Coronary or peripheral bypasses are the most frequently performed vascular operations. Although one million patients per year and around the world, undergo this intervention, its failure rate reaches 50%, because of poor vessel healing, leading to vessel graft occlusion. To improve the outcome of bypasses, researchers have developed a gel containing microparticles –‘GeM’, enabling the controlled release of a drug inhibiting cellular over-proliferation. Administered locally, directly on the bypass graft during surgery, this preventive treatment will reduce the risk of obstruction reoccurrence.