Anterolateral thigh perforator flap: varying perforator anatomy.

The anterolateral thigh (ALT) perforator flap is based on the septocutaneous or musculocutaneous perforators from the lateral circumflex femoral vessels. Each perforator artery should be accompanied by 2 veins. Anomalies of the perforator anatomy in the subfascia and intramuscular layer are rarely reported. This study analyzed 6 anatomic perforator variations from subfascial to intramuscular level out of 1043 ALT perforator flaps performed from 2005 to 2007 in China Medical University Hospital in Taichung, Taiwan and from 2004 to 2007 in E-Da Hospital in Kaohsiung, Taiwan. The perforator flaps included (1) 1 perforator artery and 4 accompanying veins, (2) 1 perforator artery and 1 accompanying vein, (3) 1 tortuous perforator artery and 1 accompanying vein, (4) 1 perforator artery with no accompanying vein, (5) 2 veins with no accompanying perforator artery, and (6) 1 vein only. These variations in perforator anatomy were believed to be the causes of total or partial flap failure after excluding all the other possibilities such as vessel kinking or perforator injury during intramuscular dissection. Further, the nearby anteromedial thigh or tensor fasciae lata flaps were considered alternative flaps in cases of unusual perforator anatomy. The contralateral ALT flap was also necessary in some cases. However, anatomic variations in perforators from subfascial to intramuscular layer must be considered if the flap is to be used safely and reliably.