Absorbable Vs Non-Absorbable Suture

Historically, healers or medical practitioners utilized the adaptation of various materials such as animal tendons, intestines, horsehair and cotton to approximate wounds for healing. Since then, the world of suturing and ligature has evolved to include synthetic and adhesive materials that provide the most ideal environment for healing by primary intention. The expansive variant of sutures in the current market can be characterised into definite classes, but one apparent characteristic which describes sutures is their level of degradation.

Absorbable Vs Non-Absorbable Suture

Absorbable sutures are customarily manufactured from mammalian collagen which is digested through enzymatic degradation or synthetic polymer that undergoes hydrolysis of its filament structure with the course of absorption time. The healing process for wounds closed with absorbable sutures is triggered by a leukocyte cellular response which removes both cell debris and physical suture material, causing a steady reduction of tensile strength of the affected suture. Likewise, non-degradable sutures excite a tissue response through fibroblast activation and frustrated phagocytosis where macrophages and foreign body giant cells strive to digest a non-degradable suture.

Natural Absorbable Suture

Natural absorbable suture or more commonly called surgical gut are constructed from synthesized monofilaments of highly purified collagen with examples of origin including beef intestine serosa or sheep intestine submucosa. Plain surgical gut offers multi-purposes in the medical field but are typically used for approximating and ligating the epidermis, superficial blood vessels and subcutaneous tissue. Generally, the tensile strength of a plain surgical gut may last for 7-10 days with completed absorption by 70 days. The heat-treated counterpart offers a more rapid absorption rate and is suitable for the closure of wounds in the delicate buccal mucosa, eye and external closure for rhinoplasty ligation.

Synthetic Absorbable Suture

Synthetic absorbable suture shows high favouritism in the field of plastic surgery for their biodegradability and relatively low tissue reaction. A common example for suture under this category is Vicryl, a braided suture made from a copolymer of lactide and glycolide which formula is later improvised to include a coating of polyglactin 370 and calcium stearate to produce Coated Vicryl which has improved tissue handling. Vicryl Rapide is another variant of the composition but the strands are treated with gamma rays to reduce molecular weight. In general, its usage is ideal for superficial soft tissue mucosa and skin.

PDS II (Polydioxanone) is a polyester monofilament construct with a longer absorption rate and has the advantage of minimal tissue reaction. Due to this, it is favoured in the setting of ophthalmic, cardiovascular and pediatric surgeries. Likewise, Monocryl which is designed for skin closure due to its optimal tensile strength and absorption rate is commonly used for subcuticular skin closures such as skin graft and breast wound closure.

Natural Non-Absorbable Suture

Although silk suture falls under the category of non-absorbable material, material scientists consider its composition degradable through progressive enzymatic degradation that leads to reduction of suture tensile strength. Silk suture is made from natural filaments produced by silkworm which are tightly braided, dyed and coated with waxes or silicone. Another example of suture under this category is multifilament surgical stainless steel which is utilized in plastic surgery typically for reconstructing a sternal wound or external fixation of a hand fracture.

Synthetic Non-Absorbable Suture

Nylon is an example of material under this suture category with extensive application in skin ligation, vessel approximation and microsurgery. In the field of orthopaedic, coated Mersilene (polyethylene terephthalate) is favourable for ligament or tendon repair. A widely utilized synthetic monofilament called prolene offers superior outcome for more aesthetic result due to delayed sinus formation and is used to approximate facial lacerations.

Conclusion

With the increased variety of suture availability, surgeons have an array of selections of a highly improvised suture with advantageous extrinsic and intrinsic properties. Although they all lend a role in wound closure with primary healing, some over added advantage of lower reactivity, antimicrobial properties and even ease of handling while maintaining reliable ligation performance.