猪非体外循环模型中临时腔内分流的慢性超微结构效应

Wippermann Jens, Albes Johannes M, Bruhin Raimund, Hartrumpf Martin, Vollandt Rüdiger, Kosmehl Hartwig, Wahlers Thorsten

Department of Cardiothoracic and Vascular Surgery, University Hospital Jena, Erlanger Allee 101, 07747 Jena-Lobeda, Germany.

Ann Thorac Surg. 2004 Aug;78(2):543-8. doi: 10.1016/j.athoracsur.2004.02.099.

BACKGROUND

Temporary intraluminal shunts (TILS) are routinely used in off-pump revascularization to facilitate the anastomosis while maintaining myocardial blood supply. Whereas tourniquet-occlusion can cause vessel wall trauma, potentially adverse chronic effects of TILS on the coronary intima have not been evaluated yet. This chronic large animal study investigated ultrastructural effects of TILS on the vessel wall.

METHODS

Four groups of acute and chronic pigs with either tourniquet-occlusion (TOUR) or TILS (40 kg; acute, n = 12; chronic, n = 20) were analyzed. Animals underwent median sternotomy, heparin (150 U/kg) administration, and left anterior descending coronary artery exposure. In groups with TOUR the left anterior descending coronary artery was temporarily occluded (10 minutes) with a tourniquet. In groups with TILS a silicone shunt (1.5 mm diameter, 12 mm length) was placed in the left anterior descending coronary artery more than 10 minutes and then removed, and the insertion was repaired. Thirty minutes after reperfusion all acute animals were sacrificed whereas chronic animals were extubated, maintained for 3 months, and then sacrificed. The left anterior descending coronary artery regions of occlusion or placement of the TILS silicone bulbs were examined histopathologically by scanning and transmission electron microscopy by a blinded pathologist.

RESULTS

In both acute and chronic investigations animals in the TILS group exhibited significantly less morphologic damage than animals in the TOUR group. In the acute phase significantly more loss of cell junction (p = 0.037), loss of endothelium (p = 0.032), and intimal edema (p = 0.037) in the TOUR group than in the TILS group was observed. Three months later, characteristic features with a changed pattern were detected: vacuolization of the cell (p = 0.03), loss of cell junction (p = 0.042), and removal of basal membrane (p = 0.046) as well as extensive loss of endothelium (p = 0.003) in the TOUR group compared with the TILS group.

CONCLUSIONS

Intimal lesions occur with both maneuvers early and late. However, animals in the TOUR group exhibited injuries significantly more often and more severely. Therefore, acute and chronic intimal integrity of the coronary vessel may be better preserved using TILS and may thus have a positive impact on the extent of de novo stenosis and long-term prognosis of the revascularized region.

背景

临时腔内分流术（TILS）常用于非体外循环血管重建术中，以利于吻合同时维持心肌血供。虽然止血带阻断会导致血管壁损伤，但TILS对冠状动脉内膜潜在的不良慢性影响尚未得到评估。这项慢性大型动物研究调查了TILS对血管壁的超微结构影响。

方法

分析四组急性和慢性猪，分别采用止血带阻断（TOUR）或TILS（40千克；急性，n = 12；慢性，n = 20）。动物接受正中胸骨切开术、给予肝素（150 U/kg）并暴露左前降支冠状动脉。在TOUR组中，用止血带暂时阻断左前降支冠状动脉（10分钟）。在TILS组中，将硅胶分流器（直径1.5毫米，长度12毫米）置于左前降支冠状动脉内超过10分钟，然后取出，并修复插入部位。再灌注30分钟后，所有急性动物被处死，而慢性动物拔管，维持3个月，然后处死。由一位不知情的病理学家通过扫描和透射电子显微镜对TILS硅胶球囊阻塞或放置部位的左前降支冠状动脉区域进行组织病理学检查。

结果

在急性和慢性研究中，TILS组动物的形态学损伤均明显少于TOUR组动物。在急性期，观察到TOUR组的细胞连接丧失（p = 0.037）、内皮丧失（p = 0.032）和内膜水肿（p = 0.037）明显多于TILS组。三个月后，检测到特征性的改变模式：与TILS组相比，TOUR组出现细胞空泡化（p = 0.03）、细胞连接丧失（p = 0.042）、基底膜消失（p = 0.046）以及广泛的内皮丧失（p = 0.003）。