What is Phaloplasty: ALT (anterior lateral thigh) flap?

Advances in modern surgical techniques allow us to fully reconstruct the male genitalia, using tissue from other parts of the body. Most generally accepted techniques today are the radial flap and the ALT flap. In the first case, the skin and tissue are harvested from the forearm and microsurgically transferred to the genital area. This method has many advantages and can be applied to some of our patients; however, our method of choice is the ALT flap, which is harvested from the thigh. When comparing the two methods, equally aesthetically pleasing and functional results can be achieved. The radial flap requires longer operating time and longer recovery and has a higher risk of total flap failure, if one of the many microsurgical connections fail. Also, the scar on the forearm is very visible, marking the donor area permanently. In contrast, the ALT flap can be performed faster and safer, while the scar is concealed by garments or can even be completely removed when desired.


Prior to phalloplasty, a colpectomy (removal of the vaginal vulva) in combination with a metoidioplasty or lengthening of the urethra are performed. The ALT phalloplasty itself is performed under general anesthesia and can be carried out as a single procedure or staged in two steps. In order to identify and evaluate the vessels of the flap, a CT-scan is performed before the procedure. In thin patients, the inner layer of the urethra is reconstructed directly from the ALT flap, while in thicker flap, a secondary urethral flap from the groin is used to reconstruct the inner cylinder of the urethra. To better understand the procedure, it can be broken down to the following steps:
1. Harvesting the ALT flap: After having identified the vessels with doppler and the Angio-CT scan, the ALT flap is raised, maintaining the dominant vessel.
2. Nerve preparation: the superficial femoral nerve is maintained in the flap and prepared for further connection later.
3. Vessel preparation: the dominant vessel is followed down to its origin from the femoral artery, freed from side branches.
4. Flap rotation: the flap is carefully tunneled to the genital area, maintaining the original vessels. If the length of the vessels is too short, a microsurgical vessel loop is used.
5. Nerve anastomosis: the superficial femoral nerve of the flap is connected to the clitoral and pelvic nerves
6. Inner cylinder: either portion of the ALT flap or a second groin flap are wrapped around the urethral catheter and connected to the previously elongated urethral opening.
7. Outer cylinder: the ALT flap is wrapped around the urethra creating the penile shaft. The glans penis is either formed at this time or at a later stage.


After the procedure, the flap is monitored frequently in order to avoid blood supply failure and patients are mobilized after the second day. The urethral catheter remains for 2-6 weeks, until the healing process is complete. Further surgical procedures such as erectile implants can be performed after one year.


The ALT phalloplasty has many advantages and is the golden standard in our clinic. The penis is of adequate length, since the flap can be harvested up to 20cm length. Sensation is very adequate and can in some cases even stimulate orgasms. The flap itself is very stable and can support any kind of penile prosthetic. Urinating in a standing position is possible. The downtime compared to a radial flap is relatively low and the success rate higher.

All penile reconstruction techniques available today achieve a modest result, but still have imperfections. We advise all our patients to consider wisely if and what type of phalloplasty they need, explaining all the up and downsides of each individual surgery. When deciding to undergo a phalloplasty, one must consider that future complications may lead to functional problems which might require further surgical care.