Internal Maxillary Artery-Middle Cerebral Artery Bypass: Infratemporal Approach for Subcranial-Intracranial (SC-IC) Bypass

Nossek, Erez MD*; Costantino, Peter D. MD‡,§; Eisenberg, Mark MD*; Dehdashti, Amir R. MD*; Setton, Avi MD*; Chalif, David J. MD*; Ortiz, Rafael A. MD‡,§; Langer, David J. MD‡,§

doi: 10.1227/NEU.0000000000000340
Concepts, Innovations and Techniques

BACKGROUND: Internal maxillary artery (IMax)–middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical extracranial-intracranial bypass. This technique uses a “keyhole” craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis.

OBJECTIVE: To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass.

METHODS: Orbitozygomatic osteotomy is used followed by frontotemporal craniotomy and subsequently laterotemporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomic landmarks, neuronavigation, and micro Doppler probe (Mizuho Inc. Tokyo, Japan). Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass.

RESULTS: There were 4 cases in which the technique was used. One bypass was performed for flow augmentation in a hypoperfused hemisphere. The other 3 were performed as part of treatment paradigms for giant middle cerebral artery aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in 1 patient and end-to-end in 3 patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20 to 60 mL/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well.

CONCLUSION: IMax to middle cerebral artery subcranial-intracranial bypass is safe and efficacious. The laterotemporal fossa craniectomy technique resulted in reliable identification and wide exposure of the IMax, facilitating the proximal anastomosis.

ABBREVIATIONS: EC-IC, extracranial-intracranial

IMax, internal maxillary artery

MCA, middle cerebral artery

SC-IC, subcranial-intracranial

STA, superficial temporal artery

*Department of Neurosurgery, North Shore - Long Island Jewish/Hofstra School of Medicine North Shore University Hospital, Manhasset, NY;

Department of Neurosurgery, North Shore - Long Island Jewish/Hofstra School of Medicine North Shore University Hospital Lenox Hill Hospital; New York, NY;

§The New York Head & Neck Institute, North Shore- Long Island Jewish/Hofstra School of Medicine Lenox Hill Hospital, New York, NY

Correspondence: David Langer, MD, Department of Neurosurgery, North Shore–Long Island Jewish Health System, Lenox Hill Hospital, 130 E. 77th Street, New York, NY 10075. E-mail:

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.

Received January 07, 2014

Accepted February 14, 2014

Copyright © by the Congress of Neurological Surgeons