Development Of The Quantitative Hepatic Portal Blood Flow Limiter As Well As Application Research In Liver Resection

Objective: To investigate an optimum proportion of blood flow limitingduring the liver resection surgery so as to decrease hepatic dysfunction andsystemic adverse effects followed by hepatic blood flow restriction on the basis ofreducing intraoperative blood loss, as well as to improve the survival andprognosis.Method:1.To design the quantitative hepatic portal blood flow limitingdevice according to hilar anatomical structure and blood flow characteristics,which will be certified by the authority, and then produced and used onexperimental animal model;2. In the rabbit model, to research hepatic perfusionsunder different limiting proportions by the quantitative hepatic portal blood flowlimiter;3. Achieving parameters of intraoperative blood loss, liver functionchanges during6h,3d and7d after liver resection, and seven days survival ratefollowed by establising a hepatectomy of left and middle lobe in the rabbit modelwith blocked the hepatic artery as well as varied the limiting proportions of portalvein, and then to discuss an optimum proportion of portal flow limiting.Results:1.The quantitative hepatic portal blood flow limiter has beencerticatied by the State Intellectual Property Office of the People’s Republic ofChina and has been granted Utility Models.2. In a rabbit model with closedhepatic artery and restricted portal vein, correlation between portal vein flowvolume and hepatic perfusion is positive linear. Meanwhile, hepatic vein also playa role in sustaining hepatic perfusion, contributed proporation of which may be29.6%. Acquired linear regression equations:①P(Pu)=85.825+2.051V(ml/min);②P (Pu%)=0.296+0.662V(ml min-1%)(p<0.01).3. In a rabbit hepatectomy (leftlobe, middle lobe) model with hepatic arterial blood flow(HAF) completelyblocked, when portal vein flow had been restricted in the ratio of100%,90%,80%,70%and0%for45min, the7d-survival rates would be0%,10%,60%,80%and100%.4. In a similar model as the one above but with PVF restricted for30min, we found (1) there are no significant differences between PVF restrictionratio of80%and completely blocking PVF in the field of intraoperative blood loss; (2)By analysis of postoperative liver pathology and serum liver enzymatic level,we detected degree hepatic injuries. Recovery time might be a major factorregardless of PVF restriction ratio: hepatic cell injury peaked at6h after operationand then gradually restored. There were no significant differences betweenrestriction of0%and70%(p>0.05), but significant in groups over80%(p<0.05).However, no significant differences exist between70%and80%.(p>0.05)(3)Intestinal mucosa necrosis caused by limiting PVF peaked at6h after liverresection, especially when restriction ratio over80%. Since3days after surgery,intestinal mucosa had been gradually recoverd. Differences between each groupexpressed vague.(4)Recovery time was a major factor in hepatocyte regeneration.There were no significant differences between0%and80%(p>0.05), butsignificant in the groups over80%(p<0.05). However, no significant differencesexist between80%and90%(p>0.05).Conclusion: The developed quantitative hepatic portal blood flow limitercould be well used in hepatectomy, but still to be improved. In hepatectomy modelwith HAF completely blocked, we found that PVF is a protective factor forsurvival, while restriction ratio of which is above80%. Meanwhile, PVF ispositive linear correlated with liver perfusion pressure. The threshold of PVFrestrition proportion might be exist, blood loss of which could be within the rangeof70%-90%, while IRI of which could be within the range of80%-90%, andliver regeneration70%-80%.