Ureteral stricture: experience with 31 cases

Analysis of the Efficacy and Risk Factors for Failure of Balloon Dilation for Benign Ureteral Stricture

This study aimed to investigate the efficacy of balloon dilation in ureteral stricture and to analyze the risk factors for the failure of balloon dilation, which will hopefully provide some reference for clinicians to develop treatment plans. We retrospectively analyzed 196 patients who underwent balloon dilation between January 2012 and August 2022, 127 of whom had complete baseline and follow-up data. General clinical data, perioperative data, balloon parameters at the time of surgery, and follow-up results were collected from the patients. Univariate and multivariate logistic regression analyses were performed for the risk factors for surgical failure in patients undergoing balloon dilatation. The success rates of balloon dilatation (n = 30) and balloon dilatation combined with endoureterotomy (n = 37) for lower ureteral stricture at 3 months, 6 months, and 1 year were 81.08%, 78.38%, and 78.38% and 90%, 90%, and 86.67%, respectively. The success rates of balloon dilation at 3 months, 6 months, and 1 year in patients with recurrent upper ureteral stricture after pyeloplasty (n = 15) and primary treatment (n = 30) were 73.33%, 60%, and 53.33% and 80%, 80%, and 73.33%, respectively. The success rates of surgery at 3 months, 6 months, and 1 year for patients with recurrence of lower ureteral stricture after ureteral reimplantation or endoureterotomy (n = 4) and primary treatment with balloon dilatation (n = 34) were 75%, 75%, and 75% and 85.29%, 79.41%, and 79.41%, respectively. Multivariate analysis of the failure of balloon dilation showed that balloon circumference and multiple ureteral strictures were risk factors for balloon dilation failure (OR = 0.143, 95% CI: 0.023-0.895, p = 0.038; OR = 1.221, 95% CI: 1.002-1.491, p = 0.05). Balloon dilation combined with endoureterotomy in lower ureteral stricture had a higher success rate than balloon dilation alone. The success rate of balloon dilation in the primary treatment of the upper and lower ureter was higher than that of balloon dilation in the secondary treatment after failed repair surgery. Balloon circumference and multiple ureteral strictures are risk factors for balloon dilation failure.

Is there still a role of balloon dilatation of benign ureteric strictures in 2019?

Introduction and Objectives: Reconstructive surgery for benign ureteric strictures and long term nephrostomy are often invasive and lead to poor quality of life. Balloon dilatation has the potential to bridge this gap. We present the outcome of our series and examine the risk factors of stricture recurrence.Materials and Methods: There were 109 strictures in our series from August 2012 to July 2018 in our single center retrospective cohort analysis. All strictures were dilated retrogradely or antegradely and followed by stenting. Follow-up imaging was done to assess stricture recurrence.Results: Mean patient age was 57.7-years-old (SD ± 12.6). Mean follow-up was 20.2 months (SE ± 1.8). All strictures were successfully dilated and stented. Overall, mean patency rate was 63.7% at mean follow-up of 20.2 months (SE ± 1.8). Strictures caused by stone/inflammation had 28.0% (21/75) risk of recurrence compared to iatrogenic causes, 63.6% (7/11), and radiotherapy, 100.0% (5/5) (p = 0.001). Non-incidental strictures also had significantly higher risk of recurrence at 57.4% (27/47) vs. incidental strictures at 13.6% (6/44) (p = 0.000). The mean length of strictures was 12.5 mm (SE ± 1.7) in the recurrence group vs. 9.6 mm (SE ± 0.7) in those without recurrence (p = 0.001). The presence of ipsilateral atrophic kidney was associated with 72.2% (13/18) risk of recurrence vs. non-atrophic kidney 27.4% (20/73) (p = 0.000). The mean age of stricture was 14.5 months (SE ± 4.6) and 5.2 months (SE ± 2.1) in the recurrence and non-recurrence groups, respectively (p = 0.013).Conclusions: Balloon dilatation of benign ureteric stricture is a feasible option. Its effect can be long-lasting in selected patients, that is, non-irradiated, incidental, short strictures with normal kidneys. This will benefit patients unfit for reconstructive surgery.

