Safety and efficacy of transvenous embolization of cerebrospinal fluid-venous fistula in patients with spontaneous intracranial hypotension

Abstract

Background: Transvenous embolization is a recent treatment strategy for cerebrospinal fluid-venous fistulas (CSFVF), which are associated with spontaneous intracranial hypotension (SIH).

Methods: Participants were selected from a prospective database on patients with CSFVF that received transvenous Onyx embolization. All patients underwent a brain magnetic resonance imaging (MRI) before and after embolization with MRI follow-up performed at least 3 months after treatment. Clinical and MRI results after treatment were described.

Results: Twenty-one consecutive patients (median age 63 years, IQR = 58-71; females: 15/21 = 71.5%) with 30 CSFVF were included. Most lesions were situated between T9 and L1 (19/30 = 63%), 70% were right-sided, and 38% of the patients had multiples fistulas. Embolization was successful in all cases. The mean MRI SIH score before and after treatment was 6 (±2.5) and 1.4 (±1.6), respectively (p < 0.0001). Twenty patients (90%) experienced improvement of their initial condition, of which 67% reported complete clinical recovery. The mean HIT-6 score decreased from 67 (±15) to 38 (±9) (p < 0.0001), the mean amount of monthly headache days from 23.5 (±10) and 3.2 (±6.6) (p < 0.0001), the visual assessment scale (VAS) for headache severity from 8 (±1.9) to 1.2 (±2) (p < 0.0001), and the mean VAS for perception quality of life improved from 2.6 (±2.5) to 8.6 (±1.8) (p < 0.0001). There were no major complications. The suspected rebound headache rate after treatment was 33%.

Conclusion: Transvenous embolization of CSFVF allowed high rates of clinical improvement with no morbidity related to the treatment.

Keywords: CSF loss syndrome; Onyx; Spontaneous intracranial hypotension; cerebrospinal fluid-venous fistula; transvenous embolization.

Figure 1.

A 67-year-old man presenting orthostatic headache, vertigo, bilateral tinnitus, and impaired consciousness. (A) Sagittal and axial T1 MRI after gadolinium showing a severe brain sagging and (B) spontaneous bilateral subdural fluid collection (without history of head trauma), and bilateral symmetric dural enhancement. Lateral decubitus DSM and CT myelography depicted two CSFVF on the right side, (C) one on T5–T6, and the other one (D) on T12–L1. Both fistulas were treated with transvenous Onyx embolization. (E) The Onyx spread was good on the T5–T6 fistula with occlusion of the foraminal veins, intercostal vein, and epidural plexus. We did not achieve a good spread of Onyx at the T12–L1 level: this was our first case, and the injection was ended with the occlusion of the intercostal vein, without contamination of the epidural plexus. The patient considerably improved and the brain sagging disappeared during follow-up. However, the 15-month brain MRI showed persistent bilateral dural enhancement and the patient described the persistence of a moderate orthostatic and effort headache. We decided to repeat a DSM looking for a residual fistula. (F) Right-sided lateral decubitus DSM showing the Onyx cast into the intercostal vein on T12–L1 and the contrast coming after the early phase of myelography. (G) After 30 s, a tiny vein is visible in the T12–L1 level (yellow arrow), demonstrating a residual fistula. (H) Left-sided DSM showed a second CSFVF (yellow arrows) on T11–T12, that was not initially identified. (I) Patient underwent a second transvenous embolization with occlusion of the right epidural plexus on T12–L1 as well as on the left T11–T12. (L) Axial T1 and (M) sagittal T1 MRI after gadolinium showed normalization of the brain MRI. The patient was completely asymptomatic after the second treatment.

Figure 2.

A 39-year-old male with effort related headaches since 3 years. (A) Sagittal T1 MRI after gadolinium showing brain sagging with the effacement of the suprasellar (red arrow), mamillopontine (yellow arrow), and pre-pontine (green arrow) cisterns, as well as cerebellar tonsillar ectopia (blue arrows). Venous sinus engorgement was also present. (B) Left-side lateral decubitus DSM showed a large left T12–L1 CSFVF, that was draining into the left ascending lumbar vein (yellows arrows). (C) Lateral decubitus dual-energy CT scan performed 15 min after the myelography showing a high quantity of renal contrast (yellows arrows). (D) CBCT after transvenous Onyx embolization showing the cast of Onyx occupying the epidural plexus, the foraminal veins, and the ascending lumbar vein at the level of the fistula, and one level above and below. (E) A 24-h sagittal T1 MRI with gadolinium injection showing an increase of the basal cisterns diameter and a tonsillar ectopia reduction, with visualization of a Pacchioni granulation (yellow arrow) inside the torcular, that was not visible before. The patient developed a rebound post-treatment headache probably due to a rebound intracranial hypertension: it is likely that the Pacchioni granulation existed before the leak, yet being hypo-trophic because of the decreased need of CSF absorption due to the SIH. The patient was treated with 1000 mg of Acetazolamide for 2 weeks until the post-treatment headache resolution. (F) Six months sagittal T1 MRI showing the normalization of the basal cisterns diameter. A minimal tonsillar ectopia was still visible at follow-up. The patient was completely asymptomatic at follow-up.