A Surgical suture or stitch, is a medical tool used by doctors and surgeons to hold body tissues together to close a wound. Application generally involves using a needle attached to a length of thread. Depending on the patients condition, a doctor will use the proper suture technique and material to stitch a wound or laceration shut.
There are a variety of sutures, which differ by needle shape and size as well as thread material and characteristics. The doctor will choose a material that's appropriate for the wound or procedure.
Types of sutures
Sutures come in various types, categorized by their materials and structure.
By Material:
- Absorbable: These sutures dissolve naturally within the body, eliminating the need for removal. They are either degraded via proteolysis or hydrolysis and should not be used on body tissue that would require greater than two months of tensile strength. Examples include:
- Gut: A natural monofilament suture used for internal soft tissue wounds or lacerations. It is not ideal for cardiovascular or neurological procedures because the body has the strongest reaction to this suture and will often scar over. It's not commonly used outside of gynecological surgery.
- Plain Gut (polyfilament): This suture maintains its original strength 7-10 days and full degradation occurs in 10 weeks. It has excellent elasticity allowing for adaptation to tissue swelling. It passes through the skin with very little tissue trauma occurrence. However, it is difficult to handle and has high tissue reactivity causing quick loss of tensile strength. It is best used in rapidly healing tissues with good blood supply such as the mucosal tissues.
- Chromic Gut (polyfilament): It can maintain original strength for 21-28 days and full degradation occurs in 16-18 weeks. It has excellent elasticity and can adapt to tissue swelling. It passes through the skin with very little tissue trauma occurrence. It has better handling than Plain Gut and has decreased tissue reactivity due to chromic salt coating. It is commonly used to close facial skin, mucosa, and genitalia.
- Fast Gut (polyfilament): This is treated with heat to further break down protein and allow for more rapid absorption in bodily tissues. It can maintain tensile strength for 3-5 days. It has excellent elasticity and can adapt to tissue swelling. It can pass through the skin with very little tissue trauma occurrence. However, it is only generally ideal for skin closure on the mucosa or face.
- Poliglecaprone (Monocryl): This synthetic monofilament suture is used for general use in soft tissue repair. It loses tensile strength quickly with 60% lost in the first week. All strength is lost within 3 weeks. It has a high tensile strength, excellent elasticity, minimal tissue reaction, and good initial knot security. However, since the material rapidly loses strength, it becomes unreliable in terms of security over time. This suture is most commonly used to close skin in an invisible manner. It is also ideal for subcutaneous and superficial tissue. However, it shouldn't be used for cardiovascular and neurological procedures.
- Polyglactin (Vicryl and Vicryl Rapid): These have two types, Polyglactin 910, and Polyglactin 910 Irradiated. Polyglactin 910 has a tensile strength that lasts for 28 days while Polyglactin 910 Irradiated is an irradiated Vicryl that breaks down faster than normal Vicryl and losses all tensile strength in 5-7 days. Both have minimal tissue reaction, good tensile strength, and good knot security. Polyglactin 910, a synthetic braided suture, is good for repairing hand or facial lacerations, and subcutaneous tissue while 910 Irradiated is good for the scalp and facial lacerations. However, both are not recommended for cardiovascular and neurological procedures.
- Polydioxanone (PDS): This synthetic monofilament suture is very strong and flexible and can be used for many types of soft tissue wound repair such as abdominal closures as well as for pediatric cardiac procedures. It is also ideal for deep wounds and trauma surgery. Its tensile strength lasts for 36-53 days. It has minimal tissue reaction, but handling can be difficult.
- Polyglycolic acid (Dexon): A synthetic polymer that loses all tensile strength in 25 days. It can be undyed or dyed for visibility. It is strong, has minimal tissue reaction, has good handling, but poor knot security. It is commonly used for internal organs, subcutaneous tissues, and soft tissues.
- Polyglyconate (Maxon): A synthetic, absorbable monofilament suture material that loses 75% of its tensile strength after 40 days. It has minimal tissue reaction, excellent tensile strength, and good handling. It is commonly use on subcutaneous tissue and is often use as an alternative to PDS due to better handling and slightly superior tensile strength.
