Efficacy of the Endoscopic Triportal Transmaxillary Approach for Treating Lateral Middle Skull Base Tumors: A Technical Note and Retrospective Case Series

Abstract

The endoscopic approach, chiefly via the maxillary sinus, has growing applications for the lateral skull base, and can be classified into the use of "endonasal" or "sublabial" entry. Although the endonasal transmaxillary approach has been well accepted, it has a limitation with respect to the lateral exposure. A possible solution is the use of the sublabial transmaxillary approach via the canine fossa, which assures lateral accessibility. In clinical practice, we have taken advantage of the concomitant use of the endonasal and sublabial transmaxillary approach for selected patients harboring lateral skull base lesions. In addition to binostril pathways, canine fossa trephination was constructed to facilitate this combined approach, termed the endoscopic triportal transmaxillary approach (ETTA). The efficacy of the ETTA was evaluated within a case series. A single-institution retrospective analysis was performed in patients with lateral middle skull base tumors treated via ETTA. In clinical practice, 4 patients were eligible for the study, including 1 receiving a combined endoscopic and transcranial approach. No major complications occurred in patients included in this series. The ETTA facilitated the dynamic manipulation of instruments, which led to rapid hemostasis and the satisfactory surgical resection of tumors. Furthermore, it reduced intraoperative postural stress experienced by the surgeons who performed the procedures. The concomitant use of the trans-canine fossa approach effectively ameliorated significant technical challenges that tend to occur when using a purely endonasal approach. The ETTA can be an attractive option for treating lateral and middle skull base lesions.