Partial and Total Maxillectomy

Partial and Total Maxillectomy

Michael J. Odell and Patrick J. Gullane

The maxilla articulates with the bones of the skull base, and therefore maxillary surgery is occasionally performed to provide exposure for treatment of skull base pathology. This chapter, however, will focus on surgery for pathology that involves the maxilla primarily.
Squamous cell carcinoma and salivary tumors are generally responsible for the majority of cases requiring extirpative maxillary surgery.

The choice of imaging modality should be guided by the differential diagnosis. In general, evaluation of bony involvement is best accomplished with computed tomography (CT), and the extent of soft tissue involvement is better delineated by magnetic resonance imaging (MRI). For complete radiologic evaluation of complex lesions, CT and MRI should be included in the assessment. The radiologic appearance of the tumor often assists in the differential diagnosis. For odontogenic lesions, dental imaging (either plain films or CT dentascan) can provide valuable information. CT and MR angiography have largely replaced conventional angiography as a diagnostic entity for those cases requiring endovascular therapy.
An appropriate metastatic workup should be undertaken in patients who have been diagnosed with a malignant tumor. In general, this should include imaging of the regional lymphatics and chest. A diagnosis of secondary malignancy should initiate a search for the primary lesion.

Several incisions have been used to facilitate the variety of surgical procedures encompassed by the term maxillectomy. The different types of incisions are based on three fundamental but competing principles of exposure, function, and cosmetic outcome. The incisions used for a maxillectomy can be simplified by dividing them into external and internal incisions (Table 34-1).

Figure 34–1 Lateral rhinotomy.

The lateral rhinotomy utilizes the anatomical nasal subunits to provide excellent cosmetic and functional results. The incision (Fig. 34–1) begins midway between the medial canthus and dorsum of the nose, follows the lateral aspect of the side wall inferiorly, and continues around the alar rim, ending within the nostril.
Although the lateral rhinotomy approach provides adequate exposure for limited resections, more comprehensive maxillectomies require greater exposure. This can be accomplished three waysa:
1. Extending the incision inferiorly through the lip along the philtrum to allow elevation of a cheek flap, creating the Weber-Ferguson incision (Fig. 34–2)
2. Extending the incision superiorly to the medial end of the eyebrow (Lynch extension) (Fig. 34–3), with elevation of the medial canthal ligament and division of the nasolacrimal duct
3. Extending the incision laterally below the lower eyelid, above the upper lid, or both (Fig. 34–4)

These extensions can be combined, and almost all types of maxillectomy can be performed via this approach and its variations.

The majority of limited infrastructure maxillectomies can be performed via a perioral route without using an external incision. The placement of the intraoral incision is determined by the extent of the tumor resection, but it requires adequate labial and cheek retraction for exposure and appropriate osteotomies for en bloc tumor extirpation.

Figure 34–2 Lateral rhinotomy with Lynch extension. A small W-plasty is incorporated at the medial canthal level to minimize webbing.

Figure 34–3 Weber-Ferguson incision. The arrow demonstrates lip-splitting incision.

Figure 34–4 Weber-Ferguson incision with supra- and subciliary incisions.
The midface degloving approach described by Casson et al.1 has been applied to almost all forms of maxillectomy. This approach involves extended sublabial and gingivobuccal incisions, a septal transfixion incision, an intercartilaginous incision, and a pyriform aperture incision. It allows the soft tissue of the midface to be separated from the maxillae and therefore provides excellent bilateral maxillary exposure. The major advantage of this approach is that it avoids a facial incision; however, it is technically more demanding than the transfacial approaches. Vestibular stenosis may result from the circumferential vestibular incision and may result in a significant functional complication.

There is no uniform approach to maxillary surgery for resection of benign or malignant tumors. The extent of surgery and thus the approach are determined by each patient’s particular pathology. In general, a limited maxillectomy involves resection of one wall; a subtotal maxillectomy has two walls resected, and a total maxillectomy has all walls of the maxilla resected.

Jun 14, 2016 | Posted by admin in OTOLARYNGOLOGY | Comments Off