Improving CABG Surgery Amir Durrani Ben Hoagland Santosh Tumkur Lucas Burton Advisor: Thomas P. Ryan, Ph.D.

Project Goals Improve harvested vessel attachment Design device to aid in grafting Reduce suturing difficulty Improve local stabilization

Overview of Off-Pump CABG Coronary Artery Bypass Graft Procedure to introduce increased blood flow to occluded coronary arteries Harvested vessels grafted to coronary arteries

Market Potential 150,000 Off-pump CABG surgeries performed worldwide each year Charge for a CABG procedure ranges from $37,000 and $72,000 per case $26 Billion spent per year on CABG surgeries Use of beating heart techniques has grown more than 40% each year since 1997

Problems Stabilization is required to perform CABG on a beating heart Effective vessel-artery contact is imperative Complex suturing techniques required Current stabilizers don’t provide adequate local stabilization of graft site Heart positioning problems Heart hemodynamics

Device Development

Surgical Dimensions Coronary artery diameter(interior) – ~1-3mm Harvested vessel diameter(interior) – ~2-4mm Base plate length – ~14mm Shaft length - ~10mm

Device Version 1 Shaft inserted into vessel that is to be grafted and secured Device will then be inserted into the coronary artery; folding of base allows for easy insertion Device will adhere to the coronary artery when the upper surface of the base, containing an adhesive, is brought in contact with the upper inside surface of the coronary artery. 

Device Version 1 (cont.) The two vessels are now stabilized in close contact with one another and can be easily sutured together.  Alternative method of anastomosis would involve application of bio-adhesive to the upper surface of the elliptical base       

Stabilizer Improvement Modification to suction stabilizer Provides improved lateral stabilization Analogous to car-jack Spreads tissue up to one centimeter

Adhesive Will replace sutures (or reduce number needed) Comprised of cross-linked proteinaceous material High strength Strong rapid bonding between tissues Strong rapid bonding between tissue and synthetic materials Stronger than conventional fibrin adhesives

Adhesive Composition Cross-linking on a surface Water soluble proteinaceous material (27-53% by weight) Di- or polyaldehydes (weight ratio: 1 part to every 20-60 parts of protein Water insoluble rubbery or leathery proteinaceous solids (free of aldehydes) Tear strength of at least 75 g/cm^2

Plastics for Vessel Connector Encourage epithelialization Polyurethanes Expanded Teflon Prolene (polypropelene) Research into catheter plastics

Progress Made Solidified sutureless anastamosis device Began initial DesignSafe™ Analysis Consulted industry mechanical engineer about stabilizer foot design Contacted Ethicon’s principle materials engineer

Current Status Using SolidWorks™ 2001Plus and SolidEdge™ 2002 to model vessel connector for prototyping purposes Seeking feedback from Dr.’s Greelish and Merrill regarding our solutions Prototyping the stabilizer foot design

Future Plans Continue developing prototypes Refine possible solutions Continue consultation with surgeons and engineers for feedback Alter design based on feedback and prototype test results