Volumetric comparative analysis of anatomy through far-lateral approach: surgical space and exposed tissues

Background The three-dimensional (3D) visualization model has ability to quantify the surgical anatomy of far-lateral approach. This study was designed to disclose the relationship between surgical space and exposed tissues in the far-lateral approach by the volumetric analysis of 3D model. Methods The 3D skull base models were constructed using MRI and CT data of 15 patients (30 sides) with trigeminal neuralgia. Surgical corridors of the far-lateral approach were simulated by triangular pyramids to represent two surgical spaces exposing bony and neurovascular tissues. Volumetric comparison of surgical anatomy was performed using pair t test. Results The morphometric results were almost the same in the two surgical spaces except the vagus nerve (CN X) exposed only in one corridor, whereas the volumetric comparison represented the statistical significant differences of surgical space and bony and neurovascular tissues involved in the two corridors (P<0.001). The differences of bony and neurovascular tissues failed to equal the difference of surgical space. Conclusions For far-lateral approach, the increase of exposure for the bony and neurovascular tissues is not necessarily matched with the increase of surgical space. The volumetric comparative analysis is helpful to provide more detailed anatomical information in the surgical design.

Minimally Invasive Surgical Technique for the Management of Giant Dumbbell Spinal Schwannoma

Background Completely extradural spinal schwannomas have a unique morphology (dumbbell tumors) with an intra- and extraspinal component. When they compromise two contiguous vertebral bodies or have an extraspinal extension >2.5 cm, they are classified as giant spinal schwannomas. The aim of this study is to present our experience in the surgical management of completely extradural giant spinal schwannomas with a minimally invasive approach. Methods This study is a case series of patients treated at the Neurosurgery Department of the University Clinical and Provincial Hospital of Barcelona, Spain, between January 2016 and December 2019. Results Fifteen patients met the inclusion criteria, with thoracic and lumbar spines being the most frequent locations. All patients underwent surgical treatment, with a mini-open interlaminar and far-lateral technique. Total gross resection was accomplished in all patients and spine instrumentation was not necessary. Conclusions Microsurgery is the treatment of choice for spinal schwannomas, and gross total resection with low morbidity must be the surgical goal. Mini-open interlaminar and far-lateral access is a valid surgical option, with low morbidity in experienced hands, and there is no need for spinal instrumentation.