Effects of Er:YAG laser treatment on re-vascularization and follicle survival in frozen/thawed human ovarian cortex transplanted to immunodeficient mice

Purpose The huge loss of ovarian follicles after transplantation of frozen/thawed ovarian tissue is considered a major drawback on the efficacy of the procedure. Here we investigate whether Er:YAG laser treatment prior to xenotransplantation can improve re-vascularization and subsequently follicle survival in human ovarian tissue. Methods A total of 99 frozen/thawed human ovarian cortex pieces were included of which 72 pieces from 12 woman were transplanted to immunodeficient mice. Tissues from each woman were included in both an 8-day and an 8-week duration study and treated with either full-beam laser (L1) or fractionated laser (L2), or served as untreated controls. Vascularization of the ovarian xenografts were evaluated after 8 days by qPCR and murine Cd31 immunohistochemical analysis. Follicle densities were evaluated histologically 8 weeks after xenografting. Results Gene expression of Vegf / VEGF was upregulated after L1 treatment ( p =0.002, p= 0.07, respectively), whereas Angpt1 , Angpt2 , Tnf-α , and Il1-β were significantly downregulated. No change in gene expression was found in Cd31 / CD31 , ANGPT1 , ANGPT2 , ANGTPL4 , XBP1 , or LRG1 after any of the laser treatments. The fraction of Cd31 positive cells were significantly reduced after L1 and L2 treatment ( p