Dissecting aneurysm of vertebral artery involving the origin of posteroinferior cerebellar artery treated with retrograde stent placement and coil embolization in the era of flow diverter

Uncommon Cause, Critical Consequence: Vertebral Artery Aneurysm Resulting in Intraventricular Hemorrhage

The vertebrobasilar system is made up of the two vertebral arteries that unite to form the basilar artery near the base of the skull. Aneurysms in the vertebrobasilar system are distinct from other cerebral aneurysms due to their unique morphologic characteristics. They can be large and bulging (massive), pressing on the brainstem. Alternatively, they might be weak and splitting apart (dissecting) or have an elongated shape (fusiform). On the other end of the spectrum, Vertebral artery aneurysms (VAAs) can also be small and rounded (saccular). These aneurysms can occur at the vertebral artery itself or where it joins the posterior inferior cerebellar artery (PICA). Anatomically, they are situated near the brainstem and cranial nerves, deep within the posterior fossa. The cerebrospinal fluid is kept in transit and flux by the ventricular system's chambers circulating the fluid within themselves. An intraventricular hemorrhage (IVH) can occasionally result from vertebral artery aneurysmal ruptures that result in bleeding into the subarachnoid space and then extravasate into the ventricles. Persistent and poorly controlled hypertension affects about 50% of individuals with IVH. In this case report, we study a 74-year-old woman who complained of a sudden onset headache that had been bothering her for three days at the medical emergency room. She had been diagnosed with systemic hypertension eight years prior and had not taken her medicines as prescribed. She was discovered to have rigidity in her neck and a blood pressure reading of 170/100 mmHg, which had been followed by an episode of vomiting. Radiological investigations revealed a VAA that had a high risk of rupturing and causing an IVH.

Microsurgical partial trapping for the treatment of unclippable vertebral artery aneurysms: Experience from 27 patients and review of literature

BACKGROUND

The efficacy and safety of partial trapping for the treatment of unclippable vertebral artery aneurysms (UVAs) are still questionable. The partial trapping method (proximal or distal occlusion) was used in the treatment of aneurysms to simplify the surgical procedure and avoid postoperative complications.

METHODS

This study included 27 patients with UVAs who underwent microsurgical partial trapping between January 2015 and August 2022, and their postoperative outcomes and complications were retrospectively reviewed and evaluated.

RESULTS

Ruptured UVAs were detected in 25 (92.6%) patients, and 13 (48.1%) patients had poor-grade status. Fusiform dissection, dissecting, and fusiform aneurysms were observed in 17 (63%), 7 (25.9%), and 3 (11.1%) patients, respectively. By location, preposterior inferior cerebellar artery (PICA), PICA, post- PICA, and non-PICA types were noted in 7 (25.9%), 9 (33.3%), 6 (22.2%), and 5 (18.5%) patients, respectively. Microsurgical partial trapping was performed in all patients (blind-alley formation in 96.3%). Complete aneurysm obliteration was achieved in 26 (96.3%) patients. Immediate complete obliteration was achieved in 21 (77.8%) patients, delayed thrombosis within 7 days in 5 (18.5%), and nearly complete obliteration in 1 (3.7%). No re-bleeding was detected in all patients. Favorable outcomes 3 months after the operation were achieved by 92.9% of the patients in the good-grade group and 85.2% overall.

CONCLUSIONS

Microsurgical partial trapping, especially the blind-alley formation technique, was a safe and effective treatment of UVAs with high rates of aneurysm thrombosis. The appropriate sites for clip occlusion were dependent on the angioarchitecture of UVAs.