Heterotopic ovarian transplantation without vascular pedicle in syngeneic Lewis rats:: long-term evaluation of effects on ovarian structure and function

Objective: To assess the long-term efficacy of intraperitoneal (IP) and subcutaneous (SC) ovarian autotransplantation in rats. Design: Experimental animal study. Setting: Unit of Experimental Research, Barcelona University School of Medicine. Animal(s): Female syngeneic Lewis rats aged 14 weeks. Intervention(s): Group A, control group undergoing ovariectomy (n = 15): group B, undergoing ovariectomy and IP autologous heterotopic transplant (n = 15), and group C, ovariectomized with SC autologous heterotopic transplant (n = 15). In groups B and C, live animals were killed and their ovaries removed for morphometric analysis at 30 days after transplantation; five additional animals were killed at 180 days, and the remaining five animals were killed at 360 days. Main Outcome Measure(s): Ovarian morphometric analysis and serial measurement of E-2 and FSH serum levels. Result(s): The mean number of antral follicles in the control group A was significantly higher than that observed in the ovarian grafts collected and examined 30 days after grafting in rats from groups B and C, but the mean granulosa cell area was significantly higher in both transplantation groups than in controls because of ovarian follicular hyperplasia. Histological examination of ovaries removed at 6 and 12 months after grafting in groups B and C showed increasing degrees of fibrosis, loss of primordial follicles, and the presence of epithelial cysts. In groups B and C, from day 30 after surgery onward, serum E-2 was significantly higher and FSH significantly lower, respectively, than in group A. E-2 and FSH patterns in groups B and C were similar throughout the study period. Conclusion(s): Heterotopic ovarian transplantation without vascular pedicle in rats is characterized by follicular hyperplasia endocrinologically functional, followed by progressive loss of follicles in heterotopic ovarian autografts. (Fertil Steril(R) 2002;77:396-402. (C)2002 by American Society for Reproductive Medicine.).