The Fate of Residual Fragments After Percutaneous Nephrolithotomy: Results from the Endourologic Disease Group for Excellence Research Consortium.

Background: Residual fragments (RFs) after percutaneous nephrolithotomy (PCNL) have a significant impact on patients' quality of life and clinical course. There is a paucity of studies that evaluate the natural history of RFs after PCNL. The objective of this study is to compare rates of reintervention, complications, stone growth, and passage in patients with RFs >4, ≤4, and ≤2 mm after PCNL. Methods: Sites from the Endourologic Disease Group for Excellence (EDGE) research consortium examined data of PCNL patients from 2015 to 2019 with at least 1-year follow-up. RF passage, regrowth, reintervention, and complications were recorded and RFs were stratified into >4 and ≤4 mm groups, as well as >2 and ≤2 mm groups. Potential predictors for stone-related events after PCNL were determined using multivariable logistic regression analysis. It was hypothesized that larger RF thresholds would result in lower passage rates, faster regrowth, and greater clinically significant events (complications and reinterventions) than smaller RF thresholds. Results: A total of 439 patients with RFs >1 mm on CT postoperative day 1 were included in this study. For RFs >4 mm, rates of reintervention were found to be significantly higher and Kaplan-Meier curve analysis showed significantly higher rates of stone-related events. Passage and RF regrowth were not found to be significantly different compared with RFs ≤4 mm. However, RFs ≤2 mm had significantly higher rates of passage, and significantly lower rates of fragment regrowth (>1 mm), complications, and reintervention compared with RFs >2 mm. On multivariable analysis, older age, body mass index, and RF size were found to be predictive of stone-related events. Conclusions: With the largest cohort to date, this study by the EDGE research consortium further confirms that clinically insignificant residual fragment is problematic for patients after PCNL, particularly in older more obese patients with larger RFs. Our study underscores the importance of complete stone clearance post-PCNL and challenges the use of Clinically insignificant residual fragment (CIFR).

Prospective randomized trial of 2 versus 12-weeks of postoperative antibiotics after percutaneous nephrolithotomy in complex patients with infection-related kidney stones.

PURPOSE: Treatment of struvite kidney stones requires complete surgical stone removal combined with antibiotic therapy to eliminate urinary tract infections and preventive measures to reduce stone recurrence. The optimal duration of antibiotic therapy is unknown. We sought to determine if 2- or 12-weeks of antibiotics post percutaneous nephrolithotomy (PNL) for infection stones resulted in better outcomes for stone recurrence and positive urine cultures. MATERIAL AND METHODS: This multi-center, prospective randomized trial evaluated patients with the clinical diagnosis of infection stones. Patients were randomized to 2- or 12-weeks of postoperative oral antibiotics (nitrofurantoin or culture-specific antibiotic) and included if residual fragments were ≤4 mm on computed tomography imaging after PNL. Imaging and urine analyses were performed at 3-, 6-, and 12-months post-procedure. RESULTS: Thirty-eight patients were enrolled and randomized to either 2-weeks (n = 20) or 12-weeks (n = 18) of antibiotic therapy post-PNL. Eleven patients were excluded due to residual fragments >4 mm, and 3 patients were lost to follow-up. The primary outcome was the stone-free rate (SFR) at 6 months post-PNL. At 3-, 6-, and 12-months follow-up, SFRs were 72.7% versus 80.0%, 70.0% versus 57.1%, 80.0% versus 57.1% (p = ns), between 2- and 12-week-groups, respectively. At 3-, 6-, and 12-months follow-up, positive urine cultures were 50.0% versus 37.5%, 50.0% versus 83.3%, and 37.5% versus 100% between 2- and 12-week groups, respectively (p = ns). CONCLUSIONS: For patients with stone removal following PNL, neither 2-weeks nor 12-weeks of postoperative oral antibiotics is superior to prevent stones and recurrent positive urine cultures.

Predictors of urosepsis in struvite stone patients after percutaneous nephrolithotomy.

