Knipp Stephan C, Matatko Nadine, Wilhelm Hans, Schlamann Marc, Massoudy Parwis, Forsting Michael, Diener Hans Christian, Jakob Heinz
Department of Thoracic and Cardiovascular Surgery, University Hospital, Essen, Germany.
Eur J Cardiothorac Surg. 2004 May;25(5):791-800. doi: 10.1016/j.ejcts.2004.02.012.
Neurocognitive dysfunction is a common complication after cardiac surgery with cardiopulmonary bypass (CPB). Studies using magnetic resonance imaging (MRI) have demonstrated that new focal brain lesions can occur after coronary artery bypass grafting (CABG), even in patients without apparent neurological deficits. Diffusion-weighted MRI is superior to conventional MRI and allows for sensitive and early detection of ischemic brain lesions. We prospectively investigated cerebral injury early and 3 months after CABG using diffusion-weighted MRI and related the findings to clinical data and neurocognitive functions.
Twenty-nine patients [67.6+/-8.6 (52-85) years, 5 females] undergoing elective CABG with CPB were examined before surgery, at discharge and 3 months after surgery. A battery of standardized neuropsychological tests and questionnaires on depression and mood were administered. Conventional and diffusion-weighted MRI of the brain was performed and new lesions were analyzed. Clinical characteristics, neuropsychological test performance and radiographic data were collected and compared.
There was no major neurological complication after CABG. Thirteen patients (45%) exhibited 32 new ischemic lesions on postoperative diffusion-weighted MRI. The lesions were small, rounded and equally dispersed in both hemispheres. Eight patients had at least two lesions. At discharge, significant deterioration of neuropsychological performance was observed in 6 of the 13 tests compared to baseline assessment. By 3 months postoperatively, 5 of the 6 tests returned to preoperative levels. Verbal learning ability, however, remained impaired. The presence of new focal brain lesions was not associated with impaired neuropsychological performance. There was also no correlation between clinical variables, intraoperative parameters and postoperative complications and MRI findings.
Although neurocognitive decline after CABG is mostly transient, memory impairment can persist for months. New ischemic brain lesions on postoperative diffusion-weighted MRI do not appear to account for the persistent neurocognitive decline.
神经认知功能障碍是体外循环心脏手术后常见的并发症。使用磁共振成像（MRI）的研究表明，冠状动脉旁路移植术（CABG）后即使在没有明显神经功能缺损的患者中也会出现新的局灶性脑损伤。扩散加权MRI优于传统MRI，能够敏感且早期检测出缺血性脑损伤。我们使用扩散加权MRI对CABG术后早期及3个月时的脑损伤进行前瞻性研究，并将结果与临床数据和神经认知功能相关联。
29例接受择期体外循环CABG手术的患者[年龄67.6±8.6（52 - 85）岁，5例女性]在手术前、出院时及术后3个月接受检查。进行了一系列标准化神经心理测试以及关于抑郁和情绪的问卷调查。对脑部进行传统和扩散加权MRI检查并分析新出现的病变。收集并比较临床特征、神经心理测试结果和影像学数据。
CABG术后未发生重大神经并发症。13例患者（45%）在术后扩散加权MRI上出现32个新的缺血性病变。病变较小，呈圆形，在双侧半球均匀分布。8例患者至少有两个病变。出院时，与基线评估相比，13项测试中有6项神经心理表现显著恶化。术后3个月时，6项测试中有5项恢复到术前水平。然而，言语学习能力仍受损。新的局灶性脑损伤的存在与神经心理表现受损无关。临床变量、术中参数、术后并发症与MRI结果之间也无相关性。
尽管CABG术后神经认知功能下降大多是短暂的，但记忆障碍可能持续数月。术后扩散加权MRI上新出现的缺血性脑损伤似乎不能解释持续的神经认知功能下降。
