Is extracorporeal shockwave lithotripsy a risk factor for the development of diabetes mellitus? A population-based study.

OBJECTIVE: To determine if patients treated with extracorporeal shockwave lithotripsy (ESWL) are at a greater risk of developing diabetes mellitus (DM) than those treated with ureteroscopy (URS). PATIENTS AND METHODS: A retrospective population-based cohort study was performed of all ESWL and URS stone treatments done in Ontario between January 1994 and March 2014, utilising linked encoded healthcare databases. The primary outcome was the development of DM >90 days after treatment. The Kaplan-Meier method was used for unadjusted survival analysis and multivariable analysis with Cox proportional hazards regression was used to assess the risk of DM between the ESWL and URS groups whilst controlling for age, gender, region of residence, income quintile, year of treatment, and comorbidity index. A sensitivity analysis with a subset of ESWL patients treated for left renal or proximal ureteric stones was completed. RESULTS: We identified 106 963 patients who underwent ESWL or URS over the study period with a median follow-up of 6.6 years (ESWL 8.5 years, URS 5.6 years). Unadjusted survival analysis showed an increased risk of developing DM in the ESWL group compared to the URS group (P < 0.001); however, multivariable analysis showed no increased risk of DM in the ESWL cohort (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.91-1.02; P = 0.25). Similarly, sensitivity analysis showed no increased risk of DM in the left renal/proximal ureteric stone ESWL cohort compared to the URS cohort (HR 1.04, 95% CI 0.96-1.13; P = 0.35). CONCLUSIONS: Our population-based cohort study demonstrated no increased risk of DM in patients undergoing ESWL compared to URS.

The role of prophylactic versus selective ureteric stenting in kidney transplant patients: a retrospective review.

OBJECTIVE: To evaluate the role of prophylactic versus selective ureteric stenting in the development of postoperative ureterovesical complications in kidney transplant recipients. METHODS: Records of 614 transplant patients seen from January 2006 to May 2011 were retrospectively reviewed. The primary outcome was the rate of ureterovesical complications, defined as the development of ureteric obstruction or a ureterovesical anastomotic leak. The secondary outcomes were the rate of urinary tract infections and forgotten stents. Using a χ2 test, we compared the primary and secondary outcomes across the selective and prophylactic cohorts. Logistic regression was used to compare the 2 cohorts while adjusting for potential confounders. RESULTS: The selective and prophylactic cohorts consisted of 258 and 330 patients, respectively. Unadjusted analysis showed that the prophylactic group had a significantly lower rate of ureterovesical complications than did the selective group (2.12% vs 6.20%; odds ratio, 0.33; P= .01). After adjustment for differences in sex and donor type, the prophylactic group still had a lower risk for ureterovesical complications (odds ratio, 0.30; P= .009). Rates of urinary tract infections and forgotten stents did not differ significantly between the 2 groups. CONCLUSIONS: Prophylactic stenting is associated with a significantly lower rate of ureterovesical complications than is selective stenting.

A prospective study examining the incidence of bacteriuria and urinary tract infection after shock wave lithotripsy with targeted antibiotic prophylaxis.

PURPOSE: Controversy exists regarding antibiotic prophylaxis before shock wave lithotripsy. The AUA (American Urological Association) guideline recommends universal antibiotic prophylaxis, whereas the EAU (European Association of Urology) guideline recommends prophylaxis only for select patients. We evaluated the use of targeted antibiotic prophylaxis in preventing urinary tract infections in patients undergoing shock wave lithotripsy. MATERIALS AND METHODS: A prospective single cohort study was performed during 6 months with patients undergoing shock wave lithotripsy. All patients underwent urine dipstick and culture before shock wave lithotripsy. Targeted antibiotic prophylaxis was provided at the discretion of the treating urologist. All patients had a urine culture performed after shock wave lithotripsy and completed a survey documenting fevers or urinary symptoms. The primary outcome was the incidence of urinary tract infections, urosepsis and asymptomatic bacteriuria after shock wave lithotripsy. The secondary outcome was the sensitivity and specificity of urinary dipstick leukocytes and nitrites. RESULTS: A total of 526 patients were enrolled in the study. Of the 389 patients included in the determination of the primary outcome, urinary tract infection developed in only 1 (0.3%), urosepsis did not develop in any patients and asymptomatic bacteriuria developed in 11 (2.8%). Eight (2.1%) patients were administered antibiotic prophylaxis. The specificity of urine dipstick nitrites was high (95%) while the sensitivity was poor (9.7%). CONCLUSIONS: In our cohort study using targeted antibiotic prophylaxis the rates of urinary tract infection after shock wave lithotripsy and rates of asymptomatic bacteriuria were extremely low, with no development of urosepsis. This finding questions the need for universal antibiotic prophylaxis before shock wave lithotripsy.

