Kidney transplantation in rats: an appraisal of surgical techniques and outcome.

Renal transplantation in rats is an essential experimental tool in transplantation research. The surgical procedure per se could affect the outcome of an experiment, independent of the hypothesis addressed, therefore requiring a standardized method which should be comparable across studies. To date, however, there is little information on the optimal surgical technique. We performed a Medline search on original articles published between 1965-2001 in order to evaluate whether specific technical issues affecting the outcome of the procedure could be defined. Articles that reported on a novel microsurgical procedure, or whose main purpose was the outcome of a surgical technique itself, were included in the analysis. From 2,060 retrieved publications, 34 corresponded to the selection criteria (rats and microsurgery and technique and kidney or renal transplantation). Among the essential determining factors for a good outcome, body weight >200 g and warm ischemic time <30 min were identified. Other important factors were the techniques used for vascular (end-to-end and end-to-side procedure or sleeve technique) and ureteral (bladder patch or end-to-end procedure) anastomosis. Gender, animal strain, type of anesthesia, prophylactic administration of antibiotics, and type of flushing solution did not affect the success of renal allografts. In order to avoid a bias related to the surgical procedure in rat renal transplantation, a warm ischemia time <30 min in animals with a body weight >200 g seems to be essential. Also, end-to-end or end-to-side vascular anastomoses are preferable to the sleeve technique. Other factors do not influence the immediate function of the graft.