Liver Regeneration After Percutaneous Ethanol Injection Into Liver Under Ultrasonographic Guidance

Objective:The aim of this paper is to study the liver of SD rats regeneration recovery and its characteristics after percutaneous ethanol injection(PEI) into the liver under ultrasonographic guidance.To explore the feasibility of PEI in animal experiments and provide experimental evidence for interventional treatment and diagnosis of liver and other organs'diseases.Methods:During preoperation, 40 rats undergo intraperitoneal injection of 1% pentobarbital. Intruments for PEI consisted of a 1-mL syringe ,4 1/2 needle .PEI was performed using IU22 with a 5-12MHZ probe. Absolute ethanol was slowly injected from the 1-mL syringe through the needle under ultrasonographic guidance. The amount of injected ethanol into the middle lobe of the rats was usually 0.1ml per rat. Before surgery and after 1,3,5,7,days later, were measured serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels to observe liver function. Excising liver was performed immediately after collecting blood, silicing the normal liver tissue which surrounded the ethanol injection site, stripping the liver capsule and intrahepatic connective tissue,washing by 0.01M phosphate buffer(PBS),cutting into pieces,then digesting with collagenase to become single cell suspension and fixed it with 80% ethanol. After fixed, then washing twice by PBS,adding iodine-c tablets(PI) and 0.1% RNA enzyme(RnaseA) determine S-phase cell ratio(SPR) via flow cytometry (S-phase cell/total cell number). The other normal liver tissue surrounded ethanol injection site were placed in 10% formalin to fix,dehydrate and made into paraffin.The mitotic index(MI)of the liver was examined by HE staining. The contents of DNA in cell nuclear was detected by Feulgen staining and use immunohistochemistry technology to detect proliferation cell nuclear antigen(PCNA).Results: 1 to 3days after the PEI,the liver tissue MI, the contents of DNA in cell nuclear and PCNA,SPR higher than the normal (P<0.01),and at the 3 days after PEI, the liver regeneration was at the peak。MI:(1.76±0.20)%,SPR:(16.53±2.96)%; the contents of DNA in cell nuclear(:8.68±0.94)%;PCNA(:11.08±1.65)%,5 days later, the regeneration obviously decreased. The liver function increased most at the first day after PEI. AST: (417.02±25.07)U/L,ALT(:357.93±26.83)U/L respectively, and then to decline until the seventh days can recover the normal.Conclusions: Dehydration and coagulation are the characteristics of absolute ethanol, which can make blood vessel embolize and can directly lead to complete cogulation necrosis in liver tissue. The local diffusion and high concentration of the ethanol induced by PEI caused the liver cell death, which could enhance the liver regeneration. The regeneration and recovery characteristic maybe useful in the clinic. Ultrasound—guided PEI have many advantages such as minimal trarma, reproduction, effectiveness,less side effects, rapid recovery, easily accepted by patients. All of these advantages made PEI widely applied in the future.