Giant cavernous carotid aneurysm with spontaneous ipsilateral ICA occlusion: Report of 2 cases and review of literature

Spontaneous thrombosis and calcification of giant cavernous carotid artery aneurysm: A rare case and management insights

Background

Giant cavernous carotid artery aneurysms (>25 mm) are rare (3-5%), with some prone to spontaneous thrombosis (10-20% complete). We present a unique case of one of the largest aneurysms spontaneously thrombosing and calcifying.

Case Description

A 57-year-old with persistent right-sided headaches had a substantial hyperdense mass in the right middle cranial fossa, eroding petrous bone. Magnetic resonance imaging and digital subtraction angiography revealed a giant cavernous segment fusiform aneurysm of the right internal carotid artery (ICA) with spontaneous thrombosis and distal ICA occlusion. Collateral circulation maintains the cerebral blood supply. Despite anatomical challenges, conservative management was chosen due to the patient's stability.

Conclusion

This case highlights the complex interplay between thrombosed giant aneurysms and affected vessels, with unique features such as cross-flow, calcification, and bone erosion. We advocate conservative management for stable cases, supported by literature, emphasizing vigilant follow-up. This expands the spectrum of aneurysm presentations and encourages further research into their dynamics.

Spontaneous thrombosis of a giant cavernous-carotid aneurysm with simultaneous ipsilateral complete parent artery occlusion: a rare phenomenon and review of the literature

Cavernous-carotid artery (CCA) aneurysms represent about 3-5% of all intracranial aneurysms. Spontaneous thrombosis of a CCA aneurysm with simultaneous occlusion of its parent vessel is an extremely rare phenomenon with few reported cases in the literature offering different management strategies. A 54-year-old Asian female presented with a one day-history of painless left eye conjunctival injection, proptosis, and features of cavernous sinus syndrome (cranial nerve III, IV, V1, V2, and VI palsies). Imaging revealed a giant thrombosed CCA aneurysm measuring 3.6cmx3.4cm with complete thrombosis of the left cervical internal carotid artery (ICA) and adequate collaterals from the anterior and posterior communicating artery and branches of the left external carotid artery. Management was conservative with antiplatelet therapy and close clinical-radiological follow-ups. The outcome was satisfactory. Data in the literature on this condition is limited due to its exceedingly rare occurrence. The majority of patients do well via a conservative approach and surgery is rarely indicated. For clinically stable patients, especially those with adequate collateral circulation and tolerance to Balloon Test Occlusion, we advocate for a conservative approach and initiation of anti-platelet therapy to treat these patients. Emphasis is needed on close serial clinical-radiological surveillance in these cases to monitor the propagation of the thrombus as well as the development of new and/or enlarging pre-existing aneurysms in the contralateral ICA circulation.

A pediatric case of completely thrombosed giant cavernous carotid aneurysm with ipsilateral ICA occlusion mimicking an intra-axial cystic lesion: a case report and review of the literature

INTRODUCTION

There have been a few cases where completely thrombosed cavernous carotid artery (CCA) aneurysms have resembled neoplasms based on neuroimaging data, but no reports have been documented in children.

CASE REPORT

We describe an unusual pediatric case of a huge cavernous sinus mass mimicking a cystic neoplasm with peripheral rim enhancement on magnetic resonance imaging (MRI), where the surgery and subsequent histopathological investigation revealed that this mass was a completely thrombosed giant aneurysm of the CCA. The patient showed postoperatively no new neurological deficits and discharged a week later after surgery.

CONCLUSIONS

In this case report, we describe a pediatric case of a completely thrombosed giant CCA aneurysm with ipsilateral internal carotid artery (ICA) occlusion, which imitates an intra-axial cystic lesion on MRI.

Loss of Contralateral Upper Limb Motor Evoked Potential Due to Occlusion of the Internal Carotid Artery in Microsurgical Clipping of Basilar Tip Aneurysm

The motor evoked potential (MEP) monitoring is routinely used as an adjunct in the microsurgical clipping of anterior circulation. We describe a case of unruptured basilar tip aneurysm treated with microsurgical clipping developed loss in MEP recording of the left abductor pollicis brevis (APB) following clipping of basilar tip aneurysm. A 58-year-old man was referred to the Fujita Health University Banbuntane-Hotokukai Hospital, Nagoya, Aichi, Japan, with incidental finding of unruptured 6.5 mm basilar tip saccular aneurysm. He underwent right anterior temporal approach of basilar tip aneurysm clipping. The internal carotid artery (ICA) was mobilized laterally to allow direct visualization of the neck of the basilar tip aneurysm. Following the application of temporary clip and subsequently permanent clip at the neck of the aneurysm, the MEP signal was lost in the left APB. The temporary clip was immediately removed. Dual-image videoangiography (DIVA) showed a filling defect in the right ICA and a branch of middle cerebral artery (MCA). The MEP was absent for about 23 minutes and the amplitude improved to only 75% of the baseline recording at 38 minutes till the end of the surgery. A repeat DIVA showed good flow within the right ICA and MCA. Glasgow coma score was 15/15 on postoperative day 1 and there was no gross motor or sensory deficit except right oculomotor nerve palsy with complete recovery at 6 months follow-up. This is the first reported ICA occlusion due to its mobilization in microsurgical clipping of basilar tip aneurysm. The use of neuromonitoring especially MEP is essential even in the posterior circulation aneurysm surgery especially when excessive manipulation of the ICA is unavoidable. When performing intraoperative angiography for aneurysm surgery, it is prudent to detect any filling defect within the surrounding vessels.

Surgical treatment of large and giant cavernous carotid aneurysms

Cavernous carotid aneurysms (CCAs) are uncommon pathologic entities. Extradural place and the skull base location make this type of an aneurysm different in clinical features and treatment techniques. Direct aneurysm clipping is technically difficult and results in a significant postoperative neurological deficit. Therefore, several techniques of indirect surgical treatment were developed with different surgical outcomes, such as proximal occlusion of internal carotid artery (ICA) or trapping with or without bypass (superficial temporal artery-middle cerebral artery bypass or high-flow bypass). High-flow bypass with proximal ICA occlusion seems to be the most appropriate surgical treatment for CCA because of the high rate of symptom improvement, aneurysm thrombosis, and minimal postoperative complications. However, in cases of CCA presented with direct carotid-cavernous fistula, the appropriate surgical treatment is high-flow bypass with aneurysm trapping, which the fistula can be obliterated immediately after surgery.