Crossing Vessels Research Articles

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

BackgroundTo analyze the clinical characteristics of ureteropelvic junction obstruction (UPJO) caused by crossing vessels (CV) in infants and young children. MethodsA 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. ResultsA 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. ConclusionsThe 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 EvidenceIII.

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.

Laparoscopic transposition for crossing vessels (vascular hitch) in pure extrinsic pelvic-ureteric junction obstruction: a successful case report of a 2-year-old infant with horseshoe kidney

BackgroundPediatric hydronephrosis induced by pelvic-ureteric junction obstruction (PUJO) is treated by dismembered pyeloplasty (DP) via open and laparoscopic surgery. The etiology of PUJO involves both intrinsic stenosis and extrinsic compression of crossing vessels (CVs). PUJO owing to CVs is also treated by DP, as there is no consensus concerning this vascular condition. We encountered a 2-year-old infant with pure extrinsic PUJO combined with horseshoe kidney who successfully underwent laparoscopic transposition for CVs (vascular hitch).Case presentationA 2-year-old boy was prenatally diagnosed with left multicystic dysplastic kidney (MDCK) and right hydronephrosis and received a definitive diagnosis after birth. At 6 months old, renal scintigraphy revealed a non-functioning pattern in the left kidney and an obstructive pattern in the right, showing no response to furosemide loading. The patient also had recurrent urinary tract infection, and his right hydronephrosis gradually worsened. We decided to perform surgery for the right PUJO. Preoperative enhanced computed tomography detected three right renal vessels independently branching from the abdominal aorta. The middle renal vessels were located at the ventral side of the pelvis and coincident with the site of PUJO. These vessels were suspected of being CVs. The patient underwent laparoscopic surgery electively. A 5-mm trocar was inserted at the umbilicus for a 5-mm, 30° rigid scope. Two additional ports were then inserted under laparoscope inspection. The dilated right pelvis and CVs were detected after ascending colon mobilization. To confirm the pathogenesis of PUJO, the CVs were dissected and taped. After taping the CVs, an intraoperative diuretic test was performed using furosemide loading. Peristalsis of the right ureter was recognized, and the extrinsic PUJO owing to the CVs was definitively confirmed. We therefore performed transposition for the CVs (vascular hitch procedure). The CVs were mobilized in the cranial direction and those were wrapped by dilated pelvis. The post-operative course was uneventful. The renal scintigraphy findings improved and showed a favorable response of furosemide loading.ConclusionsThe laparoscopic vascular hitch procedure is minimally invasive and effective for extrinsic PUJO due to CVs. Anastomotic stricture after Anderson and Hynes DP can be prevented by appropriate patient selection.

Minimally invasive vascular hitch to treat pediatric extrinsic ureteropelvic junction obstruction by crossing polar vessels: A systematic review and meta-analysis

Vascular hitch (VH) gained an increasing success in treating ureteropelvic junction obstruction (UPJO) by crossing vessels (CV) in pediatrics. We aimed: (i) to compare laparoscopic VH versus laparoscopic dismembered pyeloplasty (DP) to treat UPJO by CV; (ii) to review possible amelioration given by a robot-assisted procedure. Using defined search strategy, three investigators identified all studies on laparoscopic VH. Those studies comparing VH versus DP or versus robot-assisted VH were included in the meta-analysis. The meta-analysis was conducted using RevMan 5.3. Data are mean±SD. Systematic review - Of 2783 titles/abstracts screened, 43 full-text articles were analyzed. Twelve studies on laparoscopic VH (298pts) reported 98.3% success rate, with 1.3% intra-operative complications. Meta-Analysis - Five studies compared laparoscopic VH versus laparoscopic DP (277pts). Operative time was reduced in VH (102.5±47.5min) compared to DP (165.7±53.7min; p<0.00001). Complications were similar (VH 4/119pts, 3.4±1.2% versus DP 15/158pts, 9.5±6.8%; p=ns). Hospital stay was shortened in VH (1.1±0.9dd) versus DP (3.3±3.2dd; p<0.0001; Summary Figure). The success rate was comparable (VH 115/118pts, 97.5±1.6% versus DP 157/158pts, 99.4±0.5%; p=ns). Two prospective studies compared robot-assisted VH to laparoscopic VH (53pts). No differences were found among complications (robot-assisted VH 0/13pts, 0% versus laparoscopic VH 1/40pts, 2.5%; p=ns) and success rate (robot-assisted VH 13/13pts, 100% versus laparoscopic VH 39/40pts, 97.5%; p=ns). Several studies have been reported long-term results of laparoscopic VH in children. However, few papers demonstrated its superiority over laparoscopic DP to treat extrinsic UPJO. In the present study, we found similar incidence of complications and success rates when comparing VH versus DP. Nonetheless, the operative time and the length of hospital stay were significantly reduced in VH compared to DP. An increasing number of surgeons performed robotic-assisted VH, reporting promising outcomes. However, only a couple of studies compared robot-assisted VH to laparoscopic VH, with a similar incidence of complications and success rate in both procedures. The main limitations of the study were related to the slight number of papers included and to their quality, since all of them were retrospective studies or prospectively followed-up cohort of patients. Laparoscopic VH seems to be a safe and reliable procedure to treat UPJO by CV. The procedure appeared quicker than laparoscopic DP, with shortened hospital stay. Further studies are needed to corroborate these results and to establish amelioration given by a robot-assisted procedure.

