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.

Recurrent UPJ obstruction following paediatric pyeloplasty is associated with an initial <2.5cm incision open surgical approach

OBJECTIVES

To determine the risk factors that affect surgical outcomes for pediatric pyeloplasty, and whether this may be related to the choice of operative approach.

METHODS

A retrospective cohort study was performed to evaluate clinicodemographic and operative characteristics of children undergoing dismemberment pyeloplasty by 2 senior pediatric urologists in our tertiary institution between Jan 2008 - Dec 2017. Outcomes included overall complications, re-stenosis, and revision pyeloplasty based on clinic-radiological parameters. Bivariate analysis with Chi-square and Mann-Whitney U test followed by multivariate logistic regression with backward likelihood analysis determined an adjusted effect estimate of the identified significant indicators for inferior peri-operative outcomes related to management.

RESULTS

A total of 185 (93 open, 92 Laparoscopic) cases with an average follow-up of 31.3±27.4 months were analyzed. Complications occurred in 21 (11.4%) patients. 12 (6.5%) experienced recurrent UPJ obstruction with 10 (5.4%) undergoing redo-pyeloplasty. Of these, 9 were performed open and 1 laparoscopically. Multivariate logistic regression identified open pyeloplasty as an independent predictor for overall complications (HR 3.29, 95%CI 1.14, 9.51), recurrent UPJ obstruction (HR 49.8, 95%CI 3.09, 803.2) and redo-pyeloplasty (HR 9.75, 95%CI 1.21, 78.6) compared to a laparoscopic approach. Missed crossing vessels were identified in seven redo-cases, which all were from prior open pyeloplasty.

CONCLUSIONS

An initial open approach was identified as an independent predictor of future complications due to a higher incidence missed crossing vessels at initial repair. Surgeons need to remain especially mindful of this phenomenon when working in a confined open field.

Lower ureteral compression through external vascular elongation in a cyclist: A case report

Introduction and importance

There is sparse literature about lower ureteric obstruction due to aberrant blood vessels. We report a case of a patient who was referred to our hospital due to left sided flank pain caused by external compression of the distal ureter.

Case presentation

A 47-year-old male patient presented with left sided flank pain. A computed tomography scan revealed external compression of the lower ureter. Hypertrophy of the psoas muscle due to extensive cycling for 20 years lead to concomitant kinking and elongation of the iliacal vessels which caused the distal ureteric obstruction. Robotic-assisted laparoscopic ureterocystoneostomy with psoas hitch technique was performed.

Clinical discussion

Lower ureteric obstruction, mostly seen in children, is mostly caused by vascular anomalies such as a persistent umbilical artery. After literature review, we presume it to be the first reported case of distal ureteric obstruction caused by external vascular elongation.

Conclusion

The external elongation of pelvic vessels due to excessive cycling and the concomitant extrinsic compression of the distal ureter should be considered as rare but possible cause of lower uretic obstructions.

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A 47-year-old cyclist was admitted with left sided flank pain

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Excessive cycling lead to elongation of the iliacal vessels and concomitant hydronephrosis

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External compression of distal ureter due to pelvic elongation is a rare differential diagnosis of lower ureteric obstruction

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Robotic assisted ureterocystoneostomy as a treatment option was performed

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.

[Pyeloplasty and vascular crossing detection: Surgical approach influence on pieloureteral junction stricture.]

OBJECTIVE

Polar vessels are related with pyelo-ureteral stenosis (PUE) in 5-10% of the patients. In the 24% of these cases an intrinsic cause of stenosis can also be found. An increased incidence of polar vessels is found in laparoscopic surgery, compare to open procedures. Our study analyses this difference in our hospital, studying its influence in the aetiology of the disease.MATERIAL AND METHODS: Descriptive and retrospective study of patients operated in our hospital of pyeloplasty, because of PUE between 2009 and 2017. Patients have been divided in two groups: operated by laparoscopy (PL), or operated by conventional surgery (PA). All cases in which polar vessels were seen in TC where excluded. Each group included 47 patients.

RESULTS

We found no statistical differences in the age of surgery of the two groups (36,1±41,3 months PL/31,8±37,2 months PA; p=0.527). Overall, 18 polar vessels were found, 15 in PL and 3 in PA. 6 patients of the PA group presented recurrence of the obstruction, and in 2 of them, polar vessels were found in the second surgery. All the 18th cases presented anomalies in the histological study related with inflammation or fibrosis.

CONCLUSIONS

The laparoscopic approach allows a better vision of crossing vessels in the cases of extrinsic PUE. Dismembered pyeloplasty might be the best treatment, as an intrinsic cause of obstruction cannot be ruled out according to the observed histological alterations.

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.

Retroperitoneal laparoscopic non-dismembered pyeloplasty for uretero-pelvic junction obstruction due to crossing vessels: A matched-paired analysis and review of literature

OBJECTIVE

To compare laparoscopic Anderson-Hynes pyeloplasty (LAHP) and retroperitoneal laparoscopic YV-pyeloplasty (LRYVP) in ureteropelvic junction obstruction (UPJ) in presence of a crossing vessels (CV).

