Differences between intrinsic and extrinsic ureteropelvic junction obstruction related to crossing vessels: histology and functional analyses

Matrix Metalloproteinases in Ureteropelvic Junction Obstruction: Their Role in Pathogenesis and Their Use as Clinical Markers

The obstruction of the urinary tract is responsible for obstructive nephropathy (ON), also known as uropathy, which may then evolve in a renal parenchymal disease (hydronephrosis). Regarding the etiology of ON, it has been linked to the perturbation of processes occurring during the urinary tract development such as morphogenesis, maturation, and growth. Despite the research carried out in recent years, there is still a pressing need to elucidate the molecular processes underlying the disease. This may then result in the definition of novel biomarkers that can help in patient stratification and the monitoring of therapeutic choices. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with key roles in extracellular matrix remodeling due to their wide cleavage specificity and ability to modulate the bioavailability of growth factors. Despite the known changes in the local tissue microenvironment at the site of the urinary tract obstruction, the role of MMPs in ureteropelvic junction obstruction (UPJO) and, therefore, in the pathogenesis of renal damage in ON is not well-documented. In this review, we underline the possible roles of MMPs both in the pathogenesis of UPJO and in the progression of related hydronephrosis. The potential use of MMPs as biomarkers detectable in bodily fluids (such as the patient's urine) is also discussed.

The etiology of congenital obstructive uropathy: developmental and genetic perspectives

Congenital obstructive uropathy (COU) encompasses a heterogeneous group of anomalies arising during critical stages of fetal development, which are characterized by functional or structural obstruction of the urinary tract. This obstruction hampers normal urine flow, and the resulting urinary pressure build-up can damage the developing kidneys and bladder. COU pathogenesis is complex and its clinical outcomes are highly variable, ranging from asymptomatic ultrasonographic abnormalities to end-stage kidney disease. This review examines the developmental and genetic mechanisms underlying COU and the associated organ damage, with a focus on intrinsic, isolated forms. Although genetic studies have improved our understanding of the molecular pathways involved in urinary tract maldevelopment, most patients lack a genetic diagnosis. Hence, multiple etiologic factors appear at play, including (epi)genetic and environmental. Closing gaps in our knowledge of kidney and urinary tract development and their interdependency for normal function is essential for developing personalized care to ultimately improve patient outcomes.

Ureteropelvic Junction Obstruction Caused by Crossing Vessels in Infants and Young Children

BACKGROUND

To analyze the clinical characteristics of ureteropelvic junction obstruction (UPJO) caused by crossing vessels (CV) in infants and young children.

METHODS

A retrospective analysis was performed on children with UPJO who underwent primary surgery. Patients were classified into laparoscopic pyeloplasty (LP) and open pyeloplasty (OP) groups and classified as ≤3 or >3 (years old) groups. Children with CV-caused UPJO were identified.

RESULTS

A total of 747 patients were included. Ninety cases of CV were identified. The CV discovery rate was higher in the LP group (78/457, 17.1%) than in the OP group (12/290, 4.1%) (P < 0.001). In the ≤3 group, the CV discovery rate in the LP group (27/144, 18.8%) was higher than that in the OP group (11/274, 4.0%) (P < 0.001). In the LP group, there was no significant difference between ≤3 (27/144, 18.8%) and >3 (51/313, 16.3%) groups in the CV discovery rate. The rate in children with UPJO was not significantly different at any age (P > 0.05). Progressive aggravation of hydronephrosis (21/27, 77.8%) and symptomatic hydronephrosis (44/51, 86.3%) were the main surgical indications in the ≤3 and > 3 groups, respectively. There were no preoperatively confirmed cases of CV in the ≤3 group. In the OP group, five patients underwent reoperation, three of whom were due to failure to detect CV during the initial operation.

CONCLUSIONS

The CV distribution is similar in children with UPJO across all ages; CV in infants and young children are not rare. LP should be considered as CV are prone to being missed during OP.

LEVELS OF EVIDENCE

III.

