Treatment of contralateral hydrocele in neonatal testicular torsion: Is less more?

OBJECTIVE: Treatment of neonatal testicular torsion has two objectives: salvage of the involved testicle (which is rarely achieved) and preservation of the contralateral gonad. The second goal universally involves contralateral testicular scrotal fixation to prevent the future occurrence of contralateral torsion. However, there is controversy with regards to management of a synchronous contralateral hydrocele. It has been our policy not to address the contralateral hydrocele through an inguinal incision to minimize potential injury to the spermatic cord. Our objective in this study was to determine whether the decision to manage a contralateral hydrocele in cases of neonatal testicular torsion solely through a scrotal approach is safe and effective. PATIENTS AND METHOD: We reviewed all cases of neonatal testicular torsion occurring at our institution between the years 1999 and 2006. Age at presentation, physical examination, ultrasonographic and intraoperative findings were recorded. Patients were followed after initial surgical intervention to determine the likelihood of developing a subsequent hydrocele or hernia. RESULTS: Thirty-seven patients were identified as presenting with neonatal torsion. Age of presentation averaged 3.5 days (range 1-14 days). Left-sided pathology was seen more commonly than the right, with a 25:12 distribution. All torsed testicles were nonviable. Twenty-two patients were noted to have a contralateral hydrocele at presentation. All hydroceles were opened through a scrotal approach at the time of contralateral scrotal fixation. No patient underwent an inguinal exploration to examine for a patent process vaginalis. None of the patients who presented with a hydrocele have developed a clinical hydrocele or hernia after an average 7.5 years (range 4.3-11.2) follow-up. CONCLUSION: We have demonstrated that approaching a contralateral hydrocele in cases of neonatal testicular torsion solely through a scrotal incision is safe and effective. Inguinal exploration was not performed in our study and our long-term results demonstrate that such an approach would have brought no additional benefit. In avoiding an inguinal approach we did not subject our patients to unnecessary risk of testicular or vasal injury. Contralateral hydrocele is commonly seen in cases of neonatal testicular torsion. In our experience this is a condition of minimal clinical significance and does not warrant formal inguinal exploration for treatment. This conservative management strategy minimizes the potential of contralateral spermatic cord injury in the neonate. The aims of the study were met.

Validation of a bowel dysfunction instrument for adolescents with spina bifida.

INTRODUCTION: Existing survey instruments for bowel dysfunction in the pediatric population are either parent-reported or focus on non-neurogenic bowel dysfunction. OBJECTIVE: The purpose of this study was to develop and validate an adolescent-reported survey to assess the severity of bowel dysfunction in spina bifida patients and examine its impact on quality of life (QOL). STUDY DESIGN: We performed a cross-sectional study of patients in our Myelodysplasia Program, aged 11-17 years, with a history of constipation and/or fecal incontinence (FI) from November 2010 to June 2013. Control patients, aged 11-17 years, were recruited from the stone clinic. Exclusion criteria were lack of English fluency, insufficient reading skills, or an incontinent fecal diversion. A 29-item version of the Adolescent Fecal Incontinence and Constipation Symptom Index (A-FICSI) was developed with five domains (Figure). Test re-test reliability and correlation with the total global health-related QOL score from the Parkin survey were measured using the Pearson correlation coefficient. A factor analysis model with four-fold correlations was tested. RESULTS: Of the 65 study-eligible individuals approached, 25 (11 boys) completed the A-FICSI (median age 12.6 years, IQR 11.8-14.7 years) and 17 completed another survey on urinary incontinence (64.6% response rate). Twenty-one control patients with nephrolithiasis completed the A-FICSI. Nine of the 25 completed a second administration of the survey. The mean correlation between repeated administrations of the survey was r = 0.43. There was a significant negative correlation between severity of constipation (r = -0.299, p < 0.05) and severity of FI (r = -0.316, p < 0.05) with the total Parkin QOL score. The Comparative Fit Index (CFI) was 0.864. Most items loaded significantly on their respective factors. Between-factor correlations were all significant (>0.30) in the predicted direction. Unstandardized residuals were 8.7% (95% CI 6.4-10.9%). Item reduction was performed on the 29-item instrument based on results of the factor analysis. The finalized instrument contained 21 items. DISCUSSION: This is the first adolescent-reported bowel dysfunction instrument to undergo formal psychometric assessment in the spina bifida population. The instrument demonstrated adequate reliability and the five-factor structure fit the data well. This study highlights the negative impact of bowel dysfunction on the QOL of spina bifida patients. It is limited by the moderate sample size that is a common issue in relatively rare diseases. CONCLUSION: The A-FICSI possesses desirable psychometric properties for the measurement of bowel dysfunction in the spina bifida population.

