Preoperative Differential Renal Function Research Articles

Risk and protective factors for secondary procedures after endoscopic dilatation of primary obstructive megaureters.

High-pressure balloon dilatation (HPBD) of the ureterovesical junction with double-J stenting is a minimally invasive alternative to ureteral reimplantation or cutaneous ureterostomy for first-line surgical treatment of primary obstructive megaureter (POM). The aim of our study was to identify the risk factors associated with the need for secondary procedures due to HPBD failure. Prospective data were collected from patients who underwent HPBD for POM between 2007 and 2021 at a single institution. The collected data included patient demographics, diagnostic modalities, surgical details, results, and follow-up. Multivariate logistic regression analysis was performed. Fifty-five ureters underwent HPBD for POM in 50 children, with a median age of 6.4months (IQR: 4.5-13.8). Nineteen patients (37.25%) underwent secondary ureteric reimplantation, with a median of 9.8months after primary HBPD (95% CI 6.2-9.9). The median follow-up was 29.4months (IQR: 17.4-71). Independent risk factors for redo-surgery in a multivariate logistic regression model were: progressive ureterohydronephrosis (OR = 7.8; 95% CI 0.77-78.6) and early removal of the double-J stent. A risk reduction of 7% (95% CI 2.2%-11.4%) was observed per extra-day of catheter maintenance. The optimal cut-off point is 55days, ROC curve area: 0.77 (95% CI 0.62-0.92). Gender, distal ureteral diameter, pelvis diameter, dilatation balloon diameter and preoperative differential renal function did not affect the need for reimplantation. The use of a double-J stent for at least 55days seems to avoid the need for a secondary procedure. Therefore, we recommend removing the double-J catheter at least 2months after the HBPD.

Outcomes of robot-assisted laparoscopic pyeloplasty among pediatric patients with complex renal anatomy: A retrospective comparative study

Robot-assisted laparoscopic pyeloplasty (RALP) has been increasingly utilized in the treatment of pediatric ureteropelvic junction obstruction (UPJO) with reported success rates of >95%. Complex renal anatomy can make some cases challenging to reconstruct. To evaluate outcomes of children undergoing RALP with aberrant renal anatomy and compare it to those with simple renal anatomy. An IRB approved prospective registry was queried to retrospectively identify all patients who underwent robotic pyeloplasty at our institution from 2012 to 2022. Patients undergoing re-do pyeloplasty were excluded. Complex anatomy was defined as horseshoe kidney, ectopic/pelvic kidney, duplex collecting system, fully bifid renal pelvis and severe malrotation (≥180°). A comparative analysis of baseline demographics, pre-operative clinical/radiological characteristics, intra and post-operative details, and long-term success was performed between those patients with complex anatomy and those without. Of 405 total robotic pyeloplasty's, 375 patients (378 total pyeloplasty; 353 simple, 22 complex) met inclusion criteria. 27 re-do were excluded from analysis. The complex pyeloplasty cohort included 9 horseshoe kidneys, 8 duplex collecting systems, 3 ectopic/pelvic kidneys and 2 kidneys with severe malrotation. There was no difference in age (58 vs 31 months; p=0.38), procedure time (203 vs 207min; p=0.06), length of stay (1.4 vs 1.3 days; p=0.99), or success (91.6% vs 100%; p=0.24) between the simple and complex groups. Etiology of obstruction differed significantly between groups - high insertion was more common (3.9% vs 18.2%, p=0.02) and intrinsic narrowing was less common (60.1% vs 36.4%, p=0.04) in patients with complex anatomy. A multivariate logistic regression was adjusted for age, gender, etiology of obstruction, preoperative differential renal function and post-operative complications and found no difference in success between complex and simple RALP. The findings showed no significant differences in age, procedure time, length of hospital stay, or success rates between the two groups. Specifically, the success rates were 91.6% for the complex group and 100% for the simple group (p=0.24), indicating comparable efficacy. However, the etiology of obstruction varied significantly, with high ureteral insertion more common in the complex anatomy group (18.2% vs. 3.9%, p=0.02) and intrinsic narrowing less common (36.4% vs. 60.1%, p=0.04). Despite these differences, multivariate logistic regression, adjusted for confounders, confirmed no difference in success rates between the groups. RALP is a safe and efficacious approach in patients with complex anatomy with success rates comparable to index patients. High ureteral insertion does appear to be more common in patients with complex anatomy undergoing pyeloplasty.