Endoscopic Balloon Dilatation in the Treatment of Benign Ureteral Strictures: A Meta-Analysis and Systematic Review

BACKGROUND AND PURPOSE

Although balloon dilatation is one of the main endoscopic procedures used to treat benign ureteral strictures, its precise efficacy remains controversial. We aimed to identify, combine, and analyze existing published data to ascertain the efficacy of endoscopic balloon dilatation for benign ureteral strictures.

METHODS

In December 2018, a literature search was performed using Medline, Embase, and Web of Science databases. We included reports in which the study population consisted of patients who underwent endoscopic balloon dilatation for the treatment of benign ureteral strictures. Technical, short-term, and long-term success rates (expressed as mean ± standard error) were adopted as the outcome measures.

RESULTS

Using our search strategy, a total of 19 studies (all series reports) were included for analysis. Using a random-effects model, the pooled technical success rate of endoscopic balloon dilatation for benign ureteral strictures was found to be 89% ± 4%. Furthermore, the short-term success rate (i.e., 3 months after surgery) was 60% ± 10%, and the long-term success rate (i.e., 6-12 months after surgery) was 54% ± 14%. In the subgroup analysis, the success rate of endoscopic balloon dilatation for ≤2-cm benign ureteral strictures was significantly higher than that for >2-cm ones (odds ratio [OR]: 0.13; 95% confidence interval [CI]: 0.05-0.35). In addition, the success rate in cases with strictures of onset timing ≤3 months was relatively higher than that in cases with strictures of onset timing >3 months (OR: 0.46; 95% CI: 0.15-1.43).

CONCLUSION

Our study indicates that endoscopic balloon dilatation has a high success rate in the treatment of benign ureteral strictures with length ≤2 cm and onset timing ≤3 months. However, there is still no consensus on balloon type, dilatation pressure, expansion number, postoperative ureteral stent type, and stent retention time for the balloon dilatation technique.

Current status of minimally invasive endoscopic management of ureteric strictures

Endourological techniques are used more often nowadays in the treatment of ureteric strictures of various etiologies. Advances in technology have provided new tools to the armamentarium of the endoscopic urological surgeon. Numerous studies exist that investigate the efficiency and safety of each of the therapeutic modalities available. In this review, we attempt to demonstrate the available and contemporary evidence supporting each minimally invasive modality in the management of ureteric strictures.

Ureteroenteric anastomotic stricture: novel use of a cutting balloon dilator

INTRODUCTION

Management of ureteroenteric strictures presents a significant challenge because of its intraabdominal location and morbidity associated with open surgical management. The peripheral cutting balloon microsurgical dilatation device (PCBD), approved by The United States Food and Drug Administration (USFDA) for use in coronary angioplasty, features a 2-cm noncompliant balloon with four microsurgical blades mounted longitudinally on its outer surface. We evaluated the feasibility and outcome of this cutting balloon dilator in the treatment of ureteroenteric anastomotic strictures.

MATERIALS AND METHODS

Three patients with a 1-cm or less ureteroenteric stricture underwent a transluminal incision under fluoroscopic guidance. Percutaneous access was obtained and a guidewire was introduced into the renal pelvis and ureter in antegrade fashion and passed through the stricture. The exact length of the strictured segment was measured. The PCBD was deployed over the guidewire and the balloon was inflated at the stricture site. The maximum diameter of the inflated balloon was 8 mm. Approximately 30 seconds later, the balloon was deflated and the enlarged passage from the ureter to the ileal loop was verified under fluoroscopy. A ureteral stent was placed and removed at 6 weeks after the procedure.

RESULTS

Postoperative computed tomography scans at 12 months revealed improved hydronephrosis. All patients were asymptomatic postoperatively. One patient had a solitary kidney and creatinine level decreased significantly following the procedure.

CONCLUSION

Dilatation and incision with PCBD is a novel approach for the treatment of the short ureteroenteric anastomotic strictures. Long-term data need to be obtained to establish the efficacy of this technique.

Endoscopic Management of Ureterointestinal Strictures after Radical Cystectomy

PURPOSE

To summarize the status of endoscopic treatment for ureterointestinal anastomotic strictures after radical cystectomy.

MATERIALS AND METHODS

We reviewed the English-language literature identified by PubMed and MEDLINE to evaluate the efficacy of various treatment options for these strictures.