Long-term outcomes of catheterizable continent urinary channels: What do you use, where you put it, and does it matter?

INTRODUCTION: Appendicovesicostomy (APV) and Monti ileovesicostomy (Monti) are commonly used catheterizable channels with similar outcomes on short-term follow-up. Their relative long-term results have not been previously published. OBJECTIVE: Our goal was to assess long-term durability of APV and Monti channels in a large patient cohort. STUDY DESIGN: In this retrospective cohort study, we retrospectively reviewed consecutive patients ≤21 years old undergoing APV and Monti surgery at our institution (1990-2013). We collected data on demographics, channel type, location, continence and stomal and subfascial revisions. Kaplan-Meier survival and Cox proportional hazards analysis were used. RESULTS: Of 510 patients meeting inclusion criteria, 214 patients had an APV and 296 had a Monti (50.5% spiral Monti). Median age at surgery was 7.4 years for APV (median follow-up: 5.7 years) and 8.7 years for Monti (follow-up: 7.7 years). Stomal stenosis, overall stomal revisions and channel continence were similar for APV and Monti (p ≥ 0.26). Fourteen APVs (6.5%) had subfascial revisions compared to 49 Montis (16.6%, p = 0.001). On survival analysis, subfascial revision risk at 10 years for APV was 8.6%, Monti channels excluding spiral umbilical Monti: 15.5% and spiral umbilical Monti: 32.3% (p < 0.0001, Figure). On multivariate regression, Monti was 2.09 times more likely than APV to undergo revision (p = 0.03). The spiral Monti to the umbilicus, in particular, was 4.23 times more likely than APV to undergo revision (p < 0.001). Concomitant surgery, gender, age and surgery date were not significant predictors of subfascial revision (p ≥ 0.17). Stomal location was significant only for spiral Montis. DISCUSSION: Our study has several limitations. Although controlling for surgery date was a limited way of adjusting for changing surgical techniques, residual confounding by surgical technique is unlikely, as channel implantation technique was typically unrelated to channel type. We did not include complications managed conservatively or endoscopically. In addition, while we did not capture patients who were lost to follow-up, we attempted to control for this through survival analysis. CONCLUSIONS: We demonstrate, durable long-term results with the APV and Monti techniques. The risk of channel complications continues over the channel's lifetime, with no difference in stomal complications between channels. At 10 years after initial surgery, Monti channels were twice as likely to undergo a subfascial revision (1 in 6) than APV (1 in 12). The risk is even higher in for the spiral umbilical Monti (1 in 3).

Urinary incontinence in spina bifida: Initial instrument validation.

The purpose of this study was to perform a psychometric assessment of the Incontinence Symptom Index-Pediatric (ISI-P) in a cohort of adolescents with spina bifida (SB) and neuropathic urinary incontinence (UI) to test its validity and reliability. The ISI-P, an 11-item instrument with domains for symptom severity and impairment, was self-administered by subjects 11-17 years old with SB and UI. Controls were 11-17 years old, with nephrolithiasis and no history of UI. Formal psychometric assessment included an evaluation of internal consistency, test re-test reliability and factor analysis. Of 78 study-eligible subjects we attempted to contact, 33 (66.7% female) with a median age of 13.1 years completed the ISI-P (42.3% response rate). 21 control patients also completed the ISI-P. Cronbach's alpha was 0.936 and 0.792 for the severity and bother factors respectively. The delta Chi-square test for the two-factor (vs. one-factor) model was significantly [χ(2)(89) = 107.823, p < 0.05] in favor of the former model with descriptive fit indices being excellent (e.g., comparative fit index = 0.969). Furthermore, category information analysis showed that all categories were associated with different threshold values, namely that each category contributed unique information for the measurement of the latent trait. In conclusion, the ISI-P has desirable psychometric properties for the measurement of UI symptom severity and impairment in adolescents with SB.

Long-term renal functional outcomes after primary gastrocystoplasty.

