Metoidioplasty vs Phalloplasty: Key Surgical Differences

Gender-affirming surgeries offer different options for individuals seeking masculinizing procedures, with metoidioplasty and phalloplasty being two primary choices. Each approach has distinct techniques, outcomes, and considerations that influence a person’s decision based on anatomy, functionality, and recovery time.

Understanding these differences is essential for making an informed choice.

Metoidioplasty Surgical Framework

Metoidioplasty utilizes hormonally enlarged clitoral tissue to create a neophallus, offering fewer surgical stages and a shorter recovery period than phalloplasty. It is well-suited for individuals prioritizing erogenous sensation while achieving a natural genital appearance. Testosterone therapy plays a foundational role, as prolonged androgen exposure causes clitoral hypertrophy, typically increasing length to 3–6 cm.

The procedure involves releasing the clitoral suspensory ligament to enhance projection, maximizing length while preserving vascular integrity. Surrounding tissues are repositioned to create a more prominent structure. Scrotoplasty may be performed concurrently using labial tissue to construct a scrotum, which can later accommodate testicular implants. The extent of tissue mobilization depends on individual anatomy and surgical goals.

Urethral lengthening is an option for those seeking the ability to urinate while standing, though it carries risks such as fistulas and strictures. This involves extending the native urethra using local tissue flaps or buccal mucosa grafts. While this enhances functionality, it requires meticulous precision to minimize complications. Some patients opt out of urethral lengthening to reduce these risks.

Phalloplasty Surgical Framework

Phalloplasty constructs a neophallus using autologous tissue grafts, typically from the forearm, thigh, or back. This approach provides increased phallic length, enabling individuals to meet aesthetic and functional goals. Donor site selection depends on vascular anatomy, tissue pliability, and scarring preferences. The radial forearm free flap (RFFF) is widely used due to its reliable vascular network and ability to preserve tactile sensitivity. The anterolateral thigh (ALT) flap offers a less visible scar but may require additional refinement procedures.

Microsurgical anastomosis connects donor site blood vessels and nerves to recipient areas, ensuring perfusion and sensory potential. This step is critical, as inadequate vascularization can lead to flap loss or poor healing. Nerve coaptation techniques involving the ilioinguinal and pudendal nerves help restore sensation. While immediate tactile perception is limited, gradual neural regeneration enhances sensation over months to years. Recovery varies based on individual neuroanatomy and surgical precision.

Beyond structural creation, functional considerations include erectile prostheses for penetrative capability. Since the neophallus lacks intrinsic erectile tissue, a semirigid or inflatable penile implant can be inserted in a secondary procedure after healing. Timing is crucial to minimize complications such as extrusion or mechanical failure, which occur more frequently in neophalloplasty than in cisgender penile prosthesis placement. Factors like tissue thickness, prosthetic anchoring, and scar maturation affect long-term durability and usability. Patients must weigh the benefits of added rigidity against infection and mechanical wear risks.

Neuroanatomical Factors For Sensory Function

Sensory restoration depends on peripheral nerve integration, neural plasticity, and vascular support. The ability to perceive touch, temperature, and pressure in a neophallus relies on successful nerve coaptation. The ilioinguinal, pudendal, and lateral femoral cutaneous nerves are commonly used, each contributing varying degrees of sensation. Sensory return takes months to years as neural regeneration progresses through Wallerian degeneration and axonal sprouting.

Nerve regeneration follows a predictable trajectory, with axons growing about 1 mm per day. For a neophallus with nerve grafts spanning 10 cm, initial sensation may emerge around 100 days post-surgery. During this period, patients often experience tingling or hypersensitivity as nerve fibers reconnect. The density of mechanoreceptors, such as Merkel cells and Ruffini endings, influences tactile feedback quality. Surgical precision in nerve alignment determines whether sensation remains localized or diffuses unpredictably.

Neural plasticity plays a role in long-term sensory refinement. The somatosensory cortex undergoes cortical remapping in response to new sensory inputs, a process seen in post-amputation studies where adjacent neural territories expand into denervated regions. In genital reconstruction, this reorganization shapes sensory interpretation. Some individuals report phantom sensations or altered perception early in recovery, which stabilizes as the brain adapts. Younger patients often exhibit stronger neuroplastic responses due to greater synaptic malleability.

Urethral Reconstruction

Urethral reconstruction in masculinizing genital surgery requires precise techniques to create a functional urinary conduit while minimizing complications like strictures and fistulas. The procedure extends the native urethra through staged or single-stage techniques, depending on anatomy and patient goals. Tissue selection is crucial, with local genital flaps and buccal mucosa grafts commonly used. Buccal mucosa is particularly advantageous due to its vascularization, infection resistance, and elasticity.

Maintaining an unobstructed lumen and adequate blood supply is essential to prevent ischemic complications. Vascular integrity is a primary concern, as poor perfusion can lead to necrosis and strictures. Multi-stage reconstruction reduces complication rates by allowing tissues to heal between surgeries, though it extends recovery. Single-stage techniques are quicker but carry a higher risk of complications, especially when extensive grafting is required.