Relative contributions of the middle meningeal artery and superficial temporal artery in revascularization surgery for moyamoya syndrome in children: the results of superselective angiography

Abstract

Object: The authors used postoperative superselective angiography to assess the relative contributions of the middle meningeal artery (MMA) and the superficial temporal artery (STA) to revascularization following surgery for moyamoya syndrome in children.

Methods: Using the neurosurgical database at the Hospital for Sick Children, the authors reviewed the clinical and pre- and postoperative angiographic records obtained in patients with moyamoya syndrome undergoing superselective angiography. Patients were 16 years of age or younger and were undergoing revascularization surgery for moyamoya syndrome during the study period. Lateral internal carotid artery, external carotid artery, STA, and MMA angiograms were analyzed in the late arterial phase to assess the relative contributions of the STA and MMA to overall revascularization as determined by the external carotid artery injection.

Results: The total moyamoya surgical revascularization experience at the Hospital for Sick Children over a 12-year period (May 1996-December 2008) comprised 33 patients (20 girls and 13 boys) undergoing a total of 50 craniotomies. A decision was made in 2001 to perform superselective angiography postoperatively in patients with moyamoya syndrome. Superselective angiography was identified to have been performed postoperatively in 12 patients and 18 treated hemispheres, and it demonstrated that the MMA contributed more significantly than the STA in 11 (61%) of the 18 hemispheres. Seven patients were Asian, 3 patients had neurofibromatosis Type 1, 1 had Down syndrome, and 2 had no apparent risk factors (1 patient was Asian and had neurofibromatosis Type 1). Stroke had occurred in 58% of patients and transient ischemic attacks in 50% prior to surgery. Within the first 30 days of surgery, there were 2 episodes of stroke (11.7% per surgically treated hemisphere and 18.2% per patient). Seventy-eight percent of hemispheres surgically treated exhibited excellent revascularization (Matsushima Grade A) on follow-up angiography, and there were no strokes documented in any patients more than 1 month after surgery, in a long-term follow-up of mean 4.1 years.

Conclusions: The contributions of the MMA to revascularization after pial synangiosis for moyamoya syndrome are significant and may frequently exceed the contribution of the STA when surgery is performed with preservation of dural vasculature and dural inversion.