The accuracy of duplex ultrasonography in the planning of skin flaps in the lower extremity.

Abstract

The septocutaneous perforators represent one of the major sources of the blood supply to the skin of the lower extremity. Despite several well-described anatomic accounts, the location of lower leg septocutaneous perforators, as they originate from each of the three main infrapopliteal vessels in the leg, remains inconsistent as a result of individual anatomic variations. With the aid of duplex ultrasonography (color Doppler imaging), preoperative, mapping and size determination of these perforators can be provided. The skin paddle can then be designed to lie exactly over these perforators, ensuring blood supply to the skin paddle. The location and distribution of medial septocutaneous perforators in the leg, which originate from the posterior tibial artery, were mapped using anatomic dissections (29 lower extremities). These findings were then compared with duplex ultrasonographic data in 9 living volunteers (18 lower extremities). The medial septocutaneous perforators were chosen for this study because they course directly over the posterior tibial artery, making their location difficult to assess with standard Doppler techniques. The hand-held Doppler is incapable of distinguishing flow originating from the perforators versus the posterior tibial artery. No significant difference existed between cadaver and duplex distributions. "Large" perforator vessels (> 1 mm outer diameter) were evenly distributed with a central tendency at 140 to 150 mm from the medial malleolus. The distribution of "small" perforator vessels (< 1 mm outer diameter) was skewed. Fifty percent were found within 80 mm of the medial malleolus and the remainder spread proximally in the leg.(ABSTRACT TRUNCATED AT 250 WORDS)