POINT-COUNTERPOINT Posterior Urethral Stenosis After Prostate Cancer Radiotherapy, What Is the Best Perineal Approach: Transecting Anastomotic vs Dorsal Buccal Inlay
By: Bryan Voelzke, MD, MS, Spokane Urology, Washington | Posted on: 25 Oct 2023
Transecting anastomotic posterior urethral stenosis following prostate cancer radiotherapy is an unfortunate outcome in the field of urologic reconstruction. The delayed impact of radiation-induced tissue ischemia and vascular insufficiency negatively impact surgical reconstruction outcomes and require careful consideration regarding optimal surgical candidates. Limited bladder capacity (<200 mL), concomitant radiation cystitis, pubic osteomyelitis, and/or dystrophic prostatic urethra calcification are considered absolute contraindications for surgical reconstruction in my practice. Concomitant stress urinary incontinence requires special counseling and can impact objective and subjective surgical outcomes. Most patients are at an advanced age with potentially complex medical issues that can also impact candidacy for surgery. Consideration of all these variables is necessary before proceeding with surgical reconstruction.
Transecting anastomotic urethroplasty has historically been considered the definitive method of surgical reconstruction. A concern of transecting anastomotic urethroplasty, though, is the impact of urethral transection on immediate/delayed tissue vascularity. Subsequent surgical approaches for radiated urethral stricture patients have been published to address this concern. These include antegrade robotic transvesical buccal graft inlay, antegrade YV bladder neck reconstruction, perineal dorsal buccal graft urethroplasty, and perineal ventral buccal graft urethroplasty with gracilis interposition muscle flap.1-3 Antegrade approaches can reduce iatrogenic stress incontinence among select postradiation patients with an intact external urinary sphincter and bladder neck stenosis (ie, antegrade robotic approaches for the post-transurethral resection of the prostate radiated patient with bladder neck stenosis).
I have continued to employ transecting anastomotic urethroplasty as the primary surgical approach in my practice; however, the alternative above-mentioned approaches have also immensely benefited my patients. My use of the transecting approach is based upon reliable surgical success among carefully screened patients. We have previously published a multi-institutional study from the Trauma and Urologic Reconstruction Network of Surgeons.4 A total of 137 patients underwent transecting anastomotic urethroplasty. Patients with single and combined radiation for prostate cancer were included. Adjunctive techniques such as corporal splitting (71.5%), partial perineal prostatectomy (37.2%), gracilis interposition muscle flap (23.4%), partial pubectomy (12.4%), combined antegrade approach (5.8%), salvage prostatectomy (2.2%), and/or complete pubectomy (0.7%) were at the discretion of the surgeon based upon operative findings. The overwhelming majority of patients had bulbomembranous urethral strictures. Prostate involvement (most commonly an extension of the membranous urethral stricture into the prostate apex) was present in half of patients and a small subset had bladder neck involvement (9.5%) or a rectourethral fistula (2.2%). Average stricture length was 2.3 cm, and average patient age was 69 (50-86) years old. Cystoscopy was utilized to assess surgical outcome. Overall success at a mean followup of 32 months was 86.9%.
Subsequent artificial urinary sphincter was performed in 22% of the cohort, with the majority via a transcorporal cuff to reduce the risk of urethral erosion. Among these patients with mixed stricture location, 20% developed subsequent cuff erosion. In a separate published series of men with bulbomembranous urethral strictures alone, we compared stress incontinence among men with radiated strictures or pelvic fracture urethral injuries.5 We used an outcome measure to assess the occurrence of any degree of stress incontinence. De novo stress incontinence was reported in 33% of the postradiated men (vs 12% pelvic fracture cohort); however, only 16% of the radiated cohort underwent subsequent urinary sphincter.
The surgical approach for transecting anastomotic urethroplasty follows the same approach to a patient with a pelvic fracture associated urethral stricture. A suprapubic tube is placed 1 month before surgery to allow for urethral rest. Bladder capacity is assessed at that time, and patients are strongly advised against surgery based upon above-mentioned contraindications, if noted. A perineal incision is performed with dissection performed to the level of the stricture based upon preoperative fluoroscopic imaging. The urethra is mobilized circumferentially. Before urethral transection, the tissue plane above the dorsal proximal bulbar urethra is carefully dissected in a proximal manner toward the prostate apex to increase surgical exposure. Careful dissection along the ventral plane of the proximal bulbomembranous urethra is performed in anticipation of urethral transection. Rectal exam can be performed to confirm proximity to the rectum during this dissection. The urethra is then transected. Additional dissection via scalpel and/or metzenbaum scissors is performed predominately along the dorsal plane of the urethra to gain exposure cephalad to the stricture. Van Buren sounds can be passed via the suprapubic tube tract to aid location of the proximal urethral lumen, if needed. Urethral calibration to 30F is performed.
Urethral mobilization of the distal transected bulbar urethra is always necessary to allow a tension-free urethral anastomosis. Corporal splitting can be performed to gain additional urethral mobilization for the planned anastomosis. I have rarely performed an infrapubic partial pubectomy. If performed, gracilis interposition muscle flap is utilized to place along the exposed bone to reduce the risk of pubic osteomyelitis. I will also use a gracilis interposition muscle flap for large tissue defects and/or for patients with combined radiation. Cystoscopy is performed in all patients prior to anastomosis. Twelve-suture interrupted anastomosis is performed akin to a clock face with 4/0 PDS utilized at 12:00, 3:00, 6:00, and 9:00. The remaining sutures are 5/0 PDS. The suprapubic catheter is left in place in addition to the urethral catheter (1 is capped). Voiding cystourethrography is performed in 4 weeks. Cystoscopy is performed in additional to use of a patient reported outcome measure at 3 months following surgery. For patients with stress incontinence, artificial urinary sphincter is performed at 6 months after confirming urethral repair stability on cystoscopy at 3 and 6 months. I have erred on the side of a looser cuff and utilize a transcorporal cuff among these patients to augment success. I am encouraged by innovations to improve outcomes and quality of life among men with radiated urethral strictures and welcome the increased attention on this subject to inform the urology audience pertaining surgical approaches.
- Cavallo JA, Vanni AJ, Dy GW, et al. Clinical outcomes of a combined robotic, transabdominal, and open transperineal approach for anastomotic posterior urethroplasty. J Endourol. 2021;35(9):1372-1377.
- Palmer DA, Buckley JC, Zinman LN, Vanni AJ. Urethroplasty for high risk, long segment urethral strictures with ventral buccal mucosa graft and gracilis muscle flap. J Urol. 2015;193(3):902-905.
- Policastro CG, Simhan J, Martins FE, et al. A multi-institutional critical assessment of dorsal onlay urethroplasty for post-radiation urethral stenosis. World J Urol. 2021;39(7):2669-2675.
- Voelzke BB, Leddy LS, Myers JB, et al. Multi-institutional outcomes and associations after excision and primary anastomosis for radiotherapy-associated bulbomembranous urethral stenoses following prostate cancer treatment. Urology. 2021;152:117-122.
- Chung PH, Esposito P, Wessells H, Voelzke BB. Incidence of stress urinary incontinence after posterior urethroplasty for radiation-induced urethral strictures. Urology. 2018;114:188-192.