Laparoscopic transposition of lower pole vessels--the 'vascular hitch': an alternative to dismembered pyeloplasty for pelvi-ureteric junction obstruction in children

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.

Radiological and surgical correlation of pelviureteric junction obstruction in positional anomalies of the kidney in children

Pelviureteric junction obstruction, also known as ureteropelvic junction obstruction, is a congenital narrowing of the urinary excretory tract at the junction between the renal pelvis and the ureter and is a common cause of congenital pelvicalyceal dilatation. The outcome is variable, from spontaneous resolution to renal parenchymal function loss in cases of untreated high-grade obstruction. Abnormalities in renal ascent, rotation and vascularity can be associated with pelviureteric junction obstruction and easily overlooked radiologically. In this pictorial review, we explore the anatomical, radiological and surgical correlations of pelviureteric junction obstruction in the context of a normal kidney and a spectrum of renal abnormalities, including hyper-rotation (also known as renal malrotation), failed renal ascent, fusion anomalies and accessory crossing renal vessels. For each scenario, we provide technical tips on how to identify the altered anatomy at the first ultrasound assessment and correlation with scintigraphic, cross-sectional and postoperative imaging where appropriate. A detailed ultrasound protocol specifically to assess and characterise pelviureteric junction obstruction in paediatric patients is also offered.

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

INTRODUCTION

Vascular hitch (VH) gained an increasing success in treating ureteropelvic junction obstruction (UPJO) by crossing vessels (CV) in pediatrics.

AIMS OF THE STUDY

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.

METHODS

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.

RESULTS

Systematic review - Of 2783 titles/abstracts screened, 43 full-text articles were analyzed. Twelve studies on laparoscopic VH (298 pts) reported 98.3% success rate, with 1.3% intra-operative complications. Meta-Analysis - Five studies compared laparoscopic VH versus laparoscopic DP (277 pts). Operative time was reduced in VH (102.5 ± 47.5min) compared to DP (165.7 ± 53.7min; p < 0.00001). Complications were similar (VH 4/119 pts, 3.4 ± 1.2% versus DP 15/158 pts, 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 115/118 pts, 97.5 ± 1.6% versus DP 157/158 pts, 99.4 ± 0.5%; p = ns). Two prospective studies compared robot-assisted VH to laparoscopic VH (53 pts). No differences were found among complications (robot-assisted VH 0/13 pts, 0% versus laparoscopic VH 1/40 pts, 2.5%; p = ns) and success rate (robot-assisted VH 13/13 pts, 100% versus laparoscopic VH 39/40 pts, 97.5%; p = ns).

DISCUSSION

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.

CONCLUSIONS

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

OBJECTIVE

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 AND METHODS

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).

RESULTS

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.

CONCLUSIONS

A VH, for well-selected patients with CV without concomitant intrinsic obstruction, offers a high success rate with shorter operative times.

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.

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.

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

AIM

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 presente 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.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

Intraoperative inspection of the ureteropelvic junction during pyeloplasty is not sufficient to distinguish between extrinsic and intrinsic causes of obstruction: Correlation with histological analysis

INTRODUCTION

Based on current knowledge, it is possible to have an initial diagnosis of intrinsic or extrinsic ureteropelvic junction obstruction (UPJO) based solely on clinical and imaging findings. However, it may not be possible to strictly discriminate an intrinsic case with an additional extrinsic component from a primarily intrinsic stenosis because of lower pole aberrant vessels. These two disorders may coexist or trigger each other. Herein, we aimed to compare the histological changes observed in intrinsic and extrinsic types of UPJO. Our hypothesis is that inspecting the UPJ during pyeloplasty may not be a sufficient way to delineate the underlying cause of obstruction in every individual.

MATERIAL AND METHODS

We retrospectively reviewed the data of 56 patients who had dismembered pyeloplasty. The intrinsic and extrinsic groups consisted of 38 and 18 patients, respectively. Masson's trichrome stain, CD117, and connexin 43 (Cx43) antibody were used in histopathology and immunochemistry. Statistical calculations were done with chi-square and Mann-Whitney U tests.