Renal Histopathological Changes in Children With Congenital Ureteropelvic Junction Obstruction

Renal histologic changes in congenital ureteropelvic junction obstruction (UPJO), although well documented, are sparsely studied in children. This study aims to establish a histological grading depending on the glomerular and tubulo-interstitial changes in hydronephrotic kidneys and determine correlation with age at surgery and impact on function post-pyeloplasty. A renal cortical wedge biopsy was obtained after pyeloplasty and histological changes were graded from 1 to 4. A total of 47 viable biopsies from 57 children showed grade 1 changes in 10, grade 2 in 7, grade 3 in 27, and grade 4 in 3. Age at surgery, histological grade, and changes in differential renal function (DRF) were statistically analyzed. Younger age, near normal histology, and those with changes in 1 domain had preserved DRF pre-operatively. Renal histology and overall grade showed positive correlation with pre-operative DRF. However, no statistically significant association was noted with age at surgery or change in post-operative DRF.

Feasibility and Effectiveness of Repeat Laparoscopic Pyeloplasty for Recurrent Ureteropelvic Junction Obstruction in Pediatric Patients.

Objective: To assess the outcomes of redo laparoscopic pyeloplasty (RLP) in pediatric patients with recurrent ureteropelvic junction obstruction (UPJO) in contrast to redo open pyeloplasty (ROP). In addition, evaluate the feasibility and efficacy of RLP as a treatment modality for recurrent UPJO in children. Materials and Methods: The data of 44 patients from March 2012 to March 2022, who underwent redo pyeloplasty, were retrospectively reviewed. In Group RLP, the children underwent RLP, whereas ROP was attempted in Group ROP. Demographics, clinical manifestations, surgical duration, hospitalization duration, complication rates, and treatment success were examined within the respective groups. Moreover, preoperative and postoperative measurements of anterior-posterior diameter of the renal pelvis (APD), preoperative assessment of differential renal function (DRF), and the percentage of improvement in DRF (PI-DRF) were subject to analysis. Results: The study included 28 patients who underwent RLP (Group RLP), and 16 patients who underwent ROP (Group ROP). In all cases, the Anderson-Hynes technique was employed. There was no significant difference between the two groups regarding age, body mass index, gender distribution, affected side, preoperative APD, postoperative APD, and preoperative DRF. In comparison to Group ROP, Group RLP exhibited a shorter hospitalization duration, a longer surgical procedure duration, and a higher percentage improvement in PI-DRF. The median follow-up period for Group RLP was 25 months, whereas it was 25.5 months for Group ROP. Notably, the success rates were similar between the two groups, with a success rate of 89.2% in RLP and 87.5% in ROP (p = 0.634). Conclusion: RLP has a comparable success rate to ROP and is a safe, effective, and feasible procedure for the treatment of failed pyeloplasty in children.

Can We Predict Renal Function Recovery After Pyeloplasty in Pediatrics with Ureteropelvic Junction Obstruction? A Systematic Review.

Chronic unilateral renal obstruction, primarily caused by ureteropelvic junction obstruction (UPJO), poses challenges in determining the optimal timing for corrective surgery. The goal is to preserve renal function and alleviate symptoms, but there is no definitive diagnostic test to reliably predict the outcomes of surgery. This systematic review aimed to identify predictors for renal function recovery after pyeloplasty in order to guide effective treatment options. We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A literature search was performed on PubMed, Embase, and Scopus using keywords related to renal function, pyeloplasty, and predictors. The search was conducted on March 10, 2022. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Out of 344 potentially relevant articles, 11 met the eligibility criteria for this study. These included 6 retrospective and 5 prospective studies, with a total of 925 participants. Most studies evaluated renal function using differential renal function (DRF). The overall quality of the included studies was considered average. The findings indicated that age at the time of surgery and gender did not significantly influence functional recovery after pyeloplasty. However, preoperative DRF consistently emerged as a critical predictor. Preoperative DRF can serve as the most common predictors used for renal function recovery following pyeloplasty. These findings contribute to understanding effective treatment options for chronic unilateral renal obstruction. However, further research for each predictor is needed to validate these predictors and their clinical utility. Cite this article as: Siregar S, Mustafa A, Steven S. Can we predict renal function recovery after pyeloplasty in pediatrics with ureteropelvic junction obstruction? A systematic review. Urol Res Pract. Published online March 31, 2024. DOI:10.5152/tud.2024.23220.

Ureteropelvic junction obstruction with polyps in children: clinical manifestations and supranormal preoperative differential renal function.