Vascular hitch for paediatric pelvi-ureteric junction obstruction with crossing vessels: institutional analysis and systematic review with meta-analysis.

To compare the outcomes for laparoscopic vascular hitch (VH) and dismembered pyeloplasty in patients with pelvi-ureteric junction obstruction (PUJO) secondary to crossing vessels (CV). Patients who underwent laparoscopic management of CV at our institution were identified between 2008 and 2020. Baseline characteristics and outcome measures were compared between those who underwent VH and those who underwent dismembered pyeloplasty. Those who underwent VH were selected intraoperatively by identifying CV in the absence of intrinsic obstruction by assessing resolution of hydronephrosis after cranially displacing the CV away from the PUJ, followed by intraoperative fluid bolus and diuretic test. In addition, a systematic search and meta-analysis were performed in June 2020 (International Prospective Register of Systematic Reviews [PROSPERO] ID CRD42020195833). A total of 20 patients underwent VH and 74 dismembered pyeloplasty. On multivariate analysis, VH was associated with: shorter operative time (P = 0.001; odds ratio [OR] 0.455, 95% confidence interval [CI] 0.294-0.705) and length of stay (P = 0.012; OR 0.383, 95% CI 0.183-0.803), lower use of stents (P < 0.001; OR 0.024, 95% CI 0.004-0.141) and opioid administration (P = 0.005; OR 0.157, 95% CI 0.044-0.567). From our literature search, 194 records were identified and 18 records were included (three comparative and 16 non-comparative). Meta-analysis of the comparative studies and our institutional data showed similar success rates (relative risk [RR] 1.77, 95% CI 0.33-9.52) and complication rates (RR 0.75, 95% CI 0.20-2.82). VH was associated with shorter operative time (standardised mean difference [SMD] -1.65, 95% CI -2.58 to -0.72 h) and hospital stay (SMD -1.41, 95% CI -2.36 to -0.47 days). The VH success rates ranged from 87.5% to 100% in the identified studies. Failure of VH was associated with unrecognised concomitant intrinsic obstruction in addition to CV. A VH, for well-selected patients with CV without concomitant intrinsic obstruction, offers a high success rate with shorter operative times.

Uretero-pelvic junction obstruction with and without crossing vessels: surgical outcome in a single center experience

Uretero-pelvic junction obstruction is the most common cause of prenatal hydronephrosis. It can be intrinsic, extrinsic due to crossing vessel (CV) or mixed. This paper aims to present the surgical outcome in a single pediatric third-level center. A retrospective analysis of all children operated between 2011 and 2018 was conducted. Demographic information, pre-operative pelvic antero-posterior diameter (APD), intra-operative parameters, hospital stay and follow-up were considered. Re-do operations and success rate for Vascular Hitch (VH), open and laparoscopic pyeloplasties were recorded. 128 patients were included. The mean pre-operative APD was 30 mm. The etiology was intrinsic in 71.9%, extrinsic in 25.0% and mixed in 3.1%. The median age between intrinsic and extrinsic groups was statistically different. Thirty-one VH, 88 dismembered and 9 non-dismembered pyeloplasties were performed. The median hospital stay was 2 days for VH and 6 for pyeloplasties. The median hospital stay was statistically longer in open pyeloplasties compared to laparoscopic. The mean post-operative APD was 14 mm. The success rate after VH was 90.3%, after open pyeloplasties 97.9% and after mini-invasive pyeloplasties 91.8%. VH could be a good option in the treatment of hydronephrosis due to CV, laparoscopic pyeloplasties have equivalent success rate and shorter hospital stay than open pyeloplasties.