DISCUSSION

Connexin 43 staining pattern, CD117 positive cell count, and the extent of fibrosis did not differ significantly between extrinsic and intrinsic cases. However, the difference with regard to the degree of muscular hypertrophy was close to statistical significance. The exact pathophysiological mechanism underlying UPJO has yet to be elucidated. A study directly comparing both groups histologically is indeed rare. Our study showed that there are no significant differences between the intrinsic and extrinsic groups in terms of the pacemaker activity, gap junctional communication, and extent of fibrosis. Muscular hypertrophy, which was marginally higher in our extrinsic group, may persist despite successful relocation of the obstructing vessel. The main drawbacks of our study are; the absence of a control group and the retrospective study design with its inherent selection biases.

CONCLUSIONS

Immunohistochemical profiles of intrinsic and extrinsic UPJOs resemble each other. Intraoperative inspection of the UPJ may not be enough for accurate discrimination for a surgical procedure that can correct only the extrinsic cause.

Ureteropelvic junction obstruction in children by polar vessels. Is laparoscopic vascular hitching procedure a good solution? Single center experience on 35 consecutive patients

PURPOSE

We report the results of laparoscopic vascular hitching (LVH) in a series of children with ureteropelvic junction obstruction (UPJO) owing to aberrant lower polar crossing vessels (CV). Our aim is to confirm if LVH associated with intraoperative diuretic test (DT) represents a good procedure to treat extrinsic-UPJO by CV. In order to confirm the relief of the obstruction we suggest performing an intraoperative DT.

MATERIALS AND METHODS

In our department from 2006 to 2014, 120 patients were treated for both extrinsic and intrinsic-UPJO. 85 (30 females, 55 males) presented an intrinsic obstruction and underwent dismembered pyeloplasty (AHDP), 61 open, 16 laparoscopic, 8 retroperitoneoscopic. 35 (23 males, 12 females) were studied for a suspected extrinsic-UPJO: 30 were treated with LVH (modified Hellström vascular hitch). Intraoperative-DT was performed in all patients before and after vessel transpositions confirming the UPJO and eventual relief after the procedure. We included in the study only patients with suspicion of vascular extrinsic-UPJO. Average age at surgery was 7.5years. Symptoms of presentation were recurrent abdominal/flank pain and hematuria. All patients presented ultrasound (US) detection of hydronephrosis. Preoperative diagnostic studies include: US/doppler scan, MAG3 renogram, urography, functional magnetic resonance urography (fMRU) and CT scan.

RESULTS

28 out 35 patients had a correct preoperative diagnosis, and the remaining needed an intraoperative diagnosis confirmation. All 35 patients had an intraoperative-DT: 30 patients underwent LVH (positive-DT); 3 patients (negative-DT) underwent laparoscopic-AHDP for intrinsic-UPJO; two with positive-DT and nonobstructive CV, had no surgical treatment. Median operating time was 95min; mean hospital stay was 4days. At 12-84months follow-up 29 patients remained symptoms-free, one needed after two years a laparoscopic-AHDP.

CONCLUSIONS

According our experience, LVH associated with intraoperative-DT may be considered a safe procedure to treat extrinsic-UPJO by CV in carefully selected patients. In particular, the very low incidence of relapse suggest that in suspicion of extrinsic-UPJO, performing intraoperative-DT after CV transposition allows to exclude intrinsic-UPJO confirming that the LVH-procedure has relieved the pelvic obstruction, precluding the need for AHDP.

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.

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

PURPOSE

In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO); extrinsic UPJO are rare and often due to crossing vessels (CVs).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Ureteropelvic Junction Obstruction by a Long Intraluminal Polyp and a Concurrent Crossing Vein in a Symptomatic 8-Year-old Child

Ureteropelvic junction obstruction due to intrinsic causes is often diagnosed antenatally during routine ultrasonography. Cases of extrinsic obstruction often present later and symptomatically, during childhood. We describe the rare case of an 8-year-old boy with a 2-day history of severe left flank pain, no fevers, and Society of Fetal Urology grade 3 hydronephrosis on ultrasonography. Laparoscopic dismembered pyeloplasty revealed a left ureteropelvic junction obstruction secondary to a large fibroepithelial polyp in the proximal ureter with a concomitant anterior crossing vein. We also provide a focused review of the pertinent published literature.

