GRACILUS MYOCUTANEOUS FLAP: ARTERIAL SUPPLY AND SKIN COVER

Abstract

Purpose of the study: Surgical reconstruction procedures using the gracilus myocutaneous flap may be compromised if partial or total necrosis of the skin cover develops. The purpose of this study was to describe the anatomic blood supply to the gracilus muscle and the corresponding skin cover in an attempt to better understand the arterial afferences to the skin and define the safest topography for a transferable zone of skin.

Material and methods: We dissected the thighs of human adult cadavers to detail the vascular bundles feeding the gracilus muscle.

1. Selective injections of methylene blue were used in the main gracilus pedicle; the area of skin colored was then measured (greatest and smallest diameter) for computation of the surface area using an imaging software.

2. Selective injection of a colored latex fluid enabled description of the perforating vessels between the muscle body and the skin cover.

Results: Preliminary results of nine dissections showed that the main blood supply of the gracilus muscle arose from the deep femoral artery (n=8 dissections) or the common femoral artery (n=1 dissection) then penetrated the muscle 90.55 mm below the pubis with a mean diameter of 1.32 mm. The muscle was fed by one to four accessory arteries. The skin cover was stained in all cases, the area involved lying over the proximal and mid thirds of the muscle. The surface area was irregular, the mean length being 127.5 mm and the mean width 91.66 mm. The computed surface area was 88.08 cm² on average (range 58–120.95 cm²). Each muscle had two to six perforating vessels issuing from the opposite side of the main pedicle and comprised within a 48 mm long segment before dividing at the subcutaneous level. A mathematical model correlated the skin surface area to the number of perforating arteries.

Discussion and conclusion: Our findings suggest it would be possible to determine the surface area of skin transferable with a gracilus muscle flap based on high-frequency duplex-Doppler assessment of the number and position of the perforating arising from the muscle and feeding the skin surface. The linear distribution of the surfaces measured as a function of the number of perforating arteries suggests that more reliable conditions for gracilus myocutaneous flap harvesting could be proposed to minimize the risk of cutaneous necrosis.