Bladder Flap Repair (Boari)





Excision or transection of the ureter for stricture disease, trauma, or malignant disease requires reconstruction that is variable depending on the defect length and location. Distal ureteral reconstruction is usually best managed by ureteral reimplantation with or without a psoas hitch. Mid- and distal reconstruction often requires use of a Boari-Ockerblad flap to bridge the larger gap (≤10–15 cm in length) between the ureter and the bladder to create a tension-free anastomosis. If there is bilateral ureteral involvement, bilateral Boari flaps may need to be used. Preoperative evaluation to assess bladder capacity and function should be addressed. A small bladder capacity can be associated with inadequate Boari flap creation.


The patient is positioned supine. A Foley catheter to facilitate intraoperative bladder filling is placed in a sterile fashion after prepping and draping.


A subumbilical midline or Pfannenstiel incision is appropriate. This decision for the incision may be affected by a previous scar from the original iatrogenic cause.


An extraperitoneal approach is ideal, yet in cases of significant ureteral fibrosis, this may not be possible. The peritoneum is mobilized medially, along with either the vas deferens or round ligament, to expose the proximal ureter. To expose the normal ureter above the defect, it is best to identify the ureter at or above the level of the bifurcation of the common iliac artery. Reflect the colon medially and open the posterior peritoneum along the lateral gutter. Using a vessel loop, encircle the ureter and dissect the ureter distally until the ureteral defect or diseased portion is reached. In cases with is significant ureteral scarring, an intraperitoneal approach through a midline incision is ideal because a retroperitoneal approach may risk injury to the iliac vein during ureteral mobilization.


The peritoneum is freed off the posterolateral bladder surface to prepare a bladder flap. This may be assisted by infiltration of saline to delineate the layers. Isolation and division of the urachal remnant may also assist with bladder mobilization. The peritoneum may later be used to cover the Boari flap anastomosis.


Ureteral preparation involves excision of the diseased portion and placement of a fine stay suture on the distal aspect of the healthy ureter. The bladder should be fully mobilized on the opposite side of the planned Boari flap. This requires division of the superior vesicle pedicle and only rarely the inferior vesicle pedicle. After the bladder is distended with normal saline, measure the distance from the posterior bladder wall to the proximal cut end of the ureter. The outline of the flap is marked with a marking pen. The flap should be at least 4 cm wide at the base and 3 cm at the tip (or three times the diameter of the ureter) to avoid constriction of the ureter after tubulization. The flap length should equal the length of the ureteral defect plus an additional 3 to 4 cm if a nonrefluxing anastomosis is planned. Overall, the ratio of flap length to base width should not be greater than 3 to 1 to avoid flap ischemia. If greater length is required and bladder capacity permits, an oblique or S -shaped incision can be made.


Stay sutures are placed just outside the four corners of the planned flap. The flap may be reoutlined with a weak coagulation current. The flap dimension should be rechecked after emptying the bladder. On cutting current, incise the bladder wall across the distal (narrow) side of the flap ( Fig. 34.1 ). A 5-Fr feeding tube or Pollack ureteral catheter should be placed in the contralateral ureter to avoid injury during flap closure. Using an index finger, elevate the ipsilateral posterior bladder wall toward the psoas tendon and hitch in place with 2-0 Vicryl sutures (in a vertical orientation), avoiding the ilioinguinal and genitofemoral nerves. This will relieve tension off the ureteral anastomosis and make the anastomosis technically easier.




FIGURE 34.1


Incise the bladder wall across the distal (narrow) side of the flap.


The bladder flap should overlap the ureter by at least 3 cm to allow for a proper submucosal tunnel. Ureteral mobilization may be necessary to achieve a tunnel, but care should be taken to protect the ureteral adventitia to avoid ischemia. If the ureter is still too short or the distal ureteral defect is too long, then omission of the tunnel and creation of a refluxing anastomosis is preferred. This involves direct anastomosis of the spatulated distal ureteral stump to the edge of the bladder flap with multiple 4-0 Vicryl sutures. If the ureter is still unable to bridge the gap in a tension-free manner, then the kidney may be mobilized within Gerota fascia and moved down to gain an additional 4 to 5 cm of ureteral length.


Create a 3-cm submucosal tunnel with Metzenbaum or Lahey scissors after hydrodistention with saline. After bringing the tips of the scissors through the mucosa, the ureter is brought through the tunnel with use of an 8-Fr feeding tube. The broad end of the feeding tube is installed on the closed scissors tips and drawn up through the tunnel ( Fig. 34.2 ). Place a ureteral stay suture in the tube and draw the ureter through the tunnel ( Fig. 34.3 ). Spatulate the ureter obliquely. The superior end of the Boari flap is fixed to the psoas minor muscle and tendon in a vertical orientation with 3-0 Vicryl, with care taken to avoid the genitofemoral and ilioinguinal nerves. This is an additional step to avoid tension on the anastomosis. A 4-0 Vicryl is used to tack the apex of the ureter to the bladder wall (mucosa and muscularis), and then the anastomosis is completed with multiple interrupted sutures ( Fig. 34.4 ).


Jan 2, 2020 | Posted by in UROLOGY | Comments Off on Bladder Flap Repair (Boari)
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