Implementation of high-definition fiber tractography for preoperative evaluation and surgical planning of brainstem cavernous malformation: long-term outcomes

Abstract

Objective: The aim of this study was to describe the role and long-term outcomes of high-definition fiber tractography (HDFT) in the surgical management of brainstem cavernomas.

Methods: The authors performed a retrospective evaluation of their database at the HDFT laboratory in a single academic institution.

Results: The authors identified 11 patients with brainstem cavernomas who had HDFT for preoperative workup and underwent microsurgical resection. The mean patient age was 39 years (range 20-76 years), and the mean follow-up was 75.2 months (range 37-149 months). Four cavernomas were located anterolaterally in the pons (2 right and 2 left), 2 were left pontomesencephalic, 1 was thalamomesencephalic, 1 was in the posterior midbrain (right superior colliculus), and 3 were in the posterior pontine/floor of the fourth ventricle. Gross-total resection was achieved in 8 patients (72.7%) and subtotal resection in 3 patients (27.3%). Although 5 patients (45.5%) experienced transient worsening of preoperative symptoms or new deficits, all fully improved within 3 months. None of the patients developed new permanent neurological deficit. Preoperative symptoms improved partially in 8 patients (72.7%) and completely in 3 patients (27.3%). There was one asymptomatic new hemorrhage, and another patient had a symptomatic hemorrhage with a recurrence of his presenting symptoms 15 months after his initial surgery. This patient underwent a re-resection of his residual cavernoma, with no improvement in his preoperative symptoms.

Conclusions: HDFT provides critical anatomical information guiding an optimal surgical corridor and more importantly defining eloquent perilesional boundaries. In this preliminary experience, preoperative planning with HDFT appeared to decrease morbidity in patients who underwent microsurgical resection of their brainstem cavernoma.

Keywords: DTI; brainstem; cavernoma; diffusion tensor imaging; fiber tractography; microsurgery; vascular disorders.