Laparoscopic transplantation of metanephroi: A first step to kidney xenotransplantation

Abstract

Background: Embryonic kidney xenotransplantation could represent a new solution to the scarcity of kidneys for transplantation.

Objective: To determine the feasibility of allogeneic laparoscopic transplantation of metanephroi (M) in rabbits.

Material and method: Microscopic dissection was conducted to obtain metanephroi from 14-day-old (24M), 15-day-old (20M) and 16-day-old (26M) embryos. Using single-port abdominal laparoscopy, a spinal needle was inserted percutaneously, through which the metanephroi were deposited (using an epidural catheter) close to a patent blood vessel in the retroperitoneal fat. Seventy metanephroi were transplanted to 18 rabbits. Three weeks later, the animals were examined through open surgery. We compared the embryonic maturity, the morphometric variables of the metanephroi and the development rate of the transplanted metanephroi.

Results: The lower time limit for the extraction of metanephroi from the rabbits was day 14. Three weeks after transplantation, only 3/24 14-day-old metanephroi grew at minimal expression (12.5%). In contrast, 10/20 (50%) 15-day-old and 12/26 (46.1%) 16-day-old metanephroi grew. These metanephroi had differentiated sufficiently for the glomeruli, proximal and distal tubules and collecting ducts to develop normally. We detected no relevant immunological changes in the peripheral blood.

Conclusions: We have described for the first time in the literature the allogeneic laparoscopic transplantation of metanephroi from embryos as a feasible and noninvasive technique. The recipients did not require immunosuppression.

Keywords: Immunosuppression; Inmunosupresión; Kidney transplantation; Laparoscopia; Laparoscopy; Trasplante renal; Xenotransplantation; Xenotrasplantes.