美科学家认为旁路手术不会影响大脑功能

关于冠状动脉旁路手术对记忆以及其他大脑功能影响的回顾性研究显示：尽管手术可能具有暂时的短期效应，该手术可能不会导致后期的或者持久的神经系统缺陷。

研究人员发现：在某些长期研究中观察到的后期认知下降可能与原有疾病的进展有关，例如脑血管疾病，而不是手术本身的作用。而例外情况包括老年患者和那些具有脑血管疾病风险的患者或者出现过脑卒中发作史的患者。

令人感兴趣的研究证实：在手术之后3个月的时间内出现轻微病变，这是由于血流轻度紊乱或者其他手术相关因素造成的，诸如炎症或者麻醉。当研究人员检查最权威试验研究的时候，他们在大多数患者3个月之后，没有发现支持认知缺陷的强有力证据。

Johns Hopkins医院神经病学教授Ola Seines博士说：“我们考虑在某些亚群患者冠状动脉旁路移植手术之后，存在短期认知缺陷，但是没有明显的脑卒中发作，而这些病变通常是轻微暂时的。”

作者说，研究中发现的认知功能缺陷一个可能原因，是接受旁路手术的人群变得更加衰老与虚弱，患高血压、糖尿病、先兆脑卒中以及其他疾病的机会更多。

Seines博士说：“我们相信接受冠状动脉旁路移植手术的患者，不应当为后期可能出现的认知功能缺陷而感到沮丧。”
 
Bypass Surgery May Not Affect Brain Function
 
A broad retrospective review of the effects of coronary bypass surgery on memory and other brain functions has shown that while there may be transient short-term effects, the procedure probably does not cause late or permanent neurologic defects.

The researchers found that the late cognitive declines seen in some long-term studies are likely associated with the progression of underlying conditions, such as cerebrovascular disease, rather than the surgery itself. The exceptions might include older patients and those with risk factors for cerebrovascular disease or a history of stroke.

Existing studies confirm the existence of mild deficits in the period up to three months after surgery, which may be due to minor disruption in blood flow or other surgery-related factors, such as inflammation or anesthesia. When the researchers examined the most authoritative studies, they failed to find strong evidence that cognitive deficits persist after three months in most patients.

“We think that there are short-term cognitive changes after coronary artery bypass grafting (CABG) in a subset of patients, but absent a frank stroke, these changes are generally mild and transient,” said author Ola Seines, Ph.D., professor of neurology at Johns Hopkins Hospital (Baltimore, MD, USA).

One possible cause of the cognitive defects found in studies, say the authors, may be the fact that the population having bypass surgery is becoming older and sicker, with more hypertension, diabetes, previous strokes, and other disorders.

“We believe that patients should not be discouraged from having CABG because of the risk of late cognitive function,” added Dr. Seines.