Surgery: suture patterns - overview from Vetstream | Definitive Veterinary Intelligence

Introduction

Probably as many different suture patterns as there are suture materials. Patterns consist of two basic types:
- Interrupted - each stitch is cut and tied as a separate entity.
  - Advantages:
    - Allows precise adjustment of tension along the length of the wound.
    - Failure of a single knot may not cause wound to break down.
    - Suitable for all tissue types.
  - Disadvantages:
    - Time consuming to place.
    - More knots, therefore more suture material left in wound.
- Continuous - knots are placed only at the beginning and end of a running line of continuous stitches.
  - Advantages:
    - Less time consuming than interrupted sutures patterns.
    - Less suture material left in the wound.
    - Relatively fluid and airtight.
  - Disadvantages:
    - Failure of securing or finishing knot likely to lead to unraveling of entire suture line.
Suture patterns can also be classified as everting, inverting and apposing:
- Everting tends to turn the tissue edges outward.
- Inverting sutures tend to turn the tissue inward.
- Apposing sutures bring the tissue edges into direct contact without eversion or inversion.
Another differentiation in suture patterns is whether they are a simple or mattress (tension) suture:
- Mattress patterns:
  - Close an incision under tension better than simple patterns.
  - May slow down healing by compressing tissue on each side of the incision, compromising local blood supply.
  - Designed to withstand more tension by spreading the tension over a wider area.
  - May be appositional, inverting, or everting depending on whether suture material is placed full or partial thickness within the skin edge.

Suture knots

There are some guiding principles of knot formation that should be followed:
- Knots should be as small as possible to minimize foreign body reactions.
- After the first loop is tied in a knot traction should be maintained to avoid loosening.
- Extra knots do not add strength to an accurately tied knot.
Useful knots to learn:
- Aberdeen knot: the Aberdeen knot has been shown to be stronger and more secure than a surgeon's knot for ending a suture line. The Aberdeen knot is also of a smaller volume than a standard surgeon's knot. An Aberdeen knot tied with 3 throws and 2 turns has been shown to provide the maximum level of security.
- Sliding knot: useful for placing a ligature deep in a body cavity, it should always be covered with a square knot for security to prevent the knot loosening.