gms | German Medical Science

Objective: Patients suffering from cerebrovascular hemodynamic compromise utilize numerous intracranial collateralization pathways to improve cerebral blood supply. In Moyamoya patients pericallosal anastomosis (PA) is frequently observed. However, the clinical relevance of PA is unknown. It was the aim to analyse PA in patients with hemodynamic compromise.

Method: Hemodynamic compromise was verified using acetazolamide-stimulated Xenon-CT or SPECT in 55 patients(30 Moyamoya patients “MM”, 25 patients with atherosclerotic cerebrovascular disease “ACVD”). Digital subtraction angiography was performed prior to cerebral revascularization and after surgery (7 days). PA was graded according to angiographic criteria: grade I = filling of A5 and A4 segment with cortical branches; grade II = filling of A3 segment with cortical branches; grade III = filling of complete anterior circulation via pericallosal anastomosis. Patients that received DSA due to non-ruptured intracranial aneurysm (30 patients) served as hemodynamically healthy control patients. Logistic regression and Receiver Operating Characteristics analysis were performed to assess differences.

Results: PA of grade 2 or larger was observed in 28 out of 30 MM and only in 2 out of 25 ACVD patients. In healthy control patients no PA was observed. PA of grade 2 revealed a sensitivity of 88% (CI = 72%-97%) and a specificity of 92% (CI = 75%-99%) assessing MM vasculopathy. The area under the ROC curve was 0.94 (p < 0.001, CI = 0). Bilateral PA (sum of both grades ≥ 4) demonstrates a positive predictive value of 100% (CI: 82%-100%) with a sensitivity of 61% (CI: 42%-77%).

Conclusions: PA extending to the A3 segment or beyond indicates MM vasculopathy in adult patients. This may represent a MM specific collateralization pathway.