[Experimental simulation study on EC-IC bypass: Part 2, Hemodynamics of superficial temporal artery and clinical application of the stenosis model].

In the preceding paper, Part 1, hemodynamics of the internal carotid artery stenosis and their changes after EC-IC bypass have been simulated and discussed in hydraulic and theoretical vascular models. In this study, theoretical model simulation has been advanced and applied to evaluate possible hemodynamic changes due to systemic blood pressure drop and to discuss the difference in efficacy between bypass and pressure elevation for its treatment. Dimensions of the STA have been referred to sometimes in relation to the technical problems for anastomosis but rarely for its cut bypass flow values. A hydraulic model of the STA has been manufactured with silicone and glass tubes to determine the relations between dimensions and cut bypass flow of STA. This was done because cut bypass flow is one of the important factors to be considered when speculating bypass capacity. STA main trunk is assumed to be 50 mm in length and 2 mm in inner diameter, and its branches reaching anastomosis sites about 40 mm in length. Effects of such factors as number of branches (single or double anastomosis), inner diameter and length are measured in this model to determine their effects on STA cut flow. In addition to these two problems, cortical arterial pressure and STA bypass flow are measured and compared to each other to determine in what hemodynamic conditions EC-IC bypass should be performed.(ABSTRACT TRUNCATED AT 250 WORDS)