Post-operative segmental cerebral venous sinus thrombosis: risk factors, clinical implications, and therapeutic considerations

Iatrogenic intracranial venous hypertension treated with intracranial venous stenting: illustrative case

BACKGROUND

Venous sinus injury resulting in thrombosis is a possible complication of skull base surgery and neck dissection. Although usually asymptomatic, sinus thrombosis can obstruct the dominant cranial venous outflow pathways, leading to a cycle of increased intracranial pressure secondary to venous congestion, which further compresses the remaining sinuses in a positive feedback loop. This can present with symptoms resembling idiopathic intracranial hypertension.

OBSERVATIONS

A patient underwent a left mastoidectomy for chronic mastoiditis, complicated by injury of the ipsilateral dominant sigmoid sinus, with subsequent thrombosis. The patient developed chronic severe headaches, papilledema, visual blurring, and tinnitus. Angiography revealed a contralateral arachnoid granulation causing stenosis of the remaining venous outflow tract with a pressure gradient of 18 mm Hg. Transverse sinus stenting led to normalization of the gradient and resolution of symptoms.

LESSONS

Injury of a dominant cranial venous outflow pathway led to a feedback loop that caused increased intracranial pressures and worsening contralateral transverse sinus stenosis, which was successfully treated using transverse sinus stenting. Venous congestive physiology leading to intracranial hypertension is underrecognized as a complication of venous injury in skull base surgery and responds to stenting if the patient's symptoms are refractory to conservative management or anticoagulation. https://thejns.org/doi/10.3171/CASE24781.

Dural Venous Sinus Thrombosis After Vestibular Schwannoma Surgery: Should We Anticoagulate?

BACKGROUND

The incidence of dural venous sinus thrombosis (DVST) following vestibular schwannoma (VS) surgery remains understudied. The diverse clinical presentation complicates forming anticoagulation treatment guidelines. This meta-analysis aimed to investigate the incidence of DVST post-VS surgery and to evaluate the role of anticoagulation.

METHODS

A systematic review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist, was conducted. Studies reporting DVST incidence after VS surgery were included. DVST incidence stratified by detection method was the primary outcome. Adverse events per treatment strategy (anticoagulation or no anticoagulation) were the secondary outcome. Pooled incidence with respective 95% confidence intervals were calculated using the random-effects model via the DerSimonian and Laird method.

RESULTS

The overall DVST incidence post-VS resection was 15.5% (95% confidence interval: 10.3%, 22.5%; 10 studies). Stratification by detection method revealed 29.4% (19.2%, 42.3%) for magnetic resonance imaging, 8.2% (3.2%, 19.5%) for computed tomography, and 0.7% (0.2%, 2.8%) upon clinical suspicion. The pooled incidence of adverse events was 16.1% (6.4%, 35.0%) for the anticoagulation treatment and 4.4% (1.4%, 12.9%) for no anticoagulation treatment, with one mortality case being among the adverse events in this latter group.

CONCLUSIONS

DVST after VS surgery is more common than initially perceived, predominantly presenting asymptomatically. Variability in anticoagulation protocols hinders the establishment of definitive therapeutic stances; nevertheless, there is no supporting evidence to promote anticoagulation administration for DVST. This begs the need for further institutional comparative studies with a proper adjustment for confounding and well-defined anticoagulation regimens.

Prevalence and patterns of cerebral venous sinus thrombosis following vestibular schwannoma surgery: a systematic review and meta-analysis

PURPOSE

Cerebral venous sinus thrombosis (CVST) is a potentially serious complication following surgical treatment of vestibular schwannoma, a benign tumor originating from Schwann cells of the vestibulocochlear nerve. This study aimed to determine the prevalence of CVST following surgical treatment of vestibular schwannoma and the factors contributing to its occurrence.

METHOD

Two independent researchers searched the global databases of PubMed, Web of Science, Scopus, and the Cochrane Library up to September 01, 2023. We employed a random-effects model for data analysis. Heterogeneity was evaluated using the I2 test. To assess the quality of the studies meeting our inclusion criteria, we employed the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

We included 23 articles in this meta-analysis. The pooled prevalence of CVST after vestibular schwannoma surgery was 6.4% (95%CI 3.4-11.5%). The pooled prevalence of CVST following the retrosigmoid (RS), translabyrinthine (TL), and middle cranial fossa (MCF) approaches was 4.8% (95%CI 2.0-11.0%), 9.6% (95%CI 4.3-20.3%) and 9.9% (95%CI 1.6-42.2%), respectively, revealing a significant difference between the TL and the RS approaches (Odds ratio = 2.10, 95%CI 1.45-3.04, P < 0.001). The sigmoid sinus exhibited the highest post-operative thrombosis rate (7.9%), surpassing the transverse sinus (3.7%) and involvement of both sigmoid and transverse sinuses (1.6%), respectively. No significant associations were found with demographic or surgical factors.

CONCLUSION

In the current meta-analysis, we identified a 6.4% CVST prevalence following vestibular schwannoma surgery, with varying rates depending on the surgical approach. No significant associations with patient or surgical factors were found, emphasizing the need for heightened clinical vigilance and further research in this context.

TRAIL REGISTRATION

PROSPERO ID: CRD42023453513.

The effect of SARS-CoV-2 on the incidence of post-operative venous sinus thrombosis following skull base procedures

PURPOSE

Sinus thrombosis is a common post-operative finding after posterior fossa surgery performed in the vicinity of the dural venous sinuses. The SARS-CoV-2 virus has been shown to confer an increased risk of venous thromboembolic events owing to eliciting a hyper-inflammatory and pro-thrombotic state. In this study, we examine the incidence of post-operative venous sinus thrombosis in patients undergoing peri-sigmoid posterior fossa surgery in the pre- and post-COVID era and investigate whether COVID infection confers an increased risk of sinus thrombosis.

