04.01 Needles & Sutures - Suture Needles
In this module you will learn about the different types and properties of needles and sutures.
In this module
04.01 Suture Needles
Many different types, sizes and shapes of needle are available. Most needles are curved, although straight needles are available. The choice of needle to be used depends on factors such as the nature of the tissue being sutured, the accessibility of the operative area, the gauge of suture material being used and the surgeon’s particular preference.
04.01.01 Suture Attachment
Almost all needles nowadays are atraumatic. A hole or channel is formed in the butt end of the needle and the suture is swaged or inserted into it. The suture will follow the needle's path without causing any further tissue damage and is therefore called 'atraumatic'.
Old fashioned needles had an eye and were threaded with a loop of suture. The suture caused more trauma than the needle alone, so the needle was called 'traumatic'.
04.01.02 Curved Needles Video 1
The choice of needle shape is often determined by the accessibility of the tissue that requires suturing. Curved needles are most commonly used for suturing and usually, the more confined the operative site, the greater curvature of needle is required.
The curvature may be 1/4, 5/8, 1/2 or 3/8 circle.
A range of lengths is available for any particular curvature.
The mid-portion of a curved needle is flattened to allow the needle holder to grip it firmly.
04.01.03 Curved Needles Video 2
These tables show the typical applications for a 1/4, 3/8 and 1/2 circle needle.
04.01.04 Curved Needles Video 3
These tables show the typical applications for a 5/8 circle, J-shape and compound curved needle.
04.01.05 Cutting Needles
Cutting needles have a triangular cross section. Each edge is extremely sharp, so the needle acts like three tiny scalpels slicing through tissue. This is effective for cutting skin but can cause damage in deeper parts of the body.
Every suture packet bears a symbol describing its needle's point.
04.01.05.01 Conventional Cutting Needles
Conventional cutting needles have the apex of the triangle on the inner, concave curvature (represented on the suture packet by an upward pointing triangle).
This needle is suitable for most purposes. Typical applications are skin, ligament, nasal cavity, tendon and oral.
04.01.05.02 Reverse Cutting Needles
Reverse cutting needles have the apex of the triangle on the outer, convex curvature (represented on the suture packet by a downward pointing triangle). This places the flat part of the point nearest to the edge of the incision and is said to reduce the likelihood of the needle cutting outwards.
Typical applications are skin, fascia, ligament, nasal cavity, tendon and oral.
04.01.05.03 Tapercut Needles
Tapercut needles are like two needles in one. They combine the initial penetration of a cutting needle with the minimal trauma of a round bodied needle. The cutting tip is limited to the point of the needle.
Penetrating skin with a tapercut needle is difficult and can cause trauma because of the need to grasp the skin edge very tightly with forceps. Consequently, tapercut needles are not recommended for suturing skin.
Typical applications are fascia, ligament, uterus and scar tissue.
04.01.06 Round Bodied Needles
Round-bodied needles are conical, with a circular cross-section. This is represented on the suture packet by a circle.
A round bodied needle's conical shape lets it find the path of least resistance through tissue. These needles are best for inserting sutures deep in a wound. They bend or snap if you try to force them through skin or tough fascia.
04.01.07 Straight Needles
A straight needle can be used without instruments, whereas a curved needle must be handled with dissecting forceps and a needle holder. However, the technique is cumbersome and there is a much higher risk of accidentally sticking yourself. For these reasons, suturing with a straight needle is not common and we recommend the use of curved needles.
A straight-body needle can be used to suture easily accessible tissue that can be manipulated directly by hand. Examples of straight-body needles include the Keith needle, which is a straight cutting needle used for skin closure of abdominal wounds, and the Bunnell needle, which is used for tendon/gastrointestinal tract repair.