Percutaneous liver core biopsy in rats: an alternative to minilaparotomy

Sampling of rat hepatic tissue for histomorphological analysis is usually p erformed in two different ways: either by killing the animals or by minilap arotomy. In this study we describe a percutaneous core biopsy technique which has be en used on day 7, 14 and 21 after allogeneic rat liver transplantation (DA --> LEW) in order to examine grafts for rejection in different treatment gr oups. Fifty-two liver biopsies were performed in 24 animals using a 16-gaug e intravenous cannula. Forty-five provided usable specimens which were suff icient for both light or electron microscopy and immunohistochemical analys es to determine the degree of graft rejection. In 7 cases (13.5%) sampling was unsuccessful, especially on day 21 after transplantation, as the plasti c cannula could not penetrate the hardened tissue. In 3 animals (5.8%) punc ture was immediately followed by death due to perforation of the diaphragm or ether intoxication. In conclusion, this technique is a reliable method for providing ample tiss ue samples from the rat liver with a low risk of complications.