Sutures and surgery go hand in hand. Not even newer ways of closing wounds such as use of clips or staples will ever end this relationship. While staples and clips may be used externally for many types of wounds, internal procedures almost always need a type of a suture.
Sutures can be broadly classified into two groups:
Absorbable sutures as the name suggests will eventually be absorbed in the body and after some time there will be no trace of them. There are many types and sizes of these sutures and each type is best suited for a particular surgical job or part of the body. The strengths of these sutures also differ. Other differences include:
There are both natural and synthetic absorbable sutures. Each type is further classified into whether the strands making the suture are single or multiple. Single strand absorbable sutures are called monofilament while multiple strand types are called multi-filament absorbable sutures.
This is a monofilament synthetic absorbable suture made from polyester. They come plain or colored in FDA permitted dyes. This suture is best suited for internal soft tissue approximation. It is especially good in pediatric cardiovascular procedures and in tissues where growth is ongoing. The suture is good where support is needed for up to 6 weeks.PDO Sutures
This is a multifilament and braided absorbable suture made from polyglycolic acid. It is coated with N-laurin and L-lysine to make it smooth. The absorption time is about 90 days and is made plain or colored violet. The suture is very reliable and will remain effective through the critical wound healing time. It forms secure knots that are not likely to give way. It is good for subcutaneous wound closure and for various internal surgical uses.PGA Sutures
PGCL is a synthetic monofilament absorbable suture that comes dyed or plain. The main indication is in soft tissue approximation, repair and in ligating bleeders. It is not suitable for cardiovascular or neurovascular procedures. Tension strength gradually reduces and it's over in about 4 weeks. It has low incidence of inflammation. The elderly, malnourished or people with possible delayed wound healing should not use PGCL.PGCL Sutures
These are natural absorbable sutures made from purified collagen tissues of cows' intestines. It is suitable for quickly regenerating tissues. Some countries have phased out the use of catgut on human surgeries and are only used in vet operations.
These are sutures that are not degraded by the body. Although the body can try to do this, the process is so slow that the suture if left in place can remain there permanently. When used externally, these sutures have to be removed in about 7-10 days of surgery. As with the absorbable type of sutures, here there are also synthetic and natural types. These are further divided into mono-filament and multi-filament. Multifilament sutures are further divided according to the way their strands are connected. They can either be:
Each of these types is best for specific surgeries.
Nylon monofilament and multifilament sutures are made from long-chain aliphatic polymers of nylon 6. They are used in a wide variety of surgical situations. They can be used in ophthalmic, cardiovascular and even in neurosurgical procedures. They come dyed mostly in green or blue or even black. This enhances visibility during procedures. Nylon sutures have high tensile characteristics and hold firmly for the duration of time they are supposed to be in place. They easily go back to their shape even after being deformed. This is especially true for monofilament nylon sutures. There is minimal tissue reaction where nylon is used and so inflammation and infection rate is low.
Silk sutures are non-absorbable and made from natural proteinaceous silk material called fibroin. It is made into multifilament and braided type which is then coated with wax or silicon to reduce water retaining capacity and for easy handling. These sutures are appropriate for many types of surgeries such as ophthalmic, neurosurgery, cardiovascular and in closing many types of open traumatic or surgical wounds. Despite the fact that silk is not absorbable, it gradually loses its tensile power and for this reason may not be very ideal where permanent tension is required. The initial tissue reaction is minimal and soon the suture is encapsulated by tough fibrous connective tissues.Silk Sutures
Polyester sutures are synthetic and non-absorbable. They are made from polyethylene terephthalate. They are long lasting and their tension doesn't change. This characteristic and minimal tissue reaction makes them ideal for esthetic surgeries. Polyester non-absorbable sutures are also good for heart operations. They come coated or in plain format.Polyester Sutures
This is another class of synthetic non-absorbable sutures. It has good tensile and holding properties. It is made of isotactic crystalline stereoisomer of polypropylene. This suture is ideal for heart and vascular operations. Other areas of use include ophthalmologic and neurosurgical operations.Polypropylene Sutures
Sutures come in different sizes with needles of different sizes and of various tip characteristics. The type of suture and needle to use is determined by the operation and the specific part where the suture and needle are to be used.