The "Punch-Rescue" Technique: A Novel Approach To Salvage Brittle Or Torn Donor Descemet Membrane During Dmek Graft Tissue Preparation.

The preparation of DMEK grafts carries a significant risk of Descemet membrane (DM) tearing, particularly in "high-risk" donor tissue (diabetic donors or those with prior cataract surgery). Such tears often lead to tissue wastage or conversion to alternative keratoplasty techniques such as DSAEK. This presentation introduces a novel rescue technique designed to isolate and bypass peripheral DM tears during donor preparation. The goal is to minimize tissue loss, reduce surgical costs, and expand the pool of eligible DMEK donors by safely utilizing tissue that would otherwise be deemed unsuitable due to membrane brittleness or the occurrence of iatrogenic radial tears.

The technique was developed and performed at "Clinique de Montchoisi" (Swiss Medical Network), Lausanne, Switzerland. Pre-operative assessment and post-operative follow-up were conducted within the Swiss Visio network. This private surgical setting serves as a high-volume referral center for advanced lamellar corneal surgery.

During donor preparation, if a radial tear is identified, the "Punch-Rescue" technique is employed. A low-cost, sterile dermatological biopsy punch (2 mm to 3 mm) is used to create a partial circular trephination around the apex of the tear. This creates a smooth, continuous boundary that "traps" the tear, preventing further radial extension. This versatile method is compatible with any DMEK preparation technique. We demonstrate the Punch rescue maneuver on brittle donor grafts prepared with the SCUBA DMEK preparation technique where marginal tears occurring after the final 8 mm trephination were successfully bypassed, allowing a complete and controlled membrane peel.

The biopsy punch effectively arrested tear progression, salvaging donor tissue otherwise unsuitable for DMEK. By isolating the tear with a controlled, circular partial trephination, the peel was completed without further complication. While the maneuver results in a minor localized reduction in endothelial surface area, graft integrity remained sufficient for transplantation. This approach successfully salvaged tissue previously categorized as "non-DMEK eligible," reducing tissue wastage using readily available equipment. At 3 months postoperatively, clinical outcomes were validated by clear corneas, normalised pachymetry and stable graft apposition in all patients.