When a junior surgical trainee is asked which suture they will use on the skin, the standard answer is whatever the boss prefers to use. This answer has two purposes – it maintains the status quo and covers the fact that many are unaware of different sutures. This basic overview should guide you.

The ideal suture material is usually sterile, easy to handle, strong, resistant to infection, and affordable. They must behave the way we want it to, i.e., consistent. It is challenging to produce the perfect suture and precisely why varied materials offer unique characteristics.

There are two categories of sutures:

Non-absorbable

These such as prolene suture get used for offering long-term tissue approximation. They are ideal for skin and removed later. Sometimes, they are used inside the body where they get retained. The non-absorbable sutures get used for vessel repair, bowel repair, tendon repair, and skin closure.

The prolene suture and nylon one offer good strength to low tissue reactivity and are hence used widely. Prolene 6-0 is one example here that is commonly used for facial wounds where the cosmetic outcome is essential. The low reactivity causes less scarring. They also get used widely for vascular anastomoses, abdominal wall closure, and C-section surgeries. They get dyed blue for helping with visibility.

Absorbable

The absorbable sutures get broken down by the body over time through hydrolysis and enzymatic degradation. The amount of time taken depends not only on the material but also on the insertion and the individual patent characteristics. The suture's absorption rate increases in patients owing to infection, fever, or protein deficiency.

Skin closure of the surgical wound gets achieved with absorbable sutures. One of them used in practice is Polyglactin 910 sutures. It is a sterile surgical suture made of copolymer, made of 90 per cent glycolide and 10 per cent L-lactide.

Even braided sutures under the absorbable ones are useful as they loosen at the surgical knot. But they may cause local tissue reaction.

Are catgut sutures still used?

The naturally made sutures like catgut do not get used as they were once. It is a good suture material made by twisting together the strands of bovine intestine collagen. They have excellent handling properties and are currently banned in Europe and Japan due to the risk of transmission of mad cow disease.

Does the size matter?

The strength and handling properties get affected by the thickness of the suture thread. Hence, these threads get manufactured in varied sizes. The size determines the diameter of the suture strand. The larger the number prefix, the smaller the diameter of the thread.