METHODS

Our database showed 380 UPJO-cases,who underwent laparoscopic retroperitoneal surgery during the last 2 decades including 206 non-dismembered LRYVP, 157 dismembered pyeloplasties LAHP, and 17 cases of laparoscopic ureterolysis. Among them 198 cases were suitable for a matched-pair (2:1) analysis comparing laparoscopic retroperitoneal non-dismembered LRYVP (Group 1, n = 131) and dismembered LAHP (Group 2, n = 67) in presence of a crossing vessel. Patients were matched according to age, gender, kidney functions, and obstruction grade. Complications were graded according to modified Clavien-classification.

RESULTS

Comparative data were similar between both groups (LRYVP vs. LAHP) including mean operating time (112 min vs. 114 min), complication rates (4.2% vs. 7.3%) mainly Grade 1-2 according to Clavien classification, and success rates (90% vs. 89%). These results reflected in the reviewed literature indicate that LRYVP provides the advantage of minimal dissection in case of CV with similar outcome. However, redundant pelvis and anteriorly crossing vessels still require a dismembered pyeloplasty LAHP.

CONCLUSION

LRYVP has achieved similar results compared with the previous golden standard of open surgery, especially in case of crossing vessels apart from presence of a redundant pelvis or anteriorly crossing vessel. This can be further improved when using the small access retroperitoneoscopic technique respectively mini-laparoscopy.

Hydronephrosis and crossing vessels in children: Optimization of diagnostic-therapeutic pathway and analysis of color Doppler ultrasound and magnetic resonance urography diagnostic accuracy

INTRODUCTION

Ureteropelvic junction obstruction (UPJO) is one of the most frequent urological diseases affecting the pediatric population. It can be due to both intrinsic stenosis of the junction and extrinsic causes such as the presence of crossing vessels (CVs), which can be detected by color Doppler ultrasound (CD-US). Magnetic resonance urography (MRU) is a good alternative, but sedation and infusion of a contrast agent are required.

OBJECTIVE

The aim of this study was to analyze the diagnostic accuracy of CD-US and MRU in visualizing CVs in pediatric hydronephrosis, in order to decide the correct diagnostic pathway in the pre-operative phase.

MATERIAL AND METHODS

A retrospective review was performed of medical records for all patients who underwent surgical treatment for hydronephrosis from August 2006 to February 2016. Ultrasound and scintigraphy had been performed on all patients. Data about CD-US and MRU were collected. A high-level technology ultrasound scanner and a 1.5 T MR scanner were used. The presence of CVs at surgery was considered the gold standard. Sensitivity, specificity, positive and negative predictive values (NPV) were calculated and reported for both of the imaging techniques.

RESULTS

A total of 220 clinical charts were reviewed. Seventy-three CVs were identified at surgery (33.2% of UPJO). The median age was statistically higher in the group with CVs compared to the group without CVs (P < 0.001). The sensitivity and NPV of CD-US in detecting CVs were higher than MRU (sensitivity 93.3% vs. 71.7%, NPV 95.7% vs. 77.6%, respectively).

DISCUSSION

According to the data, CD-US had higher sensitivity and NPV than MRU, resulting in superior detection of CVs. It is important for a surgeon to know that a child has a CV, especially in older children in which the incidence of extrinsic UPJO is higher. The main limitation of this study was the presence of incomplete data, due to the retrospectivity.

CONCLUSIONS

In the pre-operative phase, the CD-US should be considered as the investigation of choice to detect CVs in children with hydronephrosis (Summary Fig). Moreover, CD-US has lower costs than MRU, and sedation with infusion of contrast agent is unnecessary. For the future, it could be useful to lead a prospective comparison between the two imaging techniques.

Pediatric ureteropelvic junction obstruction: can magnetic resonance urography identify crossing vessels?

BACKGROUND

MR Urography (MRU) is an increasingly used imaging modality for the evaluation of pediatric genitourinary obstruction.

OBJECTIVE

To determine whether pediatric MR urography (MRU) reliably detects crossing vessels in the setting of suspected ureteropelvic junction (UPJ) obstruction. The clinical significance of these vessels was also evaluated.

MATERIALS AND METHODS

We identified pediatric patients diagnosed with UPJ obstruction by MRU between May 2009 and June 2014. MRU studies were evaluated by two pediatric radiologists for the presence or absence of crossing vessels. Ancillary imaging findings such as laterality, parenchymal thinning/scarring, trapped fluid in the proximal ureter, and presence of renal parenchymal edema were also evaluated. Imaging findings were compared to surgical findings. We used the Mann-Whitney U test to compare continuous data and the Fisher exact test to compare proportions.

RESULTS

Twenty-four of 25 (96%) UPJ obstructions identified by MRU were surgically confirmed. MRU identified crossing vessels in 10 of these cases, with 9 cases confirmed intraoperatively (κ = 0.92 [95% CI: 0.75, 1.0]). Crossing vessels were determined to be the primary cause of UPJ obstruction in 7/9 children intraoperatively, while in two children the vessels were deemed incidental and noncontributory to the urinary tract obstruction. There was no significant difference in age or the proportions of ancillary findings when comparing children without and with obstructing vessels.

CONCLUSION

MRU allows detection of crossing vessels in pediatric UPJ obstruction. Although these vessels are the primary cause of obstruction in some children, they are incidental and non-contributory in others. Our study failed to convincingly identify any significant predictors (e.g., age or presence of renal parenchymal edema) that indicate when a crossing vessel is the primary cause of obstruction.