Percutaneous balloon dilatation for the treatment of early and late ureteral strictures after renal transplantation: long-term follow-up

Robotic-assisted Laparoscopic Repair of Kidney Transplant Ureteral Strictures

OBJECTIVE

To evaluate outcomes of robotic-assisted transplant ureteral repair (RATUR) for the management of kidney transplant ureteral strictures (TUS).

METHODS

We retrospectively analyzed 41 consecutive patients who underwent RATUR for TUS at multiple tertiary referral centers between January 2016 and December 2022. RATUR was performed utilizing a robotic-assisted transperitoneal approach. The primary outcome was stricture recurrence rate and secondary outcomes included postoperative complicate rate, determining factors impacting with allograft functional recovery, and rate of conversion to open surgery. Categorical and continuous variables are displayed as total number (Percentage) or median [Interquartile Range], respectively. Pearson correlation coefficient was utilized to assess categorical variable correlation with creatinine.

RESULTS

The median age was 56years [44,66]. The female-to-male ratio was 1.1:1. Approximately 66% of patients were dialysis-dependent prior to kidney transplantation. TUS was identified at a median time of 4months [2, 15.5] following kidney transplant. Median stricture length was 2 cm [1.22, 2.9 cm]. There were no TUS recurrences with a median follow-up of 36months [24,48]. There were 3 Clavien grade 2 and 1 Clavien grade 3 complications (9.5%). No baseline characteristics or preoperative diagnostics were correlated with a long-term decline in renal allograft function.

CONCLUSION

RATUR has excellent and durable outcomes with low complication rates. These findings encourage the use of a minimally invasive definitive repair as a first-line treatment option for the management of TUS.

Transplant Renal Interventions

Renal transplantation is the most commonly performed solid-organ allograft surgery; in 2021, 25487 kidneys were transplanted in the United States, and nearly 42,000 adult patients were listed for transplant. As the treatment of choice for patients with end-stage renal disease, transplantation is performed at more than 250 centers. Despite a high rate of success, renal transplantation is not without complication, and the interventional radiologist plays a crucial role in the management of the postoperative patient. Knowledge of postsurgical anatomy, imaging findings, and technical challenges unique to these patients is important for the safe and effective treatment of transplant-related conditions. We offer a guide to the most common interventions in the renal transplant population, including biopsy, vascular interventions, and the management of urinary obstruction.

Robotic ureter reconstruction using the native ureter to treat long-segment ureteral stricture of the transplant kidney utilizing Indocyanine green: The first Korean experience

PURPOSE

Ureteral strictures are a common complication after kidney transplantation. Open reconstruction is preferred for long-segment ureteral strictures that cannot be resolved endoscopically; however, it is known to have the potential to fail. We report 2 successful cases of robotic reconstruction surgery of a transplant ureter using the native ureter with the aid of intraoperative Indocyanine green (ICG).

MATERIALS AND METHODS

Patients were placed in semi-lateral position. Using Da Vinci Xi, the transplant ureter was dissected, and the stricture site was identified. End-to-side anastomosis of the native ureter to the transplant ureter was performed. ICG was utilized to identify the course of the transplant ureter and confirm the vascularity of the native ureter.

RESULTS

Case 1: A 55-year-old female underwent renal transplantation at another hospital. She had recurrent febrile urinary tract infections (UTIs) and a ureteral stricture requiring percutaneous nephrostomy (PCN). The PCN and ureteral stent were removed successfully after surgery. The patient had only 1 febrile UTI episode after surgery. Case 2: A 56-year-old female underwent renal transplantation at another hospital. She had acute pyelonephritis 1-month post-transplantation, and a long-segment ureteral stricture was identified. She developed a UTI with anastomosis site leakage in the early postoperative period, which resolved with conservative treatment. The PCN and ureteral stent were removed 6 weeks after surgery.

CONCLUSIONS

Robotic surgery for managing long-segment ureteral stricture after kidney transplantation is safe and feasible. The use of ICG during surgery to identify the ureter course and its viability can improve the success.

Ureteral stricture after pediatric kidney transplantation: Is there a role for percutaneous antegrade ureteroplasty?

INTRODUCTION

Ureteral obstruction following pediatric kidney transplantation occurs in 5-8% of cases. We describe our experience with percutaneous antegrade ureteroplasty for the treatment of ureteral stricture in pediatric kidney transplant patients.

METHODS

We retrospectively reviewed all pediatric kidney transplantation patients who presented with ureteral stricture and underwent percutaneous antegrade ureteroplasty at our institution from July 2009 to July 2021. Variables included patient demographics, timing of presentation, location and extent of stricture, ureteroplasty technique and clinical outcomes. Our primary outcome was persistent obstruction of the kidney transplant.