A clinical nomogram to predict the successful shock wave lithotripsy of renal and ureteral calculi.

PURPOSE: Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes. MATERIALS AND METHODS: During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter. RESULTS: A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (p<0.01), mean stone density (p<0.01) and skin to stone distance (p<0.01). By multivariate logistic regression for renal calculi, age, stone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70). CONCLUSIONS: Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations.

Clips Can be Safely Used for Vascular Control of the Renal Vessels During Laparoscopic Donor Nephrectomy.

OBJECTIVE: To review our experience using clips to control the renal vessels during laparoscopic donor nephrectomy (LDN) and determine the safety of this practice. METHODS: We performed a retrospective review of patients who underwent LDN at our centre January 1, 2007-September 17, 2019. The primary outcome was the rate of complication associated with vascular control of the renal vessels, which included (1) conversion to open to manage bleeding, (2) additional procedures for bleeding, and (3) major bleeding requiring blood transfusion. Secondary outcomes included the rate of renal artery/vein clip dislodgement or crossing, change in hemoglobin, warm ischemia time and the incidence of intra-operative complications and postoperative in-hospital complications. RESULTS: We included 503 patients who underwent LDN, of which 497 were left sided. The main renal artery was controlled with 3 titanium clips in 489 (97%) cases. The main renal vein was controlled with 2 polymer-locking clips in 478 (95%) cases. For our primary outcome, there were no conversions to open to manage bleeding, no secondary procedures due to bleeding and no major bleeding requiring blood transfusion. Additionally, there were no donor deaths. Regarding our secondary outcomes, there were 5 intraoperative events related to the titanium clips being placed on the renal artery and 1 intraoperative event related to the polymer-locking clips on the renal vein, none of which resulted in any morbidity. CONCLUSION: Using 3 titanium clips on the renal artery and 2 polymer-locking clips on the renal vein during left LDN is safe and provides excellent vascular control.

Evaluating the importance of mean stone density and skin-to-stone distance in predicting successful shock wave lithotripsy of renal and ureteric calculi.

Shock wave lithotripsy (SWL) is considered the first line treatment for the majority of patients with renal and ureteric calculi, with success rates from contemporary series varying from 60 to 90%. Success is dependent on many patient and stone-related factors. We conducted a retrospective analysis of mean stone CT density (MSD) and skin-to-stone distance (SSD) to determine their influence on the success of SWL of renal and ureteric calculi. Data from all patients treated at the St. Michael's Hospital Lithotripsy Unit from May 2004 to June 2009 were reviewed. Analysis was restricted to those patients with a pre-treatment non-contrast CT scan conducted at our center demonstrating a solitary renal or ureteric calculus < or =20 mm in maximal diameter. Successful treatment of renal stones was defined as those patients who were stone free or had asymptomatic, clinically insignificant residual fragments < or =4 mm in diameter, as measured by KUB X-ray, 3 months after a single SWL treatment. Successful treatment of ureteric stones was defined as being stone free on KUB X-ray, 2-weeks post-SWL. Demographic, stone, patient, treatment and follow-up data were collected from a prospective database and review of CT and KUB imaging by two independent urologists and one radiologist. Data were analyzed with logistic regression, Chi square analysis and ANOVA where appropriate. 422 patients (69.7% male) with a mean age of 51.4 years (SD 12.9) and mean BMI 27.0 kg/m(2) (SD 4.9) were analyzed. Mean stone size was 78.9 mm(2) (SD 77.3) for ureteral stones and 66.1 mm(2) (SD 63.2) for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single-treatment success rates for ureteral and renal stones were 62.3% and 68.8%, respectively. On univariate analysis, predictors of SWL success, regardless of stone location, were age (p = 0.01), BMI (p = 0.01), stone size (p < 0.01), MSD (p < 0.01) and SSD (p < 0.01). On multivariate analysis, MSD >900 HU (OR = 0.49, CI: 0.32-0.75) and SSD >110 mm (OR = 0.49, CI: 0.31-0.78) were both significant predictors of outcome. We have identified in a large series of renal and ureteric calculi that both MSD and SSD can reliably predict SWL outcomes. This data can be used in combination with other patient and stone-related factors to facilitate optimal treatment-based decisions and provide patients with more accurate single-treatment success rates for SWL.

