Maneuvers to Aid Raising and Survival of the Homodigital Island Flap.

Sir:

The homodigital island flap can be used to cover small soft-tissue defects. Many authors[1,2] have described the technical steps with regard to the elevation of this island flap and have discussed the importance of preserving the adipofascial tissue around the digital artery. This approach avoids problems with venous congestion and thus flap loss.

In Lai’s[2] original description of the reverse homodigital island flap, the digital artery is first identified and then dissected free from the digital nerve. In our experience, it can often be difficult to identify the digital artery first, particularly in pediatric cases, even when the digit is not fully exsanguinated. Furthermore, this approach can risk damaging the venous plexus, which is incorporated in the adipofascial tissue surrounding the artery. The surgeon may inadvertently skeletonize the digital artery in their search, which may jeopardize flap survival.

Approaching the flap pedicle in a different manner can provide the solution to these challenges. Figure 1 illustrates the approach in a proximally based homodigital island flap in a pediatric case. The same technique can apply to the reverse homodigital flap. After incision over Lai’s line (dorsal and volar skin junction), the digital nerve should be the first structure identified, rather than the artery. The digital nerve is easy to locate because of its pearly white consistency and the presence of Pacinian corpuscles. It is then dissected free from the adipofascial tissue that houses the digital artery.

Fig. 1.

Pediatric case illustrating identification of digital nerve first, which is dissected free from underlying adipofascial tissues.

Once the nerve is dissected free, the flap can then be detached without interfering with the adipofascial tissues. This also speeds up the raising of the pedicle as one does not need to extensively search for the digital artery. The flap is finally inset with loose stitches, and care is made not to tightly close over the adipofascial tissue as this may compromise venous return (Fig. 2).

Fig. 2.

Flap inset with loose stitches and small area over adipofascial tissue left open.