What are Absorbable Sutures?

Two mechanisms, and why the distinction is the starting point

Every absorbable suture in general use is broken down by one of two processes. Synthetic polymers are broken down by hydrolysis: water reaches the ester bonds in the polymer backbone and cleaves them, and the chains shorten until the strand no longer carries load and, later, until there is no strand left. Catgut is not a polymer in that sense — it is purified collagen, a protein — and it is broken down by the body’s proteolytic enzymes.

The distinction is not academic bookkeeping. Hydrolysis is driven by water, which is present in any tissue bed. Enzymatic proteolysis is driven by the patient’s own inflammatory and enzymatic activity, which is a variable belonging to the patient rather than to the material. That is the difference a clinician is actually reasoning about when the two are compared, and it is a difference in mechanism — not, on its own, a statement that either behaves better.

Strength loss and mass loss are different timelines

This is the point the word “dissolvable” obscures. A suture does not hold at full strength and then vanish. Hydrolysis shortens polymer chains long before it has removed appreciable mass, so tensile strength falls away first and the material is cleared afterwards. The interval between the two can be substantial.

That is why the instructions for use quote strength retention and absorption period as two separate specifications rather than one lifetime. A material that is still physically present is not necessarily still supporting anything, and a material that outlasts the tissue’s need for support has not thereby become the safer option. The figures themselves are product-specific and belong to the controlled document; what belongs here is the reason there are two of them.

The material families

The natural material is catgut, made from purified collagen taken from the intestinal submucosa of ruminants, and supplied plain or chromicised — treated with a chromium salt solution, which alters how the strand resists enzymatic attack. It remains the only enzymatically absorbed suture material in general use, and the availability of natural-origin sutures is restricted in some markets; the regulatory status in your own market governs.

The synthetics are distinguished by monomer and by construction. PGA is a homopolymer of glycolide, braided and coated. Polyglactin 910 is a copolymer of glycolide and L-lactide, also braided and coated. Poliglecaprone is a copolymer of glycolide and epsilon-caprolactone, extruded as a monofilament. Polydioxanone is a poly(ether-ester) of p-dioxanone, also a monofilament; the ether oxygen in its backbone is what distinguishes its chain chemistry from the pure glycolide/lactide esters.

Braided and monofilament are genuinely different constructions rather than grades of the same thing. A braid is many fine filaments interlaced — wound in opposing directions so they cross over and under one another along the strand — which gives pliability and the way a knot seats, and which leaves interstices — the reason braided sutures are coated, and the reason capillarity is discussed for braids and not for monofilaments. A monofilament is a single extruded strand with no interstices at all. Each property points in its own direction, and which of them matters is decided by the case.

Dolphin Sutures first brought synthetic absorbable suture to the Indian market under the brand name Petcryl — the first synthetic absorbable suture manufactured in India.