PURPOSE: This study aims to identify clinical factors that may predispose struvite stone patients to urosepsis following percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: A retrospective review was conducted on patients who received PCNL for struvite stones. The Systemic Inflammatory Response Syndrome (SIRS) criteria and quick-Sepsis Related Organ Failure Assessment (q-SOFA) criteria were used to identify patients who were at an increased risk for urosepsis. Statistical analysis was performed using Fisher's exactness test, Wilcoxon rank test, and logistic regression. RESULTS: Chart review identified 99 struvite stone patients treated with PCNL. Post-operatively, 40 patients were SIRS positive (≥2 criteria) and/or q-SOFA positive (score ≥2). Using SIRS as an approximation for urosepsis, longer operative times (p<0.001), higher pre-operative white blood cell counts (p=0.01), greater total stone surface area (p<0.0001), and pre-operative stenting (OR, 5.75; p=0.01) were identified as independent risk factors for urosepsis. Multivariate analysis demonstrated pre-operative stenting (OR, 1.46; p=0.01) to be a risk factor. With q-SOFA, univariable analysis found that antibiotic use within 3 months prior to a PCNL (OR, 4.44; p=0.04), medical comorbidities (OR, 4.80; p=0.02), longer operative times (p<0.001), lengthier post-operative hospitalization (p<0.01), and greater total stone surface area (p<0.0001) were risk factors for urosepsis. Multivariate analysis revealed that bladder outlet obstruction (OR, 2.74; p<0.003) and pre-operative stenting (OR, 1.27; p=0.01) significantly increased odds of being q-SOFA positive. CONCLUSIONS: Several risk factors for urosepsis following PCNL for struvite stones have been identified. These risk factors should be taken into consideration in peri-operative care to mitigate the risks of urosepsis.

Introduction of an ex-vivo pig model for teaching percutaneous nephrolithotomy access techniques.

INTRODUCTION: In North America, obtaining access for percutaneous nephrolithotomy (PCNL) is not often performed by urologists. Hands-on training sessions help to ensure this skill continues within the urological community. An ex-vivo pig kidney model was developed for simulation. This model uses porcine tissues with a fluoroscopic C-arm and standard PCNL equipment. The bullseye or triangulation techniques are both possible. We propose this as a high-fidelity tool for teaching PCNL access. METHODS: The pig kidney, fat, ribs, flank, and skin were arranged anatomically on a table with fluoroscopy. Hands-on training was provided to residents and urologists using the ex-vivo pig model and a silicone-based percutaneous access model. Questionnaires were given at the end of the session. RESULTS: There was a total 14 responders for each model, with incomplete responses on two surveys. A total of 15% of responders for the pig model and 7% of responders for the silicone model had previous percutaneous access experience. For the pig model, 93% of trainees agreed or strongly agreed that the model was easy to use, and 79% of the silicone model trainees felt the same. After the session, 50% of silicone model trainees and 86% of pig model trainees reported increased confidence in their ability to obtain PCNL access. All the pig model trainees and 71% of the silicone model trainees felt that the simulation activity was worthwhile. CONCLUSIONS: The inexpensive but anatomically realistic ex-vivo pig model using real-world equipment provides trainees with an excellent tool to learn PCNL access.

Total Surface Area Influences Stone Free Outcomes in Shock Wave Lithotripsy for Distal Ureteral Calculi.

Introduction: Current American Urological Association guidelines recommend ureteroscopy (URS) as primary management of distal ureteral stones and shock wave lithotripsy (SWL) as a secondary option. Utilization of SWL in the management of nephrolithiasis in North America has decreased. We hypothesized that SWL continues to be an effective option in the management of distal ureteral calculi and studied data from our center in patients who received SWL for distal ureteral stones. Methods: A retrospective review was performed of 104 patients treated initially with SWL for distal ureteral calculi between 2011 and 2018 at this institution. The success rate of SWL was assessed through radiologic imaging and if subsequent procedures were required to render patients stone free. Results: Operative note and chart review identified 104 patients who presented with distal ureteral stones and were treated with SWL as the initial form of management. Average patient age was 52.2 ± 15.3 years, average BMI was 27.4 ± 5.7, and average total axial stone surface area was 25.96 ± 14.32 mm2. Of these patients, 78.8% (n = 82) were stone free following one SWL and required no subsequent procedures. Of these patients, 87.5% (n = 91) were stone free following a second SWL, and 87.5% (n = 91) were stone free following a secondary URS. After the initial SWL, residual stones were identified in 21.2% of patients (n = 22). Four patients, 3.8%, required a salvage URS following a failed second SWL to achieve stone-free status. Conclusion: One SWL procedure offers a stone-free rate (SFR) of 78.8% and after two SWLs an 87.5% SFR. Only 12.5% of patients undergoing SWL at our center required URS to achieve a stone-free status. SWL is an effective modality in the treatment of distal ureteral stones.

