radiation before transureteroureterostomy. Postoperative complications occurred in 15 (23.8%) patients and were more common in those undergoing diversion for malignancy. Mean followup was 5.8 years (range 0.1 to 22.2) and 5 patients were lost to followup. Of the 56 patients with followup imaging the transureteroureterostomy was patent in 54 (96.4%) and obstructed in 2 (3.6%). Mean preoperative and recent calculated glomerular filtration rate for this cohort were 62.8 (range 13 to 154) and 71.8 (range 22 to 141) ml per minute, respectively (p = 0.04). Stone disease developed in 8 patients, and was treated with percutaneous nephrolithotomy (2), spontaneous passage (2), ureteroscopy (1) and surveillance (3). Subsequent urological intervention was required for obstruction or revision in 6 (10.3%) patients. CONCLUSIONS We demonstrated the long-term safety and effectiveness of transureteroureterostomy with sustained improvement of renal function compared to preoperative status. Recurrent stricture, distal obstruction and stone disease occur in a small percentage of patients, and can be treated in most with minimal intervention.

Prospective Double-Blind Study of Effect of Ketorolac Administration after Laparoscopic Urologic Surgery

BACKGROUND AND PURPOSE To decrease postoperative dependence on narcotics for analgesia, we have evaluated ketorolac as an adjunct to perioperative pain control in patients undergoing laparoscopic urologic surgery. PATIENTS AND METHODS Sixty-five patients (34 male, 31 female) were randomized to receive either ketorolac tromethamine (15-30 mg IV q 6 h) or placebo prior to laparoscopic surgery. Patient-controlled analgesia in the form of morphine sulfate was provided. Operative factors such as the type of surgery, operative time, and estimated blood loss were recorded. Postoperative factors such as analog pain score (range 0-10), narcotic usage, and length of stay were evaluated. RESULTS Fifty-five patients completed the study. The average pain score was 2.2 and 4.5 for the ketorolac and placebo groups, respectively (P < 0.005). The mean amounts of total morphine used were 39.2 mg (ketorolac) and 62.5 mg (placebo) (P = 0.077). The length of stay was not significantly different in the ketorolac (2.5 days) and placebo (2.6 days) groups (P = 0.74). Operative times (P = 0.21) and estimated blood loss (P = 0.60) were not significantly different in the two groups. Ketorolac did not adversely affect renal function; serum creatinine changes were not significantly different from those in the patients receiving placebo (P = 0.50). Laparoscopic pyeloplasty necessitated more narcotic analgesia than did other laparoscopic procedures (P = 0.05). CONCLUSION Ketorolac decreases the subjective perception of pain after laparoscopic urologic surgery. It is suggested that ketorolac administration decreases the amount of narcotic usage as well. Time to resumption of oral intake and length of hospital stay were not influenced by use of ketorolac.