Experimental And Clinical Research On The Protective Effect Of Enteral Nutrition On Intestinal Mucosal Barrier Function After Liver Transplantation

Objective:Most of the recipients of orthotopic liver transplantation(OLT) often suffered from severe hepatic dysfunction and malnutrition before operations.During liver transplantation, the small intestine mucosa would experience ischemia,anoxia and intestinal injury for portal vein blocking.The oxyradical in blood, surgical stress and trauma could aggravate the injury of mucosal structure,damage of the mucosal barrier function,result in bacterial translocation.How to maintain the mucosal structure,to improve its absorption,to protect its barrier function and to reduce postoperative bacterial translocation and enterogenic infection and thus speed up the patients'recovery,these were of much significance to patients who were in immunosuppression after OLT.This experimental and clinical research aimed at analyzing the protective effect of different nutritional therapies on intestinal mucosal barrier function after OLT, and investigating the optimal time of enteral nutrition (EN)after OLT and providing scientific evidence for reduce the enterogenic infection.Methods:1. Experimental research:A model of OLT in rats was established.Except normal control and liver transplantation control,54 rats were randomizedly divided into three groups according to the different nutritional therapies:group A (total parenteral nutrition group), group B (enteral nutrition from the 24th post-OLT hour group), group C (enteral nutrition from the 72th post-OLT hour group). Group A were given all-in-one nutrient fluid from the 6th post-OLT hour and maintained for 7 days.the other two groups were given enteral nutrition from the 24th or 72th post-OLT hour, the two EN groups were given TPN before given EN.The specimen of blood were obtained on 1st,3rd and 7th day and the specimen of intestine was collected on 7th day after surgery, detected the portal vein blood endotoxin by kinetic turbidimetric assay and the plasma D-lactate level by enzyme-linked ultraviolet spectrophotometry. In addition,morphology changes of intestine were analyzed.2. Clinical research:Thirty OLT recipients between January 2006 and December 2006 in Institute of Hepatobiliary Surgery,Southwest Hospital, The Third Military Medical University were randomizedly classified into three groups according to the different nutritional therapies: group A (total parenteral nutrition group), group B (enteral nutrition from the 24th post-OLT hour group), group C (enteral nutrition from the 72th post-OLT hour group).Group A were given all-in-one nutrient fluid from the 6th post-OLT hour and maintained for 7 days.the other two groups were given enteral nutrition from the 24th or 72th post-OLT hour.The specimen of blood were obtained at different time points, compared the three groups with the plasma endotoxin and D-lactate level, recovery times of gastrointestinal function, the incidence of gastrointestinal complication, the time length of ICU, the length of hospitalization after surgery, the liver zymogram.Results:1. experimental researchCompared with normal control ,the portal vein blood endotoxin and D-lactate level were significantly higher in 6th post-OLT hour .In addition, the endotoxin and D-lactate level in group B decreased significantly compared with that in group A on 3rd and 7th day after surgery, P <0.05. There were no statistical difference between normal control and group B on 7th day, P>0.05. There were no statistical difference in endotoxin and D-lactate level between group A and C on 3rd day, P>0.05. The endotoxin and D-lactate level in group B, C were lower than group A on 7th day after OLT.On 7th day after OLT,in group A,intestinal mucosa was thin and mucosa atrophy occured,villus was short,some of the villus were absent. In group B, intestinal mucosa was normal, there was no defects in chorioepithelium. In group C, there was water thesaurismosis lightly in villus.The changes of ultramicrostructure of the small intestine mucosa in group A were that microvilli were rare and in disorder, mitochondrial cristaes break and dissolve.The group B was normal in the ultramicrostructure.There was a little raritas of the microvilli in the group C.2. clinical researchThe plasma endotoxin and D-lactate level of the three groups on 1st day after OLT were significantly higher than those before.The D-lactate level in group B decreased significantly compared with the other two groups on 3rd day,the endotoxin was lower than group A, P <0.05.And there were no statistical difference in endotoxin and D-lactate level between group A and C on 3rd day, P>0.05. The endotoxin and D-lactate level in the group B, C were lower than the group A on 7th day after OLT, P>0.05.Recovery times of gastrointestinal function , the time length of ICU in the group B were significantly shorter than the other two groups,P<0.05.There were no statistical difference in the incidence of gastrointestinal complication and the liver function in the three groups,P>0.05.Conclusions:1. The intestinal permeability increased in these recipients of liver transplantation,indicating intestinal mucosal barrier dysfunction.2. Enteral nutrition from 24th post-OLT hour could protect intestinal mucosal barrier function, maintain the mucosal structure.3. Enteral nutrition for patients from the 24th post-OLT hour could promote recovery of gastrointestinal function and shorten the time length of ICU stay. It may not increase the incidence of postoperative gastrointestinal complication and the damage of liver function.