Section of Cardiac Surgery, Cardiovascular Center 5144, University of Michigan, Ann Arbor, MI 48109-5864, USA.
J Thorac Cardiovasc Surg. 2012 Aug;144(2):334-9. doi: 10.1016/j.jtcvs.2011.09.026. Epub 2011 Nov 3.
Right thoracotomy using ventricular fibrillation with cooling has been used for redo mitral valve surgery. This approach avoids the complications of redo sternotomy, such as injury to prior grafts and hemorrhage. As a further refinement, we have used a beating heart technique to further minimize complications while simplifying the operation.
We reviewed the outcomes of 450 patients who underwent redo mitral valve surgery via a right thoracotomy from 1996 to 2011 at the University of Michigan. Of these, 134 patients underwent redo mitral valve surgery with ventricular fibrillation, and 316 patients underwent beating heart surgery. Although operative eras were consecutive, patients' age, risk factors, New York Heart Association, and preoperative left ventricular ejection fraction were not significantly different. Core temperature on cardiopulmonary bypass for beating heart surgery was 32°C versus 26°C for ventricular fibrillation.
Patients undergoing beating heart surgery had shorter periods of cardiopulmonary bypass: 81±9 minutes versus 113±36 minutes. Beating heart surgery required less blood products than ventricular fibrillation: 1.65±2 units versus 3.8±5 units packed red blood cells, 0.6±1.2 units versus 1.8±4 units fresh-frozen plasma, and 1.02±4 versus 7.5±17 platelet packs (all P<.01). Conversely, patients receiving ventricular fibrillation required longer postoperative ventilation: 34±101 hours versus 15.5±27 hours (P<.01). The 30-day mortality was similar for both (6.5% for beating heart and 7.4% for ventricular fibrillation), and postoperative length of stay was the same at 7 days. Stroke rate was 2.6% for patients undergoing beating heart surgery and 3% for patients receiving ventricular fibrillation. Significant operative complications were uncommon; there was no catastrophic hemorrhage, and only 2 patients receiving ventricular fibrillation and 2 patients undergoing beating heart surgery required reexploration.
As reoperative cardiac surgery continues to increase, techniques that safely facilitate operation while improving outcome should be adopted. As an operative alternative, redo right thoracotomy mitral valve surgery on the beating heart is associated with shorter bypass time, less transfusion requirements, shorter postoperative ventilation, and lower mortality. This safe and effective approach should be considered for this complex operation.
右开胸体外循环下室颤降温法已用于二尖瓣再次手术。这种方法避免了再次开胸的并发症，如先前移植血管的损伤和出血。作为进一步的改进，我们使用心脏不停跳技术进一步将并发症最小化，同时简化手术操作。
我们回顾了密歇根大学 1996 年至 2011 年期间 450 例因二尖瓣再次手术而行右开胸的患者的结局。其中，134 例患者因室颤行二尖瓣再次手术，316 例患者行心脏不停跳手术。尽管手术时代是连续的，但患者的年龄、危险因素、纽约心功能分级和术前左心室射血分数无显著差异。心脏不停跳手术的体外循环核心温度为 32°C，室颤组为 26°C。
行心脏不停跳手术的患者体外循环时间更短：81±9 分钟 vs 113±36 分钟。心脏不停跳手术比室颤组输血量更少：红细胞悬液 1.65±2 单位 vs 3.8±5 单位，新鲜冰冻血浆 0.6±1.2 单位 vs 1.8±4 单位，血小板 1.02±4 单位 vs 7.5±17 单位（均 P<.01）。相反，室颤组患者术后需要更长时间的机械通气：34±101 小时 vs 15.5±27 小时（P<.01）。两组患者 30 天死亡率相似（心脏不停跳组 6.5%，室颤组 7.4%），术后住院时间相同（7 天）。心脏不停跳组患者的脑卒中发生率为 2.6%，室颤组为 3%。严重手术并发症并不常见；没有灾难性出血，仅 2 例室颤组和 2 例心脏不停跳组患者需要再次探查。
随着再次心脏手术的持续增加，应采用安全且能改善手术结局的技术。作为手术替代方法，心脏不停跳二尖瓣再次右开胸手术具有体外循环时间更短、输血需求更少、术后机械通气时间更短和死亡率更低的优点。对于这种复杂的手术，这种安全有效的方法应被考虑。
