Role of percutaneous urinary diversion in malignant and benign obstructive uropathy

Percutaneous Nephrostomy as a Procedure in the Treatment of Urinary Tract Obstruction - Experiences in the University Clinic of Urology in Skopje

INTRODUCTION

Obstructive uropathy encompasses various urinary tract obstructions, leading to changes in urine flow, kidney pressure, and impaired kidney function. Predicting renal recovery from obstructive uropathy, can be challenging and necessitates treatment, as in percutaneous nephrostomy (PNS) drainage. The choice of drainage method depends on patient-specific factors and local expertise. According to the data for the Republic of North Macedonia, in the register of the European Renal Association, in the last few years, there has been an increase in the percentage of patients with obstructive nephropathy from 7.6% to 8.9% who end up on a chronic hemodialysis program. Prompt relief from urinary tract obstruction is essential to preserve renal function and prevent complications. The aim of this study is to present our initial data analysis of recent experience in the use of nephrostomies as a method for temporary or long-term resolution of obstructive nephropathy, in terms of safety and success in preserving kidney function and reducing the number of patients on hemodialysis.

MATERIALS AND METHODS

This study analyzed the medical records of 24 patients with obstructive uropathy who underwent PNS placement. Data were collected for the type and degree of obstruction from the ultrasonographic examination. A pig tail nephrostomy was used, with a dilator, guided under ultrasound and controlled with contrast and fluoroscope. Obstructive nephropathy was defined as an elevation of the serum creatinine > 109 µmol/L, before the intervention. Glomerular filtration rate (GFR) was calculated according to the formula CKD epi in ml/min. Each placement of the PNS was considered as an individual procedure and the data of 38 placed nephrostomies were analyzed. We compared the laboratory analyses from the day before (D0) PNS placement and on the seventh day (D7) after PNS placement. The reduction of values for red blood cells (RBC) and hemoglobin (Hb) baseline values from D0 to D7 and the need for transfusion after the procedure were defined as a complication-bleeding. The increase in total counts of the white blood cells (WBC) and C-reactive protein (CRP) from the baseline values from D0 to D7 were defined as a complication-infection. Standard statistical methods were used for data processing.

RESULTS

Most patients, 17 (70%), had malignant disease as the cause of obstruction. Unilateral obstruction was more common, detected in 24 (63%) of procedures, with a high degree of hydronephrosis. Obstructive nephropathy, marked by elevated serum creatinine, was observed in 23 (60%) cases before PNS placement. Complications included bleeding and infection but did not result in any fatalities. When comparing the laboratory analysis before PNS placement (D0) and seven days later (D7), a statistically significant decrease in serum creatinine (225±161 vs. 162±145, p=0.005) and an increase in GFR (47±39 vs.59±34, p= 0.005) were observed.

CONCLUSION

Percutaneous nephrostomy is a safe and effective treatment option for urinary tract obstruction, especially in patients with malignancies. Continuous monitoring is essential to assess long-term complications and the longevity of PNS functionality. This procedure offers a significant benefit in preserving renal function and minimizing the need for hemodialysis in these patients.

Serum creatinine trajectory after drainage of kidneys with bilateral malignant ureteral obstruction: a prospective non-randomized comparative study

BACKGROUND

Serum creatinine trajectory (SCr-Tr) is a neglected prognostic tool for chronic and acute kidney injury. We aimed to assess the predictors of SCr-Tr during the time-to-nadir and serum creatinine (SCr) normalization rate after drainage, using percutaneous nephrostomy in patients with bilateral malignant ureteral obstruction.

METHODS

A prospective non-randomized study was performed on SCr-Tr in patients with bilateral malignant ureteral obstruction from August 2019 to March 2022. The primary outcome was SCr-Tr during the time-to-nadir.

