Whole ovary cryopreservation and transplantation: a narrative review of technological advances, biological hurdles, and clinical translation in fertility preservation.

Significant advances in cancer therapies have improved survival but often cause premature ovarian failure. While ovarian tissue cryopreservation (OTC) is an option, it suffers from ischemic damage. Whole ovary cryopreservation and transplantation (WOCT) presents a pioneering alternative. By preserving the ovary with its vascular pedicle, WOCT enables direct microvascular anastomosis during transplantation, allowing immediate blood flow. This key advantage aims to drastically reduce follicular loss and restore both fertility and long-term hormonal function through a single procedure. This review synthesizes the current state of WOCT. It outlines the structural challenges of cryopreserving a large, whole organ, critically evaluates slow freezing versus vitrification techniques, and details the surgical complexities of transplantation. Major postoperative challenges like thrombosis and follicular depletion are emphasized. The potential of adjunctive therapies (e.g., stem cells) to enhance outcomes is discussed. The review also addresses unique barriers to clinical translation, including oncological safety and the procedure's irreversibility. Finally, it explores the promise of emerging technologies like nanoparticle-assisted rewarming. The future of WOCT depends on multidisciplinary collaboration and standardized protocols to transition it from experiment to an established clinical option for restoring comprehensive ovarian function.