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Skin area quantification in preparation for concomitant upper extremity and face transplantation: a cadaver study and
Chad R Gordon1, Fatih Zor, Maria Siemionow
1Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. cgordon5@partners.org
Background:
Numerous experiments in composite tissue allotransplantation (CTA) have identified skin as the most antigenic, with recent experimentation from our laboratory finding a direct correlation between large antigenic skin loads and chimerism. Therefore, in preparation for clinical application of concomitant upper extremity (UExt) and face transplantation, we aimed to identify the exact skin quantities accompanying various upper UExt and concomitant scenarios using a cadaver study.
Methods:
Five fresh cadavers were obtained and dissections were performed to simulate five different UExt transplant levels. Exact skin quantities (cm²) and total body surface area (TBSA) percentages were calculated using digital image analysis for both unilateral and bilateral hand transplant levels. UExt measurements were then cross-analyzed with our laboratory's facial/scalp alloflap data for similar evaluation of various concomitant CTA scenarios.
Results:
Skin quantities for unilateral hand transplants ranged from 335 (± 58) to 787 (± 82) cm², and from 670 (± 117) to 1575 (± 163) cm² for bilateral. Concomitant CTA quantities (from "unilateral wrist-level with face" to "bilateral elbow-level with face/scalp") extended from 1010 (± 81) to 2766 (± 202) cm², totaling a range of 5.6% to 15.4% TBSA.
Conclusion:
The findings presented here, for the first time, define exact skin quantities and TBSA percentages accompanying unilateral, bilateral, and concomitant hand/face transplant scenarios. Unilateral UExt transplants contain between 335 and 787 cm² and bilateral between 670 and 1575 cm². Concomitant face/scalp and UExt transplants contain between 1000 and 2800 cm², equating 5% to 15% TBSA. Furthermore, there exists a tremendous void in research and some inconsistencies between animal investigation and clinical experience related to large skin-bearing CTAs. These concerns warrant further investigation by all teams pursuing concomitant CTA.
