Ureteral complications in renal transplant recipients successfully treated with interventional radiology

Emergency endovascular and percutaneous urological interventions: A pictorial review

Emergency endovascular and percutaneous urological interventions encompass various diagnostic and therapeutic procedures to address various genitourinary conditions. These urological interventions are life-saving in addressing complications following biopsy, post-nephrectomy, post-transplant, and post-trauma. Compared to other surgical fields, there are relatively fewer urological emergencies. However, they require prompt radiological diagnosis and urgent interventions. This pictorial essay emphasizes various urological emergencies and urgent interventional management.

Interventional Management of Vascular Complications after Renal Transplantation

BACKGROUND

 Kidney transplantations are increasing due to demographic changes and are the treatment of choice for end-stage renal disease. Non-vascular and vascular complications may occur in the early phase after transplantation and at later stages. Overall postoperative complications after renal transplantations occur in approximately 12 % to 25 % of renal transplant patients. In these cases, minimally invasive therapeutic interventions are essential to ensure long-term graft function. This review article focuses on the most critical vascular complications after renal transplantation and highlights current recommendations for interventional treatment.

METHOD

 A literature search was performed in PubMed using the search terms "kidney transplantation", "complications", and "interventional treatment". Furthermore, the 2022 annual report of the German Foundation for Organ Donation and the EAU guidelines for kidney transplantation (European Association of Urology) were considered.

RESULTS AND CONCLUSION

 Image-guided interventional techniques are favorable compared with surgical revision and should be used primarily for the treatment of vascular complications. The most common vascular complications after renal transplantation are arterial stenoses (3 %-12.5 %), followed by arterial and venous thromboses (0.1 %-8.2 %) and dissection (0.1 %). Less frequently, arteriovenous fistulas or pseudoaneurysms occur. In these cases, minimally invasive interventions show a low complication rate and good technical and clinical results. Diagnosis, treatment, and follow-up should be performed in an interdisciplinary approach at highly specialized centers to ensure the preservation of graft function. Surgical revision should be considered only after exhausting minimally invasive therapeutic strategies.

KEY POINTS

  · Vascular complications after renal transplantation occur in 3 % to 15 % of patients.. · Image-guided interventional procedures should be performed primarily to treat vascular complications of renal transplantation.. · Minimally invasive interventions have a low complication rate with good technical and clinical outcomes..

CITATION FORMAT

· Verloh N, Doppler M, Hagar MT et al. Interventional Management of Vascular Complications after Renal Transplantation. Fortschr Röntgenstr 2023; DOI: 10.1055/a-2007-9649.

Recommendations for living donor kidney transplantation

This Guide for Living Donor Kidney Transplantation (LDKT) has been prepared with the sponsorship of the Spanish Society of Nephrology (SEN), the Spanish Transplant Society (SET), and the Spanish National Transplant Organization (ONT). It updates evidence to offer the best chronic renal failure treatment when a potential living donor is available. The core aim of this Guide is to supply clinicians who evaluate living donors and transplant recipients with the best decision-making tools, to optimise their outcomes. Moreover, the role of living donors in the current KT context should recover the level of importance it had until recently. To this end the new forms of incompatible HLA and/or ABO donation, as well as the paired donation which is possible in several hospitals with experience in LDKT, offer additional ways to treat renal patients with an incompatible donor. Good results in terms of patient and graft survival have expanded the range of circumstances under which living renal donors are accepted. Older donors are now accepted, as are others with factors that affect the decision, such as a borderline clinical history or alterations, which when evaluated may lead to an additional number of transplantations. This Guide does not forget that LDKT may lead to risk for the donor. Pre-donation evaluation has to centre on the problems which may arise over the short or long-term, and these have to be described to the potential donor so that they are able take them into account. Experience over recent years has led to progress in risk analysis, to protect donors' health. This aspect always has to be taken into account by LDKT programmes when evaluating potential donors. Finally, this Guide has been designed to aid decision-making, with recommendations and suggestions when uncertainties arise in pre-donation studies. Its overarching aim is to ensure that informed consent is based on high quality studies and information supplied to donors and recipients, offering the strongest possible guarantees.

Long-term outcomes of paclitaxel-coated balloons for non-malignant ureteral strictures

PURPOSE

To evaluate the clinical efficacy and safety of drug-coated balloon (DCB) ureteroplasty for the management of non-malignant ureteral strictures.