RESULTS

Cumulative success rates from multiple studies analyzing patency after balloon dilation, endoureterotomy, and metal stenting specifically for ureteroenteric strictures were 18%, 63%, and 83%, respectively. Studies have not clearly shown any significant advantage over any specific cutting modality. The use of metal stents appears promising but is still fraught with complications of tissue ingrowth and recurrent obstruction. Clinical factors that appear to be associated with a poor prognosis are age >60 years, left-sided strictures, length >1 cm, stenting <4 weeks, and poor function in the affecting kidney.

CONCLUSION

Ureteroenteric strictures remain the most challenging and difficult of all ureteral strictures to treat. An evolution of technology has helped advance the therapeutic options available. Given the rarity of this condition, limited study designs, and small numbers of patients, conclusive statements regarding the optimal treatment for this condition are difficult. Given its patency rates and possible complications, endoureterotomy should be considered the initial treatment of choice in properly selected patients.

Ureteroscopic endoureterotomy

OBJECTIVE

To highlight the current status of ureteroscopic endoureterotomy (UE) by reporting extensive experience with the endoscopic management of ureteric strictures, with special emphasis on factors determining success, and by reviewing publications on the minimally invasive management of ureteric strictures.

PATIENTS AND METHODS

The study comprised 50 patients (mean age 53 years, range 18-85, equal sex distribution) with ureteric strictures of varying causes; all had their stricture treated endoscopically. The follow-up was 0.5-9 years; 10 patients with recurrent strictures had two ipsilateral stents placed to try to improve the outcome, and eight patients with completely obliterating strictures were treated by ureteroscopic re-canalization.

RESULTS

The site of stricture had no bearing on the eventual outcome. Patients with uretero-enteric and malignant strictures did not fare so well. The most important predictor of failure was the length of the stricture, with failure in all seven patients with strictures of > 2 cm. In the 10 patients treated with two ipsilateral stents, eight were successful, which was very promising considering that these patients had recalcitrant strictures and placing one stent had previously failed. The overall success rate was 74%.

CONCLUSION

UE has become the procedure of choice for the initial management of ureteric strictures. Simple balloon dilatation is also effective in certain situations. The characteristics of the stricture often govern the eventual outcome. In properly selected cases success rates of approximately 75% can be expected.

Update On Minimally Invasive Management of Ureteral Strictures

PURPOSE

To review the role of minimally invasive management in ureteral stricture disease.

MATERIALS AND METHODS

A literature search was performed on the MEDLINE database through 2002 concerning endoscopic treatment of patients with ureteral strictures.

RESULTS

Many endourologic methods are available for ureteral strictures. Ureteral dilation may be accomplished in most cases, with various rates of success depending on stricture etiology, location, and length. Endoureterotomy also leads to long-term patency in properly selected cases and appears to be superior to dilation alone.

CONCLUSIONS

Significant advances in technique and technology have improved our ability to treat ureteral strictures without the need for open surgery in most patients.

Ureteral replacement using porcine small intestine submucosa in a porcine model

OBJECTIVES

To investigate an alternative technique using an onlay patch of porcine small intestine submucosa (SIS) allograft to bridge a ureteral defect. For ureteral strictures that fail endourologic management, few options are available for minimally invasive repair or reconstruction. Although laparoscopic interposition of a tubularized allograft of porcine SIS has great promise, animal studies have yielded mixed results.

METHODS

In 9 anesthetized female pigs, cystoscopy and retrograde pyelography were performed, and a ureteral stent was placed. Transperitoneal laparoscopic access was obtained, and a segment of ureter 2 cm long and encompassing one half the ureteral circumference was excised. An oval-shaped patch of SIS was sutured to the native ureter to cover the defect. In one control survival animal, the ureter was excised and a stent placed, but no SIS onlay was performed. Two pigs were killed immediately. In the survival group (6 pigs), the stents were removed at 1 week (n = 2), 2 weeks (n = 2), or 4 weeks (n = 2) and the corresponding animals were killed at 3 weeks (n = 2), 6 weeks (n = 2), and 9 weeks (n = 2). Intravenous urography was performed to evaluate renal function, and retrograde pyelography was performed after harvest to identify ureteral stricture or obstruction. The ureteral grafts were measured and examined histologically.