PURPOSE: We assessed long-term renal function, morbidities and mortality in 50 patients who had undergone primary gastrocystoplasty at our institution. MATERIALS AND METHODS: We retrospectively reviewed patients 21 years or younger who had undergone primary gastrocystoplasty between 1984 and 2004. Patients who underwent secondary gastrocystoplasty or primary composite augmentation or had cloacal exstrophy were excluded. Primary outcome was progression to end-stage renal disease. Secondary outcomes included mortality, bladder malignancy, hematuria-dysuria syndrome, electrolyte abnormalities and surgical revisions. RESULTS: Of 50 patients who had undergone gastrocystoplasty 35 met inclusion criteria. Median age was 9.4 years and 60% of the patients were male. Median followup was 19 years (IQR 11 to 25). Of the 35 patients 15 (43%) had normal preoperative estimated glomerular filtration rate and 5 (14%) had stage 2, 10 (29%) stage 3 and 5 (14%) stage 4 chronic kidney disease. Five of the 15 patients with stage 3 or 4 chronic kidney disease improved to normal estimated glomerular filtration rate, 1 remained with stage 3 disease and 9 progressed to end-stage renal disease. In 1 patient with normal estimated glomerular filtration rate end-stage renal disease developed following an episode of septic shock due to osteomyelitis. Seven patients in the cohort (20%) died, with 1 each dying of ventriculoperitoneal shunt infection, pneumonia, end-stage renal disease, complications of pregnancy and unknown cause, and 2 patients dying of septic shock due to urinary tract infection. There were no bladder malignancies. Hematuria-dysuria syndrome developed in 9 patients (24%). Eight patients (23%) underwent surgical revision. CONCLUSIONS: The majority of patients had preserved or improved renal function after gastrocystoplasty. There were no deaths attributable to gastric augmentation and no bladder malignancies. Approximately a fourth of patients required surgical revision.

New contralateral vesicoureteral reflux after unilateral ureteral reimplantation: predictive factors and clinical outcomes.

PURPOSE: Although unilateral ureteral reimplantation for vesicoureteral reflux is highly successful, new contralateral reflux will develop postoperatively in some patients. We examined predictors and clinical outcomes of postoperative contralateral vesicoureteral reflux. MATERIALS AND METHODS: We reviewed patients who underwent nontapered unilateral reimplantation for primary vesicoureteral reflux graded on a 3-point scale at our institution from January 1990 to December 2002, and identified those with subsequent contralateral vesicoureteral reflux. We analyzed the association of patient/procedure characteristics with incidence, and time to resolution of contralateral reflux and postoperative urinary tract infection. Multivariable models controlled for variables associated with incidence and time to resolution of contralateral reflux. RESULTS: A total of 395 patients (77.2% female, median age 5.3 years) underwent ureteral reimplantation for vesicoureteral reflux. Preoperative reflux was grade 1 in 2.8% of patients, grade 2 in 56.6% and grade 3 in 40.6%. Technical success was 95.4%. After reimplantation 39 patients (9.9%) had new contralateral reflux (grade 1 in 7, grade 2 in 27 and grade 3 in 5). Median followup was 51.8 months. On multivariate analysis younger age (less than 6 years, OR 3.7, p = 0.006) and low observed bladder capacity as percent of predicted bladder capacity (less than 50% of predicted capacity, OR 6.3, p = 0.02) were significant predictors of contralateral reflux. Contralateral reflux resolved in 21 of 27 patients (77.8%) on subsequent cystography at a median of 21.5 months. Two patients underwent reimplantation for persistent contralateral reflux. Four of 39 patients (10.3%) with contralateral reflux had postoperative febrile urinary tract infections at a median of 26 months, with spontaneous resolution of contralateral reflux in all. CONCLUSIONS: Younger patients and those with low observed vs predicted bladder capacity may be at increased risk for postoperative contralateral vesicoureteral reflux. A majority of contralateral reflux will resolve spontaneously, and the clinical course is typically benign.

Trends in revision circumcision at pediatric hospitals.

BACKGROUND: We sought to determine the incidence of revision circumcision at freestanding children's hospitals, and examine trends over time. METHODS: We searched the Pediatric Health Information Systems database to identify boys undergoing revision circumcision (RC), primary non-newborn circumcision (PC), or lysis of penile adhesions (LPA) from 2004 to 2009. Rates of RC procedures were calculated by dividing the incidence of procedures by the total male ambulatory surgical volume. RESULTS: We identified 34,568 patients of whom 5632 underwent RC, 25,768 PC, and 3168 LPA. The rate of RC increased 119%, which was significantly more than PC (19%; P<.001) or LPA (37%; P<.001). Urologists performed 76% of RC and 12% were performed with other genitourinary procedures. Boys undergoing RC were predominately white (60%) and publicly insured (61%). CONCLUSIONS: There was a disproportionate increased rate of RC performed at Pediatric Health Information Systems hospitals compared with PC or LPA. Wide variation exists in rate increases among hospitals.

