High-Flow Bypass and Clip Trapping of a Giant Fusiform Middle Cerebral Artery (M1) Aneurysm: Technical Case Instruction

BACKGROUND AND IMPORTANCE

Giant intracranial aneurysms have a poor natural history with mortality rates of 68% and 80% over 2-year and 5-year, respectively. Cerebral revascularization can provide flow preservation while treating complex aneurysms requiring parent artery sacrifice. In this report, we describe the microsurgical clip trapping and high-flow bypass revascularization for a giant middle cerebral artery (MCA) aneurysm.

CLINICAL PRESENTATION

A 19-year-old man was diagnosed with a giant left MCA aneurysm after he suffered a left hemispheric capsular stroke 6 months ago. Since then, the patient recovered from the right hemiparesis and dysarthria with residual symptoms. Neuroimaging demonstrated a giant fusiform aneurysm encompassing the entire M1 segment. The bilobed aneurysm measured 37 × 16 × 15 mm. Endovascular treatment options included partial coiling of the aneurysm followed by deployment of flow-diverting stent spanning from the M2 branch-through the aneurysm neck-into the internal carotid artery. Because of the high risk of lenticulostriate artery stroke with endovascular treatment, the patient opted for microsurgical clip trapping and bypass. The patient consented to the procedure. High-flow bypass from internal carotid artery to M2 MCA was performed using radial artery graft, followed by aneurysm clip trapping using 3 clips.

CONCLUSION

We demonstrate the successful microsurgical treatment for a complex case of giant M1 MCA aneurysm with fusiform morphology. High-flow revascularization using radial artery graft helped in achieving good clinical outcome with complete aneurysm occlusion with flow preservation despite the challenging morphology and location. Cerebral bypass continues to be a useful tool to tackle complex intracranial aneurysms.

Microsurgical Clipping of Intracranial Aneurysms in the Endovascular Era

The treatment of intracranial aneurysms (IA) began in the late 19th century. Some degree of controversy has always surrounded the best treatment modality for IA. Cushing and Dandy debated about cervical carotid ligation as the only surgical alternative before the introduction of microsurgical clipping. In the early 21st century, the debate has centered on surgical versus^ endovascular techniques. With the advent of newer endovascular techniques and devices, there has been a dramatic shift in treatment paradigms toward endovascular intervention that is preferred by both physicians and patients. However, there will always be a need for microsurgical cerebrovascular expertise since some aneurysms cannot or should not be embolized. This creates a difficult conundrum as only the most complex of aneurysms will require open surgery, but the lack of volume and training will be a challenge in teaching and maintaining the surgical expertise required to safely treat them. The purpose of this review is to discuss the history of IA treatment and critically evaluate the current state of the art of IA treatment, with a specific focus on the necessary role microsurgical clipping continues to play in the current treatment landscape.