Sutures hold apposing tissues together to facilitate the healing process. Knowledge of the fundamental concepts regarding sutures, such as external configuration, strength, memory and types of materials is crucial to select the most suitable suture for each stage during a surgical procedure.
1. Physical Configuration
– Multifilament sutures can be braided or twisted. They provide greater knot security than monofilament sutures, which have more “memory”.
– Monofilament sutures are more resistant to serious infection than multifilament sutures and natural fibers.
2. Tensile strength
Tensile strength is defined as the weight required to break a suture divided by its cross sectional area. The designation is the number of zeros (1-0 to 10-0): the smaller the size, the lower the strength.
Knot strength is the force required to cause a knot to slip and is directly proportional to the friction coefficient for a given material.
4. Elasticity and memory
Elasticity is a material’s intrinsic ability to hold its original shape and length after being stretched.
Memory refers to the inherent ability of a material to return to its former shape after being manipulated, and is often a reflection of its stiffness.
5.Synthetic versus Natural Materials
Synthetic sutures provide greater uniformity, tensile strength and wound security, longer duration of support during wound healing and cause less inflammatory response than natural fibers.
6.Absorbable and non-absorbable Sutures
Non-absorbable sutures typically maintain tensile strength for more than two months, and many synthetic sutures remain in the incision permanently. Synthetic sutures provide longer wound security (300 days or more).
Knowledge of the characteristics of the sutures is crucial for the surgeon as each type of suture has specific characteristics which may make it appropriate for a specific circumstance.