RESULTS

This study included 102 patients with a mean age ± SD of 59.6 ± 14.7 years. SCr-Tr was non-linear with a mean ± SD (range) of 0.5 ± 0.4 (0.03-2.3) mg/dl/day. Multivariate analyses revealed that female gender (p = 0.016), body mass index (BMI; p = 0.005), and SCr at presentation (p < 0.001) were predictors of rapid SCr-Tr during the time-to-nadir. However, age (p = 0.008) and low urine output at presentation (p = 0.015) were associated with a lower SCr-Tr. In contrast, laterality of drainage (p = 0.544) and mean parenchymal thickness (p = 0.066) were not associated with mean SCr-Tr. Also, only the mean parenchymal thickness (p = 0.002) was a predictor of rapid SCr-Tr at ≥ 0.5 mg/dl/day. However, low BMI (p = 0.023) was associated with a high SCr normalization rate, while unilateral drainage (p = 0.045) was associated with a lower rate.

CONCLUSIONS

Female gender, low BMI, and SCr at presentation were predictors of rapid SCr-Tr during the time-to-nadir. Bilateral drainage was an independent predictor of SCr normalization rate, but not of rapid SCr-Tr. The mean parenchymal thickness was the only independent predictor for rapid SCr-Tr at ≥ 0.5 mg/dl/day.

Acute kidney injury due to bilateral malignant ureteral obstruction: Is there an optimal mode of drainage?

There is a well-known relationship between malignancy and impairment of kidney functions, either in the form of acute kidney injury or chronic kidney disease. In the former, however, bilateral malignant ureteral obstruction is a surgically correctable factor of this complex pathology. It warrants urgent drainage of the kidneys in emergency settings. However, there are multiple controversies and debates about the optimal mode of drainage of the bilaterally obstructed kidneys in these patients. This review addressed most of the concerns and provided a comprehensive presentation of this topic from the recent literature. Also, we provided different perspectives on the management of the bilateral obstructed kidneys due to malignancy. Despite the frequent trials for improving the success rates and functions of ureteral stents, placement of a percutaneous nephrostomy tube remains the most recommended tool of drainage due to bilateral ureteral obstruction, especially in patients with advanced malignancy. However, the disturbance of the quality of life of those patients remains a major unresolved concern. Beside the unfavorable prognostic potential of the underlying malignancy and the various risk stratification models that have been proposed, the response of the kidney to initial drainage can be anticipated and evaluated by multiple renal prognostic factors, including increased urine output, serum creatinine trajectory, and time-to-nadir serum creatinine after drainage.

Predictors of nadir serum creatinine after drainage of bilaterally obstructed kidneys due to different etiologies

PURPOSE

To identify the predictors of nadir serum creatinine (SCr) after drainage of bilaterally obstructed kidneys (BOKs) by different modes: double-J stent (JJ) versus percutaneous nephrostomy (PCN) and unilateral versus bilateral drainage.

METHODS

A prospective non-randomized study was performed on patients with BOKs and raised SCr during December 2019-November 2021. Relevant variables were studied for improvement and non-improvement and for benign and malignant underlying obstructions (BUO and MUO).

RESULTS

This study included 107 patients with BOKs including 68 (63.6%) males and 39 (36.4%) females. After drainage, 86 (80.4%) patients get improved, while 21 (19.6%) patients failed to reach a nadir SCr. Drainage by PCN was significantly higher in MUO, while JJ was significantly higher in BUO (p < 0.001). Also, bilateral drainage was a significant predictor of improvement in MUO (p = 0.03). In contrast, mode of drainage had no significant effect on improvement in BUO (p = 0.84), but bilateral drainage was a significant factor of rapid time to nadir (p = 0.02). Univariate analyses revealed no significant effects on the improvement in SCr from the studied variables, except the male gender (p = 0.01), old age (p < 0.001), MUO (p = 0.01), unilateral drainage (p < 0.001), and use of PCN for drainage (p < 0.001). By multivariate analysis, unilateral drainage (p = 0.01) and MUO (p < 0.001) were independent predictors of non-improvement in patients with BOKs.

CONCLUSIONS

Male gender, old age, MUO, unilateral drainage, and drainage by PCN were significant predictors of non-improvement in SCr after drainage of BOKs. However, unilateral drainage and MUO were the only independent predictors of non-improvement.

