Improved Split Renal Function after Percutaneous Nephrostomy in Young Adults with Severe Hydronephrosis Due to Ureteropelvic Junction Obstruction

Meta-analysis of perioperative outcomes and safety of percutaneous nephrostomy versus retrograde ureteral stenting in the treatment of acute obstructive upper urinary tract infection

Background

The debate regarding the optimal drainage method for acute obstructive upper urinary tract infection persists, focusing on the choice between percutaneous nephrostomy (PCN) and retrograde ureteral stenting (RUS).

Aims

This study aims to systematically examine the perioperative outcomes and safety associated with PCN and RUS in treating acute obstructive upper urinary tract infections.

Methods

A comprehensive investigation was conducted using the Medline, Embase, Web of Science, and Cochrane databases up to December 2022, following the guidelines of the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The utilized keywords included 'PCN', 'RUS', 'acute upper obstructive uropathy', and 'RCT'. Inclusion criteria encompassed studies providing accurate and analyzable data, which incorporated the total subject count, perioperative outcomes, and complication rates. The assessed perioperative outcomes included fluoroscopy time, normalization of temperature, normalization of serum creatinine, normalization of white blood cell (WBC) count, and operative time. Safety outcomes encompassed failure rate, intraoperative and postoperative hematuria, postoperative fever, postoperative pain, and postoperative nephrostomy tube or stent slippage rate. The study protocol was prospectively registered at PROSPERO (CRD42022352474).

Results

The meta-analysis encompassed 7 trials involving 727 patients, with 412 assigned to the PCN group and 315 to the RUS group. The outcome of the meta-analysis unveiled a reduced occurrence of postoperative hematuria in the PCN group [odds ratio (OR) = 0.54, 95% confidence interval (CI) 0.30-0.99, p = 0.04], along with a decreased frequency of insertion failure (OR = 0.42, 95% CI 0.21-0.81, p = 0.01). In addition, the RUS group exhibited a shorter fluoroscopy time than the PCN group (mean difference = 0.31, 95% CI 0.14-0.48, p = 0.0004).

Conclusion

Given the significant impact of hematuria and catheterization failure on postoperative quality of life, the preference for PCN appears more advantageous than RUS.

Demirtas Two-Step Treatment Model in Hypofunctional-Obstructed Kidneys: An Extended Series and Long-Term Prospective Results

Aim: This study aimed to present the short- and long-term results of Demirtas two-step treatment model in patients with obstructed-hydronephrotic kidneys functioning below 10%, and before deciding on nephrectomy, to evaluate whether this method can contribute to the accurate assessment.

Material and methods: This prospective study included patients with unilateral renal obstruction and renal parenchymal loss assessed by computed tomography and whose renal function was found to be below 10% in Tc-99m-dimercaptosuccinic acid. In the first step, percutaneous nephrostomy (PCN) was performed. Two weeks later, the second step was performed, in which patients were offered nephrectomy (if renal function was <10%) or etiology-based treatment (if renal function was ≥10%).

Results: Thirty-eight patients were included in the study, comprising 20 (52.6%) men and 18 (47.4%) women with a mean age of 51.3±16.8 years. Mean baseline renal function was 6.0%, which increased to 10.8% two weeks after PCN (p=0.001). Renal function increased to above 10% in 20 (52.6%) out of 38 patients. Of these, 17 patients underwent etiology-based treatment and baseline, two-week, and 12-month renal function levels were 7.0%, 17.5%, and 18.8%, respectively (p<0.001).

Conclusion: Demirtas two-step treatment model introduced in the present study can be recommended as a standard treatment modality in unilaterally obstructed kidneys functioning below 10% ability.

Short-term outcomes of pyeloplasty vs. nephrectomy in adult patients with ureteropelvic junction obstruction and differential renal function ≤15

OBJECTIVES

To compare symptom resolution and short-term renal function after pyeloplasty or nephrectomy in adults with ureteropelvic junction obstruction (UPJO) in poorly functioning renal units (PFRU).

METHODS

Retrospective analysis of adult patients with UPJO and differential renal function (DRF) ≤ 15% who underwent laparoscopic pyeloplasty or nephrectomy. Primary endpoints included symptom resolution and estimated glomerular filtration rate (eGFR) at 12 months. Surgical complications were compared between groups. A secondary analysis was performed comparing baseline and postoperative DRF to evaluate the PFRU recovery potential after pyeloplasty.

RESULTS

Sixty-three patients were included; 19 underwent pyeloplasty and 44 underwent nephrectomy. The mean age of the cohort was 39.5 ± 13.8 years. Nephrectomy was associated with significantly higher intra-operative blood loss (p = 0.02). Operative time and length of hospital stay were not significantly different between groups. There were three complications in the nephrectomy group, and none in the pyeloplasty group (p = 0.34). Symptom resolution rates were equivalent between groups (73% vs. 76%; p = 0.78). The eGFR variation was not statistically different after pyeloplasty or nephrectomy (+6.2 vs. +0.1 mL/min/1.73m², respectively; p = 0.18). Patients undergoing pyeloplasty had no significant change in the mean DRF (baseline 9.5 vs. 10%; p = 0.99).

