Objective: To investigate the use of a saphenous vein graft for bypass of the external carotid artery (ECA) to supraclinoid internal carotid artery (ICA) when the proximal middle cerebral artery (MCA) is not suitable for a bypass procedure.
Material and methods: Five adult cadaver sides were used. Dissection required a frontotemporal craniotomy and a zygomatic arch osteotomy, with a hole being opened 2-3 mm lateral to the foramen rotundum extradurally. The ECA was found easily via a second incision in the cervical region. The ophthalmic segment of the ICA was exposed by removal of the anterior clinoid process intradurally. After the dura over the hole was opened, the 7-8-cm long bypass graft was passed just behind the mandibula and through the hole inside the dura to reach the ICA. The ECA was then transected proximal to the occipital artery (OA) branch and the distal side of the vein graft was anastomosed end-to-end with the ECA and end-to-side with the supraclinoid ICA.
Results: The mean diameter of the ECA proximal to the OA was 3.75+/-0.4 mm (range 3.35-4.15 mm) and that of the supraclinoid ICA was 3.4+/-0.5 mm (range 2.9-3.9 mm). The mean length of the venous graft was 7.5+/-0.5 cm (range 7-8 cm).
Conclusion: When high blood flow is needed and the proximal MCA is not suitable for a bypass, the bypass described herein may be an alternative to a superficial temporal to MCA bypass as well as to extracranial carotid artery to MCA or ICA bypasses, which both need long vein grafts.