Renal and Genitourinary Ultrasound Evaluation in Emergency and Critical Care: An Overview

Renal and genitourinary ultrasound are fundamental resources employed by emergency and critical care healthcare providers to make prompt diagnoses and perform ultrasound-guided procedures. At the bedside, ultrasound can aid in the diagnosis of relevant pathologies, such as post-renal obstruction or kidney stones, and life-threatening conditions such as aortic dissection or hemoperitoneum. A narrative overview was performed, providing an updated review of renal and genitourinary ultrasound for emergency and critical care healthcare providers, emphasizing its advantages and the latest advances in the field. A thorough summary that can be utilized as a guide for emergency and critical care healthcare providers is presented. The daily hemodynamic management of critically ill patients involves the implementation of new protocols, such as VexUS or the evaluation of the renal resistance index. The role of ultrasound in managing acute nephropathy and genitourinary issues is increasingly crucial given its bedside availability, thus this imaging modality not only facilitates the initiation of therapeutic interventions but also provides swift prognostic insights that are vital to provide tailored patient care. As further advances in ultrasound will arise, it is important for healthcare providers to foster the use of these technologies capable of improving patient outcomes.

Our experience of operated pediatric ureteropelvic junction obstruction patients

AIMS

Ureteropelvic junction obstruction (UPJO) may originate from extrinsic or intrinsic causes in children. The aim of this study is to present preoperative and postoperative data of our patients operated for UPJO.

METHODS

A total of 64 patients who underwent open pyeloplasty were investigated retrospectively. They were evaluated in terms of demographically, clinics, hydronephrosis, differential renal functions (DRFs), half-time tracer clearance (½TC), and histopathologic results. Patients' numerical results were stated as mean ± standard deviation (SD).

RESULTS

Male gender was more prevalent (n = 47, 73.4%) and mean age at surgery was 46.87 months. UPJO was located at the left side in 56.3% (n = 36), and at the right side in 39.1% (n = 25) of patients. It was bilateral in 4.7% (n = 3). Hydronephrosis was found antenatally in 68.8% (n = 44) of patients. The mean preoperative DRF was 49.7% (21-78%) and mean postoperative DRF was 49.2% (20-56%). Mean renal scintigraphic t1/2 was >20 min for all patients. The mean AP diameter was 21.58 mm (10-62 mm). Muscular hypertrophy was the most common pathological finding, mean length of excised segment was 10.26 mm (3-40 mm). Crossing vessel (CV) was detected in 17.18% (n = 11). The CV was statistically associated with increased age of operation, left side, and female gender. Statistically significant hydronephrosis was found in non-CV patients. Re-operation was required in seven patients (7.8%).

CONCLUSIONS

Intrinsic pathologies are more seen in the etiology of UPJO patients with antenatal diagnosis and this group needs operation at an earlier age. However, CV is found more commonly in patients who are diagnosed and operated at older ages.

Association between intraoperative anatomical variation and histopathological parameters in cases of ureteropelvic junction obstruction in children: A cross-sectional study

Introduction

The intraoperative anatomical findings (IOAF) of all ureteropelvic junction obstruction (UPJO) cases are not identical. Moreover, there is also controversy in the literature regarding histopathological (HP) findings in cases of UPJO. In the present study, we evaluated different IOAF and assessed their association with specific HP parameters.

Materials and Methods

This was a cross-sectional study set-up, which was carried out in a tertiary care centre. Children with UPJO who underwent surgery between 2017 and 2020 were enrolled. The following IOAF were noted: Type of pelvis (extrarenal or intrarenal), insertion of the ureter (high or normal), presence of lower pole crossing vessel (CV), negotiation of UPJ segment with double J stent (3 Fr) and length of internal narrowing (LIN) at UPJ. The resected segment of UPJ was assessed at three levels (pelvis, UPJ and ureter) for various HP parameters including fibrosis, oedema, inflammation and smooth muscle hypertrophy (SMH).

Results

Thirty-nine children were included in the study with a mean age of 31 months. The summary statistics of IOAF were intrarenal pelvis in 5 cases, high insertion of the ureter (HIU) in 9, CV in 6, negotiable UPJ in 23, and 16 cases showed LIN >1 cm. All cases showed SMH at the pelvis region and SMH with fibrosis at the UPJ region. At the pelvis region, there was an association between (1) HIU with oedema and chronic inflammation (CIF), (2) CV with CIF and (3) LIN with CIF and SMH. At the UPJ region, there was an association between (1) CV and negotiable UPJ with less fibrosis and (2) LIN with SMH. At the ureteric end, CV showed an association with less fibrosis and more CIF.