To describe and analyze the clinical manifestation and pre-DRF of UPJO children with polyps and explore the possible influencing factors of supranormal pre-DRF. All patients undergoing primary Anderson-Hynes pyeloplasty for UPJO due to polyp were retrospectively reviewed. Patients' characteristics, parameters of ultrasound and dynamic renograms (DR) were recorded in elaborate. Pre-DRF in groups of different age, weight, gender, pain, grade of hydronephrosis, anterio-posterior pelvic diameter (APD), length of kidney and postoperative ultrasonic parameters were compared. A total of 18 UPJO children with polyps were included. Five (27.78%) patients had SFU III grade of hydronephrosis. Seven (38.89%) patients were supranormal pre-DRF. All patients had pre-DRF > 40%. Drainage curve was delayed excretion in 12 (66.67%) patients and T1/2 < 20min was in 4 (22.22%) patients. Among the 16 patients who underwent preoperative IVP examination, 15 (93.75%) patients had concentration of intrarenal pelvis contrast agent within 10min. No significant difference in post-APD reduction rate and post-minPT increased was found between supranormal pre-DRF and non-supranormal pre-DRF groups. The supranormal pre-DRF was more likely to occur in young and low-weight children. The preoperative renal function of UPJO patients with polyps was well preserved, and 38.89% of them had supranormal pre-DRF. Patients with supranormal pre-DRF can be managed with the same strategies as those with normal renal function.

Risk factors for adverse outcomes after pediatric pyeloplasty: A retrospective cohort study.

To identify the risk factors for adverse outcomes after pediatric pyeloplasty. We conducted a retrospective review of all children under the age of 14 years who underwent primary pyeloplasty for unilateral ureteropelvic junction (UPJ) obstruction at a single teaching hospital in Tunisia between January 1, 2013, and December 31, 2022. A total of 103 patients were included. Median age of patients at surgery was 27 months (interquartile range [IQR], 13-44). On ultrasound, median renal pelvic anteroposterior diameter was 3.2 cm (IQR, 2.3-4), and the median renal cortex thickness (RCT) was 2.5 mm (IQR, 2-3.5). Median differential renal function (DRF) on preoperative radionuclide renal scan was 40% (IQR, 30-46). Postoperative adverse outcomes occurred in 28 patients (27.2%). These included 19 cases of urinary tract infections (UTIs), 11 cases of UPJ restenosis, four cases of UPJ leakage, two cases of urinoma, and two cases of diversion-related complications. Multivariate logistic regression analysis revealed two factors significantly and independently related to postoperative negative outcomes: RCT <3 mm and DRF > 50%. Our study demonstrated that preoperative RCT on ultrasound of less than 3 mm and preoperative DRF on radionuclide renal scan of more than 50% were independent risk factors for adverse outcomes following pediatric pyeloplasty. These factors could be of interest in identifying, early on, patients who will develop postoperative negative outcomes, giving them more attention and support, and explaining the prognosis to the patient and family.

LAPAROSCOPIC TRANSPERITONEAL PYELOPLASTY FORURETEROPELVIC JUNCTION OBSTRUCTION IN PAEDIATRICPOPULATIONGROUP

Background: The ureteropelvic junction obstruction (UPJO) is one of the most prevalent genitourinaryabnormalities in children. PUJO is considered as the most common cause of congenital hydronephrosis.Pyeloplasty is the main treatment method for patients with UPJO [5]. An ideal treatment should have thehighest success rate and be minimally invasive. There are many techniques for PUJO repair, but theDismembered AndersonHynes pyeloplasty remains thegoldstandardfor surgicalreconstruction[8].LaparoscopicAnderson-Hynes pyeloplasty has becomethegoldstandardinmanypediatriccenters Objectives: To assess the safety and efficacy of laparoscopic transperitoneal pyeloplasty in children withPUJ obstruction. Methods: The study included 30 consecutive cases of congenital unilateral PUJO with SRF &lt;40% managedduring the 24-month period from November 2020 to November 2022. All the patients were properlyevaluated before proceeding for procedure. Results: In our study the mean age of patients was 6.4 years. Most of the children affected were males(76.7%) andinvolvement of left pelvi-ureteric junction. The commonest cause of pelvi-ureteric junctionobstruction was an abnormal proximal segment (53.3%) followed by crossing vessel (20%).Thepre-opAPPD on ultrasonography was in range from 21mm to 50mm, with a mean pre op APPD of 36.26mm.Most of the patients (83%) had a pre-operative differential renal function in the range of 31-40%(34.8%).Mean operative time was 99.06mins. Mean post op APPD was 27.38mmand DRF was 40.72%. 96% ofthe patients had an indwelling catheter in situ for a period of less than one week. Out of total 30 patientsanastomoticdrainwaskeptfor6daysin28patients(93.34%).Meanhospitalstayindays was7.53days. Conclusion:Laparoscopictransperitonealpyeloplastyisasafeandeffective,minimallyinvasiveprocedure in pediatric patients, characterized by good surgical efficiency, reduced complications, fasterrecoveryand satisfactory followup results.

