In this article, we will discuss Sutures and Ligatures in Abdominal Surgery (Definition and Suture Materials). So, let’s get started.
Sutures and Ligatures
Sutures and ligatures are widely used in surgery and for suturing minor or major lacerations following trauma. Their primary function is to hold wound in good apposition for the promotion of wound healing.
• Ligature: A ligature is a thread used to constrict and seal off a blood vessel, vein or artery (to ligate).
• Suture: The thread is a suture when it is used to stitch together the edges of various tissues, e.g., skin, fascia, muscle, tendon, peritoneum, etc. Hence a needle is always used for a suture (sewing) but
not for ligature.
Sutures and ligatures are classified as absorbable and non-absorbable, depending on the materials on which
they are made.
• Absorbable materials are digested by tissues during healing process and are made from collagen (animal protein) or synthetic polymers.
• Non-absorbable materials resist enzymatic digestion process and are usually made of inorganic materials.
1. Catgut plain – Used to suture mucous membrane of lips, tongues superficial laceration of the genital area. They are easily absorbed within 1 week.
2. Catgut chromic – Used to suture fascia, muscles or ligature of blood vessels. It is usually absorbed within 30-45 days.
3. Vicryl – same as above. Takes at least 70 days for absorption. Rapid vicryl is easily absorbed.
4. PDS (polydiaxone) – Expensive, takes at least 5 – 6 months to be absorbed.
However, vicryl is the most commonly used suture materials during surgery while closing in layers.
• Absorbable suture materials are those that are broken down. The original absorbable suture materials were plain and chromic “cat gut,” which actually consisted of processed collagen derived from the submucosa of animal intestines. Plain gut is broken down enzymatically after about 7 days. Chromic gut is collagen treated with chromium salts to delay break down. Chromic gut typically loses its strength after 2-3 weeks is completely digested after about 3 months.
• Now there are many synthetic absorbable materials made from polymers (e.g., Vicryl and Monocryl). These materials are broken down non-enzymatically by hydrolysis; water penetrates the suture filaments and causes breakdown of the polymer chain. As a result, synthetic absorbables tend to evoke less tissue reaction than plain or chronic gut.
1. Ethilon – Most commonly used to close and suture skin after surgery ortrauma to the skin. Cutting needles are usually used.
2. Prolene – Used to suture nerve, tendon or blood vessels. Preferable roundbody needles are used.
3. Silk and Linen – Have similar properties. They are very strong, but they areadherent to the tissues and can cause reaction or infection.
• Non-absorbable sutures are made of materials that are not readily broken down by the body’scenzymes or by hydrolysis. There are naturally occurring non-absorbable materials, e.g., silk, cotton, and steel).
• Synthetic non-absorbable materials (e.g., nylon and Prolene, Mersilene). In some cases, they are left in place indefinitely (e.g., when used to close the abdominal fascia), and in other cases they are removed after adequate healing has occurred (e.g., nylon sutures to close a superficial laceration).
Other suture materials that are also used are:
1. Staples – To close wound under high tension like scalp, trunk and extremities.
2. Strips and tapes – Used to close superficial laceration on the face.
3. Derma bond – Very expensive, ideal for simple laceration, but fact around the edges have to be removed.
The needles are made up of either of stainless steel or of carbon steel. Needles are chosen by the surgeon to suit his operating technique and it is largely because of the surgeon’s interest in improving suture efficiency. Surgical needles are of two types; those which have an eye through which have an eye through which the suture is threaded, and eyeless needles where the suture is inserted into the hollow hilt and held in position by swaging the metal around
Needles may also be classified by their point geometry, examples include:
• Taper (needle body is round and tapers smoothly to a point)
• Cutting (needle body is triangular and has a sharpened cutting edge on the inside).
• Reverse cutting (cutting edge on the outside).
• Trocar point or taper cut (needle body is round and tapered, but ends in a small triangular cutting point)
• Blunt points for sewing friable tissues.
• Side cutting or spatula points (flat on top and bottom with a cutting edge along the front to one side) for eye surgery.