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Purpose of Review: This review provides an overview of the recent publications on kidney-sparing-surgery (KSS) for upper tract urothelial carcinoma (UTUC), an alternative to radical nephroureterectomy (RNU) for an increasing number of indications., Recent Findings: Recent studies highlight comparable survival outcomes between KSS [ureterorenoscopy with tumour ablation (URS) or segmental ureteral resection (SUR)] and RNU, even in high-risk UTUC patients. KSS has shown to preserve renal function without significantly compromising oncologic control in appropriately selected patients. Included literature also researched surgical complications, surveillance strategies, such as second-look ureteroscopy, and comparative cost analyses., Summary: Over the past two and a half years, studies have emphasized the growing usage of URS and SUR in treating selected UTUC patients. Recent literature has remarkably included relatively large numbers of typically high-risk patients with features such as high-grade tumours, stage >Ta, multifocality, and hydronephrosis with acceptable results. Further research should expand on the different indications for KSS, its postoperative surveillance and comparative economic analyses., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To compare the perioperative outcomes of supine and prone percutaneous nephrolithotomy (PCNL). Methods: A retrospective search of a tertiary medical center database yielded 517 patients who underwent supine ( n = 91) or prone ( n = 426) PCNL between September 2015 and July 2020. Data on demographics, baseline clinical parameters, and stone burden were included as predictors in a logistic regression model, generating a set of propensity scores. Seventy patients after supine PCNL were propensity score-matched 1:1 with patients after prone PCNL and compared for operative time, perioperative complications, system complexity, and stone-free rate. Results: We found that the operative time was significantly shorter in the supine PCNL group than in the prone PCNL group (85.5 ± 25.2 min vs. 96.4 ± 25.8 min, respectively; p = 0.012). The majority of both groups had low-grade (I-II) complexity systems (85.6% and 88.6%, respectively), with no significant difference among all grade groups ( p = 0.749). There were no significant differences between the supine and prone PCNL groups in terms of the overall perioperative complication rate (8.6% vs. 4.3%, respectively; p = 0.301) or stone-free rate (74.3 vs. 65.7%, respectively; p = 0.356), while the rate of blood transfusion was significantly higher in the supine group ( p = 0.023). Conclusions: In our study, we used propensity score matching to compare patients who underwent PCNL in the supine or prone position, adjusting for selection bias. Supine PCNL was associated with a shorter operative time but a higher blood transfusion rate, with no differences in the overall complication and stone-free rates.

Objectives: High-grade nonmuscle-invasive urothelial tumors of the bladder that fail intravesical Bacillus Calmette-Guérin (BCG) immunotherapy are at the highest risk of progression. Initial evidence links heat shock protein expression levels and outcome of bladder cancer after BCG treatment. We aimed to determine the association between HSP60, 70, and 90 expression levels and long-term outcomes of T1 high-grade (T1HG) urothelial bladder tumors treated with BCG immunotherapy., Materials and Methods: Data of 54 consecutive patients with primary T1HG bladder tumors who underwent transurethral resection between 2002 and 2008 and received at least an induction course of BCG were reviewed. Immunohistochemical staining for heat shock protein (HSP)60, 70, and 90 were performed on resected specimens. Study outcomes included disease recurrence and progression. The association between HSP expression levels and outcomes were evaluated with univariable and multivariable Cox proportional hazards models., Results: During a median follow-up of 9.6 years, 25 patients had a disease recurrence and 14 patients a disease progression. Estimated 5-year recurrence and progression-free survival were 59% and 81%, respectively. On multivariable analyses, HSP60 staining >65% was associated with a higher risk for progression (hazard ratio [HR] = 3.96, 95% confidence interval [CI] 1.35-11.58, P = 0.012), and HSP70 staining >5% was associated with a decreased risk for progression (HR = 0.33, 95% CI 0.11-0.98, P = 0.045), and recurrence (HR = 0.29, 95% CI 0.13-0.65, P = 0.003). HSP90 expression was not associated with disease recurrence or progression. Five patients had both a HSP60 staining >65% and a HSP70 staining ≤5% all of whom recurred at a median time of 6 months (interquartile range 3, 16) and 80% of whom progressed at a median time of 26 months (interquartile range 5, 60)., Conclusions: HSP60 and 70 cellular expression levels are associated with long-term outcome following BCG treatment of T1HG urothelial bladder tumors. These findings, if further validated, may be used to better stratify the risk of disease recurrence and progression in this group of patients., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: To determine the accuracy of the surgeon's impression as to the stone-free rate at the end of percutaneous nephrolithotomy (PCNL), and to evaluate predictors for inaccurate estimation., Materials and Methods: A prospective study conducted between 2010 and 2015. Surgeon's impression, categorized as "insignificant residual fragments (RFs)" (<4 mm) or "significant RF" (>4 mm), was recorded at the end of PCNL, and was compared with postoperative imaging results, using CT or a combination of US and kidney, ureter, and bladder radiograph for radiolucent and radio-opaque stones, respectively. The association between missed significant RF and the patient and operative variables was evaluated with univariable and multivariable logistic regression analysis., Results: The study cohort included 312 patients. Significant RFs were found in 75 (24%) patients, comprising all 22 patients in whom RFs were suspected (100%) and 53 patients who were considered stone free (18.6%). The sensitivity, specificity, and positive and negative predictive value of the surgeon's estimation for the absence of significant RFs were 100%, 39%, 0.83, and 1 for radiopaque stones, and 100%, 12.5%, 0.75, and 1 for radiolucent stones. On multivariate analysis, multiple stones (OR = 4, 95% CI: 1.85-8.7, p < 0.001) and cumulative stone size (OR = 1.04, 95% CI: 1.02-1.1, p = 0.005) were independent predictors for missed RFs., Conclusion: In approximately fifth of the patients undergoing PCNL, the surgeon's impression of "insignificant RF" may be inaccurate. Stone size and number were independently associated with higher miss rate. These data should be shared with the patients when the postoperative drainage method and the option for an auxiliary procedure are discussed.

Objective: To present a reliable technique for fluoroscopic controlled, large-bore, ureteral stent placement and exchange in transplant kidneys with persistent ureterovesical strictures., Materials and Methods: We reviewed the medical charts of all patients who underwent kidney transplant with persistent ureterovesical strictures who underwent ureteral stent placement or exchange at our institution between 2005 and 2015 using the new technique. Clinical characteristics and treatment outcomes of the study cohort were analyzed., Results: Ureteral stent insertion or stent exchange, using this technique, was performed in 32 renal transplant units. Median operating time was 24 minutes (interquartile range, 21-36.75 minutes). The overall success rate of the technique at first attempt was 96.9%. In 1 patient, drainage of the transplanted kidney with a nephrostomy tube was indicated after procedure failure. No other local or systemic complications were encountered, and no stent encrustation was noted in this cohort of patients. Renal function remained stable in all patients during a median follow-up of 59 months (interquartile range, 28-61 months)., Conclusion: Herein, we present in detail a step-by-step technique for the insertion and exchange of large-bore ureteral stents in transplanted kidneys. The technique was shown to be safe, effective, and highly successful., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the association between stent dwelling time and sepsis after ureteroscopy, and identify risk factors for sepsis in this setting., Patients and Methods: The prospectively collected database of a single institution was queried for all patients who underwent ureteroscopy for stone extraction between 2010 and 2016. Demographic, clinical, preoperative and operative data were collected. The primary study endpoint was sepsis within 48 h of ureteroscopy. Logistic regressions were performed to identify predictors of post-ureteroscopy sepsis in the ureteroscopy cohort and specifically in patients with prior stent insertion., Results: Between October 2010 and April 2016, 1 256 patients underwent ureteroscopy for stone extraction. Risk factors for sepsis included prior stent placement, female gender and Charlson comorbidity index. A total of 601 patients had a ureteric stent inserted before the operation and were included in the study cohort, in which the median age was 56 years, 90 patients were women (30%), and 97 patients were treated for positive preoperative urine cultures (16.1%). Postoperative sepsis, <48 h after surgery, occurred in eight (1.2%) non-stented patients and in 28 patients (4.7%) with prior stent insertion. Sepsis rates after stent dwelling times of 1, 2, 3 and >3 months were 1, 4.9, 5.5 and 9.2%, respectively. On multivariate analysis, stent dwelling time, stent insertion because of sepsis, and female gender were significantly associated with post-ureteroscopy sepsis in patients with prior stent placement., Conclusions: Patients who undergo ureteroscopy after ureteric stent insertion have a higher risk of postoperative sepsis. Prolonged stent dwelling time, sepsis as an indication for stent insertion, and female gender are independent risk factors. Stent placement should be considered cautiously, and if inserted, ureteroscopy should be performed within 1 month., (© 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.)

