Abstract
The technical aspects of the medial maxillectomy procedure have evolved over the last century to include modifications that permit improved cosmesis and patient morbidity. Following the adoption of endoscopic sinus surgery in the 1980s, there was a paradigm shift toward using endoscopic techniques for resecting select cases of benign and malignant tumors. The modified medial maxillectomy keeps the nasomaxillary buttress and nasolacrimal system intact as well as the anterior head of the inferior turbinate to avoid empty nose syndrome and chronic epiphora. The technique has also been adapted for recalcitrant maxillary sinusitis from chronic mucociliary dysfunction due to underlying genetic causes (e.g., cystic fibrosis and primary ciliary dyskinesia) or trauma (previously stripped sinus from Caldwell-Luc procedure). The modified medial maxillectomy improves access for clinic débridement, saline irrigations, and topical medical therapy.
Keywords
chronic maxillary sinusitis, endoscopic medial maxillectomy, endoscopic sinus surgery, inverted papilloma, medial maxillectomy, modified medial maxillectomy, recalcitrant maxillary sinusitis
Introduction
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The modified medial maxillectomy entails removing a large portion of the medial maxillary wall to gain wide access to the maxillary sinus. It is primarily used for the removal of benign tumors, such as inverted papillomas and juvenile nasopharyngeal angiofibromas.
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The modified medial maxillectomy can also be used to treat chronic maxillary sinusitis refractory to maximum medical management and standard maxillary antrostomy. Modified medial maxillectomy creates a wide opening into the maxillary sinus that may allow improved mucus clearance and better penetration of topical medication and lavages. This procedure can be used in the management of those sinuses in which infected secretions and mucin are persistently found in the floor or along the anterior wall and lateral wall of the sinus. Markedly enlarging the sinus will allow for improved distribution of nasal irrigation and easier access for in-office débridements and suctioning.
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This procedure is commonly used for chronic maxillary sinusitis associated with cystic fibrosis, biofilms, extensive allergic mucin, or polyps of the anterior wall and floor of the sinus.
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The procedure is also useful for treatment of chronic maxillary sinusitis caused by prolapsed orbital fat from previous medial orbital decompression surgery or inflammation from previous mucosal stripping from other sinus procedures (e.g., Caldwell-Luc).
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Modified medial maxillectomy differs from a traditional endoscopic medial maxillectomy by preserving the nasolacrimal duct and a portion of the inferior turbinate.
Anatomy
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The lateral nasal wall includes the inferior turbinate, infundibulum (with maxillary ostium), uncinate process, and nasolacrimal duct.
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The boundaries for a modified medial maxillectomy are the nasolacrimal duct anteriorly, the posterior maxillary wall posteriorly, the nasal floor and inferior turbinate medially, the lateral maxillary wall laterally, the agger nasi cell and lamina papyracea superiorly, and the maxillary sinus floor inferiorly ( Figs. 15.1 and 15.2 ).
Fig. 15.1
Schematic drawings in sagittal (A) and axial (B) views showing the region removed (shaded area) when a modified medial maxillectomy is performed.
Fig. 15.2
(A) Drawing showing the boundaries of a completed right modified medial maxillectomy. Dashed line represents the course of the nasolacrimal duct within the medial maxillary wall. The posterior boundary is the posterior maxillary wall (PMW). The superior boundary is the lamina papyracea. The inferior boundary is the maxillary sinus floor. The medial boundary is the inferior turbinate (IT) and nasal floor. The lateral boundary is the lateral wall of the maxillary sinus (LMW). (B) Endoscopic image showing a completed modified medial maxillectomy. MS, Maxillary sinus wall; NFMF, nasal floor mucosal flap.
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The nasolacrimal duct runs anteriorly in the bony lateral nasal wall and empties into the inferior meatus (Hasner valve) just inferior to the attachment of the inferior turbinate.
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The inferior turbinate spans the length of the nasal cavity. The majority of the maxillary sinus cavity lies inferior to the superior attachment of the inferior turbinate to the lateral nasal wall. Removal of the midportion of the inferior turbinate significantly improves exposure of the maxillary sinus.
Preoperative Considerations
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If pathology or inflammatory disease exists in other sinuses, these areas can be addressed before or after performing a modified medial maxillectomy depending on the indication or exposure.
Radiographic Considerations
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Study both the axial and coronal computed tomography (CT) scans.
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Identify the course of the nasolacrimal duct and its position in the lateral nasal wall.
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Identify the extent and origin of the tumor preoperatively so that appropriate instrumentation can be made available for adequate removal, including angled endoscopes, microdébriders, and drills.
Instrumentation
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0-degree and 30-degree endoscopes
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45-degree or 70-degree endoscope to remove allergic mucin or polyps along the anterior or lateral maxillary wall
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Curved and straight Beaver blades
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J-curette
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Suction Freer elevator
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Turbinate scissors
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Through-cut instruments (Blakesley, backbiting, side-biting)
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15-degree drill
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Small hemostat
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Suction Bovie electrocautery
Pearls and Potential Pitfalls
Pearls
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Raising a medially based mucosal flap off the floor of the nasal cavity allows complete coverage of the exposed bone of the inferior maxillary ridge and helps prevent postoperative crusting and contracture.
Potential Pitfalls
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Be sure that the remnant end of the inferior turbinate is cauterized adequately to prevent postoperative epistaxis from the posterolateral nasal branch of the sphenopalatine artery.
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Aggressive postoperative débridement of the posterior inferior turbinate remnant should be avoided for 2 weeks following surgery. There is an increased risk of postoperative epistaxis that can result from clot dissolution or débridement within this time period.
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If the nasolacrimal duct is resected, be sure that the duct is cut obliquely or opened with anterior and posterior flaps to prevent stenosis of the duct and postoperative epiphora.
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Avoid stripping maxillary sinus mucosa. Damage to the sinus mucosa can lead to extensive inflammation, poor mucociliary clearance postoperatively, and contracture of the maxillary cavity.
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If the operation is being performed to treat chronic maxillary sinusitis secondary to orbital fat herniation or prior medial orbital decompression, create the inferior and anterior maxillary wall bone incisions first to provide an endoscopic view of where the mucosalized fat fills the infundibulum. The medial maxillary wall can then be reflected away from the orbital fat in a lateral to medial direction, which helps avoid inadvertent orbital entry.
Surgical Procedure
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Inject 1% lidocaine with 1:100,000 epinephrine into the superior attachment of the middle turbinate, inferior turbinate, and medial maxillary wall. A sphenopalatine block may also be performed by injecting lidocaine with epinephrine transorally into the greater palatine foramen.
Step 1: Perform a Maxillary Antrostomy With Complete Removal of the Uncinate Process
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See Chapter 8 .
Step 2: Resect the Posterior Two-Thirds of the Inferior Turbinate ( Fig. 15.3 )