Conclusion

All UPJO cases have some common HP findings. Although, some particular IOAF, i.e., presence of CV, negotiable UPJ, HIU and LIN showed association with specific HP parameters.

Ureteropelvic junction obstruction in children by polar vessels: histological examination result

In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO) such as abnormal amounts of muscle and collagen deposition; extrinsic UPJO are rare and often due to crossing vessels (CVs). What is not clear is whether there is also intrinsic UPJ pathology in patients with CV. The aim of our study was to compare the histology of the two types of obstruction and to determine whether these histologic features are distinguishable enough to enable to identify the cause of obstruction based on histologic appearance alone. We retrospectively reviewed pathology reports of 38 children with UPJO that underwent surgery in our hospital from 2008 to 2022. The intrinsic and extrinsic groups consisted of 18 and 20 patients, respectively. After ematoxylin-eosin and Gomori's trichrome staining the specimens were scored for fibrosis and muscular hypertrophy in histhopatology, and CD117 antibody were used to detect interstitial Cajal-like cells. In our study, histological analyses revealed no differences between the CV and IUPJO specimens in terms of presence and degree of fibrosis and muscular hypertrophy; likewise, for presence of interstitial Cajal-like cells.

Functional Magnetic Resonance Urography in Ureteropelvic Junction Obstruction: Proposal for a Pediatric Quantitative Score

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is one of the most frequent causes of congenital hydronephrosis. It is essential to distinguish UPJO which needs surgical treatment. fMRU combines high quality morphological details of the kidney and excretory pathways with functional data.

OBJECTIVE

This study aims to introduce a new radiological score based on fMRU findings to be able to differentiate surgical from non-surgical kidneys.

MATERIALS AND METHODS

We retrospectively selected patients with hydronephrosis due to UPJO who underwent fMRU (January 2009-June 2018). A multidisciplinary team identified a list of fMRU morpho-functional predictive variables to be included in the analysis. To evaluate the role of different independent variables in predicting the outcome, a multivariable logistic regression model has been performed; the outcome variable was the surgical intervention. For each predictive variable, Odds Ratio and 95% Confidence Intervals were calculated. The likelihood ratio test was used to assess the significance of the variables. Using the regression model, we assigned a numerical value to each predictive variable, rounding up the beta-coefficients. The cut-off value of the total score was obtained from the ROC curve analysis.

RESULTS

A total of 192 patients were enrolled, corresponding to 200 pathological kidneys. All of them underwent fMRU; 135 were surgically treated, while 65 underwent ultrasound or MRU follow-up. Predictive variables significantly associated with surgery resulted to be the urographic phase, the presence of abnormal vessels, and a baseline anterior-posterior pelvic diameter >23 mm. Beta coefficients of the logistic regression model were then converted in scores. The ROC curve of the score showed high sensitivity (84.3%) and specificity (81.3%) with a cut-off > 2.5.

CONCLUSIONS

We propose a new fMRU score able to identify surgical vs. non-surgical kidneys with UPJO.

Early outcome findings of treatment for transperitoneal laparoscopy-assisted pyeloplasty

Background

We retrospectively analyzed the initial results of laparoscopic pyeloplasty, among pediatric patients undergoing the procedure by transperitoneal access.

Methods

We retrospectively reviewed the medical records of patients who were operated with transperitoneal laparoscopy-assisted pyeloplasty at our institution between 2015 and 2020.

Results

The mean age of the 51 patients (M/F = 36/15) was 59 ± 49.8 months. The mean preoperative renal pelvis anterior–posterior diameter was 32.9 ± 13.4 mm, and the relative renal function was 42 ± 12.1% on the operation side. Forty-three (84.3%) patients had no excretion on MAG3 examination preop. The number of patients with no excretion decreased to 10 (19.7%) after surgery. One of them underwent a successful endopyelotomy; eight of them underwent a successful laparoscopic re-pyeloplasty. There was nothing to do in only one patient whose DRF decreased to 11%. The mean anterior posterior diameter decreased significantly to 16.7 ± 11.2 mm after surgery (p < 0.001).