Purpose: We determined the ability of urine culture to predict stent culture status and associated infectious pathogens, and evaluated the association between stent culture and post-ureteroscopy sepsis., Materials and Methods: We queried the prospectively collected database at our institution and identified all patients who underwent ureteroscopy between October 2010 and August 2016 who had a ureteral stent before the operation and from whom urine and stent cultures were obtained. The study end point was post-ureteroscopy sepsis within 48 hours of the procedure. We compared urine and stent culture findings, and performed univariate and multivariate analyses to identify predictors of post-ureteroscopy sepsis., Results: The study group comprised 509 patients with a median age of 56 years, of whom 147 (28.9%) were female. Positive urine cultures were found in 91 patients (17.8%) and positive stent cultures were found in 104 (20.4%). Urine and stent cultures were positive in 48 patients (9.4%), of whom only 24 had identical bacteria in both cultures. The most common pathogens isolated from urine and stent cultures were Escherichia coli in 38.5% and Enterococcus in 18.4%. Sepsis developed in 25 patients (4.9%), including 21 (84%) with a positive stent culture and 14 (59%) with a positive urine culture. On multivariate analysis female gender and positive stent culture were significantly associated with post-ureteroscopy sepsis., Conclusions: Only half of the patients with ureteral stents prior to ureteroscopy, and positive stent and urine cultures had similar pathogens in both cultures. Female gender and positive stent culture were associated with a higher risk of post-ureteroscopy sepsis in this population. Stent culture may direct the proper antibiotic treatment in patients with sepsis after ureteroscopy., (Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Background and Purpose: In the era of rigid ureteroscopy (URS) for ureteral stones, asymptomatic renal stones were often left in place. With the advent of flexible URS, however, the treatment of such renal stones became an attractive option. Data are scarce regarding the impact of retrograde intrarenal surgery (RIRS) performed at the time of URS for a symptomatic ureteral stone in comparison with ureteral stone removal alone. The purpose of the study was to compare the outcomes of URS combined with RIRS with URS alone., Patients and Methods: A comparison between patients who underwent URS and RIRS (group A, n=47) and a matched control group of patients undergoing URS alone (group B, n=47) was performed. Matching was based on ureteral stone size and location, and preprocedural Double-J stent placement., Results: The median size of the largest ureteral stone in both groups was 8 mm with a mean total stone burden of 52.9 mm(2) (28.9) and 47 mm(2) (21.1) in groups A and B, respectively. Median renal stone size was 9 mm with a mean total stone burden of 84.1 mm(2) (40.3). Mean surgery time in groups A and B was 68 minutes (19.61) and 39 minutes (15.96), respectively (P<0.001). Median hospital stay was 1 day for both groups. The success rate for ureteral stone removal was 98% and 100% in groups A and B, respectively. Success rate for RIRS was 85% (40/47 cases). Hospitalization length and complications, mainly postoperative fever, did not differ significantly between the groups., Conclusions: Managing asymptomatic renal stones at the time of URS for symptomatic ureteral stones significantly prolongs surgery duration but does not lengthen hospital stay, increase complications, or lower success rates. This combined approach reduces the need for future procedures and is probably more cost effective.

Objective: To evaluate the long-term outcomes and complications of retrograde endoureterotomy for persistent ureterovesical anastomotic strictures in renal transplant patients after percutaneous balloon dilation failure., Methods: From January 2000 to May 2010, 26 (2.6%) of 1004 renal transplant patients developed ureterovesical anastomotic stricture after surgery. Seven of these patients and five additional referred patients with similar characteristics were treated with retrograde endoureterotomy after ≥1 previous unsuccessful attempt at percutaneous balloon dilation. All strictures treated were <1 cm in length. The clinical characteristics and outcomes were analyzed. Success was defined as the absence of symptoms and the resolution of obstruction on imaging after the procedure., Results: The median interval from initial treatment to endoureterotomy was 2.9 months (range 1.3-62.1). Before endoscopic treatment, 8 patients (67%) were treated with a single trial of balloon dilation and 4 (33%) with multiple trials. Endoureterotomy was performed using cold knife, holmium:yttrium-aluminum-garnet laser, and Bugbee electrode in 9, 2, and 1 patients, respectively. The median follow-up period was 44.4 months (range 2.4-68.6). Recurrent stricture developed in 2 patients during a mean follow-up of 4.7 months. Thus, the overall success rate was 83%. Postoperative complications appeared in 3 patients (25%) with culture-positive urinary tract infection. One graft failure occurred but was not related to a recurrent stricture., Conclusion: After failure of antegrade percutaneous balloon dilation, retrograde endoureterotomy is an effective salvage procedure for well-selected cases of renal transplant patients with a short ureterovesical anastomotic stricture., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background and Purpose: Patients who are undergoing laparoscopic ablative therapy (LAT) are often older with more comorbidities in comparison with patients who are undergoing laparoscopic partial nephrectomy (LPN). A matched control study was performed to compare the surgical and functional outcomes of LPN and LAT., Patients and Methods: A prospectively maintained database of 250 patients who underwent nephron-sparing surgery was explored. Fifty-one LAT patients (21 and 30 laparoscopic radiofrequency and cryoablation, respectively) were matched with 51 LPN patients. A comparison of preoperative, operative, and postoperative outcomes was performed., Results: The groups were similar in age, sex, body mass index, preoperative estimated glomerular filtration rate (eGFR), number of comorbidities and tumor size. Patients who were undergoing LAT had a lower incidence of endophytic tumor and higher incidence of upper pole and midpolar tumors. Hilar vessels clamping was performed in LPN (47/51 patients). Mean estimated blood loss and operative time were higher in those undergoing LPN (P<0.01). There was no significant difference in transfusion rate and hospital stay, however. Mean follow-up was 27 and 18 months in LAT and LPN, respectively (P<0.01). The mean percent decline of eGFR at the last follow-up was 10 (95% confidence interval [CI]: 4-15) and 7.5 (95% CI: 4-11), respectively (P<0.43). In comparison with baseline, eGFR declined significantly (P<0. 01), but there was no difference between the groups., Conclusion: Despite renal ischemia, longer operative time, and higher blood loss associated with LPN, the hospital stay and long-term functional outcomes are similar to those of LAT in a matched control study.

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 (P<0.001). New-onset ≥stage III chronic kidney disease developed in only 7% of the patients. Three factors independently predicted POD1 eGFR decline: Artery and vein clamping vs 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.