Routine Preoperative Electrocardiograms in Patients at Low Risk for Cardiac Complications During Shockwave Lithotripsy: Are They Useful?

INTRODUCTION: Routine preoperative electrocardiogram (ECG) before shockwave lithotripsy (SWL) is frequently performed despite recommendations against its use in asymptomatic patients undergoing low-risk surgical procedures. This study assesses whether routine preoperative ECG before SWL is useful in patients at low risk for cardiac complications. MATERIALS AND METHODS: A retrospective study of SWL at our center (2003-2013) reviewed all cardiac-related preoperative cancellations, intraoperative complications, postoperative admissions, and emergency department presentations in patients at low risk for cardiac complications. Patients received SWL with sedation and continuous five-lead ECG monitoring. RESULTS: Of 30,892 referrals, preoperative ECG triggered 13 (0.04%) cancelations in low-risk patients (1 with new atrial fibrillation and 12 with ischemia/previous infarction). Of these patients, 1 had a subsequent abnormal cardiac work-up and 11 underwent uncomplicated SWL without cardiac intervention (2 had unknown history). Of 27,722 treatments, 5 (0.02%) were stopped prematurely in low-risk patients because of arrhythmia (3 had normal preoperative ECG, 1 had abnormal ECG, and 1 did not complete ECG). Three patients developed an arrhythmia with sedation and 2 patients were admitted postoperatively because of cardiac complications (1 for atrial fibrillation and 1 for hypertension), of whom all had normal preoperative ECG. No patients presented to our emergency department with cardiac complications after SWL. CONCLUSIONS: In patients at low risk for cardiac complications, preoperative ECG triggered very few cancellations and did not predict early termination of treatment or cardiac complications after SWL. These findings suggest that in low-risk patients, routine preoperative ECG has little effect on treatment or complication rate and should be omitted.

Dual usage of a stone basket: Stone capture and retropulsion prevention.

INTRODUCTION: Stone migration during ureteroscopy (URS) for proximal ureteric calculi is a constant challenge. Several retropulsion prevention devices have been developed to optimize URS outcomes. Our technique involves capturing the stone within a four-wire Nitinol stone basket and then performing laser lithotripsy to dust the stone while it is engaged in the basket. The dusted fragments wash out with the irrigation fluid and once small enough, the remaining stone is removed intact. METHODS: A retrospective chart review was performed of all proximal semi-rigid URS procedures for a solitary calculus (2000-2016). We compared our new technique introduced in 2010 to URS control procedures that did not use retropulsion prevention techniques or devices. RESULTS: One hundred and forty patients underwent URS for proximal ureteric calculi. Mean stone diameter was 9.3±3.4 mm, with similar impaction rate between both groups (44.1% vs. 43.1% control; p=n/s). The mean surgical procedure time was 53.3±17.9 minutes for the new technique and 65.2±29.2 minutes for the control group (p=0.005). Compared to the new technique, the control group had a higher rate of retropulsion (33.3% vs. 14.7%; p=0.01) and required flexible URS more often to exclude or remove residual fragments (24.1% vs. 59.1%; p=0.001). Using the new technique, stone-free rates were higher (79.1% vs. 69.4%; p=n/s) and there was a lower likelihood of leaving residual fragments both <3 mm and ≥3 mm (p=0.001). CONCLUSIONS: Our novel technique results in shorter operative times, lower retropulsion rates, and decreases postoperative residual stone fragments.

