Anatomical localization of the cavernous sinus dural fistula by 3D rotational angiography with emphasis on clinical and therapeutic implications.

BACKGROUND AND PURPOSE: Carotid cavernous sinus dural arteriovenous fistulas (CSDAVFs) are presumed to be located within the walls of the cavernous sinus, however the exact fistulous site has not yet been studied by angiographic or anatomical methods. The present study aimed to localize CSDAVFs with the help of 3D rotational angiography (RA) and correlated the observations with clinical and angiographic findings. MATERIALS AND METHODS: The CSDAVFs were categorized as dural, extradural or osseous based on the site of convergence of feeders into the venous sac. Extradural CSDAVFs were further subcategorized into posteromedial, posterolateral and anterior subtypes, depending on proximity to a possible venous plexus. This classification was correlated with various clinical presentations and angiographic subtypes. RESULTS: Thirty-seven patients were included in the final analysis. The sac was identified in all the patients and the mean sac size of the fistula was small (<4mm). Dural type was associated with exclusive cortical venous drainage. Extradural anterior CSDAVF showed tendency towards younger age predilection. Extradural posterolateral CSDAVF was more often associated with initial oculomotor nerve palsy and this observation was statistically significant. Discordancy between the location of the fistula and the side of clinical affection was observed in midline fistulas such as osseous CSDAVF and posteromedial type of extradural CSDAVF. CONCLUSIONS: CSDAVF is a heterogeneous vascular disorder involving the sphenoclival bone, extradural space and dura, homologous to the epidural-dural shunts of vertebra with a common clinical presentation of orbital manifestations. Preoperative localization of the fistula could explain enigmatic observations and potentially simplify its interventional management.

Preoperative Angiographic Protocol for the Surgical Management of Spinal Dural Arteriovenous Fistulas: A Technical Nuance for Safe Minimally Invasive Surgery.

BACKGROUND: Interruption of the fistulous point is the goal of treatment of spinal dural arteriovenous fistulas (dAVFs). Microsurgery remains a highly efficient treatment in terms of complete occlusion with the lowest risk of recurrence rate. It is reported that the hardest step involves finding the fistulous site itself, potentially extending surgical access and time and increasing potential postoperative surgical-related complications. The accurate preoperative detection of the shunt and spinal level together is crucial for guiding optimal, fast, and safe microsurgical treatment. METHODS: We describe a preoperative angiographic protocol for achieving a safe and simple resection of spinal dural arteriovenous fistulas based on a 6-year institutional experience of 42 patients who underwent minimally invasive procedures. Two illustrative cases are included to support the technical descriptions. RESULTS: The suspected artery associated with the vascular malformation of interest is studied in our angiographic protocol through nonsubtracted selective acquisitions in lateral projection. The resulting frames are reconstructed with three-dimensional rotational angiography. The implementation of the preoperative angiographic protocol allowed 100% of intraoperative identification of the fistulous point in all cases with the use of a minimally invasive approach. CONCLUSIONS: Nowadays, neurosurgeons advocate for minimally invasive procedures and procedures with low morbidity risk for treatment of spinal dural arteriovenous fistulas. Our preoperative approach for accurate angiographic localization of the fistulous point through nonsubtracted and three-dimensional reconstructed angiography allowed us to achieve safe and definitive occlusion of the shunt.

Focus on the target: Angiographic features of the fistulous point and prognosis of transvenous embolization of cavernous sinus dural arteriovenous fistula.

Background and purpose Transvenous embolization (TVE) is widely utilized as an effective and safe treatment option for cavernous sinus dural arteriovenous fistula (CS-dAVF); however, detecting the exact location of the fistula is challenging. The present study identified the angiographic features of the fistulous point and evaluated the match with the microcatheter tip and fistulous point. Materials and methods An analysis cohort of 45 consecutive patients with CS-dAVF treated by TVE was analyzed retrospectively. The patients were divided into two groups, 22 matches and 23 mismatches, according to whether the fistulous point and the microcatheter tip were in the same compartment of the cavernous sinus (CS). The angiographic findings, the location of the fistulas, the position of the microcatheter tips, the volume of embolic materials, complications, and outcomes were assessed. Results Several angiographic features defined the fistulous points, such as the early opacified area, jellyfish-like sign, changes in the density of the contrast medium, the juncture of different arterial supply, enlarged feeders, and hand-injection angiograms. The fistulas were primarily in the posterosuperior portion of the CS (80%) and medial side (73.3%) according to the internal carotid artery. Both groups achieved effective TVE; the matched group required less embolic material than the mismatched group ( p = 0.024). The patients with cranial nerve dysfunction (CND) required more embolic materials than others ( p = 0.032). Conclusion The fistulous point in most of the CS-dAVFs could be isolated by careful analysis of the angiography images. The matching of the microcatheter tip and fistulous point in the same compartment of CS can reduce the dosage of embolic materials, and a low volume of embolic materials might cause fewer CND complications.

A novel technique for identifying the fistulous point in a direct carotid-cavernous fistula.

The fistulous point in a direct carotid-cavernous fistula (CCF) can often be difficult to identify because of high-flow shunting. A novel technique that is useful for identifying the fistulous point is reported. A 71-year-old woman underwent endovascular therapy for a left direct CCF that presented with sudden diplopia and tinnitus. To identify the fistulous point, vertebral angiography with manual compression of the left carotid artery was attempted, as was slow injection of a contrast agent from a balloon guiding catheter, closing off the left internal carotid artery; however, the shunt flow was very rapid, and identification was not possible. Therefore, three-dimensional digital subtraction angiography of the vertebral artery was performed while also performing manual aspiration from the balloon guiding catheter, closing off the left internal carotid artery. This reduced early visualization of the cavernous sinus and enabled an aneurysm in the cavernous sinus to be clearly visualized. Embolization was performed transarterially and transvenously, and the shunt flow disappeared completely. Vertebral angiography combined with manual aspiration from a balloon guiding catheter closing off the internal carotid artery is useful for identifying the fistulous point in a direct CCF.