RESULTS

Twelve patients met inclusion criteria (4.2% of all transplants). Median age at time of ureteroplasty was 11.5 years (range: 3-17.5 years). Median time from kidney transplantation to ureteroplasty was 3 months. Patency was maintained in 50% of patients. Seven patients (58.3%) required additional surgery. Four patients developed vesicoureteral reflux. Patients with persistent obstruction had a longer time from transplant to ureteroplasty compared to those who achieved patency (19.3 vs 1.3 months, p = 0.0163). Of those treated within 6 months after transplantation, two patients (25%) required surgery for persistent obstruction (p = 0.06). All patients treated >1 year after transplantation had persistent obstruction following ureteroplasty (p = 0.06).

CONCLUSION

Percutaneous antegrade ureteroplasty can be considered a viable minimally invasive treatment option for pediatric patients who develop early ureteral obstruction (<6 months) following kidney transplantation. In patients who are successfully treated with ureteroplasty, 67% can develop vesicoureteral reflux into the transplant kidney. Patients who fail early percutaneous ureteroplasty or develop obstruction >1 year after transplantation are best managed with surgical intervention.

Temporary Covered Metallic Ureteral Stent Placement for Ureteral Strictures following Kidney Transplantation: Experience in 8 Patients

This brief report presents 8 patients with silicone-covered metallic stent placement for ureteral strictures refractory to double-J stent placement, following kidney transplantation. Stent removal was successfully performed in 7 patients via antegrade (n = 4) or retrograde (n = 3) access 6 weeks to 6 months after stenting for elective removal (6-month interval, n = 3), urothelial hyperplasia (n = 2), or stent migration (n = 2), and their mean primary ureteral patency after stent removal was 15.4 months (range, 2-27 months). Hematuria (n = 2) and pain (n = 3) occurred, but resolved within 1 week. One stent was removed during reconstructive surgery. During follow-up of mean 22.6 months after stent removal, ureteral strictures recurred in 2 patients.

Robotic Surgery for the Reconstruction of Transplant Ureteral Strictures

OBJECTIVE

To demonstrate the feasibility and success of a robotic approach to reconstruction of ureterovesical anastomotic strictures in kidney transplants.

MATERIALS AND METHODS

Between November 2017 and December 2019, a total of 5 patients with transplant ureteral stricture were identified and treated with robot assisted laparoscopic repair. All patients were confirmed to have ureteral stricture with a preoperative antegrade nephrostogram through their nephrostomy tube and cystogram. The patients demographics, ureteral characteristics, type of procedure, and outcomes are reported.

RESULTS

All patients were diagnosed after evaluation for renal deterioration. The average age of the patients was 49 years old. The average stricture length was 2.5 cm, and the location was variable, though more commonly in the distal ureter. Three patients required a pyelo-vesicostomy, while 2 required a ureteroneocystostomy. The mean length of stay was 2.2 days. Average follow-up was 97 days, with all 5 patients having successful outcomes, no strictures or delayed leaks were identified. There were no wound infections or readmissions within 30 days.

CONCLUSION

Though a complex repair, the robot-assisted approach to transplant ureter reconstruction using either an end to side neoureterocystotomy or direct pyelo-vesicotomy is technically feasible and successful. Given the many advantages inherent in comparison to an open approach, the robotic repair offers significant advantages to both the patient and the surgeon who is experienced with robotic surgery and reconstructive principles.

Tubular vesicopyelostomy for the management of types 2 and 3 (long-segment) ureteric stenosis after kidney transplantation

Late ureteral stenosis following kidney transplantation needs immediate correction in order to protect allograft function and requires a complicated surgical procedure. In this study, we present the long-term results of tubular bladder reconfiguration and cystopyelostomy (tubular vesicopyelostomy), an innovative and practical procedure for the management of long-segment ureteric stenosis (types 2 and 3) after transplantation. Between 2002 and 2017, 722 kidney transplant patients were monitored at the University of Medical Sciences, Bozyaka Organ Transplantation and Research Center. Twenty-eight of these patients underwent tubular vesicopyelostomy operation; 17 male and 11 female patients with a mean age of 45.6 ± 10.5 years. Time to surgical intervention for urinary tract obstruction was 122.5 ± 114.7 months. The mean serum creatinine values previous to and 3 days following the tubular vesicopyelostomy operation were 3.46 ± 1.5 mg/dL and 1.75 ± 0.7 mg/dL, respectively (p < 0.0001). Within a mean follow-up period of 55.1 ± 40.9 months, functional grafts were recorded in 22 patients with a mean serum creatinine value of 1.92 ± 0.8 mg/dL. Only one patient developed anastomotic stenosis after the tubular vesicopyelostomy procedure, giving an overall success rate for tubular vesicopyelostomy of 96.4%. Six patients returned to hemodialysis. In five, the underlying etiology was not related to recurrent obstruction or surgical complications. Sixteen patients underwent allograft biopsy after the operation, but features of tubulointerstitial nephritis were seen in only one. Tubular vesicopyelostomy operation is a safe and successful method for the surgical treatment of late and complicated ureteral obstructions with excellent long-term results. It may be a good, practical alternative to other more sophisticated surgical options.

