Reconstruction of Lower Lip with Innervated Serratus Anterior Muscle Flap

Introduction: Main principle in reconstruction of lower lip, like in other tissues, is to reconstruct the defect by using similar tissues. In cases where defect is more than ⅔ of lower lip, reconstruction with local tissues causes microstomia. Although reconstruction of upper and lower lips with functional gracilis muscle flap, which was first performed by Burt, has been used in lip reconstruction of 13 patients in total by different authors (1, 2); no other functionally used flap has been encountered when reviewing the literature. Here are presented four cases in which patients underwent wide lower lip reconstruction due to squamous cell carcinoma, and in which we performed lower lip reconstruction with innervated serratus anterior muscle flap.

Methodology and Material: Here are presented four cases in which patients underwent wide lower lip reconstruction due to squamous cell carcinoma, and in which we performed lower lip reconstruction with innervated serratus anterior muscle flap. Four of the patients were male, and one female; and average length of follow up was 14.5 months (12-18 months). Neck scan was performed for all patients, and supraomohyoid neck dissection was performed in one patient after invasion was detected in sentinel lymph node biopsy. Eighth slip of serratus anterior muscle, which was planned in the size of defect in lower lip, was elevated to subscapular artery origin. Segmental nerve was included in the flap. In the receiver area, veins were anastomosed end to end to facial artery and vein; and nerve to marginal mandibular nerve. Oral mucosa and front face of the flap was covered with split thickness skin graft.

Results: One of the patients deceased of myocardial infarction one month after the surgery. Another patient had flap loss due to venous thrombosis of the flap. Oral competence was achieved in two patients with successful results. In results from one year postoperative EMG, compound muscle action potentials which indicate the existence of regeneration were detected.

Conclusions: Functional reconstruction with serratus anterior free flap in repairing wide full-thickness defects of lower lip is an effective and successful method which may yield extremely satisfactory results.