Effects of Portal Preconditioning In Low-Volume Liver Remnants: Study In Rats

Abstract

The increase of liver surgical indications, the expansion of the margins in hepatic resections and the lack of organ donors led to the use of more split livers from cadaver and living donors and smaller liver remnants in post-operatory patients. The use of increasingly smaller grafts associated with hepatic resections broadened the spectrum for observation of small-for size syndrome, caused by significant inflammation and early hepatic fibrosis. The small-for-size syndrome is manifested clinically by prolonged cholestasis, refractory ascites and progressive hepatic dysfunction (encephalopathy and coagulopathy). In the search for mechanisms to reduce liver damage, preconditioning is presented as a possibility of protecting the low weight remnant in experimental works. Objective: Study the hepatic tissue measuring the impact of portal preconditioning in small hepatic remnant in Wistar rats Methods: Rats weighing approximately 250g were divided in 4 groups with 7 members each. Group 1, Control group requiring only collection of the material, blood laboratory analysis and liver biopsy for pathology and immunohistochemistry; Group 2, Sham, were operated with simple laparotomy, 48 hours later they were subjected to another surgery with sample collection to do blood laboratory analysis and liver biopsy for pathology and immunohistochemistry. Group 3, hepatectomy with preconditioning. In this group was made the preconditioning procedure before the resection of 70% of the liver, 48 hours later they underwent another surgery for sample collection to do blood laboratory analysis and liver biopsy for pathology and immunohistochemistry. Group 4, hepatectomy without preconditioning. In this group the members were operated with resection of 70% of the liver, 48 hours later were reoperated with sample collection to do blood laboratory analysis and liver biopsy for pathology and immunohistochemistry. We studied and compared the impacts in morphology, laboratory, histology, immunohistochemistry.Results: There was no intraoperative mortality in the model used, there was no statistically significant difference in histological and laboratory parameters between the groups with and without preconditioning, there was an increase in the expression of PCNA with statistical significance in the hepatic remnant of the group submitted to preconditioning. Conclusion: Liver preconditioning can provide an increase in cell proliferation in small volume liver remnant.