MATERIAL AND METHODS

A prospective "off-label" monocentric single-arm pilot study investigating the safety and efficacy of drug-coated balloon (DCB) (Lutonix^®; BD, USA) was performed. Twenty-five patients with benign ureteral strictures related to uretero-enteric anastomosis (n = 13); lithiasis (n = 5), post-surgical complications (iatrogenic n = 5), transplanted kidney (n = 1) and post-radiotherapy (n = 1) were included. Following lesion crossing, predilatation was performed using 4-7 mm high-pressure balloon catheter (5-6Fr) with a balloon pressure of 6-7 atm based on the manufacturer's recommendation. In the absence of rupture of the ureteral wall, the DCB was dilated for 4 min. across the lesion. The process was repeated if deemed necessary to a maximum of three stricture dilatations. We analysed both clinical and radiological primary patency (no signs of ipsilateral hydronephrosis or improvement of the existing residual dilatation at the follow-up examinations) and secondarily safety endpoints.

RESULTS

Mean lesion length was 40 ± 28.5 mm. Mean time follow up was 36 months ± 10.46 months. Strictures were located at upper ureteric (12%), lower ureteric (32%), ureterovesical anastomosis (4%) and uretero-enteric anastomosis (52%) levels. The overall radiological success at 1-year follow-up was 88% (22/25 patients). In 56% patients (14/25 patients with primary patency) the nephrostomy catheter was removed 21 days following a single DCB procedure. In 32% (8/25 patients) an additional dilatation sessions were required for maintaining the ureteral patency. The overall failure rate at 1-year follow-up was 12% (3/25 patients). Only one case of febrile urinary tract infection in a female patient (acute pyelonephritis) was encountered after the first dilatation.

CONCLUSIONS

Paclitaxel-coated balloon ureteroplasty proved to be safe and effective for the treatment of non-malignant ureteral strictures. Larger studies are warranted to validate these promising initial results.

Transplant Ureteral Stenosis after Renal Transplantation: Risk Factor Analysis

INTRODUCTION

The results of kidney transplants have improved dramatically in recent years, leading to reduced morbidity and mortality. Despite continuous improvements, urological complications occur at a rate of 2.6%-15%. Ureteral stenosis of graft ureters is the most common complication, with a probability of 0.5%-6.3%. This study aimed to determine the incidence of ureteral stenosis after kidney transplantation and identify risk factors that distinguish transplant patients with and without ureteral stenosis.

METHODS

This study retrospectively analyzed patients who had undergone kidney transplantation at the Department of Urology of the Friedrich-Alexander University Erlangen-Nuremberg between 2001 and 2015. Forty-seven patients developed ureteral stenosis during the operation. Most of the ureteral stenosis cases occurred in the first 4 months after transplantation. Kaplan-Meier analysis and the log-rank test were used to calculate the cumulative risk, and the Mann-Whitney U test was used nonparametrically. The significance level was set at p < 0.05.

RESULTS

Statistical analysis showed that residual diuresis (p = 0.008), cold ischemia time (CIT) (p = 0.040), the body mass index (p = 0.027), and donor serum creatinine value (p = 0.039) showed a significantly different distribution between recipients with or without ureteral stenosis after kidney transplantation. In multivariate Cox's regression modeling, residual diuresis and the donor serum creatinine level were identified as the only independent predictors of patients' stenosis-free survival.

CONCLUSION

Urological complications not diagnosed and treated in time endanger the success of kidney transplantation. After evaluating the kidney transplantation data of the patients at the Transplant Center Erlangen-Nuremberg from 2001 to 2015, residual diuresis, CIT, the body mass index, and donor serum creatinine value were found to influence the development of ureteral stenosis.

Identifying Early Extraperitoneal High-Volume Urine Leak Post Kidney Transplantation

Transplant clinicians need to be watchful of several potential surgical complications in the early post-transplant period, including haemorrhage, extraperitoneal urine leak, and lymphocele. While haemorrhage and extraperitoneal urine leak usually present in the early post kidney transplant period, lymphoceles usually present 2–6 weeks after transplantation. While the colour and volume of the drained fluid can give some indication of the problem, is not enough evidence for a confident urine leak diagnosis. Further investigations, such as serum biochemical parameter analysis of the drained fluid and ultrasonography, help to identify the true cause. This paper discusses how to identify high-volume extraperitoneal urine leaks in the early post kidney transplant period and considers the differential diagnoses. Different ureteroneocystostomy procedures, including the Lich–Grégoir, Politano–Leadbetter, and U-stitch techniques, are discussed and compared regarding complication rates (especially urine leak and haematuria). The authors also address the management of low- and high-volume extraperitoneal urine leak, the follow-up needed, and the impact of urine leak on graft and patient survival, length of hospital stay, and rate of hospital readmission.