RESULTS

All 6 kidneys from the survival group were grossly normal, appeared promptly on intravenous urography, and were patent on retrograde pyelography. The control animal demonstrated complete ureteral obstruction. By 9 weeks, the SIS graft was replaced with ureteral tissue, including the muscle layers. The epithelium was primarily transitional epithelium, with focal intestinal metaplasia. The submucosa and ureteral musculature appeared histologically normal.

CONCLUSIONS

In the porcine model, a patch graft technique using SIS appears to induce ureteral regrowth. Renal function remained intact, and no evidence of stricture was demonstrated on radiographic imaging. Before clinical application of this technique, evaluation in a stricture model is required.

Endoscopic treatment of benign ureteral strictures

BACKGROUND

The traditional choice of procedure for treatment of ureteral stricture is open surgical repair. Advances in endourology have provided the urological surgeon with an alternative to open surgery for the treatment of benign ureteral stricture.

METHODS

Twenty-seven benign ureteral strictures in 24 patients were treated by the endourological method. Twelve endoureterotomies were performed using a cold knife via a 9.5Fr Storz ureteroscope and 15 high pressure balloon dilations were performed. The ureters were stented with 7 Fr double-J stents for 6 weeks.

RESULTS

The success rate was 9/12 (75%) in the endoureterotomy group and 9/15 (60%) in the balloon dilation group after follow-up for more than 6 months.

CONCLUSIONS

Endoscopic treatment of ureteral strictures appeared to be a safe and reasonably effective modality for the treatment of ureteral strictures, especially for the short type that are non-ischaemic in origin and not associated with radiation therapy. Endourological treatment of ureteral strictures is the procedure of choice for initial management of benign ureteral strictures and has high success rates and fewer complications.

Balloon catheter dilatation in the treatment of ureteral and ureteroenteric stricture

Balloon catheter dilatation is a low-cost alternative to open surgery in patients with ureteral strictures, leading to low morbidity and short hospitalization. The goal of this study was to evaluate the results of this technique in patients with inflammatory ureteral strictures or ureteroenteric strictures after radical cystectomy. Twenty-five ureteral strictures in 20 (15 male, 5 female) patients were consecutively treated by high-pressure balloon dilatation: 14 cases of ureteroenteric stricture (9 after ileal cutaneous diversion, and 5 after orthotopic enterocystoplasty) and 11 of ureteral stricture from various inflammatory causes (tuberculosis, iatrogenic injury, radiation therapy, parasitosis). Dilatation was performed by an antegrade (ureteroenteric strictures) or retrograde (inflammatory strictures) approach using a balloon insufflated up to 10 to 20 atm for 5 to 15 minutes. The ureter was stented for a mean time of 2.1 months (range 1-5 months). Results were evaluated clinically and radiologically (intravenous urogram or CT scan). Immediate success was assessed by intraoperative radiologic monitoring. Long-term success was defined as the absence of recurrence of the stenosis after 6 months. Nineteen procedures were successful among the 23 evaluable cases. With a mean follow-up of 16 months (range 6-39 months), the long-term success rate was 52%: 40% in ureteral strictures and 61% in ureteroenteric strictures. Five strictures secondary to cutaneous diversion and six caused by radiation therapy recurred after dilatation. After cutaneous diversion, the failure occurred mostly at the anastomosis and involved the crossed-over ureter. This study shows that high-pressure balloon dilatation of ureteral strictures has a high early success rate and a long-term success rate of 52%. It can therefore be considered as an alternative to open surgery.

Holmium:YAG laser endoureterotomy for treatment of ureteral stricture

OBJECTIVES

Endourologic techniques ranging from balloon dilation to endoincision with electrocautery, cold knife, and lasers have been increasingly used in recent years for the treatment of ureteral strictures. While the long-term results may not be as reliable or as durable as traditional reconstructive surgical techniques, they can be accomplished with much less morbidity. Recently, the holmium:yttrium-aluminum-garnet (YAG) laser, which possesses both cutting and coagulating properties, has been demonstrated to have many applications in urology. We report our experience with this laser in the endoscopic treatment of ureteral strictures.