Intraoperative Radiographic Determination of Ureteral Length as a Method of Determining Ideal Stent Length.

INTRODUCTION: Accurate determination of ureteral length (UL) and appropriate stent length remains a challenge. The objective of this study was to describe an intraoperative technique to measure UL and determine appropriate stent length, and to compare this technique with other methods of determining appropriate stent length. METHODS: Patients undergoing ureteroscopy requiring postoperative stenting and who had a preoperative CT were prospectively identified. Gender, age, height, body mass index, L1 to L5 lumbar height on CT, and surgeon's estimate of UL were recorded. UL was measured using four methods: direct measurement with a ureteral catheter, ureteropelvic junction (UPJ) to ureterovesical junction distance on axial and coronal CT, and using a novel intraoperative radiographic technique. Radiographic measurement was performed using a radiographic nipple marker affixed to the skin over the ureteral orifice (UO) and an angiographic catheter with radiopaque markings at 1 cm intervals. UL was the distance from the UPJ to the marker at the UO measured using the catheter markers. Correlation between direct measurement and the recorded variables and methods of ureteral measurement were calculated. Stent length was chosen based on radiographic measurement. Stents were deemed of appropriate length if they showed a proximal coil in the renal pelvis and a distal coil in the bladder without crossing midline. RESULTS: Twenty-five ureters from 23 patients were included. Radiographically measured UL was strongly correlated with direct measurement. (r = 0.873, p < 0.01). Coronal and axial CT ULs were significantly associated with direct measurement (p < 0.05). Height, lumbar height, and surgeon's estimate of UL were not. Stents were deemed of appropriate length in 23/25 cases (92%). CONCLUSIONS: This new method for radiographic UL measurement is strongly correlated with directly measured UL. A length of stent chosen based on radiographic UL resulted in an appropriate stent length.

Status of urologic laparoscopy in 2004: a survey of CUA members.

INTRODUCTION: The optimal method of acquiring laparoscopic skills has not been determined. We sought to examine the current status of urologic laparoscopy and how practicing urologists acquired the skills needed to perform laparoscopic procedures. METHODS: A mail questionnaire regarding laparoscopic practices and training was sent to 480 members of the Canadian Urological Association (CUA) using standard Dillman survey methodology. RESULTS: Three hundred (62.5%) urologists responded to the questionnaire; 56.5% practiced in the community and 41.1% in an academic setting. There were 59.9% who had completed some form of fellowship training. Recent graduates (who finished residency after 1995) were more likely to perform all types of laparoscopic procedures compared to older graduates (65% versus 29.7%, p < 0.001). Advanced procedures were also performed more frequently by recent graduates (52.5% versus 23.4%, p < 0.001). Of those who do not currently perform laparoscopy, 38.2% plan to learn in the future. The most common method of acquiring laparoscopic skills was with animal laboratory experience (39.4%), but only 20.9% relied solely on this method. A trip to a centre of excellence (28.5%) and training from an urologist at the same institution (25.7 %) was also commonly reported as methods of acquiring skills. There were 48.8% who reported beginning laparoscopic procedures without a mentor. CONCLUSIONS: A substantial portion of the Canadian urological community employs laparoscopy, although recent graduates are more likely to do so. Training methods in laparoscopy are variable, but a substantial portion of urologists begin practicing laparoscopic procedures without formal mentoring.

Changing Patient Position Can Eliminate Arrhythmias Developing During Extracorporeal Shockwave Lithotripsy.