Objectives: Previously, we described the feasibility of renal hypothermia using microparticulate ice slurry during laparoscopy. In the present study, we compared surface cooling with the ice slurry versus near-frozen saline or warm ischemia (WI) during laparoscopic partial nephrectomy (LPN) in a porcine model., Methods: We used a single-kidney porcine model. Animals in 5 equal groups (n = 6 each) underwent right laparoscopic complete nephrectomy. In Phase I, left LPN was performed under 90 minutes of ischemia and 90-minute renal cooling with either slurry (Slurry group 1) or saline (Saline group 1). No cooling was applied in the WI group. In Phase II, to simulate more extreme condition, ischemia time was extended to 120 minutes and cooling shortened to 10 minutes (Slurry group 2 and Saline group 2). The study endpoints were renal and core temperature during the surgery and serum creatinine at baseline and days 1, 3, 7, and 14 after the procedure., Results: The ice slurry was easily produced and delivered. Nadir renal temperature (mean ± SD) was 8 ± 4 °C in Slurry group 1 vs. 22.5 ± 3 °C in Saline group 1 (P < .0001). Renal rewarming to 30 °C occurred after 61 ± 7 minutes in Slurry group 2 vs. 24 ± 6 minutes in Saline group 2 (P < .0001). Core temperature decreased on average to 35 °C in the Saline groups compared with 37 °C in the Slurry groups (P < .0001). Serum creatinine did not differ between the Saline and Slurry groups in Phases I and II at any time point., Conclusions: Ice slurry provides superior renal cooling compared with near-frozen saline during LPN without associated core hypothermia., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Aim: To compare outcomes in patients treated with laparoscopic partial nephrectomy (LPN) and laparoscopic radical nephrectomy (LRN) for clinical T1bN0M0 renal masses., Materials and Methods: Between 2002 and 2008, 33 and 52 consecutive patients who underwent LPN and LRN, respectively, for clinical stage T1bN0M0 tumors were retrospectively identified from a prospectively maintained database of 450 patients undergoing laparoscopic renal surgery. Perioperative, pathological, and postoperative outcomes were compared., Results: The two groups of patients were similar in age, sex, and body-mass index. Mean radiographic tumor size was smaller (4.8 vs. 5.2 cm, p = 0.04) in the LPN group. Mean operative time (228 vs. 175 minutes, p < 0.0001) and mean estimated blood loss (233 vs. 112 mL, p = 0.003) were higher in the LPN group. Intraoperative complication rates of 15.2% versus 5.7% (p = 0.28) and postoperative complication rates of 24.2% versus 13.5% (p = 0.20) were observed in the LPN and LRN groups, respectively. Overall median follow-up was 15 and 21 months for the LPN and LRN cohorts, respectively. A 12.5% and 29.3% decline in estimated glomerular filtration rate was observed (p = 0.002), and 30.3% compared with 55.7% of patients developed an estimated creatinine clearance (eCrCl) < 60 mL/minutes after treatment (p = 0.04) for LPN and LRN, respectively. There were no differences in pathological stage distribution between the two groups. In the LPN group there were no local or systemic recurrences, and one positive surgical margin was observed. One patient developed metastatic disease in the LRN group., Conclusions: LPN for T1b renal tumors provides superior intermediate-term preservation of renal function compared with LRN. Continued follow-up of these patients is required to evaluate oncological outcomes.

Study Type: Therapy (case series) Level of Evidence 4., Objective: To investigate the outcomes of laparoscopic partial nephrectomy (LPN) for endophytic tumours and those located near the hilum or the posterior upper-pole, as these pose a technical challenge., Patients and Methods: Technically challenging tumours were defined as endophytic, hilar, or at the posterior upper-pole (group 1), and were compared to tumours in other locations (group 2). We collected data prospectively for all patients undergoing LPN at our institution, including baseline patient and tumour characteristics, surgical and postoperative outcomes. Two-sided t-test or rank-sum test, and chi-square or exact tests were used as appropriate for comparison of continuous and categorical variables, respectively, with P < 0.05 considered to indicate statistical significance., Results: There were 184 patients treated with LPN (42 in group 1 and 142 in group 2) between 2002 and 2008 by one surgeon (A.L.S.). Groups 1 and 2 were similar in terms of baseline variables (age, sex, body mass index, comorbidities, previous surgery, renal function and haematocrit) and in tumour size. LPN for challenging tumours resulted in a higher rate of collecting system repair (78% in group 1, 61% in group 2, P = 0.03). However, operative (surgery time, warm ischaemia time, blood loss, intraoperative complications) and postoperative outcomes (renal function, nadir haematocrit, complication rate, hospital stay and positive margin rate) were similar between the groups., Conclusions: With developing experience LPN can be safe for technically challenging renal tumours in well selected patients.

Background and Purpose: The Rotablator is an angioplasty device that is passed over a wire. It uses a high-speed rotational "burr" (2 mm in diameter) that is coated with microscopic diamond particles and cooled by saline. It rotates at high speed (approximately 200,000 rpm) breaking up endovascular blockage into minute (smaller than red blood cells) fragments. We investigated, in vitro and ex vivo, the possible use of the Rotablator for urinary stone disease., Materials and Methods: Human stones of different sizes and composition were used for the experiment. Stone impaction in vitro was modeled by wedging the stones into the proximal part of a 16F silicone Foley catheter. Likewise, an ex-vivo study was performed on stones placed into a freshly harvested swine ureter using a nitinol basket. Data regarding the drill time, remaining stone size, and ureteral damage were collected., Results: Overall, 15 stones were treated (10 in vitro and 5 ex vivo). The device successfully drilled through all the stones, along the path of the guidewire, allowing complete passage of the burr. The pretreatment mean stone size for the silicone and ureteral testing was 65 mm(3) and 34 mm(3), respectively (both P < 0.01). The post-treatment size was 54 mm(3) and 24 mm(3), respectively. Average treatment time was 100 seconds. No visual macroscopic ureteral damage or perforation was observed., Conclusions: In vitro, the Rotablator is capable of drilling through stones with minimal damage. Drilling, however, occurred alongside the stone in which the guidewire was located and, thus, stone fragmentation appears to be minimal. Further studies are necessary to investigate other burr configurations and the use of the Rotablator for the fluoroscopic-guided passage of ureteral impaction in difficult clinical settings.

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.

Objective: The objective of this study was to compare the outcomes of patients >or=70 years of age undergoing laparoscopic partial nephrectomy (LPN), laparoscopic radical nephrectomy (LRN), and laparoscopic ablative techniques (LAT) for small renal masses., Methods: From a prospectively maintained database we identified 19 (LRN), 28 (LPN), and 19 (LAT) patients aged >or=70 who underwent surgery for cT1aN0M0 lesions. Perioperative, surgical, and functional outcomes were compared., Results: The three groups were similar in age, race, body mass index, and estimated creatinine clearance. In the LRN group, mean tumor diameter was larger (3.3 vs. 2.4 cm [LPN] and 2.7 cm [LAT]; p = 0.0005) and there was a higher percentage of central tumors (73.7% vs. 25.0% and 5.3%; p < 0.0005) when compared with the LPN and LAT groups, respectively. Although intraoperative and postoperative complication rates were similar, mean estimated blood loss and operative time were highest in the LPN group (p < 0.05). Moreover, 42.1%, 39.3%, and 42.1% of patients had preoperative stage 3 chronic kidney disease in the LRN, LPN, and LAT groups, respectively. Patients who underwent LRN had a lower follow-up estimated creatinine clearance (43.4 vs. 61.4 mL/min [LPN] and 59.2 [LAT]; p < 0.01) and a higher likelihood of developing stage 3 chronic kidney disease after treatment (100% vs. 25.0% [LPN] vs. 18.2 [LAT]; p < 0.0005)., Conclusions: Impaired renal function is common in elderly patients presenting with renal masses. LPN and LAT provide superior preservation of renal function when compared with LRN in this population. In appropriately selected patients >or=70 years of age presenting with T1a renal lesions, laparoscopic nephron-sparing approaches should be considered.

