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Journal of Pediatric Urology (2015) xx, 1.e1e1.e7

Long-term results with the laparoscopic transposition of renal lower pole crossing vessels T. Villemagne a,b, L. Fourcade c, C. Camby a, C. Szwarc c, H. Lardy c, M.-D. Leclair a

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Paediatric Surgery and Urology Department, Ho ˆpital Me `reEnfant, Nantes University Hospital, F-44093, Nantes, France b

Paediatric Surgery Department, Ho ˆpital de la Me `re et de L’enfant, Limoges University Hospital, F-86000, Limoges, France c

Paediatric Surgery Department, Ho ˆpital Gatien de Clocheville, Tours University Hospital, F-37000, Tours, France Correspondence to: M.-D. Leclair, Paediatric Surgery and Urology Department, Ho ˆpital Me `reEnfant, Nantes University Hospital, F-44093, Nantes, France, Tel.: þ33 677 16 87 88; fax: þ33 240 08 35 46 thierry.villemagne@ gmail.com (T. Villemagne) laurent.fourcade@ chu-limoges.fr (L. Fourcade) [email protected] (C. Camby) [email protected] (C. Szwarc) [email protected] (H. Lardy) [email protected] (M.-D. Leclair) Keywords Laparoscopy; Hydronephrosis; PUJ obstruction; Fetal urology; Crossing vessels Received 25 November 2014 Accepted 25 April 2015 Available online xxx

Summary 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 preoperative mercaptoacetyltriglycine (MAG-3) scan. Selection criteria included: presence of LPCV with SFU Grade 1e2 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 2.75e16.0), were selected. Procedures were performed through transperitoneal laparoscopy (n Z 42) or were roboticassisted (n Z 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 13e114). 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 roboticassisted 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.

Table Laparoscopic Transposition of Lowerpole crossing vessels Patients Age at surgery (years) Male/female Pre-natal history of hydronephrosis Pre-operative US pelvis AP diameter (mm) Pre-operative Mag-3 impaired ipsilateral function (45%) Laparoscopic/robotic-assisted procedure Duration of procedure (minutes) Follow-up (months) Complications Clavien IIIb (failure) Clavien IIIb (urinoma) Clavien I Success

70 8.3 [2.75e16] 44/26 9 (13%) 33 [16e60]

32 (46%) 42/28 120 [60e280] 52 [13e114] 3 1 2 67 (96%)

http://dx.doi.org/10.1016/j.jpurol.2015.04.023 1477-5131/ª 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Please cite this article in press as: Villemagne T, et al., Long-term results with the laparoscopic transposition of renal lower pole crossing vessels, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.04.023

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Introduction Pelviureteric junction obstruction (PUJO) is a functional impairment of urinary transport from the renal pelvis to the ureter. It represents a heterogeneous condition with variable aetiologies combining intrinsic and/or extrinsic causes of obstruction. The impediment of the urine flow may be caused by either a short and narrowed stenotic segment of the ureter at the pelviureteric junction (PUJ), or a hypoplastic and adynamic ureteral segment of normal calibre. Extrinsic obstruction usually refers to the presence of aberrant lower pole crossing vessels (LPCV), fibrous band adhesions, or kinks in a normal-calibre PUJ [1]. The gold standard surgical technique for PUJO is the dismembered pyeloplasty, as described by Anderson and Hynes [2], which can be either open, laparoscopic or robot-assisted. The vascular relocation of LPCV (vascular hitch), which was initially described in 1951 by Hellstro ¨m et al. [3], is an attractive alternative to the dismembered pyeloplasty in the presence of LPCV without intrinsic obstruction. This procedure, which is easily performed laparoscopically, obviates to open the collecting system and eliminates the need for drainage and ureteral stenting, and has been shown to be safe, feasible and reliable in a very selected population of children with short followup [4]. It was hypothesised that the initial good results of laparoscopic transposition of LPCV in children presenting with pure extrinsic PUJO were sustained in the long term.

Patients and methods From 2005 to 2012, children older than 3 years, with hydronephrotic kidney related to PUJO and who were selected for surgical intervention at three university paediatric institutions underwent either transperitoneal laparoscopic dismembered Anderson-Hynes pyeloplasty, or laparoscopic transposition of LPCV in cases of hydronephrosis SFU grade I/II and presence of crossing vessels being deemed as the sole aetiology of obstruction. The medical records of the 70 children consecutively treated by transposition of LPCV were retrospectively reviewed. All patients referred for PUJO symptoms underwent standard pre-operative imaging procedures, including: renal ultrasonography (US) (Fig. 1) and mercaptoacetyltriglycine (MAG-3) diuretic renography. All procedures were transperitoneally performed by senior surgeons trained in minimally invasive surgery, after informed consent had been obtained for both techniques. The two procedures were transposition of LPCV or, in the event of an intrinsic obstruction being suspected intraoperatively, a dismembered pyeloplasty. The technique for the laparoscopic vascular hitch has previously been described [5]. The patient was placed in a lateral modified position and a laparoscopic transperitoneal approach was performed via a standard threeport technique (5 mm or 10 mm laparoscope in the umbilicus, and two 5 mm working ports), or using 8 mm working trocars in the robotic-assisted cases. Exposure of

T. Villemagne et al. the Gerota’s fascia and the renal pelvis was obtained either after mobilisation of the colonic flexure, or directly through the mesocolon (left side: five cases). Dissection of the LPCV and the anterior aspect of the renal pelvis should allow complete freedom of movement of the pelvis underneath the crossing vessels. Standardised intraoperative IV fluid administration included lactated Ringer (Dextrose 1.2%) at basic maintenance rate with starving deficit compensation. This was in addition to a bolus of 20 ml/kg at the beginning of pelvic dissection, and furosemide 0.5 mg/kg injection at the end of mobilisation, as described by Pesce et al., to stimulate peristalsis and challenge drainage across the PUJ [6]. Once the mobilisation was completed, the PUJ was carefully inspected for any intrinsic abnormality that may have caused the obstruction. Intraoperative criteria for performing a vascular hitch procedure included: a normal-appearance, funnel-shaped dependent PUJ without any apparent or stenotic segment, a normal calibre ureter, decrease of pelvic dilatation at the end of mobilisation (when present prior to dissection), and good peristalsis across the PUJ during the furosemide challenge test without re-increase of hydronephrosis. If no suspicion of associated intrinsic obstruction was raised, the renal pelvis was caudally mobilised to allow cephalad stabilisation of the LPCV in a groove on the anterior wall of the renal pelvis, away from the PUJ, using absorbable sutures (4/0 or 5/0 Polydiaxonone). The operating time included docking time for robotic-assisted procedures. Postoperative follow-up included clinical assessment and renal US at 1, 6, 12 and 24 months, and every 2 years. A postoperative MAG-3 renal scan was performed 1 year after surgery in all cases with pre-operative functional impairment, and was optional in other patients. Functional impairment was defined as split function