Histopathological study of crossing vessels an associated finding or cause in pelviureteric junction obstruction

Most common cause for pelviuretericjunction (PUJ) obstruction is thought to be intrinsic defect of muscular development or the deficient nerves in the obstructed narrow segment. Other causes include obstruction from outside: crossing vessel (CV), tumor compressing PUJ etc and intramural causes. Congenital Hydronephrosis is associated with crossing vessels in 26% of cases. The purpose of this work is to evaluate histopathological changes in patients of PUJ obstruction with or without crossing vessels. This was a prospective study conducted on 128 patients who underwent pyeloplasty from January 2016 to June 2018. Of these 42 patients had associated crossing vessels. Hisopathological analysis of PUJ segment was done to look for chronic inflammation, muscular hypertrophy, fibrosis, muscle disarray and synaptophysin. Moderate to severe chronic inflammation was seen in 23.8% and 44.2% (P &amp;#62; 0.05) cases with CV and without CV respectively, similarly fibrosis and muscular hypertrophy was seen higher in cases without CV although these were not statistical significant. On contrary muscle disarray shows trend of higher in cases with CV but it was also not statistical significant. Synaptophysin was positive in 4.8% cases with CV and 4.7% cases without CV. Based on this study there is no significant statistical difference in the histopathological changes in patients with or without crossing vessels. So crossing vessel is not the cause but an associated finding in pelvi-ureteric junction obstruction.

Management of crossing vessels in children and adults: A multi-center experience with the transperitoneal laparoscopic approach.

Crossing vessels (CVs) are common in older children and adults with hydronephrosis but no gold standard exists on how to treat this condition. The final decision is made intraoperatively by the surgeon. To assess the outcome of the laparoscopic dismembered pyeloplasty with translocation of the CVs in children and adults. Prospectively collected data from 3 departments was reviewed. Inclusion criteria were: 1) a transperitoneal laparoscopic approach; 2) dismembered pyeloplasty; and 3) the same operating pediatric urologist (RC) or urologist (TS). In the case of CVs, pyeloplasty with vessel transposition (children) or with cephalad translocation (adults) was performed. Forty-eight children and 41 adults met these criteria. Patients were divided into 4 groups: children with (group 1A) and without (group 1B) CVs, and adults with (group 2A) and without (group 2B) CVs. Any surgical reintervention at the uretero-pelvic junction (UPJ) was deemed a failure. The overall reintervention rate was 3/48 (6.25%) in children and 2/41 (4.9%) in adults (p > 0.05), and involved the following: 4 endopyelotomies and 1 redo pyeloplasty. Crossing vessels were identified in 28/48 (58%) children and 12/41 (29%) adults. The mean operation time was 152 min in group 1A and 161 min in group 2A (p > 0.5). Reintervention was needed in 2/28 patients in group 1A and in 1/12 patients in group 2A (p > 0.05). There was no difference in the failure rate between group 1A and group 1B, nor between group 2A and group 2B (p > 0.05). Crossing vessels should be meticulously looked for during pyeloplasty in older children and adults. Dismembered laparoscopic pyeloplasty (LP) with dorsal transposition or cephalad translocation are comparable methods in terms of success rate for the treatment of UPJ obstruction in these patients.

Detection rate of crossing vessels in pediatric hydronephrosis: Transperitoneal laparoscopy versus open lumbotomy.