Objectives: To review our laparoscopic partial nephrectomy (LPN) experience, examine the evolution of technique, and compare the outcomes between the early and recent experience. The indications and surgical technique of LPN continuously evolve., Methods: Data for 184 patients who underwent LPN for a tumor between October 2002 and August 2008 was retrieved from a prospective database. Surgical and functional outcomes for the entire cohort were analyzed and the first 50 (group 1) and most recent 50 (group 2) cases were compared., Results: The groups were similar in terms of baseline renal function, body mass index, and comorbidities. The mean tumor size and the proportion of central tumors in groups 1 and 2 were 2.4 vs 3 cm and 12% vs 52%, respectively (P <.003). In group 2 we stopped the use of ureteral catheters and bolster renorrhaphy, and routinely clamped the renal hilum. Mean warm ischemia time in groups 1 and 2 (30 and 27 minute, respectively, P = .3) and the complication rate were similar. Overall, patients with tumors >4 cm had more complications (P = .042). In group 2 the estimated blood loss and hospital stay decreased (243 vs 140 mL, P = .01, 1.4 vs 2.5 days, P <.001). Overall 78% of the tumors were malignant and the positive margin rate was 3%. With a median follow-up of 18 months, no local or distant tumor recurrences were observed., Conclusions: With growing experience and technical modifications, LPN is now performed for patients with larger and more central tumors. Longer follow-up is necessary to evaluate oncologic outcomes., (2010 Elsevier Inc. All rights reserved.)

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 pT(2) or pT(3) 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.

Purpose: We assessed the long-term outcome of laser endoureterotomy for benign ureteral stricture., Materials and Methods: From a database of 69 patients who underwent retrograde laser endoureterotomy from October 2001 to June 2007 we identified 35 with a benign ureteral stricture. Clinical characteristics, operative results and functional outcomes were investigated. Success was defined as symptomatic improvement and radiographic resolution of obstruction., Results: Median followup was 27 months (range 10 to 72). All except 1 patient were followed at least 16 months. All patients completed clinical followup and 33 completed imaging. Of 35 patients 29 (82%) were symptom-free during followup and 26 of 33 (78.7%) were free of radiographic evidence of obstruction. All except 1 failure occurred within less than 9 months postoperatively. The success rate was higher for nonischemic strictures (100% vs 64.7%, p = 0.027) and tended to be higher for strictures 1 cm or less (89.4% vs 64.2%, p = 0.109)., Conclusions: Holmium laser endoureterotomy is effective for benign ureteral stricture in well selected patients. Most failures occur within less than 9 months after surgery, which may indicate a need for closer followup during postoperative year 1. Factors that might may outcome are ischemia and stricture length.

Objective: Repair of renal collecting system (CS) during laparoscopic partial nephrectomy (LPN) requires advanced skills and nevertheless prolongs renal ischemia time. We assessed tumor parameters that may predict CS transection and thus improve preoperative planning., Methods: Data were prospectively collected for 184 consecutive LPN cases performed at our institution between 2002 and 2008 by a single senior surgeon. Twelve patients were excluded because of open conversion and seven because of missing data. Among the rest (n = 165), CS was transected in 115 (61%). Tumor parameters (radiographic appearance-solid vs. cystic, size, polar location, and depth) were evaluated with univariate and multivariate logistic regression analysis. Classification and Regression Tree analysis was applied to define the optimal cutoff for tumor size., Results: In univariate analysis, tumor size (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.8, 4.3; p < 0.0001) and tumor appearance (solid: OR 2.1, 95% CI 1.1, 4.3) achieved statistical significance, while tumor depth (endophytic: OR 3.1, 95% CI 0.8, 11.0; p = 0.08) trended toward significance. In multivariate analysis, size (p < 0.0001) and solid tumor appearance (p = 0.006) were independent predictors. In Classification and Regression Tree analysis, 2.5 cm was found to be the optimal cutoff for the tumor size., Conclusions: The odds of CS transection during LPN triple with each additional centimeter in tumor size, are 10-fold higher for tumors >2.5 cm, and are almost twice higher for solid tumors, compared with cystic. These findings may be useful in LPN planning.

Purpose: 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., Materials and Methods: 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., Results: 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., Conclusions: 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.

Introduction: Closure of the urinary collecting system and renal parenchyma is a technically challenging aspect of laparoscopic nephron-sparing surgery and an obstacle to its more widespread use. A novel barbed polydioxanone suture material Quill self-retaining suture (SRS) (Angiotech Pharmaceuticals) has been introduced for knot-free tissue approximation. We compared the outcomes of Quill SRS versus a conventional technique for kidney and collecting system closure during laparoscopic porcine partial nephrectomy., Methods: After approval of the Institutional Animal Care and Use Committee, 10 female pigs underwent bilateral transperitoneal laparoscopic lower pole heminephrectomy. Closure of the collecting system and approximation of the renal parenchyma was performed in two layers using continuous knotless barbed suture for one kidney (Quill SRS) and polyglactin (Vicryl) with absorbable polydioxanone clips (LapraTy; Ethicon) on the contralateral kidney. For both techniques, the collecting system was closed with 2-0 suture and renal parenchyma with #1 suture. Warm ischemia and suturing time were recorded, and resected tissue was weighed. All animals were sacrificed 1 week after surgery. Serum hemoglobin and visual inspection at necropsy were used to assess for bleeding; visual inspection of the peritoneum and bilateral retrograde pyelography were used to assess for urinary fistula., Results: Mean (+/-standard deviation [SD]) weight of resected tissue (barbed, 34 +/- 13 g; clips, 34 +/- 11 g; p = 0.6), mean (+/-SD) ischemia time (barbed, 34 +/- 8 minutes; clips, 34 +/- 10 minutes; p = 0.7), and mean (+/-SD) suturing time (barbed, 21 +/- 4 minutes; clips, 22 +/- 7 minutes; p = 0.7) were similar between groups. No animal had a visible hematoma or urinoma at necropsy. On retrograde pyelography, a small urinary leak was found in two kidneys in each group (p = 0.6)., Conclusions: In a porcine laparoscopic partial nephrectomy model, it appears that knotless barbed suture is as effective, efficient, and safe as a conventional technique. Further evaluation in humans is warranted and required.

Purpose: 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., Materials and Methods: 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., Results: 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)., Conclusions: 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.

The internal diameter of the ureteral access sheath limits the size of stones that can be removed during flexible ureteroscopy. We describe a technique that allows removal of larger stones, which are entrapped and removed en bloc with the access sheath. This new technique was shown to be efficient and safe.

Background and Purpose: Adult stone patients are treated with several thousand lithotripter shockwaves (SWs) in order to pulverize a kidney stone. This typical clinical dose assures that the stone will be fractured completely. However, this same dose induces damage to the kidney, especially pediatric-size kidneys. If increasing SW number is known to increase renal injury and functional impairment, will reducing SW number below typical treatment levels significantly decrease kidney damage and hemodynamic changes?, Materials and Methods: To address this question, one kidney in each of nine juvenile pigs (6-7 weeks old) was treated with 1000 SWs at 24 kV directed at a lower-pole calix with an unmodified HM-3 lithotripter. Parenchymal-lesion size was determined by sectioning the entire kidney and quantitating the amount of hemorrhage in each slice. Renal function was determined before and after SW treatment by inulin clearance, paraaminohippurate (PAH) extraction, and PAH clearance. The resulting morphologic and functional changes were then compared with those of kidneys that had been treated with a typical clinical dose of 2000 SWs (data previously published; J Am Soc Nephrol 2000;11:310). Eleven pigs were utilized as sham-treated controls., Results: Limiting SW number to 1000 significantly reduced the size of the lesion (by 95%) and reduced the degree of functional change (glomerular filtration rate by 38%, PAH extraction by 73%, renal plasma flow by 46%) compared with kidneys receiving 2000 SWs (an adult dose)., Conclusions: These data support the idea that SW number should be reduced to the lowest number that fractures kidney stones in order to minimize renal injury and functional impairment.

