Natural History of Untreated Transverse/Sigmoid Sinus Thrombosis Following Posterior Fossa Surgery: Case Series and Literature Review.

Background: Transverse or sigmoid sinus thrombosis occurs in 4% to 11% of patients following posterior fossa surgery. Anticoagulation has been the mainstay treatment, mostly based on extrapolation from the literature on spontaneous sinus thrombosis.

Objective: To analyze the rate and associated complications of postoperative transverse/sigmoid sinus thrombosis for patients undergoing posterior fossa tumor resection. In this series, no antithrombotic therapy was initiated, and no postoperative treatment alterations were made following thrombosis diagnosis.

Methods: Prospectively accrued cases from a single surgeon operating at a single academic center were retrospectively reviewed to determine the natural history of untreated transverse/sigmoid sinus thrombosis following posterior fossa surgery. Inclusion criteria were patients 18 yr or older undergoing resection of a posterior fossa tumor. A total of 538 patients were analyzed.

Results: In all 26 out of 538 (4.8%) patients were diagnosed with transverse/sigmoid sinus thrombosis on routine postoperative imaging. Early postoperative complication rate was 38% in the sinus thrombosis group, as compared to 15% in the no-thrombosis group (P = .02). A significantly higher rate of pseudomeningocele, dysphagia requiring gastrostomy, and cerebellar stroke signs were noted in patients with postoperative sinus thrombosis. However, only 3 of the 26 patients (12%) with postoperative sinus occlusion suffered prolonged central nervous system complications.

Conclusion: Transverse/sigmoid sinus thrombosis following suboccipital craniectomy results in a higher rate of early complications; however, most of these complications resolve without anticoagulation. It may be reasonable, therefore, to manage these patients conservatively in order to avoid the risks associated with anticoagulation in the perioperative period.