Clinical Scorecard: A Hybrid Minimally Invasive Approach for Treating Ruptured Dissecting Fusiform Aneurysms of the Proximal Posterior Inferior Cerebellar Artery: A Step-by-Step Guide

At a Glance

Key Highlights

• Proximal PICA aneurysms are deep-seated and challenging to access surgically, with up to 30% risk of lower cranial nerve deficits.
• A single-stage hybrid approach combining microsurgical PICA–PICA side-to-side bypass and endovascular coil embolization is feasible and effective.
• Intraoperative imaging techniques including indocyanine green videoangiography, micro-Doppler ultrasonography, and digital subtraction angiography confirm bypass patency and aneurysm obliteration.

Guideline-Based Recommendations

Diagnosis

• Use non-contrast CT to identify subarachnoid and intraventricular hemorrhage.
• Employ CT angiography and 3D angiography to detect and characterize dissecting fusiform aneurysms of the PICA.
• Perform intraoperative digital subtraction angiography to assess aneurysm anatomy and guide treatment.

Management

• Establish preemptive endovascular access via femoral artery sheath placement before microsurgery.
• Perform microsurgical PICA–PICA side-to-side bypass through a minimally invasive midline suboccipital craniotomy to preserve PICA flow.
• Conduct endovascular coil embolization of the aneurysm and proximal PICA segment in the same operative session to achieve complete aneurysm obliteration.

Monitoring & Follow-up

• Use intraoperative indocyanine green videoangiography and micro-Doppler ultrasonography to confirm bypass patency.
• Perform post-bypass angiography to verify aneurysm exclusion and PICA–PICA bypass function.
• Monitor for lower cranial nerve function given surgical manipulation risks.

Risks

• Potential for lower cranial nerve deficits due to arachnoid dissection and surgical exposure.
• Risk of PICA infarction if flow is not preserved during aneurysm treatment.
• Possible injury to brainstem perforators originating from the proximal PICA segment.

Patient & Prescribing Data

Patients with ruptured dissecting fusiform aneurysms of the proximal PICA requiring complex vascular reconstruction and aneurysm obliteration.

A combined hybrid approach with microsurgical bypass followed by endovascular coil embolization under a single anesthesia session optimizes aneurysm management and preserves critical PICA flow.

Clinical Best Practices

• Preoperatively evaluate surgical feasibility of PICA–PICA bypass considering vessel size and anatomical proximity.
• Secure endovascular sheath prior to repositioning patient to maintain access and reduce procedure time.
• Minimize cerebellar retraction during microsurgical exposure to reduce neurological morbidity.
• Use high magnification and fine suturing techniques (10–0 nylon) for precise vascular anastomosis.
• Confirm bypass patency intraoperatively before proceeding to endovascular embolization.
• Perform coil embolization under biplane fluoroscopy with roadmap guidance to ensure complete aneurysm occlusion.

References

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