Research Paper published in Radiology (Latest)


Internal carotid artery aneurysms are rare pathologies. Endovascular treatment of these disorders is new and emerging field of interventional neurology. A 50 year old male presented to our unit with progressive headaches, visual disturbance and panhypopituitarism. Investigations revealed a giant fusiform right cavernous internal artery aneurysm (39 x 33 x 37 mm). He underwent endovascular treatment with a Surpass flow diverting stent and subsequently developed a cavernous sinus syndrome and carotid-venous fistula. A novel stent-in-stent technique was utilized and a Surpass Streamline 3 x 25 mm flow-diverting stent was placed across the fistulating zone of the initial stent, with clinical resolution of symptoms.

Flow diverting stents are a new class of neuro-interventional devices for the management of intracranial aneurysms not amenable to conventional techniques [1]. Complications include thromboembolism, intracranial haemorrhage, vessel injury and delayed rupture [2]. Carotid-venous and Carotico-cavernous fistulae (CCF) may result when the aneurysm involves the intracavernous portion of the internal carotid artery (ICA), with rupture resulting in direct communication with the cavernous sinus. Development of such fistulae after flow-diverting stents has only sparsely been reported. This article is the first case report of a carotid-venous fistula in the acute period following treatment with the Surpass flow diverting stent (Stryker, Neurovascular, Fremont, California, USA). It reports a novel ‘stent-in-stent’ technique using a second flow diverting stent to reduce flow through fistula with clinical symptom resolution.

A 50 year old otherwise healthy male presented with a four month history of severe headaches associated with nausea and progressive visual disturbance. He also reported a chronic history of erectile dysfunction and profound lethargy. Laboratory results were significant for panhypopituitarism.

He underwent endovascular treatment with the use of a flowdiverting stent. He was premedicated with aspirin and clopidogrel. Through the right femoral artery, a Navien 058 access catheter and an XT-27 Micro-catheter were used to successfully access the outflow vessel, deploying a 4 × 40 mm Surpass flow-diverting stent across the aneurysm (Figure 5). The inferior, petrous portion required post dilatation with a 4 × 15 mm balloon with significant improvement in status.

Three days post-procedure he developed a cavernous sinus syndrome. Repeat CTA delineated de novo venous pathways through the petrous temporal bone and occipital diploe caused by the aneurysm, with subsequent cavernous sinus region remodeling. Hence it reflected the development of a carotid-venous fistula rather than a conventional carotid cavernous fistula (CCF).

The decision was made for initial conservative treatment to facilitate positive remodeling with stent endothelialisation and aneurysm thrombosis. One month post-procedure, due to ongoing symptoms, trans- venous embolization was attempted. The right common femoral vein was used to access the right internal jugular vein at the level of the skull base. This attempt was aborted due to difficulty negotiating the fistulated venous plexus.

Despite progressive aneurysm thrombosis and reduction in flow through the fistula, the patient continued to experience disabling pulsatile tinnitus. After multidisciplinary discussion, and given the previously attempted embolization a decision was made to attempt arterial correction of the carotid-venous fistula. The right common femoral artery was accessed and a Navien 035 was used to traverse the existing stent. A Surpass Streamline 3 × 25 mm flowdiverting stent was placed across the fistulating zone of the initial stent (Figure 6). An 8Fr Neuron Max sheath was positioned at the right ICA, and a Navien 035 was used to traverse the existing stent.

Ann Jose
Associate Editor
Journal of Imaging & Interventioal Radiology