Urethroplasty for High Risk, Long Segment Urethral Strictures with Ventral Buccal Mucosa Graft and Gracilis Muscle Flap

Urethroplasty for High Risk, Long Segment Urethral Strictures with Ventral Buccal Mucosa Graft and Gracilis Muscle Flap

Trauma/Reconstruction/Diversion Urethroplasty for High Risk, Long Segment Urethral Strictures with Ventral Buccal Mucosa Graft and Gracilis Muscle Fl...

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Trauma/Reconstruction/Diversion

Urethroplasty for High Risk, Long Segment Urethral Strictures with Ventral Buccal Mucosa Graft and Gracilis Muscle Flap Drew A. Palmer, Jill C. Buckley, Leonard N. Zinman and Alex J. Vanni* From the Lahey Hospital and Medical Center, Burlington, Massachusetts, and University of California-San Diego (JCB), San Diego, California

Abbreviations and Acronyms AUS ¼ artificial urinary sphincter BMG ¼ buccal mucosa graft GMF ¼ gracilis muscle flap Accepted for publication September 17, 2014. Study received institutional review board approval. * Correspondence: Institute of Urology, Lahey Hospital and Medical Center, 41 Burlington Mall Rd., Burlington, Massachusetts 01805 (e-mail: [email protected]).

Purpose: Long segment urethral strictures with a compromised graft bed and poor vascular supply are unfit for standard repair and at high risk for recurrence. We assessed the success of urethral reconstruction in these patients with a ventral buccal mucosa graft and gracilis muscle flap. Materials and Methods: We retrospectively reviewed the records of 1,039 patients who underwent urethroplasty at Lahey Hospital and Medical Center between 1999 and 2014. We identified 20 patients who underwent urethroplasty with a ventral buccal mucosa graft and a gracilis muscle flap graft bed. Stricture recurrence was defined as the inability to pass a 16Fr cystoscope. Results: Mean stricture length was 8.2 cm (range 3.5 to 15). Strictures were located in the posterior urethra with or without involvement of the bulbar urethra in 50% of cases, and in the bulbomembranous urethra in 35%, the bulbar urethra in 10% and the proximal pendulous urethra in 5%. Stricture etiology was radiation therapy in 45% of cases, followed by an idiopathic cause in 20%, trauma in 15%, prostatectomy in 10%, and hypospadias failure and transurethral surgery in 5% each. Nine patients (45%) were previously treated with urethroplasty and 3 (15%) previously underwent UroLumeÒ stent placement. Urethral reconstruction was successful in 16 cases (80%) at a mean followup of 40 months. One of the patients in whom treatment failed had an ileal loop, 2 had a suprapubic tube and urethral dilatation had been done in 1. Mean time to recurrence was 10 months (range 2 to 17). Postoperatively 5 patients (25%) had incontinence requiring an artificial urinary sphincter. Conclusions: Urethroplasty for high risk, long segment urethral strictures can be successfully performed with a ventral buccal mucosa graft and a gracilis muscle flap, avoiding urinary diversion in most patients. Key Words: urethral stricture, recurrence, surgical flaps, transplants, radiotherapy

URETHRAL strictures can be debilitating and cause significant morbidity. Substitution urethroplasty using a BMG has become the primary surgical treatment for long segment urethral strictures that are not suitable for anastomotic urethroplasty.1

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The success rate of urethroplasty with BMG is between 81% and 96% with a recent systematic review demonstrating an overall 15.6% failure rate for substitution urethroplasty.2,3 Followup duration and the definition of success vary in

0022-5347/15/1933-0902/0 THE JOURNAL OF UROLOGY® © 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH, INC.

http://dx.doi.org/10.1016/j.juro.2014.09.093 Vol. 193, 902-905, March 2015 Printed in U.S.A.