A bundle of crossing vessels (CV) supplying the lower pole of the kidney and causing mechanical obstruction of the ureteropelvic junction (UPJ) has been the subject of many discussions. During pyeloplasty, it is possible to overlook the CV. This may result in recurrent dilatation of the kidney and the need for re-surgery. To compare the detection rate of CV in UPJ obstruction (UPJO) depending on the operational access applied (transperitoneal laparoscopy (LAP) vs open lumbotomy (OPEN)). Assessment of features that could indicate the presence of CV. Two hundred and forty-six pediatric pyeloplasties were performed between January 2006 and July 2017 in the Department of Pediatric Surgery and Urology at the Wroclaw Medical University, Poland - 111 out of them by LAP and 135 by OPEN, on 98 girls and 148 boys. A retrospective analysis of the patient records for the detection of CV and characteristics of the CV before surgery was performed. Intraoperative CV causing obstruction of the UPJ in the LAP group were recognized in 34.2% (n = 38) of the patients, and within the OPEN group in 12.5% (n = 17) (p < 0.0001); 90% (n = 27) of patients with the diagnosed CV did not show congenital hydronephrosis. In 68% (n = 21) of the patients there were cases of recurrent renal colic. The presence of CV was suspected in 7.2% of kidney ultrasounds and in 12.5% in computed tomography (CT) urograms. The detection rate of CV in UPJO is statistically higher in LAP access than in open retroperitoneal lumbotomy. The distinguishing features of patients with CV are the lack of prenatal diagnosis for hydronephrosis and the presence of pain in the lumbar region.

Hydronephrosis in Children Caused by Lower Pole Crossing Vessels-How to Choose the Proper Method of Treatment?

Objectives: Assessment of the efficacy of intraoperative diagnosis between extrinsic and intrinsic UPJO in children. Assessment of the efficacy of laparoscopic vascular-hitch procedure in UPJO caused by lower pole crossing vessels (CV).Materials and Methods: Between 2008 and 2017, 47 laparoscopic procedures were performed with the CV discovered intraoperatively. CV were translocated cephalad, and the UPJ was carefully inspected. The Chapman's vascular hitch procedure was accomplished in the case of decreasing sizes of the pelvis and clear, visible peristalsis of the UPJ (31 patients). In the other cases, Anderson–Hynes (A-H) pyeloplasty with posterior translocation of the CV was performed (16 patients).Results: The median age at operation was 6 years (range 1–16) in VH and 6 years (range 2–17) in A-H (p = 0.4635). Prenatal dilatation of kidney was diagnosed in 18.7% of VH and 10% of A-H cases (p = 0.5474). Success was achieved in 16 (100%) patients in the A-H and in 29 (93.54%) in the VH groups. Two patients (6.5%) in VH required repeated surgery because of a misdiagnosed intrinsic obstruction. Median operation time in VH was 80 min (range 40–105) and was 105 (range 70–225) in A-H (p < 0.05).Conclusions: The intraoperative selection based on intraoperative pelvis and UPJ appearance after vessel transposition is sufficient in majority of cases. Laparoscopic vascular hitch seems to be effective and safe procedure, but can only be performed on carefully selected patients. In case of misdiagnosis, reoperation is possible with the same laparoscopic access.

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

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

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. 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. 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 1.5TMR 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. 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). 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. 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.

Laparoscopic transposition of lower pole crossing vessels (vascular hitch) in children with pelviureteric junction obstruction.

Congenital hydronephrosis due to intrinsic or extrinsic uretero-pelvic-junction (UPJ) obstruction (UPJO) is a common problem in childhood UPJO may be caused by intrinsic disorganization or by extrinsic compression from crossing vessels (CV); extrinsic causes usually present symptomatically in older children. This report the large Italian experience in the treatment of children with extrinsic-UPJO by CV. We analyzed the data of 51 children (17 girls and 34 boys, median age 10, 7 years) affected by extrinsic-UPJO were treated in three Italian institutions with laparoscopic transposition of CV (Hellström Vascular Hitch modified by Chapman).The intraoperative diuretic-test was performed in all patients before and after the vessels transpositions confirming the extrinsic-UPJO. We included in the study only patients with suspicion of vascular extrinsic obstruction of the UPJ. Symptoms at presentation were recurrent abdominal/flank pain and haematuria. All patients presented intermittent ultrasound (US) detection of hydronephrosis (range, 18-100 mm). Preoperative diagnostic studies included: US/doppler scan, MAG3-renogram, functional-magnetic-resonance-urography (fMRU). Median operative time was 108 minutes; median hospital stay: 3, 4 days. Unique complications: a small abdominal wall hematoma and higher junction-translocation without obstruction. During follow-up (range, 12-96 months) all patients reported resolution of their symptoms, a decrease in the hydronephrosis grade and improved drainage on diuretic renogram. We believe that Vascular Hitch is less technically demanding than laparoscopic pyeloplasty, resulting in a lower complication rate and a significantly reduced hospitalization. The results of our study allow us to conclude that laparoscopic VH may be a safe, feasible, and attractive alternative to treat obstructed hydronephrosis due to CV presenting a useful alternative to AHDP in the management of symptomatic children where CV are deemed the sole aetiology. We recommend careful patient selection based on preoperative clinical and radiologic findings that are diagnostic of extrinsic-UPJO, combined with intraoperative-DT to confirm the appropriate selection of corrective procedure.

