SMP Bandage to prevent Colonic Anastomotic Leak
After colonic resections that may be necessary in case of cancer or diverticulitis, the two parts of the colon need to be reattached after the procedure. This procedure is called anastomosis and can be done through manual suture or staples. In any case, there are rates between 1% and 30% of anastomotic dehiscence reported in the literature.1 Anastomotic Leak is defined as a “leak of luminal contents from a surgical join between two hollow viscera.”2 If contents from the inside of the colon leak into the abdominal area, the consequences are various clinical signs like peritonitis; feculent wound, drain discharge, abscess, or fever. “Anastomotic leakage remains today a major cause of postoperative mortality and morbidity in colorectal surgery.”3
In order to minimize the risk of anastomotic leakage, we propose to develop a bandage made of SMP, which can wrap around the colon to seal the reconnected parts from the outside and therefore prevent any fluids to get into the abdominal cavity. The SMP will be fabricated into a tube shape that has a slightly smaller radius than the colon. The tube will then be radially expanded to a radius which is 1.5 times the radius of the colon. The device will be placed at the outside of the colon, covering the part where the anastomosis took place. The polymer will recover its shape due to the plasticization induced shape memory effect and will wrap tightly around to seal the colonic part after surgery against leakage. The SMP will be designed to be biodegradable in order to dissolve over the course of 3 to 6 months so that a second surgical procedure will not be necessary. The biodegradability and time span of degradation can be tuned by the number of ester groups in the polymeric backbone and the crosslink density of the polymeric network.
In addition, anti-inflammatory drugs and bioactive compounds that promote wound healing will be loaded into the polymer. This study will serve as a model to test the hypothesis that polymers loaded with bioactive compounds reveal positive effects on the healing process and can serve as a platform technology capable of concurrent drug delivery.
 Kingham, T. P.; Pachter, H. L., Colonic Anastomotic Leak: Risk Factors, Diagnosis, and Treatment. Journal of the American College of Surgeons 2009, 208 (2), 269-278.
 Peel, A. L.; Taylor, E. W., Proposed definitions for the audit of postoperative infection: a discussion paper. Surgical Infection Study Group. Annals of The Royal College of Surgeons of England 1991, 73 (6), 385-388.
 Alves, A.; Panis, Y.; Trancart, D.; Regimbeau, J.-M.; Pocard, M.; Valleur, P., Factors Associated with Clinically Significant Anastomotic Leakage after Large Bowel Resection: Multivariate Analysis of 707Patients. World Journal of Surgery 2002,26 (4), 499-502
We are exploring hydrogels for various biomedical applications. We are interested in hydrogels for:
- drug delivery systems
- wound healing patches
- scaffolds for 3D cell cultures and tissue engineering applications
In order to improve the biocompatibility of these materials, we are utilizing naturally derived polymeric biomaterials such as chitosan, collagen, and gelatin as starting materials for our custom hydrogels. Using materials that are naturally found in nature, and even within our own body, greatly reduces the foreign body reaction.