Self-Expandable Covered Metallic Stent (UVENTA) to Treat a Ureteral Stricture After Renal Transplant: A Case Report

We present the use of a self-expandable covered metallic stent (UVENTA; TaeWoong Medical, Gyeonggi-do, South Korea) to treat a ureteral stricture after kidney transplant. In this report, we describe the procedure and short-term outcomes of a patient with a recurrent distal stricture who did not respond to percutaneous balloon dilation. We decided to place this temporary stent as an alternative to complex surgery. The aim of the procedure was to get a chronic dilation of the stricture up to 7 mm to stabilize the fibrotic tissue. The procedure was easily and quickly performed by an antegrade and retrograde combined approach. The postoperative course was uneventful. The stent was left in situ for 7 months. No complications were noted, and the renal function remained stable. The stent was easily removed, and 5 months later there were no signs of recurrence. The UVENTA device was shown to be an easy, safe, and effective minimally invasive treatment for ureteral stricture in renal transplant. Proper permanence time and long-term results need to be explored.

Impact of ureteral stricture and treatment choice on long-term graft survival in kidney transplantation

We aimed to evaluate the influence of urological complications occurring within the first year after kidney transplantation on long-term patient and graft outcomes, and sought to examine the impact of the management approach of ureteral strictures on long-term graft function. We collected data on urological complications occurring within the first year posttransplant. Graft survivals, patient survival, and rejection rates were compared between recipients with and without urological complications. Male gender of the recipient, delayed graft function, and donor age were found to be significant risk factors for urological complications after kidney transplantation (P < .05). Death censored graft survival analysis showed that only ureteral strictures had a negative impact on long-term graft survival (P = .0009) compared to other complications. Death censored graft survival was significantly shorter in kidney recipients managed initially with minimally invasive approach when compared to the recipients with no stricture (P = .001). However, graft survival was not statistically different in patients managed initially with open surgery (P = .47). Ureteral strictures following kidney transplantation appear to be strongly negatively correlated with long-term graft survival. Our analysis suggests that kidney recipients with ureteral stricture should be managed initially with open surgery, with better long-term graft survival.

Robotic Autotransplantation and Management of Post-transplant Anastomotic Strictures: the Future Is Here

PURPOSE OF REVIEW

We set out to review the current published experience with robotic autotransplantation. Although the experience to date is limited, this surgery appears to be safe and technically feasible. We also examined the use of the robotic surgical platform for the management of post-transplant uretero-vesical anastomotic strictures.

RECENT FINDINGS

To date, only four reported cases of robotic autotransplantation have been described with two being performed completely intra-corporeally. An intra-corporeal approach is feasible for benign conditions, while malignant masses should be inspected and dissected extra-corporeally. Ureteric strictures after renal transplantation are common. To date, the experience with robotic surgical management is limited but has also been shown to be safe and feasible. While robotic autotransplantation is still in its infancy, it is feasible and appears to be safe. Renal allograft function and surgical outcomes are favorable and provide patients the option to have a historically more morbid surgery performed with a minimally invasive approach.

Ureteral Stenosis After Renal Transplantation-A Single-Center 10-Year Experience

BACKGROUND

Kidney transplantation (KT) is the definitive treatment for ESRD. Ureteral stenosis (US) is one of the most common urologic complications and has been reported in 2.6%-15% of KTs.

METHODS

We reviewed data for 973 consecutive KT procedures performed at our center from January 2004 to September 2014, with evaluation of US management and recurrence rate.

RESULTS

The 973 KTs were performed with the use of the direct ureterovesical (UV) implantation Paquin technique, and the mean follow-up time was 44.3 ± 30.2 [range, 3-111] months. During this period, 33 cases of US (3.39%) were reported. The interval from KT to US diagnosis was 10.6 ± 23.0 (range, 0.5-98.0) months. The majority of the US cases were located in the distal ureter and UV junction (83.9%), with only 2 cases of middle ureter stenosis and 2 cases of ureteropelvic junction. Mean US length was 2.5 ± 1.9 (range, 1.0-10.0) cm. Surgical management and global and treatment-specific recurrence rates were reviewed. Primary surgical treatment recurrence rate was higher for the endoscopic approach, with a mean global time from treatment to US recurrence of 6.9 ± 16.3 (range, 0-65) months and a median of 2.0 months. Open surgical approach was the main recurrence treatment option (74%). There were 2 cases of graft loss. Success rate evaluation of overall and treatment-specific primary surgical management did not reveal significant differences (P > .05) according to stenosis length (<1.5, 1.5-3.0, or >3.0 cm), time between transplant and stenosis (≤3, 3-12, or >12 mo), or stenosis location (distal, middle, or upper ureter). However, there was clearly a trend to higher success rate in smaller stenosis (<1.5 cm) and early management (≤3 mo), particularly with the use of balloon dilation.

