TITLE:
Investigation of Open Abdomen Visceral Skin Graft Revascularization and Separation from Peritoneal Contents
AUTHORS:
Katharine E. Caldwell, Ross M. Clark, Brittany B. Coffman, Jacquelyn S. Brandenburg, Thomas R. Howdieshell
KEYWORDS:
Open Abdomen, Visceral Skin Graft, Mesothelial Cells
JOURNAL NAME:
Surgical Science,
Vol.9 No.1,
January
24,
2018
ABSTRACT: Background: Despite increasing survival following damage control laparotomy and open abdomen technique, little is known about the biology of visceral skin graft revascularization and separation from peritoneal contents. Methods: Following laparotomy for trauma, patients with visceral edema preventing fascial closure underwent Vicryl mesh closure followed by visceral split-thickness skin grafting and readmission graft excision and abdominal wall reconstruction. Utilizing laser speckle contrast imaging, immunochemical staining of histologic sections, and RT-PCR array technology, we examined the revascularization, microvascular anatomy, morphology, and change in gene expression of visceral skin grafts. Results: Ten patients ranging in age from 25 to 46 years underwent visceral grafting for cutaneous coverage of an open abdomen. Skin graft perfusion peaked at a mean of 350 PU by post-operative day 14 synchronous with closure of meshed interstices, and remained constant until excision. Time to graft excision ranged from 6 to 18 months. CD-31 immunostaining documented a significant (p = 0.04) increase in vascular surface area in excised grafts compared to control skin. Trichrome staining revealed an 8-fold increase in excised graft thickness. Mesothelial cells were identified within the dermal matrix of excised grafts. RT-PCR demonstrated significant up-regulation of genes involved in matrix structure and remodeling, cytoskeleton regulation, and WNT signaling; and down-regulation of genes involved in inflammation and matrix proteolysis in excised grafts compared to control skin. Conclusion: Our data document early visceral skin graft perfusion and a plateau in revascularization. Histology reveals a robust dermal matrix populated by fibroblasts and mesothelial cells within a complex supporting vascular network. Genetic analysis of excised grafts reveals growth factor, collagen, and matrix remodeling gene expression.