All sutures can be divided into two main groups: absorbable or non-absorbable (also called permanent). This depends on whether the body will naturally degrade and absorb the suture material over time. Absorbable suture materials also cover the original catgut. Catgut suture is a type of surgical suture that is naturally degraded by the body's own chemical substances called enzymes. This happens because of a biological process called proteolysis.
This is the breakdown of proteins in the body by multiple factors such as enzymes and heat. Catgut suture was made from pig or cow intestine, not from the gut of a cat. Absorbable sutures were in the beginning made of the intestines of sheep. Today, gut sutures are made of expressly prepared beef and sheep intestine, and may not be treated (plain gut) or tanned with chromium salts to increase their persistence in the body (chromic gut). However, the topic of our interest here is the chromic gut suture which is a variant treated with chromic acid salts. Catgut has been withdrawn from most parts of the world because pure catgut causes an intense tissue reaction as it is absorbed within three to five days. This makes it largely unacceptable today. Thus, we use catgut soaked in chromic acid as an alternative since it causes a less intense reaction and has a faster rate of absorption in comparison to synthetic absorbable sutures.
Chromic gut surgical sutures are made of a high quality raw material for great absorption and an extremely high tensile strength. Absorption of the sutures varies according to which type of body tissue it is sewn into. It is more brown rather than straw-colored, and has improved smoothness due to the dry presentation of the thread. It is otherwise similar to plain catgut. Absorption is complete by ninety days, and full tensile strength remains for at least seven days. This ultimate breakup makes it good for use in rapidly healing tissues and in inside structures that cannot be accessed again to see if the suture can be removed. The chromic gut sutures are sometimes coated, as the coating helps reduce tissue drag and the smoothness of the strands allow for efficient knots to be tied. However, the downside is that it slows down the rate of absorption by the body.
Chromic gut suture has high knot-pull tensile strength and good knot security due to extraordinary outstanding handling characteristics. It is used for all types of surgical procedures including general closure, ophthalmic, orthopedics and gastrointestinal surgery. It is absorbed faster in patients with cancer, anemia, and malnutrition. It also absorbed at a faster rate when used in the mouth and in the vagina, due to the existence of microorganisms. They are used therefore in many of the internal tissues of the body. When the suture is not needed any more, the fact that it disappears is an advantage, as there is no foreign material left inside the body and no need for the patient to have the sutures removed.