Medtronic Chromic Gut Sutures. CHROMIC GUT sutures are absorbable sterile surgical sutures composed of purified connective tissue (mostly collagen) derived from the serosal layer of beef (bovine) intestines. They are packaged in a solution of 89% isopropanol, 10% water and 1% triethanolmaine. Chromic gut is treated with chromic salt solution. Mild chromic sutures are specially treated for ophthalmic and cuticular applications. The manufacture of catgut raw material, consisting of long ribbons of highly selected serosal tissue, ensures: Purity of collagen for optimal tensile strength and in-vivo performance; Uniform treatment with a buffered chromium salt solution, resulting in a chromic strand with a more predictable strength and uniform in-vivo absorption; Surface smoothness to facilitate knot run-down and knot strength, due to electronic polishing of each strand. CHROMIC GUT sutures are indicated for use in general soft tissue approximation and/or ligation, including use in ophthalmic surgery, but not in cardiovascular or neurological surgery.