History and Development of Suture

Rudra Narayan Saha
Research Scholar
Dr B R Ambedkar National Institute of Technology, Jalandhar, Punjab, India
Email Id – rudenarayansaha37469@gmail.com

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Introduction

A suture is a biomaterial tool that can be made of natural or artificial materials and is used to ligate capillaries and join tissues together. Thus its primary purposes are to bind and secure tissues together after separation caused by trauma or surgical intervention. It may also refer to a technique for mechanically closing a wound. Dead space must be eliminated, tension must be distributed evenly along deep suture lines, tensile strength must be maintained throughout the scar until tissue tensile strength is sufficient, and the epithelial portion of the closure must approximate. Sutures are the most frequently used components in wound closure, despite the fact that there are other mechanical wound closure techniques like staples, tape, and adhesive. Sutures have experienced tremendous growth over the past 20 years and are now the largest category of biomaterials, with a market worth more than $1.3 billion annually.(Pillai & Sharma, 2010) A thorough examination of the production, characteristics, biodegradability, and efficiency of suture materials has not recently been seriously attempted, despite the publication of numerous evaluations of suture materials.(BELLAS, 2015)

Characteristics of Suture Materials

The ideal suture should not end up causing any tissue reaction and be completely biologically inert. The surgeon could handle and knot it securely with ease. The following qualities a perfect suture ought to have

 1. handling must be easy

 2. cause little tissue reaction

3. Inhibits the growth of bacteria

4. be extremely strong in tensile tests

5. are simple to sterilise

6. don’t cause an allergic reaction

7. elicit no cancer-causing effects

8. absorbed after completing its activity

So, in addition to being extremely strong, a suture should be able to easily dissolve in body fluid and lose strength at the same rate that the tissue gain. It wouldn’t encourage complications or cause them.(David, 2005) Sutures should, in short, approximate wounds in the most secure way for a sufficient amount of time with the least amount of interference with the natural healing process. Bennett takes into account additional factors like the presence of infection, tissue characteristics, the location of the wound, tension on the wound’s edges, the patient’s age and overall health, cosmoses, colour, speed, and cost.(Pillai & Sharma, 2010)

Hardly a single suture material can meet all of these requirements . Because types of tissues have different needs for sutures, the surgeon must select the appropriate one for the surgical procedure that will be performed. Different tissues have different suture support needs; some, like muscle, subcutaneous tissue, and skin, can heal in a few days, while others, like fascia and tendons, can take weeks or even months. Additionally, the rate of tissue healing will vary depending on a number of factors, including disease, infection, respiratory issues, obesity, collagen disorders, malnutrition, malignancy, and medications like cytotoxics and steroids.(PARK, 2011)

Important terms for describing Suture

No.	Term	Description
1	Absorbable	Progressive loss of mass or volume of suture material; Though it is not correlate with initial tensile strength
2	Breaking strength	Range  of tensile strength at which suture failure starts
3	Elasticity	Measuring   the ability of the material to regain its original shape and length after deformation
4	Fluid absorption	Ability of fluid take up after immersion
5	Knot-pull tensile strength	Breaking strength of knotted suture material (gradually weak 10–40% after deformation by knot placement)
6	Memory	capability of suture to return to or maintain its original gross shape (related to elasticity, plasticity, and diameter)
7	Non absorbable	Surgical suture material that is relatively unaffected by the biological activities of the body tissues and is therefore permanent unless removed
8	Plasticity	Measure of the ability to deform without breaking and to maintain a new form after relief of the deforming force
9	Pliability	Ease of handling of suture material; ability to adjust knot tension and to secure knots (related to suture material, filament type, and diameter)
10	Capillarity	Extent to which absorbed fluid is transferred along the suture
11	Straight-pull tensile strength	Linear breaking strength of suture material
12	Tensile strength	Measure of a material or tissue’s ability to resist deformation and breakage
13	Wound breaking strength	Limit of tensile strength of a healing wound at which separation of the wound edges occurs
14	Fluid absorption	Ability to take up fluid after immersion

Classification

In terms of their performance, suture materials are generally classified into two broad categories: absorbable and non-absorbable. Absorbable suture materials lose their entire tensile strength within 2 to3 months; those that retain their strength longer than 2 to 3 months are non-absorbable. The absorbable suture materials are catgut (collagen sutures derived from sheep intestinal submucosa), reconstituted collagen, poly-glycolide (PGA), poly(glycolide-lactide) random copolymer (Vicryle), poly-p-dioxanone (PDS®, PDSfi®), poly(glycolide-trimethylene carbonate) block copolymer (Maxon®), poly(glycolide-£caprolactone)(Monocryle), and Glycolide-Trimethylene Carbonate block copolymer (Biosyn8 ). The nonabsorbable sutures are divided into the natural fibers (i.e., silk, cotton, and linen), and man-made fibers (i.e., polyethylene, polypropylene, polyamide, polyester, poly(tetraftuoroethylene) (Gore-Tex®), and stainless steel). (PARK, 2011)

