Ureteral Strictures Following Ureteroscopy for Kidney Stone Disease: A Population-based Assessment.

PURPOSE: As the prevalence of urolithiasis increases and ureteroscopy is used more frequently, the risks of uncommon complications such as ureteral stricture may become more notable. Our objective is to assess the rate and associated risk factors of ureteral stricture formation in patients undergoing ureteroscopy. MATERIALS AND METHODS: Utilizing the IBM MarketScan research database, we evaluated data from 2008 to 2019 and compared ureteral stricture rates and their management following ureteroscopy to subjects who had shock wave lithotripsy. Shock wave lithotripsy was used as a comparison group to represent the rate of stricture from stone disease alone. A third group of those having both shock wave lithotripsy and ureteroscopy was included. Patients and secondary procedures were identified using Current Procedural Terminology, and International Classification of Diseases-9 and -10 codes. RESULTS: A total of 329,776 patients received ureteroscopy, shock wave lithotripsy, or shock wave lithotripsy+ureteroscopy between 2008 and 2019. Stricture developed in 2.9% of patients after ureteroscopy, 1.5% after shock wave lithotripsy, and 2.6% after shock wave lithotripsy+ureteroscopy. In the multivariable model, rates of stricture were 1.7-fold higher after ureteroscopy vs shock wave lithotripsy (OR:1.71, 95% CI 1.62-1.81). Preoperative hydronephrosis, age, prior stones/intervention, and concurrent kidney and ureteral stones were associated with increased risk of stricture. Of those with strictures incurred after ureteroscopy, 35% required drainage, 21% had endoscopic intervention, 4.8% required reconstructive surgery, and 1.7% underwent nephrectomy. CONCLUSIONS: Ureteral stricture rate after ureteroscopy of nearly 3% was higher than expected and approximately twice the rate attributable to stone disease alone. Factors associated with the stone as well as instrumentation were found to be risk factors. The morbidity of stricture disease following ureteroscopy was significant.

Impact of radiation on the incidence and management of ureteroenteric strictures: a contemporary single center analysis.

BACKGROUND: Ureteroenteric stricture incidence has been reported as high as 20% after urinary diversion. Many patients have undergone prior radiotherapy for prostate, urothelial, colorectal, or gynecologic malignancy. We sought to evaluate the differences between ureteroenteric stricture occurrence between patients who had radiation prior to urinary diversion and those who did not. METHODS: An IRB-approved cystectomy database was utilized to identify ureteroenteric strictures among 215 patients who underwent urinary diversion at a single academic center between 2016 and 2020. Chart abstraction was conducted to determine the presence of confirmed stricture in these patients, defined as endoscopic diagnosis or definitive imaging findings. Strictures due to malignant ureteral recurrence were excluded (3 patients). Statistical analysis was performed using chi squared test, t-test, and Wilcoxon Rank-Sum Test, logistic regression, and Kaplan-Meier analysis of stricture by cancer type. RESULTS: 65 patients had radiation prior to urinary diversion; 150 patients did not have a history of radiation therapy. Benign ureteroenteric stricture rate was 5.3% (8/150) in the non-radiated cohort and 23% (15/65) in the radiated cohort (p = < 0.001). Initial management of stricture was percutaneous nephrostomy (PCN) in 78% (18/23) and the remaining 22% (5/23) were managed with primary retrograde ureteral stent placement. Long term management included ureteral reimplantation in 30.4% (7/23). CONCLUSIONS: Our study demonstrates a significant increase in rate of ureteroenteric strictures in radiated patients as compared to non-radiated patients. The insult of radiation on the ureteral microvascular supply is likely implicated in the cause of these strictures. Further study is needed to optimize surgical approach such as utilization of fluorescence angiography for open and robotic approaches.

Propensity-Weighted Comparison of Long-Term Risk of Urinary Adverse Events in Elderly Women Treated For Cervical Cancer.