Conclusion

Preoperative increased renal pelvis anterior–posterior diameter detected in our study was found to be a risk factor in the failure of transperitoneal laparoscopy-assisted pyeloplasty procedure.

A comparative study between continuous and interrupted sutures in open pyeloplasty

BACKGROUND

Pelvi-ureteric junction obstruction (PUJO) is one of the common causes of obstructive uropathy dealt by urologists around the globe. The management of PUJO requires surgical intervention and pelvi-ureteral anastomosis is most time-consuming step in surgery and suturing plays a critical role for the good outcome of the surgery.

OBJECTIVE

To assess the outcomes of continuous or interrupted suturing in open pyeloplasties done for PUJ obstruction.

MATERIALS AND METHODS

This comparative study was conducted in the department of Urology in a tertiary care hospital of eastern India. A total of 60 patients with pelviureteric junction obstruction were included as per inclusion and exclusion criteria and divided into two groups depending upon whether continuous (Group A) or interrupted (Group B) suturing was done. Both groups were compared for mean operative time, mean suturing time, duration of post-operative drainage, mean drain output, post-operative hospital stay, postoperative GFR and improvement in GFR.

RESULTS

Out of 60 patients continuous and interrupted suturing was done in 30 patients in both arms. Out of 60 cases there were 46 (76.66%) males and 14 (23.33%) females with a M:F ratio of 1:0.30. The mean age in group A and group B was found to be 30.06 ± 8.28 and 27.63 ± 6.07, respectively. Mean operative time, mean suturing time, duration of post-operative drainage, mean drain output and postoperative hospital stay were found to be higher in interrupted suture group and the difference was found to be statistically highly significant (p < 0.0001). The complication rates and recurrence rates were found comparable in both the cases with no statistically significant difference (p > 0.05).

CONCLUSION

Continuous suturing technique for pyeloplasty is preferable as it is found to have a lower mean operative time, mean suturing time, duration of post-operative drainage, mean drain output and postoperative hospital stay.

Crossing vessels with suspension versus transposition in laparoscopic pyeloplasty of patients with ureteropelvic junction obstruction: a retrospective study

Purpose

To compare the effects of two different methods of laparoscopic pyeloplasty for the treatment of crossing vessels.

Methods

From January 2016 to August 2019, 33 patients with ureteropelvic junction obstruction (UPJO) underwent laparoscopic pyeloplasty at our center, including 21 men and 12 women, ranging from 14 to 66 years of age. There were 20 and 13 cases on the left and right sides, respectively. Patients underwent laparoscopic pyeloplasty (Anderson-Hynes operation). During the operation, either a Hem-o-lok clip suspension or transposition was used to treat the crossing vessels. The double-J stent was removed 8 weeks after the operation. The clinical data of patients were collected and follow-ups were regularly performed after the operation.

Results

All the crossing vessels were successfully preserved, and none of them were severed during the operation. The average operation time was 210.6 ± 58.9 min in this group and the average time to manage the crossing vessel was 8.0 ± 3.5 min, 5.9 ± 1.4 min in the suspension group, and 11.7 ± 3.0 min in the transposition group. The dilation of the affected side was 4.8 ± 1.5 cm before operation and 1.2 ± 1.3 cm 3 months after operation. The difference was statistically significant (P < 0.05). Follow-up to February 2020 showed no significant changes in the kidney size in all patients and hydronephrosis was relieved.

Conclusion

For UPJO patients with crossing vessel compression, the method of Hem-o-lok suspension or vascular transposition can be used to relieve crossing vascular compression and improve the success of pyeloplasty.

Application of three-dimensional image reconstruction technology based on high-resolution CT in pyeloplasty

Background

Three-dimensional (3D) image reconstruction technology is widely used in surgical operations for its intuitive visualization. Pyeloplasty requiresprecise cutting and suturing. The reconstruction technology can accurately determine the location and scope of the stenosis at the junction of the renal pelvis and ureter and the relationship with the surrounding vasculature. The purpose of this article is to retrospective evaluate the application value of image reconstruction technology in pyeloplasty based on high-resolution 3D CT images.