Complications, Re-Intervention Rates, and Natural History of Residual Stone Fragments After Percutaneous Nephrolithotomy.

INTRODUCTION: The management of residual fragments (RFs) that persist after percutaneous nephrolithotomy (PCNL) has been poorly studied. Fragments have the potential to grow or cause symptoms. The aim of this study was to follow patients with fragments after PCNL to identify predictors of stone-related events (re-interventions and complications) after PCNL. PATIENTS AND METHODS: Data were retrospectively collected from patients who underwent surgery from 2008 to 2013 at our hospital. Patients with fragments of any size on postoperative day 1 computed tomography of the kidney, ureter, and bladder radiograph (CT-KUB) were included, and patients with planned secondary interventions were excluded. Subgroup analysis was performed on subjects with CT-plain X-ray to determine fragment growth or passage. RESULTS: Of the 658 patients who received a postoperative CT-KUB on day 1, 299 patients (45%) had fragments that were 1 mm or larger. From this, 263 patients met the study criteria and were included. The size of fragments, using a 4 mm cutoff, did not predict the passage of fragments (p = 0.173) or growth (p = 0.572). On multivariable logistic regression analysis, previous history of renal stones and size of fragment were found to be predictive for stone-related events (p = 0.002 and 0.027, respectively). Kaplan-Meier analysis identified patients with fragments >4 mm having a shorter survival time before the occurrence of stone-related events (p = 0.044). CONCLUSIONS: The true stone-free rate was 55% after PCNL. However, 82.5% were stone free or had RFs 4 mm or less, which correlates with previous studies. Larger RFs had higher rates of stone-related events and shorter time to occurrence of stone-related events. The growth and spontaneous passage of RFs was independent of RF size, emphasizing the importance of obtaining a stone-free status after PCNL.

Percuflex Helical Ureteral Stents Significantly Reduce Patient Analgesic Requirements Compared to Control Stents.

INTRODUCTION AND OBJECTIVES: Ureteral stent symptoms are experienced by the majority of patients with ureteral stents. No one stent or technology has shown a clear advantage. The Helical™ stent, a spirally cut stent made of proprietary Percuflex™ material, was designed to conform to the shape of the ureter and better accommodate patient movement. We prospectively sought to compare unscheduled visits, analgesic use, and pain scores in patients who received a Percuflex Helical ureteral stent following ureteroscopy compared to a historical control group. METHODS: Fifteen (n = 15) patients undergoing ureteroscopy for the treatment of kidney stones were consented for study. A Percuflex Helical ureteral stent was inserted after treating the urinary stone. The historical control group consisted of 30 patients, from a previous (ketorolac eluting) ureteral stent study utilizing the same protocol and clinical monitoring forms, who received a regular Percuflex ureteral stent. The control patients were matched by age and sex. The primary study outcome was to compare unscheduled visits. Secondary outcomes included comparison of Visual Pain Analog Scale (VPAS) scores and analgesic use between the two groups. RESULTS: There were no differences in the gender, age, BMI, or stone characteristics between groups. Both groups underwent retrograde ureteroscopy using holmium:YAG laser lithotripsy and stone fragmentation. There was a significant reduction in the amount of analgesics required in the Helical stent group (4.4 ± 7.99 mg morphine equivalents) compared to controls (16.75 ± 18.31 mg, p = 0.0035) to achieve similar VPAS scores. There was no difference in unscheduled visits (20%) or VPAS scores (13.84 ± 13.68 helical vs 14.29 ± 11.58 control, p = 0.7910) between groups. CONCLUSIONS: Patients who received a Percuflex Helical ureteral stent required significantly fewer analgesics than those who received a Percuflex stent and both had equivalent pain scores.

Randomized Controlled Trial Comparing Three Different Modalities of Lithotrites for Intracorporeal Lithotripsy in Percutaneous Nephrolithotomy.