PURPOSE: Cervical cancer treatment is associated with a risk of urinary adverse events (UAEs) such as ureteral stricture and vesicovaginal fistula. We sought to measure the long-term UAE risk after surgery and radiation therapy (RT), with confounding controlled through propensity-weighted models. METHODS AND MATERIALS: From the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, we identified women ≥66 years old with nonmetastatic cervical cancer treated with simple surgery (SS), radical hysterectomy (RH), external beam RT plus brachytherapy (EBRT+BT), or RT+surgery. We matched them to noncancer controls 1:3. Differences in demographic and cancer characteristics were balanced by propensity weighting. Grade 3 to 4 UAEs were identified by diagnosis codes plus treatment codes. Cumulative incidence was measured using Kaplan-Meier methods. The hazard associated with different cancer treatments was compared using Cox models. RESULTS: UAEs occurred in 272 of 1808 cases (17%) and 222 of 5424 (4%) controls; most (62%) were ureteral strictures. The raw cumulative incidence of UAEs was highest in advanced cancers. UAEs occurred in 31% of patients after EBRT+BT, 25% of patients after RT+surgery, and 15% of patients after RH; however, after propensity weighting, the incidence was similar. In adjusted Cox models (reference = controls), the UAE risk was highest after RT+surgery (hazard ratio [HR], 5.07; 95% confidence interval [CI], 2.32-11.07), followed by EBRT+BT (HR, 3.33; 95% CI, 1.45-7.65), RH (HR, 3.65; 95% CI, 1.41-9.46) and SS (HR, 0.99; 95% CI, 0.32-3.01). The higher risk after RT+surgery versus EBRT+BT was statistically significant, whereas, EBRT+BT and RH were not significantly different from each other. CONCLUSIONS: UAEs are common after cervical cancer treatment, particularly in patients with advanced cancers. UAEs are more common after RT, but these women tend to have the advanced cancers. After propensity weighting, the risk after RT was similar to that after surgery.

Downstream complications following urinary diversion.

PURPOSE: Surveillance following urinary diversion should be tailored to capture complications downstream from the initial reconstruction. Most analyses of the morbidity associated with urinary diversion are restricted to the index admission or the immediate postoperative period. We characterize the long-term medical and surgical complications and burden of health care use after urinary diversion. MATERIALS AND METHODS: Using the 5% Medicare sample from 1998 to 2005 we identified individuals who underwent cutaneous and orthotopic continent urinary diversion, ileal conduit or other types of diversion including enterocystoplasty from physician claims for the index admission. We restricted our sample to subjects with claims 1 year before surgery and at least 2 years after the diversion. We included benign and malignant primary diagnoses, and evaluated the incidence of medical and surgical complications 2 and 5 years after surgery. We stratified complications by diversion type and compared long-term complications after urinary diversion surgery. RESULTS: Of the 1,565 subjects identified 80% underwent ileal conduit urinary diversion, 7% underwent cutaneous or orthotopic continent diversion and 13% underwent other types of reconstruction. Urinary stone formation, wound complications and fistula complications were more common following continent diversion 5 years after surgery, while ureteral obstruction and renal failure/impairment were more common after ileal conduit diversion. Overall we estimated that more than 16% of patients experienced renal failure or impairment after urinary diversion. CONCLUSIONS: Complications are common after urinary diversion and continue to occur through 5 years postoperatively. Urolithiasis and delayed wound complications appear to occur more commonly after continent diversion than after other urinary diversions. A large proportion of patients experience renal deterioration after diversion. These results highlight the need to survey patients for the diversion related complications of cystectomy as rigorously as we monitor for cancer recurrence.

Population-based comparison of laparoscopic and open pyeloplasty in paediatric pelvi-ureteric junction obstruction.

OBJECTIVE: To describe the extent of use and in-hospital outcomes of open and laparoscopic pyeloplasty for paediatric pelvi-ureteric junction (PUJ) obstruction in the USA. PATIENTS AND METHODS: Using the 2004-2008 Nationwide Inpatient Sample, we identified 4590 paediatric patients (≤18 years old) who underwent open or laparoscopic pyeloplasty for PUJ obstruction at 195 hospitals. Multivariable regression models were used to test the associations between hospital and patient covariates (age, gender, race, primary health insurance), type of admission (emergent vs elective), and hospital characteristics (teaching vs non-teaching status; rural vs urban location) with complications, length of stay (LOS), and total hospitalization costs. RESULTS: During the 5-year study interval, 4426 (96.4%) and 164 (3.6%) paediatric patients diagnosed with PUJ obstruction underwent open and laparoscopic pyeloplasty, respectively. The proportion of patients undergoing laparoscopic pyeloplasty gradually increased from 2.4% in 2004 to 4.4% in 2008, but this increase was not significant (P = 0.22 for trend). On multivariable analysis, laparoscopic pyeloplasty was observed to have rates of postoperative complications (2.51 vs 5.00; P = 0.67), LOS (2.42 vs 2.75; P = 0.33) and total hospitalization cost ($9755 vs $8537; P = 0.24) similar to those of open pyeloplasty. CONCLUSIONS: While laparoscopic pyeloplasty was generally an infrequent operation performed for paediatric PUJ obstruction during the period studied, this minimally invasive surgery provided similar outcomes in terms of in-hospital complications, LOS and total hospitalization costs. The results of this study inform policymakers about the comparative effectiveness of laparoscopic and open pyeloplasty.

Renal ultrasonography in the evaluation of acute kidney injury: developing a risk stratification framework.