URETHROPLASTY FOR HIGH RISK URETHRAL STRICTURES

the literature, which may under represent true failure rates, especially for complex urethral reconstruction. Long segment urethral strictures without a traditional, well vascularized graft bed present a particularly difficult challenge. These strictures are not amendable to traditional reconstructive maneuvers such as anastomotic or substitution urethroplasty with a traditional dorsal or ventral onlay approach and they carry a high risk of stricture recurrence.4 These strictures are often the result of radiation, failure of previous urethral reconstruction or hypospadias repair, severe trauma or stenting of the posterior urethra.4,5 Many of these patients ultimately require an indwelling catheter or urinary diversion. We previously proposed using a GMF as a graft bed in these patients at high risk who are candidates for traditional reconstructive techniques.4 These muscle flaps promote neovascularity and provide a well vascularized graft bed for buccal graft substitution urethroplasty. In this study we assessed the long-term success of urethral reconstruction for high risk, long segment urethral strictures with a ventral BMG and GMF in patients who were not candidates for standard repair because of a poor graft bed.

MATERIALS AND METHODS Institutional review board approval was obtained for this retrospective review. Data were collected on 1,039 patients who underwent urethroplasty at a single tertiary care hospital between 1999 and 2014. Study inclusion criteria were patients with urethral strictures who underwent urethroplasty with a ventral BMG and a GMF buttress as a graft bed. Using CPT codes for urethral reconstruction and muscle flap we identified 20 patients who fit the inclusion criteria. No patient who met these criteria was excluded from analysis. Patient demographics, stricture etiology, length and location, prior surgical procedures and surgical approach were identified from the electronic medical record. Three fellowship trained reconstructive urological surgeons (JCB, LNZ and AJV) performed the procedures. All patients underwent cystoscopy preoperatively along with retrograde or antegrade urethrography. Patients were counseled preoperatively on the possibility of a buccal graft and a gracilis flap based on stricture length and the potential for a poor graft bed based on history. The patient was placed in the dorsal lithotomy position. An inverted U-shaped incision was made over the perineum to adequately expose the bulbomembranous and distal prostatic urethra. After exposing the ventral aspect of the urethra a ventral urethrotomy was made through the stricture and ventral buccal graft onlay was performed. The gracilis muscle was harvested, rotated into the perineum and securely buttressed to the buccal

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graft with at least 4 absorbable sutures located proximal, lateral and distal to the graft to ensure proper placement of the muscle to the graft. A 16Fr urethral catheter or a suprapubic tube was left in place at the end of the procedure depending on surgeon preference. A closed suction drain was left under the muscle flap in the perineum until drainage was less than 30 ml per day. Voiding cystourethrogram was performed 3 to 4 weeks postoperatively. Patients were followed 3 to 6 months and 1 year postoperatively by subjective voiding symptoms, uroflowmetry, post-void residual urine measurement and cystoscopy. Thereafter patients were followed yearly with subjective voiding symptoms, uroflowmetry, post-void residual urine measurement and cystoscopy if there was any change in voiding symptoms or uroflowmetry. Stricture recurrence was defined as the inability to pass a 16Fr cystoscope on followup. A secondary outcome (analysis of urinary incontinence requiring an AUS) was included in our review.

