Dorsal vs. Ventral Buccal Graft Dorsal vs. Ventral Buccal Graft
Dorsal vs. Ventral Buccal Graft Dorsal vs. Ventral Buccal Graft
This is a randomized non-blinded comparison of dorsal vs. ventral approach for buccal mucosa
 graft urethroplasty in the bulbar urethra. Buccal mucosa graft is a common method of
 repairing the strictured urethra. Current evidence suggests the two approaches for placement
 of the graft are equally successful at correcting the stricture and the two approaches have
 similar risks of complications. The investigators propose to randomly assign appropriately
 selected patients to either a dorsally- or ventrally-placed graft. No additional procedures
 beyond the normal care protocol will be required of the patients. Success will be assessed
 via objective and subjective methods; complications will be tallied in a standardized
 fashion. Outcomes will be measured at two years.
Urethral strictures affect 1% of men and are rare in women. Most urethral strictures in the
 United States develop in the bulbar section of the urethra which is the section of the
 urethra proximal to the penis but distal to the prostate. A common method of surgical
 correction is to longitudinally open the strictured urethra and augment its width by the
 addition of a graft of buccal mucosa taken from the oral cavity. The urethrotomy for
 placement of the graft can be made along the superficial (ventral) or deep (dorsal) side of
 the urethra. The graft bed dorsally is the tunica albuginea of the corporal bodies (the
 capsule around the erectile bodies of the penis) whereas ventrally it is the corpus
 spongiosum of the urethra (the vascular layer that surrounds the urethra).

 Ventral buccal graft onlay first described by Morey and McAninch in 1996, involves a midline
 perineal incision and retraction of the bulbo-spongiosum muscle downward to expose the
 ventral urethral surface. The corpus spongiosum is incised longitudinally to expose the
 urethral lumen and the incision is extended proximal and distal to the established stricture.
 The buccal mucosa graft is harvested and trimmed to the length and width of the urethrotomy
 and the graft is sutured at the proximal and distal apices and a running suture at the
 lateral margins to establish a tight anastomosis. Ventral placement allows for limited
 urethral mobilization and easy access but there is concern about higher likelihood of
 diverticulum formation and development of associated complications such as post-void
 dribbling and ejaculatory dysfunction. In addition, many surgeons have concern about graft
 contraction as spread-fixating the graft is not possible.

 Dorsal buccal graft onlay, first described by Barbagli in 1996, also involves a midline
 perineal incision. The bulbo-cavernosum and corpora cavernosum are dissected from the bulbar
 urethra allowing for complete mobilization of the urethra. The urethra is rotated 180 degrees
 to allow for dorsal access and an incision is made on the dorsal urethra proximal and distal
 to the stricture location. The buccal graft is harvested and trimmed to the appropriate size
 of the urethrotomy and spread on the overlying tunica albuginea of the corporal bodies. The
 right mucosal margin of the urethra is sutured to the right margin of the buccal graft and
 the corporal bodies. The urethra is rotated back to allow for suturing of the left mucosal
 margin to the left margin of the buccal graft and corporal bodies, essentially covering the
 entire urethral plate. Dorsal placement potentially allows for a more stable vascular bed for
 graft sustainability and less spongiosal bleeding, but requires a greater urethral
 mobilization and longer operative times. The technical challenge of graft placement in a
 dorsal location is much greater than placement ventrally. Potential problems with dorsal
 placement include damage to the male external urinary sphincter, which is dorsally located,
 and anastomotic leakage and perineal abscess in the immediate post-operative period.

 There are multiple studies that attempt to compare the outcomes of ventral versus dorsal
 graft placement for bulbar urethroplasty, but these studies rely on case series and
 retrospective data. Andrich and Mundy reported better outcomes with dorsal buccal placement,
 but statistical significance was not formally established. Both Barbagli and Figler were
 unable to demonstrate superiority of either ventral or dorsal buccal graft placement.
 Currently there is no high level of definitive randomized evidence to suggest superiority of
 either ventral or dorsal buccal placement in terms of patient outcomes and complications. In
 fact, the best level of evidence is VI (small case series) and dorsal vs. ventral placement
 is largely dependent on individual clinical judgment and comfort level with each procedure.

 One factor contributing to the inability to detect a difference between dorsal vs. ventral
 graft placement has been the liberal definition of success that leads to uniformly high
 success rates across studies (85-95%) and, hence, studies that are underpowered to detect a
 difference in success rates. In these studies, the definition of success has typically been
 "need for repeat surgery". Such a definition suffers from significant detection bias in that
 (1) subclinical stricture recurrences may go undetected if they are not screened for; and (2)
 surgeon or patient reluctance to undergo a repeat surgery may lead to false negatives. When
 patients are rigorously followed with endoscopic inspection of the area of surgery with
 cystoscopy, narrowing is often identified at a much higher rate than "need for repeat
 surgery". For instance, in a preliminary review of our retrospective data using surveillance
 cystoscopy, the investigators detected narrowing in 46% of ventral buccal patients and
 approximately 18% of dorsal buccal patients. This more strict definition of success and the
 lower success rates that follow may allow for detection of a clinically meaningful difference
 in the success rate with the two procedures in a reasonably-sized clinical trial.

 The investigators plan a randomized comparison of dorsally-placed vs. ventrally-placed buccal
 mucosa graft in men undergoing buccal graft urethroplasty for bulbar urethra stricture. A
 collaborative multi-institutional study deriving data from the Trauma and Urologic
 Reconstruction Network of Surgeons, a network of twelve reconstructive urology centers in the
 United States, would allow the investigators to achieve the required sample size within 2-3
 years. The results of this study will ultimately advance research efforts in urethral
 stricture management and provide substantial evidence for utilization of ventral versus
 dorsal buccal placement for reconstructive urologists.
Inclusion Criteria:

 -  Strictures must predominantly include the proximal and/or mid bulbar urethra and be
 otherwise amenable to buccal graft onlay urethroplasty

 -  Strictures may extend from the mid-bulbar urethra up to the distal bulbar urethra
 within the scrotum, but not through the scrotum to the pendulous junction

 -  Subjects able to consent for themselves

 Exclusion Criteria:

 -  prior open urethral surgery, such as prior urethroplasty, artificial urinary sphincter
 placement, male urethral sling placement, and rectourethral fistula

 -  radiation therapy to the pelvis

 -  previous hypospadias repair

 -  lichen sclerosis unable to consent for themselves