Zero warm ischemia time in whole-eye transplantation through retrograde extracorporeal perfusion

PurposeTo develop and demonstrate the anatomical feasibility of a human whole-eye transplantation (WET) protocol that eliminates warm ischemia time (WIT) through continuous retrograde arterial perfusion, enabling uninterrupted ocular oxygenation throughout the transplantation process. DesignExperimental cadaveric feasibility study. SubjectsTwo fresh human cadaveric specimens used to simulate a complete donor-to-recipient WET sequence. MethodsA modified fronto-temporo-orbito-zygomatic craniotomy with anterior clinoidectomy was performed on each donor to expose the anterior cerebral artery (ACA), middle cerebral artery (MCA), and ophthalmic artery (OA). The ACA was cannulated to permit continuous retrograde perfusion of the ophthalmic circulation while the globe, with preserved optic nerve and extraocular muscles, was harvested en bloc. Recipient preparation involved mobilization of the internal maxillary artery (IMAX) in the infratemporal fossa and removal of the native globe. Orthotopic transplantation was achieved with MCA-IMAX and superior ophthalmic vein (SOV- SOV) microvascular anastomoses and optic nerve coaptation under microscopy, maintaining continuous simulated perfusion through the ACA cannula. Main Outcome MeasuresAnatomical feasibility of achieving zero warm ischemia time during the entire transplantation sequence, confirmed by optical coherence tomography (OCT), intraoperative microscopy, and photographic documentation of vascular and neural integration. ResultsContinuous retrograde perfusion was maintained throughout donor harvest and transplantation, achieving zero WIT across both specimens. OCT verified luminal patency and vessel continuity after ACA cannulation and MCA-IMAX anastomosis. The IMAX provided a robust, tension-free arterial recipient site with consistent caliber and orientation. Optic nerve coaptation and extraocular muscle reattachment were anatomically aligned, with sequential imaging confirming vascular and neural integration. The technique proved reproducible across both dissections, supporting its feasibility for perfused, anatomically integrated ocular allotransplantation. ConclusionsThis study establishes a reproducible human WET protocol achieving zero WIT via continuous retrograde extracorporeal perfusion. The approach provides a foundational anatomical framework for future functional and preclinical studies aiming to preserve retinal viability and enable neurovascularly integrated whole-eye transplantation.