Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah; Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah.
Department of Cardiac Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
Heart Rhythm. 2020 Dec;17(12):2200-2207. doi: 10.1016/j.hrthm.2020.07.008. Epub 2020 Jul 10.
Postoperative conduction block requiring lifetime pacemaker placement continues to be a considerable source of morbidity for patients undergoing repair of congenital heart defects. Damage to the cardiac conduction system (CCS) during surgical procedures is thought to be a major cause of conduction block. Intraoperative identification and avoidance of the CCS is thus a key strategy to improve surgical outcomes. A number of approaches have been developed to avoid conduction tissue damage and mitigate morbidity. Here we review the historical and contemporary approaches for identification of conduction tissue during cardiac surgery. The established approach for intraoperative identification is based on anatomic landmarks established in extensive histologic studies of normal and diseased heart. We focus on landmarks to identify the sinus and atrioventricular nodes during cardiac surgery. We also review technologies explored for intraoperative tissue identification, including electrical impedance measurements and electrocardiography. We describe new optical approaches, in particular, and optical spectroscopy and fiberoptic confocal microscopy (FCM) for identification of CCS regions and working myocardium during surgery. As a template for translation of future technology developments, we describe research and regulatory pathways to translate FCM for cardiac surgery. We suggest that along with more robust approaches to surgeon training, including awareness of fundamental anatomic studies, optical approaches such as FCM show promise in aiding surgeons with repairs of heart defects. In particular, for complex defects, these approaches can complement landmark-based identification of conduction tissue and thus help to avoid injury to the CCS due to surgical procedures.
术后传导阻滞需要终身起搏器植入仍然是接受先天性心脏缺陷修复的患者相当大的发病率来源。手术过程中心脏传导系统 (CCS) 的损伤被认为是传导阻滞的主要原因。因此，术中识别和避免 CCS 是改善手术结果的关键策略。已经开发了许多方法来避免传导组织损伤并减轻发病率。在这里，我们回顾了心脏手术中识别传导组织的历史和当代方法。术中识别的既定方法基于对正常和患病心脏进行广泛组织学研究确定的解剖学标志。我们专注于识别心脏手术中心房和房室结的标志。我们还回顾了用于术中组织识别的技术，包括电阻抗测量和心电图。我们描述了新的光学方法，特别是用于识别 CCS 区域和手术中工作心肌的光学光谱和光纤共聚焦显微镜 (FCM)。作为未来技术发展的翻译模板，我们描述了用于心脏手术的 FCM 转化的研究和监管途径。我们认为，除了更强大的手术医生培训方法外，包括对基本解剖研究的认识，光学方法（如 FCM）在帮助外科医生修复心脏缺陷方面显示出前景。特别是对于复杂的缺陷，这些方法可以补充基于标志的传导组织识别，从而有助于避免因手术程序导致 CCS 损伤。