Background and Purpose: Retrograde intrarenal surgery (RIRS) is a recent addition to the treatment options for renal calculi. Therefore, the indications, as well as the predictors of success, are still being studied. Herein, we report a retrospective comparison of RIRS performed as the primary treatment and as second-line therapy, mostly after shockwave lithotripsy (SWL) failure., Patients and Methods: Between October 2001 and August 2004, 93 patients underwent RIRS (11% of all ureteroscopies), all by the same surgeon. Patients were divided into two groups: group 1 (n = 42) consisted of patients undergoing RIRS as a first-line modality and group 2 (n = 51) of those having RIRS as secondline therapy. The indications for RIRS in group 1 were renal calculi with prior placement of a double-J stent (30%), renal + ureteral stone (25%), pushback of ureteral stone during ureteroscopy (22%), a radiolucent stone (8%), coagulopathy, and abnormal renal anatomy. In group 2, the patients were initially treated by SWL (92%) or percutaneous nephrolithotomy. The groups did not differ significantly in demographic characteristics, mean stone size (9.5 and 8.7 mm, respectively), or stone location (in both 60% in the lower pole). The variables analyzed were operating time, complications, length of hospitalization, and stone-free rate., Results: The overall stone-free rate was 73%. However, the stone-free rate was significantly higher in group 1 than in group 2: 80% v 67%, respectively. A higher complication rate and longer hospitalization were noted in group 2, although the difference was not statistically significant., Conclusions: When RIRS is performed after failed SWL, it has a lower success rate and may be associated with a higher morbidity rate than if it is performed as first-line therapy. These results suggest that the success rate of RIRS may be influenced by the same negative factors that reduce SWL success. Therefore, if a patient fails SWL, careful consideration should be given to the best second-line therapy comparing RIRS with percutaneous stone removal.

Purpose: PNL via an UP puncture is efficient for treating complex stone disease. Access via the UP can provide better visualization, allowing greater stone clearance with a rigid instrument due to its more favorable alignment with the axis of the intrarenal collecting system. However, the presence of a NT through the upper pole tract, especially with a supracostal puncture, can generate significant patient discomfort. We reviewed our experience with a technique using tubeless UP access for PNL with concomitant placement of a NT via a LP calix., Materials and Methods: We performed a retrospective review of our experience using tubeless UP access for PNL with concomitant placement of an LP NT for postoperative drainage. Patient demographics, the number and location of accesses, stone size, stone-free rates, concurrent/additional procedures and complications were recorded., Results: A total of 63 tubeless UP accesses were performed in 62 patients undergoing PNL, including unilateral access in 61 and bilateral access in 1. Supracostal UP punctures were used in 58 patients, including 40 above the 12th, 17 above the 11th and 1 above the 10th rib. Each patient underwent at least 2 accesses and 3 had 3 or more accesses placed. LP access was nondilated in 37 patients and dilated in 26. Of the patients 56.6% were stone-free after a single procedure, increasing to 96.2% following secondary procedures. Three of the 62 patients (4.8%) required transfusion, 3 (4.8%) required intervention for pleural morbidity and 1 (1.6%) required a stent for a nonsealing upper pole access., Conclusions: Tubeless UP access provides maximal efficiency for stone clearance during PNL, while minimizing the morbidity of an intercostal tube.

Objectives: To evaluate the correlation between preoperative urine culture (UC) and intraoperative stone culture (SC) and the impact of SC findings on clinical decisions., Methods: UC and intraoperative fragmented SC were prospectively obtained in all patients undergoing percutaneous nephrolithotomy between January 2004 and March 2005. Patients with a positive UC received a full course of antibiotics before surgery. All postoperative systemic inflammatory response syndrome (SIRS) events were recorded, as was the antibiotic regimen used and any changes in antibiotic treatment secondary to the SC results., Results: The study group consisted of 75 consecutive patients. Of these 75 patients, 33 (49%) had sterile UC and SC results. Both urine and renal stones were colonized in 17 patients (24%); in 6 of them, the UC and SC showed different pathogens. A colonized SC associated with a sterile UC was found in 19 patients (25%). The calculated UC sensitivity, specificity, and positive and negative predictive value for the detection of stone colonization was 30%, 94%, and 84% and 58%, respectively. Seventeen patients (22%) had postoperative SIRS. In 13 of them, a change in antibiotic treatment was made according to the SC findings. On univariate analysis, the incidence of SIRS was not related to the length of the operation, stone-free rate, or supracostal or infracostal access. The relative risk of SIRS when the SC was positive was 3.6., Conclusions: Renal calculi pathogens are one of the predisposing factors for infectious events; however, preoperative UC often fails to grow stone-colonizing bacteria. Intraoperative SC may be essential in directing the antibiotic regimen postoperatively and should be routinely used.

Artificial stones are used in research on the mechanisms of stone breakage in shock wave lithotripsy (SWL) and in assessing lithotripter performance. We have adopted Ultracal-30 gypsum as a model, finding it suitable for SWL studies in vitro, acute animal experiments in which stones are implanted in the kidney, and as a target to compare the in vitro performance of intracorporeal lithotripters. Here we describe the preparation of U-30 stones, their material properties, shock wave (SW) breakage characteristics, and methods used for quantitation of stone fragmentation with this model. Ultracal-30 gypsum cement was mixed 1:1 with water, cast in plastic multi-well plates, then, the stones were liberated by dissolving the plastic with chloroform and stored under water. Stone breakage in SWL was assessed by several methods including measures of the increase in projected surface area of SW-treated stones. Breakage of hydrated stones showed a linear increase in fragment area with increased SW-number and SW-voltage. Stones stored in water for an extended time showed reduced fragility. Dried stones could be rehydrated so that breakage was not different from stones that had never been dry, but stones rehydrated for less than 96 h showed increased fragility to SWs. The physical properties of U-30 stones place them in the range reported for natural stones. U-30 stones in vitro and in vivo showed equivalent response to SW-rate, with approximately 200% greater fragmentation at 30 SW/min compared to 120 SW/min, suggesting that the mechanisms of SW action are similar under both conditions. U-30 stones provide a convenient, reproducible model for SWL research.

Background and Purpose: Open stone surgery nowdays is rare. However, some patients who are treated today have in the past undergone open nephrolithotomy. The aim of this study was to determine the possible impact of open nephrolithotomy on the efficacy and morbidity of subsequent percutaneous nephrolithotomy (PCNL)., Patients and Methods: We reviewed the files of all 167 patients undergoing PCNL at our institution between December 2000 and December 2003. The same surgeon performed all of the procedures. We compared 21 patients undergoing PCNL after open nephrolithotomy to the same kidney with all other patients undergoing PCNL. The groups did not differ in terms of age or stone burden (mean size, number of stones, percentage with staghorn calculi). The outcomes measured were operating time, necessity for secondary procedures, stonefree rate, and intraoperative and postoperative complications., Results: The operating time (203+/-92 v 177+/-52 minutes) and percentage of secondary procedures (29% v 12%) were significantly higher in patients who had previously undergone open stone surgery. However, the stone-free rate (95% v 93%), intraoperative complication rate (10% v 9%), and postoperative complication rate (10% v 11%) did not differ significantly., Conclusions: A PCNL in a patient with a history of open nephrolithotomy may take longer and lead to a higher percentage of auxiliary procedures, probably because of scar tissue and anatomic changes in the kidney. However, the morbidity and efficacy of PCNL appear to remain the same in these patients.