CONCLUSIONS

US management should be decided on a case-by-case basis according to clinical characteristics, treatment-specific recurrence rate, and previous surgical options.

Preperitoneal Surgical Approach to Treat Vesicoureteral Anastomotic Leakage, Distal Stenosis or Reflux After Kidney Transplantation

BACKGROUND

If endourological approaches are not applicable to treat vesicoureteral anastomotic complications after kidney transplantation, the surgical gold standard in many transplant centers is pyeloureterostomy or ureteroureterostomy using the native ureter. We report an original preperitoneal technique that can be used for vesicoureteral reanastomosis in kidney transplant recipients not eligible for endourological treatment.

METHODS

Between January 2011 and December 2015, 18 kidney transplant recipients underwent this new surgical procedure. Of this number, 15 subjects with at least 1 year of follow-up were included in the analysis. The indications were vesicoureteral reflux, anastomotic stenosis, and leakage in 8, 5, and 2 patients, respectively. Briefly, a double J stent was preoperatively inserted into the grafted ureter. Surgery was performed through a Pfannenstiel incision. The preperitoneal space surrounding the bladder was dissected and the distal part of the grafted ureter was identified and mobilized. The anastomotic area was resected and another vesicoureteral anastomosis was performed (Lich-Gregoir technique), keeping the JJ stent in place for three weeks.

RESULTS

This procedure was performed 213 days (range 17-2608) after kidney transplantation. Median surgical duration was 179 minutes (range 112-314) and median hospital stay 8 days (range 4-14). The success rate was 86.7% (13/15), with a median follow-up of 1148 days (range 517-1808). In two patients, symptomatic recurrence of vesicoureteral reflux required a pyeloureterostomy using the native ureter.

CONCLUSIONS

The authors describe a simple technique that avoids transperitoneal dissection, potentially yielding more esthetic results thanks to easy access, as well as excellent outcomes.

Transplant Kidney Retrograde Ureteral Stent Placement and Exchange: Overcoming the Challenge

OBJECTIVE

To present a reliable technique for fluoroscopic controlled, large-bore, ureteral stent placement and exchange in transplant kidneys with persistent ureterovesical strictures.

MATERIALS AND METHODS

We reviewed the medical charts of all patients who underwent kidney transplant with persistent ureterovesical strictures who underwent ureteral stent placement or exchange at our institution between 2005 and 2015 using the new technique. Clinical characteristics and treatment outcomes of the study cohort were analyzed.

RESULTS

Ureteral stent insertion or stent exchange, using this technique, was performed in 32 renal transplant units. Median operating time was 24 minutes (interquartile range, 21-36.75 minutes). The overall success rate of the technique at first attempt was 96.9%. In 1 patient, drainage of the transplanted kidney with a nephrostomy tube was indicated after procedure failure. No other local or systemic complications were encountered, and no stent encrustation was noted in this cohort of patients. Renal function remained stable in all patients during a median follow-up of 59 months (interquartile range, 28-61 months).

CONCLUSION

Herein, we present in detail a step-by-step technique for the insertion and exchange of large-bore ureteral stents in transplanted kidneys. The technique was shown to be safe, effective, and highly successful.

Minimally invasive salvage therapy for transplanted renal allografts

PURPOSE

To evaluate the effectiveness of interventional therapy for complications of transplanted renal allografts.

MATERIALS AND METHODS

Between January 2009 and March 2014, 14 patients underwent interventional therapy for complications of renal allografts. Complications included transplant renal artery stenosis (TRAS), TRAS combined with pseudoaneurysms, transplant renal venous kinking and ureteral obstruction (UO). Serum creatinine (S.Cr) levels were evaluated before and after procedure. The characteristics and procedure outcomes of these patients with vascular and nonvascular complications were also analyzed.

RESULTS

All primary procedures were successfully performed, which included percutaneous transluminal angioplasty (PTA) for TRAS (n = 4), stenting and coil embolization for TRAS combined with pseudoaneurysms (n = 1), stenting for renal vein kinking (n = 2), and percutaneous nephrostomy (PCN) for UO (n = 7) and secondary antegrade stent placement in six UO patients after 1 week of PCN. No major procedure related complications occurred. S.Cr level subsequently improved from 6.0 ± 3.6 to 2.6 ± 2.1 mg/dL (p < 0.001), as well as patients' clinical features within 1 week after procedure. In our study, the onset time of vascular complications was earlier (<6 months) than nonvascular complications with significant difference (p < 0.001). During follow-up, the patient with TRAS and pseudoaneurysms suffered acute rejection 1 month after treatment and received transplant renal artery embolization. One patient with TRAS showed restenosis 4 months after procedure, and was retreated successfully with stenting. Thirteen cases reserved their transplanted renal allografts.

CONCLUSION

Interventional therapy could be prior considered for transplanted renal allograft complications as its effectiveness and minimal invasiveness in saving the transplanted renal grafts.

