Functional Outcomes and Postoperative Cerebral Venous Sinus Thrombosis after Translabyrinthine Approach for Vestibular Schwannoma Resection: A Radiographic Demonstration of Anatomic Predictors

Abstract

Introduction While regarded as an effective surgical approach to vestibular schwannoma (VS) resection, the translabyrinthine (TL) approach is not without complications. It has been postulated that postoperative cerebral venous sinus thrombosis (pCVST) may occur as a result of injury and manipulation during surgery. Our objective was to identify radiologic, surgical, and patient-specific risk factors that may be associated with pCVST. Methods The Institutional Review Board (IRB) approval was obtained and the medical records of adult patients with VS who underwent TL craniectomy at University Hospitals Cleveland Medical Center between 2009 and 2019 were reviewed. Demographic data, radiographic measurements, and tumor characteristics were collected. Outcomes assessed included pCVST and the modified Rankin score (mRS). Results Sixty-one patients ultimately met inclusion criteria for the study. Ten patients demonstrated radiographic evidence of thrombus. Patients who developed pCVST demonstrated shorter internal auditory canal (IAC) to sinus distance (mean: 22.5 vs. 25.0 mm, p = 0.044) and significantly smaller petrous angles (mean: 26.3 vs. 32.7 degrees, p = 0.0045). Patients with good mRS scores (<3) appeared also to have higher mean petrous angles (32.5 vs. 26.8, p = 0.016). Koos' grading and tumor size, in our study, were not associated with thrombosis. Conclusion More acute petrous angle and shorter IAC to sinus distance are objective anatomic variables associated with pCVST in TL surgical approaches.

Translabyrinthine Craniotomy Is Associated with Higher Risk of Asymptomatic Dural Venous Sinus Thrombosis in Vestibular Schwannoma Resection

“…Interestingly, male sex did significantly predict rates of thrombosis in our cohort, with an effect size (OR = 5.53) that persisted on multivariate regression analysis (β = 0.19). This difference is a novel finding, as sex did not predict thrombotic events in other recent studies of CVT in CP angle surgery (8,15). In the general population, young women have the highest reported rates of central venous thrombosis, and men and women do not have significant anatomical differences in sigmoid sinus anatomy (19,20).…”

“…In contrast to RSC approaches, TLC often requires complete skeletonization and compression of the sigmoid sinus early in the case, which may explain the difference in rates of thrombosis between the two approaches (9). Indeed, a shorter distance between the internal auditory canal and sigmoid sinus was identified as an anatomic risk factor for thrombosis during TLC, consistent with physical manipulation as a mechanistic contributor (15). Tumor size and operative time, however, did not significantly affect rates of thrombosis in our series, and previously reported data have had mixed results when taking these risk factors into account (5,8,10).…”

Postoperative Cerebral Venous Sinus Thrombosis Following a Retrosigmoid Craniotomy—A Clinical and Radiological Analysis

“…Patients at an increased risk of CVST (e.g., with the factor V Leiden mutation) should be identified prior to surgery. Outside of medical conditions, Gerges et al, in an anatomic study, found that acute petrous angle and shorter IAC to sinus distance were associated with CVST [15]. CVST prevention is yet to be explored, but clinicians might consider perioperative IV fluids and early anticoagulation postoperatively.…”