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Page 2 of 11 Yamakawa et al. Plast Aesthet Res 2020;7:24 I http://dx.doi.org/10.20517/2347-9264.2020.20

INTRODUCTION
Soft tissue defects of the dorsal hand are commonly caused by relatively high-energy trauma such as
industrial accidents. In such cases, free vascularized flap transplantation is the ideal procedure because
the major vessels in the zone of injury that may have been damaged, and the vascular supply of the flap
[1]
and affected limb can be reconstructed using a flow-through method . Although free flap surgery has
advanced, not all surgeons can select this complicated procedure. Recently, several surgeons have reported
[2,3]
local flap procedures for the reconstruction of dorsal hand defects . Among them, the reverse radial
[4]
forearm flap is a common method for the treatment of dorsal hand injuries . This flap is reliable in regards
to vascular supply; however, the main vessels of the forearm and hand must be sacrificed. Thus, this
flap cannot be used, if Allen’s test shows an incomplete palmar arch. Moreover, unacceptable donor site
morbidity is a major drawback of this flap. The posterior interosseous flap is also an effective option .
[5,6]
Although this flap enables covering the dorsal hand defect with well-vascularized tissue without sacrificing
major vessels, it requires surgeons to perform fine and burdensome procedures. The radial artery perforator
based adipofascial flap is a versatile flap that is safe and easy to elevate without sacrificing the radial
artery . In addition, elevating it as an adipofascial flap enables surgeons to avoid an unacceptable donor
[7,8]
scar. We present two case reports demonstrating the usefulness of this pedicled perforator flap for dorsal
hand reconstruction.

ANATOMY AND PREOPERATIVE EVALUATION
Before flap elevation, contrast-enhanced computed tomography and/or color Doppler ultrasonography of
the affected forearm were performed to evaluate the blood circulation of radial vessels. Using color Doppler
[9]
ultrasonography, Onode et al. reported that an average of six fasciocutaneous perforators arising from
the distal radial vessels can be observed within 15 cm proximal to the distal wrist crease. There are two
or more clinically significant (> 0.5 mm) cutaneous perforators at the pivot point within 2 cm proximal
[8]
to the radial styloid . The adipofascial flap on the lateral aspect of the distal forearm is raised proximal
to distal, including the lateral antebrachial cutaneous nerve and the cephalic vein. Although a number of
surgeons have reported using this flap, there is no consensus regarding the maximum safe longitudinal
flap size. In our opinion, it can be the length of the forear, because as Taylor et al. reported, designing
[10]
the flap in the longitudinal direction along the cutaneous nerve and the cutaneous vein, blood circulation
of a perforasome composed of multiple perforators connected to each other by a true anastomosis can be
stabilized. Therefore, including the lateral antebrachial cutaneous nerve and the cephalic vein within the
flap enables the distal perforator-based adipofascial flap to be applied safely [Figure 1A and B].

SURGICAL PROCEDURE OF RADIAL ARTERY PERFORATOR-BASED ADIPOFASCIAL FLAP
TRANSFER
1. Design a rectangular adipofascial flap along the radial artery sufficient to cover the defect. An S-shaped
skin incision is favorable in consideration of the convenience of fascial flap dissection and direct closure of
the skin [Figure 2A].

2. Dissect the subcutaneous plane sufficiently deep to avoid skin necrosis, leaving the dorsal forearm
cephalic vein on the adipofascial flap.

3. After incising the proximal edge of the adipofascial flap, dissect the sub-fascial flap from the proximal to
distal direction. Several perforators arising from radial vessels can be found in the distal one-third of the
forearm. Next, elevate the flap through the intertendinous septum in the middle of the flexor carpi radialis,
abductor pollicis longus, and brachioradialis tendons, and enter the fascia of the forearm. Under direct
observation, at least one perforator entering the flap must be preserved around the styloid, which is a pivot
point [Figure 2B].