Clipping of High-Risk Dural Arteriovenous Fistula of the Posterior Fossa: 3-Dimensional Operative Video

Watch brain circulation in unexplained progressive myelopathy: a review of Cognard type V arterio-venous fistulas

BACKGROUND

Intracranial dural arterio-venous fistulas are pathological anastomoses between arteries and veins located within dural sheets and whose clinical manifestations depend on location and hemodynamic features. They can sometimes display perimedullary venous drainage (Cognard type V fistulas-CVFs) and present as a progressive myelopathy. Our review aims at describing CVFs' variety of clinical presentation, investigating a possible association between diagnostic delay and outcome and assessing whether there is a correlation between clinical and/or radiological signs and clinical outcomes.

METHODS

We conducted a systematic search on Pubmed, looking for articles describing patients with CVFs complicated with myelopathy.

RESULTS

A total of 72 articles for an overall of 100 patients were selected. The mean age was 56.20 ± 14.07, 72% of patients were man, and 58% received an initial misdiagnosis. CVFs showed a progressive onset in 65% of cases, beginning with motor symptoms in 79% of cases. As for the MRI, 81% presented spinal flow voids. The median time from symptoms' onset to diagnosis was 5 months with longer delays for patients experiencing worse outcomes. Finally, 67.1% of patients showed poor outcomes while the remaining 32.9% obtained a partial-to-full recovery.

CONCLUSIONS

We confirmed CVFs' broad clinical spectrum of presentation and found that the outcome is not associated with the severity of the clinical picture at onset, but it has a negative correlation with the length of diagnostic delay. We furthermore underlined the importance of cervico-dorsal perimedullary T1/T2 flow voids as a reliable MRI parameter to orient the diagnosis and distinguish CVFs from most of their mimics.

Tentorial Dural Arteriovenous Fistula Presenting with Venous Congestive Edema of the Upper Cervical Cord

Tentorial dural arteriovenous fistula (DAVF) is an aggressive vascular lesion causing progressive neurological deficits. Venous congestive cervical edema is a rare phenomenon caused by tentorial DAVF. Obliteration of the fistula and venous drainage should be the goal of treatment. A 62-year-old man was admitted with lower limb weakness and numbness. Magnetic resonance imaging (MRI) revealed extensive edema of the upper cervical cord with signal flow void at the anterior spinal cord. Internal carotid angiography revealed a tentorial arteriovenous shunt near the superior petrosal sinus fed mainly by the tentorial artery. The petrosal vein was dilated, with the transverse pontine vein, medial medullary vein, and anterior spinal vein as the main drainage route. This suggests that venous hypertension triggered the upper cervical cord edema. MRI with gadolinium enhancement showed that the varix was located just distal to the shunt. Microsurgical obliteration of the fistula and venous drainage were achieved via a suboccipital approach. A postoperative evaluation showed the disappearance of the cervical cord edema with improved clinical symptoms. Tentorial DAVF with spinal venous drainage presents with mild and slow progression of symptoms. Differential diagnosis and definite treatment are mandatory to avoid a delayed diagnosis and irreversible symptoms.

Intracranial Dural Arteriovenous Fistulas With Brainstem Engorgement: An Under-Recognized Entity in Diagnosis and Treatment

Background: In rare circumstances, patients with intracranial (dural arteriovenous fistulas) DAVFs could be complicated with brainstem engorgement, which might lead to delayed or false diagnosis and subsequent improper management.

Methods: On July 2th, 2019, a systematic search was conducted in the PubMed database for patients with intracranial DAVFs complicated with brainstem engorgement.

Results: Sixty-eight articles reporting of 86 patients were included for final analysis. The patients were aged from 20 to 76 years (57.10 ± 12.90, n = 82). The female to male ratio was 0.68 (35:51). Thirty-three (40.2%, 33/82) patients were initially misdiagnosed as other diseases. The specific location distributions were cranio-cervical junction, cavernous sinus, superior petrosal sinus, transverse and/or sigmoid sinus, tentorium, and other sites in 27 (32.5%), 11 (13.2%), 9 (10.8%), 10 (12.0%), 21 (25.3%), and 5 (6.0%) patients, respectively. The Cognard classification of DAVFs were II, III, IV, and V in 9 (10.7%, 9/84), 1 (1.2%, 1/84), 1 (1.2%, 1/84), and 73 (86.9%, 73/84) patients. Eighteen (22%, 18/82) patients were demonstrated to have stenosis or occlusion of the draining system distal to the fistula points. The mean follow-up period was 7.86 (n = 74, range 0–60 months) months. Fifty-four (70.1%, 54/77) patients experienced a good recovery according to the mRS score.

Conclusions: Intracranial DAVFs complicated with brainstem engorgement are rare entities. Initial misdiagnosis and delayed definite diagnosis are common in the past three decades. The treatment outcome is still unsatisfactory at present. Early awareness of this rare entity and efficiently utilizing the up to date investigations are of utmost importance.