INTRODUCTION: Extracorporeal shockwave lithotripsy (SWL) has a low complication rate. While serious complications are rare, cardiac arrhythmias, such as ventricular tachycardia, may occur. The etiology of these arrhythmias is poorly understood, but it appears to be due to stimulation of the heart by the shock waves. OBJECTIVE: This study examines the effect of rotating the patient 15° to 20° when an arrhythmia occurs. METHODS: Eight hundred nineteen patients were prospectively evaluated for arrhythmias during SWL. The initial patient position was dependent on the location of the stone and the body mass index (BMI) of the patient. If a sustained arrhythmia developed, treatment was withheld for 2 minutes and then recommenced. If the patient developed an arrhythmia again, the patient was rotated 15°-20° away from the original position and treatment recommenced. RESULTS: Twenty patients developed significant arrhythmias during SWL. Arrhythmias occurred more frequently in patients with a lower BMI (p < 0.01), of younger age (p = 0.01), and with right-sided stones (p = 0.035). After the first rotation, 11 patients had no further arrhythmias, and 4 patients had a reduction of their arrhythmia to unsustained minor arrhythmias that did not require cessation of the treatment. The remaining five patients required a second repositioning. Three of these patients required gated SWL to abolish the arrhythmia. CONCLUSION: Changing the position of the patient by rotating the patient by 15 to 20° can eliminate arrhythmias that develop during SWL.

A randomized, double-blinded, placebo-controlled trial of intercostal nerve block after percutaneous nephrolithotomy.

BACKGROUND AND PURPOSE: The optimal method of pain control after percutaneous nephrolithotomy (PCNL) remains controversial. We sought to determine whether intercostal nerve block with bupivicaine provided superior pain control, when compared with placebo, with a lower need for narcotics and improved health-related quality of life (HRQL) in the immediate postoperative period. PATIENTS AND METHODS: Sixty-three patients were randomized to receive intercostal blockade with either 20 mL of 0.5% bupivacaine with epinephrine or 20 mL physiologic saline. All patients received intravenous narcotic patient-controlled analgesia (PCA) postoperatively. Data were collected on stone parameters, demographics, analgesic usage, length of stay, and HRQL as assessed by the Postoperative Recovery Scale. RESULTS: The mean age was 47.7±1.2 years; mean body mass index was 28.0±5.0 kg/m(2); mean stone diameter was 29.2±15.8 mm. Within the first 3 to 6 hours after surgery, there was a significant reduction in narcotic use for the group receiving intercostal nerve blockade with bupivacaine compared with placebo. At 3 hours, narcotic use was 2.4±3.1 mg vs 4.3±3.8 mg morphine equivalents (P=0.034), and within 6 hours of surgery, narcotic use was 5.9±6.1 mg vs 8.8±7.4 mg (P=0.096). Durable improvement in HRQL was also observed in patients receiving intercostal nerve blockade with bupivacaine compared with placebo (P=0.034). No complications were attributable to the intercostal nerve blocks in either group. CONCLUSIONS: Intercostal blockade with bupivacaine significantly improves both pain control and HRQL in the early postoperative period. The effectiveness of bupivacaine disappears within 6 hours of surgery, after which narcotic use becomes indistinguishable. Intercostal nerve blockade is an easy, safe, and inexpensive method that can be used to optimize pain control after PCNL.

Stones lodge at three sites of anatomic narrowing in the ureter: clinical fact or fiction?