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.

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.

Minimally invasive approach for the management of urological complications after renal transplantation: single center experience

BACKGROUND

The aim of the study was to characterise urological complications after renal transplantation and to evaluate the role of minimally invasive management for urological complications.

METHODS

A total of 920 kidney transplantations were performed between 2008 and 2015. All patients were followed up for at least 1 year after transplantation. Complications regarded as urological were urinary leakage, ureteral stricture, urinary malignancy, bladder outlet obstruction (BOO) and urinary calculi. We evaluated data from the time of occurrence of urological complications and the type of the management prescribed.

RESULTS

Among 920 transplantations performed in our clinic, 41 (4.4%) urological complications arose. Twenty (48.8%) of the complications occurred during the first 3 months and 21 (51.2%) occurred after 3 months, postoperatively. Ureteral strictures were found in 14 (34.1%) patients, urinary tract stones in seven (17%), BOO in 6 (14.6%) and urinary leakage was observed in 5 (12.1%) patients. Ureteral stricture was managed with endoscopic approach in eight (61.3%) patients. Urinary tract stones and urinary leakage were managed in 7 (100%) and 4 (75%) patients with endoscopic approach. Overall 29 (70.7%) of 41 urological complications were managed with endourological approaches.

CONCLUSIONS

It is likely that the importance of open surgery could decrease in the future. Endoscopic management of urological complications have come to have an important role in the treatment of urological complications after transplantation.

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.

Interventional radiological treatment of renal transplant complications: a pictorial review

Renal transplantation is the treatment of choice for patients with chronic renal failure, which produces a dramatic improvement in the quality of life and survival rates, in comparison to long-term dialysis. Nowadays, new imaging modalities allow early diagnosis of complications, and thanks to the recent developments of interventional techniques, surgery may be avoided in most cases. Knowledge in the types of renal transplant complications is fundamental for a correct pre-operative planning. In this article, we described the most common or clinically relevant renal transplant complications and explained their interventional management.

Ureteral strictures revisited…trying to see the light at the end of the tunnel: a comprehensive review

A ureteral stricture is a rather rare urological event defined as a narrowing of the ureter causing a functional obstruction and renal failure, if left untreated. The aim of this review article is to summarize and discuss current knowledge on the incidence, pathogenesis, management, and follow up of proximal, mid, and distal ureteral strictures.

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 first use of Resonance(®) metallic ureteric stent in a case of obstructed transplant kidney

INTRODUCTION

To date, double JJ stent is the mainstay ureteric stent used in a transplant kidney. We herein report the first use of Resonance(®) metallic ureteric stent to manage ureteric obstruction in a transplant kidney.

PRESENTATION OF CASE

A 45-year-old lady underwent an uneventful living related donor renal transplantation. Due to post-operative pelvi-ureteric obstruction and recurrent obstruction following multiple distal stent migration and expulsion necessitated frequent nephrostomy insertion and antegrade stenting, she underwent challenging but successful retrograde insertion of a 12 centimetres long and size 6.0 French Cook Resonance(®) metallic ureteric stent which was performed under general anaesthesia.

DISCUSSION

Metallic ureteric stents are a fairly recent introduction to modern urology and they have been successfully used in the management of benign and malignant obstruction of ureter.

CONCLUSION

This is the first case of therapeutic metallic ureteric stent insertion in a transplant kidney.

Removal of foley catheters in live donor kidney transplant recipients on postoperative day 1 does not increase the incidence of urine leaks

Catheterization of the urinary bladder during kidney transplantation is essential. The optimal time to remove the Foley catheter postoperatively is not universally defined. It is our practice to remove the Foley catheter on postoperative day 1 in live donor kidney transplant recipients who meet our standardized protocol criteria. We believe that early removal of Foley catheters increases patient comfort and mobility, decreases the risk of catheter associated urinary tract infections, and allows for decreased hospital length of stay. The hypothetical risk of early removal of Foley catheters would be the increased risk of urine leak. We reviewed 120 consecutive live donor kidney transplant recipients and found that there was not an increased incidence of urine leaks in patients whose Foley catheters were removed on postoperative day 1.

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.