BACKGROUND: In adult inpatients with acute kidney injury (AKI), clinicians routinely order a renal ultrasonography (RUS) study. It is unclear how often this test provides clinically useful information. METHODS: Cross-sectional study, including derivation and validation samples, of 997 US adults admitted to Yale-New Haven Hospital from January 2005 to May 2009, who were diagnosed as having AKI and who underwent RUS to evaluate elevated creatinine level. Pregnant women, renal transplant recipients, and patients with recently diagnosed hydronephrosis (HN) were excluded. Demographic and clinical characteristics were abstracted from the medical records. A multivariable logistic regression model was developed to create risk strata for HN and HN requiring an intervention (HNRI); a separate sample was used for validation. The frequency of incidental findings on RUS was assessed for each stratum. RESULTS: In a derivation sample of 200 patients, 7 factors were found to be associated with HN: history of HN; recurrent urinary tract infections; diagnosis consistent with obstruction; nonblack race; and absence of the following: exposure to nephrotoxic medications, congestive heart failure, or prerenal AKI. Among 797 patients in the validation sample (mean age, 65.6 years), 10.6% had HN and 3.3% had HNRI. Of 223 patients in the low-risk group, 7 (3.1%) had HN and 1 (0.4%) had HNRI (223 patients needed to be screened to find 1 case of HNRI). In this group, there were 0 incidental findings on RUS unknown to the clinical team. In the higher-risk group, 15.7% had HN and 4.7% had HNRI. CONCLUSION: In adult inpatients with AKI, specific factors can identify patients unlikely to have HN or HNRI on RUS.

Robotic pyeloplasty: a critical appraisal.

BACKGROUND: Laparoscopic pyeolplasty has become a minimally invasive alternative to open pyeloplasty. Due to technical concerns with intracorporeal suturing, robotic pyeloplasty has become an emerging alternative. METHODS: The literature was reviewed for reports and outcomes on robotic pyeloplasty. RESULTS: Reports of robotic pyeloplasty are increasing, and outcomes appear excellent. CONCLUSIONS: Robotic pyeloplasty is feasible with excellent outcomes. Challenges remain in making the procedure cost effective.

Ureteropelvic junction obstruction.

PURPOSE: We quantified the burden of ureteropelvic junction obstruction in the United States by identifying trends in the use of health care resources and estimating the economic impact of the disease. MATERIALS AND METHODS: The analytical methods used to generate these results were described previously. RESULTS: Inpatient hospitalization rates were highest in children younger than 3 years. Most patients were male and hospitalizations occurred almost exclusively at urban centers. Patients with a primary diagnosis of ureteropelvic junction obstruction between 1994 and 2000 had an overall decrease in the age adjusted rate of inpatient hospitalization from 1.1/100,000 to 0.8/100,000. Physician office visits by Medicare beneficiaries with ureteropelvic junction obstruction as the primary diagnosis showed stable overall age adjusted rates during the reported years. Between 1999 and 2003 mean inpatient length of stay and cost per child hospitalized with the primary diagnosis of ureteropelvic junction obstruction was 2.9 days and $7,728, respectively. Average length of stay decreased more for children than for adults but total inpatient spending remained stable at about $12 million. CONCLUSIONS: The majority of ureteropelvic junction obstructions are diagnosed in the perinatal period. Surgical intervention for pediatric patients has decreased with time, while there has been an increasing trend toward the conservative management of this condition.

Assessment of stricture formation with the ureteral access sheath.

OBJECTIVES: To analyze the long-term incidence of ureteral stricture formation in a series of patients in whom a new-generation ureteral access sheath was used. A new generation of ureteral access sheaths has been developed to facilitate ureteroscopic procedures. However, some have questioned their safety and whether the device might cause significant ureteral trauma. METHODS: Between September 1999 and July 2001, 150 consecutive ureteroscopic procedures with adjunctive use of an access sheath were performed. A retrospective chart review to April 2002 was done. Of the 150 patients, 130 underwent ureteroscopy for ureteral stones. Patients who underwent endoureterotomy or treatment of transitional cell carcinoma were excluded from this analysis. Sixty-two patients had follow-up greater than 3 months and were included in the analysis. Overall, 71 ureteroscopic procedures were performed, with 9 patients undergoing multiple procedures. Ninety-two percent of the patients had pathologic findings above the iliac vessels. The average patient age was 45.3 years (range 17 to 76), and 70% and 30% of the patients were male and female, respectively. The mean clinical follow-up was 332 days (range 95 to 821), and follow-up imaging was performed within 3 months after ureteroscopy in all patients. RESULTS: The 10/12F access sheath was used in 8 ureteroscopic procedures (11.2%), the 12/14F access sheath in 56 (78.9%), and the 14/16F access sheath in 7 (9.8%). One stricture was identified on follow-up imaging of 71 procedures performed, for an incidence of 1.4%. The patient developed the stricture at the ureteropelvic junction after multiple ureteroscopic procedures to manage recurrent struvite calculi. The access sheath did not appear to be a contributing factor. CONCLUSIONS: The results of our series indicate that the ureteral access sheath is safe and beneficial for routine use to facilitate flexible ureteroscopy. However, awareness of the potential ischemic effects with the use of unnecessarily large sheaths for long periods in patients at risk of ischemic injury should be considered. We advocate the routine use of the device for most flexible ureteroscopic procedures proximal to the iliac vessels.

