Thoracodorsal nerve graft for reconstruction of facial nerve branching

Abstract

Object: Surgical treatment of parotid malignancies may frequently involve facial nerve amputation to achieve oncological radical resection. The entire facial nerve branching from its exit from the stylomastoid foramen to the periphery of the gland is often sacrificed. The first reconstructive strategy is the immediate reconstruction of the facial nerve by directly anastomosing the trunk of the facial nerve to its distal branches by interpositional nerve grafting. The present study was performed to determine the adequacy of thoracodorsal nerve grafting for immediate repair of the facial nerve. The anatomical features of the thoracodorsal nerve make it particularly appropriate to match its trunk to the stump of the facial nerve at its exit from the stylomastoid foramen. Up to seven branches of the thoracodorsal nerve may be distally anastomosed to the severed distal branches of the facial nerve. More complex reconstruction may be addressed simultaneously by contemporary harvesting a de-epithelialized free flap from the same site based on thoracodorsal vessel perforators and preparing a rib graft from the same donor site.

Methods: Between October 2003 and August 2010, seven patients affected by parotid tumors (6 with parotid malignancies and 1 with multiple recurrences of pleomorphic adenoma) underwent radical parotidectomy with intentional sacrifice of the facial nerve to obtain oncological radical resection. In all patients, the facial nerve was reconstructed with an interpositional thoracodorsal nerve graft. In four patients, a de-epithelialized free flap based on the latissimus dorsi was transposed to cover soft tissue defects. Moreover, two of these patients also required a rib graft to reconstruct both the condyle and ramus of the mandible. With the exception of one patient affected by recurrent pleomorphic adenoma, all patients underwent radiotherapy after surgical treatment.

Results: All patients in our study recovered mimetic facial function. Facial muscles showed clinical signs of recovery within 5-14 (mean: 7.8) months, with varying degrees of mimetic restoration, and almost complete facial symmetry at rest in all patients. The House-Brackmann final score was I in two patients, II in two patients, and III in three patients.

Conclusions: A thoracodorsal nerve graft to replace extratemporal facial nerve branching is a valid alternative technique to multiple classical nerve grafts, with good matching at both the proximal and distal anastomoses.

Keywords: Facial nerve reconstruction; Radical parotidectomy; Thoracodorsal nerve.