Outcome of Renal Function after Laparoscopic Pyeloplasty in Children with High-Grade Hydronephrosis

Introduction: This study aimed to analyze the changes in differential renal function (DRF) after laparoscopic pyeloplasty in children with high-grade hydronephrosis and factors influencing DRF improvement. Methods: We reviewed the clinical data of unilateral ureteropelvic junction obstruction (UPJO) patients with SFU grade IV who underwent laparoscopic pyeloplasty between February 2018 and October 2020. The patients were divided into two groups: DRF improvement ≥5% (group 1) and DRF improvement <5% (group 2). Preoperative, operative, and postoperative parameters were included in the statistical analysis in both groups. Results: A total of 29 patients with a median age of 6 months were included. The preoperative DRF in group 1 was significantly lower than that in group 2 (36.97 ± 8.47% vs. 45.19 ± 5.22%, p = 0.004). Logistic regression and receiver operating characteristic analysis showed the preoperative DRF was the predictor for renal function improvement after pyeloplasty (p = 0.021) and had a significant predictive value (p = 0.004). Conclusion: Nearly half of the patients with high-grade UPJO had improved renal function at 1 year follow-up after laparoscopic pyeloplasty. Preoperative DRF was a predictor of renal function improvement, and postoperative functional recovery was superior in children with lower preoperative DRF.

Clues for the early loss of renal function in congenital hydronephrosis: Analysis of renal pelvis collagen ratio, diuresis renography and upper urinary tract morphology

Diagnosing real urinary obstruction and surgical decision making for the operative correction of urinary obstruction, are still problematic in congenital hydronephrosis (CH). Compliance of the renal pelvis is one of the important defense mechanisms of renal parenchyma against urinary obstruction. We observed early loss of function in some cases of CH with low and moderate anteroposterior diameter of the renal pelvis (APDRP). To evaluate structural properties of the renal pelvic tissue of patients with CH and the relation of these structural properties with renal function and Anteroposterior diameter of the renal pelvis. Ureteropelvic junction (UPJ) excised during UPJ obstruction operations from 2013 to 2019 were evaluated histopathologically. The patients were divided into the two groups according to initial renal function, i.e. group with initial preoperative differential renal function (DRF) less than 35% and group with initial DRF greater than 35%. The percentage of collagen to whole tissue area were analyzed using image processing program. The relationship between DRF and tissue collagen ratio, SFU and APDRP was evaluated. There were 5 patients in the DRF <35% group and 16 patients in the DRF >35% group. However, APDRP's of the DRF <35% group were also significantly lower than the DRF >35% group. The collagen distribution in the muscle layer was more prominent in the DRF <35% group. Proportionally, percentage of collagen stained surface was significantly higher in DRF <35% group. There are numerous histopathological studies evaluating the cause of UPJ obstruction. Besides these studies that are oriented to etiology, there are many studies comparing the histopathological changes at UPJ with surgical outcome and prognosis. In the present study, we found that renal pelvis collagen ratio was significantly increased in patients with lower APDRP and with severe renal function loss. This increase in the collagen content in the renal pelvis have been shown to affect the compliance negatively and decrease APDRP, which leads to a faster loss of renal function. Thus, pelvic structural changes accompanying UPJ obstruction may aggravate urinary obstructive process. Increased renal pelvis collagen ratio negatively affects the expansion of the renal pelvis, which is one of the protective mechanisms of the renal parenchyma, and may be one of the triggering mechanisms of early loss of renal function.