Methods

A total of 20 patients with renal pelvic ureteral junction obstruction admitted to our hospital from August 2019 to August 2020 were selected. In this group, left pyeloplasty was performed in 8 patients and right pyeloplasty in 12 patients. In terms of conditions, there was 1 case with secondary pyeloplasty, 6 cases of patients with kidney stones, 2 cases with renal ectopic blood vessels, 1 case with renal prolapse, 1 case with horseshoe kidney, and 1 case with ureteral polyps. There were 12 males and 8 females, with an average age of 34.65±10.67 years and an average body mass index (BMI) of 22.48±3.03 kg/m². In all patients, 3D CT reconstruction technology was used to guide the formulation of robot-assisted laparoscopic pyeloplasty plans; verify the consistency between the actual operation and the preoperative planning; and observe the operation time, blood loss, postoperative exhaust time, indwelling drainage tube time, and follow-up for comorbidities.

Results

The operation was successful in all 20 patients. The actual operation was 100% consistent with the preoperative planning, the operative time was 160.80±63.26 min, the intraoperative blood loss was 47±30.45 mL, the postoperative exhaust time was 1.15±0.37 days, the drainage tube indwelling time was 4.35±1.50 days, and the average follow-up time was 7.95±3.41 months. There were no complications.

Conclusions

Three-dimensional image reconstruction technology based on high-resolution CT has high clinical application value in the treatment of ureteropelvic junction obstruction (UPJO), which simplifies the operation process and shortens the operation time, and is a valuable tool for auxiliary surgeons in devising the operation plan.

Morphology of the fetal renal pelvis during the second trimester: Comparing genders

OBJECTIVES

Many studies of neonates have shown that renal pelvis ectasia is more common in boys. The aim of this study was to determine whether there are structural differences in the renal pelvis between male and female fetuses in the second trimester of gestation.

MATERIAL AND METHODS

We studied 34 renal pelvises obtained from 34 human fetuses (17 males and 17 females), ranging in age from 13 to 23 weeks postconception. The renal pelvis tissue was stained with Masson's trichrome to quantify connective and smooth muscle cells (SMC). The tissue also was fixed for scanning electron microscopy (SEM) in a modified Karnovsky solution. The images were captured with an Olympus BX51 microscope and Olympus DP70 camera. The stereological analysis was done with the Image-Pro and ImageJ programs, using a grid to determine volumetric densities (Vv). Means were statistically compared using simple linear correlation and the Mann-Whitney test (p<0.05).

RESULTS

Quantitative analysis indicated differences (p=0.0275) in Vv of connective tissue in male renal pelvises (mean=55.3%) compared to female ones (mean=51.46%). Quantitative analysis indicated a significant difference (p=0.0002) in SMC in male renal pelvises (mean=12.57%) compared to female ones (mean=16.22%). When we compared the SMC at different ages, we did not find any correlation in male (r²=0.2657, p=0.3027) or female fetuses (r²=0.3798, p=0.1326). When we compared the connective tissue at different ages, we did not find any correlation in female fetuses (r²=0.3798, p=0.2870), but we did observe a positive correlation between the connective tissue and age in male fetuses (r²=0.8308, p<0.0001). SEM showed that the collagen fibers had no differences between male and female.

CONCLUSION

The renal pelvis presents significant structural differences between male and female fetuses. The renal pelvis in males had less SMC and presented a positive correlation of connective tissue with age and the renal pelvis in female had less connective tissue without correlation with the age.

LEVEL OF EVIDENCE

III.

Acute Presentation of Giant Hydronephrosis in an Adult

Giant hydronephrosis is defined as a dilated collecting system containing more than one liter of fluid. The diagnosis of giant hydronephrosis is rare due to improved diagnostics and the liberal use of abdominal imaging. Herein we report a 40-year-old woman who presented with acute onset abdominal pain and was diagnosed with giant hydronephrosis. She underwent a simple open nephrectomy and made an unremarkable recovery. Although giant hydronephrosis due to ureteropelvic junction obstruction is common in the pediatric and adolescent age group, it rarely presents in adults. Acute presentations, like abdominal pain, are exceedingly rare. Judicial use of cross-sectional imaging, as in our patient, can confirm the diagnosis and help in successful management.

[Treatment of crossing vessels in laparoscopic pyeloplasty]

OBJECTIVE

To investigate the management of crossing vessels compression in laparoscopic pyeloplasty.

