Comparison of Contrast-Enhanced Color Doppler Imaging (CDI), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) for the Detection of Crossing Vessels in Patients with Ureteropelvic Junction Obstruction (UPJO)

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.

Vascular compression syndromes in the abdomen and pelvis: a concise pictorial review

Vascular compression syndromes are a diverse group of pathologies that can manifest asymptomatically and incidentally in otherwise healthy individuals or symptomatically with a spectrum of presentations. Due to their relative rarity, these syndromes are often poorly understood and overlooked. Early identification of these syndromes can have a significant impact on subsequent clinical management. This pictorial review provides a concise summary of seven vascular compression syndromes within the abdomen and pelvis including median arcuate ligament (MAL) syndrome, superior mesenteric artery (SMA) syndrome, nutcracker syndrome (NCS), May-Thurner syndrome (MTS), ureteropelvic junction obstruction (UPJO), vascular compression of the ureter, and portal biliopathy. The demographics, pathophysiology, predisposing factors, and expected treatment for each compression syndrome are reviewed. Salient imaging features of each entity are illustrated through imaging examples using multiple modalities including ultrasound, fluoroscopy, CT, and MRI.

Outcomes of laparoscopic pyeloplasty and impact of an enhanced recovery protocol

<b>Purpose:</b> The study aims to analyze the enhanced recovery protocol’s (ERP) effectiveness in a comparative study of elective surgeries for ureteropelvic junction obstruction (UPJO).<br /> <b>Methods:</b> The prospective study included 30 patients with UPJO who underwent laparoscopic pyeloplasty in 2018-2021.<br /> <b>Results:</b> Postoperative complications developed rarely, and their frequency and severity were comparable. Independent predictors of UPJO recurrence were the spine osteochondrosis &gt;II period (HR 13.97; 95% CI 1.26; 154.8; p=0.032), the concretions self-discharge (HR 28.49; 95% CI 1.78; 455.62; p=0.018), surgical operation duration &gt; 110 minutes (HR 44.7; 95% CI 3.95; 505.4; p=0.002) and previous nephrostomy (HR 1.07; 95% CI 1.02; 1.13; p=0.002).<br /> <b>Conclusions:</b> In the surgical treatment of UPJO, it is advisable to use ERPs, as this allows achieving a better treatment quality with comparable results.

Ureteropelvic Junction Obstruction/Hydronephrosis

Congenital hydronephrosis can be classified and managed based on the Urinary Tract Dilation consensus scoring system. Ureteropelvic junction obstruction is one of the most common causes of hydronephrosis in the pediatric population. Although most cases can be managed conservatively with follow-up and serial imaging, some patients need surgical repair because of renal function deterioration, infections, or symptoms. Additional research to create predictive algorithms or develop noninvasive biomarkers for renal deterioration is necessary to better identify surgical candidates. The robotic-assisted approach for pyeloplasty is becoming increasingly widespread and associated with shorter hospital stay, high success rates, and low complication rates.

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.

Rare Causes of Hydronephrosis in Adults and Diagnosis Algorithm: Analysis of 100 Cases During 15 Years

Introduction Hydronephrosis (HN) is a common pathology that is with/without obstruction. HN should be promptly addressed; otherwise, it progresses to cause impaired kidney function. This study was conducted to define the diagnosis algorithm and poor prognostic parameters used to evaluate unknown HN. Materials and Methods This study enrolled 100 patients who were over 20 years of age and were admitted to the center between 2001 and 2015 for the diagnosis and treatment of HN. Although initial diagnostic tests were applied, the HN etiology of the patients could not be found in ambulatory conditions; therefore, they were hospitalized to seek the causes for their HN. Patients who had a malignancy or tuberculosis or any previous ureteral injury were excluded. Results Of these cases, 29 were on both sides, whereas 42 were on the left side. Despite further investigations, the etiology was not determined in five patients. The frequency of malignancy in patients with hematuria (5/15) was two times higher than in patients without hematuria (33% vs. 17.6%; p = 0.01). Additionally, the malignancy rate was significantly higher in patients with weight loss (100%) than those without weight loss (OR: 6.25; p < 0.001). Conclusions Further investigation is recommended to define the precise etiology of HN. Hematuria and weight loss should be considered poor predictive factors during diagnosis.