- Non-absorbable: These sutures hold greater tensile strength for longer periods of time and are not subject to degradation. These type of sutures can all be used generally for soft tissue repair, including for both cardiovascular and neurological procedures. They are appropriate for tissues with a high degree of mechanical or shear force (ie. tendons). They are also very convenient to use due to less thread memory. However, these sutures need to be removed after healing is complete. Examples include:
- Nylon: It comes in monofilament or polyfilament versions. The monofilament version has poor handling and poor knot security due to high material memory while the polyfilament version has good knot security and usability. Both types have excellent tensile strength. They are strong, smooth, and relatively inert, good for skin and general surgery.
- Silk: This is a braided natural suture. Surgical silk is a protein derived from silkworms that is coated to minimize friction and water absorption. This material has good tensile strength, is easy to handle and has excellent knot security. However, it is rarely used internally due to its significant tissue reaction which causes loss of tensile strength over months. Due to advancements in sutures, surgical silk are not often indicated. However, they are still good for cosmetic surgery and delicate tissues, and are still commonly used in dentistry for mucosal surfaces or to secure surgical tubes on the body's surface.
- Polypropylene (Prolene): A synthetic monofilament suture often used in skin, vascular surgery, and temporary tarsorrhaphy sutures. They are fairly stiff and have lower tensile strength than other synthetic non-absorbable sutures. They retain tensile strength after implantation and have low tissue reactivity. They can be dyed or undyed.
- Polyester (Ethibond): Very strong and durable, used for high-tension wounds and tendon repair. It is composed of polyethylene terephthalate fibers. They have minimal memory, and hold knots well. However, this suture can create more tissue trauma when passing through the skin and is more expensive than its counterparts.
- Polybutester (Novarfil): It is a copolymer of polyester. Like polyester, it has low tissue reactivity. It has good handling, high tensile strength that is greater than most other monofilaments, and has good elasticity during increasing edema. It is used in tendon repairs and general soft tissue approximation and ligation.
- Surgical Steel: It is a made up of a synthetic mixture of multiple alloys. Its tensile strength is exceptional with very little tissue reactivity, thus maintaining minimal degradation over time. However, it has very poor handling. It is commonly used in orthopedics, and sternum closure.
By Structure:
- Monofilament: Made from a single strand of material, offering smooth passage through tissue and reduced risk of infection.
- Multifilament or polyfilament: Made from multiple strands twisted together, offering greater strength and grip but higher risk of infection.
By Size and Needle:
- Size: Sutures are categorized by diameter (e.g., 2-0, 3-0, etc.), with smaller numbers indicating thicker sutures.
- Needle: The needle attached to the suture determines how it's used. Different needles have varying shapes and curves for different tissue types and access points.
Additional Factors:
- Coating: Some sutures are coated with antibiotics to reduce infection risk.
- Dyeing: Some sutures are dyed for better visibility during surgery.
Uses
Sutures have a wide range of uses in medicine, primarily related to wound closure and tissue repair.
Wound closure:
- Surgical incisions: Closing surgical incisions after various procedures, from skin grafting to organ transplants.
- Lacerations and traumatic injuries: Stitching together open wounds caused by accidents, falls, or other trauma.
- Internal anastomosis: Joining blood vessels or other internal structures during surgery.
Tissue repair:
- Hernia repair: Repairing weakened areas in the abdominal wall to prevent organs from protruding.
- Tendon repair: Reattaching or strengthening damaged tendons to restore joint function.
- Facial reconstruction: Repairing facial fractures, defects, or burns to improve appearance and function.
- Other plastic surgery procedures: Shaping and repositioning tissues for cosmetic or functional purposes.
Other uses:
- Drainage: Placing sutures to create a small opening for draining fluid or pus from an abscess or infection.
- Ligatures: Tying off blood vessels to control bleeding during surgery.
- Eyelid surgery: Repairing drooping eyelids or ptosis.
- Dental procedures: Closing gum tissue after tooth extractions or other oral surgery.