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

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. 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. 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. 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.

High-pressure balloon assessment of pelviureteric junction prior to laparoscopic “vascular hitch”

ABSTRACTAim To assess if calibration of the ureteropelvic junction (UPJ) using a high-pressure balloon inflated at the UPJ level in patients with suspected crossing vessels (CV) could differentiate between intrinsic and extrinsic stenosis prior to laparoscopic vascular hitch (VH).Materials and Methods We reviewed patients with UPJO diagnosed at childhood or adolescence without previous evidence of antenatal or infant hydronephrosis (10 patients). By cystoscopy, a high-pressure balloon is sited at the UPJ and the balloon inflated to 8-12 atm under radiological screening. We considered intrinsic PUJO to be present where a ‘waist’ was observed at the PUJ on inflation of the balloon and a laparoscopic dismembered pyeloplasty is performed When no ‘waist’ is observed we considered this to represent extrinsic stenosis and a laparoscopic VH was performed. Patients with absence of intrinsic PUJ stenosis documented with this method are included for the study.Results Six patients presented pure extrinsic stenosis. The mean age at presentation was 10.8 years. Mean duration of surgery was 99 min and mean hospital stay was 24 hours in all cases. We found no intraoperative or postoperative complications. All children remain symptoms free at a mean follow up of 14 months. Ultrasound and renogram improved in all cases.Conclusion When no ‘waist’ is observed we considered this to represent extrinsic stenosis and a laparoscopic VH was performed. In these patients, laparoscopic transposition of lower pole crossing vessels (‘vascular hitch’) may be a safe and reliable surgical technique.

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

In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO); extrinsic UPJO are rare and often due to crossing vessels (CVs). We retrospectively reviewed all data of children with UPJO that underwent surgery in our institution from 2004 to 2011. Analyses included age at surgery, gender, preoperative and postoperative results of ultrasound and renal scans [differential renal function (DRF); signs of obstruction], and pathology reports. Available histological specimens of cases with CV were compared to a random selection of intrinsic cases in a blinded fashion. After additional Masson's trichrome staining, the specimens were scored for fibrosis, muscular hypertrophy, and chronic inflammation. Out of 139 patients with UPJO, 39 cases were associated with CV. Median age at surgery was 68 months (range 2-194) in the CV group and 11.5 months (range 0-188) in IUPJO group. Laparoscopic dismembered pyeloplasty (LDMP) was carried out in 134 and open DMP in five patients. Preoperative ultrasound identified 28/39 cases with CV. DRF below 40 % was more frequently seen in CV patients (p = 0.020). Histological analyses revealed no differences between the CV and IUPJO specimens in total. CV patients with higher grades of muscular hypertrophy had lower preoperative DRF, compared to those with higher preoperative DRF (p = 0.026). Functional recovery after (L)DMP was excellent in both groups. We could not find any significant histological differences between CV and IUPJO in children. To obtain excellent functional recovery, surgical procedures with a definite correction of the UPJ should be preferred in paediatric patients with CV.

