竞争血流与冠脉移植血管的相互作用

Relation Between Competitive Flow and Graft Flow in Coronary Artery Bypass Grafting

目的探讨竞争血流对冠脉移植血管血流量的影响。方法健康成年犬12只(体重27.62±1.63 kg),在非体外循环心脏不停跳下行冠状动脉旁路移植术(CABG),术中应用即时血流测量仪对不同的狭窄级别进行分组,分为无狭窄组,33%狭窄组、50%狭窄组和75%狭窄组,在相对恒定的血压和心率范围内,阻断和不阻断竞争血流时分别测量心率(HR)、平均动脉压(M AP)移植血管的血流量和搏动指数(P I)。结果在相对恒定的血压和心率范围内阻断竞争血流后各组的移植血管血流量均较不阻断竞争血流时明显升高。阻断和不阻断竞争血流时无狭窄组、33%狭窄组的P I均低于正常;50%狭窄组阻断竞争血流较不阻断竞争血流时P I下降(从8.36±3.52下降到3.02±0.94);75%狭窄组P I>5。结论竞争血流可抑制冠脉移植血管血流量,CABG中吻合点的选择将可能影响移植血管的通畅性。

Objective To study the relation between competitive flow and graft flow in coronary artery bypass grafting. Methods Twelve adult healthy dogs （weighing 27. 62 ± 1. 63 kg） were anesthetized and received offpump coronary artery bypass grafting. During operation, flow meter was used to measure the degree of stenosis, and according to which four groups were classified. They were： non-stenosis group, 33% stenosis group, 50% stenosis group and 75 % stenosis group. Hemodynamic parameters including flow volume of graft, pulsatility indes （PI）, heart rate（HR） and mean arterial pressure（MAP） were recorded with or without competitive flow. Results When there was a competitive flow, the flow volume of graft in all four groups was less than the flow volume of graft which has not been affected by competitive flow. PI of non-stenosis group and 33% stenosis group was lower than normal PI. 50% stenosis group PI decreased from 8. 36±3. 52 to 3. 02±0. 94; 75% stenosis group PI was more than 5. Conclusion Competitive flow will restrain the graft flow. The position of graft anastomosis may be affected graft＇s patency.