Boari Flap Teaching Simulation Using a Porcine Model

Objectives: Ureteral reimplant is most commonly performed due to trauma or oncologic disease affecting the distal ureter. The Boari flap is a technique by which a bladder flap is rotated cephalad and tubularized to elongate the bladder, thus allowing reimplantation of the affected ureter more proximally. It may be performed in conjunction with a psoas hitch. An existing model for a teaching simulation of Boari flap creation has not yet been described in the literature. The primary objective of this video is to illustrate a reproducible model for simulation of open abdominal Boari flap creation.

Methods: A porcine bladder with attached ureter was used for this simulation. The distal ureter is first transected to simulate a ureteral injury proximal to its entry to the bladder. The anterior edge of the transected ureter is then spatulated and tagged with a long through-and-through suture. A ‘U’ shaped flap measuring approximately 2 x 4 cm is scored with a scalpel and fully transected with scissors. The flap is oriented to open towards the ipsilateral side of the injured ureter. A submucosal tunnel is then created and an opening created through the bladder mucosa. The tagged distal end of the ureter is brought through the submucosal tunnel to exit into the bladder. Prior to stent placement, the end of the ureter is secured to the inside of the bladder with two 4-0 absorbable sutures. The stent is then placed followed by several interrupted stitches of the same suture to complete the anastomosis. Finally, the bladder wall is closed in two layers of 3-0 absorbable suture, and the previously created flap is tubularized by sewing together its lateral margins, thus elongating the bladder.

Clinical Relevance: OB/GYN and urology trainees have minimal exposure to ureteral reimplant techniques specifically involving Boari flap creation. This simulation is a realistic model of Boari flap creation that trainees can utilize to practice this procedure.