Sutures also divided into categories based on how they are made (monofilament, braided, and twisted). Because sutures are categorised as medical devices, the Food and Drug Administration (FDA) has regulatory authority over their production. Located in Rockville, Maryland, the United States Pharmacopeia (USP) is a nonprofit, non-governmental organisation that offers manufacturing standards and testing for the industry. For the purpose of standardising and comparing suture materials that correspond to metric measurements, the USP system was established in 1937. Collagen, synthetic absorbable sutures, and nonabsorbable sutures are the three types of sutures. These are :.

Class I – Monofilament, twisted, or braided constructions made of silk or synthetic fibres.

Class II: Fibers made of cotton, linen, or coated natural or synthetic materials, where the coating increases suture thickness without enhancing strength.

Class III: Metal wire which is either monofilament or multifilament in design.(Chu, 2013)

Suture Size

Suture materials are also classified according to their size. Currently, two standards are used to describe the size of suture materials: United States Pharmacopoeia (USP) and European Pharmacopoeia (EP).table  summarizes both EP and USP standards. The USP standard is more commonly used. In the USP standard, the size is represented by a combination of two Arabic numerals: a 0 and any number other than 0, like 2-0 (or 210). The higher the first number, the smaller the suture material. Sizes greater than 0 are denoted by 1,2,3, etc. This standard size also varies with the type of suture material. (Byrne & Aly, 2019) Size is represented by zeroes and describes the suture strand’s diameter. The resultant strand diameter is smaller the more zeroes there are in a suture size (e.g., 4-0 is larger than 5-0). The strand’s tensile strength decreases with decreasing suture size.(PARK, 2011)(Pillai & Sharma, 2010)  In the EP standard, the code number ranges from 0.1 to 10. The corresponding minimum diameter (mm) can be easily calculated by taking the code number and dividing by 10. The EP standard does not separate natural from synthetic absorbable sutures as the USP standard does. Because a range of diameters is permitted for each USP suture size, the tensile strength (force/cross sectional area) of sutures of the same USP size may be different from each other. For example, two polypropylene sutures of the same USP size from two different manufacturers having the same tensile breaking load may have different tensile strengths because of a possible difference in suture cross sectional area due to slightly different diameters.(David, 2005) The polypropylene suture with a smaller diameter may have a higher tensile breaking strength than the one with a larger diameter.(USP 29, 2007)

Suture Size Classification

Uses of different sizes of suture

History of suture

Absorbable natural sutures

Absorbable Synthetic Sutures

Nonabsorbable sutures

(Tajirian & Goldberg, 2010)(Muffly et al., 2011)(Goel, 2016)(PARK, 2011)(Pillai & Sharma, 2010)

Design

Sutures can be used for a variety of purposes. Sutures used in cataract surgery are different from those used in abdominal surgery, for instance. Since not every operation is best served by a specific type of suture, Sutures with various qualities have been developed by surgeons and medical designers. While one may be extremely strong but perhaps a little more challenging to knot, another may be more absorbable but less flexible. This offers surgeons a variety of options. A new suture’s designers must consider a variety of factors. Not only along the suture’s length but also at the knot as the rate of suture degradation is crucial. Some sutures must be elastic in order for them to stretch without breaking. Others must remain firm. Manufacturers of sutures use specialised testing and research equipment for study suture.(Pillai & Sharma, 2010)

 A monofilament’s smooth surface makes it easy to pass through tissue. However, because they are less flexible than multifilament construction, they can be challenging to handle and tie. nearly all monofilaments also possess “memory.” This memory causes a suture to retain the shape it had when it was packaged, making it more challenging to manipulate. While some memory can be relaxed, not all sutures benefit from this. When making multi-filaments, multiple filaments or strands are braided or twisted together. This produces a strong, flexible, and manageable suture. When compared to smooth monofilaments, multifilament sutures are more difficult to pass through tissue, and the resulting “tissue drag” can result in tissue trauma. The use of coated braided materials greatly reduces these issues.(Chu, 2013)