Long-term incidence of urinary tract infection after ureteral reimplantation for primary vesicoureteral reflux.

OBJECTIVE: To determine the incidence of urinary tract infection (UTI) after ureteral reimplantation (UR) for primary vesicoureteral reflux (VUR). MATERIALS AND METHODS: In this retrospective review, the pyelonephritis-free survival of patients with primary VUR who underwent open UR from January 1990 to December 2002 was assessed using a Cox proportional hazards analysis. RESULTS: 1076 patients underwent open UR for primary VUR. 73.0% were female; median age was 4.7 years. 80.1% presented with UTI. Clinical success rate for non-tapered UR was 96.5%. Median follow-up was 2.9 years. 21.8% had at least one postoperative UTI. 6.5% had postoperative pyelonephritis (POP) at a median of 21 months postoperatively. On multivariate survival analysis female gender (OR 9.97, 95% CI 3.07-32.34), preoperative VUR grade ≥ 3 (2.14, 1.25-3.69), breakthrough preoperative UTI (2.00, 1.22-3.25), and preoperative renal scarring (1.86, 1.15-2.99) were associated with POP. CONCLUSION: POP is rare on long-term follow-up, suggesting that UR is effective in reducing pyelonephritis in this population.

Clinical outcomes and long-term resolution in patients with persistent vesicoureteral reflux after open ureteral reimplantation.

PURPOSE: Success rates of ureteral reimplantation for primary vesicoureteral reflux are high. Few studies document the natural history of children with persistent vesicoureteral reflux. We reviewed their clinical outcomes and long-term resolution. MATERIALS AND METHODS: We performed a retrospective review of all children with persistent vesicoureteral reflux (grade 1 or greater) into the reimplanted ureter(s) on initial cystogram after reimplantation for primary vesicoureteral reflux at our institution from January 1990 to December 2002. We evaluated subsequent cystograms (graded on the 3-point radionuclide cystogram scale), surgery and urinary tract infection. We performed survival analyses of time to resolution of persistent (grade 1 or greater) and clinically significant (grade 2 or greater) vesicoureteral reflux in patients with more than 1 postoperative cystogram. RESULTS: Of 965 patients 59 (94 ureters) had persistent vesicoureteral reflux (6.1%), including 19 grade 1/3, 29 grade 2/3 and 11 grade 3/3. Median patient age at reimplantation was 1.9 years (range 0.8 to 5.1) and 62.7% were female. Preoperative vesicoureteral reflux grade was 2/3 in 42.4% and 3/3 in 57.6%, and 30.5% of patients had ureteral tapering. Median followup was 47.1 months (IQR 19.3-650.3). Reflux was resolved in 26 of 36 (72.2%) patients and median time to resolution was 20.4 months. Grade 2 or greater reflux on postoperative cystogram resolved in 21 of 32 (65.6%) patients and median time to resolution was 20.4 months. There were 10 patients with persistent vesicoureteral reflux at last cystogram, grade 1 or 2 in 9 and 3/3 in 1 patient. One patient underwent repeat reimplantation for persistent vesicoureteral reflux and 7 (13%) had postoperative febrile urinary tract infection at a median of 37 months postoperatively (IQR 1.7-64.4). CONCLUSIONS: Persistent vesicoureteral reflux after reimplantation resolves spontaneously in most children and can be managed nonoperatively with good long-term outcomes.

Association of urolithiasis with systemic conditions among pediatric patients at children's hospitals.

PURPOSE: Urolithiasis is associated with systemic medical conditions in adults but associations have not been well studied in children. We investigated the association of urolithiasis with diabetes mellitus, hypertension and obesity among children with and without urolithiasis. MATERIALS AND METHODS: We performed a matched case-control study using the PHIS (Pediatric Health Information System) database. ICD-9 codes identified urolithiasis cases from 2004 to 2009. Four randomly selected controls were matched by age, hospital, patient care setting and year of treatment. Diagnoses from all hospital encounters were ascertained for comorbid conditions. Univariate and multivariable conditional logistic regression was used to assess the associations of urolithiasis with diabetes mellitus, hypertension and obesity. RESULTS: We identified 9,843 urolithiasis cases and 39,047 controls. On univariate analysis stone formers had significantly higher odds of obesity (OR 1.44, 95% CI 1.27-1.64) and hypertension (OR 2.12, 95% CI 1.88-2.40) compared to controls. The odds of type I diabetes mellitus was lower among cases compared to controls (OR 0.38, 95% CI 0.30-0.48). After adjusting for gender, race, insurance type and number of visits using logistic regression, children with urolithiasis still had higher odds of obesity (AOR 1.30, 95% CI 1.12-1.51) and hypertension (AOR 1.61, 95% CI 1.40-1.86) as well as lower odds of type I diabetes mellitus (AOR 0.32, 95% CI 0.25-0.41) compared to controls. CONCLUSIONS: Among pediatric patients at freestanding children's hospitals, urolithiasis is associated with higher odds of obesity and hypertension and lower odds of type I diabetes mellitus. These findings may be helpful in further elucidating the etiology of pediatric urolithiasis.