UNLABELLED: Abstract Background and Purpose: Throughout the literature, the ureter is described as having three anatomic sites of narrowing at which kidney stones typically become lodged: The ureteropelvic junction (UPJ), the ureteral crossing of the iliac vessels, and the ureterovesical junction (UVJ). There is little evidence to support this notion, however. The purpose of our study is to evaluate whether three peaks in stone distribution corresponding to these anatomic landmarks exist. METHODS: We retrospectively reviewed the kidneys-ureters-bladder (KUB) films of 622 patients with solitary ureteral calculi referred for shockwave lithotripsy (SWL). Pretreatment KUB films were used to categorize the location of their ureteral stone relative to 1 of 19 levels referenced to the axial skeleton. CT scans of 74 patients were used to determine the location of the UPJ, ureteral crossing of the iliac vessels, and UVJ relative to the 19 levels on KUB radiography. Histograms were then constructed to plot the distribution of stones within the ureter relative to these 19 levels. The effect of sex, stone size and side, and presence of a stent on stone distribution were analyzed. RESULTS: There are two peaks in the distribution of stones within the ureter in patients referred for SWL that correspond to the UPJ/proximal ureter and intramural ureter/UVJ. In patients with larger stones (≥100 mm(2)) or a ureteral stent in place, stones were distributed more proximally (P<0.0001). When comparing sexes, there was a difference in stone distribution that approached significance (P=0.0523), with a greater peak more distally in males compared with females. CONCLUSIONS: Our review demonstrates a peak in the distribution of stones corresponding to the UPJ/proximal ureter and the intramural ureter/UVJ. We failed to demonstrate a peak in stone distribution corresponding with the ureteral crossing of the iliac vessels.

Does baseline radiography of the kidneys, ureters, and bladder help facilitate stone management in patients presenting to the emergency department with renal colic?

BACKGROUND AND PURPOSE: A baseline kidneys, ureters, and bladder (KUB) radiograph, at the time of computed tomography (CT) for ureteral stones, might aid interpretation of future KUBs. The CT scout radiograph might render the baseline KUB redundant, however. We sought to assess the diagnostic utility of baseline KUB for patients with ureteral stones. PATIENTS AND METHODS: Patients with ureteral stones were retrospectively identified. All had a baseline KUB in addition to CT and were reassessed after 4 to 60 days with KUB. Each patient's imaging was randomized 1:1 into either "KUB&CT" or "CT" groups. Three urologists independently assessed the imaging: CT (with scout film) and baseline KUB in the KUB&CT group, but only the CT (not KUB) in the CT group. Definitive stone assessment on follow-up KUB was defined as all three reviewers answering either Yes or No (not Indeterminate) to the question of stone passage or migration. RESULTS: Of 154 stones, the mean diameter was 4.8 ± 2.1 mm, density was 914 ± 300 Hounsfield units (HU), with 54.4% in the distal ureter. Stone visibility was 60.4% on KUB vs 43.5% on scout film (P<0.001). Scout film visibility favored the CT group (52.7 vs 35.0%, P = 0.027). After adjusting for body mass index, skin-to-stone distance, size, density, and location, definitive assessment rates were higher in the KUB&CT group (P = 0.047). When reviewers reassessed the CT group using the baseline KUB, they were able to do so definitively in an additional 16 (21.6%, P<0.001). Definitive assessments were associated with higher rates of stone visibility on scout film (86.1 vs 21.1%, P<0.001), KUB (86.1 vs 50.0%, P<0.001), and larger (6.0 vs 3.7 mm, P<0.001), denser stones (1046 vs 802 HU, P<0.001). CONCLUSIONS: The addition of a baseline KUB to the CT scout film improves the ability of urologists to determine stone outcome when following patients with KUB imaging and might reduce the subsequent need for additional imaging.

Does the radiologic technologist or the fluoroscopy time affect treatment success with shockwave lithotripsy?