Purpose: Conservative treatment of upper urinary tract tumors has been popularized during the last decade. Like in bladder cancer management, localized adjuvant therapy has been advocated to reduce the risk of disease recurrence or progression. In this study we tested the feasibility of creating vesicoureteral reflux (VUR) using a Double-J stent (Medical Engineering Corp., New York, New York) as a measure of efficacy for intravesical adjuvant treatment of the ureter and renal collecting system., Materials and Methods: The cohort included 100 consecutive patients in whom a Double-J stent was inserted for renal obstruction. All the patients underwent cystography in the supine position by retrograde filling of the bladder with a 50% dilute solution of 300 mgI/ml iopromide in serial increments of 50 ml up to a maximum of 350 ml. A total of 41 patients underwent cystography immediately following stent insertion (early group) and 59 patients with indwelling stents underwent cystography before further endourological intervention (late group). The presence of VUR and the level along the ureter and renal collecting system were assessed fluoroscopically., Results: Overall VUR was detected in 56 patients (56%), specifically 11 of the 41 (27%) in the early group and 45 of the 59 (76%) in the late group (p <0.001). There was no correlation between stent diameter or length and VUR, or between patient sex, age or particular side and the likelihood of reflux. Mean minimal intravesical volume required to obtain reflux was 171 +/- 11 ml, which was significantly higher in the early (255 +/- 21 ml) than in the late (146 +/- 11 ml) cystogram group. In 24 of the 56 patients (43%) with VUR, there was complete visualization of the entire ureter and renal collecting system. However, 15 patients (26%) had opacified renal pelves and calices without concomitant visualization of the ureters, whereas 7 patients (31%) had reflux to the ureter without opacification of the renal pelvis., Conclusions: VUR is not a guaranteed consequence of Double-J stent placement. Therefore, when upper urinary tract instillation with the Double-J technique is considered, a cystogram should be performed first to confirm the occurrence of reflux, determine the intravesical volume required to induce reflux and ascertain that the pertinent section of the ureter or pelvicaliceal system from which the tumor was initially removed is opacified during study. An interval that remains to be defined should be allowed between stent insertion and VUR assessment.

Background and Purpose: Ultrasonic lithotripsy was one of the first modalities used for treating renal and ureteral stones. However, in recent years, it has been largely replaced by newer techniques such as laser lithotripsy with rigid as well as flexible ureteroscopes. The aim of this study was to review the results and our current indications for ureteroscopic ultrasonic lithotripsy (UUL)., Patients and Methods: Between October 2000 and May 2002, 340 ureteroscopies were performed for the treatment of ureteral stones in the Rabin Medical Center. Of this series, 9 patients (2.6%) underwent UUL using a semirigid 8F ureteroscope (Wolf) and an Olympus ultrasonic lithotripter (LUS-1) with a 4.5F hollow probe. Four patients had Steinstrasse following shockwave lithotripsy, four had large (1-2-mm) ureteral stones, and one had an impacted calcified ureteral double-J stent. Stones >5 mm were initially fragmented by the holmium laser (550-microm fiber). A double-J stent was placed in all patients. The mean follow-up time was 20 months., Results: The mean operative time was 84 minutes. No intraoperative complications occurred. The mean hospital stay was 3.9 days. Eight patients became stone free after the first procedure, and the other underwent secondary ureteroscopy, which rendered him stone free., Conclusions: Patients in whom UUL is performed are relatively complex stone patients. The use of ultrasonic lithotripsy following, or in combination with, laser or ballistic devices utilizes the unique properties of UUL, which combines stone fragmentation and efficient removal of small fragments. The technique was particularly useful in patients with Steinstrasse or a large stone burden. Thus, UUL has a limited but significant role in the treatment of ureteral stones.

While shock wave lithotripsy (SWL) is known to cause significant damage to the kidney, little is known about the initial injury to cells along the nephron. In this study, one kidney in each of six juvenile pigs (6-7 weeks old) was treated with 1,000 shock waves (at 24 kV) directed at a lower pole calyx with an unmodified HM-3 lithotripter. Three pigs were utilized as sham-controls. Kidneys were fixed by vascular perfusion immediately after SWL or sham-SWL. Three of the treated kidneys were used to quantitate lesion size. Cortical and medullary samples for light (LM) and transmission electron microscopy (TEM) were taken from the focal zone for the shock waves (F2), the contralateral kidney, and the kidneys of sham-SWL pigs. Because preservation of the tissue occurred within minutes of SWL, the initial injury caused by the shock waves could be separated from secondary changes. No tissue damage was observed in contralateral sham-SWL kidneys, but treated kidneys showed signs of injury, with a lesion of 0.2% +/- 0.1% of renal volume. Intraparenchymal hemorrhage and injury to tubules was found at F2 in both the cortex and medulla of SWL-treated kidneys. Tubular injury was always associated with intraparenchymal bleeding, and the range of tissue injury included total destruction of tubules, focal cellular fragmentation, necrosis, cell vacuolization, and membrane blebbing. The initial injury caused by SWL was cellular fragmentation and necrosis. Cellular vacuolization, membrane blebbing, and disorganization of apical brush borders appear to be secondary changes related to hypoxia., (Copyright 2003 Wiley-Liss, Inc.)

Renal blood flow falls in both kidneys following delivery of a clinical dose of shockwaves (SW) (2000 SW, 24 kV, Dornier HM3) to only one kidney. The role of renal nerves in this response was examined in a porcine model of renal denervation. Six-week-old pigs underwent unilateral renal denervation. Nerves along the renal artery of one kidney were identified, sectioned and painted with 10% phenol. Two weeks later the pigs were anesthetized and baseline renal function was determined using inulin and PAH clearances. Animals then had either sham-shockwave lithotripsy (SWL) (group 1), SWL to the innervated kidney (group 2) or SWL to the denervated kidney (group 3). Bilateral renal function was again measured 1 and 4 h after SWL. Both kidneys were then removed for analysis of norepinephrine content to validate the denervation. Renal plasma (RPF) flow was significantly reduced in shocked innervated kidneys (group 2) and shocked denervated kidneys (group 3). RPF was not reduced in the unshocked denervated kidneys of group 2. These observations suggest that renal nerves play a pivotal role in modulating the vascular response of the contralateral unshocked kidney to SWL, but only a partial role, if any, in modulating that response in the shocked kidney., (Copyright 2003 S. Karger AG, Basel)

Purpose: 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., Materials and Methods: 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., Results: 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., Conclusions: 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.

Purpose: The current trend toward ungated shock wave lithotripsy means that more patients are being treated with shock waves delivered at a rapid rate (120 shock waves per minute or greater). However, no benefit of an increased shock wave rate has been shown and in vitro studies indicate that slowing the shock wave rate actually improves stone fragmentation. We tested the effect of the shock wave rate on stone comminution in a new animal model., Materials and Methods: Gypsum model stones were inserted via upper pole percutaneous access into the lower pole calix of the kidneys of female pigs weighing approximately 100 pounds. Shock wave lithotripsy was performed (400 shock waves uninterrupted at 20 kV. and 30 or 120 shock waves per minute) 2 hours later using an unmodified HM3 lithotriptor (Dornier Medical Systems, Marietta, Georgia). After en bloc excision of the urinary tract stone fragments were collected and sieved through 2 mm. mesh. The particles were weighed and surface area was determined., Results: Stones treated at 30 shock waves per minute broke more completely than stones treated at 120 shock waves per minute. The percent of fragments greater than 2 mm. was significantly higher for stones treated at the fast rate of 120 versus the slow rate of 30 shock waves per minute (mean +/- SEM 81% +/- 14% versus 45% +/- 12%, p <0.005). When stone fragmentation was expressed as the percent increase in fragment surface area, significantly greater fragmentation occurred at the slower than at the more rapid rate (327% +/- 63% versus 135% +/- 136%, p <0.02)., Conclusions: Slowing the rate of shock wave administration during shock wave lithotripsy significantly improves the efficiency of stone fragmentation in vivo.

