Omental roll-up: a technique for islet engraftment in a large animal model.
BACKGROUND
Attrition of transplanted islets is significant after hepatic embolization. This study was designed to investigate a novel surgical technique for islet transplantation into the omentum. This site allows placement of the islets in a three-dimensional (3D) matrix, with growth factors, to temporarily culture the islets in vivo while revascularization progresses.


METHODS
Five female dogs (three partial and two total pancreatectomies) received an autologous islet transplant in the omentum. Islets were suspended in 1 mL of PBS containing 10 ug of vascular endothelial growth factor (VEGF). Fresh autologous plasma (10 mL) was mixed with the islet/VEGF suspension. The coagulum containing the islets and VEGF was then placed on the greater omentum. The leading edge of omentum was rolled up to secure the islet/VEGF/coagulum in position and to present the thin islet layer with two omental surfaces for implantation. Omentum was recovered at 2, 13, 21, 42, and 180 d.


RESULTS
Immunohistochemical staining for synaptophysin, glucagon, and insulin confirmed the presence of transplanted islets in all omenta. Insulin and C peptide production from the omental islets was confirmed in portal venous samples, and normalization of morning glucose levels beginning on day 7 was seen in the total pancreatectomy experiment.


CONCLUSIONS
Autologous islets implant in rolled-up omentum when placed as a VEGF/autologous plasma coagulum. This technique has potential benefits, including the opportunity to accelerate revascularization and to investigate local strategies for modulating the immune response.
Hefty
Thomas R
TR
Division of Renal and Pancreas Transplantation, Virginia Mason Medical Center, Seattle, Washington 98101, USA. urotrh@vmmc.org
Kuhr
Christian S
CS
Chong
Kian Tai
KT
Guinee
Donald G
DG
Wang
Wenjing
W
Reems
Jo A
JA
Greenbaum
Carla J
CJ
D000818:Animals; D001786:Blood Glucose; D001804:Blood Transfusion, Autologous; D004285:Dogs; D005260:Female; D016381:Islets of Langerhans Transplantation / Q000379:methods*; D009852:Omentum; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage
D001786:Blood Glucose; D042461:Vascular Endothelial Growth Factor A