Postoperative angiography and Doppler - Ultrasonic examination showed shunt patency in 90% of cases. Partial shunt thrombosis occurred in 2 cases in PTFE graft without supporting rings.
Results Among the 87 lying in women traced by B ultrasonography examination, 2 were placenta lower, 2 were marginal placenta previa, 3 were partial placenta previa and 5 were complete placenta previa.
This paper mainly discusses the operation principle of hydraulic disc brake, the constitution of on-line examination and the designs of electric circuit, machine and software partial.