Percutaneous nephrostomy versus retrograde ureteral stenting for acute upper obstructive uropathy: a systematic review and meta-analysis

Acute obstructive uropathy is associated with significant morbidity among patients with any condition that leads to urinary tract obstruction. Immediate urinary diversion is necessary to prevent further damage to the kidneys. In many centres, the two main treatment options include percutaneous nephrostomy (PCN) and retrograde ureteral stenting (RUS). The purpose of this study if to compare the efficacy and safety of PCN and RUS for the treatment of acute obstructive uropathy. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, EMBASE, the World Health Organisation International Clinical Trials Registry Platform and ClinicalTrials.gov. We also searched the reference lists of included studies to identify any additional trials. We included randomised controlled trials and controlled clinical trials comparing the outcomes of clinical improvement (septic parameters), hospitalisation duration, quality of life, urinary-related symptoms, failure rates, post-procedural pain [measured using a visual analogue scale (VAS)] and analgesics use. We conducted statistical analyses using random effects models and expressed the results as risk ratio (RR) and risk difference (RD) for dichotomous outcomes and mean difference (MD) for continuous outcomes, with 95% confidence intervals (CIs). Seven trials were identified that included 667 patients. Meta-analysis of the data revealed no difference in the two methods in improvement of septic parameters, quality of life, failure rates, post-procedural pain (VAS), or analgesics use. Patients receiving PCN had lower rates of haematuria and dysuria post-operatively and longer hospitalisation duration than those receiving RUS. PCN and RUS are effective for the decompression of an obstructed urinary system, with no significant difference in most outcomes. However, PCN is preferable to RUS because of its reduced impact on the patient's post-operative quality of life due to haematuria and dysuria, although it is associated with slightly longer hospitalisation duration.

Clinical Factors Associated With a Short Survival Time After Percutaneous Nephrostomy for Ureteric Obstruction in Cancer Patients: An Updated Model

CONTEXT

Patients with advanced cancer can develop ureteric obstruction. Percutaneous nephrostomy (PCN) tube insertion can relieve this obstruction and prevent renal failure. PCN is associated with complications and can worsen quality of life. Prognostic models of survival after PCN in cancer patients can help identify the patients who will most likely benefit from this intervention. This work updates a prognostic model to predict overall survival in cancer patients after receiving PCN.

OBJECTIVES

The primary objective was to assess survival of patients with malignant urinary obstruction after PCN tube insertion. The secondary objective was to identify factors associated with poor prognosis in this group of patients and externally validate an existing model.

METHODS

We conducted a retrospective analysis of 211 patients who had malignant urinary obstruction and received PCN tube insertion.

RESULTS

The median survival was 5.05 months (95% CI = 3.87-7.11; range 2-963 days). On univariate analysis, the factors significantly associated with shorter survival were type of malignancy, bilateral hydronephrosis, serum albumin <3.5 mg/dL, presence of metastasis, ascites, and pleural effusion (P < 0.05). Multivariate analysis using a Cox proportional hazards regression model showed that type of malignancy, serum albumin <3.5 mg/dL, pleural effusion, and bilateral hydronephrosis were significantly associated with shorter survival (P < 0.05). Using the latter three factors, we stratified patients into four prognostic groups: zero risk factors (32 patients), one risk factor (85 patients), two risk factors (78 patients), and three risk factors (16 patients). Median survival for each group was 17.6 months, 7.7 months, 2.2 months, and 1.7 months, respectively (P < 0.0001).

CONCLUSION

Survival in patients with malignant ureteric obstruction can range widely from a few days to a few years. The presented prognostic model is an updated model and can be used to identify patients with poor survival after PCN.

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.

Percutaneous nephrostomy: technical aspects and indications

First described in 1955 by Goodwin et al as a minimally invasive treatment for urinary obstruction causing marked hydronephrosis, percutaneous nephrostomy (PCN) placement quickly found use in a wide variety of clinical indications in both dilated and nondilated systems. Although the advancement of modern endourological techniques has led to a decline in the indications for primary nephrostomy placement, PCNs still play an important role in the treatment of multiple urologic conditions. In this article, the indications, placement, and postprocedure management of percutaneous nephrostomy drainage are described.

