Floor plan - 2013 Annual Meeting - American Association for Hand ...

Regenerative Acellular Collagen Tube Matrix as a Microvascular Conduit
Institution where the work was prepared: Cleveland Clinic Foundation, Cleveland, OH, USA
Wong Moon, MD; Cleveland Clinic Foundation
INTRODUCTION:
Autogenous vein is the only biologic graft available for vascular reconstruction. However, autogenous vein is limited by its quality, quantity,
diameter, and length. The purpose of this study is to determine if a human derived Acellular Collagen Matrix (ACM) tube graft can
be used as a microvascular conduit.
METHODS:
In 10 Sprague-Dawley 500g rats, 7mm long segment of aorta was excised. 1.75 to 2.0mm in diameter vascular conduits were created
from human derived ACM. These grafts were interpositioned between the two cut ends of the aorta and anastomosed in an end-toend
fashion using 12-30x magnifying surgical microscope. Animals were given heparin 100IU/kg before surgery and received daily
LMWH 1.5mg/kg for 7 days. Rats were observed daily to detect possible complications. Graft patency was check at 3 and 6 months.
Grafts were sent for histological examination.
RESULTS:
Post-operatively, all 10 rats appeared healthy and were active. Their limbs were viable. At the time of harvest, all rats had patent grafts
at 3 and 6 months. There was well incorporation of the graft material into the native aorta. No infections or aneurysms were present
during the follow-up period. The H & E stained graft tissue showed an intact collagen matrix with in-growth of endothelial and smooth
muscle cells.
CONCLUSIONS:
We report the first study that human derived Acellular Collagen Matrix (ACM) tube can be used as a vascular graft preparation. This
material can tolerate the high shear stresses of the aorta, can regenerate into a native artery, and has successful long-term patency.
Thermoreversible Poloxamers and Applications for Vascular Biology
Institution where the work was prepared: Stanford University, Stanford, CA, USA
Edward I. Chang, MD; Cynthia D. Hamou; Michael G. Galvez; Michael T. Longaker; Geo frey C. Gurtner; Stanford University
INTRODUCTION:
Conventional suture techniques for vascular anastomoses are time consuming and prone to thrombosis and restenosis due to intimal
damage and inflammation. We propose a novel sutureless technique using thermoreversible poloxamers.
METHODS:
Rheological studies determined the formulation of P407/P188 to obtain a phase transition temperature at 42°C. Anastomoses were performed
on Fisher rat aortas using P407/P188 and bioadhesives (n=30) and 10-0 nylon sutures (n=30). CT angiograms, burst strength
assays, histology, and scanning electron microscopy (SEM) were performed at designated timepoints. Tissue factor pathway inhibitor
(TFPI) ELISA was performed on media harvested from HUVECs exposed to heparin and heparinized P407/P188.
RESULTS:
A formulation of 17% P407 and 6% P188 achieved a phase transition temperature of 42°C which was used for all future experiments.
The average diameter of the rat aorta used for the end-to-end anastomoses in this study was 2.8mm, and the average diameter of the
iliac vessels used in the end-to-side anastomoses was 1.9mm. End-to-end anastomoses performed using P407/P188 were completed
more efficiently than the hand-sewn technique (10.0 ± 4.2min vs. 47.3 ± 5.0 min, p1500mm Hg,
p>0.05). Angiograms demonstrated equivalent patency, and flow through native aorta, hand-sewn anastomoses, and sutureless anastomoses
were not significantly different (26mL/sec vs. 27mL/sec vs. 29mL/sec respectively). Histology and SEM demonstrated less fibrosis
in the sutureless group compared with the traditional technique. End-to-side anastomoses performed with the hand-sewn technique
had 100% failure rate; however, end-to-side sutureless anastomoses were successful in 33% of operations performed (p