TITLE:
The Effect of Projection Microstereolithographic Fabricated Implant Geometry on Myocutaneous Revascularization
AUTHORS:
Ross M. Clark, Kirsten N. Cicotte, Paul G. McGuire, Elizabeth L. Hedberg-Dirk, Thomas R. Howdieshell
KEYWORDS:
Wound Healing, Angiogenesis, Stereolithography, Implant Geometry
JOURNAL NAME:
Surgical Science,
Vol.5 No.12,
December
3,
2014
ABSTRACT: Understanding cell
behavior inside three-dimensional (3D) microenvironments with controlled
spatial patterning of physical and biochemical factors could provide insight
into the basic biology of tissue engraftment, vascular anastomosis, and
revascularization. A simple layer by layer projection microstereolithography
(PμSL) method was utilized to investigate the effects of a nonporous and porous
bioinert barrier on myocutaneous flap engraftment and revascularization. A
cranial-based, peninsular-shaped myocutaneous flap was surgically created on
the dorsum of C57Bl6 mice. Porous (SP) and nonporous (S) silicone implants were
tailored to precise flap dimensions and inserted between the flap and recipient
bed prior to sutured wound closure. Porous implant myocutaneous flaps became
engrafted to the recipient site with complete viability. In contrast, distal
cutaneous necrosis and resultant flap dehiscence was evident by day 10 in
nonporous implant flap mice. Laser speckle contrast imaging demonstrated flap
revascularization in (SP) mice, and markedly reduced distal flap reperfusion in
(S) mice. Histologic analysis of day 10 (SP) flaps revealed granulation tissue
rich in blood vessels and macrophages growing through the implant pores and
robust neovascularization of the distal flap. In contrast, the nonporous
implant prevented tissue communication between recipient bed and flap with lack
of bridging inflammatory cells and neovasculature and resultant distal tissue
necrosis. We have fabricated porous and nonporous silicone implants via a
simple and inexpensive technique of PμSL. Using a graded-ischemia wound healing
model, we have shown that porous implants allowed contact between flap and
recipient bed resulting in proximal flap arteriogenesis and neovascularization
of the distal flap. Future research will utilize variations in implant pore
size, spacing, and location to gain a better understanding of the cellular and
molecular mechanisms responsible for myocutaneous flap engraftment, vascular
anastomosis, and revascularization.