Laparoscopic transposition of lower pole crossing vessels ('vascular hitch') in pure extrinsic pelvi-ureteric junction (PUJ) obstruction in children

Laparoscopic Vascular Hitch for Polar Vessels in Pyeloureteric Junction Obstruction: Medium-Term Follow-up of a Monocentric Experience

INTRODUCTION

 To evaluate medium-term results of the management of patients with pyeloureteric junction obstruction (PUJO) secondary to lower pole vessels managed by a laparoscopic vascular hitch technique.

MATERIALS AND METHODS

 We performed a retrospective monocentric study of all patients who were operated using this technique, transperitoneal laparoscopy (TL) or robotic surgery (RS), from 2011 to 2018. Description of the initial population, pre- and postoperative data was collected and analyzed.

RESULTS

 During the study period, 25 patients (11 males and 14 females) with a mean age of 11.1 years were managed. Initial symptoms leading to the diagnosis were present in 21 children (lumbar pain 17, high blood pressure 1, and infection 3). Four patients were diagnosed incidentally (three) or following a prenatal screening (one). The diagnostic has been confirmed in all patients by ultrasound scan completed by computed tomography or magnetic resonance imaging scans. Twenty-one patients were operated by TL and four by RS. Mean operating time was 90.2 minutes. Three immediate postoperative complications were noticed including one urinary tract infection, one urinary tract rupture, and one postoperative massive dilatation. After a mean follow-up of 3 1.5 years, 17 patients remain asymptomatic. Mean pelvic diameter was preoperatively 35 mm and postoperatively 10.5 mm (p < 0.005). Of the eight remaining patients, six required reoperation (pyeloplasty) and two remained symptomatic with recurrent flank pain.

CONCLUSION

 In our experience, PUJO managed by the vascular hitch technique is associated with a 68% success rate after a 3-year follow-up. These results are different from the current literature which reported success rate of 96% after 52 months. It leads us to question the efficiency of this technique in the long term in our hands both concerning the indications and the surgical procedure itself. Further studies are required to collect data concerning the evolution of our patients during adulthood to compare their evolution to classic pyeloplasty.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

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.

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.

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.

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.

Laparoscopic transposition of lower-pole crossing vessels: Long-term follow-up of 33 patients at puberty

PURPOSE

Laparoscopic transposition of lower-pole crossing vessels (LPCV) has been described as an effective alternative to dismembered pyeloplasty in selected indications of hydronephrosis, with purely extrinsic vascular PUJ obstruction. We hypothesized that the initial good results of laparoscopic transposition of LPCV in children presenting with pure extrinsic PUJO were sustained at puberty when these children go through statural growth, without inducing significant changes in systemic arterial blood pressure. Hence, we analysed the long-term follow-up of adolescents successfully treated with this technique during childhood, reviewed after they have reached puberty, focusing on the incidence of recurrent symptoms, renal dilatation, and systemic hypertension.

PATIENTS AND METHODS

Early 2015, among a cohort of 70 patients prospectively followed-up since they had undergone laparoscopic transposition of LPCV during childhood (2005-2012), we performed systematic clinical assessment of the 33 adolescent patients (16 years; range 12-22) who had reached puberty age. Assessment focused on clinical examination, arterial blood pressure measurements, and renal ultrasonography (Table).

RESULTS

The median delay since surgery was 67 months (31-113 months). Arterial blood pressure adjusted for age and height was within normal range in all patients. Three patients had occasional episodes of abdominal pain: two of them had normal US (including during pain episodes), one had persistent extra-renal dilated pelvis with no calyceal dilatation. None of them showed obvious clinical characteristics linking the pain to a renal origin. Renal US showed residual SFU grade 2 pelvicalyceal dilatation in 2/33 asymptomatic patients; SFU grade 1 extra-renal pelvis dilatation in 3, and was normal in the remaining. When Doppler analysis was performed, there was no evidence of lower-pole parenchyma perfusion defect.

DISCUSSION

In adolescents successfully treated during childhood with transposition of LPCV, there seemed to be no impact of this procedure on systemic arterial blood pressure in adolescents after puberty, nor any evidence of late recurrence of symptoms or hydronephrosis. The main limitation of the present study relies in its retrospective nature, the limited sample size, and the obvious difficulty in adequate selection of candidate patients to this technique. The present experience however reinforces the hypothesis that a vast majority of children can be definitely cured with transposition of LPCV when they represent the sole aetiology of obstruction.

CONCLUSION

In the long-term follow-up, most adolescents successfully treated during childhood by laparoscopic transposition of LCPV for PUJ extrinsic obstruction remain asymptomatic, with normal arterial blood pressure, and normal renal ultrasound when they reach puberty.

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.

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.

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.