METHODS

From January 2016 to June 2018, a total of 21 patients who were admitted to Peking University People's Hospital with ureteropelvic junction obstruction (UPJO) associated with crossing vascular compression were reviewed. There were 15 males and 6 females who formed this group, with a mean age of (33.9±15.0) years. There were 4 cases of mild hydronephrosis, 12 cases of moderate hydronephrosis and 5 cases of severe hydronephrosis before operation. All the patients underwent laparoscopic pyeloplasty in our hospital, including 13 on the left and 8 on the right. Laparoscopic pyeloplasty (Anderson-Hynes) were performed in all the patients. Hem-o-lok suspension (14 cases in the suspension group) or translocation of the crossing vessels (7 cases in the translocation group) were used for the intraoperative management of the crossing vessels. Double J tubes were removed 8 weeks postoperatively. The patient demographic data were collected (including operation time, treatment time of crossing vessels, intraoperative blood loss, time of drainage tube removal after operation, and average length of hospital stay), postoperative outcomes were evaluated and the patients were followed up regularly.

RESULTS

In all the patients, the crossing vessels were successfully reserved, and none of them were ligated intra-operatively. Mean operative times were (202.2±57.0) min. The duration of intraoperative treatment of crossing vessels was (10.5±3.2) min, (6.1±2.0) min in the suspension group, and (13.7±5.2) min in the translocation group, respectively. Intraoperative blood loss was (47.8±25.6) mL, postoperative drainage time was (4.8±2.6) d, and length of hospital stay was (11.5±3.3) d. Postoperative slight urinary leakage occurred in 1 case. Preoperative pyelectasis of the affected side of all the patients was (3.4±1.7) cm, compared with postoperative pyelectasis of (1.9±1.3) cm. The difference was statistically significant (P<0.05). Postoperative follow-up of all the patients was carried out until December 2018. There was no significant difference in kidney size in all the patients before or after the operations, and hydronephrosis was alleviated compared with that before surgery.

CONCLUSION

For UPJO patients with crossing vascular compression, according to the location of the crossing vessels, Hem-o-lok suspension or vessel transposition can be adopted to relieve the crossing vascular compression and improve the success rate of the surgery.

Surgical validation of functional magnetic resonance urography in the study of ureteropelvic junction obstruction in a pediatric cohort

INTRODUCTION

Ureteropelvic junction obstruction (UPJO) is one of the most common urological diseases in children. The etiology can be intrinsic, extrinsic (crossing vessel [CV] or adhesions), or mixed. To date, ultrasonography and scintigraphy are considered gold-standard imaging techniques for the study of UPJO. Functional magnetic resonance urography (fMRU) combines anatomical and functional information and has been recently evaluated for the detection of CVs in UPJO.

OBJECTIVE

The objective of the study was to evaluate the concordance between fMRU and surgery in determining the etiology of UPJO and the presence of obstructing/non-obstructing CVs.

STUDY DESIGN

Patients with unilateral hydronephrosis who underwent surgery after an fMRU were included in the sample. Surgical data regarding the etiology of UPJO were compared with radiological results. The etiology was divided into intrinsic, extrinsic due to CV, extrinsic due to adhesions, and mixed or cicatricial (postoperative). The concordance was calculated by means of the Cohen's kappa coefficient.

RESULTS

The observed agreement between fMRU and surgical findings regarding the etiology and the presence of CV were 83.2% and 89.4%, respectively (with substantial Cohen's kappa coefficient). The sensitivity and specificity of fMRU were 0.84 and 0.93, respectively; the positive predictive value (PPV) and negative predictive value (NPV) were 0.889 and 0.897, respectively. The observed agreement regarding the type of vessel was 88.3% with a Cohen's kappa coefficient of 0.787 (substantial).

DISCUSSION

In children with hydronephrosis, it is very important for the surgeon to quantify the extent of dilation, define the etiology of the obstruction, and the presence or absence of CVs. fMRU is a 'one-stop-shop' technique which provides both anatomical and functional information showing a high concordance with surgical findings, avoiding radiation exposure.

CONCLUSIONS

fMRU should be considered a valid imaging technique in the study of pediatric UPJO, as it provides the surgeon with important information regarding the etiology of the obstruction for the preoperative planning.