Hydronephrosis: Comparison of extrinsic vessel versus intrinsic ureteropelvic junction obstruction groups and a plea against the vascular hitch procedure

INTRODUCTION

Pediatric ureteropelvic junction obstruction (UPJO) due to an extrinsic crossing vessel (CV) is rare and often remains undiagnosed preoperatively. Vascular hitch procedures are often performed as associated intrinsic obstruction is not expected. We compared data and intravenous urography (IVU) findings of patients with aberrant CV versus those with intrinsic UPJO, all undergoing open dismembered pyeloplasty.

PRIMARY OBJECTIVE

Is accurate pre-operative diagnosis of aberrant CV causing extrinsic UPJO possible?

SECONDARY OBJECTIVE

To assess differences in the demographic, clinical, radiological, intra-operative features and postoperative improvement after pyeloplasty between patients with a CV and those with only intrinsic UPJO.

PATIENTS AND METHODS

Prospective study of all children below 12 years with UPJO presenting to a tertiary referral centre and who underwent open Anderson - Hynes dismembered pyeloplasty between 2003 and 2013 was conducted. Pre-operative investigations included serial ultrasonography, renal dynamic [ethylene di-cysteine (EC)] scan and IVU. These were repeated 3 months after pyeloplasty. Pre-operative IVUs of children with CV were compared with the IVUs of an equal number of similar aged children, randomly selected from the intrinsic obstruction group.

RESULTS

Pyeloplasty was performed in 643 children during the study period. Data of 33 children with aberrant CVs (mean age 6.99 years) were compared with the remaining 610 children (mean age 3.27 years) with only intrinsic obstruction. Highly significant associations of those with CV included age above 2 years, female gender, associated anomalies, abdominal pain in those above 2 years and poor preoperative function on IVU. Specific IVU features which were statistically highly significant in favor of presence of CV were small, intrarenal and globular flat bottomed pelvis. (Figure) Calyceal dilatation was also more prominent in the CV group. A funnel shaped, extrarenal pelvis was highly significant in favor of intrinsic obstruction. There was associated intrinsic obstruction in addition to CV obstruction in 8 children. All children symptomatically improved after pyeloplasty and did well on long term follow up. The majority showed improvement or stabilization of function on EC scan.

DISCUSSION

With the advent of antenatal ultrasonography, most children with UPJO are detected early. Children with CV tend to present later. This is often detected during surgery. Color Doppler is useful but is operator dependant and not performed routinely. In this study, IVU showed the presence of obstruction and loss of function unlike color Doppler, but also revealed specific diagnostic features not previously reported in literature. This can help in accurate preoperative prediction and avoid endopyelotomy, or a dorsal lumbotomy/retroperitoneal approach. Renal function in CVs is expected to be good as the obstruction is thought to be intermittent. However, we noted delayed contrast uptake on IVU in 60.6% and differential renal function on EC scan below 40% in 17 patients (56.6%). These indicate the effect of the obstruction on the renal parenchyma and the importance of early detection. Higher association with other anomalies and higher incidence in females has also not been emphasized in the literature so far. We noted associated intrinsic obstruction in 24.24% patients which is highly significant. This category of patients is likely to be missed and inappropriately treated if a "vascular hitch procedure" is performed. None of our patients had postoperative complications.

CONCLUSIONS

Characteristic features were seen on IVU helping in preoperative diagnosis which can be extrapolated to magnetic resonance urography. There is a higher association of CV in age above 2 years, females, associated congenital anomalies, delayed uptake on IVU and differential renal function below 40% compared to intrinsic obstruction. Associated intrinsic obstruction in 24% with no postoperative complications indicates the superiority of dismembered pyeloplasty over vasculopexy procedures.

Lower pole vessels in children with pelviureteric junction obstruction: laparoscopic vascular hitch or dismembered pyeloplasty?

