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Carter et al. Plast Aesthet Res 2020;7:33 I http://dx.doi.org/10.20517/2347-9264.2020.81 Page 9 of 15

It has been challenging to surgically create the anastomosis of the pars fixa and the pars pendulans of the
neourethra in a way that maintains sufficient vascular supply, promotes healing, and minimizes these
complications. It is recommended that all patients undergoing phalloplasty have the placement of a
[8]
suprapubic catheter for urinary flow diversion during the initial healing stages to prevent complications .
[11]
This usually stays in place for 2-3 weeks postoperatively . Techniques used to maximize vascularity in
this troublesome area begin with donor flap choice. The RFF flaps are generally the most well-vascularized
[3,6]
option . Additionally, careful dissection of the flap to preserve its blood supply is also imperative;
dissection of an additional 2 cm rim of nearby fatty tissue that might usually be discarded and sparing the
nearby dermis can help further preserve blood supply.

When attaching the pars fixa to the pars pendulans, it is important to create a tensionless closure. Methods to
reduce tension in this area include creating a urethral extension from the donor flap. The anastomotic suture
line can be further protected by the addition of a second well-vascularized layer over the anastomotic section
of urethra using a variety of tissues. We have studied the use of the dorsal clitoris dartos tissue, which is
dissected free and moved ventrally to cover the urethral suture line, with indeterminate results so far. Overlay
of the urethra with the gracilis flap seems to decrease the rate of stricture and fistula formation at the cost of
significant additional surgery, but has not yet been widely adopted [27,28] . Some manuscripts mention the use of
pedicled rectus flaps as an additional well-vascularized layer, but we were unable to find any scientific reports
[7]
describing its use . While coverage with the labia majora (Martius) flap has also been suggested, we hesitate
[6-8]
to disrupt the delicate labial majora flaps that are already used to create a neoscrotum in most patients .
Our group has also studied using tissue engineered technology, particularly a bioactive tissue matrix
TM
allograft composed of dehydrated human amnion/chorion membrane (dHACM) (Amniofix ; MiMedx,
Marietta, GA) to promote healing of the anastomotic urethra. dHACM is a scaffold that contains hundreds
of functioning growth factors and cytokines, including platelet derived growth factor AA (PDGF-AA),
transforming growth factor b1 (TGFb1), vascular endothelial growth factor (VEGF), fibroblast growth
factor 2 (FGF-2), interleukin (IL)-4, 6, 8, and 10, and tissue inhibitor of metalloproteinase 1 and 2 in high
[29]
concentrations and physiologic ratios . This material has been shown to promote fibroblast and endothelial
[29]
cell proliferation and support angiogenesis of the surrounding tissue . In order to decrease scarring and
improve healing in this vulnerable area, we have covered the neourethral anastomosis with a 12 cm by 2 cm
TM
piece of Amniofix , with uncertain benefit to date.

HEMOSTATIC AGENTS IN SCROTOPLASTY
Dissection of the labia majora to create the neoscrotum must maximally preserve the blood supply to these
flaps. These flaps have a large surface area, loose underlying connective tissue, and are closed into a spherical
geometric shape that tamponades bleeding poorly. Ongoing bleeding after scrotoplasty can be clinically
[9]
troublesome and result in flap necrosis, scrotal dehiscence, or urethral fistula . Rarely, some patients may
require anticoagulation after microsurgery (e.g., vessel thrombosis), which increases the risk of hematoma
TM
formation. Because of this, we routinely use a thrombin-gelatin hemostatic matrix FloSeal (Baxter
Healthcare; Deerfield, IL) to eliminate the need for scrotal drains and have limited scrotal hematoma, with
good effect.

NERVE REGENERATION
Attainment of both tactile and erogenous sensation in the neophallus is one of the principal goals of
phalloplasty. With widespread adoption of microvascular techniques, a sensate neophallus is now achievable
[8]
via microanastomosis of one or more flap nerves to the dorsal clitoral nerve of the clitoris . The donor
nerve from the flap (i.e., medial/lateral antebrachial cutaneous nerve from a RFF flap, or femoral cutaneous
nerve from an ALT flap) is microanastamosed to one of the two dominant dorsal clitoral nerve branches.