Durability of antireflux effect of ureteral reimplantation for primary vesicoureteral reflux: findings on long-term cystography.

OBJECTIVE: To evaluate the long-term durability of successful ureteral reimplantation (UR) for vesicoureteral reflux (VUR) through a review of late cystography (LC) findings. MATERIALS AND METHODS: We performed a retrospective chart review of all children with primary VUR who underwent successful open UR (grade 0 VUR into the reimplanted ureter[s] on initial cystogram) at our institution from January 1990 to December 2002. We identified successful UR patients who underwent LC ≥ 1 year after UR and reviewed the results for the presence of recurrent VUR into the reimplanted ureter(s). RESULTS: Seven-hundred ninety-four patients underwent successful open UR for primary VUR, of whom 60 (7.6%) had a subsequent LC. Preoperative VUR grade was ≤ II in 20 (34.5%) and ≥ III in 38 (65.5%). Median age at UR was 3.5 years (IQR 1.3-6.2 years); 51 (85%) were female. UR was intravesical in 45 (75%) and bilateral in 19 (32%). LC was performed at a median of 38.7 months after UR (IQR 19.6-66.1 months). Indication for LC was febrile urinary tract infection (UTI) in 16 (27%), nonfebrile UTIs in 15 (25%), follow-up of contralateral VUR in 16 (27%), and other clinical indications in 13 (21%). The recurrence rate was 0%; of the 79 reimplanted ureters, 100% (95% CI 95.4-100) had no VUR (grade 0). CONCLUSION: Among children who underwent successful open UR for primary VUR, there was no VUR recurrence on extended follow-up. This suggests that the late durability of open antireflux surgery is excellent.

Racial variation in timing of pyeloplasty: prenatal versus postnatal diagnosis.

PURPOSE: We have previously shown that nonwhite patients with ureteropelvic junction obstruction undergo pyeloplasty at a younger age than white patients. The mechanisms behind this finding are unclear, since there is no known racial variation in the natural history of ureteropelvic junction obstruction. We used a detailed clinical database to explain this phenomenon. MATERIALS AND METHODS: We retrospectively reviewed all patients undergoing primary pyeloplasty at our institution between 1992 and 2008. More than 360 data points were abstracted for each patient, including self-reported race, socioeconomic status, symptom duration and presentation. RESULTS: Of 847 patients undergoing pyeloplasty during the study period 741 met inclusion criteria. Nonwhite patients underwent surgery at a younger age (0.6 years) than whites (2.6 years, p <0.0001). When stratified by timing of clinical presentation (prenatal vs postnatal), there was no significant difference in race among patients presenting prenatally (0.37 vs 0.36 years, p = 0.22). Nonwhite patients presenting postnatally were significantly younger than white patients (6.3 vs 8.2 years, p = 0.03). This finding appeared to be due to differences in age at initial clinical presentation (5.4 vs 7.0 years, p = 0.03) and in time from initial clinical presentation to urological evaluation (0.6 vs 3.2 months, p = 0.03). These differences persisted after correcting for other factors, including markers of socioeconomic status. CONCLUSIONS: Consistent with previous studies, we found that nonwhite patients underwent primary pyeloplasty at a younger age than whites. This difference is limited to patients presenting after birth. Prenatally diagnosed patients underwent surgery at similar ages regardless of race.

Retrograde ureteral access after cross-trigonal ureteral reimplantation: A straightforward technique.

