Anatomic and magnetic resonance imaging bases for the naso-maxillo-cheek flap technique.

A transfacial approach to the deep cranio-maxillo-facial areas by the naso-maxillo-cheek flap technique (NMCF) is indicated for the treatment of some bulky tumors of the naso-pharynx. The procedure requires precise preoperative imaging. This study presents the morphologic bases of this surgical access and the reasonable limits of the excision preoperatively determined by magnetic resonance imaging (MRI). 18 facial and skull specimens were submitted to surgical facial dismantling by the NMCF technique according to Curioni's method. The clinical application in a 66-year-old patient suffering from a neuroblastoma of the olfactory nerve extended into the naso-pharynx is presented. Pre- and postoperative MRI correlations were made in transverse, sagittal and frontal acquisitions. Several structures were preserved in the procedure: facial reliefs, inferior orbital rim and orbital floor, posterior wall of the maxillary sinus covering the pterygopalatine fossa, lateral and medial pterygoid plates and pterygopalatine ganglion with its branches, lateral facial neurovascular pedicle, teeth and soft palate. Other structures were sacrificed: arteries and nerves located at the sites of skin and mucosal incision, and at the sites of osteotomies, ie the infraorbital nerve, the distal part of the greater palatine nerve, the nerves supplying the naso-pharynx, the nasal septum and the nasal conchae, nasolacrimal groove and lacrimal canal. The NMCF technique gives wide access to the deep nasal and nasopharyngeal areas. It is essential to preserve the lateral facial neurovascular pedicle to prevent necrosis of the midface structures. Preservation of the bony architecture surrounding the osteotomy sites is of great importance to allow precise final bone reassembly. Preoperative MRI appears of paramount importance to determine the borders of the lesion and the possibility of block resection.