腹主动脉阻断术临床原理及其上中下段安全时限探讨——兼述缺血再灌注损伤机制与对策及“二叉树耐受法则”

目的深入探讨腹主动脉阻断术的临床原理及其高中低位阻断安全时限等问题,以期在临床上安全地使用该技术。方法1980年-1982年我们首次进行了腹主动脉阻断安全时限及其阻断与撤钳后病理生理变化的前瞻性实验研究。结果表明:犬腹主动脉阻断25min为安全时限;在阻断安全时限内,犬体内血液动力学、血气酸碱、血液生化和主要的脏器超微结构(脑肺肝肾胰肠脊髓)仅发生轻度可逆性改变;如超出安全时限,上述指标则会发生难以代偿的严重改变。基于广义生命时空场论学说,通过对腹主动脉阻断术解剖学基础,腹主动脉阻断后与撤钳后综合征群(呼吸宭迫综合征、急性高血压性脑水肿、多脏器微栓塞病细胞综合征、撤钳后中枢性呼吸衰竭)及腹主动脉阻断所致的缺血再灌注损伤病理生理与细胞分子生物学机制等讨论,并根据近期实验与临床研究结果和结合文献复习对相关问题做了探讨,对临床上预防和治疗腹主动脉阻断术所致的缺血再灌注损伤提出了一整套对策。此外还叙述了预防腹主动脉阻断术并发症的远端主动脉灌注、脑脊液引流以及硬膜外冷却、控制性再灌注与缺血预/后处理等几种新技术。结果如果超出腹主动脉阻断术安全时限,则在术中与术后将发生缺血再灌注损伤、全身炎症反应综合征和多脏器衰竭。临床上,人类一次性持续腹主动脉阻断术安全时限如下:高位(T12水平,腹腔干A上)、中位(L2水平,肾A上)与低位(L4水平,髂总A上)均不能轻易超越25-30min。如术中须延时宁可采用间断阻断法。结论如果"二叉树耐受法则"(即体内任何一处大血管阻断均不能超出其固有安全时限,否则受术者非死必伤)被严格遵守,则腹主动脉阻断术中与术后病人的安全将得到保证。

Clinical principal and safe time limit of various level of abdominal aorta clamping-The role of bintree tolerance law in preventing ischemic reperfusion injury

Objective In order to guarantee the safety of abdominal aorta clamping,the clinical principle and the safe time limit of various level of AAC were investigated in this study.Methods During 1980-1982,we had carried out a series of studies in the safe time limit and the pathophysiological changes of abdominal aorta clamping(AAC) for the first time.Our results showed that 25 min is the safe time limit of abdominal aorta clamping in dogs in vivo.There are only small and reversible changes in hemodynamics(Heart Rate/HR,Blood pressure/BP,Central venous pressure/CVP,Total peripheral resistance /TPR,Cardiac output/CO,Right carotid and femoral arterial flow/RCF and RFF) and acid-base equilibrium(PH,HCO-3 BEP,BBP),blood biochemisty(Seroenzymes-SGPT,SGOT,AKP and LDH;Plasma protein-Total protein,Albumin and Globulin;Electrolytes-K ,Na ,Cl-,Ca2 and P-;Blood sugar,Amylase,NPN;Coagulation state - Prothrombin,Platelet,Fibrinogen) and in the ultrastructures of various organs(cerebral,pulmonary,hepatic,Kinney,pancreatic,intestine and spinal cord).When the clamping exceeds its safe time limit,it is highly likely that it will induce severe changes,which may be irreversible and difficult to compensate.Based on the theory of General life time space field(GLTSF),we investigated the anatomical principle of AAC,the syndromes during AAC including respiratory distress syndrome(RDS),acute hypertensive cerebral edema(AHCE),multiple organs microthombosis - sicked cells syndrome(MOMSCS) and the syndrome of central respiratory failure(CRF) after declamping ;and the mechanisms of pathophysiological and cellular molecular biology of ischemic reperfusion injury caused by AAC.Recent animal studies and clinical applications as well as literature review in the field were also discussed.A set of clinical strategy was proposed for prevention and treatment of ischemic reperfusion injury(IRI) of AAC.Furthermore,new techniques such as distal aorta perfusion(DAP),cerebrospinal fluid drainage(CSFD),and epidural cooling(EC) for preventing the complications after AAC were evaluated in this paper.Results During and after abdominal aorta clamping,if the procedure exceeds the safe time limit,ischemic reperfusion injury(IRI)will occur,followed by systemic inflammatory response syndrome(SIRS) and multiple organ failure(MOF).The safe time limits in various level of AAC including high level(T12 level,above celiac trunk artery),medium level(L2 level,above renal artery) and low level(L4 level,above common iliac artery) are between 25 to 30min.Conclusion The clinical safety of patients will not be compromised if the bintree tolerance law/BTL is strictly followed during abdominal aorta clamping.