Coating Materials

In order to improve the handling properties of suture materials, particularly braided or twisted sutures, such as a reduction in tissue drag while passing through the needle duct and the simplicity during the knotting process, knots slide down the suture. Beeswax, paraffin wax, silicone, poly (tetrafluoroethylene), and others are common coating materials. A coating material with a chemical characteristic similar to the intended use of the suture is in vogue. The coatings  depend on whether the suture is absorbable or non-absorbable.(Pillai & Sharma, 2010)

The polymer Poloxamer 188 and calcium stearate with a copolymer of glycolic acid (GA) and lactic acid (LA) are both absorbable coatings. Sutures that are non-absorbable can have coatings made of wax, silicone, fluorocarbon, etc. Additionally, sutures can be coloured to make them visible during surgery. All dyes and coatings must be FDA-approved. Logwood extract, chromium-cobalt-aluminum oxide, ferric ammonium citrate, pyrogallol, D&C Blue No. 9, D&C Blue No. 6, D&C Green No. 5, and D&C Green No. 6 are some of the dyes that are permitted. Steel, either carbon or stainless, is used to make suture needles. The needles could be electroplated or nickel-plated. Along with cardboard and plastic, packaging materials also include foil that is resistant to water, like aluminium foil.(PARK, 2011)

Conclusion

Surgical suture materials have developed into core products of a mature industry over the years. To better meet specific surgical needs, new sutures are constantly being created. basic supplies are modified according to their intended use to give the surgeon a suture material of the utmost quality. The present day user qualities of biologically inert, synthetic, absorbable, and nonabsorbable threads have approaching the limit of the requirements imposed by modern surgery.(Pillai & Sharma, 2010) This calls for more development in this area, which can be expected if production methods for strong, elastic thread made of biocompatible, absorbable natural polymers—such as polyoxyalkanoates, collagen, chitin, alginate, etc.—are developed. Suture materials with potential for anaesthetic and anti-neoplastic functions as well as anti-microbial activity are receiving more and more attention from researchers.

References

BELLAS, J. E. (2015). Suture studies. 1126(April 12), 1119–1126.

Byrne, M., & Aly, A. (2019). The surgical suture. Aesthetic Surgery Journal, 39, S67–S72. https://doi.org/10.1093/asj/sjz036

Chu, C. C. (2013). Types and properties of surgical sutures. In Biotextiles As Medical Implants. Woodhead Publishing Limited. https://doi.org/10.1533/9780857095602.2.232

David, L. D. (2005). W O U N D C L O S U R E M a N Ua L Preface. 8–25. http://www.uphs.upenn.edu/surgery/Education/facilities/measey/Wound_Closure_Manual.pdf

Goel, A. (2016). Surgical Sutures – A Review. Delhi Journal of Ophthalmology, 26(3), 159–162. https://doi.org/10.7869/djo.161

MOY, R. L., WALDMAN, B., & HEIN, D. W. (1992). A Review of Sutures and Suturing Techniques. The Journal of Dermatologic Surgery and Oncology, 18(9), 785–795. https://doi.org/10.1111/j.1524-4725.1992.tb03036.x

Muffly, T. M., Tizzano, A. P., & Walters, M. D. (2011). The history and evolution of sutures in pelvic surgery. Journal of the Royal Society of Medicine, 104(3), 107–112. https://doi.org/10.1258/jrsm.2010.100243

PARK, J. B. (2011). Biomaterials science and engineering. http://www.imcdb.lt/courses/regeneraciniu-organizmo-galimybiu-ir-mechanizmu-tyrimai-ir-jais-pagristu-gydymo-technologiju-kurimas/

Pillai, C. K. S., & Sharma, C. P. (2010). Review paper: Absorbable polymeric surgical sutures: Chemistry, production, properties, biodegradability, and performance. Journal of Biomaterials Applications, 25(4), 291–366. https://doi.org/10.1177/0885328210384890

Steward, S. P. (1951). Measurement of tensile strength of suture materials. Journal of Scientific Instruments, 28(4), 114–115. https://doi.org/10.1088/0950-7671/28/4/309

Tajirian, A. L., & Goldberg, D. J. (2010). A review of sutures and other skin closure materials. Journal of Cosmetic and Laser Therapy, 12(6), 296–302. https://doi.org/10.3109/14764172.2010.538413

USP 29. (2007). USP Monographs:Nonabsorbable surgical suture.

About the Author: Rudra Narayan Saha is a graduate of Govt. College of Engg. & Textile Technology, Berhampore, West Bengal, where he earned his degree in Textile Technology. He also holds a Master's degree in Textile Engineering from GCETTB. Rudra N Saha specialises in the education of weaving and textile testing section. He is currently conducting research at NIT Jalandhar, focusing on advancements in medical textiles.