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Phalloplasty and metaoidioplasty - overview and postoperative considerations

Primary author: Curtis Crane, MD

Introduction

Phalloplasty in transgender men involves the creation of a penis using any one of a number of procedures; either a free flap or pedicled flap of skin, usually taken from the arm (radial forearm free-flap, RFF) or anterior lateral thigh (anterior lateral thigh pedicled flap phalloplasty, ALT). In a free flap procedure, tissue is completely removed from the donor site along with its blood supply. The blood supply is then anastomosed to a recipient blood supply at the site of transfer. In a pedicled flap procedure, the tissue is never severed from its blood supply. Using either procedure, the donor skin is rolled into a tube like structure and grafted to the inguinal area. In order to minimize the risk of fistula, most commonly this procedure is performed after a hysterectomy and vaginectomy (or vaginal mucosal ablation) is performed. Scrotoplasty may also be performed using skin flaps. Scrotoplasty may be performed with or without testicular implants. A urethral hookup may be performed using cheek or vaginal mucosa, and an erectile implant may be placed. Often the entire phalloplasty procedure involves multiple staged surgeries, with earlier stages allowing skin grafts to develop local blood supply prior to cosmetic procedures to complete the phalloplasty. Depending on the surgical approach, the penis may or may not have intact erotic sensation.

Risks associated with phalloplasty

There are general risks associated with any surgery, including infection, bleeding, damage to surrounding tissues, and pain. Specific to phalloplasty in transgender men, there is risk of flap loss, urethral complications, wound breakdown, pelvic bleeding or pain, bladder or rectal injury, lack of sensation, prolonged need for drainage, or need for further procedures. Donor site risks include unsightly scarring, wound breakdown, granulation tissue formation, decreased mobility, hematoma, pain and decreased sensation. If patients are discharged from their surgeon's care and are not local, they should see their primary care provider every three months during the first year.

Some of the most common complications are listed below. Different techniques and approaches can have varying levels of complexity. Different surgeons may also have different complications rates; understanding what procedures different surgeons perform, their experience, frequency with which they perform these procedures, and complication rates is helpful.

Immediate/early (within one month) complications after free or pedicled flap phalloplasty

Wound infections typically occur within the first few weeks after surgery and can present as cellulitis, fungal infection or both. Antibiotics and antifungal cream are usually sufficient for treatment. In some cases intravenous antibiotics may be required.

Wound breakdown is common and typically occurs at points where multiple suture lines meet (i.e. perineal-scrotal junction and base of phallus). Most wound breakdown issues can be managed with local wound care (wet to dry dressing changes) as the wounds heal by secondary intention. Some wound breakdowns may require debridement(s), and fewer may require skin grafting or further surgical procedure(s) to close the wound.

Urinary catheter difficulties present as a clogged catheter or bladder spasms. This is managed by making sure there are no kinks or twists in the tubing, flushing the catheter, and antispasmodic medications (anticholinergics). Urinary tract infections (UTIs) in the setting of a urinary catheter can develop and present with a constellation of symptoms including cloudy urine, odorous urine, increased bladder spasms or leakage around catheter. These symptoms may or may not present with fever or other systemic symptoms. If a patient does not have a constellation of these symptoms, it is unlikely to be a true UTI even if the urinalysis (UA) and urine culture (UCx) demonstrate laboratory findings consistent with infection.

Flap loss is rare and typically occurs due to technical error (misplaced microsurgical suture or vascular pedicle kinking/compression). Flap loss typically presents within the first 72 hours, and if recognized early (within hours) can be salvaged by emergent return to the operating room. On return to the OR, drainage of a hematoma compressing the vascular pedicle, revision of the arterial or venous anastomosis, or in some cases mechanical thrombectomy with balloon catheters or instilling tissue plasminogen activator (tPA) into the flap can save a flap from loss. Even with these measures, partial or complete flap loss is possible. Hypercoagulable states can predispose a patient to clotting after surgery and flap loss. Undiagnosed clotting disorder such as Factor V Leiden, antiphospholipid syndrome, prothrombin gene mutation G20210A, antithrombin III deficiency, Protein C and S deficiency, and hyperhomocysteinemia should be considered in the case of flap thrombosis.

Pelvic or groin hematomas can occur, and may be managed by drains, or may require surgical drainage. While medical deep vein thrombosis prophylaxis with unfractionated heparin or lovenox may place the patient at higher risk of hematoma formation, this risk must be weighed against the risk of deep vein thrombosis and pulmonary emboli. Risk assessment models exist to help determine individualized perioperative anticoagulation modalities.[1] While these risk assessments will generally be performed by surgeons, primary care providers with knowledge of an individual patient's increased risk for thromboembolism or perioperative bleeding should notify surgeons pre-operatively.

