Dora Kim A, Stanley Christopher P, Al Jaaly Emad, Fiorentino Francesca, Ascione Raimondo, Reeves Barnaby C, Angelini Gianni D
Department of Pharmacology, University of Oxford, United Kingdom
Department of Pharmacology, University of Oxford, United Kingdom.
J Am Heart Assoc. 2016 Feb 23;5(2):e002822. doi: 10.1161/JAHA.115.002822.
Pulmonary dysfunction is a known complication after cardiac surgery using cardiopulmonary bypass, ranging from subclinical functional changes to prolonged postoperative ventilation, acute lung injury, and acute respiratory distress syndrome. Whether human pulmonary arterial function is compromised is unknown. The aim of the present study was to compare the structure and function of isolated and cannulated human pulmonary arteries obtained from lung biopsies after the chest was opened (pre-cardiopulmonary bypass) to those obtained at the end of cardiopulmonary bypass (post-cardiopulmonary bypass) from patients undergoing coronary artery bypass graft surgery.
Pre- and post-cardiopulmonary bypass lung biopsies were received from 12 patients undergoing elective surgery. Intralobular small arteries were dissected, cannulated, pressurized, and imaged using confocal microscopy. Functionally, the thromboxane mimetic U46619 produced concentration-dependent vasoconstriction in 100% and 75% of pre- and post-cardiopulmonary bypass arteries, respectively. The endothelium-dependent agonist bradykinin stimulated vasodilation in 45% and 33% of arteries pre- and post-cardiopulmonary bypass, respectively. Structurally, in most arteries smooth muscle cells aligned circumferentially; live cell viability revealed that although 100% of smooth muscle and 90% of endothelial cells from pre-cardiopulmonary bypass biopsies had intact membranes and were considered viable, only 60% and 58%, respectively, were viable from post-cardiopulmonary bypass biopsies.
We successfully investigated isolated pulmonary artery structure and function in fresh lung biopsies from patients undergoing heart surgery. Pulmonary artery contractile tone and endothelium-dependent dilation were significantly reduced in post-cardiopulmonary bypass biopsies. The decreased functional responses were associated with reduced cell viability.
URL: http://www.isrctn.com/ISRCTN34428459. Unique identifier: ISRCTN 34428459.
肺功能障碍是体外循环心脏手术后已知的并发症，范围从亚临床功能改变到术后通气时间延长、急性肺损伤和急性呼吸窘迫综合征。人类肺动脉功能是否受损尚不清楚。本研究的目的是比较冠状动脉搭桥手术患者在开胸后（体外循环前）肺活检获得的分离并插管的人肺动脉与体外循环结束时（体外循环后）获得的肺动脉的结构和功能。
从12例行择期手术的患者获取体外循环前后的肺活检组织。解剖小叶内小动脉，插管，加压，并使用共聚焦显微镜成像。在功能上，血栓素类似物U46619分别在100%和75%的体外循环前和体外循环后的动脉中产生浓度依赖性血管收缩。内皮依赖性激动剂缓激肽分别在45%和33%的体外循环前和体外循环后的动脉中刺激血管舒张。在结构上，大多数动脉中的平滑肌细胞呈周向排列；活细胞活力显示，尽管体外循环前活检组织中100%的平滑肌细胞和90%的内皮细胞具有完整的细胞膜并被认为是活的，但体外循环后活检组织中分别只有60%和58%是活的。
我们成功地研究了心脏手术患者新鲜肺活检组织中分离的肺动脉结构和功能。体外循环后活检组织中肺动脉的收缩张力和内皮依赖性舒张明显降低。功能反应降低与细胞活力降低有关。
网址：http://www.isrctn.com/ISRCTN34428459。唯一标识符：ISRCTN 34428459。
