Anatomy, evolution and clinical aspects of the superextended-intercompartimental-supraretinacular artery perforator flap (SISAP-flap): a proof of concept

Background Extended soft tissue defects of the fingers -nevertheless its origin- are challenging to treat. When amputates are missing or crush injuries are present, there are often only limited options other than further amputation, ray resection, or free tissue transplantation. The SISAP-flap is developed to add an extra option of treating finger avulsion injuries or otherwise extended soft tissue finger defects. Methods Cadaveric SISAP-flaps were individually dissected, tested for arterial perfusion with red ink and radio-opaque dye, and then transposed into artificially created same-size defects. After introducing this flap in the clinic partially successful in first place we modified the flap to its definite design. Results Average cadaver flap size is between 11cm and 22cm of length, allowing to wrap the flap dorsally over the fingertip and way back to the palmar MCP- joint. The flap is based on the distal web space perforator which is commonly used by a DMCA flap and supercharged by an intercompartmental, supraretinacular artery. Donor sites were closed primarily with little tension. Application of the flap in the clinic resulted in satisfying functional and aesthetic outcomes. Conclusion The SISAP-flap is a new option for the reconstruction of extended finger defects and should be added to the reconstructive surgeon’s armamentarium of pedicled flaps, providing relatively short operating time and promising clinical outcome.