CONCLUSION

Pyeloplasty can be considered for selected patients with UPJO in PFRU as an organ-sparing alternative to nephrectomy. Although there was no significant gain in mean DRF, pyeloplasty prevented further functional loss and relieved symptoms in most cases in the short-term with at least the same complication rates of nephrectomy.

Outcomes of ultrasound-guided percutaneous nephrolithotomy for the treatment of large stones within non-functioning atrophic kidneys

OBJECTIVES

To evaluate outcomes in patients who underwent total ultrasound-guided percutaneous nephrolithotomy for the management of large stones (>2 cm) within non-functioning atrophic kidneys, and to identify risk factors associated with postoperative persistence of urinary tract infection symptoms in such patients.

METHODS

Between December 2014 and May 2019, 56 patients with large stones within non-functioning atrophic kidneys were treated at Beijing Tsinghua Changgung Hospital, Beijing, China, with total ultrasound-guided percutaneous nephrolithotomy. Factors including age, sex, previous medical history, stone burden, stone composition, stone-free rate, complication rate and postoperative urinary tract infection symptoms were retrospectively evaluated. Uni- and multivariate analyses were carried out to identify risk factors that predict persistence of urinary tract infection symptoms after percutaneous nephrolithotomy in such patients.

RESULTS

The final stone-free rate after auxiliary treatments was 87.5%. The overall complication rate was 17.9%. After a median follow-up period of 12 months (range 6-40 months), three patients (5.4%) ultimately underwent nephrectomy. A total of 44 patients (78.6%) had no symptoms of urinary tract infection during follow up, whereas 63.6% of patients with diabetes continued to show persistent urinary tract infection symptoms at the latest follow up. Five patients (8.9%) showed improved total renal function, while most patients (83.9%) showed a stable estimated glomerular filtration rate. Diabetes was the only factor showing statistical significance in both univariate and multivariate analyses that predicted persistence of urinary tract infection symptoms after treatment with percutaneous nephrolithotomy.

CONCLUSIONS

Ultrasound-guided percutaneous nephrolithotomy is a safe and feasible procedure that can be carried out in patients with large stones within non-functioning atrophic kidneys. However, for such patients with diabetes, percutaneous nephrolithotomy is not recommended.

Does Diversion in Poorly Functioning Obstructed Kidneys in Adults Favors Reconstructive Surgeries Over Ablative Procedures? A Prospective Study

Objective In obstructed poorly functioning kidneys, management depends on the recovery potential of the kidney. Some kidneys have good recovery capability and diversion may unfold the real condition of the kidney. This study evaluated whether pre-operative drainage for six weeks results in improvement of renal function in unilateral obstructed poorly functioning kidney with split renal function (SRF) less than 20%. Methods This was a prospective interventional study conducted between March 2013 and December 2015. All patients between 15 and 65 years, with unilaterally obstructed kidney with SRF ≤20% underwent percutaneous nephrostomy (PCN) drainage for six weeks. Patients having post-drainage SRF of ≥15% and per day urine output from PCN > 400 ml were considered for the reconstructive procedure. Nephrectomy was performed in cases with SRF <15% after considering patient preferences. Results Twelve of 17 patients had improvement in SRF; four had no change while one had a decrease in SRF after drainage. The mean improvement in glomerular filtration rate (GFR) and SRF was 1.4 ml/min and 3%, respectively (P = 0.08). Three out of seven patients with SRF of ≥15% showed an improvement of 5% or more while none of the patients with SRF <15% had such an improvement. Eight patients had final SRF <15% and underwent nephrectomy. Factors such as pre-existing SRF, duration of symptoms, kidney size, transverse pelvic diameter, 24-hour urinary output, and etiology for obstruction were not significant in predicting functional improvement. Conclusion Diversion and decompression of poorly functioning kidneys do not result in a significant functional improvement in obstructed kidneys with SRF <15%.

Laparoscopic pyeloplasty as an alternative to nephrectomy in adults with poorly functioning kidneys due to ureteropelvic junction obstruction

OBJECTIVES

To evaluate outcomes of laparoscopic pyeloplasty (LP) in adults with poorly functioning kidney due to ureteropelvic junction obstruction (UPJO).

METHODS

A retrospective comparative analysis was performed between adult patients who underwent LP due to UPJO with differential renal function (DRF) ≤ 15% and DRF > 15%. LP success rate and complications were assessed. LP success was defined as symptoms improvement and DRF improvement or stabilization. DRF and estimated glomerular filtration rate (eGFR) were analyzed before and 12 months after surgery to evaluate renal function recovery. DRF was estimated using Tc-99 m DMSA renal scintigraphy.

