12.1 History and Initial Description

There have been some reports about surgical treatment for patients with moyamoya disease involving hypoperfusion in the anterior cerebral artery (ACA) territory. Some procedures of indirect revascularization in the ACA territory were reported to help cases of moyamoya disease to prevent ischemic stroke. However, effectiveness of indirect revascularization has some limitations, taking several months to obtain its effect and having potentially insufficient effect compared to direct bypass. Superficial temporal artery–middle cerebral artery (STA–MCA) bypass may improve ischemia in both the ACA and the MCA territories through leptomeningeal anastomosis between capillary vessels of the ACA and the MCA. However, it’s unclear before operation whether blood supply in the ACA territory from STA–MCA bypass through leptomeningeal anastomosis is sufficient.

Previously, direct bypass in the ACA territory using the peripheral branch of the STA for the graft was conducted. We introduced new techniques using the long STA graft, which can allow wide blood supply from the bypass in 2010. Moyamoya patients who need reconstruction in the ACA territory also require frequently reconstruction in the MCA territory. In this chapter, we describe STA–ACA/MCA double bypasses with a long graft. This procedure has the potential for powerful revascularization that can provide blood supply in the whole frontal lobe.

12.2 Indications

The indication for STA–ACA/MCA bypasses with long grafts in cases of moyamoya disease are as follows: (1) hypoperfusion with poor vasoreactivity in the ACA and the MCA territories based on cerebral blood flow (CBF) study and angiographic study, and (2) ischemic symptoms including the lower extremities. A typical angiographic finding is severe internal carotid artery terminal stenosis/occlusion with poor collateral blood flow from ipsilateral posterior cerebral artery, contralateral ACA, or ipsilateral MCA.

12.3 Key Principle of STA–ACA/MCA Double Bypasses with Long Grafts

This procedure requires much time (about 5 hours) and takes a lot of effort, specifically a large skin incision with two separate craniotomies, long STA graft dissection, and anastomosis for small-size recipient artery. However, this procedure can achieve immediate blood supply from the bypasses in both ACA and MCA territories. Moreover, this powerful revascularization has the possibility to provide blood flow in the greater part of the frontal lobe (Fig. 12‑1 a, b).

12.4 SWOT Analysis

12.5 Contraindications

Contraindications to STA–ACA/MCA bypasses with long grafts are as follows: cases with insufficient STA development and young pediatric cases. There are probably 10 to 20% of cases where STAs are too small in size or too many in branching to be prepared as the long graft. In our experience of 62 cases, blood supply from bypasses has been commonly developing in the greater part of the frontal lobe. However, blood supply from bypasses that gradually shifted to indirect collaterals was shown particularly in pediatric cases less than 10 years old.