OBJECTIVE

To choose between laparoscopic "vascular hitch" (VH) and dismembered pyeloplasty (DP) in treatment of aberrant lower pole crossing vessels potentially responsible for pelviureteric junction obstruction (PUJO) in older children.

PATIENTS AND METHODS

Retrospective study of 19 patients treated laparoscopically for PUJO. Based on videos of the procedures, we studied the anatomical relationship between the renal pelvis, the pelviureteric junction, and the aberrant vessels.

RESULTS

Eight patients had laparoscopic VH and 11 had DP. All patients with DP needed drainage. In the VH group, 7/8 patients were asymptomatic and had decreased pelvic dilation. Half of them accepted MAG3 scintigraphy, and in these patients the obstructive syndrome disappeared completely. The last patient in this group was lost to follow-up. We observed three anatomical variations in the location of polar vessels: type 1 (in front of the dilated pelvis), type 2 (in front of the pelviureteric junction), type 3 (under the pelviureteric junction, resulting in ureteral kinking).

CONCLUSION

Laparoscopic VH is a simple technique involving no urinary anastomosis or drainage, but we cannot guarantee that the crossing vessels are the sole etiology for PUJO. Following our experience, only patients with type 3 anatomical variations and with a normal pelviureteric junction should be proposed for VH.

Retroperitonoscopic pyelopexy for pelviureteral junction obstruction with crossing vessel in adolescents: Hellstrom principle revisited

OBJECTIVE

To present our new approach using a minimally invasive technique for the management of pelviureteral junction (PUJ) obstruction with a crossing vessel.

MATERIALS AND METHODS

In December 2009 to December 2011, out of 23 cases of retroperitoneoscopic laparoscopic pyeloplasty, four adolescents presenting with PUJ obstruction due to an aberrant crossing vessel, with intermittent attacks of renal colic and mild dilatation of the renal pelvis and calyces, were operated by retroperitoneoscopic pyelopexy. A retroperitoneoscopic approach was used in all patients using three trocars. After dissection of the PUJ from the anterior crossing vessel, and ensuring good funneling of the PUJ that proved to show mild dilatation, an interrupted 3/0 polyglycolic suture was used to fix the renal pelvis to the psoas muscle away from the crossing vessel (pyelopexy). A retrograde DJ stent was placed at the end of the procedure.

RESULTS

The four patients had a mean age of 18.25 years (16-20): 2 males and 2 females, two right sided and two left sided. Average operative time was 46 min (40-55). All patients were discharged on the same day. No intraoperative complications were encountered. The DJ stent was removed 6 weeks postoperatively. After a mean follow up of 2.125 years (6 months-3 years) no recurrences were observed.

CONCLUSION

Retroperitoneoscopic pyelopexy is shown to be a reliable, effective, safe and minimally invasive technique for the management of PUJ obstruction with a crossing vessel in selected cases. Long-term follow up is needed to assess any recurrence or development of complications.

Robot-assisted and laparoscopic repair of ureteropelvic junction obstruction: a systematic review and meta-analysis

CONTEXT

Over the last two decades, minimally invasive treatment options for ureteropelvic junction obstruction (UPJO) have been developed and popularized.

OBJECTIVE

To critically analyze the current status of laparoscopic and robotic repair of UPJO.

EVIDENCE ACQUISITION

A systematic literature review was performed in November 2012 using PubMed. Article selection proceeded according to the search strategy based on Preferred Reporting Items for Systematic Reviews and Meta-analyses criteria.

EVIDENCE SYNTHESIS

Multiple series of laparoscopic pyeloplasty have demonstrated high success rates and low perioperative morbidity in pediatric and adult populations, with both the transperitoneal and retroperitoneal approaches. Data on pediatric robot-assisted pyeloplasty are increasingly becoming available. A larger number of cases have also been reported for adult patients, confirming that robotic pyeloplasty represents a viable option for either primary or secondary repair. Robot-assisted redo pyeloplasty has been mostly described in the pediatric population. Different technical variations have been implemented with the aim of tailoring the procedure to each specific case. The type of stenting, retrograde versus antegrade, continues to be debated. Internal-external stenting as well as a stentless approach have been used, especially in the pediatric population. Comparative studies demonstrate similar success and complication rates between minimally invasive and open pyeloplasty in both the adult and pediatric setting. A clear advantage in terms of hospital stay for minimally invasive over open pyeloplasty was observed only in the adult population.

