Santhosh Kumar Kannath1, Jayadevan Enakshy Rajan2, Sankara P Sarma3. 1. Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, pin no. 695011, Trivandrum, Kerala, India. Electronic address: drsanthoshkannath@gmail.com. 2. Neurointervention Center, Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, pin no. 695011, Trivandrum, Kerala, India. Electronic address: drjayadevan@gmail.com. 3. Achutha Menon Center for Health Science Studies, Sree Chitra Tirunal Institute of Medical Sciences and Technology, pin no. 695011, Trivandrum, Kerala, India. Electronic address: sarma@sctimst.ac.in.
Abstract
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.
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.