Difficulties improving ovarian functional recovery by microvascular transplantation and whole ovary vitrification

Abstract

To evaluate recovery of endocrine function and fertility after transplantation and vitrification of whole ovaries. Animal study. Lyon Veterinary School, France. Ewes. In group 1 (n = 5), the left ovary was removed with its vascular pedicle and was transplanted onto the contralateral pedicle. In group 2 (n = 5), the left ovary with its pedicle was cryopreserved after a vitrification procedure. After thawing, transplantation was performed by microvascular anastomosis to the contralateral ovarian pedicle. Median ischemia time, progesterone levels, histologic examination. Successful microsurgical transplantation was performed in both groups. The median ischemia time was statistically significantly longer in group 2 (287 minutes, range: 226 to 349] versus 129 minutes [range: 125 to 130]) in group 1. In group 1, four sheep recovered spontaneous ovarian endocrine function about 2.5 (range: 2.00 to 3.75) months after transplantation. Two ewes gave healthy live births at 12 and 25 months, respectively, after transplantation. In group 2, one ewe recovered ovarian endocrine function 6 months after transplantation. However, histologic evaluation showed a follicular survival rate of 6% in group 1, and total follicle loss in group 2. Autograft of whole sheep ovaries with microvascular anastomosis seems technically feasible but resulted in a very poor follicle survival rate (6%), in spite of endocrine function recovery and birth of two lambs. Attempts at cryopreservation with vitrification resulted in no follicle survival at all.