Dr. Amol Raheja
MBBS, MCh, Skull Base and Cerebrovascular Fellow
Consultant and Assistant Professor, Neurosurgery 
All India Institute of Medical Sciences and Jai Prakash
Apex Trauma Center, New Delhi

 

Sanjeev A. Sreenivasan, Raghav Singla, Ashish Suri

Optimal management of complex anterior circulation aneurysms is an enigmatic challenge because of frequent involvement of major vessel bifurcation, choroidal vessels, and lenticulostriate/ thalamostriate perforators. Cerebral ischemia associated with prolonged clipping time is a major concern pertinent to their surgical management, especially in patients with poor cross flow across anterior and posterior communicating arteries. To circumvent this hurdle, single/ double barrel low-flow superficial temporal artery (STA) to middle cerebral artery (M3/M4-MCA)can be performed which can maintain distal cerebral perfusion while facilitating safe clip reconstruction of complex MCA and supraclinoidal internal carotid artery (ICA) aneurysms involving ICA bifurcation or supraclinoidal ICA aneurysms with poor cross circulation (Insurance bypass), as well as supplement/alter blood flow after MCA aneurysm trapping (Flow alteration bypass).

Retrospective chart review of consecutive neurosurgical patients operated during a period of 2 years (March 2016 – February 2018) at our tertiary care hospital. Patients with complex MCA and ICA aneurysms who were treated with STA-MCA bypass were included in this study. The clinical profile, pre and post operative images, intraoperative imaging, and patient outcomes were recorded and analyzed.

 

We present a series of five cases of complex aneurysms {MCA (4 cases) and supraclinoid ICA (1 case)} managed successfully using this strategy, which involved a total of 6 STA-MCA bypass procedures (Insurance bypass – 3, Flow-alteration bypass - 3). Surgical reconstruction of an aneurysm was the treatment of choice in view of the involvement of choroidal/ thalamostriate perforators, MCA/ICA bifurcation, complex aneurysm morphology, or dissecting/thrombosed nature of aneurysm. STA-MCA low-flow bypass was performed using M3/M4-segment of MCA as the recipient in anticipation of prolonged temporary clipping time on M1-MCA or in patients with supraclinoidal ICA aneurysms and poor cross flow, or need for possible trapping of fusiform MCA an aneurysm and aneurysm involving ICA terminus. The saccular/fusiform part of an aneurysm was clip reconstructed and the partially thrombosed dissecting segment was opened for thrombectomy and trapped using proximal and distal clips after good patency of bypass was confirmed. The distal MCA flow was restored adequately and confirmed intraoperatively using indocyanine green angiography and microdoppler ultrasonography. Post-operative check angiograms demonstrated patent bypass in all five patients. All the patients had excellent outcome (mRS score 0/1) till last known follow-up, except one (mRS score 4) who had recovering hemiparesis and aphasia.

 

This case series highlights the surgical strategy and safety for successfully managing complex MCA and ICA aneurysms using low-flow STA-MCA revascularization procedures.