METHODS

We reviewed the charts and follow-up history of 22 patients in whom the holmium:YAG laser was used to treat ureteral strictures from a variety of causes and including those in ureteroenteric anastomoses. Strictures were either approached in a retrograde fashion with a 6.9F ureteroscope or antegrade with flexible instruments in the cases involving ureteroenteric strictures. The only energy source employed was the laser, followed by balloon dilation. Indwelling stents were left in place for at least 4 weeks postoperatively and follow-up was obtained with radiographic imaging.

RESULTS

A minimum 9-month follow-up was available for 18 patients. There were 5 patients who had developed recurrent strictures and were therefore considered treatment failures. Each of these patients failed in less than 3 months and all had either lengthy or complex strictures noted at the time of surgery. One patient was lost to follow-up and three recent patients have follow-up of 3 to 6 months showing no evidence of recurrent stricture formation. Overall, 16 of 21 (76%) patients are clinically well with no evidence of stricture recurrence.

CONCLUSIONS

Endoureterotomy for ureteral stricture disease is a minimally invasive, less morbid, but ultimately less successful, alternative to open surgical reconstruction. Stricture length and etiology remain the most important determinants of success. The holmium:YAG laser, with its ability to precisely cut tissue and provide hemostasis and its multiuse potential and compatibility with small rigid and flexible endoscopic instruments, is an ideal tool for performing endoureterotomy.

Techniques for stenting the normal and obstructed ureter

Ureteral obstruction is a common cause of urologic morbidity requiring quick and effective treatment, as prolonged obstruction can cause pain, infection, and eventual loss of renal function. Few would argue that initial drainage or bypassing of the obstruction is favorable initial management; however, urologists are often-times faced with technically difficult cases not responsive to the standard operative maneuvers. Recognizing the diversity of pathology and the potentially complicating issues, urologists should have in their armamentarium a systematic approach or algorithm for dealing with these common dilemmas, as well as an understanding of various tricks of the trade. This knowledge will prevent heightened anxiety at the time of surgery and will ensure the availability of the proper operative equipment. This article outlines an approach and discusses the obstacles and options in stenting the obstructed ureter.

Long-term results of endoureterotomy for benign ureteral and ureteroenteric strictures

PURPOSE

We reviewed the results of endoureterotomy for benign ureteral and ureteroenteric strictures to determine efficacy and factors associated with a successful outcome.

MATERIALS AND METHODS

Followup was available for 69 patients undergoing 77 endoureterotomies. Success was defined as symptomatic improvement and radiographic resolution of obstruction. Kaplan-Meier survival curves were constructed and data were analyzed with a Cox proportional hazards model.

RESULTS

None of 9 procedures in patients with the ipsilateral kidney contributing less than 25% of total renal function was successful. Among the 38 remaining benign ureteral stricture treatments with ipsilateral function 25% or greater with a median followup of 28.4 months among successful cases the 3-year success rate was 80%. No procedure failed beyond 11 months and there were 25 patients at risk beyond this point. Among the 30 remaining ureteroenteric stricture treatments with ipsilateral function 25% or greater the success rates at 1, 2 and 3 years were 73, 51 and 32%, respectively. Failures were noted during the first 36 months but none occurred later and 5 patients were at risk beyond this point. Overall, complete or tight strictures were less successfully treated. A nonischemic etiology, a stent 12F or greater and injection of triamcinolone into the bed of the incised stricture were associated with better outcome for strictures longer than 1 cm.

CONCLUSIONS

Endoureterotomy of benign ureteral strictures is associated with an excellent outcome (80% success at 3 years). Endoscopic treatment of ureteroenteric strictures is less successful but still offers a reasonable first step (32% 3-year success rate). For all strictures failure is likely if ipsilateral renal function is poor. For strictures longer than 1 cm. use of a stent 12F or greater and injection of triamcinolone appear to be beneficial.

Iatrogenic ureteral injuries: a 20-year experience in treating 165 injuries

PURPOSE

We reviewed the causes, treatment and morbidity associated with iatrogenic ureteral injuries.

MATERIALS AND METHODS

From 1972 to 1992 the charts of all patients with the diagnosis of iatrogenic ureteral injury were reviewed and 156 injuries were identified.