RESULTS A total of 20 patients were included in this retrospective review. Mean age at surgery was 60 years (range 23 to 81) and the mean body mass index was 33 kg/m2 (range 19.3 to 55.0). All patients included in analysis had at least a 4-month postoperative followup (mean 40, range 4 to 92). Mean stricture length was 8.2 cm (range 3.5 to 15). Stricture etiology was radiation therapy in 45% of patients (9 of 20), an idiopathic cause in 20% (4), trauma in 15% (3), prostatectomy in 10% (2), hypospadias failure in 5% (1) and transurethral surgery in 5% (1). Nine patients (45%) previously underwent urethroplasty and in 3 (15%) UroLume stents had previously been placed. Six of the 9 patients (67%) previously treated with urethroplasty had undergone more than 1 urethroplasty procedure. In 18 patients (90%) prior radiation therapy or previous urethral reconstruction had been performed. One patient underwent prior prostatectomy with a perineal abscess and the remaining patient had stricture due to prior transurethral surgery. Before surgery 18 patients (90%) had undergone dilatation and/or endoscopic incision. Strictures were located in the posterior urethra with or without bulbar urethral involvement in 50% of cases (10), and in the bulbomembranous urethra in 35% (7), the bulbar urethra in 10% (2) and the proximal pendulous urethra in 5% (1). Urethral reconstruction was successful in 16 of 20 patients (80%). Of the 4 patients in whom reconstruction failed 1 underwent ileal conduit urinary diversion, 2 received a suprapubic tube and 1 was treated with urethral dilatation. In the 4 failed cases stricture etiology was external beam radiotherapy in 2, prior transurethral surgery in

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1 and prior UroLume stent placement in 1. Mean time to stricture recurrence in these patients was 10 months (range 2 to 17). Five patients (25%) had postoperative incontinence necessitating AUS placement, of whom 2 await placement. In 2 of the remaining 3 patients the AUS was removed secondary to infection. Stricture etiology in the incontinent patients was radiation in 4 and transurethral surgery in 1. Stricture location was the posterior urethra in 3 cases, and the bulbomembranous and mid bulbar urethra in 1 each. Three Clavien-Dindo classification grade II complications developed. In 2 patients infection was successfully treated with oral antibiotics (urinary tract infection and Clostridium difficile colitis, respectively). The third complication was a pulmonary embolism, which required treatment with therapeutic anticoagulation.

DISCUSSION In patients at high risk for stricture recurrence long segment urethral strictures present a unique reconstructive challenge. On multiinstitutional analyses excision with primary anastomosis was suggested as an acceptable strategy in most patients with radiation induced stricture.6,7 However, mean stricture length in these patient groups was less than 3 cm. Long segment strictures not amendable to excision and anastomosis require more complex reconstructive techniques. Substitution urethroplasty with buccal mucosa allows for urethral reconstruction of long segment strictures with excellent results and an overall reported success rate of between 79% and 96%.2,3,8,9 However, all patients in those studies had a viable graft bed for urethral reconstruction. Patients with prior radiotherapy or multiple previous urethral reconstructions are unique in that local flaps or grafts placed on these tissues are likely to be compromised by fibrotic and ischemic surfaces. The gracilis muscle is a well vascularized flap that is not compromised by previous radiation exposure or surgical fibrosis. It provides a good graft bed for substitution urethral reconstruction. The gracilis muscle can be reliably rotated into the perineum to reach the posterior and bulbar urethra without difficulty. Depending on patient body habitus, muscle anatomy and proximal vascular pedicle location the flap can also reach the pendulous urethra. To our knowledge this is the first study to date to evaluate this technique in patients who were not candidates for traditional substitution urethroplasty.

