Doctor, why don't you give me catgut?

This is the 5307th article of Da Yi Xiao Hu

When surgeons are talking to patients about surgery and explaining matters such as dressing changes and suture removal after surgery, a question they are often asked is "What? Do I need to remove the sutures on my wound? Why don't you use catgut? Catgut doesn't need to be removed." In an era without Internet communication, the concept of catgut could be so popular among the public, which is really impressive: gold and silver cups are not as good as the reputation of patients. But in most cases, the answer to this question is no: your wound does need to be sutured, and catgut cannot be used.

If this situation happens more often, it is necessary to have a serious talk about it. The so-called sutures that do not need to be removed are not as patients imagine, and can be used in any surgery.

Absorbable sutures

who I am?

Catgut, as the name implies, is an absorbable suture made from the small intestinal mucosal tissue of sheep (or cattle). Absorbable surgical sutures, as opposed to non-absorbable sutures, refer to sutures made of materials that can be absorbed by human tissue.

Where are you from?

According to the properties of the raw materials, absorbable sutures are generally divided into two categories: natural material sutures (such as catgut, animal tendon sutures, collagen sutures, etc.) and artificial synthetic sutures (such as polylactic acid, polyglycolic acid and other polymer materials).

Where are you going?

Natural material sutures are mostly composed of foreign tissue proteins, which need to be digested by enzymes in the human body to be degraded. Therefore, there will be obvious antigen rejection and tissue reactions during the absorption of the sutures, such as redness, swelling, exudation, pain, fibrous tissue wrapping and other inflammatory reactions. Artificial synthetic materials break and decompose high molecular weight polymer chains through hydrolysis, and the final degradation products are mostly water and carbon dioxide. Compared with absorbable sutures made of natural materials, the tissue reaction of artificial synthetic sutures is lighter. At present, they have gradually replaced natural material sutures and are widely used in clinical practice, but their degradation and absorption time is also relatively long.

Scope of application

The selection of surgical sutures should take into account the nature of the surgery, the sutured tissue, and the patient's condition. Any suture must first maintain a certain strength, sufficient to withstand the tissue tension during suture and until the tissue is fully healed. When the wound heals well and there are no abnormal conditions such as infection, diabetes, and malnutrition, the general time for removing sutures is: 4 to 5 days for the head, face, and neck; 6 to 7 days for the lower abdomen and perineum; 7 to 9 days for the chest, upper abdomen, back, and buttocks; 10 to 12 days for the limbs (can be extended near the joints), and the tension-reducing sutures need 14 days to be removed. However, the absorbable sutures commonly used in clinical practice usually take 2 to 3 months or even longer to be degraded by the body, and there are currently no sutures that can be completely degraded in 10 to 14 days. Due to the time difference with the wound repair process, after the sutured tissue is basically healed, the residual sutures continue to degrade and absorb. This process will continuously stimulate the body to produce tissue reactions, resulting in redness, swelling, induration, concurrent infection, cutting of the wound edge, stimulation of scar hyperplasia, and other rejection phenomena that are not conducive to wound healing. For example, catgut was once widely used in episiotomy sutures, but it is slowly absorbed and has rejection reactions. Some women even have sutures excreted from their bodies six months after surgery. Therefore, in order to reduce the rejection of sutures in the wound, it is better to remove the sutures in time.

summary

Absorbable sutures are more suitable for suturing deeper tissues inside the body, while the outer layer of the wound is best treated with non-absorbable sutures that need to be removed. A typical example is that absorbable sutures are not used in ophthalmic cataract and corneal surgeries, and the sutures still need to be removed after surgery. Choosing absorbable sutures just to save the trouble of removing sutures is not an ideal choice. There are two reasons for this: 1. Compared with non-absorbable sutures, the body has a greater tissue reaction to absorbable sutures, and not removing the sutures will affect the repair and healing of the wound; 2. Compared with traditional non-absorbable sutures, the price of absorbable sutures is often dozens of times higher or even more, which is not economically cost-effective.

References

1. Qiu Fazu. Surgery. People's Medical Publishing House, October 1998, 4th edition.

Author: Shanghai Tenth People's Hospital

Plastic Surgery Liu Guangpeng, deputy chief physician