PURPOSE: To compare the efficiency (stone fragmentation and removal time) and complications of three models of intracorporeal lithotripters in percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: Prospective, randomized controlled trial at nine centers in North America from 2009 to 2016. Patients were randomized to one of three lithotripter devices: the Cyberwand, a dual-probe ultrasonic device; the Swiss Lithoclast Select, a combination pneumatic and ultrasonic device; and the StoneBreaker, a portable pneumatic device powered by CO2 cartridges. Since the StoneBreaker lacks an ultrasonic component, it was used with the LUS-II ultrasonic lithotripter to allow fair comparison with combination devices. RESULTS: Two hundred seventy patients were enrolled, 69 were excluded after randomization. Two hundred one patients completed the study: 71 in the Cyberwand group, 66 in the Lithoclast Select group, and 64 in the StoneBreaker group. The baseline patient characteristics of the three groups were similar. Mean stone surface area was smaller in the StoneBreaker group at 407.8 mm2 vs 577.5 mm2 (Lithoclast Select) and 627.9 mm2 (Cyberwand). The stone clearance rate was slowest in the StoneBreaker group at 24.0 mm2/min vs 28.9 mm2/min and 32.3 mm2/min in the Lithoclast Select and Cyberwand groups, respectively. After statistically adjusting for the smaller mean stone in the StoneBreaker group, there was no difference in the stone clearance rate among the three groups (p = 0.249). Secondary outcomes, including complications and stone-free rates, were similar between the groups. CONCLUSIONS: The Cyberwand, Lithoclast Select, and the StoneBreaker lithotripters have similar adjusted stone clearance rates in PCNL for stones >2 cm. The safety and efficacy of these devices are comparable.

Benchtop and Initial Clinical Evaluation of the ShockPulse Stone Eliminator in Percutaneous Nephrolithotomy.

PURPOSE: Standardized bench testing of the new ShockPulse™ intracorporeal lithotripter was performed against three commercially available lithotripsy systems to determine differences and nuances in performance. MATERIALS AND METHODS: The ShockPulse intracorporeal lithotripter was tested against the LUS-2™, CyberWand,™ and EMS LithoClast™ in a standardized bench setting using hard (Ultracal-30) and soft (plaster of Paris) stone phantoms. An in vitro kidney model was used to record the time needed to fragment stone samples into retrievable-sized pieces. The time needed to fully comminute and evacuate stone samples was also recorded. The efficacy of each device at various applied pressures was determined using a hands-free apparatus, which was used to apply 1.0, 1.5, and 2.0 pounds of fixed force. RESULTS: For hard and soft stones, the time needed to create retrievable fragments was similar among all systems (p = 0.585). The ShockPulse was significantly faster than the LUS-2 and LithoClast at fully fragmenting and evacuating stone samples (p = 0.046), while the CyberWand was significantly slower than all three systems at this task (p = 0.001). When fixed forces were applied to a large stone phantom, the ShockPulse and CyberWand were significantly faster than the LUS-2 and LithoClast (p < 0.0001). When groups of smaller stones were tested, the ShockPulse was significantly faster at 1.0 pound (p < 0.001) and 1.5 pounds (p < 0.002) of force. At 2.0 pounds, no differences were observed (p = 0.09). CONCLUSIONS: The ShockPulse is equally as effective and, in some circumstances, more effective than the three commercially available devices against which it was tested in an in vitro setting.

A Single Dose of Intraoperative Antibiotics Is Sufficient to Prevent Urinary Tract Infection During Ureteroscopy.

BACKGROUND: American Urology Association (AUA) Best Practice Guidelines for ureteroscopic stone treatment recommend antibiotic coverage for <24 hours following the procedure. The purpose of this study was to evaluate if the addition of postoperative antibiotics reduces urinary tract infections (UTIs) following ureteroscopic stone treatment beyond the recommended preoperative dose. METHODS: A retrospective review was performed of consecutive patients at two institutions, University of British Columbia and Massachusetts General Hospital, Harvard. All patients received a single dose of antibiotics before ureteroscopic stone treatment. A subset of patients was also given postoperative antibiotics. The rate of UTI was compared in patients receiving only preoperative antibiotics (group 1) vs those who received pre- and postoperative antibiotics (group 2). RESULTS: Eighty-one patients underwent ureteroscopy for renal calculi. Mean time to follow up was 42 ± 88 days. Eight (9.9%) patients in total (two from group 1 and six from group 2, p = 0.1457) developed UTIs postoperatively. In group 1, both patients presented with pyelonephritis (n = 2); those patients with infections in group 2 presented with urosepsis (n = 2) and cystitis (n = 2) and two patients had asymptomatic bacteriuria. Risk factors such as preoperative stenting, nephrostomy tubes, and foley catheters neither differed between groups nor did they predispose patients to postoperative infections. CONCLUSIONS: The postoperative UTI rate in this study (9.9%) is consistent with previous reports. Our data suggest that a single preoperative dose of antibiotics is sufficient, and additional postoperative antibiotics do not decrease infection rates after ureteroscopic stone treatment. Risk for selection bias is a potential limitation.