BACKGROUND AND PURPOSE: The minimally invasive nature and effectiveness of shockwave lithotripsy (SWL) has made it one of the primary treatment modalities for urinary tract calculi. Several factors determining the success of SWL treatment have been studied, including stone factors (ie, location, size, and composition) and patient factors (ie, patient habitus and skin-to-stone distance). Our objective was to determine if either the assisting radiologic technologist or the amount of fluoroscopy time used has an impact on SWL success. PATIENTS AND METHODS: We compared the outcome of 536 SWL treatments across three radiologic technologists. We also evaluated the average amount of fluoroscopy time used in treatment success vs failures in this same cohort. The outcomes measured were stone-free and successful fragmentation rate at 2 weeks and 3 months. Successful fragmentation was defined as being either stone free, having residual sand, or with an asymptomatic fragment ≤ 4 mm on radiography of the kidneys, ureters, and bladder. RESULTS: The patients treated by the three different radiologic technologists were comparable with respect to body mass index, stone side and location, presence of ureteral stent, and mean stone area (mm(2)). The stone-free and successful fragmentation rates at 2 weeks and 3 months between the three radiologic technologists were not significantly different. When examining fluoroscopy time, we found a significantly greater mean fluoroscopy time was used in treatments with successful fragmentation at 2 weeks (3.16 min vs 2.72 min, P=0.0001) and 3 months (3.12 min vs 2.75 min, P=0.0015) compared with treatment failures. CONCLUSION: The radiologic technologist did not have a significant impact on SWL treatment outcome at 2 weeks and 3 months. Successful SWL fragmentation at 2 weeks and 3 months, however, was associated with a greater amount of fluoroscopy time, suggesting that using fluoroscopy to ensure accurate targeting during SWL is important for successful fragmentation.

Shockwave lithotripsy in patients with horseshoe kidney: determinants of success.

BACKGROUND AND PURPOSE: Horseshoe kidney (HSK) is the most common renal fusion anomaly, with a prevalence of ∼1 in 400 and an incidence of urolithiasis between 20% and 60%. The role of shock wave lithotripsy (SWL) in patients with HSK remains poorly studied. METHODS: Data from all patients treated since January 1994 with a known HSK was reviewed. Analysis was restricted to all patients with a minimum follow-up of 2 weeks after SWL. Success was defined as patients who were stone-free or had asymptomatic, clinically insignificant residual fragments ≤ 4 mm. RESULTS: Data from 41 patients with HSK were analyzed (61 calculi). Mean stone size was 91.3 ± 71.6 mm(2); mean body mass index was 27.1 ± 5.3 kg/m(2). At 3 months, the single-treatment success and stone-free rates were 25.0% and 9.1%, respectively. The overall treatment success rate at 3 months was 63.6%, and the stone-free rate was 39.1%. Little incremental benefit was found for more than two SWL treatments per stone. The auxiliary treatment rate was 72.7%, with an efficiency quotient of 10.5%. On multivariate analysis, stone burden (p = 0.074), other calyceal location (p = 0.026), and body mass index (p = 0.013) were found to be prognostic for SWL success. CONCLUSIONS: Patients with HSK appear to have lower success and stone-free rates after SWL than patients with normal kidneys. This likely has to do with factors such as greater skin-to-stone distance (particularly for calyceal stones) and restricted urinary drainage. SWL may be offered to patients with a HSK once limitations in stone clearance have been considered.

A comparison of treatment modalities for renal calculi between 100 and 300 mm2: are shockwave lithotripsy, ureteroscopy, and percutaneous nephrolithotomy equivalent?

BACKGROUND AND PURPOSE: Shockwave lithotripsy (SWL) is considered a standard treatment for patients with upper-tract stones that are less than 10 mm in diameter, whereas stones that are larger than 20 mm are best managed by percutaneous nephrolithotomy (PCNL). The management of stones between these sizes remains controversial. Our purpose was to review our contemporary series of SWL, ureteroscopy (URS), and PCNL outcomes for intermediate-sized upper tract calculi (100-300 mm(2)). PATIENTS AND METHODS: Analysis was restricted to those patients who were treated for a renal calculus that measured between 100 and 300 mm(2) during a 4-year span. Demographic, stone, patient, treatment, and follow-up data were collected from a prospectively maintained database. RESULTS: A total of 137 patients were referred with nonstaghorn calculi with an area between 100 and 300 mm(2). Fifty-three (38.7%) patients were treated with SWL, while 41 (29.9%) and 43 (31.4%) underwent ureteroscopy and PCNL, respectively. Mean stone area was higher in the PCNL group (P < 0.001), whereas stone density was higher for patients undergoing SWL (P = 0.002). Single treatment success rates were better for PCNL at 95.3%,vs 87.8% for ureteroscopy and 60.4% for SWL, P < 0.001. When allowing for two SWL treatments, the success rate improved to 79.2%, thus equalizing the success of the three treatment modalities (P = 0.66). Auxiliary treatments were more common after SWL (42.3%; P < 0.01). CONCLUSIONS: For intermediate-sized upper-tract stones, when allowing for up to two SWL treatments, there was no significant difference between treatment modalities. Thus, SWL is a reasonably successful treatment alternative for patients who are not fit for a general anesthetic or who prefer SWL over competing treatments, provided they accept a potentially higher number of treatments.

