Abstract
Despite recent advances in endoscopic techniques, tumors involving the anterior maxilla remain difficult to reach through a purely endonasal approach. Even with cross-court procedures, lesions involving the anteroinferior and anterolateral corners of the maxillary sinus may be inaccessible endoscopically. Sublabial incisions with canine fossa puncture or a Caldwell-Luc approach are often still necessary for surgical removal of anteriorly based maxillary pathology. The purpose of this chapter is to discuss the endoscopic Denker procedure, a novel technique that involves creation of an endonasal anterior maxillotomy without the need for a separate sublabial incision. With this approach, complete exposure of the anterior maxilla is attained as well as the entire lateral and posterior walls of the maxillary sinus, enabling access to both the pterygopalatine and infratemporal fossae.
Keywords
anterior, Denker, endoscopic, maxilla, maxillotomy, tumor
Introduction
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Despite recent advances in endoscopic techniques, tumors involving the anterior maxilla remain difficult to reach through a purely endonasal approach.
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Even with cross-court procedures, lesions involving the anteroinferior and anterolateral corners of the maxillary sinus may be inaccessible endoscopically.
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Sublabial incisions with canine fossa puncture or a Caldwell-Luc approach are often still necessary for surgical removal of anteriorly based maxillary pathology.
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The endoscopic Denker approach is a technique that involves creation of an endonasal anterior maxillotomy without the need for a separate sublabial incision.
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With this technique, complete exposure of the anterior maxilla is attained as well as the entire lateral and posterior walls of the maxillary sinus, enabling direct access to both the pterygopalatine and infratemporal fossae.
General Principles
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The anteromedial maxillectomy was first described by Alfred Denker in 1906. It involved removal of the ethmoids, lateral nasal wall, and middle and inferior turbinates through a gingivobuccal sulcus incision that was extended medially to the frenulum.
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In 1908, Sturmann and Canfield introduced an endonasal procedure to expose the anterior maxilla.
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An intranasal incision was made posterior to the vestibule.
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Subperiosteal elevation was then performed laterally over the pyriform aperture into the canine fossa to access the anterior wall of the maxillary sinus.
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The endoscopic Denker approach is somewhat of an amalgamation of these two techniques, with the added feature of being performed completely under endoscopic visualization. It has also been referred to as a total endoscopic anterior medial maxillectomy (TEAMM).
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A mucosal incision is initially made along the pyriform aperture followed by elevation of the soft tissues overlying the anterior maxilla in the subperiosteal plane.
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An endoscopic endonasal anterior maxillotomy is then created, taking care to preserve the anterosuperior alveolar and infraorbital nerves.
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The size and position of the maxillotomy may then be adjusted according to the location and extent of the lesion.
Surgical Technique
Step 1: Mucosal Cuts
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Under visualization with a 4-mm 0-degree rod-lens endoscope (Karl Storz Endoscopy, Tuttlingen, Germany), 1% lidocaine HCL with 1:100,000 epinephrine is first injected into the anticipated incision sites along the nasal floor, lateral nasal wall, and anterior to the head of the inferior turbinate ( Fig. 22.1A ).
Fig. 22.1
(A) Anatomy of the left nasal cavity. (B) Intranasal incisions are made with cautery along the dotted lines and carried through the periosteum. Specifically, an inferior incision is made at the junction of the nasal floor and lateral nasal wall, followed by a superior incision along the lateral nasal wall and anteriorly overlying the pyriform aperture. IT, Inferior turbinate; M, middle turbinate; NF, nasal floor; NS, nasal septum.
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A unipolar electrocautery with a guarded needle tip (Megadyne, Draper, Utah) is used to incise the mucosa inferiorly at the junction of the nasal floor and lateral nasal wall, carrying the incision through the periosteum ( Fig. 22.1B ).
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A second mucosal incision is then made superiorly along the lateral nasal wall and carried anteroinferiorly to lie just in front of the anterior head of the inferior turbinate overlying the edge of the pyriform aperture (see Fig. 22.1B ).
Step 2: Soft Tissue Dissection Over the Maxilla
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A subperiosteal dissection is performed with a suction Freer elevator to expose the anterior maxilla, the infraorbital foramen, and its neurovascular bundle as well as the lateral nasal wall ( Figs. 22.2A and B ).
Fig. 22.2
(A) Elevating the mucosa off of the maxilla using a suction Freer. (B) Elevating the mucosa off of the lateral nasal wall. The nasolacrimal duct should be cut sharply once exposed. (C) Drilling is completed to expose the maxillary sinus. AMW, Anterior maxillary sinus wall; IT, inferior turbinate; LNW, lateral nasal wall; NLD, nasolacrimal duct; NS, nasal septum; V2, infraorbital nerve.
Step 3: Bony Cuts to the Maxilla
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A high-speed drill or osteotome is utilized to create a bony window into the anterior maxilla, taking care to stay inferior to the infraorbital nerve (ION) ( Fig. 22.2C ).
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Burs or osteotomes are used to connect the window to the inferior bony cut of the medial maxillectomy, thereby allowing access to the anterior portion of the maxillary sinus.
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In the accompanying video to this book, a recurrent inverted papilloma can be seen pedicled to the anteroinferior corner of the maxillary sinus.
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Once the tumor is dissected free from the surrounding tissue and the site of attachment is identified, the remaining bony and mucosal cuts are completed with burs, osteotomes, and endoscopic scissors, respectively. Specifically, a superior cut is made at the level of the roof of the maxillary sinus, an inferior cut at the junction of the nasal floor and medial maxillary wall, and a posterior cut along the posterior wall of the maxillary sinus. The lesion can then be resected en bloc along with its bony site of attachment, using straight instrumentation ( Fig. 22.3 ).
