Uterus transplantation in a non-human primate: long-term follow-up after autologous transplantation

Uterus transplantation (UTx) may provide the first available treatment for women affected by uterine infertility. The present study aimed to further develop a surgical technique for autologous UTx in a non-human primate species and to assess long-term function.

Female baboons (n= 16) underwent autologous transplantation of the uterus with the Fallopian tubes and ovaries, performed with a previously published surgical technique (n= 6, Group 1) or using a modified technique (n= 10; Group 2). The uterine arteries were dissected to the proximal end of the anterior branch (Group 1) or the entire (Group 2) internal iliac artery, and the ovarian veins were dissected to the crossing over the ureter (Group 1) or further cranially to include greater lengths and patches of the cava/renal vein (Group 2). Back-table preparation created common venous and arterial ends with arterial anastomosis either end-to-side to the left external iliac artery (Group 1) or end-to-end to the left internal iliac artery (Group 2).

Overall short-time survival of the animals was 88% (66% in Group 1 and 100% in Group 2). Of all the operated animals, 75% (66% in Group 1 and 80% in Group 2) resumed ovarian cyclicity. Regular menstruation after UTx was demonstrated only in Group 2 (60%). Menstruating animals (n= 6) were each exposed to timed mating for ≥5 menstrual cycles, but pregnancy did not occur. Adhesions and tubal blockage were seen in post-mortem analysis.

The modified UTx model of Group 2 is a safe procedure and shows resumed long-term uterine function in a majority of the animals, although pregnancy could not be demonstrated.