RESULTS

Urological, gynecological and general surgical procedures accounted for 70 (42%), 56 (34%) and 39 (24%) injuries, respectively. Of the injuries 91% occurred in the lower third, 7% in the middle third and 2% in the upper third of the ureter, respectively. Among the urological lesions 77% were identified at injury compared to only 33% of the nonurological cases. Nonurological and urological ureteral injuries detected postoperatively required 1.8 and 1.6 procedures, respectively, compared to only 1.2 procedures in both groups (p < 0.0006 and p < 0.013) when the injuries were detected immediately at operation.

CONCLUSIONS

Endourological procedures are the most common cause of iatrogenic ureteral injuries. When identified at injury and treated properly such injuries seldom lead to loss of renal function.

Endoscopic management of total ureteral occlusion and ureterovaginal fistula

Between August 1991 and June 1994, endoureterotomy was performed in nine patients for total ureteral occlusion. Four of these patients had an associated ureterovaginal fistula. The total ureteral occlusions were iatrogenic in eight patients and the result of trauma in one. The prone split leg position was used to facilitate simultaneous antegrade and retrograde ureteroscopy in all nine patients. The "cut-to-the-light" technique was utilized in six patients and a new technique employing a fascial incising needle was used in five patients. Five patients developed ureteral strictures within 5 months of the primary procedure that were corrected endoscopically. With a mean follow-up of 22 months, all nine patients have a successful outcome. Endoscopic management of difficult urteral disease such as total urteral occlusion and ureterovaginal fistula is a useful alternative to open surgery.

Efficacy of a new endoureterotomy balloon for the treatment of benign ureteral strictures using the porcine model

OBJECTIVES

Endoureterotomy and balloon dilation are techniques that have shown promise as treatment modalities for benign ureteral stricture disease. In this animal investigation, the results of a new endoureterotomy balloon that simultaneously incises and dilates the ureteral stricture via a retrograde approach are discussed.

METHODS

Using the female pig model, 9 subjects with benign ureteral strictures were treated: 7 with the endoureterotomy balloon and 2 with balloon dilation only.

RESULTS

Success based on radiologic parameters and Whitaker testing was obtained in 5 of the 7 animals treated by endoureterotomy. In both animals treated by balloon dilation only, recurrent ureteral stricture disease developed.

CONCLUSIONS

This preliminary investigation suggests that this new device may be an effective treatment for benign ureteral stricture disease and that the further study in clinical trials is warranted.

Endo-ureteroplasty with a free urothelial graft

Endo-urological therapy for ureteral strictures is usually limited to lesions 1 cm. or shorter. In an attempt to develop an endo-urological approach to treat longer ureteral strictures, we studied the clinical use of a transurethrally harvested free graft of bladder urothelium placed into the incised stricture bed. A total of 6 patients with ureteral strictures 1.5 to 8 cm. long (average 2.9 cm.) underwent endo-surgical management via free urothelial graft endo-ureteroplasty. Operative time averaged 5.5 hours. Complications included urinoma in 1 patient, hyponatremia in 1 and a postoperative renal pseudoaneurysm in 1. Four patients had long-term (that is 22 months or longer) successful results. Free urothelial graft endo-ureteroplasty, while tedious, may be a useful endo-surgical technique for treatment of long ureteral strictures.

Fluoroscopically guided incision of ureteral strictures in pigs with the cautery-wire balloon catheter: a phase 1 study

We investigated a catheter that can longitudinally incise ureteral strictures under fluoroscopic guidance without the need for ureteroscopy and its attendant risks. The catheter consists of a low-pressure balloon and an overlying cautery wire; the balloon allows precise localization of the stricture, seen as a waist in the balloon, and the overlying cautery wire can be fluoroscopically oriented at the stricture. One to two centimeter ureteral strictures were created in 6 swine. Two to four weeks later strictures were incised in a retrograde or antegrade fashion with the cautery-wire balloon catheter, and double J stents placed for a duration of three weeks. In 5 of 6 renal units strictures improved anatomically with resolution of hydronephrosis at 3 to 4 months' follow-up. Urodynamic absence of obstruction was verified by Whitaker testing. In one animal, the tip of the catheter dislodged in the ureter with subsequent loss of the renal unit. The engineering error that lead to this complication has since been rectified. With correction of the aforementioned problem, this Phase 1 study has demonstrated the feasibility, safety and preliminary efficacy of the cautery-wire balloon catheter for endourologic management of ureteral strictures.