Improvement of Renal Function after Pyeloplasty Determined by 99mTc DTPA Renogram

Objective: To evaluate the improvement of renal function after pyeloplasty measured by 99mTc-DTPA renography. Materials and Methods: This hospital based quasi experimental study was done in the department of urology, National Institute of Kidney Diseases and Urology (NIKDU) and Bangladesh Institute of Research and Rehabilitation for Diabetes, Endocrine and Metabolic Disorders (BIRDEM) from July 2014 to December 2020. Sixty patients were included in this study who underwent Anderson-Hynes (A-H) dismembered pyeloplasty for pelviureteric junction (PUJ) obstruction. All patients were evaluated with diuretic 99mTc- DTPA renogoam before and at 3 and 6 months after operation. Improvement of renal function was evaluated by comparing preoperative and postoperative differential renal function (DRF) and glomerular filtration rate (GFR). Results: Sixty patients with unilateral hydronephrosis due to PUJ obstruction were included in this study. Of these patients 34 male and 26 female with mean age of 15.6 years (ranged from 3 – 38 years). Out of 60 patients, 56.7% had left sided hydronephrosis and 43.3% had right sided hydronephrosis. Diuretic renography was done using 99mTc- DTPA in all patients preoperatively and at 3 and 6 months postoperatively. Preoperative mean DRF and GFR were compared with post-operative findings. The mean preoperative DRF in the study was 16.72 ± 8.35% at baseline which increased to 26.03 ± 7.08% at the end of 3rd month and 28.15 ± 5.84% at the end of 6th month. The mean preoperative GFR was 14.29 ± 6.73 ml/min/1.73 m2 at baseline which increased to 24.13 ± 5.31ml/min/ 1.73 m2 at the end of 3rd month and 27.38 ± 4.78 ml/min/1.73 m2 at the end of 6th month. Conclusion: The result demonstrates that, after pyeloplasty renal function improves. Highest recovery of renal function occurs in children and patients with poor pre-operative DRF and GFR. Bangladesh J. Urol. 2021; 24(2): 155-160

Factors predicting improvement of differential renal function after pyeloplasty in children of ureteropelvic junction obstruction

To evaluate differential renal function (DRF) in unilateral ureteropelvic junction obstruction (UPJO) patients under 18 years old after pyeloplasty and to identify factors predicting postoperative improvement. A total of 95 patients with unilateral UPJO treated by pyeloplasty between March 2019 to March 2020 were prospective enrolled. All patients had preoperative dynamic renal scintigraphy and were required to review after surgery 6 months. We defined DRF improvement as postoperative DRF increased ≥5% (If preoperative DRF less than 55%) or postoperative DRF reduced ≥5% and reached a normal range (45-55%) (preoperative DRF more than 55%) with drainage improvement. Drainage improvement indications were defined as a resolution of symptoms; decrease in hydronephrosis without requiring additional procedures and T1/2＜20min in dynamic renal scintigraphy. All parameters were statistically compared. In the study, 28 (29.5%) patients showed improvement in postoperative DRF, and 67 (70.5%) patients maintained stable postoperative DRF. Gender, age, baseline DRF, anteroposterior pelvic diameters (APD), minimum and maximum renal parenchymal thickness (PT), and anterior-posterior diameter/maximum renal parenchymal thickness (APD/PT) were correlated with postoperative DRF improvement in univariable analysis. In the multivariable analyses, maximum PT and APD/PT were predictors of improvement in postoperative DRF. In our study, the maximum PT was associated with the improvement of renal function in patients with UPJO, and when the thickest part of the renal parenchyma was measured, APD/PT can predict the improvement of renal function. We infer that the compression of the thickest part of the renal parenchyma may be the reason for the impaired renal function in some patients, and when the obstruction was relieved, the compressed parenchyma function can be significantly improved. Postoperative DRF of UPJO patients can be effectively improved and preserved through pyeloplasty. Maximum PT and APD/PT can predict improvement of renal function in patients with UPJO after pyeloplasty.

