对于胸廓内动脉（ITA）灌注不足的情况，辅助静脉移植物应吻合在胸廓内动脉的上游还是下游？

Otaki M, Inoue T, Oku H

Department of Cardiovascular Surgery, Kinki University Hospital, Osaka, Japan.

J Cardiovasc Surg (Torino). 2001 Dec;42(6):793-7.

BACKGROUND

This study was designed to compare internal thoracic artery (ITA) flow in different settings of supplemental vein grafting for ITA hypoperfusion.

METHODS

Fourteen dogs each received two coronary bypass grafts to the circumflex artery (CFX), using left ITA and vein grafts, and then the proximal CFX was ligated. The animals were divided into two groups. G-I dogs receiving the vein graft proximally to the ITA graft and G-II receiving the vein distally. ITA flow was evaluated regarding 1) effects of competition from the vein graft, and 2) pharmacological or physiological effects on the ITA's contribution to distal perfusion. Flow is expressed as a mean (ml/min).

RESULTS

ITA flow was 44.2+/-5.9 in G-I, and 45.7+/-6.5 in G-II (p=ns), when the vein graft was occluded. With a vein graft open, ITA flow decreased to 7.5+/-1.6 in G-I, and 6.8+/-1.8 in G-II (p=ns), and ITA's contribution to total perfusion requirements was 18% in G-I and 16% in G-II. Adenosine (0.2 mg/min/kg) increased the ITA flow in both groups, 18.4+/-3.2, and 16.3+/-3.8, respectively (p=ns), and ITA's contribution to distal perfusion was increased to 32% in G-I and 27% in G-II. In contrast, phenylephrine (0.003 mg/min/kg) decreased ITA flow and ITA's contribution to distal flow in both groups (6.1+/-1.1, 11% vs 6.2+/-1.4, 11%, p=ns), but increased vein flow significantly. Cardiac pacing (150 bpm) increased the ITA flow and ITA's contribution to distal perfusion equally in both groups (8.4+/-1.5, 16% vs 7.6+/-2.6, 15%, p=ns).

CONCLUSIONS

Supplemental vein grafting, whether it is placed distally or proximally, limits ITA flow and ITA's contribution to distal perfusion both in the resting heart and during the increased myocardial oxygen demand.

背景

本研究旨在比较在不同的补充静脉移植设置下，用于胸廓内动脉（ITA）灌注不足时的ITA血流情况。

方法

14只犬每只接受两根冠状动脉搭桥至左旋支动脉（CFX），使用左ITA和静脉移植物，然后结扎CFX近端。动物被分为两组。I组犬在ITA移植物近端接受静脉移植物，II组在远端接受静脉移植物。评估ITA血流的情况包括：1）来自静脉移植物竞争的影响，以及2）对ITA对远端灌注贡献的药理或生理影响。血流以平均值（ml/min）表示。

结果

当静脉移植物闭塞时，I组的ITA血流为44.2±5.9，II组为45.7±6.5（p=无显著性差异）。静脉移植物开放时，I组的ITA血流降至7.5±1.6，II组为6.8±1.8（p=无显著性差异），且ITA对总灌注需求的贡献在I组为18%，II组为16%。腺苷（0.2mg/min/kg）使两组的ITA血流均增加，分别为18.4±3.2和16.3±3.8（p=无显著性差异），且ITA对远端灌注的贡献在I组增加至32%，II组增加至27%。相比之下，去氧肾上腺素（0.003mg/min/kg）使两组的ITA血流和ITA对远端血流的贡献均降低（6.1±1.1，11%对6.2±1.4，11%，p=无显著性差异），但显著增加了静脉血流。心脏起搏（150次/分钟）使两组的ITA血流和ITA对远端灌注的贡献均同等增加（8.4±1.5，16%对7.6±2.6，15%，p=无显著性差异）。