Anatomic research of minimally invasive surgical route for presigmoidal approach exposing jugular tubercle by virtual reality skill

Abstract

Objective To discuss how to scale down the range of surgical route for the presigmoidal approach exposing jugular tubercle based on virtual reality image model. Methods CT and MRI images of fifteen adult cadaver heads were used to establish virtual reality anatomic model of petrous bone and posterior cranial fossa. The mastoidal tip was selected as landmark point of craniotomy through presigmoidal approaches. The anterior edge of jugular tubercle was selected as exposure landmark points on the skull base. The lines between craniotomy and exposure landmark points were used as axis to outline cylinders with diameter of 2 cm simulating surgical routes of and presigmoidal approach. Minimally invasive design was made by reducing the diameter of cylinder to 1 cm. Anatomic exposure before and after minimally invasive design were observed and measured. Statistical comparison was launched by paired t test. Results Surgical route before minimally invasive design passed through the anterior edge of sigmoid sinus, the bottom of jugular bulb, internal jugular vein and inferior petrosal sinus. The route also passed through glossopharyngeal nerve, vagus nerve, accessory nerve and hypoglossal never, and then, involved partial internal carotid artery [(41.57±2.38) mm3] and anterior inferior cerebellar artery [(60.64±2.13) mm3]. The surgical route following minimally invasive design passed through partial jugular bulb, internal jugular vein, inferior petrosal sinus and accessory nerve. The volumes of surgical route before minimally invasive design, osseous structures, cranial nerve and vein involved [(2 168.00±12.90)mm3 vs (7 083.40±156.24)mm3, (26.43±1.71)mm3 vs (130.24±1.88)mm3, (780.32±18.74)mm3 vs (2 411.00±162.86)mm3] were less than those of surgical route following minimally invasive design with statistical significance (t=114.349, 217.286, 54.402, all P values<0.01). Conclusions Simulative surgical route can determine operative direction and range. Compared with route before minimally invasive design, minimally invasive route of presigmoidal approach exposing jugular tubercle can reduce intraoperative bone drilling and injure of neurovascular structures. Key words: Presigmoidal approach; Virtual reality; Three-dimensional anatomy; Jugular tubercle; Skull base