Histologic Differences Between Extrinsic and Intrinsic Ureteropelvic Junction Obstruction

Ureteropelvic junction obstruction (UPJ) can be caused by intrinsic disorganization or extrinsic compression from crossing vessels (CV). What is not clear is whether there is also intrinsic UPJ pathology in patients with CV. Recent surgeries, such as the Hellström vascular hitch procedure, move the CV cephalad without resecting the UPJ, which presumes no intrinsic narrowing. Our aim was to determine whether the histologic features of the 2 types of UPJ obstruction are distinct enough to enable a blinded pathologist to histologically identify the cause of obstruction. We reviewed all patients undergoing pyeloplasties from 2000 to 2006. All CV cases with available pathology were selected. A random selection of intrinsic cases was used as controls. One blinded pathologist reviewed the histology, specifically scoring muscle and collagen density. Sixteen patients were reviewed. Seven had CV and 9 had intrinsic obstruction. Muscle density was different between the 2 groups with CV denser compared with intrinsic (P = .005). The pathologist correctly assigned the cause of obstruction in 5/7 (71%) of CV and 7/9 (78%) of intrinsic cases (P = .039). Identification of a significant CV intraoperatively does translate to a discernible appearance histologically.

MISSED ANTERIOR CROSSING VESSELS DURING OPEN RETROPERITONEAL PYELOPLASTY: LAPAROSCOPIC TRANSPERITONEAL DISCOVERY AND REPAIR

Extrinsic ureteropelvic junction obstruction due to anterior crossing segmental renal vessels is present in more than 50% of patients in adulthood. In this situation the ureter must usually be dismembered and transposed anterior to the crossing vascular structures, where it is anastomosed to the renal pelvis. Via the open retroperitoneal approach there may be a limited view of the anterior surface of the ureteropelvic junction and, hence, anterior crossing vessels may possibly be missed. We describe 2 patients with ureteropelvic junction obstruction in whom anterior vessels were missed during open retroperitoneal repair. Laparoscopic transperitoneal secondary pyeloplasty with posterior displacement of the crossing renal vessel was performed in each case. Two patients presented with symptomatic congenital ureteropelvic junction obstruction after failed endopyelotomy in 1 and failed open retroperitoneal procedures in both. Preoperatively spiral computerized tomography angiography with a ureteropelvic junction protocol revealed crossing vessels in the 2 cases. This finding was confirmed at transperitoneal laparoscopic pyeloplasty. The ureter and renal pelvis were transposed anterior to the crossing vessels and 2 rows of running sutures were placed to complete the anastomosis. The 2 laparoscopic procedures were completed successfully. The anterior crossing vessels were preserved in each case. Currently the patients are asymptomatic and furosemide washout renal scan was normal. Spiral CT angiography reliably delineates the renal vascular anatomy in patients with ureteropelvic junction obstruction. This study may be valuable before planned open retroperitoneal ureteropelvic junction obstruction repair. Laparoscopic pyeloplasty may successfully manage anterior crossing vessels associated with secondary ureteropelvic junction obstruction.

The absence of crossing vessels in association with ureteropelvic junction obstruction detected by prenatal ultrasonography.

The widespread use of prenatal ultrasonography has led to a marked increase in the incidence of ureteropelvic junction obstruction presenting in infancy. Which of these prenatally detected lesions requires repair has yet to be fully determined. Attempts to characterize prenatally detected ureteropelvic junction obstruction in regard to symptomatic obstruction detected later in life may provide useful insights into the management of these incidentally discovered lesions. We evaluated the presence of crossing vessels in ureteropelvic junction obstruction identified by prenatal ultrasonography. We reviewed the records of patients who underwent dismembered pyeloplasty for primary ureteropelvic junction obstruction with specific attention to the mode of presentation and presence of crossing vessels associated with obstruction. In 30 patients with a mean age of 6 months ureteropelvic junction obstruction detected prenatally was not associated with a crossing vessel. Ureteropelvic junction obstruction was identified postnatally in 125 patients who underwent open pyeloplasty. It was detected incidentally in 8, of whom crossing vessels were present in 1 (12%). There were signs or symptoms related to ureteropelvic junction obstruction in 117 patients. In contrast to the group with prenatally detected ureteropelvic junction obstruction in which crossing vessels were never noted, crossing vessels were associated with 36 (30%) of the 120 kidneys operated on in this postnatally discovered group. No crossing vessels were present in patients with prenatally detected ureteropelvic junction obstruction compared with 30% in symptomatic patients. This finding may reflect the natural history of the disorder, or it may suggest that prenatally identified ureteropelvic junction obstruction is an entity largely different from obstruction presenting later in life.