Page 363 - Read Online
P. 363

Page 8 of 15                                          Carter et al. Plast Aesthet Res 2020;7:33  I  http://dx.doi.org/10.20517/2347-9264.2020.81

               are the same as those for native male urethral repair [11,24] . Unfortunately, these repairs have a high predicted
                                                             [24]
               failure rate, reported as high as 50% in this population . In some cases, especially those requiring multiple
                                                                                                [24]
               surgical interventions, a temporary or permanent perineal urethrostomy may be necessary . Patients
               generally are at risk for stricture formation for at least 1 year, although most strictures present within the first
                                      [11]
               6 months after phalloplasty .

               Fistulas have overall lower morbidity than strictures. 17%-35% of fistulas may heal spontaneously within
                                                             [24]
               3 months without the need for surgical intervention . If spontaneous recovery does not occur, surgical
                                                [24]
               repair has a high expected success rate . Small (< 5 mm) fistulas are good candidates for a primary repair,
                                                                           [11]
               whereas larger fistulas (> 5 mm) may require a graft to cover the defect . Patients who do not elect to have
               vaginectomy have an especially high (up to 60%) risk for urethrocutaneous fistulas [11,25] .

               Asymptomatic pseudodiverticula are very common at the point between the native urethra and the pars fixa.
               They can be more prominent in those with high pressure voiding from a more distal anastomotic stricture,
               but almost always decompress when the distal obstruction is treated. Uncommonly, these pseudodiverticula
               may suffer urinary tract infections from trapped urine, or cause significant post-void dribbling that may
                                       [6]
               require surgical management .
               Meatal stenosis is a short narrowing of the most distal portion of the penile urethra and is thought to be
                                                                                                   [8]
               caused by local ischemia of a watershed region, leading to contracture of the skin at the meatus . This
                                                                                                 [24]
               complication is generally straightforward to treat through meatoplasty with good outcomes . Meatal
                                                                                          [24]
               stenosis generally does not have significant long-term urinary consequences when treated .
               Multiple urethral complications may occur concurrently, and many patients with urethral complications may
                                                             [7]
               present with numerous simultaneous urologic findings . For example, in RFF phalloplasty, fistulas are often
               located immediately proximal to a concurrent stricture or urethral trichobezoar/hairball [7,14] .

               There are several methods of creating the neourethra, but we currently use the TWT almost exclusively.
               Prelamination of the RFF or ALT with buccal mucosal graft or even vaginal mucosa harvested from
               vaginectomy has been proposed, but requires an additional staged surgery without significant improvement
               in outcomes [8,10] . Additionally, these grafts heal by scarring into the tissue over which they are placed, and
               do not seem to be an improvement over the healthy, unscarred, well-vascularized arm/leg tissue they are
               meant to replace. Creating an ALT neourethra out of a second free flap harvested from the forearm has
               also been proposed, but we and others are concerned that the addition of a second free flap (especially to
               the ALT surgery which only requires a pedicled flap) invites a potentially dangerous second microvascular
               anastomosis and may not provide any advantage to the patient [6,10] .

               Improvements in pars fixa creation
               A critical improvement in phalloplasty came from using bulbospongiosus muscle flaps as a second layer of
                                                                                       [26]
               the proximal pars fixa. It greatly decreased the rate of fistulas and strictures in this area . This is an essential
               step in our urethral lengthening technique when vaginectomy is simultaneously performed. Additionally,
                                                                                [26]
               we cover the more distal pars fixa with a second layer of labial minora tissue . These additional layers are
               thought to reinforce the vascular supply of the pars fixa, and have further reduced the rate of fistulas and
               strictures in this area dramatically.


               Improvements in distal urethral anastomosis
               The anastomosis of the pars fixa with the pars pendulans is the most common site for urethral strictures and
                                    [7,8]
               fistulas after phalloplasty . The higher prevalence of anastomotic strictures and fistulas here is most often
               attributed to local ischemia in this “double watershed” zone where the edge of the neourethra portion of the
                                                                                                       [6,8]
               flap has the poorest blood flow, and the edge of the pars fixa urethra flaps have their poorest blood supply .
   358   359   360   361   362   363   364   365   366   367   368