Spinal CSF leaks in spontaneous intracranial hypotension: A single-institution analysis of incidence, typology and treatment outcomes

Abstract

Objective: To report incidence, typology and treatment outcomes of spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH).

Methods: In this IRB approved study, consecutive SIH patients with myelogram-confirmed spinal CSF leak location, who underwent treatment between 2021 and 2023 at a single institution were retrospectively analyzed. The outcome variable was definitive treatment of SIH, defined as clinical and/or radiographic resolution of symptoms. Leak type classification was: Type 1 = ventral dural tear, Type 2 = lateral dural nerve root sleeve tear, Type 3 = CSF-venous fistula (CVF).

Results: 32 SIH patients (average age 48 ± 15, 28 % male, 72 % female) were analyzed. A majority of them had a Type 1 CSF leak (59 %), followed by Type 3 (31 %) and Type 2 (9 %) leaks. Thoracic spine was the predominant location of the leaks (84 %); notably all CSF-venous fistulas were located there. Following trials of conservative management, all patients underwent treatment with EBP after leak site localization. 22/32 patients (69 %) had at least some resolution of symptoms following the first EBP. For 2/32 (6 %, both Type 2 leak), one targeted EBP provided definitive treatment. 30/32 (94 %, all leak types) had persistent clinical symptoms and had additional EBP(s). The mean number of EBPs per patient was 1.4 (range = 1-3). Following treatment failure of EBP(s), 10 patients with Type 3 leaks had transvenous embolization, which resulted in definitive treatment for 9 (90 %); 16 patients (leak Type 1 = 15, Type 2 = 1) had open dural surgery, which resulted in definitive treatment for 15 (94 %, all Type 1 leaks).

Conclusion: Overall, our analysis is consistent with recent data demonstrating that SIH incidence is higher among female patients and that CVFs are slightly more prevalent than previously reported, seen in nearly a third of our patients. Thoracic spine is the predominant location of CSF leaks; all our CVFs were located there. On treatment modalities, while EBP remains an important tool offering immediate symptom relief to SIH patients in the short term, permanent closure of the CSF leak and complete resolution of symptoms is rarely achieved with EBP. Definitive treatment is more likely with targeted endovascular and surgical modalities.

Keywords: CSF Leak; CSF-venous Fistula; Epidural Blood Patch; Open Dural Surgery; Spontaneous Intracranial Hypotension; Transvenous Embolization.