Diagnosis and management of ureteral complications following renal transplantation

When compared with maintenance dialysis, renal transplantation affords patients with end-stage renal disease better long-term survival and a better quality of life. Approximately 9% of patients will develop a major urologic complication following kidney transplantation. Ureteral complications are most common and include obstruction (intrinsic and extrinsic), urine leak and vesicoureteral reflux. Ureterovesical anastomotic strictures result from technical error or ureteral ischemia. Balloon dilation or endoureterotomy may be considered for short, low-grade strictures, but open reconstruction is associated with higher success rates. Urine leak usually occurs in the early postoperative period. Nearly 60% of patients can be successfully managed with a pelvic drain and urinary decompression (nephrostomy tube, ureteral stent, and indwelling bladder catheter). Proximal, large-volume, or leaks that persist despite urinary diversion, require open repair. Vesicoureteral reflux is common following transplantation. Patients with recurrent pyelonephritis despite antimicrobial prophylaxis require surgical treatment. Deflux injection may be considered in recipients with low-grade disease. Grade IV and V reflux are best managed with open reconstruction.

Iatrogenic-related transplant injuries: the role of the interventional radiologist

As advances in surgical techniques and postoperative care continue to improve outcomes, the use of solid organ transplants as a treatment for end-stage organ disease is increasing. With the growing population of transplant patients, there is an increasing need for radiologic diagnosis and minimally invasive procedures for the management of posttransplant complications. Typical complications may be vascular or nonvascular. Vascular complications include arterial stenosis, graft thrombosis, and development of fistulae. Common nonvascular complications consist of leaks, abscess formation, and stricture development. The use of interventional radiology in the management of these problems has led to better graft survival and lower patient morbidity and mortality. An understanding of surgical techniques, postoperative anatomy, radiologic findings, and management options for complications is critical for proficient management of complex transplant cases. This article reviews these factors for kidney, liver, pancreas, islet cell, lung, and small bowel transplants.

Urological Consequences following Renal Transplantation: A Review of the Literature

Renal transplant (RT) represents the treatment of choice for end-stage renal disease (ESRD) but harbours a wide range of possible complications and therapeutic challenges of urological competence. Dialysis years and clinical medical background of these patients are risk factors for sexual dysfunction and lower urinary tract symptoms (LUTS). On the contrary, RT itself may have a number of possible surgical complications such as ureteral stenosis and urinary leakage, while immunosuppressive treatment is a known risk factor for de-novo malignancies.

The present review describes the main urologic problems of RT patients and their up-to-date treatment options according to the most recently available literature evidences.

Ureteric reconstruction for the management of transplant ureteric stricture: a decade of experience from a single centre

This study was conducted to review the outcomes of patients who had undergone surgical repair of a ureteric stricture following renal transplantation. All patients who developed a ureteric stricture and underwent ureteric reconstruction following renal transplantation, between December 2003 and November 2013, were reviewed. One thousand five hundred and sixty renal transplants were performed during the study period. Forty patients required surgical repair of a ureteric stricture (2.5%, 25 male, median age 48 [14-78]). The median time to stricture was 3 [1-149] months. 19 patients were reconstructed by reimplantation to the bladder, 18 utilized a Boari flap, two were a pre-existing ileal conduit and one was an anastomosis to a native ureter. In one patient, reconstruction was impossible and consequently an extra-anatomic stent was used. Two patients required re-operation for restricture and kinking. Median serum creatinine at 12 months following surgery was 148 [84-508] μmol/l. There was no 90-day mortality. Eleven grafts were lost at the time of this study, a median time of 11 [1-103] months after reconstruction. The incidence of ureteric stricture following renal transplant is low. Surgical reconstruction of the transplant ureter is the optimal treatment and is successful in the majority of patients.

Ureteral obstruction following renal transplantation: causes, diagnosis and management

Renal transplantation, first performed successfully in the 1950s, is the treatment of choice for most patients with end-stage renal failure. It confers longer term survival and a better quality of life than do both haemodialysis and peritoneal dialysis. The success of renal transplantation is dependent on the preservation of renal graft function and despite the many advances in surgical techniques, immunosuppressive regimens and supportive therapies, many challenges remain including post-operative ureteral obstruction. This complication can pose a risk to graft, and, occasionally, to patient survival. In this pictorial review, we describe the causes of ureteral obstruction following renal transplantation and illustrate the pivotal role of radiology in both diagnosing and managing these complications.

Outcomes of Percutaneous Management of Anastomotic Ureteral Strictures in Renal Transplantation: Chronic Nephroureteral Stent Placement with and without Balloon Dilatation

PURPOSE

This study was designed o evaluate outcomes of percutaneous management of anastomotic ureteral strictures in renal transplants using nephroureteral stents with or without balloon dilatation.

