The Clinical Study Of The Effect Of Serum Cytokines On Beating Heart Surgery During Normothermic Cardiopulmonary Bypass

With the improvement of operation and CPB technology,intracardiac operation under direct vision to cure heart disease is muchsafer than before. But CPB is not perfect enough to meet the needs ofthe organism. Since the wide use of the technology, the side effect ledby CPB has arouse people's attention. That CPB leadscardiopulmonary bypass-induced systemic inflammatory response(SIRS) is the new concept proposed by Kirklind in early 1980s andhas caused the extensive concern both at home and abroad. At present,it is generally believed that many stimuli during CPB may leadinflammatory responses. Once extra circulation is constructed duringintracardiac operation, organism is hurt at least 3 aspects: 1)nonphysical infusion causes ischemic and reperfusion injury; 2)Foreign substances such as circulate pipage contact with blood, andheparine-protamine complex evoke complement system activation; 3)interal organ barrier function weaken, endotoxin released, inducedcomplement activation,cytokine released,leukoyte stimulatetd anddelivering products,endothelin,nitrogen monoxidum,arachidonicacid metabolic product as well as platelet activating factor and so on.These changes have intimate relationship to MODS.These inflammatory mediators have constructed very complexnetwork and the widespread inflammation,and SIRS occure. Theserious SIRS are the pathologic foundations of a series ofpostoperative complications, such as low cardiac output syndrome,respiratory failure, renal and neurologic dysfunction, bleedingdisorders, altered liver function, and ultimately, multiple organ failure(MOF). Therefore, how to prevent and treat CPB induced SIRS hasbeen the focus of research both at home and abroad. In the processcytokines are the important mediators in response to CPB inducedSIRS and indicate the extent of the SIRS, so they can be viewed as theimportant indexes to CPB induced SIRS. The rise and development ofSIRS is a complex sequence of acute phase reaction. The severity ofSIRS is mainly determined by the balance between thepro-inflammatory cytokines (TNF-α, IL-6, IL-8), the role of theanti-inflammatory cytokine (IL-10). When the pro-inflammatorycytokines appear in the organism, the anti-inflammatory cytokines willarise at the same time to prevent pro-inflammatory cytokines and theinjuries of mediators. This is defined as compensatoryanti-inflammatory response syndrome (CARS). The balance betweencytokines stabilizes the organic system while the unbalance, that is,SIRS is out of control or extreme CARS arises, will cause thedamages of the tissues and organs. Thus, to study and investigate therelease of various cytokines and their changing principles as well asmake clear of the mechanism and factors that influence their changeshas become hottest research in the basic heart surgery field. This studyfocuses on the effect of CPB in warm heart surgery on serumcytokines, in terms of CPB induced SIRS and the changing ofcytokines. By far the traditional hypothermic CPB is widely used in clinic.This method adopts mild hypothermia for the whole body, deephypothermia for some part of heart, cross-clamps the ascending aorta,and perfuses the cold stopping-pulse solution. There are quite a fewreports on the effect of hypothermic CPB on cytokines. In thehypothermia CPB, ischemia and reperfusion, the activation ofcomplement systems, the release of endotoxin and other cytokinesmay contribute to the release of cytokines. Numbers of researcheshave proved that in the process of hypothermic CPB the levels ofcytokines TNF-α, IL-6, IL-8 are rising and the density of thesecytokines is related to the time of myocardial ischemia during CPB. Inthe hypothermic CPB hypothermia and aortic cross-clamping changethe micro-structure of the heart and lead to the pathophysiologicchange. Hypothermia brings in many side effects to the organismwhile aortic cross-clamping causes myocardial ischemia, meageroxygen injury and reperfusion injury. Therefore, in recent yearscardiac surgeons were searching all the way the better way to alleviatethe organic injury caused by hypothermic CPB. By the end of the1980s, Canadian expert Lichtenstein first proposed the new concept"Warm heart surgery", which brings about wide concern andexploration. Almost in the same period, the warm beating heartsurgery has developed gradually both at home and abroad and afterseveral years development and improvement, intracardiac operationunder direct vision with beating heart has become more systemic,more extensive and more routinized so much so that it enlightens arevolution in the intracardiac operation under direct vision and it hasobtained a relatively satisfactory clinical result, admitted by more andmore cardiac surgeons. The characteristic of the operation is thatduring the extracorporeal circulation no temperature reduction of bodyor aortic clamping occur, so the heart is supplied, by heart lungmachine, with blood from the normal coronary artery like other organsand the cardiac muscles are supplied with constant oxygen andnutrition so that the heart is in the status of aerobic metabolism, acidbase equilibrium, and electrolyte metabolism closest to itsphysiological one. Therefore, in the operation we will maintain sinusrhythm and unloading pump of heart with the normal heart circulation;beating heart surgery can avoid and eliminate myocardial ischemia,meager oxygen injury and reperfusion injury caused by aorticcross-clamping in arrested heart surgery; normothermia has littlestimuli toward organism so that it can avoid the side effect of thetemperature reduction, reduce the organic disorder and provide acloser physiological environment for the patient; In this surgery sincethe process of heart arrested and heart rebeating is eliminated, theoperative procedure is simplified and the operating time as well astime for extracorporeal circulation has been largely reduced. Therefore,seldom or never do the patients develop such complications asmyocardial dysfunction, severe cardiac arrhythmias or acute renalfailure after operation. Compared with any arrested heart surgery, thismethod shows greater benefits in reducing the injuries on organism. Normothermic CPB as a simple, effective method has beenrecognized gradually by people and widely put into use. However, thestudy reports on its pathophysiologic aspect are rather few and there isno report on its effect on cytokines at home. This experiment isintended to study and explore the influence of normothermic beatingheart surgery on CPB induced SIRS. We will observe and compare thereleasing rules of cytokines TNF-α, IL-6, IL-8 and IL-10 in patients'serum in both normothermic beating heart group and hypothermicarrested heart group. The purpose of the experiment is to evaluate theeffect of normothermic CPB with beating heart on SIRS and analyzeits clinic significance. The objectives in the study are the patients with congenital heartdisease in our department. They are divided into observation groupand control group randomly. There were 15 patients in every group.The observation group received surgery on beating heart withnormothermia and control group received operation on arrested heartwith moderate hypothermia CPB. We use the method of ELISA todetermine the level of TNF-α,IL-6,IL-8,IL-10 before CPB,...