How is a Boari flap performed for iatrogenic ureteral injury repair?

Updated: Nov 12, 2020
  • Author: Sandip P Vasavada, MD; Chief Editor: Bradley Fields Schwartz, DO, FACS  more...
  • Print

After preparing and draping the patient, a midline or Pfannenstiel incision is made. Once the transversalis fascia is incised, the ureter may be approached either transperitoneally or retroperitoneally. In the transperitoneal approach, the peritoneal cavity is entered, the sigmoid or cecum is reflected medially, the posterior peritoneum is incised, and the ureter is identified. In the retroperitoneal approach, care is taken not to enter the peritoneal cavity, the peritoneum is mobilized medially, and the ureter is identified and exposed. A stay stitch is placed in healthy ureter tissue just proximal to the injury. The remaining end of the ureter is tied off.

The peritoneum is then dissected from the wall of the bladder. This dissection may be facilitated with hydrodissection, in which saline is injected subperitoneally, separating the peritoneal layer from the muscle layers of the bladder.

The necessary length of the bladder flap (ie, the distance between the posterior wall of the bladder and the end of the healthy proximal ureter) is measured with umbilical tape, the bladder is one half full of saline, and the length and shape of the bladder flap are planned. To measure accurately on the dome of the bladder, several stay stitches are placed at the base of the proposed bladder flap and at the apex. The bladder flap should be planned with a large base, because the base will contain the blood supply for the flap. The length of the bladder flap (ie, the distance between the base and apex) should equal the distance between the posterior wall of the bladder and the end of the healthy proximal ureter. The width of the apex should be at least 3 times the diameter of the ureter to prevent constriction after the flap is tubularized. Avoid scarred areas of the bladder.

After proper planning, an outline of the flap is made in the bladder wall with coagulating current, and the bladder flap is remeasured. If the measurements are satisfactory, the bladder flap is cut via cutting current, and the concomitant bleeding vessels are coagulated. See the image below.

An illustration of the shape and configuration of An illustration of the shape and configuration of a Boari flap.

After the bladder flap is turned superiorly, Lahey scissors are used to prepare a ureteral tunnel. The tunnel should be at least 3 cm long and is created by placing the Lahey scissors submucosally at the apex of the flap, tunneling the appropriate distance and coming out through the mucosa. Submucosal injection of saline may aid in this dissection. An 8F feeding tube is pulled through the tunnel by the scissors and the stay suture on the proximal ureter is tied to the feeding tube after the ureteral end is spatulated. The feeding tube is pulled toward the bladder, followed by the ureter. The stay suture is cut after the ureter has traveled completely through the tunnel.

The bladder flap is sutured to the psoas tendon of the psoas minor with a few 2-0 absorbable sutures. These sutures fix the flap in place to prevent tension on the ureteral anastomosis.

The ureter is anastomosed to the bladder mucosa with several 4-0 absorbable sutures. A few of the sutures should include the muscle layer of the bladder to fix the ureter into place. An 8F feeding tube is passed up the ureter into the renal pelvis and out through the bladder and body wall.

Before closing the bladder, a large suprapubic tube is placed, ie, either a 22-24F Malecot or Foley. Then, the bladder is closed by approximating the bladder mucosa with a 3-0 absorbable running suture followed by a second row of running sutures, which approximates the muscularis and adventitial layers. A few absorbable sutures (5-0) can be placed to approximate the distal end of the flap to the adventitia of the ureter. If a transperitoneal approach is used, close the peritoneum and then place a Penrose or a JP drain retroperitoneally adjacent to the bladder closure. The anterior abdominal fascia and skin are closed.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!