Evaluation of risk factors and treatment options in patients with ureteral stricture disease at a single institution.

INTRODUCTION: Ureteral strictures are a significant cause of morbidity and mortality, resulting in potential kidney damage requiring several surgical procedures. Non-malignant causes include radiation, trauma from calculi impaction, pelvic surgery, or ureteroscopy (URS). We identified risk factors in our patients with ureteral strictures and the success of their treatment outcomes. METHODS: A retrospective chart review of 25 patients with 29 ureteral strictures was performed to determine the success of their treatment. RESULTS: Twenty-five (25) patients with 29 benign ureteral strictures were identified. Most cases (60%) were caused by impacted stones where the median stone size was 1.15 cm (0.37-1.8 cm). Intervention for stones prior to stricture development included shockwave lithotripsy, URS, and percutaneous nephrolithotomy. Five patients with strictures from impacted stones had ureteric complications during stone treatment including perforation +/- urinoma (n=3), fractured guidewire left in situ (n=1), and ureteric orifice resection (n=1). Other stricture etiologies included radiation (28%) and endometriosis (4%). Treatment modalities used included ureteroureterostomy (n=2), ureteral re-implant (n=3), urinary diversion (n=3), autotrasplant (n=1), laser endoureterotomy +/- balloon dilation (n=8), nephrectomy (n=2), balloon dilation +/- stent (n=3), ureterovesical junction (UVJ) resection + stent (n=1), chronic stent changes (n=4), or surveillance (n=3). CONCLUSIONS: Our evaluation highlights important principles. Patients with complicated ureteroscopies or severely impacted calculi warrant close followup with imaging after stone treatment due to possibility of rapid renal deterioration from stricture formation. Radiation-induced strictures are difficult to manage, possibly requiring subsequent urinary diversion. Finally, endoscopic management of benign ureteral strictures via balloon dilation and laser endoureterotomy is an excellent choice in properly selected patients, with opportunity for subsequent salvage treatments if needed.

Percutaneous nephrolithotomy for removal of encrusted ureteral stents: a multicenter study.

PURPOSE: Encrusted ureteral stents are a challenging endourologic problem. We performed a multi-institutional review of percutaneous nephrolithotomy (PCNL) as primary treatment for encrusted stents. MATERIALS AND METHODS: We identified 36 patients who underwent PCNL for treatment of an encrusted stent. A retrospective review was performed to compile details of procedures and outcomes for these patients. RESULTS: In 36 patients, 38 renal units underwent PCNL for encrusted ureteral stents. The mean patient age was 47.1 years (±16.7), and the female:male ratio was 15:21. Mean stent indwelling time before removal was 28.2 months (±27.8). The reason for long indwelling time was reported in 25 cases; these reasons included "patient unaware stent needed to be removed" (17 cases), pregnancy (2 cases), other comorbidities (3 cases), and patient incarceration (3 cases). In 3 cases, the stent had become encrusted within 3 months of placement. Mean operative time was 162 minutes (±71). There were no major intraoperative complications, and no patients required blood transfusion. Litholapaxy was required for bladder coil encrustations in 22 cases (58%), and ureteroscopy with lithotripsy was required for encrustation of the ureteral portion of the stent in 13 cases (34.2%). Second look percutaneous procedures were required in 13 cases (34.2%). The stent was removed at the time of PCNL without need for concomitant or delayed ureteroscopy and/or cystolitholapaxy in 8 cases (21%). Ultimately, all stents were removed successfully. Patients were rendered stone free according to radiographs in 24 cases (63%). CONCLUSIONS: In this multicenter review, PCNL is confirmed to be a safe and effective means of addressing the retained and encrusted ureteral stent. PCNL without ureteroscopy or litholapaxy was sufficient in a minority of cases (21%). Adjunctive endourologic modalities are often required, and the surgeon should anticipate the need for concomitant antegrade ureteroscopic laser lithotripsy and/or cystolitholapaxy. Although complete stent removal can be anticipated, residual fragments are not uncommon.

