Factors of effective neovascularization after surgical treatment of moyamoya disease

Background. Moyamoya disease is a chronic cerebrovascular disease with complex pathophysiology. This disease is characterized by unique and unclear features of neoangiogenesis in natural course of disease and after surgical treatment. Natural collateral circulation was discussed in the first part of the article. Objective. To analyze the nature and degree of neoangiogenesis after combined revascularization in patients with moyamoya disease and to identify the factors of effective direct and indirect components. Material and methods. We analyzed 80 patients with moyamoya disease who underwent 134 surgical interventions. The main group consisted of patients after combined revascularization (79 operations), two control groups comprised patients after indirect (19) and direct (36) operations. We assessed postoperative MR data, function of each component of revascularization considering angiographic and perfusion modes and their contribution to the overall result of revascularization. Results. Factors of effective direct components of revascularization are large diameter of acceptor (p=0.028) and donor (p<0.0001) arteries, as well as double anastomoses (p=0.009). Factors of effective indirect synangiosis are younger age of patients (p=0.009), «ivy» symptom (p=0.005), enlargement of M4 branches of the MCA (p=0.026), transdural (p=0.004) and leptomeningeal (p=0.001) collaterals, use of more indirect components (p=0.027). Combined surgery provides the best angiographic (p=0.023) and perfusion (p<0.0001) results of revascularization. If one of the components is ineffective, other one ensures favorable result of surgery. Conclusion. Combined revascularization is preferable in patients with moyamoya disease. However, a differentiated approach involving the effectiveness of various components of revascularization should be taken into account when planning surgical tactics. Understanding the state of collateral circulation in patients with moyamoya disease both in natural course of disease and after surgical treatment opens the ways for their rational use.