CONCLUSIONS

Laparoscopy represents an efficient and effective less invasive alternative to open pyeloplasty. Robotic pyeloplasty is likely to emerge as the new minimally invasive standard of care whenever robotic technology is available because its precise suturing and shorter learning curve represent unique attractive features. For both laparoscopy and robotics, the technique can be tailored to the specific case according to intraoperative findings and personal surgical experience.

Histologic differences between extrinsic and intrinsic ureteropelvic junction obstruction

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

Identification of a significant CV intraoperatively does translate to a discernible appearance histologically.

Pelvi-ureteric junction obstruction with crossing renal vessels: a case report of failed laparoscopic vascular hitch

INTRODUCTION

Dismembered pyeloplasty has been the traditional technique in the management of pelvi-ureteric junction obstruction (PUJO) secondary to crossing renal vessels in children. Laparoscopic transposition of lower pole vessels for PUJO has been described in children as well as adults.

CASE REPORT

We report a child with PUJO secondary to lower pole renal vessels who underwent laparoscopic transposition of vessels. The child had persistent PUJO, which was later treated with laparoscopic dismembered pyeloplasty.

CONCLUSION

Laparoscopic transposition of renal vessels is a simple technique, and requires less operating time. It involves no anastomosis or insertion of temporary DJ stent. However, as of now there are no imaging techniques or intraoperative procedures available to confirm that the crossing renal vessels are the sole etiology for PUJO. This option should therefore be used with caution.

Laparoscopic pyeloplasty for repair of pelvi-ureteric junction obstruction in children

PURPOSE

To report our initial experience with laparoscopic pyeloplasty (LP) in children with pelvi-ureteric junction (PUJ) obstruction, and to describe the evolution and evaluate the results for these patients.

MATERIALS AND METHODS

Between May 2005 and April 2008, we retrospectively reviewed the records of 28 consecutive infants and children (20 males, eight females; mean age 63 months, range 2-180 months) with unilateral PUJ obstruction, some with deterioration of renal function on isotope renography. They all underwent LP (18 on the right, 10 on the left). The patient was placed in a (3/4) lateral position with three ports. The PUJ was resected and the anastomosis made using absorbable sutures. A JJ stent was inserted by laparoscopy in the majority of patients. Follow-up included clinical and ultrasound assessment, and isotope renography at 6 months.

RESULTS

LP was feasible in 26 of 28 patients (93%). The procedure could not be completed by laparoscopy in two patients, the main reason being difficulty in completing the anastomosis. Stent insertion was successful in 25 of the remaining 26 cases. In the one unsuccessful case, a perianastomotic drain was placed without complication in the postoperative period. An aberrant crossing vessel was found in four patients. In two we held up the aberrant crossing vessel and PUJ by 2-3 non-absorbable sutures without tension, and without the need for pyeloplasty. In the other two cases we performed an LP-enabled ureteric transposition. There were three postoperative complications: pyelonephritis in two patients and one patient required operative intervention for PUJ leakage, and underwent a nephrostomy with a further uneventful course. The mean operative time was 145 min (range 70-270 min), and mean hospital stay was 4 (1-8) days. In one patient the JJ time of removal by cystoscopy, and ureteroscopy was used to retrieve it. Mean follow-up was 18 months (range 4-64 months). The 26 patients who underwent LP were asymptomatic after removal of the double JJ stent, showing reduction of the degree of hydronephrosis in all patients, and had also improved PUJ drainage on isotope renography or sonography.

CONCLUSIONS

LP is effective and safe in children with minimal morbidity and gives excellent short-term results. The feasibility is also excellent in patients younger than 1 year. The transabdominal approach revealed good exposition without disadvantage to the patient. However, the LP is more difficult and the operative time remains longer than open pyeloplasty.

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.