RESULTS

Among 121 LP performed in the study period at our institution, 15 and 42 were included in the DRF ≤ 15% and DRF > 15% groups, respectively. At a median follow-up of 17.8 months, all patients with DRF ≤ 15% reported symptoms improvement. LP success rate was 86.7% and 90.5% (p = 0.65) for patients with DRF ≤ 15% and DRF > 15%, respectively. There were no complications in the DRF ≤ 15% group, while there were three complications recorded in the DRF > 15% group (Clavien 2 and 3b). In the DRF ≤ 15% group, mean pre-operative and post-operative DRF was 9.5% ± 3.6 and 10.5% ± 7.8 (p = 0.49), respectively. Median pre-operative and post-operative eGFR was 68.5 ml/min and 79.8 ml/min (p = 0.93), respectively. Two patients had DRF improvement after LP.

CONCLUSIONS

LP in adult patients with UPJO and poor function kidneys is an effective and safe procedure. DRF recovery is seen in a minority of the patients; however, LP is an alternative to nephrectomy.

Pelvic ureteric junction obstruction: Natural history, nephrological considerations and current evidence base for surgical management in poorer functioning kidneys

Pelvic ureteric junction obstruction (PUJO) can pose a management challenge to urologists. The natural history of the disease, particularly in adults is poorly understood and management decisions are largely based on historical, poor quality data. Additionally, many older patients may already have a degree of renal impairment secondary to systemic disease, further compounding the situation. The purpose of this paper is to detail the pathophysiology and natural history of PUJO, discuss the implications of chronic kidney disease in this population detailing the current evidence base for poorer functioning kidneys and describe the nephrological advantages of accurate renal function testing. There exists accurate methods to assess both glomerular filtration rate (GFR) and split function which could potentially provide both the urologist and patient with more relevant data on which to base their decisions when contemplating surgical intervention. The existing, low patient number case series currently published fail to address the relevance of overall GFR on the outcomes after pyeloplasty, no studies use single unit GFR and there is no clear consensus on what constitutes surgical success. PUJO is an area of benign upper tract disease that is in need of high-quality scientific studies to identify when intervention is necessary, long-term success of both surgery and conservative management in poorer functioning kidneys and clear guidelines for urologists.

Surgical treatment reduces blood pressure in children with unilateral congenital hydronephrosis

OBJECTIVE

Renal disorders can cause hypertension, but less is known about the influence of hydronephrosis on blood pressure. Hydronephrosis due to pelvo-ureteric junction obstruction (PUJO) is a fairly common condition (incidence in newborns of 0.5-1%). Although hypertensive effects of hydronephrosis have been suggested, this has not been substantiated by prospective studies in humans [1-3]. Experimental studies with PUJO have shown that animals with induced hydronephrosis develop salt-sensitive hypertension, which strongly correlate to the degree of obstruction [4-7]. Moreover, relief of the obstruction normalized blood pressure [8]. In this first prospective study our aim was to study the blood pressure pattern in pediatric patients with hydronephrosis before and after surgical correction of the ureteral obstruction. Specifically, we investigated if preoperative blood pressure is reduced after surgery and if split renal function and renographic excretion curves provide any prognostic information.

PATIENTS AND METHODS

Twelve patients with unilateral congenital hydronephrosis were included in this prospective study. Ambulatory blood pressure (24 h) was measured preoperatively and six months after surgery. Preoperative evaluations of bilateral renal function by Tc99m-MAG3 scintigraphy, and renography curves, classified according to O'Reilly, were also performed.

RESULTS

As shown in the summary figure, postoperative systolic (103 ± 2 mmHg) and diastolic (62 ± 2 mmHg) blood pressure were significantly lower than those obtained preoperatively (110 ± 4 and 69 ± 2 mmHg, respectively), whereas no changes in circadian variation or pulse pressure were observed. Renal functional share of the hydronephrotic kidney ranged from 11 to 55%. There was no correlation between the degree of renal function impairment and the preoperative excretory pattern, or between the preoperative excretory pattern and the blood pressure reduction postoperatively. However, preoperative MAG3 function of the affected kidney correlated with the magnitude of blood pressure change after surgery.

DISCUSSION

Correction of the obstruction lowered blood pressure, and the reduction in blood pressure appeared to correlate with the degree of renal functional impairment, but not with the excretory pattern. Thus, in the setting of hypertension, it appears that the functional share of the hydronephrotic kidney should be considered an indicator of the need for surgery, whereas the renography curve is less reliable. The strength of the present study is the prospective nature and that ambulatory blood pressure monitoring was used. Future longitudinal prolonged follow-up studies are warranted to confirm the present findings, and to understand if a real nephrogenic hypertension with potential necessity of treatment will develop.

CONCLUSION

This novel prospective study in patients with congenital hydronephrosis demonstrates a reduction in blood pressure following relief of the obstruction. Based on the present results, we propose that the blood pressure level should also be taken into account when deciding whether to correct hydronephrosis surgically or not.