Pathologic Specimens at Time of Pyeloplasty: Frequency and Practice Patterns

OBJECTIVE

To assess national and regional practice patterns and rates of pathologic specimen identification sent at time of pyeloplasty, as well as project associated costs, we used a national administrative database. The rate at which the excised ureteropelvic junction obstruction (UPJO) is sent for pathologic identification is variable, arguably without a clear clinical purpose.

MATERIALS / METHODS

Utilizing a national administrative database of privately insured patients, 1496 individual cases were identified using international classification of diseases (ICD) and Current Procedural Terminology (CPT) coding. Patients from 0-18 years of age were included whose pyeloplasty was performed during 2010-2014. Patients who were and were not billed for pathologic identification at time of surgery were identified. Regional practice patterns and associated costs were determined.

RESULTS

One thousand four hundred and ninety-six pyeloplasty cases were identified (68.2% males). Specimens were sent for pathologic identification in 827 cases (55%). Average age was 5.8 years for those without pathology and 4.6 years for those in whom a specimen was billed. Regionally, the Western United States was least likely to bill for surgical pathology (49%). The parental out-of-pocket payment for the encounter was on average $1518 for cases in which pathology was sent and $1398 for those cases for which no pathology bill was identified.

CONCLUSION

Pediatric pyeloplasty is a common surgical procedure for which a pathologic specimen is sent in as many as 55% of cases in this cohort. Regional differences exist across the country and there is an associated slightly higher out-of-pocket cost in cases for which pathologic specimens are sent at time of pyeloplasty.

Histopathology in Ureteropelvic Junction Obstruction With and Without Crossing Vessels

OBJECTIVE

To determine if the histopathology of the ureteropelvic junction differs between those with and without crossing vessels who present with a ureteropelvic junction obstruction (UPJO).

MATERIALS AND METHODS

Our database was queried for patients undergoing pyeloplasty (Current procedural terminology 50400, 50405, and 50544) between June 1, 2002, and March 10, 2016. We excluded patients with other renal anatomic abnormalities and patients undergoing surgery for upper tract tumor. One genitourinary pathologist reviewed all slides for muscle hypertrophy, fibrosis, edema, and inflammation. Statistics were modeled in SAS 9.4 (SAS, Cary, NC) using logistic regression with maximum likelihood.

RESULTS

A total of 178 patients met the inclusion criteria, and pathology slides were available for 136 patients. Thirty-three patients had crossing vessels in association with a UPJO. The degrees of muscle hypertrophy (P = .89) and fibrosis (P = .17) were not predictive of etiology. The odds of a crossing vessel increased by 4.3 times (95% confidence interval 1.8-9.9) when edema was present (P = .009) and by 4.4 (95% confidence interval 1.4-13.7) times when inflammation was present (P = .0103).

CONCLUSION

In the largest pathology series to date, histopathology showed increased inflammation in the presence of a crossing vessel but a similar composition of muscle and fibrosis. These data suggest that UPJO with an associated lower-pole vessel may represent a chronic process, which would explain why patients with a crossing vessel present later in life.

Sonic hedgehog, TBX18, and TSHZ3 proteins involved in pyeloureteral motility development are overexpressed in ureteropelvic junction obstruction. An immunohistochemical, histopathological, and clinical comparative study

Objectives:

To compare pathological samples obtained from cases that underwent surgery for ureteropelvic junction (UPJ) obstruction with samples obtained during autopsies of subjects.

Methods:

Retrospectively, 42 patients who had undergone surgery due to UPJ obstruction (group 1) were included in the study. Histopathological and immunohistochemical features for sonic hedgehog (SHH), TBX18, and TSHZ3 of UPJ were evaluated and findings were compared with 20 autopsy cases (group 2).

Results:

In group 1, the scores were statistically significantly higher in terms of cytoplasmic SHH, nuclear TBX18, cytoplasmic and nuclear TSHZ3 staining. Statistically, no correlation was found between age and the staining scores belonging to these 3 antibodies in group 1 and group 2. Intense inflammation was found to be related with nuclear staining for TBX18.

Conclusion:

Gene product expressions of SHH, TBX18 and TSHZ3 are statistically higher in patients with UPJ obstruction, when compared with control group. The explanation may be the reactivation of the processes, which had shown their effects in the embryological period, due to the chronic inflammation and long-term micro-trauma created by the disease.