Lesão neurológica em cirurgia cardíaca: aspectos fisiopatológicos

Abstract

A lot has been said about cognitive function disorders after heart surgeries, such as myocardial revascularization, which are present causes of increased morbidity and mortality, in addition to longer hospital stay. Major advances to decrease such rates have been observed in this field, and others are still expected aiming at neurological injuries prevention.

Disfunção cognitiva após cirurgia cardíaca

“…Similarly, SAH and antihypertension therapy may be related to the cognitive outcome (Table 1), a reflection of the impaired self-regulation of the cerebral blood flow, hardening of the small cerebral arteries and generalized atherosclerotic disease existent in hypertensive individuals. Kadoi & Goto [19] Ille et al [20] Newman et al [3] Di Carlo et al [21] Ho et al [22] Roach et al [23] Wolman et al [24] Selnes et al [25] Kadoi & Goto [19] Nötzold et al [26] Intra-operative factors a) Embolization The formation of emboli, whose genesis would be the atheroma of the aortic wall, aggregated platelets, air bubbles originating from the oxygenator and the heart chambers may be the main cause of encephalic injury and the deterioration of pre-existent lesions [8]. These are subdivided in micro and macroemboli, with the former being more relevant in the emergence of CD.…”

“…There are three main causes for the genesis of microbubbles: the oxygenator itself, the cooling process of gasses which alters their solubility with predisposition to the formation of bubbles in the blood stream and the opening of heart chambers during the surgical procedure [8].…”

“…It is well known that exposure of blood to the surfaces of the CPB circuit triggers a systemic inflammatory response [40]. In areas affected by hypoperfusion, the exposure of blood to non-endothelial surfaces activates the coagulation cascade and the fibrinolytic and complement systems, as well as favoring the release of free radicals, factors that cause deterioration of preexistent lesions [8].…”

“…The main etiology of postoperative CD remains unknown, thus supporting the hypothesis that it is a multifactorial problem [1,8,10,11]. Among the involved risk factors are pre-operative (age, education, previous diseases), intra-operative (number of emboli, duration of the procedure, arterial pressure, temperature, etc.)…”

“…This is mainly due to the designs of studies (prospective or retrospective), to open heart or extracardiac surgery, the presence of comorbidities, to the method and time of evaluation of the type and degree of neurological disturbances [7][8][9]. Thus, among the most commonly studied procedures are coronary artery bypass grafting (CABG).…”