In general, sutures come in two distinct types: absorbable and non-absorbable. Wound closure may also be augmented by or accomplished by the use of stainless steel staples, wound clips, and surgical glue.

Absorbable sutures are capable of being broken down by the body's inflammatory response and are used internally to close organs, fascial planes, and subcutaneous tissues. Absorbable sutures can also be used to close skin but only in a subcuticular or completely buried pattern. Absorbable sutures should not be exteriorized. All of the absorbable sutures absorb fluid and might wick external fluids with bacteria into a surgery site. The braided sutures are particularly notorious for doing this.

Non-absorbable sutures are generally used to close skin and must be removed after wound healing is complete. There are some procedures where non-absorbable sutures may be placed internally but they cannot be removed.

Surgical staples are a fast, easy way to close the skin. They are very useful but require application using a staple gun and there is a specific device required for removing them.

Surgical glue is useful for closure of small wounds or surgical sites and we have used it to augment the placement of catheters or transducers within blood vessels. Although similar to products like Krazy Glue, surgical glue is designed to have a minimal exothermic reaction. Glues available in hardware stores should not be used on tissue!

Suture types

Recommended size of suture for specific purposes

Needles are required to place sutures and they come in 2 main types: taper and cutting. Taper needles, on cross section are perfectly round and this round body tapers to a sharp point. This results in a round tunnel in the tissue that the suture can sit in. On cross section, cutting needles are triangular and the 3 edges are sharpened to a cutting surface. Cutting needles produce a triangular hole that is not as secure for holding suture as the round hole provided by tapered needles. However, cutting needles are needed to pass suture through skin, particularly the dense connective tissue of the dermis, and also through other hard or dense tissues. Therefore, in general terms, taper needles are for suturing internal organs, fascia, and subcutaneous tissue whereas cutting needles are used to close skin.

Needles come in a wide range of sizes and shapes. Most common are the 3/8 to 1/2 circle needles but, depending upon the need, you can also purchase straight, serpentine and partially curved needles. Size and shape of the needle is a feature of the suture being used, the procedure involved, and the surgeon's preference.

Comparison Chart for Needles

 There are a wide variety of suture patterns and all have fairly specific uses. For a detailed review you are advised to read a surgery text.

For general closure we recommend the use of fairly simple patterns:

Simple interrupted: These are single sutures tied with a square knot or, if there is slight tension, a surgeon's knot. These are used to close body cavities (i.e. the linea alba for abdominal surgery) and the skin.

Simple continuous: This is a simple suture secured at both ends with a square knot and is used to quickly close a line. Commonly used to close the subcutaneous tissue in effort to provide a water tight seal. The disadvantage of a simple continuous pattern is you are relying on 2 knots to hold the suture line. If one knot fails the entire line will dehisce. We therefore do not recommend this for closing body cavities or skin.

Learning how to place sutures and how to tie knots in surgery is vital. Most common errors conducted by neophyte surgeons (other than breaks in asepsis) relate to suture placement and tying "granny knots" instead of square knots.