METHODS

A retrospective audit of 1,029 consecutive renal transplants was performed. Anastomotic ureteral strictures were divided into two groups: nephroureteral stent only (NUS) and NUS+PTA (nephroureteral stent plus percutaneous transluminal angioplasty), with each cohort subdivided into early versus late presentation (obstructive uropathy occurring <90 day or >90 days from transplant, respectively). Overall and 6-month technical success were defined as removal of NUS any time with <30 % residual stenosis (any time lapse less or more than 6 months) and at >6 months, respectively. Patency was evaluated from NUS removal to last follow-up for both groups and compared.

RESULTS

Sixty-seven transplant patients with 70 ureteric anastomotic strictures (6.8 %, n = 70/1,029) underwent 72 percutaneous treatments. 34 % were late (>90 days, n = 24/70), and 66 % were early (<90 days, n = 46/70). Overall technical success was 82 % (n = 59/72) and 6-month success was 58 % (n = 42/72). Major and minor complications were 2.8 % (n = 2/72), and 12.5 % (n = 9/72). NUS+PTA did not improve graft survival (p = 0.354) or patency (p = 0.9) compared with NUS alone. There was no difference in graft survival between treated and nontreated groups (p = 0.74).

CONCLUSIONS

There is no advantage to PTA in addition to placement of NUS, although PTA did not negatively impact graft survival or long-term patency and both interventions were safe and effective. Neither the late or early groups benefited from PTA in addition to NUS. Earlier obstructions showed greater improvement in serum creatinine than later obstructions.

The accordion sign in the transplant ureter: ramifications during balloon dilation of strictures

PURPOSE

This study was designed to demonstrate the accordion sign within the transplant ureter and evaluate its ramifications during balloon dilation of strictures.

METHODS

A retrospective electronic chart and imaging review included demographic characteristics, procedure reports, and complications of 28 renal transplant patients having ureteral strictures treated with percutaneous balloon dilation reported in our transplant nephrology database during an 8-year period. The accordion sign was deemed present or absent on the basis of an imaging review and was defined as present when a tortuous ureter became kinked and irregular when foreshortened after placement of a wire or a catheter. Procedure-related urine leaks were categorized as occurring at the stricture if within 2 cm; otherwise, they were considered away from the stricture.

RESULTS

The accordion sign was associated with a significantly greater occurrence of leaks away from the stricture (P = 0.001) but not at the stricture (P = 0.34).

CONCLUSIONS

The accordion sign is an important consideration when performing balloon dilation procedures on transplant ureteral strictures, given the increased risk of leak away from the stricture. Its presence should prompt additional care during wire and catheter manipulations.

The current role of endourologic management of renal transplantation complications

Introduction. Complications following renal transplantation include ureteral obstruction, urinary leak and fistula, urinary retention, urolithiasis, and vesicoureteral reflux. These complications have traditionally been managed with open surgical correction, but minimally invasive techniques are being utilized frequently. Materials and Methods. A literature review was performed on the use of endourologic techniques for the management of urologic transplant complications. Results. Ureterovesical anastomotic stricture is the most common long-term urologic complication following renal transplantation. Direct vision endoureterotomy is successful in up to 79% of cases. Urinary leak is the most frequent renal transplant complication early in the postoperative period. Up to 62% of patients have been successfully treated with maximal decompression (nephrostomy tube, ureteral stent, and Foley catheter). Excellent outcomes have been reported following transurethral resection of the prostate shortly after transplantation for patients with urinary retention. Vesicoureteral reflux after renal transplant is common. Deflux injection has been shown to resolve reflux in up to 90% of patients with low-grade disease in the absence of high pressure voiding. Donor-gifted and de novo transplant calculi may be managed with shock wave, ureteroscopic, or percutaneous lithotripsy. Conclusions. Recent advances in equipment and technique have allowed many transplant patients with complications to be effectively managed endoscopically.

Retrograde endoureterotomy for persistent ureterovesical anastomotic strictures in renal transplant kidneys after failed antegrade balloon dilation

OBJECTIVE

To evaluate the long-term outcomes and complications of retrograde endoureterotomy for persistent ureterovesical anastomotic strictures in renal transplant patients after percutaneous balloon dilation failure.

METHODS

From January 2000 to May 2010, 26 (2.6%) of 1004 renal transplant patients developed ureterovesical anastomotic stricture after surgery. Seven of these patients and five additional referred patients with similar characteristics were treated with retrograde endoureterotomy after ≥1 previous unsuccessful attempt at percutaneous balloon dilation. All strictures treated were <1 cm in length. The clinical characteristics and outcomes were analyzed. Success was defined as the absence of symptoms and the resolution of obstruction on imaging after the procedure.

RESULTS

The median interval from initial treatment to endoureterotomy was 2.9 months (range 1.3-62.1). Before endoscopic treatment, 8 patients (67%) were treated with a single trial of balloon dilation and 4 (33%) with multiple trials. Endoureterotomy was performed using cold knife, holmium:yttrium-aluminum-garnet laser, and Bugbee electrode in 9, 2, and 1 patients, respectively. The median follow-up period was 44.4 months (range 2.4-68.6). Recurrent stricture developed in 2 patients during a mean follow-up of 4.7 months. Thus, the overall success rate was 83%. Postoperative complications appeared in 3 patients (25%) with culture-positive urinary tract infection. One graft failure occurred but was not related to a recurrent stricture.