Pyeloplasty for pelviureteric obstruction junction obstruction

Pelviureteric junction obstruction (PUJO) is a common clinical presentation. Patients require investigation with biochemistry and imaging in the form of computed tomography and diuretic renography. The gold-standard pyeloplasty treatment is minimally invasive pyeloplasty. Here we discuss a typical presentation of PUJO and discuss key questions in the investigation, management and follow-up of this condition, including a review of the treatment options.

Level of evidence: 3a

Pediatric congenital hydronephrosis (ureteropelvic junction obstruction): Medical management guide

The prevalence of asymptomatic hydronephrosis, now detected by ultrasonography, has increased. However, definitive management guidelines for the management of congenital hydronephrosis have not been established. The Japanese Society of Pediatric Urology created a "medical management guide" based on new findings for physicians practicing pediatric urology. We developed a medical management guide focused on congenital hydronephrosis caused by ureteropelvic junction obstruction. This medical management guide consists of the definition, pathophysiology, epidemiology, diagnosis, classification, treatment using a clinical management algorithm of hydronephrosis and the long-term course of the disease. The aim of hydronephrosis management is to determine whether surgery should be carried out to avoid renal dysfunction, as there is a possibility for improvement without intervention. Ultrasonography is essential to make treatment decisions. Management is determined by a comprehensive assessment, including the degree of hydronephrosis, anterior-posterior diameter of the renal pelvis and, if necessary, a nuclear medicine evaluation of the status of urine drainage and renal function.

Management of ureteropelvic junction obstruction in children-a roundtable discussion

The investigation, management and follow-up of paediatric ureteropelvic junction obstruction is not standardized. The Young Pediatric Urology Committee of the European Society of Pediatric Urology interviewed five experts in the field on various aspects of management and compared this with published literature.

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.

Non-contrast-enhanced magnetic resonance angiography for detecting crossing renal vessels in infants and young children: comparison with contrast-enhanced angiography and surgical findings

BACKGROUND

Knowing that ureteropelvic junction obstruction is due to a crossing renal vessel is essential in choosing the appropriate surgical treatment.

OBJECTIVE

To evaluate the diagnostic accuracy of non-contrast magnetic resonance (MR) angiography in identifying crossing renal vessels in children younger than 4 years old with unilateral hydronephrosis.

MATERIALS AND METHODS

A retrospective review of preoperative MR urography of children with unilateral hydronephrosis was conducted by two independent readers. The presence or absence of crossing renal vessels was identified and compared with surgical findings.

RESULTS

Twenty-nine patients were included. The disagreement between MR angiography with and without contrast enhancement in detecting a crossing renal vessel was 8%. The disagreement between non-contrast-enhanced MR and surgical findings was 17%. The disagreement between contrast-enhanced MR angiography and surgical findings was 25%. The balanced triggered angiography without contrast enhancement had a sensitivity of 70% (95% confidence interval [CI]: 35-93%) and a specificity of 93% (95% CI: 66-100%). Contrast-enhanced MR angiography had a sensitivity of 56% (95% CI: 21-86%) and a specificity of 91%. (95% CI: 59-100%).

CONCLUSION

MR without contrast enhancement may be a reliable, valid and safe alternative to contrast-enhanced MR angiography for identifying crossing renal vessels.

Percutaneous retropelvic endopyelotomy for treatment of ureteropelvic junction obstruction

Purpose:

A new minimally invasive approach for endopyelotomy for the treatment of ureteropelvic junction obstruction (UPJO) is described. The results are compared with those of other lines of treatment.

