Laparoscopic autologous and heterologous ovarian transplantation in orthotopic and heterotopic location without vascular anastomosis in rabbits: morphologic and endocrinologic assessment

The purpose of this study was to assess the viability of the ovarian function and compare the success rate of autologous and heterologous ovarian transplantation in orthotopic and heterotopic location in rabbits. Eighty-nine virgin adult white New Zealand female rabbits weighing 3350–4550 g and 4–5 months old were used. The animals were randomly allocated into five groups: group Α (control group) with bilateral ovariectomy (n = 10); group Β, which underwent ovariectomy and intraperitoneal autologous heterotopic transplantation of the ovaries without vascular pedicle (n = 22); group C, in which ovariectomy was performed and autologous orthotopic transplantation in the same location without vascular anastomosis was performed, (n = 20); group D, included animals with ovariectomy and intraperitoneal heterologous heterotopic transplantation of the ovaries without vascular pedicle (n = 19); and group E, included rabbits which underwent ovariectomy and heterologous orthotopic transplantation in the same location without vascular anastomosis (n = 18). The animals were anesthetized by subcutaneous injection of xylazine (10 mg/kg) and ketamine (40 mg/kg). Once the ovaries were exposed, they were removed laparoscopically and the intact ovarian tissue was transplanted in a peritoneal pocket created in the lateral abdominal wall, or in the same location without anastomosis. In groups D and C, cyclosporine 5 mg/kg/day was administered postoperatively. Biopsies from the ovaries were taken 360 days postoperatively for histological evaluation. Blood samples for serum concentrations of FSH, LH E₂, and progesterone (PROG) were measured, on day 0 (day of surgery), day 7, day 30, day 180, and day 360 postoperatively. The histological examination showed that the percentage of functional ovaries in group B was 68.18 %, in group C was 45 %, in group D was 63.16 %, and in group E was 38.89 %. No significant difference was found between groups B and C (p = 0.129), as well as between D and E (p = 0.14). The concentration of FSH and LH in group A was significantly higher than in the other groups (p < 0.05). There was no significant difference in the level of FSH between groups B and E (p = 0.053), while comparison between groups C and E revealed statistically significant difference (p < 0.05). On the contrary, there was no significant statistical difference in the LH level between B, C, D, and E groups (p > 0.05). In group A, the concentrations of E₂ and PROG were significantly lower than the other groups (p < 0.05), while statistically significant difference was observed between B, C, D, and E groups (p < 0.05). In conclusion, autologous and heterologous ovarian transplantation of intact ovaries without vascular anastomosis was performed successfully and the animal tolerance was excellent. Orthotopic and heterotopic grafts proved to be functional by means of ovarian function and histological examination.