CONCLUSION

After failure of antegrade percutaneous balloon dilation, retrograde endoureterotomy is an effective salvage procedure for well-selected cases of renal transplant patients with a short ureterovesical anastomotic stricture.

Ureteropyelostomy using the native ureter for the management of ureteric obstruction or symptomatic reflux following renal transplantation

OBJECTIVE

To evaluate the outcome of ureteropyelostomy using the native ureter for the management of ureteric obstruction or symptomatic reflux after renal transplantation.

MATERIALS AND METHODS

This is a single-center retrospective review of consecutive patients who underwent ureteropyelostomy after renal transplantation between the years 2000 and 2009. Ureteropyelostomy was performed using the ipsilateral native ureter. The native kidney was not removed. Patients' baseline characteristics, preceding interventions, and postprocedural outcomes were analyzed.

RESULTS

Ten patients underwent ureteropyelostomy after renal transplantation. All had initial Lich Gregoir ureterovesical anastomosis. Reasons for the reconstructive surgery were transplant ureteric stenosis in 8 patients or vesicoureteric reflux causing recurrent graft pyelonephritis in 2 patients. Median follow-up was 53 months (range 24-76). Postoperative complications included 3 patients who had transient anastomotic obstruction after removal of the double pigtail stent. They were managed with short-term ureteric restenting or nephrostomy tube insertion. In addition, 2 patients required delayed ipsilateral native nephrectomy because of infection. At last follow-up, all grafts remained unobstructed and free of infections.

CONCLUSION

Ureteropyelostomy using the native ureter for the management of transplant ureteric obstruction or symptomatic reflux is safe and provides good long-term preservation of graft function in selected patients.

Endourological management of ureteric strictures after kidney transplantation: Stenting the stent

The incidence of ureteric obstruction after kidney transplantation is 3–12.4%, and the most common cause is ureteric stenosis. The standard treatment remains open surgical revision, but this is associated with significant morbidity and potential complications. By contrast, endourological approaches such as balloon dilatation of the ureter, ureterotomy or long-term ureteric stenting are minimally invasive treatment alternatives. Here we discuss the available minimally invasive treatment options to treat transplant ureteric strictures, with an emphasis on long-term stenting. Using an example patient, we describe the use of a long-term new-generation ureteric metal stent to treat a transplant ureter where a mesh wire stent had been placed 5 years previously. The mesh wire stent was heavily encrusted throughout, overgrown by urothelium and impossible to remove. Because the patient had several previous surgeries, we first considered endourological solutions. After re-canalising the ureter and mesh wire stent by a minimally invasive procedure, we inserted a Memokath® (PNN Medical, Kvistgaard, Denmark) through the embedded mesh wire stent. This illustrates a novel method for resolving the currently rare but existing problem of ureteric mesh wire stents becoming dysfunctional over time, and for treating complex transplant ureteric strictures.

Percutaneous management of ureteral stenosis of transplanted kidney: technical and clinical aspects

In the field of renal transplantation, advances in the management of graft rejection have led to improved graft and patient survival rates, however other types of complications have now become more apparent, e.g. vascular or urological. The most common urological complications following renal transplantation are ureteral stenosis or obstruction, constituting a significant problem of the renal graft's survival. The most important aspects concerning these complications are early diagnosis and prompt treatment since any delay in their management may lead to renal graft dysfunction or even graft loss. Developments in interventional radiology have provided minimally invasive means to treat urological complications with low complication rates. Herein we review the literature in order to evaluate the efficacy of percutaneous management of ureteral stenosis regarding its safety, immediate and long-term results, complications as well as rate of recurrence.

Retrograde balloon dilation >10 weeks after renal transplantation for transplant ureter stenosis - our experience and review of the literature

Objective

Despite many efforts to prevent ureteric stenosis in a transplanted kidney, this complication occurs in 3–5% of renal transplant recipients. Balloon dilatation (BD) is a possible minimally invasive approach for treatment, but reports to date refer only to the antegrade approach; we analysed our experience with retrograde BD (RBD) and reviewed previous reports.

Patients and methods

From October 2008 to February 2011, eight patients after renal transplantation (RTX) underwent RBD for transplant ureteric stenosis at our hospital. We retrospectively analysed the outcome and reviewed previous reports.

Results

The eight recipients (five men and three women; median age 55 years, range 38–69) were treated with one or two RBDs for transplant ureteric stenosis. There were no complications. The median (range) time after RTX was 4.5 (2.5–11) months. Long-term success was only achieved in one recipient, while five patients were re-operated on (three with a new implant, two by replacement of transplanted ureter with ileum) after a median (range) of 2.8 (0.7–7.0) months after unsuccessful RBD(s). For two recipients the success remained unclear (one graft loss due to other reasons, one result pending). When the first RBD was unsuccessful there was no improvement with a second.