Balloon dilatation of ureteral strictures

Balloon catheter dilatation is now an accepted method for treating strictures of the upper urinary tract. A successful result was obtained in 34 (85%) of 40 patients with symptomatic stricture. The number of dilatations required for improved runoff from the kidney was one in 26 cases, two in six cases and three in one case. One patient had a permanent stent and six required a conventional operation. There were seven recurrences of stricture, all within 4 months after the dilatation. One of these patients required nephrectomy because of nonfunctioning kidney.

Endoureterotomy for treatment of ureteral strictures

Advances in endosurgical technology have provided the urological surgeon with an alternative to open surgery for the treatment of ureteral strictures. We report the use of an endoscopic intraureteral incision (endoureterotomy) followed by balloon calibration to treat benign ureteral strictures in 13 patients. With an average subjective and objective followup among successful endoureterotomies of 20 months (all cases 12 months or greater), the overall success rate for this procedure is 62%. Of these patients 5 also received triamcinolone injections into the stricture bed following incision and dilation. This method appeared to influence favorably subsequent ureteral patency. The only operative complication was a urinoma, which resolved without intervention. Endoureterotomy appears to be a safe and reasonably effective modality for the treatment of ureteral stricture disease.

The cold-knife technique for endourological management of stenoses in the upper urinary tract

Between 1985 and October 1989 we managed 13 patients with primary and 43 with secondary obstruction of the upper urinary tract with the endourological cold-knife technique. We treated 26 patients with stenosis of the ureteropelvic junction, 9 with infundibular stenosis, 12 with ureteral obstruction after inflammation or radiation therapy, 7 with stricture of the ureter in kidney transplants and 2 with stenosis of the ureter after ureterosigmoidostomy. Endourological management was successful in 42 of 56 cases with a decrease or total elimination of obstruction. Stenosis recurred in 9 patients. Our results indicate that the cold-knife technique should be attempted as the initial approach in all cases of primary or secondary obstruction of the upper urinary tract.

Interventional procedures in the upper urinary tract

The introduction and acceptance of percutaneous nephrostomy as a safe and effective alternative to surgical nephrostomy served as the impetus for the development and expansion of an ever-increasing number of techniques that are encompassed by the term "interventional uroradiology." This article reviews many of the nonvascular interventional techniques that have proliferated during the past decade and that are currently used in the kidney, ureter, and perinephric space. The authors emphasize those procedures that are most frequently employed, as well as their own preferences and perspectives on these procedures.

Ureteral obstruction and ureteral fistulas after aortofemoral or aortoiliac bypass surgery

Ureteral injury after aortofemoral or aortoiliac bypass surgery has seldom been described in the literature considering the large number of bypass operations performed. Some causative factors, such as the position of the bypass, are obvious while others are less clear. However, no attempt has been made to unify criteria to establish a management protocol. Of 154 cases of ureteral units with ectasia reviewed ureteral fistulas were present in 19. Radiological ureteral obstruction appears to precede fistula formation. Symptoms, time of diagnosis and treatment according to the predominant etiology have been discussed. Etiological (in varying degrees of importance), clinical and diagnostic criteria, together with a management and therapeutic protocol in which early and late lesions are clearly differentiated were established, while bearing in mind that not all radiological obstruction patterns correspond to true ureteral lesions.

Endourological management of ureteral strictures

We reviewed the records of 20 patients (21 ureters) treated during the last 5 years for ureteral stricture disease. The causes of stricture formation included ureterolithotripsy in 47.7% of the patients, open ureterolithotomy in 9.5%, other urological procedures in 23.8%, general surgical and gynecological procedures in 9.5% and miscellaneous factors in 9.5%. A total of 20 patients (21 ureters) underwent endourological treatment with balloon dilation (19) or balloon dilation and internal ureterotomy (2), with good results in 57.1% and a mean followup of 24 months. Of the 9 patients who failed endourological management 3 underwent successful open repair, 3 underwent nephrectomy, and 3 had a relatively large ureteral lumen and became asymptomatic, receiving no further treatment. The interval between injury and treatment was not a decisive factor. The length of ureteral stricture assumes the most significant parameter to predict success in the treatment of ureteral stricture. There were no intraoperative or postoperative complications. The association of balloon dilation and incision by special endoureterotomy scissors is a potentially useful technique.