A Comprehensive Review of Advances in Ovarian Tissue Transplantation: From Cryopreservation Protocols to Graft Revascularization Dynamics

Ovarian tissue cryopreservation and transplantation represent promising strategies for fertility preservation in domestic species, laboratory models, and wildlife. However, follicular survival after transplantation remains limited by ischemia–reperfusion injury, delayed revascularization, and microenvironmental disruption. Thus, this review provides an update on cryopreservation methods, grafting approaches, angiogenic modulation, and microscopical tools used to evaluate ovarian tissue viability. Evidence indicates that follicular outcomes are influenced by the type of cryopreservation technique, ischemic duration, grafting site, and factors governing angiogenesis and extracellular matrix remodeling. Pro-angiogenic molecules, antiapoptotic agents, mesenchymal stem cell co-transplantation, and emerging biomaterials have shown potential to enhance vascular perfusion and reduce follicular loss. Histological and histochemical techniques, including PAS and Picrosirius Red staining, remain essential for assessing follicular morphology, stromal integrity, and collagen organization. In addition, immunostaining facilitates the investigation of key biological processes, including angiogenesis, cell death, and cellular proliferation. Collectively, these findings highlight that refining cryopreservation methodologies, improving revascularization, and adopting standardized morphological evaluation are crucial steps toward increasing the efficiency of ovarian tissue transplantation in livestock species. Continued integration of reproductive biotechnology, tissue engineering, and molecular analyses is expected to expand the applicability of this technique in animal reproduction, production systems, and biodiversity conservation.