Materials and Methods:

A total of 39 patients with UPJO underwent percutaneous retropelvic endopyelotomy. Retrograde percutaneous renal access, using the Lawson catheter and deflecting guidewire, was done for creation of the nephrostomy tract. Using holmium laser through a 28-Fr nephroscope, a small window was made in the posterolateral surface of the renal pelvis. The nephroscope was advanced from the renal pelvis to the retropelvic space through that window. Crossing vessels were easily detected and were either coagulated or avoided. The window incision was extended distally, and the narrow ureteropelvic junction (UPJ) was incised using holmium laser.

Results:

The entire procedure was done in the supine position within 1 h. The presence of secondary stones, hugely dilated renal pelvis, high insertion of the UPJ, and whether UPJO was primary or secondary, did not alter the results. The only factor that affected the results was split function of the obstructed renal unit. The success rate was 100% when the split function exceeded 35%. When the split function was <35%, the success rate dropped to 56%.

Conclusion:

Percutaneous retropelvic endopyelotomy is a promising approach for the treatment of UPJO that gave favorable results. The use of the nephroscope provided a wide visual field. The wide-field facilitated detection of crossing blood vessels with no incident of vascular injury. It also facilitated endopyelotomy with high precision. Ureteral injury was not a risk factor.

Minimally Invasive Treatment of Pediatric Extrinsic Ureteropelvic Junction Obstruction by Crossing Polar Vessels: Is Vascular Hitching a Definitive Solution? Report of a Multicenter Survey

BACKGROUND

This article aimed to evaluate the outcome of laparoscopic vascular hitch (VH) as an effective alternative to dismembered pyeloplasty in the treatment of children with extrinsic ureteropelvic junction obstruction (UPJO) by crossing vessels (CVs), by reporting the experience of three Italian centers of Pediatric Surgery.

METHODS

From 2006 to 2014, 54 children (18 girls and 36 boys, average age 10.7 years) affected by suspected extrinsic UPJO by CV were treated in three different institutions: 51 patients underwent laparoscopic VH, while 3 patients, in which a coexisting intrinsic etiology of UPJO was doubtful, underwent laparoscopic dismembered pyeloplasty. Preoperative diagnostic workup included: ultrasound (US)/Doppler scan, mercaptoacetyltriglycine (MAG3)-renal scan, and functional-magnetic-resonance-urography (fMRU). Symptoms at presentation were recurrent abdominal/flank pain and hematuria. All patients presented intermittent hydronephrosis (range 18-100 mm) on US and an obstructive pattern on MAG3 renogram.

RESULTS

Average operative time was 108 minutes, and average hospital stay was 1.8 days. As for complications, we reported a small abdominal wall hematoma and a high UPJ distortion without obstruction in 2 patients, not requiring reintervention (grade I Clavien-Dindo). At follow-up (range 12-96 months), all patients reported resolution of symptoms, decrease in the hydronephrosis grade, and improved drainage on MAG3 renogram.

CONCLUSIONS

Our results demonstrated the safety and efficacy of laparoscopic VH for treatment of extrinsic UPJO by CV, registering excellent outcomes in a very selected patient population. The careful selection of patients through intraoperative assessment of anatomical and functional aspects is a crucial step to confirm indications for VH and maintain a high success rate with the procedure. We believe that any concerns regarding the coexistence of intrinsic stenosis should certainly lead to opening the collecting system and to performing a classic dismembered pyeloplasty.

Long-term results with the laparoscopic transposition of renal lower pole crossing vessels

BACKGROUND

For the treatment of ureterovascular pelviureteric junction obstruction (PUJO), transposition of lower pole crossing vessels (LPCV) has been described as an alternative to dismembered pyeloplasty.

PURPOSE

To report on the long-term follow-up of children after laparoscopic transposition of LPCV.

METHODS

A retrospective analysis of 70 children consecutively treated by laparoscopic transposition of LPCV. Candidate patients were selected on the basis of clinical history, renal ultrasound (US), and pre-operative mercaptoacetyltriglycine (MAG-3) scan. Selection criteria included: presence of LPCV with SFU Grade 1-2 hydronephrosis, impaired drainage on MAG-3 and intraoperative normal pelviureteric junction (PUJ) and ureter peristalsis. Thinned parenchyma, impaired renal function, or history of prenatal hydronephrosis were not considered as exclusion criteria. Children were clinically followed up with US and MAG-3 scan. Success was defined by symptom resolution with improvement in hydronephrosis.