Genitourinary tuberculosis masquerading as a ureteral calculus.

The genitourinary tract is a common extrapulmonary site of tuberculosis infection, yet remains a rare clinical entity in North America. We report the case of a 37-year-old man who presented for extracorporeal shock wave lithotripsy for a suspected ureteral stone on imaging. Further workup confirmed a diagnosis of genitourinary tuberculosis. Medical management was undertaken and, ultimately, nephrectomy performed. This case highlights the importance of maintaining a high index of clinical suspicion for genitourinary tuberculosis.

A multicenter comparison of the safety and effectiveness of ureteroscopic laser lithotripsy in obese and normal weight patients.

OBJECTIVE: Surgical treatment of kidney stones in an obese patient (body mass index [BMI] >30 kg/m(2)) remains challenging as shockwave lithotripsy may not be an option due to weight limitations. We sought to determine the effectiveness of ureteroscopic laser lithotripsy in obese patients compared to nonobese controls. MATERIALS AND METHODS: Patients from 2004 to 2007 were retrospectively analyzed providing a group of 292 patients (163 obese, 76 overweight, 53 normal) who underwent ureteroscopic procedures for urolithiasis at four centers in the United States and Canada. RESULTS: The percentage of obese patients requiring flexible ureteroscopy (URS) (79%) was higher than in the other groups (P<0.0001). Flexible URS was associated with a lower stone-free rate (SFR) on multivariate analysis (P=0.034). There was no difference in SFRs of patients who required a ureteral access sheath, basket extraction, or received a postoperative stent. Complication rates did not differ between groups. CONCLUSION: SFRs using ureteroscopic lithotripsy in obese and overweight populations are the same as in the normal weight patients. A flexible ureteroscope was associated with a decreased SFR, but this likely due to a more proximal stone location in these patients. Ureteroscopic laser lithotripsy is an effective and safe technique to treat urolithiasis in the overweight/obese patient.

In vivo evaluation of the third generation biodegradable stent: a novel approach to avoiding the forgotten stent syndrome.

PURPOSE: Ureteral stents are prone to irritation, encrustation and infection, and they require additional procedures for removal. Furthermore, indwelling polymer stents are often forgotten with devastating consequences to the patient. We describe the degradation time, and physiological and histological responses elicited by a novel biodegradable ureteral stent in a porcine model. MATERIALS AND METHODS: A total of 16 female Yorkshire pigs were used in the study. Ten biodegradable Uriprene™ stents and 6 biostable Polaris™ stents were cystoscopically inserted unilaterally in 2 groups of animals. Excretory urogram, and blood and urine tests were performed on different days until day 28. Biostable stents were removed on day 21. On day 28 all pigs underwent necropsy for microscopic and histological evaluation. RESULTS: Nine of the 10 biodegradable stents (90%) degraded completely by 4 weeks, while 1 pig had 3 fragments smaller than 1.5 cm in the bladder. Excretory urogram showed equivalent drainage and significantly less hydronephrosis in biodegradable stented kidneys. Blood and urine parameters were similar in the 2 groups. A transient increase in serum creatinine on day 7 in 40% of the pigs with a degradable stent resolved by day 10. There were significantly fewer abnormal histological findings in the degradable stent group. We evaluated drainage characteristics in an unobstructed ureter and results may not be representative of what develops in obstructed ureters. CONCLUSIONS: The third generation biodegradable stent is a safe, effective alternative to conventional polymer stents, resulting in equivalent drainage and less hydronephrosis.

Twenty-year prevalence of diabetes mellitus and hypertension in patients receiving shock-wave lithotripsy for urolithiasis.