METHODS

A retrospective review of a single institution case series of patients underwent peri-sigmoid surgery (retrosigmoid, translabyrinthine, or far lateral) approach. Relevant clinical variables were investigated that may confer an increased risk of sinus thrombosis.

RESULTS

A total of 311 patients (178 in the pre-COVID era, and 133 operated on after the pandemic began in March 2020) are included in the study. The composite incidence of sinus thrombosis seen on post-operative imaging was 7.8%. The incidence of sinus thrombosis in the pre-COVID cohort was N = 12 patients (6.7%) versus N = 12 (9%) in the post-COVID cohort (p = 0.46). A history of COVID infection was not shown to confer an increased risk of post-operative sinus thrombosis (OR: 0.61; 95% CI: 0.08-4.79, p = 0.64). Only a small number of patients (N = 7, 2.3%) required either medical or surgical intervention for post-operative sinus thrombosis.

CONCLUSION

The overall incidence of post-operative sinus thrombosis is similar in the pre- and post-COVID era. The findings of this study suggest that COVID infection is not associated with a higher risk of venous sinus thrombosis.

Venous Sinus Thrombosis-Associated with Posterior Cranial Fossa Surgery. A Systematic Review and Meta-Analysis of Natural History, Risk Factors, Treatment, and Outcome

BACKGROUND

Venous sinus thromboses (VSTs) are rare complications of neurosurgical procedures in the proximity of the dural sinuses. Surgery of the posterior cranial fossa (PCF) and particularly of the cerebellopontine angle (CPA) shows increased risk of VST. VST management is challenging because anticoagulant therapy must be balanced with the risk of postoperative bleeding. We performed a systematic review and meta-analysis to summarize the most important neuroradiologic and clinical aspects of VST after PCF/CPA surgery.

METHODS

We performed a comprehensive literature search to identify articles reporting data on VST after PCF/CPA surgery. We selected only comparative studies providing adequate neuroimaging assessing VST and a control group.

RESULTS

We included 13 articles reporting 1855 patients. VST occurred in 251/1855 cases (estimated incidence, 17.3%; 95% confidence interval [CI], 12.4%-22.2%). Only presigmoid approach (odds ratio [OR], 2.505; 95% CI, 1.161-5.404; P = 0.019) and intraoperative sinus injury (OR, 8.95; 95% CI, 3.43-23.34; P < 0.001) showed a significant association with VST. VST-related symptoms were reported in 12/251 patients with VST (pooled incidence, 3.1%; 95% CI, 1%-5.2%). In particular, we found a significantly increased OR of cerebrospinal fluid leak (OR, 3.197; 95% CI, 1.899-5.382; P < 0.001) and cerebrospinal fluid dynamic alterations in general (OR, 3.625; 95% CI, 2.370-5.543; P < 0.001). Indications for VST treatment were heterogeneous: 58/251 patients underwent antithrombotics, with 6 treatment-related bleedings. Recanalization overall occurred in 56.4% (95% CI, 40.6%-72.2%), with no significant difference between treated and untreated patients. However, untreated patients had a favorable outcome.

CONCLUSIONS

VST is a relatively frequent complication after PCF/CPA surgery and a presigmoid approach and intraoperative sinus injury represent the most significant risk factors. However, the clinical course is generally benign, with no advantage of antithrombotic therapy.

Presentation and Management of Cerebral Venous Sinus Thrombosis After Supratentorial Craniotomy

BACKGROUND AND OBJECTIVES

Cerebral venous sinus thrombosis (CVST) after supratentorial craniotomy is a poorly studied complication, for which there are no management guidelines. This study assessed the incidence, associated risk factors, and management of postoperative CVST after awake craniotomy.

METHODS

This is an observational, retrospective, monocentric analysis of patients who underwent a supratentorial awake craniotomy. Postoperative CVST was defined as a flow defect on the postoperative contrast-enhanced 3D T1-weighted sequence and/or as a T2* hypointensity within the sinus.

RESULTS

In 401 supratentorial awake craniotomies (87.3% of diffuse glioma), the incidence of postoperative CVST was 4.0% (95% CI 2.5-6.4): 14/16 thromboses located in the superior sagittal sinus and 12/16 located in the transverse sinus. A venous sinus was exposed during craniotomy in 45.4% of cases, and no intraoperative injury to a cerebral venous sinus was reported. All thromboses were asymptomatic, and only two cases were diagnosed at the time of the first postoperative imaging (0.5%). Postoperative complications, early postoperative Karnofsky Performance Status score, and duration of hospital stay did not significantly differ between patients with and without postoperative CVST. Adjusted independent risk factors of postoperative CVST were female sex (adjusted Odds Ratio 4.00, 95% CI 1.24-12.91, P = .021) and a lesion ≤1 cm to a venous sinus (adjusted Odds Ratio 10.58, 95% CI 2.93-38.20, P < .001). All patients received standard prophylactic-dose anticoagulant therapy, and none received treatment-dose anticoagulant therapy. No thrombosis-related adverse event was reported. All thromboses presented spontaneous sinus recanalization radiologically at a mean of 89 ± 41 days (range, 7-171).

CONCLUSION

CVST after supratentorial awake craniotomy is a rare event with satisfactory clinical outcomes and spontaneous sinus recanalization under conservative management without treatment-dose anticoagulant therapy. These findings are comforting to neurosurgeons confronted with postoperative MRI reports suggesting CVST.