Anatomical study of perforator arteries in the distally based radial forearm fasciosubcutaneous flap.

We investigated the anatomical vascular basis of the forearm fasciosubcutaneous flap (FSC-F), fed by the distal perforator arteries of the fascia. This type of flap was proposed, in hand reconstructive surgery, to avoid the disadvantages caused by axial-pattern reverse radial forearm fasciocutaneous flap, based on ligation and rotation of the radial artery (RA). In eight fresh cadaveric forearms, the RA was injected slowly with acrylic resin and the superficial flexor compartment was dissected. Then the FSC-F was raised from the lateral margins of the sample to the median RA axis, and the collaterals of the RA (number, interval of origin, and caliber) were evaluated. The fascial branches of RA (mean number +/- SD: 20 +/- 3) originated mainly from the radial and ulnar sides of the RA. In the distal forearm the vessels were more numerous (mean value = 11.3 vs. 8.9; Student's t-test, P < 0.05) but smaller in diameter (mean value = 0.45 mm vs. 0.63 mm; Student's t-test, P < 0.05). The perforator arteries forked in a T-shape following the main axis of the forearm and anastomosed in the fascial plane, forming longitudinal fan-shaped arterial chains giving rise to the vascular epifascial network. Histological (hematoxylin-eosin, azan-Mallory, Weigert) and immunohistochemical (anti-von Willebrand factor) study of the FSC-F at different levels of sampling was also carried out. The epifascial branches of distal sections were smaller in diameter (78.3 +/- 35.5 microm) than those of intermediate (105.7 +/- 28.7 microm; Newman-Keuls test, P < 0.01) and proximal (116.8 +/- 31.2 microm; Newman-Keuls test, P < 0.001) sections. Our findings indicate that the perforator arteries and epifascial branches are smaller in the distal forearm, so that during surgical dissection, the safety distance from the radial styloid should take into account that also in the presence of a sufficient number of vessels in the distal forearm their caliber could be inadequate to the hemodynamic request of the flap. Thus, rather than on a theoretic distance from the radial styloid, the length of the flap should be based on an accurate evaluation of the individual vascularization of the forearm case by case.