Evaluation of renal function after pyeloplasty determined by 99mTc DTPA renogram

Background: Hydronephrosis (HDN) due to pelviureteric junction (PUJ) obstruction is a common congenital anomaly of urinary tract which is generally treated by pyeloplasty. But the extent of functional recovery is still debated. Considering the existing controversies, this study was designed to evaluate the changes of renal function after pyeloplasty measured by 99mTc-DTPA renography.&#x0D; Methods: This study was done in the department of urology, National Institute of Kidney Diseases and Urology (NIKDU) and Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) General Hospital from July 2014 to December 2020. Sixty patients were included in this study and underwent Anderson-Hynes (A-H) dismembered pyeloplasty for PUJ obstruction. All patients were evaluated with diuretic 99mTc-DTPA renogoam before and at 3 and 6 months after pyeloplasty. Improvement of renal function was evaluated by comparing preoperative and postoperative differential renal function (DRF) and glomerular filtration rate (GFR).&#x0D; Results: Sixty patients (34 male and 26 female) with unilateral HDN due to PUJ obstruction were included in this study with mean age of 15.6 years (ranged from 3 – 38 years). Out of 60 patients, 56.7% had left sided HDN and 43.3% had right sided HDN. The mean preoperative DRF was 16.72 ± 8.35% at baseline which increased to 26.03 ± 7.08% at the end of 3rd month and 28.15 ± 5.84% at the end of 6th month. The mean preoperative GFR was 14.29 ± 6.73 ml/min/1.73 m2 at baseline which increased to 24.13 ± 5.31ml/min/1.73 m2 at the end of 3rd month and 27.38 ± 4.78 ml/min/1.73 m2 at the end of 6th month.&#x0D; Conclusion: The result demonstrates that, after pyeloplasty renal function improves. Highest recovery of renal function noted in patients with poor pre-operative DRF and GFR.&#x0D; BIRDEM Med J 2022; 12(2): 142-146

Erişkin Üreteropelvik Bileşke Darlığı Hastalarında Piyeloplastinin Başarısı: Retrospektif Klinik Çalışma

Objective: Ureteropelvic junction obstruction (UPJO) is a disease often diagnosed in childhood, but it can rarely be detected in adults. Dismembered pyeloplasty is the gold standard treatment method. In this study, we evaluated the success of pyeloplasty in adult patients with UPJO. Material and Methods: We retrospectively reviewed the data of the adult patients who underwent pyeloplasty between January 2012 and July 2021. Preoperative and postoperative differential renal function (DRF), the time required for the clearance of half of the radioisotope from the renal pelvis (T1/2), presence of symptoms, degree of hydronephrosis, anteroposterior (AP) diameter of the renal pelvis, and parenchymal thickness were compared. Results: A total of 30 patients with a mean age of 32.43±7.18 were included in the study. No statistically significant difference was detected between preoperative and postoperative mean DRF (37.6±12.08 and 38±11.35, respectively) (p=0.775). In 19 (63.33%) patients DRF remained unchanged. In 7 (23.33%) patients DRF was improved, and in 4 (13.34%) patients DRF deteriorated. The mean AP diameter and grade of hydronephrosis were significantly improved after pyeloplasty. The ratio of patients with a T1/2>20 minutes significantly decreased from 83.33% to 26.67% (p=0.001). Before the operation 26 (86.67%) patients were symptomatic. After the operation only 8 (26.67%) patients were symptomatic. This change was statistically significant (p=0.001). Conclusion: There were significant improvements in T1/2, AP diameter of the renal pelvis, and the degree of hydronephrosis. Renal function was preserved after the surgery. Also, pyeloplasty was effective in pain relief and should be recommended to adults with UPJO.

Renal autotransplant for major ureteric loss: Results from median 11 years of follow-up.

Renal autotransplant (RA) is an underutilized procedure to treat major ureteric loss. Studies on long-term outcomes and follow-up after RA are scarce. This study aimed to report the long-term outcomes and follow-up after RA. We identified 9 patients, from 2007 to 2019, who underwent RA after major ureteric loss (where direct restoration of continuity was not possible). We collected data regarding the etiology of ureteric loss, preoperative differential renal function, method of nephrectomy (laparoscopic or open), method of anastomosing the residual ureter/pelvis to the bladder, postoperative complications, duration of hospital stay, and renal function and drainage postoperatively and until the last follow-up. Changes in renal function and/or any obstruction to urinary drainage of the ipsilateral kidney postoperatively or during follow-up were measured. The Wilcoxon matched-pairs signed-rank test was used to compare the mean creatinine values preoperatively, postoperatively, and at last follow-up (p<0.05 was considered statistically significant). All the patients had uneventful intraoperative and postoperative periods. The mean hospital stay was 6.4 (5-8) days. The median follow-up was 132 (46-156) months. The mean preoperative serum creatinine level was 1.0 (0.7-1.7) mg/dL. The mean creatinine value postoperatively and at last follow-up had no significant difference with preoperative value (p=0.96 and 0.75, respectively). The postoperative diethylene triamine pentaacetic acid scan demonstrated good perfusion and drainage. There was no deterioration of renal function or drainage during the follow-up. RA is an excellent modality to treat major ureteric loss. It preserves renal function and avoids the problems related to bowel interposition and the need for long-term follow-up.