PURPOSE: Retrograde ureteral access after cross-trigonal ureteral reimplantation can be challenging. We present our experience with percutaneous retrograde ureteral catheterization, status post cross-trigonal ureteral reimplantation. MATERIALS AND METHODS: We evaluated all patients who underwent attempted percutaneous retrograde ureteral catheterization after cross-trigonal ureteral reimplantation. All clinical data, radiographic images and operative reports were reviewed. Ureteral access was obtained by percutaneously entering the bladder with an intravenous needle/catheter under cystoscopic guidance. The needle was then removed leaving the catheter in place. The ureteral orifice was then accessed through the intravenous catheter by a ureteral access wire and/or ureteral catheter under cystoscopic guidance. RESULTS: From 1978 to 2008, 13 patients (11 boys and 2 girls) with a history of cross-trigonal ureteral reimplantation underwent percutaneous retrograde ureteral catheterization. The procedure was unilateral in 12 patients and bilateral in one. Indications for the procedure included: retrograde pyelography and double-J stent insertion for ureteropelvic junction or ureterovesical junction obstruction (10); removal of migrated stent (2); and treatment of a ureteral stone (1). The procedure was performed successfully in all patients and without complications. CONCLUSIONS: Percutaneous retrograde ureteral catheterization is a safe, straightforward, and effective modality for obtaining retrograde ureteral access in children, status post cross-trigonal ureteral reimplantation.

Evaluation of pediatric nephrolithiasis.

Nephrolithiasis in the pediatric population is an important cause of morbidity worldwide. Presenting signs and symptoms are often considerably different from those in adults. Vague abdominal pain, hematuria, and urinary tract infection are more common in children than the classic colicky flank pain. Imaging of suspected cases should be undertaken with careful consideration of diagnostic accuracy and the potentially harmful effects of ionizing radiation. Because children with nephrolithiasis have a high chance of recurrent stone formation, a thorough risk assessment and metabolic evaluation should be performed. This review discusses the presentation, acute evaluation and risk assessment of nephrolithiasis in the pediatric population.

Clinical and magnetic resonance imaging characteristics of vaginal and paraurethral leiomyomas: can they be diagnosed before surgery?

OBJECTIVE: To describe the clinical and magnetic resonance imaging (MRI) characteristics of vaginal and paraurethral leiomyomas. PATIENTS AND METHODS: All patients with pathologically confirmed paraurethral and vaginal wall leiomyomas from January 2006 to August 2007 were reviewed. Patients with no preoperative MRI of the pelvis were excluded. RESULTS: Five patients were identified; all had a firm, smooth, non-tender, non-fluctuant mass. MRI showed a well-circumscribed shape, a homogeneous signal that was hypointense or isointense to muscle on T1- and hyperintense or isointense to muscle on T2-weighted images, and uniform enhancement. In all cases, MRI excluded urethral diverticulae, and pathology showed leiomyoma, of which one had atypical features. CONCLUSION: Paraurethral and vaginal wall leiomyomas can be identified before surgery with a reasonable degree of certainty, based on their clinical and MRI characteristics.

Charlson comorbidity index and success of extracorporeal shock wave lithotripsy.

INTRODUCTION/OBJECTIVE: We examined the potential correlation between Charlson comorbidity index (CCI) and stone free rate after extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: Two hundred twenty-six adult patients were treated with 241 ESWL procedures for a renal or ureteral stone(s) over a 3 year period. Age, race, comorbidities, CCI, stone size and location, number of shocks and power level were determined. Treatment efficacies were evaluated at a mean of 56.1 days after each ESWL with computed tomography, abdominal x-ray, intravenous pyleography and/or renal ultrasound. Multivariate logistic regression analysis was performed. RESULTS: There was no correlation between CCI and any of the following: stone burden, number of shocks, or power level. There was no difference in stone burden, number of shocks or power level between those who were and were not stone free. Stone free rates for patients with CCI of zero, one, and two or greater were 44.7% (71/159), 27% (13/48) and 41.2% (14/34) respectively. Patients with an index of one were 2.1 times more likely to have a residual stone burden than patients with an index of zero (95% CI 0.99-4.42, p = 0.05). Patients with one comorbidity were 2.4 times more likely to have a residual stone burden than patients with none (95% CI 1.04-5.72, p = 0.04). Patients with upper ureteral stones were less likely to have a residual stone burden than patients with renal stones (RR = 0.52, 95% CI 0.27-0.98, p = 0.04). Those with lower ureteral stones were less likely to have a residual stone burden than those with renal stones (RR = 0.20, 95% CI 0.09-0.43, p <0.0001). The only significant predictors of the stone free rate were stone location and number of comorbidities. CONCLUSIONS: Stone location and number of comorbidities were significant predictors of ESWL outcome. The CCI may underestimate the magnitude of comorbidities and their effect on stone treatment efficacy.