Rectal injury is a rare but serious complication. The vaginectomy portion of the procedure involves developing a plane between the posterior wall of the vagina and the anterior wall of the rectum. Laceration with scissors or cautery can cause this injury. Inadvertent injury to the rectal wall can present acutely (immediately known and repaired) or subacutely (days to weeks later). Recognition of a rectal injury in the subacute period can be based on constitutional symptoms of fever, chills, malaise, or more overt symptoms of sepsis. The portion of the rectum in the surgical field is extraperitoneal, so abdominal pain or peritoneal signs would be unusual. Drainage of stool from the perineal incisions, scrotum or base of the phallus indicates formation of a fistula between the rectal wall and the skin. Such wounds require hospitalization and general surgical involvement in the care plan. A short-term colostomy may be required to divert the fecal stream and allow the fistula to close. Washout of a pelvic abscess and closure of the rectal fistula, with secondary wound healing may be required.

Long-term complications after free or pedicled flap phalloplasty

Urethral strictures typically present 6-12 months after surgery with symptoms of a weak stream, straining with urination, and sometimes concomitant fistulas secondary to distal obstruction from the stricture. This will require surgical intervention with either dilation or urethroplasty.

Wound contraction and scarring are complications that occur any time the skin is cut, but the degree to which they occur is highly variable between patients. Some patients form scar more robustly than others. All scars contract with time as myofibroblasts within the wound become active in the first 2-9 days.[2] Wound contracture is a natural mechanism to decrease the defect size, decreasing the effective surface area that must be healed. However, wound contracture can lead to distortion of surrounding tissues and contour defects. Wounds that close by secondary intent show more contracture than primary closure.

Scars can be thin lines, or can widen or become "proud" (hypertrophic), or even pass beyond the borders of the scar (keloid). Hypertrophic scars can successfully be revised by excision and reclosure with skin tension reducing measures to decrease recurrence. Keloids occur infrequently, often in people predisposed to keloid formation. The recurrence of keloids after simple excision and closure is very high (at least 70%). Steroid injections, silicone and compressive dressings, and radiation therapy have been offered as treatment modalities, with limited improvements in recurrence rates.

Granulation tissue is common at the donor site around and within the skin graft. Its appearance represents an over exuberant proliferation of fibroblasts and small blood vessels. Most granulation tissue can be treated with topical application of silver nitrate applied periodically over several office visits, as needed. Silver nitrate can lead to dark discoloration of the treated tissues, which can persist for weeks to months. However, granulation tissue rarely requires more involved treatment.

Corona flattening can occur on occasion and may require revision surgery done at the same time of the 2nd stage surgery (typically penile and testicular implantation)

Erectile implants

Roughly nine months after the penis is created, the patient can have a penile implant placed to allow rigidity for penetration. Currently there are no FDA approved implants specifically created for transgender patients. As such, implants created for non-transgender males with erectile dysfunction are rigidly fixed to the pubic bone. Complications can include infection and erosion.

Infection is the most common complication of the penile implant. Pre and post op antibiotics reduce the risk, as well as intraoperative sterile technique. If an implant becomes infected, it typically has to be removed. A new implant may be replaced six months later.

Erosion is when the implant protrudes through the skin of the phallus or the urethra. The presence of sensation in the phallus, and avoiding an excessively large implant reduce the risk of erosion. As with infection, erosion of an implant necessitates surgical removal.

Dysuria

Should a recently postop phalloplasty patient have dysuria, the best approach is to obtain a urine culture. Urinalysis is of little value as white and red cells can be detectable in normal post op patients for months after reconstruction. If a urine culture is positive, the infection should be treated with culture specific antibiotics. If it is negative, the most likely culprit is a urethral stricture, which should be evaluated by the surgeon who performed the phalloplasty, or if unavailable, a local urologist.

Metoidioplasty

Metoidioplasty (metaoidioplasty) is a Greek word that means "towards male genitalia." Testosterone causes growth of the clitoris; metoidioplasty uses only local tissue (no grafting) to create a smaller, 1 to 3 inch phallus with girth approximately the size of someone's thumb. Patients may opt to have a urethra placed in the phallus, but not all patients choose to do this. A scrotum can also be created from the labia majora and a vaginectomy may be performed. Because metoidioplasty is a shorter procedure, occasionally hysterectomy is performed at the same time as metoidioplasty. Some surgeons may use tissue expanders to create the scrotum, while others do not find this necessary. Testicular implants are typically placed at a second stage approximately 4 months later. While the phallus is not large enough to accept a penile implant, erections are possible since the procedure involves the use of natal clitorial and other genital tissues.

Complications associated with metoidioplasty are very similar to free flap phalloplsaty, except for flap loss since no flap is used. Wound breakdown, infection, urethral stricture and fistula are all seen in similar anatomic sites to that of free flap phalloplasty, although the incidence is lower in metoidioplasty. Risks such as coronal flattening do not occur in metoidioplasty, as the corona does not require sculpting in metoidioplasty. Management of complications similar to as is detailed in the phalloplasty section.

  1. Pannucci CJ, Bailey SH, Dreszer G, Fisher Wachtman C, Zumsteg JW, Jaber RM, et al. Validation of the Caprini risk assessment model in plastic and reconstructive surgery patients. J Am Coll Surg. 2011 Jan;212(1):105-12.
  2. Hinz B. Formation and function of the myofibroblast during tissue repair. J Invest Dermatol. 2007 Mar;127(3):526-37.