Acute reversible kidney injury secondary to bilateral ureteric obstruction

BACKGROUND

Acute reversible kidney injury (ARKI) secondary to bilateral ureteric obstruction (BUO) is a common urological problem. Our goals were to describe the etiology, management and outcomes of such patients identified between 2006 and 2009 and to compare them with a similar historical study published in 1982.

METHODS

Chart review was performed on 49 patients with AKRI secondary to BUO. ARKI was defined as ≥33% decrease in serum creatinine after intervention. Those with malignant and benign causes of obstruction were identified and management and outcome data were collected.

RESULTS

Of these 49 patients, 83% had BUO secondary to malignancy, 28% of these presenting for the first time. Prevalence of bladder cancer was increased (p = 0.04) and cervix trended lower (p = 0.07) compared with the earlier study; prostate cancer was unchanged (p = 0.51). The average survival was 239 days; 90% of patients died within a year after presenting with BUO from a malignant etiology. Compared with the 1982 group, there were trends towards a decrease in the frequency of retroperitoneal fibrosis (p = 0.08) and an increase in bilateral ureteric calculi (p = 0.16) in the benign group.

CONCLUSIONS

Patients with ARKI secondary to BUO most likely have an underlying malignancy, with almost a third of them being diagnosed for the first time. Prevalence of bladder cancer increased while cervical cancer trended lower. The cause for the former is unclear; the latter may be due to aggressive screening. Prostate cancer remained unchanged despite the widespread implementation of prostate-specific antigen testing. Patients with an underlying malignancy do poorly and those with a newly diagnosed malignancy do worst. Those with ARKI secondary to benign causes did well.

Endourologic management of malignant ureteral obstruction: indications, results, and quality-of-life issues

Obstruction of the upper urinary tract is a problem commonly faced by practicing urologists. The constant evolution in endourology has effectively facilitated minimally invasive management of upper-tract obstruction. In a case in which malignancy is the cause of obstruction, however, the situation significantly changes. Questions arise regarding the need for relieving the obstruction, the means to accomplish this, and the benefits and drawbacks of each technique regarding both their efficacy and their impact on the patients well-being and the crucial issue of quality of life in the face of malignancy.

Percutaneous Nephrostomy and Ureteric Stent Insertion for Acute Renal Deobstruction Consensus Based Guidance

Objective:

Ureteric obstruction can be relieved by either percutaneous nephrostomy (PCN) or retrograde ureteric stenting (RUS). Both are associated with variable technical success, complication rates, availability and quality of life issues. Our aim was to generate guidelines for PCN, RUS and the general approach of renal deobstruction in the UK.

Materials and Methods:

Subsequent to a pilot study, a formal postal questionnaire regarding the indication and method of renal deobstruction was sent via the BAUS audit office to members of BAUS, BSIR, BSUR. Data from 227 radiologists and urologists were categorised into areas of “clear agreement” (>75% agreement), “broad agreement” (50–75% agreement) and “no broad consensus” (less than 50% agreement) for any particular method of management.

Results:

In septic patients with renal obstruction, there was “clear agreement” for urgent deobstruction by PCN. If uncorrectable coagulopathy exists then RUS was the preferred option. There was “clear agreement” that patients with acute or chronic renal failure should be deobstructed during working hours if not septic, with “broad agreement” that this should be performed with PCN. Patients with obstruction subsequent to pelvic malignancy and the pregnant patient are discussed.

Conclusion:

The authors hope that these results and recommendations will aid clinical decision-making and aid the development of local and regional PCN and RUS services.

Likelihood of retrograde double-J stenting according to ureteral obstructing pathology

OBJECTIVES

To evaluate the likelihood of retrograde double-J stenting in urgent ureteral drainage according to obstructing pathology.

MATERIALS AND METHODS

From July 2002 to January 2003, 43 consecutive patients with ureteral obstruction who needed urgent decompression were evaluated at our institution, where we performed a total of 47 procedures. Emergency was defined as ureteral obstruction associated with infection, obstructive acute renal failure, or refractory pain. Ureteral obstruction was defined as intrinsic and extrinsic based on etiology and evaluated by ultrasound. Patients submitted to previous double-J stenting were excluded. Failures in retrograde ureteral stenting were treated with percutaneous nephrostomy. Results were analyzed with Fisher's exact test and regression analysis.