Incidence and management of major urinary complications after pelvic exenteration for gynecological malignancies.

Urinary fistulae and obstruction following pelvic exenteration are frequent and life-threatening complications. They increase the mortality and morbidity rates of large exereses performed during pelvic exenteration for gynecological cancers. From a series of 97 patients who underwent pelvic exenteration for gynecological cancers we report the incidence, risk factors, and management of major urinary complications. Eighty patients had had previous surgery and/or pelvic radiation therapy at the time of pelvic exenteration. A urinary diversion was performed in 63 patients. Major early urinary complications were: urinary fistula in seven patients and ureteral obstruction in four patients (11.3% of the patients). Ten patients had a late urinary complication: stenosis of the cutaneous ureteral meatus (five), stenosis of the ureteroileal anastomosis following ileal loop (two), and urinary fistulae (three). Cancer recurrence was found in 4 of these 10 cases. Major early urinary complications were significantly increased in patients who had received previous pelvic radiation therapy (P < 0.05) and in patients who had had an intestinal conduit for urinary diversion (P < 0.05). Reoperation was done in six of seven cases of early urinary fistula (urinary undiversion four, nephrectomy one, ureteral reimplantation one). Three of four ureteral obstructions were managed with percutaneous nephrostomy and ureteral stent. We recommend the use of nonirradiated bowel segment for urinary diversion as transverse colon or jejunal conduit in patients who have received previous high doses of pelvic radiotherapy. For the management of urinary complications post pelvic exenteration, reoperation is required for most urinary fistula but ureteral obstructions can be managed with percutaneous nephrostomy and ureteral stent.

Volume expanded diuretic renography in the postnatal assessment of suspected uretero-pelvic junction obstruction.

Controversy surrounds the role of 99mTc-diethylenetriamine pentaacetic acid renography in suspected uretero-pelvic junction obstruction in early life. Accordingly, we retrospectively reviewed 18 patients (28 hydronephrotic kidneys) with a mean age of 2 mo (range: 1 wk-6 mo) who underwent a total of 36 scans using intravenous volume expansion (10 ml/kg) and furosemide diuresis (1 mg/kg). Initial scans were classified as obstructed, not obstructed or indeterminate using differential renal function, furosemide washout T 1/2 and visual assessment of tracer clearance. Those initially classified as obstructed (n = 8) have been surgically confirmed. In the indeterminate (n = 6) and nonobstructed (n = 14) groups, three and two kidneys, respectively, developed obstruction on progress scans. Mean follow-up in the nonsurgical patients was approximately 9 mo (range: 4-17 mo). A total of 13 kidneys had developed obstruction by renographic criteria, and to date 12 have surgical confirmation. Our data indicate that: (1) scans classified as obstructed correlate well with surgery; (2) an initial classification of indeterminate or nonobstructed does not exclude later development of obstruction; and (3) serial scans correctly stratify children with possible uretero-pelvic junction obstruction.

Antenatal diagnosis of pelvic hydronephrosis: assessment of renal function and drainage as a guide to management.

The optimal management of children with antenatally diagnosed unilateral hydronephrotic kidneys is unclear. We have monitored renal function and drainage using 99mTc-DTPA renography in 77 children with such kidneys presenting at 1-14 mo of age with the aims of throwing light on the natural history of the condition and evaluating the response of the kidney to pyeloplasty. Since management was independent of the drainage criteria on renography, the opportunity also was presented to evaluate the efficacy of diuretic renography for diagnosing obstruction in these children. Follow-up ranged between 1 and 6 yr, during which renography was performed between 2 and 6 times in each patient. Thirty-nine patients were treated conservatively, while 30 patients underwent pyeloplasty at varying times after presentation. No overall significant change in function was observed either in the nonoperated children or as a result of surgery. This also applied to sub-groups of children with poor drainage. Function improved significantly, however, in a sub-group of nonoperated children who presented with impaired function in the hydronephrotic kidney. Surgery, although having no overall effect on function, significantly improved drainage. As a means of identifying obstruction, 99mTc-DTPA diuretic renography was unreliable, erroneously indicating obstruction in 24 nonoperated children in whom function of the hydronephrotic kidney never became abnormal and who could not, therefore, have been considered to have obstruction. This retrospective study underlines the importance of performing a randomized prospective study on the value of pyeloplasty in this group of children.