Does preoperative function affect the outcome following pyeloplasty in poorly functioning kidneys among pediatric population?

Aim:To determine the efficacy and outcome of pyeloplasty in poorly functioning kidneys in the pediatric population and whether pyeloplasty could be offered as an upfront procedure in such patient population, instead of nephrectomy.Materials and Methods:A retrospective data analysis of 83 patients who underwent pyeloplasty in poorly functioning kidneys from 2010 to 2015 was performed. Success was defined based on improvement in symptoms, stable or improved function, and better drainage on post-operative Tc-99m Diethylene Triamine Pentaacetic acid scan instead of DTPA scan renography done after 3 months and yearly thereafter.Results:Eighty-three patients with a mean age of 6.8 ± 2.88 years with poor function on isotope renogram (<30%) were included in the study. Three patients were excluded in view of postoperative outflow obstruction. Out of the remaining 80 patients, 56 were male and 24 were female. They were divided into two groups based on preoperative differential renal function (DRF), Group I (n = 26) having preoperative DRF of <10% and Group II (n = 54) having preoperative DRF of 10%–30%. All patients underwent laparoscopic dismembered pyeloplasty with ureteral stenting. The mean DRF improved from 7.58 ± 2.39 to 29.71 ± 5.16 postoperatively in Group I. However, in Group II, DRF improved from 20.81 ± 5.68 to 37.25 ± 7.11 postoperatively. At a follow-up of 24 months, the overall success rate was 98%.Conclusion:Pyeloplasty gives good intermediate-term results even in extremely poorly functioning kidneys and an upfront pyeloplasty instead of nephrectomy should be offered to all pediatric patients irrespective of preoperative function.

Pyeloplasty is a safe and effective surgical approach for low functioning kidneys with ureteropelvic junction obstruction

Indications for treatment of ureteropelvic junction obstruction (UPJO) include symptomatic obstruction, urinary tract infections, presence of an obstructive pattern on functional renal scan and/or worsening differential renal function (DRF). This paper aims to determine the relationship between preoperative DRF and surgical outcomes after pyeloplasty. We hypothesized that low preoperative DRF is not an independent predictor of pyeloplasty failure. A retrospective chart review was performed to identify all patients undergoing pyeloplasty for UPJO between 2008 and 2019. Patients were included only if they had at least one preoperative functional scan and a minimum of one renal ultrasound post-operatively. Patients were divided into three groups based on DRF for analysis: Group 1- 0-10%, Group 2 - >10-≤20%, Group 3 - >20%. Baseline, intraoperative and postoperative characteristics, including success and complications were compared. Additional sensitivity analyses were performed comparing patients with ≤20%, and >20% function, ≤30%, and >30% function as well as an analysis of patients undergoing only minimally invasive reconstruction. Three hundred and sixty-four patients met inclusion criteria. We identified 8 patients in Group 1, 24 patients in Group 2 and 332 patients in Group 3. Mean procedure time was longest for the ≤10% function group (237.9 vs 206.4 vs 189.1; p=0.01). We found no difference in 30-day post-operative complications, overall success rate or the need for additional procedures among the three groups. For patients in Group 1, we noted variation in the post-procedure DRF with a range of -2.8 to +47% change. In this group, none of patients with low DRF underwent nephrectomy. Multivariate logistic regression did not identify renal function as a predictor of operative success OR 1.00 (95% CI: 0.97-1.03) (p-value: 0.88). The results of the present study suggest that low DRF alone is not associated with worse outcomes and shows no difference in the failure rate. The incidence and type of complications were not increased for the lower functioning groups. The main limitation of this study would be its retrospective nature and single-institution experience. Furthermore, post-operative functional studies were not available for all patients, limiting the ability to draw conclusions on the change in DRF after surgery. In a large cohort, preoperative DRF was not predictive of pyeloplasty success rate. DRF ≤10% was not associated with higher incidence of complications or failure rate. The DRF alone should not dictate the management options available for patients with UPJO.

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

To evaluate outcomes of laparoscopic pyeloplasty (LP) in adults with poorly functioning kidney due to ureteropelvic junction obstruction (UPJO). 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 12months after surgery to evaluate renal function recovery. DRF was estimated using Tc-99m DMSA renal scintigraphy. 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 17.8months, 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 68.5ml/min and 79.8ml/min (p = 0.93), respectively. Two patients had DRF improvement after LP. 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.