RESULTS

Failure in retrograde ureteral stenting occurred in 9% (2/22) and 52% (13/25) of the attempts in patients with intrinsic and extrinsic obstruction respectively (p < 0.001). Failures in stenting extrinsic obstructions occurred due to lack of identification of the ureteral meatus in 77% and impossibility of catheter progression in 23% (p < 0.05). All attempts of retrograde catheter insertion failed in obstructions caused by prostate or bladder pathologies (6/6). Inability to identify the ureteral meatus was the cause of all failures.

CONCLUSION

Retrograde double-J stenting has a low probability of success in extrinsic ureteral obstruction caused by prostate or bladder disease. Such cases might be best managed with percutaneous nephrostomy.

Percutaneous Treatment of the Obstructive Uropathy

Purpose

to analyse the technical aspects, the patient's selection criteria, and some useful tactics to reduce the complications of percutaneous nephrostomy and of other interventional procedures to temporarily treat obstructive uropathy (OU), such as double J stent insertion, dilatation of the stricture using high-pressure balloon catheters, removal of renal or ureteral calculi, fistulas treatment.

Materials and Methods

a fluoroscopy table and an ultrasonographic guidance are key elements. Two techniques are employed, either the Seldinger type (wire-guided catheters) or the trocar needle type. Sole contraindication: uncorrectable severe coagulopathy. Most important risk factors are: dendritic calculus, non corrected high blood pressure, obesity, small size kidney, severe scoliosis.

Results

high technical success of the procedure in case of dilated collecting systems (98%); it is minor without dilatation (85%).

Conclusion

percutaneous nephrostomy is indicated in 87% of obstructive uropathy cases. It represents the basic technique allowing other interventional procedures to treat obstructive uropathy; it should be performed by most radiologists following an adequate training with technique and materials.

Combined antegrade and retrograde ureteral stenting: the rendezvous technique

Ureteral stenting is a routine procedure in endourology. To increase the success rate in difficult cases, it may be helpful to use the rendezvous technique, a combined antegrade and retrograde approach. We performed 16 urological rendezvous in 11 patients with ureteral strictures or urologic lesions. The combined approach was successful in all patients, without morbidity or mortality. In our experience the rendezvous technique increased the success rate of antegrade ureteral stenting from 78.6 to 88.09% (p > 0.05). This procedure is a valid option in case of failure of conventional ureteral stenting.

Prolonged ureteral stenting in obstruction after renal transplantation: long-term results

BACKGROUND

Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our long-term follow-up results concerning endourologic treatment of ureteral obstruction after renal transplantation.

METHODS

Between May 1997 and September 2000, 15 patients with renal transplant obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting.

RESULTS

Percutaneous nephrostomies were performed successfully in all 15 kidneys. In 13 patients, antegrade ureteral stenting was attempted, which was successful in 11 patients (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in all patients, 90% of whom had no recurrence. During follow-up (36 to 71 months; mean 51), urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed. Success was defined as a reduction in hydronephrosis. No major complications were observed.

CONCLUSIONS

Modern endourologic procedures have replaced open reconstructive surgery in most patients with ureteral obstruction after renal transplantation, because they may offer a definitive treatment with low morbidity.

Obstructive uropathy in the transplanted kidney: definitive management with percutaneous nephrostomy and prolonged ureteral stenting

BACKGROUND AND PURPOSE

Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our experience with percutaneous nephrostomy and antegrade ureteral stenting, which may offer a primary and definitive alternative to open surgery.

PATIENTS AND METHODS

Fifteen patients with renal allograft obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting.

RESULTS

Percutaneous nephrostomies were successfully performed in all 15 kidneys: In 13 patients, antegrade ureteral stenting was attempted, this being successful in 11 (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in eight patients, and six of them (75%) did not have recurrences. During follow-up, urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed, and success was confirmed by the decline of creatinine and reduction in hydronephrosis. No major complication was observed.

CONCLUSION

Percutaneous nephrostomy and ureteral stenting is a safe and effective treatment for renal allograft obstructive uropathy. Prolonged ureteral stenting may offer a definitive treatment with low morbidity.