Volumetric Analysis of a Nasopharyngectomy Performed via Endoscopic, Maxillary Transposition and Lateral Temporal-Subtemporal Approaches

Objectives: In an effort to decrease morbidity skull base surgeons have explored less invasive approaches for the resection of nasopharyngeal malignancies. This project presents quantitative data that assesses the practicality, and volumetric exposure afforded during nasopharyngectomy via endonasal and maxillary transposition and lateral preauricular temporal-subtemporal approaches.

Study Design: Subsequently, the study involved the calculation of anatomical volumes using cadaveric and virtual models.

Methods: CT scanning of two anatomical specimens served to recreate computer simulations of the endonasal, maxillary transposition and preauricular approaches, allowing the assessment of their volumes. Two different tumor volumes were constructed, one with limited extent to simulate a T1-T2 lesion and a larger; and, a larger more extensive tumor to simulate a T3-T4 stage.

Results: Pre- and post-dissection CT scans and computer simulations revealed that volumes in the open and endonasal approaches to the nasopharynx are similar, suggesting that volumes of surgical instrumentation, visualization and resection may also be comparable. However, the entry gate for instrumentation differed significantly for each approach.

Conclusion: This study suggests that although the entry gate for instrumentation is greater during an open approach, contrary to intuition, an open approach does not create a substantially larger working space or visual field. Analysis of volumetric measurements facilitates a better understanding of the indications for each procedure.