How To: Endoscopic Total Maxillectomy Without Facial Skin Incision

INTRODUCTION

Total maxillectomy is a surgical procedure involving amputation of the orbital floor, zygomatic bone, hard palate, and pterygoid process. It is typically performed in patients with cancer that has invaded the maxillary sinus. A common approach involves an external facial incision through a Weber–Ferguson skin incision; however, this method is associated with post-operative cosmetic complications. Furthermore, the conventional external incision approach is blind to the posterior and nasal sides of the maxillary sinus, which presents challenges in ensuring accurate margins. To compensate for these shortcomings, there are very few reports on endoscopically assisted surgery for advanced cancer of the maxillary sinus; however, there have been no reports of en bloc total maxillectomies in which a single tumor is resected without any facial skin incision. We developed a method for complete removal of the maxilla in cases of maxillary sinus cancer using an endoscopic technique that eliminates the need for facial skin incision. This technique ensures resection of the medial orbital wall and pterygoid process, which would otherwise be obscured by conventional methods.

In this study, three patients who underwent endoscopic maxillary surgery were examined. En bloc resection was successfully achieved in all three cases, with negative margins. The problem with endoscopic surgery is the difficulty in nasal manipulation; however, our co-authors have developed techniques to improve maneuverability. This study presents a pioneering report on an endoscopic total maxillectomy that allows for en bloc resection without a facial skin incision.

METHODS

Patients

Endoscopic total and subtotal maxillary sinus resection procedures were performed in three patients at Jikei University Hospital between April and October 2023. One patient with maxillary sinus cancer and two patients with oral cancer extending into the nasal cavity or maxillary sinus were included. Tumor location, stage, pathology, approach, surgical technique, and resection margins were comprehensively documented. The study was approved by the Ethics Committee (approval number: 34-102) and adhered to the ethical standards of the Human Experimentation Committee of Jikei University School of Medicine and the 1975 Declaration of Helsinki, as revised in 1983. We used an opt-out approach, and none of the patients refused consent.

All Instruments and Settings

We prepared a general nasal sinus endoscopic surgical instrument (Nagashima Medical Instruments, Tokyo, Japan). Endoscopic manipulation was performed using 4 mm rigid 0° and 70° endoscopes (Olympus Medical Systems, Tokyo, Japan). When cutting the mucous membranes of the nose, we used a microneedle electrode with a total length of 14 mm (Muranaka Medical Instruments, Osaka, Japan). When drilling the maxillary bone, a Midas Rex drill system (Medtronic, Minneapolis, USA) with a diamond bur was used to cut the nasal bone and hard palate. When cutting the maxillary bone, we used a high-speed Primado2 bone saw (NSK, Tokyo, Japan). When reconstructing bone, we used the AO Matrix MIDFACE Preformed Orbital Plate (Synthes, Oberdorf, Switzerland). The intra-operative setting was also shown (Fig. 1).

Surgical Technique

A three-dimensional model (LEXI Corporation, Tokyo, Japan) of the facial bone was created prior to surgery. Information on the extent of resection was shared between the head and neck surgery and plastic surgery teams. Considering the tumor location, a surgical passage through the nasal septum was created from the contralateral nasal cavity. An additional surgical passage through the anterior wall of the maxillary sinus was created if the anterior wall was not invaded. For lesions occupying the maxillary sinus, a transconjunctival approach was used with an eyelid conjunctival incision.

The contralateral sinus was opened during endoscopic manipulation. A nasal septal mucosal flap was created and preserved. The anterior wall of the sphenoid sinus was opened through the transnasal septum. The Draf III was performed, and the frontal sinuses were opened on both sides. The nasal septal cartilage was removed to widen the working space inside the nasal cavity on the lesion side. The pyriform aperture was exposed, and the nasolacrimal duct was dissected (Fig. 2A). The periorbita was exposed so as not to touch the tumor protruding into the nasal cavity. To reduce the operative time, endoscopic manipulation and oral incision were performed simultaneously. The anterior wall of the left maxilla was exposed, and the bone was exposed to the maxillary zygomatic ridge. Intraorally, a mucosal incision was made in the hard palate mucosa and around the pterygoid process, and the mandibular muscle process was removed. An eyelid conjunctival incision was made to reveal the orbital rim and expose the anterior wall of the maxillary sinus. The orbital rim and pyriform aperture were identified, and the nasal bone was cut endoscopically (Fig. 2B). The bone of the orbital floor was exposed, and the zygomatic process was cut with a bone saw with endoscopic assistance (Fig. 2C). The bone was exposed after a mucosal incision was made at the base of the nasal cavity. The median part of the hard palate was severed endoscopically, and the borders between the soft and hard palates and the Eustachian tube were also separated (Fig. 2D). The Vidian nerve was identified at the pterygoid base, the sphenopalatine artery was cauterized, and the pterygoid base was shaved from the nasal side (Fig. 2E). Subsequently, the tumor gained mobility, the residual pterygoid muscle was resected, and the mass was removed en bloc. The orbital floor was replaced with a titanium plate, and the maxillary defect was reconstructed with a free fibula. Excess bone protruding into the nasal cavity was shaved and adjusted endoscopically. Finally, the exposed bone was covered with a nasal septal mucocutaneous valve (Fig. 2F).

RESULTS

Regarding endoscopic manipulation, a maximal three-port approach was used in Cases 1 and 2 to perform subtotal maxillectomy (Fig. 3). Case 3 involved a lesion occupying the maxillary sinus (Fig. 4); the zygomatic process was cut via two ports and a transconjunctival approach. A gingival incision was also made in all cases. In all cases, the tumor protruding into the nasal cavity was identified endoscopically and removed as one lump without incision.

Case 1 was histopathologically diagnosed as myoepithelial carcinoma, and Cases 2 and 3 as squamous cell carcinoma, with negative resection margins in all cases, and no additional treatment required. The immediate post-operative and two-month post-operative facial appearances in Case 3 are shown (Fig. 5). The facial appearance and intranasal and oral findings of patients in cases 1 and 2 after surgery are shown (Fig. 6). No facial skin incisions were present, and patients were satisfied with the post-operative cosmetic outcomes. In all cases, the nasal cavity was covered with a mucous membrane, and there was minimal crusting.