Conclusion

RBD is technically feasible, but our findings and the review of previous reports on antegrade ureteric dilatation suggest that the success rate is low when the ureter is dilated at ⩾10 weeks after RTX. From our results we cannot recommend RBD for transplant ureteric stenosis at ⩾10 weeks after RTX, while previous reports show favourable results of antegrade BD in the initial 3 months after RTX.

Ureteral complications in renal transplant recipients successfully treated with interventional radiology

INTRODUCTION

Ureteral complications in renal transplantation occur in approximately 8% of renal transplant recipients, occasionally leading to graft loss. This retrospective study presents a single-center experience in managing ureteral complications with interventional radiology as well as the long-term graft function and recipient survival.

PATIENTS AND METHODS

We analyzed 21 renal transplant recipients with ureteral problems.

RESULTS

Nine patients experienced urinary leak, six patients had ureteric obstruction, and six patients had obstruction preceded by leak. Median recipient age was 48 (range, 20-63) years; 71% (15/21) of the patients were male and 66.6% (14/21) of transplants were derived from cadaveric donors. Ureteral complications were diagnosed at a mean of 18 days (range, 12-47) after renal transplantation. Initially a percutaneous nephrostomy was performed, followed by antegrade placement of a nephroureteral stent. In cases with ureteral obstruction, ureteral balloon dilation was performed prior to placement of the stent. Median time to the procedure was 53 days, and median follow-up for the purposes of this study was 57 months. Renal graft function improved following treatment of the ureteral complication. Mean serum creatinine values prior to and after the intervention were 4.8 +/- 2.12 and 1.79 +/- 0.58 mg/dL, respectively (P < .0001). Functional renal grafts were observed at the first, third, and fifth posttransplantation year among 100%, 95.2% and 80.9% of patients, respectively. It should be further noted that no graft was lost due to a ureteral complication.

CONCLUSIONS

Interventional radiology was successful in treating immediate and long-term ureteral problems among renal transplant recipients with preservation of good renal function and patient survival.

Endoscopic incision for obstruction of vesico-ureteric anastomosis in transplanted kidneys

OBJECTIVE

To report our experience of endoscopic incision for obstruction of vesico-ureteric anastomosis (VUA) in transplanted kidneys.

PATIENTS AND METHODS

Between February 2001 and March 2006, six men and two women (mean age 38 years, range 27-57) with VUA obstruction in their transplanted kidneys were treated by percutaneous nephrostomy and endoscopic incision. After the anastomosis was completely cut, two JJ stents were placed in the ureter for 4-6 weeks. During the follow-up, serum urea, creatinine and uric acid levels were measured, and urine culture, ultrasound examination and washout renal scintigraphy were performed every month for the first 6 months, then every 3 months.

RESULTS

In all, 12 procedures of endoureterotomy were performed and all procedures resulted in successful incision of the obstruction. There were no complications during or after the procedures. The retrograde and antegrade endoureterotomies were performed with four procedures in two patients and eight procedures in six patients, respectively. At a mean (range) follow-up of 16 (4-45) months, five of the eight patients had ureteric patency and stable renal function. In three patients there was a recurrence of obstructive uropathy, immediately after JJ stent removal, which finally required open surgical correction.

CONCLUSIONS

Percutaneous nephrostomy and endoscopic incision is safe and effective for obstruction of VUA in transplanted kidney, and it can be the initial therapy for ureteric obstruction in transplanted kidneys; however, open surgical reconstruction should be considered if the initial endoscopic incision procedure fails.

Percutaneous therapy of ureteral obstructions and leak after renal transplantation: long-term results

The purpose of this study was to evaluate the long-term outcome of percutaneous therapy of ureteral complications after renal transplantation. Between January 2000 and June 2006 we percutaneously treated 26 renal transplant patients with ureteral obstruction (n=19) and leak (n=7). Obstructions were classified as early (<2 months after transplantation) or late (>2 months). Patients with leak were treated with nephro-ureteral catheter placement and subsequent double-J stenting. Balloon dilatation, stent placement, and basket extraction were used to treat ureteral obstructions. Patients were followed with ultrasonography. No major procedure-related complication occurred. The mean follow-up time was 34.3 months (range: 6 to 74 months). Initial clinical success was achieved in all 19 patients with obstruction and 6 of 7 patients with leak. Four of 9 early obstructions and 4 of 10 late obstructions recurred during the follow-up. All recurrences were initially managed again with percutaneous methods, including cutting balloon technique and metallic stent placement. Although there was no recurrence in patients with successfully treated leak, stricture was seen at the previous leak site in two patients. These strictures were also successfully managed percutaneously. We conclude that in the treatment of ureteral obstruction and leak following renal transplantation, percutaneous therapy is an effective alternative to surgery. However, further interventions are usually needed to maintain long-term patency.