Shock wave lithotripsy (ESWL) remains the most common treatment for renal calculi. In this article, recent literature pertaining to ESWL monotherapy of renal calculi was reviewed, with the goal of improving ESWL results through better case selection. When selecting the optimal surgical approach for a patient, multiple factors must be considered. Factors to consider include stone-related factors (size, number, composition and location), renal anatomical factors, and patient-related factors. Each of these factors is presented in detail, with the discussion limit to non-staghorn renal calculi. Children, the elderly, patients with hypertension, and patients with impaired renal function, may be at increased risk of ESWL complications and adverse effects and care should be taken to limit the number and energy of shock waves applied in these special cases. Absolute contraindications to ESWL remain pregnancy, distal obstruction, untreated infection, and uncorrected coagulopathy.

Purpose: To determine the safety and feasibility of Endoloop-assisted laparoscopic partial nephrectomy in a large-animal model., Materials and Methods: Twelve female Yucatan mini-pigs underwent either left (N = 6) or right (N = 6) transperitoneal laparoscopic lower-pole nephrectomy following cinching of a 1-0 Vicryl suture loop (Endoloop) proximal to the resected lower pole until ischemic discoloration was achieved. The ischemic lower pole was excised with Endo-scissors and the lower pole removed using a laparoscopic bag. Follow-up involved evaluation under anesthesia with retrograde pyelography and intravenous urography and subsequent sacrifice for pathologic evaluation at 3 (N = 4), 14 (N = 4), or 60 (N = 4) days., Results: All procedures were completed successfully. In two cases, the Endoloop slipped off the retained parenchyma. Both problems were corrected immediately with no sequelae. At sacrifice, all upper-pole renal segments functioned, as shown by urography, and no urinomas or abscesses were found. In one animal, there was moderate hydronephrosis presumably secondary to ureteral scarring, and in another, mild extravasation was demonstrated on the retrograde pyelogram., Conclusion: We were able to perform laparoscopic partial nephrectomy with the Endoloop safely and effectively in the current model. Modification of the Endoloop to allow more controlled pressure application may allow clinical application of this method for polar laparoscopic partial nephrectomy.

Background and Purpose: Renal colic in pregnancy presents a diagnostic and therapeutic challenge. When conservative therapy fails or is not indicated, temporary measures such as ureteral stenting are often chosen as a first-line intervention, postponing definitive management until after delivery. We propose that advances in endoscopic equipment and anesthesia techniques dictate a more definitive strategy., Patients and Methods: A retrospective analysis was performed on 10 consecutive pregnant patients presenting with renal colic necessitating intervention between April 1998 and April 2000. The mean patient age was 23 (range 17-31) years. One patient presented during the first trimester, six in the second, and three in the third. Four of the patients had a history of stone disease. All patients had flank pain at presentation, six on the left side and four on the right. Hematuria, fever, and nausea were present in eight, one and two patients, respectively., Results: Ultrasound scanning was performed in all patients and showed a low sensitivity (28.5%) when compared with intraoperative findings. Ureteroscopy (rigid and/or flexible) was performed as a first-line intervention in six patients, in two of whom no stone was found. Percutaneous nephrolithotomy was carried out in one patient presenting with a nephrostomy tube. Double-J stents were placed in only three patients with specific indications, namely urinary infection, late gestational phase, and difficult ureteroscopy secondary to a narrow ureter. No obstetric or urologic complications were noted. The mean size of the stones retrieved in seven patients was 7 mm., Conclusions: Ureteroscopy may be considered a safe and effective first-line definitive therapeutic option in pregnant patients requiring intervention for stone disease.

Background and Purpose: Conical blunt trocar insertion may eliminate the need for fascial closure (FC) in transperitoneal laparoscopic renal surgery. This concept applies to 12-mm blunt trocar placement through muscular parts of the abdominal wall, relying on muscle splitting and eventual muscle retraction when the trocar is removed. We retrospectively assessed the safety of fascial nonclosure (FNC) after 12-mm blunt port insertion., Patients and Methods: Ninety transperitoneal laparoscopic renal procedures were performed between August 1999 and May 2000. Four ports (two 12 mm and two 5 mm) were usually used except for 30 donor nephrectomies, where an additional 5-mm port was used. The 12-mm trocars were inserted at the lateral border of the rectus muscle 5 cm below the costal margin and in the anterior axillary line 8 cm below the costal margin. Fascial closure was performed in 62 patients and nonclosure in 28 patients. Exclusion criteria for FNC included midline location, malnutrition, renal failure, and chronic use of steroids. Postoperative outcomes were compared in 20 patients with FNC matched with 20 patients with FC., Results: At an average of 4.8 months of follow-up, none of the patients developed a trocar site hernia. No significant statistical differences were observed between the groups with regard to intraoperative and postoperative data., Conclusions: These two approaches appear to be equivalent in terms of patient morbidity and postoperative hospital stay. Fascial nonclosure after transperitoneal 12-mm blunt trocar insertion, through muscular parts of the abdominal wall may be safe and efficacious and eliminates the last step in transperitoneal laparoscopic renal surgery.

Purpose: Retrograde ureteral stenting is often considered the first line option for relieving ureteral obstruction when temporary drainage is indicated. Several retrospective studies have implied that in cases of extrinsic obstruction retrograde ureteral stenting may fail and, therefore, percutaneous nephrostomy drainage is required. We examined the efficacy of retrograde ureteral stenting for resolving ureteral obstruction and identified clinical and radiological parameters predicting failure., Materials and Methods: Enrolled in our prospective study were 92 consecutive patients with ureteral obstruction, which was bilateral in 8. Retrograde ureteral stenting was attempted in all cases by the urologist on call. When stent insertion failed, drainage was achieved by percutaneous nephrostomy. Patients were followed at 3-week intervals for 3 months. Each followup visit included a medical interview, blood evaluation, urine culture and ultrasound. Stent malfunction was defined as continuous flank pain manifesting as recurrent episodes of acute renal colic, 1 or more episodes of pyelonephritis, persistent hydronephrosis or elevated creatinine. Preoperative data and outcomes were compared in cases of intrinsic and extrinsic obstruction. Univariate and multivariate analysis was done to identify predictors of the failure of ureteral stent insertion and long-term function., Results: The etiology of obstruction was intrinsic in 61% of patients and extrinsic in 39%. Extrinsic obstruction, which was associated with a greater degree of hydronephrosis, was located more distal. Retrograde ureteral stenting was successful in 94% and 73% of patients with intrinsic and extrinsic obstruction, respectively. At the 3-month followup stent function was maintained in all patients with intrinsic obstruction but in only 56.4% with extrinsic obstruction. On multivariate logistic regression the type of obstruction, level of obstruction and degree of hydronephrosis were the only predictors of stent function at 3 months. Stent diameter and preoperative creatinine had no predictive value., Conclusions: Retrograde ureteral stenting is a good solution for most acutely obstructed ureters. In patients with extrinsic ureteral obstruction a more distal level of obstruction and higher degree of hydronephrosis are associated with a greater likelihood of stent failure. These patients may be better served by percutaneous drainage.