Despite the risk factors in our patient population our 80% success rate compares favorably to that in the contemporary literature even for nonirradiated, long segment strictures repaired with BMG urethral reconstruction. We believe that urethral reconstruction can be performed with a high degree of success in this difficult patient population. The GMF offers a reliable graft bed in patients in whom a traditional dorsal or ventral onlay graft would be ill advised due to prior radiotherapy or multiple previous reconstructions that created an adverse environment. The use of GMF for urethral reconstruction was demonstrated in other procedures. Gracilis muscle interposition flaps are well established to manage surgical and radiation induced rectourethral fistulas.10e12 This body of literature shows that the gracilis muscle can be harvested reliably with minimal morbidity. It is rarely compromised if a capacious subcutaneous tunnel is used and care is taken to preserve the dominant proximal vascular pedicle. Additionally, it can be mobilized to the perineum without tension and causes little morbidity at the donor site. There are several limitations to this study. The foremost limitation is that the study is retrospective in nature, which carries inherent limitations. A prospective analysis of patients with high risk, long segment strictures undergoing urethroplasty with a BMG and a GMF would be difficult due to small patient numbers. A multi-institutional approach may be beneficial to obtain significant patient numbers in prospective fashion. Additionally, it is important in the future to evaluate the impact of this type of reconstructive surgery on erectile function and patient reported incontinence. Evaluating incontinence preoperatively is difficult in patients with significant urinary obstruction. However, patients with long segment radiation strictures involving the posterior urethra must be carefully counseled on the possibility of postoperative incontinence. For example, significant incontinence developed in 5 of our patients, requiring AUS placement. Further research is needed to determine whether not transecting the urethra in this compromised patient population has the potential to decrease ischemia based urethral erosion after AUS placement. Dilating posterior and bulbomembranous strictures is an option to potentially avoid urinary incontinence in men with compromised sphincteric function. Of our patients 90% underwent at least 1 prior dilatation or urethrotomy. The decision to proceed to urethroplasty is made only after discussing all of the risks and benefits of reconstruction with the patient. We routinely offer repeat dilatations as an option for our patients.

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However, repeat dilatations in a subset of men with long segment strictures due to radiation or prior urethroplasty are futile due to the significant fibrosis of the underlying stricture. We believe that our data support using a ventral BMG and a GMF for reconstruction in these difficult patients.

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CONCLUSIONS Urethroplasty for high risk, long segment urethral strictures can be performed successfully and safely with a ventral BMG and GMF. The highly vascularized muscle flap is beneficial in patients with a poor graft bed secondary to prior radiotherapy, avoiding urinary diversion in most patients.

REFERENCES 1. Chapple C, Andrich D, Atala A et al: SIU/ICUD Consultation on Urethral Strictures: the management of anterior urethral stricture disease using substitution urethroplasty. Urology, suppl., 2014; 83: s31. 2. Bhargava S and Chapple CR: Buccal mucosal urethroplasty: is it the new gold standard? BJU Int 2004; 93: 1191. 3. Meeks JJ, Erickson BA, Granieri MA et al: Stricture recurrence after urethroplasty: a systematic review. J Urol 2009; 182: 1266. 4. Zinman L: Muscular, myocutaneous, and fasciocutaneous flaps in complex urethral reconstruction. Urol Clin North Am 2002; 29: 443. 5. Buckley JC and Zinman LN: Removal of endoprosthesis with urethral preservation and

simultaneous urethral reconstruction. J Urol 2012; 188: 856. 6. Meeks JJ, Brandes SB, Morey AF et al: Urethroplasty for radio-therapy induced bulbomembranous strictures: multi-institutional experience. J Urol 2011; 185: 1761. 7. Hofer MD, Zhao LC, Morey AF et al: Outcomes after urethroplasty for radiotherapy induced bulbomembranous urethral stricture disease. J Urol 2014; 191: 1307. 8. Erickson BA, Breyer BN and McAninch JW: Single-stage segmental urethral replacement using combined ventral onlay fasciocutaneous flap with dorsal onlay buccal grafting for long segment strictures. BJU Int 2012; 109: 1392.

9. Kulkarni SB, Joshi PM and Venkatesan K: Management of panurethral stricture disease in India. J Urol 2012; 188: 824. 10. Vanni AJ, Buckley JC and Zinman LN: Management of surgical and radiation induced rectourethral fistulas with an interposition muscle flap and selective buccal mucosal onlay graft. J Urol 2010; 184: 2400. 11. Wexner SD, Ruiz DE, Genua J et al: Gracilis muscle interposition for the treatment of rectourethral, rectovaginal, and pouch-vaginal fistulas: results in 53 patients. Ann Surg 2008; 248: 39. 12. Lane BR, Stein DE, Remzi FH et al: Management of radiotherapy induced rectourethral fistula. J Urol 2006; 175: 1382.