A case series to assess transvenous paraspinal vein embolisation of cerebrospinal fluid (CSF)-venous fistulas—a novel treatment approach for spontaneous intracranial hypotension (SIH)—has resulted in a “clinical and radiographic improvement” across all the patients involved. The findings of this case series are published in the American Journal of Neuroradiology (AJNR).
In addition to stating that no technical or permanent neurologic complications were seen in any of the five patients, the report’s authors, interventional neuroradiologist Waleed Brinjikji (Mayo Clinic, Rochester, USA) et al, conclude that “our findings are important because they suggest that CSF-venous fistulas may be amenable to obliteration via transvenous embolisation and may not require surgical intervention”.
According to the authors, a number of treatment options have previously been proposed for CSF-venous fistulas—which are increasingly being recognised as a cause of SIH—including “extremely effective” surgical ligation, nerve root skeletonisation, and blood/fibrin patching. Despite this, they also note that a recent series involving 42 patients saw an 80% improvement or resolution in magnetic resonance (MR) imaging findings of CSF hypotension, while other minimally invasive treatment options like epidural blood patches and fibrin glue injections “have been shown to be effective in a minority of patients”.
They therefore set out to report the “first ever” cases of transvenous paraspinal vein embolisation being used to treat CSF-venous fistulas, which involved retrospectively reviewing five patients diagnosed with a CSF-venous fistula on digital subtraction myelography (DSM). For the novel endovascular procedure, they opted to occlude the venous outflow of the CSF-venous fistula using a liquid embolic material (Onyx, Covidien).
The transfemoral route was used to gain access for the procedure in four patients, while a transjugular approach was used in one. Four of these patients were male and one was female, and their mean age was 60 years. Brinjikji et al report that all patients had position- and Valsalva-dependent headaches, two had hearing loss, four had tinnitus, and three had cognitive disturbances described as “brain fog”.
Regarding the results of the case series, the authors write: “At last follow-up [median=three months; range=two to four months), all patients had documented clinical improvement. Three patients had complete resolution of SIH-related symptoms. One patient had complete resolution of headaches and hearing loss but had persistent tinnitus. However, this patient was found to have a semicircular canal dehiscence, which confounded the evaluation of the tinnitus. One patient, [who had] mild residual pachymeningeal enhancement, had a 50% improvement in headache and hearing loss, but persistent tinnitus.
“In all cases, the fistulas were localised using DSM and, in all cases, embolisation resulted in significant improvement in both imaging findings and clinical symptoms. Pain localised to the site of the embolisation was a common minor complication, but in no cases did this require narcotics, and in all cases the pain subsided in a matter of weeks. All procedures were performed on an outpatient basis and there were no permanent neurologic deficits.”
Brinjikji et al also note that all five patients were discharged home on the day of the procedure. Despite the reported positive findings associated with transvenous paraspinal vein embolisation for CSF-venous fistulas, the authors add that limitations of their case series include the relatively short follow-up duration of two to four months, a lack of uniform pre-treatment MR imaging protocols due to the patients being referred from multiple different centres, and the fact that measures—such as the Headache Impact Test-6, quality of life, and other standardised questionnaires—were not collected. As such, they conclude that “further studies are needed to confirm our technique and to study the durability of this treatment effect”.