Extracorporeal Life Support Center of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, 410011, China.
Department of Urology, Xiangya Hospital, Central South University, Changsha, 410008, China.
BMC Cardiovasc Disord. 2022 Dec 6;22(1):527. doi: 10.1186/s12872-022-02955-5.
Deep hypothermic circulatory arrest (DHCA) is commonly used in adult aortic surgery and pediatric complex congenital heart disease, and is associated with pathophysiological changes and postoperative complications. Here, a temperature-controlled circulatory arrest model in rats was established to study the suitable temperature of circulatory arrest by investigating the damage to body organs under different temperatures.
Thirty Sprague‒Dawley rats were randomly divided into 5 equal groups for DHCA experiments: I (15-20 °C), II (20-25 °C), III (25-30 °C), IV (normothermic cardiopulmonary bypass), and V (sham operation group). Blood gas analysis, homodynamic parameters, and intervals of cardiac recovery were measured at different time points in all groups. Morphological changes in intestinal tissue were observed under light and electron microscopes. Oxidative stress was measured by MPO activity, MDA, and SOD content. Tissue damage was confirmed by serum detection of ALT, AST, BUN, Cr, and LDH. To examine the inflammatory response, cytokines, including IL-1, IL-4, IL-10, IFN-γ, and TNF-α, were detected.
The extracorporeal circulation technique caused damage to the body; the degree of the damage caused by the circulatory arrest technique may be related to circulating temperature, with the least amount of damage occurring at 20-25 °C compared to 15-20 °C and 25-30 °C. Ischemia and hypoxia can cause intestinal tissue damage, which manifests primarily as a loss of the intestinal mucosal barrier. Ischemic intestinal damage caused by DHCA was not associated with inflammation.
The study provides new insights into the pathophysiologic mechanisms of DHCA.
深低温停循环（DHCA）常用于成人主动脉手术和儿科复杂先天性心脏病，与病理生理变化和术后并发症有关。本研究通过在不同温度下研究器官损伤，建立大鼠温度控制停循环模型，以研究停循环的合适温度。
30 只 Sprague-Dawley 大鼠随机分为 5 个 DHCA 实验相等组：I（15-20°C）、II（20-25°C）、III（25-30°C）、IV（常温心肺转流）和 V（假手术组）。在所有组中，在不同时间点测量血气分析、血液动力学参数和心脏恢复间隔。在光镜和电子显微镜下观察肠组织的形态变化。通过 MPO 活性、MDA 和 SOD 含量测量氧化应激。通过 ALT、AST、BUN、Cr 和 LDH 血清检测确定组织损伤。为了检测炎症反应，检测了细胞因子，包括 IL-1、IL-4、IL-10、IFN-γ和 TNF-α。
体外循环技术对机体造成损伤；停循环技术造成的损伤程度可能与循环温度有关，与 15-20°C 和 25-30°C 相比，20-25°C 时损伤最小。缺血缺氧会导致肠组织损伤，主要表现为肠黏膜屏障丧失。DHCA 引起的缺血性肠损伤与炎症无关。
本研究为 DHCA 的病理生理机制提供了新的见解。