Comparison of supracostal versus infracostal percutaneous nephrolithotomy using the novel prone-flexed patient position.

BACKGROUND AND PURPOSE: Percutaneous nephrolithotomy (PCNL) is considered standard therapy for large and complex renal calculi. The optimal patient position and puncture site for collecting system access remains controversial. This purpose of this retrospective review is to analyze our PCNL series with respect to puncture tracts, success, and complications using our novel prone-flexed position. PATIENTS AND METHODS: Perioperative data were collected on consecutive PCNL cases for renal calculi performed in the prone-flexed position from 2004 to 2009. Patient demographic, stone, operative, postoperative, and follow-up data were collected. Successful treatment was defined as stone free or sandlike (≤1 mm) particles visible on CT scan at 3 months. RESULTS: A total of 318 patients, with a mean age of 52.9 years and body mass index of 27.8 kg/m(2), underwent PCNL in the prone-flexed position (57.9% male). Sixteen tracts were above the 11th rib, 138 were above the 12th rib, and 164 were infracostal. Multiple tracts were used in 16 patients. There were no significant differences between patients undergoing supracostal vs infracostal puncture with respect to side, stone area, number of tracts, number of stones, or the presence of staghorn or struvite calculi. Success in the supracostal group (89.8%) was not statistically different from the infracostal group (94.1%), P>0.05. Overall complication rates across groups was low (11.6%), with a significant difference in complications between the supracostal and infracostal puncture groups across Clavien grades, P<0.01. No patients needed blood transfusions or angioembolization. CONCLUSION: Regardless of supracostal or infracostal renal access, our novel prone-flexed position assists with percutaneous renal access and ease of nephrolithotomy, while maintaining excellent success rates and minimizing procedural morbidity.

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.

Shock wave lithotripsy: a randomized, double-blind trial to compare immediate versus delayed voltage escalation.

OBJECTIVES: To present a randomized trial investigating immediate vs delayed voltage escalation during shock wave lithotripsy (SWL). SWL efficiency is affected by the energy setting of the lithotripter, the consumption level of the electrode, and the rate of shock wave administration. Preliminary data have suggested that delaying voltage escalation for SWL might both improve fragmentation and minimize renal injury. METHODS: A total of 160 patients with previously untreated radiopaque renal calculi were randomized to undergo immediate vs delayed voltage escalation SWL. Success was defined as an asymptomatic patient who was stone free or had adequate fragmentation (sand or fragments < or = 4 mm) at 3 months after treatment. RESULTS: Of the 160 patients, 83 were treated with immediate voltage escalation SWL and 77 patients with delayed escalation. The groups were similar in sex, body mass index, stone area, and stone location. The overall success rate at 3 months was 72.5% for immediate vs 54.5% for delayed SWL (P = .021). After adjusting for body mass index, sex, and stone location, the stone area decreased more rapidly in patients treated with immediate voltage escalation (P = .002). A trend was also seen for immediate voltage escalation to be more effective in the treatment of smaller calculi with a cross-sectional area of < 100 mm(2) (P = .089) compared with calculi with a cross-sectional area of > or = 100 mm(2) (P = .248). No differences were seen in the complications or ancillary procedures between the 2 treatments (P = .667 and P = .355, respectively). No perinephric hematomas were observed in either group. CONCLUSIONS: These results suggest that delayed voltage escalation might not provide superior stone fragmentation compared with conventional, immediate voltage escalation.