The clinical manifestations of intermittent hydronephrosis and their relationship with renal function in pediatric patients

Most patients with intermittent hydronephrosis have preserved differential renal function (DRF), while others already have impaired DRF at diagnosis. We summarized the clinical manifestations of intermittent hydronephrosis to elucidate what may be related to DRF loss. We retrospectively reviewed patients presenting to our department with unilateral Dietl's Crisis between January 2014 and December 2017. Clinical characteristics were collected, including age of first onset, time of onset, duration of the longest single episodes and whether the patient had prenatally detected hydronephrosis. Ultrasonographic (US) parameters included anteroposterior diameter (APD) during the symptomatic and asymptomatic period. Dynamic renograms (DR) were reviewed to obtain preoperative DRF. A total of 150 patients met the selective criteria. Of the 128 patients whose mother had regular obstetric ultrasounds during pregnancy, 50 (39.06%) had prenatally detected pelvic dilation. The mean age of the first attack was earlier in the prenatally detected hydronephrosis group than in the postnatally detected group (4.58 vs 5.87, p=0.002). The mean preoperative DRF was 41.03% in all of the patients. The patients whose DRFs were below 40% had longer durations of single attacks than those over 40%. The former group also had larger APD during the symptomatic periods than the latter group. The risk of DRF < 40% was higher in the patients whose APD at attack was greater than 35mm (OR=5.111, χ2=12.899, p<0.001). The attack times, waiting time before the surgery and age of the first onset had no association with preoperative DRF. Our study first found that in patients with Dietl's Crisis, the APD during the symptomatic periods and the longest duration of the attack were associated with DRF loss. But the retrospective nature of our study limited us to understand the relationship between DRF and total duration of all attacks. This study revealed that children with prenatal hydronephrosis could develop Dietl's Crisis at early ages. A longer duration of attack and larger APD during the attack were associated with impaired DRF.

Changes in differential renal function after pyeloplasty in infants and children

Ureteropelvic junction obstruction (UPJO) is one of the most common causes of hydronephrosis in pediatric populations. Many need surgical intervention. The aim of surgery is preserving renal function and reducing symptoms such as urinary tract infections and pain. The objectives were to evaluate differential renal function (DRF) in infants and children after surgery for UPJO and to identify factors predicting postoperative improvement. The difference in outcomes between patients with antenatal hydronephrosis and those diagnosed later was evaluated. A total of 85 children (63 boys and 22 girls) aged 0-16 years, treated for UPJO with dismembered pyeloplasty, were followed up as per a structured protocol including ultrasounds and renal scans (MAG-3) pre-operatively and three and 18 months postoperatively. Five children with bilateral or single kidney UPJO were excluded. Patient records were retrospectively reviewed, and the patients were grouped as per prenatal (group 1, n=23) or postnatal (group 2, n=57) diagnosis. Univariable and multivariable logistic regression analyses searching for factors predicting >5% postoperative improvement in DRF on the obstructed side were performed. Factors included in analyses were age at diagnosis and surgery, sex, type of presentation, cause of obstruction, estimated glomerular filtration rate, pre-operative DRF, anteroposterior diameter (APD), APD/renal parenchymal thickness, and grade of hydronephrosis as per the Onen alternative grading system (grade 1-4). Pre-operative DRF on the obstructed side was a mean of 42% (standard deviation, 12), with no difference between the groups. The median age at surgery was 0.9 (0.2-10) and 8.1 (0.6-16) years in groups 1 and 2, respectively (P<0.001). The majority had unchanged DRF 18 months postoperatively, 19 (27%) patients improved by >5%, and one deteriorated. The proportion of patients with improved DRF was higher in group 1 (n=10; 45%, P=0.026). Anteroposterior diameter, APD/parenchymal thickness, pre-operative DRF, and antenatal diagnosis were predictors in the univariable analyses, and high APD (odds ratio [OR] = 1.1, P=0.0023), antenatal diagnosis (OR = 0.23, P=0.048), and low pre-operative DRF (OR = 0.90, P=0.0045) built the best model of independent factors predicting improvement in DRF in multivariable analyses (Summary Figure). The limitation of the study is that it is retrospective, but it has the advantage of auniform follow-up protocol, including patients from a five-year period, with few lost to follow-up. The results can be of interest in evaluating factors of importance for predicting recovery of function in obstructive uropathies in children. The majority of children had preserved or improved function after surgery for UPJO. Those with an antenatal diagnosis displayed a greater ability to catch up in DRF, and high APD, antenatal diagnosis, and low pre-operative DRF were independent predictive factors of an improvement in renal function after pyeloplasty.