即时血流测量技术在冠脉旁路移植术中的应用研究

Role of Transit-time Flow Measurement during Off-pump Coronary Artery Bypassing

目的:评价即时血流测量技术检测冠脉移植桥通畅性的应用价值.方法:在非体外循环心脏不停跳中行搭桥手术,术中应用即时血流测量仪测量移植桥流量,并对搏动指数和血流波形进行分析.结果:(1)不阻断竞争血流时无狭窄组和50%狭窄、75%狭窄组间的差异有统计学意义.无狭窄组和33%狭窄组血流波形是“舒张期优势型”,两组搏动指数低于标准搏动指数(PI=5).随着狭窄的加重,50%狭窄组、75%狭窄组桥血流波形变成以收缩期为主,出现高而尖的收缩期波形,舒张期波形低平;搏动指数大于5·0.(2)阻断竞争血流后各组的桥血流量明显上升.阻断竞争血流后50%狭窄组血流波形改善为舒张期优势型,搏动指数降至(3·02±0·94);而75%狭窄组桥血流波形仍然以收缩期为主,收缩期波形高而尖,舒张期波形低平;搏动指数大于5·0.结论:即时血流测量在冠状动脉搭桥术中可检测出≥75%的狭窄.

Objective:To assess evaluate the accuracy of TTM to find out the stenosis of coronary artery anastomasis . Methods:Twelve adult healthy dogs of both sexes weighing (27.62±1.63)kg were anesthetized and their chests were opened with a medial sternotomy, There are four groups produced with four catheters divded in non-stenosis,33% stenosis,50% stenosis and 75% stenosis. Hemodynamic parameters including flow volume of graft,PI,wave of flow,heart rate(HR),blood pressure(BP),central venous pressure(CVP) were recorded . Results:(1) When there is a competitive flow, the flow volume of graft is less than the flow volume of graft which has not been affected by competitive flow in all four groups.(2) The flow volume of non-stenosis' graft is equare to 33% stenosis's, P<0.05. The flow volume of non-stenosis' graft is more than 50% stenosis's and 75% stenosis's, P<0.05.The flow volume of 33% stenosis is more than 50% stenosis's and 75% stenosis's, P<0.05.The flow volume of 50% stenosis' graft is more than 75% stenosis's, P<0.05.(3) When competitive flow have been occluded , the flow volume of graft of non-stenosis, 33% stenosis and 50% stenosis are more than 20mL/min. But the flow volume of graft of 75% stenosis is low. Conclusion Transit-time flow meter can provide a suitable measurement for intraoperative assessment of coronary graft patency.