RESULTS

Seventy children, aged 8.3 years (range 2.75-16.0), were selected. Procedures were performed through transperitoneal laparoscopy (n = 42) or were robotic-assisted (n = 28). Operative time was 120 min and length of hospital stay was 2 days. The outcome was successful in 67/70 patients (96%), with a median follow-up of 52 months (range 13-114). There were three failures in children who eventually underwent dismembered pyeloplasty for a symptomatic, undiagnosed, intrinsic PUJ obstruction. Two of them had been postnatally followed for a resolving prenatally diagnosed hydronephrosis. Three children became free of symptoms, had improved hydronephrosis, but still showed impaired drainage on MAG-3 and are being closely followed up.

DISCUSSION

Although this procedure proves to have long-term efficiency in selected indications, the main challenge is to intraoperatively ascertain the absence of associated intrinsic stenosis. Objective criteria remain difficult to establish, but intraoperative findings, including dependent, funnel-shaped, normal-looking PUJ with decreasing hydronephrosis after pelvis and LPCV mobilisation, and efficient peristalsis across the PUJ under intraoperative diuretic test, represent a low likelihood of associated intrinsic stenosis. Ipsilateral impaired renal function doesn't seem to be associated with an adverse outcome. In contrast, a prenatal history of mild or self-resolving hydronephrosis in a patient later presenting with intermittent dilatation, raises the suspicion of associated intrinsic PUJ obstruction, as it is associated with a higher risk of failure.

CONCLUSION

With a long postoperative follow-up, the robotic-assisted or laparoscopic vascular hitch procedure has been successful in treating a selected group of children with obstructive LPCV, and represents a safe and reliable alternative to standard dismembered pyeloplasty in the absence of intrinsic PUJO suspected on prenatal US.

Current radiological techniques used to evaluate unilateral partial ureteral obstruction: an experimental rabbit study

AIM

The aim of this study was to evaluate functional and prognostic benefits of Doppler ultrasonography (DU), diuretic renal scintigraphy (DRS), and magnetic resonance urography (MRU) during diagnosis and follow-up of ureteropelvic junction obstruction (UPJO) and to examine apoptosis rates caused by UPJO in an experimental rabbit model.

METHOD

Twenty-four rabbits were divided randomly into two groups. The left kidneys of 15 rabbits from the first group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death.

RESULT

The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJO-created side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO.

CONCLUSION

The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a combination of radiological techniques aiding in the management decision.

Renal function recovery after laparosocopic pyeloplasty

Introduction

To observe the renal function recovery measured by diuretic renography in short and medium follow–up of patients with transperitoneal Anderson–Hynes laparoscopic pyeloplasty.

Material and methods

We performed a retrospective review from our series of laparoscopic pyeloplasties, and we applied the following selection criteria: 1) to have at least two MAG3 diuretic renography during the follow–up, performed with a gap of 4–6 months between them; 2) to have at least one year follow–up. Fulfilling these criteria, we have selected 35 patents of 62.

Results

During follow–up, statistically significant improvement comparing with the pre–surgical value has been observed in diuretic renography in the operated kidney in all selected patients during the time of follow up in terms of: functional uptake ratio (FUR), furosemide excretion and total excretion. No statistically significant differences were found in excretion time and spontaneous excretion parameters. By dividing patients in two age groups <40 years and >40 years we found no statistically significant differences between them in relation to the improvement of the FUR.

Conclusions

Laparoscopic pyeloplasty not only corrects the UPJO, it also may recover renal function demonstrated after one year follow up with diuretic renography. Laparoscopic pyeloplasty should be procedure of choice even in those patients with poor renal function at diagnosis, whenever there are chances of recovering renal function, regardless patients age.

