V577: Pediatric robotic-assisted laparoscopic pyeloplasty in horseshoe kidney

Video

Introduction and Objectives
The surgical approach to ureteropelvic junction obstruction (UPJO) in horseshoe kidneys is challenging secondary to the inherent aberrant anatomy. Historically, some have recommended division of the isthmus, while others have advocated transection of crossing vessels, both of which carry risk of nephron damage or loss. With the advent of minimally-invasive surgery, robotic-assisted laparoscopic pyeloplasty (RALP) has become routine in otherwise anatomically normal kidneys; however, there is limited data on the robotic approach to UPJO in children with horseshoe kidneys. Thus, the objective of this video is to detail the surgical approach to RALP in the horseshoe kidney.

Methods
Hidden incision endoscopic surgery (HIdES) was developed at our institution, and is applied in all RALP cases. One robotic port is placed infraumbilically, while all remaining ports are hidden below the level of a Pfannensteil incision, thus rendering them nonvisibile when wearing a bathing suit. A 5mm assist port is optional. Using a transmesenteric approach, the UPJ is localized. In this case, a mesenteric vessel overlying the UPJ was divided to maximize exposure of the UPJ and proximal ureter. High insertion was identified as the cause of UPJO in this case. No renal crossing vessels were found, and the isthmus was not a factor, thus was left intact. A hitch stitch is placed in the renal pelvis to elevate the UPJ. After transescting above the UPJ, the ureter is relocated to lie above the mesentery. The UPJ is excised and the ureter spatulated. 5-0 Vicryl is used for the anastomosis over a stent.

Results
We have performed RALP for UPJO in 4 children with horseshoe kidneys, all of whom were male, with a mean age of 4.7 years. All cases of UPJO in this cohort occurred within the left renal moiety. Mean operative time in these four cases was 120 minutes. The isthmus and renal vasculature were maintained in all cases, and there were no intra- or

post-op complications. All patients were dismissed within 24 hours. At mean follow-up of 9 months, all patients were radiologically and clinically improved.

Conclusions
In conclusion, RALP in children with horseshoe kidneys is safe and efficacious. Meticulous intraoperative examination of the anatomy is germane to ensure aberrant crossing vessels are not overlooked. Moreover, adequate drainage can be achieved without dividing the isthmus or renal vasculature, which not only maintains blood supply to all nephrons but also avoids inherent risks associated with these maneuvers. Thus, RALP is an excellent minimally-invasive approach for UPJO in children with horseshoe kidneys.

Funding: None