OBJECTIVES: To compare the prevalence of hypertension and diabetes mellitus (DM) in patients treated with an unmodified HM-3 lithotripter (USWL) and a second-generation modified HM-3 lithotripter (MSWL) 20 years ago at our Centre with that in the provincial population. To determine whether the type of lithotripter was differentially associated with the development of these sequelae. PATIENTS AND METHODS: Retrospective review of 727 patients at Vancouver General Hospital who underwent shock-wave lithotripsy (SWL) between 1985 and 1989. Our study group was compared with Statistics Canada data describing the provincial prevalence of these diseases. Multivariate analysis was performed. RESULTS: The response rate was 37.3%. There was a greater proportion of overweight and obese individuals in the study group compared with the provincial average. In univariate analysis, lithotripsy with an unmodified HM-3 (USWL) was associated with a higher rate of DM than the provincial rate, whereas lithotripsy with the modified HM-3 (MSWL) was not. Hypertension was more prevalent in all lithotripsy subjects. On multivariate analysis the type of lithotripter was not associated with the development of either sequela. CONCLUSIONS: No association between lithotripsy and the development of either DM or hypertension in a multivariate analysis Metabolic syndrome may have elevated the prevalence of DM and hypertension observed in our subjects on univariate analysis, which is in keeping with the fact that our study population had statistically higher body mass indices than the provincial rate. Lithotripsy using the HM-3 was not associated with increased DM or hypertension.

The Canadian StoneBreaker trial: a randomized, multicenter trial comparing the LMA StoneBreaker™ and the Swiss LithoClast® during percutaneous nephrolithotripsy.

BACKGROUND AND PURPOSE: Percutaneous nephrolithotripsy (PCNL) is the treatment of choice for patients with large renal stones. The StoneBreaker™ (SB) is a novel handheld pneumatic lithotriptor, powered by a compressed carbon dioxide cartridge. The purpose of this study was to compare the efficiency of the SB to a standard pneumatic lithotriptor, the Swiss LithoClast(®) (LC). PATIENTS AND METHODS: From January 2008 to December 2009, patients undergoing PCNL were randomized to either the SB or the Swiss LC. Primary outcomes included time to fragment the stone, retrieve the fragments, and remove debris using ultrasonic lithotripsy. Secondary end points were stone-free rate, lithotriptor setup time, ease of use, operator fatigue, endoscopic visualization, damage to mucosa, and device-related complications. RESULTS: Of the initial 115 patients recruited, 77 were enrolled and 38 were excluded. The SB had significantly faster stone fragmentation time, total lithotripsy time, and setup time than the Swiss LC (P ≤ 0.05). A significant difference was also noted in the ease of use and operator fatigue in favor of the SB. There were no device-related complications. CONCLUSION: The SB pneumatic lithotriptor is easier to set up and use, and it provides faster stone fragmentation than the Swiss LC.

Randomized controlled, multicentre clinical trial comparing a dual-probe ultrasonic lithotrite with a single-probe lithotrite for percutaneous nephrolithotomy.

OBJECTIVES: • To compare the Cyberwand (Gyrus/ACMI, Southborough, MA, USA), a dual-probe ultrasonic lithotrite, with a single-probe ultrasonic lithotrite. • The Cyberwand incorporates coaxial high- and low-frequency ultrasonic probes that work synergistically. PATIENTS AND METHODS: • An institutional review board-approved, multicentre, randomized controlled trial to compare the Cyberwand to the Olympus LUS-II (Olympus America, Inc., Melville, NY, USA) single-probe lithotrite was performed. • Patients undergoing a percutaneous nephrolithotomy (PCNL) with a target stone > 2 cm in diameter were eligible for the study. • The primary outcome was the time to removal of the targeted stone. RESULTS: • A total of 57 PCNLs were performed after randomization: 25 Cyberwand and 32 LUS-II. • There was no difference (P > 0.05) observed between the two devices for target stone surface area (Cyberwand 526.6 cm³ vs LUS-II 540.1 cm³), time to clearance of target stone (Cyberwand 15.8 min vs LUS-II 14.2 min) and target stone clearance rate (Cyberwand 61.9 mm²/min vs LUS-II 75.8 mm²/min). • Of the patients with stone analysis, hard stones (calcium oxalate monohydrate, brushite and cystine) were noted in 14 (56.0%) of the 25 Cyberwand and 18 (62.1%) of the 29 LUS-II patients. • Fifteen of the 25 (60.0%) Cyberwand and 20 of the 32 (62.5%) LUS-II patients were stone-free after the initial PCNL. • Those patients not rendered stone-free went on to receive a secondary PCNL. • Device malfunction occurred in eight of 25(32.0%) Cyberwand and five of 32 (15.6%) LUS II patients. • Complications were similar in both treatment groups. CONCLUSION: • No appreciable difference between the dual-probe Cyberwand and the standard ultrasonic Olympus LUS-II lithotrites can be identified.