Functional reconstruction of forehead with microneurovascular transfer of attenuated and broadened gracilis muscle

Gracilis free flap in head and neck reconstruction beyond facial palsy reanimation

INTRODUCTION

The gracilis muscle free flap has gained popularity in head and neck reconstruction due to minimal donor-site morbidity, reliable vascular pedicle, strong muscular component, and possibility to perform nerve coaptation. However, almost all the existing evidence in the literature is related to its use for facial palsy reanimation. The aim of this study was therefore to review and provide a comprehensive summary of all the possible indications and outcomes of this versatile free flap in head neck reconstructive surgery.

MATERIALS AND METHODS

A systematic review of the literature was conducted including articles from 1970 to 2019. All articles were examined and described.

RESULTS

Twenty-seven papers published between 1994 and 2019 were identified for analysis. The evidence highlights the use of the gracilis muscle free flap for parotid, forehead and midface defects, oral tongue, oral sphincter, lower and upper lip, cheek, and oral commissure defects, among others, as the most common defects reconstructed.

CONCLUSION

This flap represents an easy to harvest and versatile free flap with low donor-site morbidity and multiple proven uses in head & neck reconstruction. We therefore encourage reconstructive surgeons to include this flap in their armoury, either as a first or as a second-line option.

Detailed Neurovascular Anatomy of the Serratus Anterior Muscle: Implications for a Functional Muscle Flap with Multiple Independent Force Vectors

A functional muscle free flap with multiple muscle segments that could be oriented independently to produce different force vectors would be beneficial in facial reanimation and upper extremity reconstruction. The serratus anterior muscle has this potential because two or more individual muscle slips can be transferred on a single vascular pedicle. Although serratus anterior muscular anatomy has been studied previously, little attention has been given to the intramuscular anatomy. Muscle slips 5 through 9 (and 10, if present) in 50 specimens from 27 cadavers were studied following intraarterial latex injection. Eight specimens were injected with a radiopaque material (latex/diatrizoate/lead mixture) for x-ray delineation of the intramuscular vascular pattern. Slips 5 through 9 are consistently supplied by a single dominant branch of the thoracodorsal artery and innervated by the long thoracic nerve. Dissection revealed that the long thoracic nerve and its branches invariably follow the artery and divide proximal to the corresponding arterial division. There is a consistent vascular pattern to each muscle slip, in which the serratus artery gives rise to common slip arteries, each of which supplies adjacent muscle slips. The mean length of a muscle slip from its origin on the rib periosteum to the division of the common slip artery is 9.6 cm. These findings imply that the slips may be separated to the level of these common slip arteries, with up to five slips transferred on a single neurovascular pedicle and each slip oriented independently to provide multiple muscle force vectors. With these possibilities, the reconstructive surgeon may be able to restore more natural facial animation and better intrinsic muscle function in the upper extremity.

Application of dermal substitute (Integra) to donor site defect of forehead flap

Although forehead flap has limited use, it may have a role as a 'third' line option. Its primary complication is the poor cosmetic defect on the forehead. A case is presented in which, after harvesting the flap for reconstruction of the oral cavity, a dermal substitute (Integra) together with split thickness skin graft was used for the management of this wound. The result was significantly improved over using split skin graft alone.