Background and Purpose: The ideal replacement for bladder tissue is yet to be described, although multiple alternatives have been studied. Currently, enterocystoplasty, despite its limitations, is considered the gold standard for bladder augmentation. This study evaluated the feasibility, safety, and morbidity of laparoscopic ileocystoplasty in a large-animal model., Materials and Methods: In eight minipigs, laparoscopy was performed using four ports. A segment of ileum was delivered through a 3-cm umbilical incision and detubularized and refashioned using standard open surgical technique. Laparoscopic hemicystectomy was then performed, followed by laparoscopic suturing of the ileal patch to the bladder. The bladder was drained with a Foley catheter, but no pelvic drain was placed. All animals were followed for for a minimum of 3 months. Preoperative and postoperative evaluation included measurement of bladder capacity, ultrasound imaging of the kidneys, blood counts, and serum electrolyte and creatinine measurements. Two of the animals were sacrificed at 3 months and one at 6 months, and the bladders were harvested., Results: Eight animals underwent ileocystoplasty without intraoperative or postoperative complications. The average operating and anastomosis time was 250 minutes and 96 minutes, respectively. All animals had normal preoperative blood values that remained normal during follow-up. Bladder capacity decreased initially to 71% of the baseline volume and then increased to 83% and 117% at 3 and 6 months. One of three animals sacrificed was noted to have a right midureteral stricture., Conclusions: We developed a reliable laparoscopic technique for ileocystoplasty that may extend the advantages of laparoscopy, including better cosmesis and reduced risk of postoperative adhesions, to bladder augmentation.

Background and Purpose: Bacterial colonization of indwelling ureteral stents may serve as a nidus for bacteriuria in operations where stents are manipulated. The predictive value of urine cultures in the assessment of stent colonization was examined in 65 patients with indwelling ureteral stents., Patients and Methods: Prophylactic antibiotic treatment was administered prior to stent insertion. All patients were ambulatory at the time of investigation and were examined in the outpatient clinic. Urine cultures were taken prior to stent removal after 8 to 150 (mean 64) days. The stents were removed under aseptic conditions, and the proximal and distal ends were cut off and placed in a culture medium for evaluation. None of the patients was treated for urinary tract infection prior to stent removal., Results: Bacteriuria was found in 15% of the patients. In 35 patients (54%), urine and stent cultures were sterile. In 20 patients (31%), the urine culture was sterile but the stent was colonized (Enterococcus 9, E. coli 5, Staphylococcus aureus 2, S. epidermidis 2, Candida 1, Citrobacter diversus 1). One patient had a sterile stent culture with bacteriuria. In 9 patients (13.5%), urine and stent cultures were identical (E. coli 4, Pseudomonas 4, Candida 1). The incidence of stent colonization did not correlate with stent dwelling time. The sensitivity of urine cultures for the detection of stent colonization was poor, being 31% only. In a specific patient with negative urine culture, the probability of stent colonization was 36%., Conclusion: A sterile urine culture does not rule out the stent itself being colonized. Therefore, patients with indwelling ureteral stents and a sterile urine culture may benefit from prophylactic antibiotic treatment prior to endourologic procedures. The prophylactic regimen must provide coverage for common gram-negative uropathogens as well as gram-positive bacteria, including enterococci.

In the last three decades, minimally invasive techniques have progressed significantly, replacing traditional open surgery as the mainstay of stone disease surgical treatment. The challenge for the next millennium remains medical prevention of calcium urolithiasis, a field where less dramatic progress has been achieved during the same period of time. The purpose of this article is to provide the practicing urologist with current practical guidelines for the assessment and management of calcium urolithiasis patients. The recommendations are based on the latest available information regarding the pathogenesis, medical treatment options, and decision-making rationale when managing these challenging patients. Every urolithiasis patient should undergo a basic evaluation, which is considered the minimal essential diagnostic work-up, in order to rule out obvious, treatable systemic causes of urinary stone disease. All patients should be advised about conservative nonspecific preventive measures. High-risk stone patients should have a more extensive metabolic evaluation based on two 24-hour urine samples. Treatment protocols for each patient are tailored individually according to the metabolic evaluation findings.

The long-term effects of extracorporeal shockwave lithotripsy (SWL) on the kidneys of children treated for renal calculi are unclear. In order to determine if SWL has any negative effects on renal growth rates, we reviewed long-term (mean 9-year) follow-up data on 29 pediatric patients treated between 1984 and 1988 with an unmodified Dornier HM3 lithotripter. Changes in renal length, serum creatinine, and blood pressure were analyzed. Predicted renal growth was calculated using a formula for age-adjusted renal length. Treated kidneys were stratified into normal and abnormal groups based on a history of renal surgery, evidence of recurrent infection, and obvious anatomic abnormalities. Fifty-six upper urinary tract calculi were treated in 34 renal units. Twenty-two renal units (68%) were rendered stone free, and 65% of the patients continue to be stone free. At follow-up, one patient was classified as having new-onset hypertension, and the mean serum creatinine was 0.93 +/- 0.08 mg/dL. Both at treatment and at follow-up, no significant differences were found in the sizes of the treated and untreated kidneys. However, at treatment, the abnormal group of kidneys seemed to be smaller than expected (mean Z -1.30 +/- 1.10), whereas the group of normal kidneys was very close (mean Z 0.18 +/- 0.54) to the predicted length. At follow-up, the deviations between actual and predicted renal length were significantly more negative. Treated kidneys were an additional 1.26 +/- 0.49 SD units below their expected length (p = 0.02). Untreated kidneys were further below normal as well but possibly to a lesser degree (-0.82 +/- 0.36; p <0.04). Although there was a trend for the abnormal group to have smaller kidneys than the normal group, both groups showed the same trend toward an age-adjusted reduction in renal growth at follow-up. The alterations in renal growth patterns observed in this population are unsettling and could be secondary to either treatment effect (SWL) or, more likely, to some underlying pathology intrinsic to pediatric kidneys with urolithiasis. Until further data are available, SWL in the pediatric population should be applied with caution and at the lowest dosage sufficient to achieve stone comminution.

Stone comminution and tissue damage in lithotripsy are sensitive to the acoustic field within the kidney, yet knowledge of shock waves in vivo is limited. We have made measurements of lithotripsy shock waves inside pigs with small hydrophones constructed of a 25-microm PVDF membrane stretched over a 21-mm diameter ring. A thin layer of silicone rubber was used to isolate the membrane electrically from pig fluid. A hydrophone was positioned around the pig kidney following a flank incision. Hydrophones were placed on either the anterior (shock wave entrance) or the posterior (shock wave exit) surface of the left kidney. Fluoroscopic imaging was used to orient the hydrophone perpendicular to the shock wave. For each pig, the voltage settings (12-24 kV) and the position of the shock wave focus within the kidney were varied. Waveforms measured within the pig had a shape very similar to those measured in water, but the peak pressure was about 70% of that in water. The focal region in vivo was 82 mm x 20 mm, larger than that measured in vitro (57 mm x 12 mm). It appeared that a combination of nonlinear effects and inhomogeneities in the tissue broadened the focus of the lithotripter. The shock rise time was on the order of 100 ns, substantially more than the rise time measured in water, and was attributed to higher absorption in tissue.

Acoustic cavitation damage was quantitated using aluminum foil targets placed within 2-mL polypropylene cryovials. The vials contained various media tested for their potential to support cavitation and were exposed to shock waves using an unmodified Dornier HM3 lithotripter. Foil damage, expressed in terms of a "damage index," was measured from digitized light microscopy images by quantitating the spread of gray-scale histograms. Target sensitivity was demonstrated by reproducible dose-response curves over the range (1-200 shock waves) commonly used for in vitro cell injury studies. Increased shock wave repetition rate reduced the damage index. Untreated foils showed a very low damage index (0.001% +/- 0.001%), while treated foils submerged in Ringer buffer yielded significant damage (2.2% +/- 0.3%, p < 0.001). Degassing the buffer reduced damage to 0.3% +/- 0.1% (p < 0.001). Foils submerged in castor oil showed virtually no damage. These results implicate acoustic cavitation in target damage. Targets immersed in biological fluids (blood and urine) had significantly less damage than in Ringer. The effect of degassing was also evaluated in a red blood cell lysis assay. Hemoglobin release in degassed preparations was significantly reduced compared to nondegassed controls (p < 0.001) and correlated with reduced foil damage index in cell-free vials. These findings characterize a sensitive method to quantitate acoustic cavitation and implicate a role for cavitation in shock wave lithotripsy-induced cell lysis.