A novel method of evaluating ureteropelvic junction obstruction: dynamic near infrared fluorescence imaging compared to standard modalities to assess urinary obstruction in a swine model

PURPOSE

Dynamic near infrared fluorescence imaging of the urinary tract provides a promising way to diagnose ureteropelvic junction obstruction. Initial studies demonstrated the ability to visualize urine flow and peristalsis in great detail. We analyzed the efficacy of near infrared imaging in evaluating ureteropelvic junction obstruction, renal involvement and the anatomical detail provided compared to conventional imaging modalities.

MATERIALS AND METHODS

Ten swine underwent partial or complete unilateral ureteral obstruction. Groups were survived for the short or the long term. Imaging was performed with mercaptoacetyltriglycine diuretic renogram, magnetic resonance urogram, excretory urogram, ultrasound and near infrared imaging. Scoring systems for ureteropelvic junction obstruction were developed for magnetic resonance urogram and near infrared imaging. Physicians and medical students graded ureteropelvic junction obstruction based on magnetic resonance urogram and near infrared imaging results.

RESULTS

Markers of vascular and urinary dynamics were quantitatively consistent among control renal units. The same markers were abnormal in obstructed renal units with significantly different times of renal phase peak, start of pelvic phase and start of renal uptake. Such parameters were consistent with those obtained with mercaptoacetyltriglycine diuretic renography. Near infrared imaging provided live imaging of urinary flow, which was helpful in identifying the area of obstruction for surgical planning. Physicians and medical students categorized the degree of obstruction appropriately for fluorescence imaging and magnetic resonance urogram.

CONCLUSIONS

Near infrared imaging offers a feasible way to obtain live, dynamic images of urine flow and ureteral peristalsis. Qualitative and quantitative parameters were comparable to those of conventional imaging. Findings support fluorescence imaging as an accurate, easy to use method of diagnosing ureteropelvic junction obstruction.

Pediatric uroradiology: state of the art

Recent years have witnessed major strides in imaging modalities, including US and contrast-enhanced voiding urosonography, fluoroscopy, CT and MRI, and these have significantly impacted paediatric uroradiology. The trend is towards reduced or no radiation exposure and combined morphological and functional imaging. This review presents the currently available and recommended modalities in modern paediatric uroradiology practice.

Further experience with the vascular hitch (laparoscopic transposition of lower pole crossing vessels): an alternate treatment for pediatric ureterovascular ureteropelvic junction obstruction

PURPOSE

Standard treatment for ureterovascular ureteropelvic junction obstruction has been dismembered pyeloplasty. We previously reported the alternative technique of laparoscopic transposition of lower pole vessels (the vascular hitch) in pediatric patients. This report is an update of this select group of pediatric patients with intermediate followup.

MATERIALS AND METHODS

Patients underwent diagnostic renal sonography and (99m)technetium-mercaptoacetyltriglycine diuretic renography with additional magnetic resonance angiography in candidate patients. Radiographic criteria included moderate hydronephrosis with no caliceal dilatation and a well preserved cortex, poor renal drainage with preserved split function and lower pole crossing vessels. Intraoperative criteria included a normal ureter and ureteropelvic junction with peristalsis. Postoperatively patients were followed clinically, and with renal sonography and (99m)technetium-mercaptoacetyltriglycine renography at 1 and 2 months, respectively. Success was defined as symptom resolution with radiographic improvement in hydronephrosis and drainage with preserved renal function.

RESULTS

Nine boys and 11 girls 7 to 16 years old (mean age 12.5) underwent laparoscopic transposition of crossing vessels, including 3 with da Vinci robot assistance. Mean operative time was 90 minutes (range 47 to 140). Median hospital stay was 24 hours. No ureteral stents or urethral catheters were placed intraoperatively. At a mean followup of 22 months (range 12 to 42) 19 of 20 patients (95%) had been successfully treated. One patient who had recurrent pain underwent successful laparoscopic pyeloplasty.

CONCLUSIONS

At intermediate followup the laparoscopic vascular hitch procedure has been successful in treating patients with ureterovascular ureteropelvic junction obstruction. In these select patients this technique offers a feasible and durable alternative to standard dismembered pyeloplasty. Ongoing evaluation continues to ensure that the promising results endure.