Medial Maxillectomy

History

• Small intranasal tumors are often completely asymptomatic or mimic more common benign conditions such as chronic sinusitis, allergy, or nasal polyposis.

• Common symptoms include nasal obstruction, “sinus pressure” or pain, nasal discharge that may be bloody, epistaxis, or anosmia.

• Failure of these symptoms to respond to adequate medical therapy or the presence of unilateral signs and symptoms should alert the physician to the possibility of malignancy and warrants further investigation by high-resolution imaging.

• Orbital symptoms such as tearing, double vision, or proptosis are a concern for malignancy with extension to the orbit.

Physical Examination

• Comprehensive examination of the nasal cavity should be done after topical decongestion and anesthesia using rigid or flexible endoscopy ( Fig. 106.1 ). The presence of intranasal masses, ulcers, or areas of contact bleeding may suggest a malignant tumor. Although unilateral “polyps” may be inflammatory, they are more commonly neoplastic.

  

• Tumors may also present as a submucosal mass without changes in the mucosa.

• Any suspicious lesions should be biopsied, preferably after high-resolution imaging has been obtained, to avoid severe bleeding from highly vascular tumors and/or cerebrospinal fluid (CSF) leak in cases of intracranial extension.

• Extension of sinonasal tumors to adjacent structures renders the diagnosis obvious but is a late manifestation of the disease. Soft tissue swelling of the face may indicate tumor extension through the anterior bony confines of the nose and sinuses. Inferior extension toward the oral cavity may present with an ulcer or a submucosal mass in the palate or the alveolar ridge. Middle ear effusion may indicate tumor involvement of the nasopharynx, Eustachian tube, or tensor veli palatini muscle. Extension of the tumor to the skull base may lead to involvement of the cranial nerves producing anosmia, blurred vision, diplopia, or hypothesia along the branches of the trigeminal nerves.

• Orbital involvement is common in patients with cancer arising from the ethmoid, maxillary sinuses, or the nasal cavity. Epiphora usually indicates involvement of the nasolacrimal duct. Diplopia may result from compression or infiltration of ocular nerves or muscles. Proptosis may be the result of displacement or invasion of the globe. Visual loss secondary to optic nerve involvement is usually a late sign, although more subtle signs of optic nerve dysfunction, including afferent pupillary defect, loss of color vision, and visual field defects, are more frequently encountered. Finally, orbital involvement may be asymptomatic and is only discovered on computed tomography (CT) or magnetic resonance imaging (MRI) evaluation of patients with sinonasal complaints.

• The presence of a mass in the neck usually represents metastatic cancer to the cervical lymph nodes.

Imaging

• Imaging is very helpful in obtaining pretreatment information regarding the location, size, and extent of the primary tumor, as well as the presence of regional and distant metastasis. Such information is critical in deciding on therapeutic options and for proper preoperative planning of the optimal surgical approach.

• Both CT and MRI might be needed for optimum radiologic assessment of sinonasal malignancy, particularly in assessing the cranial base, orbit and pterygopalatine, and infratemporal fossae. Coronal images best delineate involvement of the orbital walls and invasion of the skull base, particularly the cribriform plate. Axial images are particularly helpful in demonstrating tumor extension through the posterior wall of the maxillary sinus into the pterygopalatine fossa and infratemporal fossae. Sagittal images are particularly helpful in evaluating extension along the cribriform plate, planum sphenoidale, and clivus.

• The main advantage of CT scans is in delineating the architecture of the bones, especially in “bone windows.” The addition of contrast enhancement increases tumor definition from adjacent soft tissue, especially intracranially. Bone destruction and invasion of soft tissue suggest an aggressive lesion, usually a malignant neoplasm. Widening or sclerosis of the foramina of the infraorbital, Vidian, mandibular, or maxillary nerves may indicate perineural spread.

• MRI with its superior soft tissue contrast and multiplanar capability is superior to CT in pretreatment evaluation of primary malignant tumors of the sinonasal cavity. MRI is unsurpassed in delineating soft tissue detail, both intra- and extracranially. Obliteration of adipose tissue planes in the pterygopalatine fossa, infratemporal fossa, and nasopharynx usually indicates tumor transgression along these boundaries. Dural thickening or enhancement is usually an indication of tumor involvement, and evaluation of critical structures such as the brain and carotid artery is best delineated by MRI. Similarly, enhancement or thickening of cranial nerves suggests perineural spread, which is better detected on MRI than CT. Perhaps one of the most significant advantages of MRI is the ability to distinguish tumor from retained secretions secondary to obstruction of sinus drainage ( Fig. 106.2 ).

  

• Angiography is not indicated in the routine assessment of patients with neoplasms of the nose and paranasal sinuses. In certain selected cases, however, angiography may be necessary. These cases include vascular neoplasms of the sinonasal region such as juvenile angiofibroma, where angiography will not only delineate the tumor extent and the blood supply but also permit the use of selective embolization of the vascular supply to the tumor. This reduces intraoperative blood loss, facilitating surgical resection.

Indications

• 1.

  Medial maxillectomy is indicated for resection of tumors of the lateral nasal wall, nasal cavity, nasal septum, or the medial wall of the maxillary sinus.

• 2.

  Medial maxillectomy may also be used for exposure of and access to the pterygopalatine fossa, pterygoid plates, nasopharynx, sphenoid sinus, clivus, and the medial infratemporal fossa.

• 3.

  Medial maxillectomy can be combined with resection of the floor of the nose, palate, or upper gingiva (inferior maxillectomy).

• 4.

  Medial maxillectomy may also be combined with a transcranial approach for resection of the anterior skull base.

Contraindications

Medial maxillectomy is not adequate if the tumor extends laterally to the infraorbital nerve, palate, or facial soft tissue.

Preoperative Preparation

• A thorough preoperative assessment should determine the candidacy of a patient for surgical management of his or her neoplasm. This involves a careful “mapping” of the tumor extent, as well as the patient’s general medical condition and functional status.

• This is usually accomplished by a detailed history and a comprehensive examination of the head and neck region including sinonasal endoscopy.

• Examination of the cranial nerves as well as ophthalmologic evaluation should be done to evaluate the cranial base and orbital extension, respectively.

• Evaluation by a maxillofacial prosthodontist is required in most patients to obtain preoperative dental impressions and to design surgical obturators or splints for maintenance of proper dental occlusion and oral rehabilitation.

• Consultations with medical and radiation oncology colleagues should be done to consider incorporation of chemotherapy or radiation in the treatment plan. Radiation and/or chemotherapy may be used preoperatively as induction (neoadjuvant) or postoperatively as adjuvant therapy. Such decisions are best discussed in the format of a multidisciplinary tumor board.

• If surgery is chosen as a treatment modality, the plan for the surgical approach, the extent of resection, and reconstructive options should then be formulated.

• Careful assessment of the patient’s general medical condition should be carried out prior to surgery. Preoperative chest radiograph, blood counts, liver and renal function tests, blood sugar, electrolytes, coagulation studies, and an electrocardiogram (ECG) should be performed routinely. Appropriate consultations from internal medical colleagues should be obtained in order to optimize the patient’s medical status before surgery and help in the postoperative management.

• Finally, the surgical team should discuss with the patient and the family the nature of the disease, the evaluation, and the indications, risks, possible complications, sequelae, and any alternative plans of management. The expected postoperative course including length of stay in the hospital, feeding, rehabilitation, and the need for adjuvant therapy should be described. This ongoing communication should be maintained in a clear, honest, and sympathetic fashion throughout the course of the patient’s care.