Non-absorbable sutures are a type of material used in surgery. They are intended to stay in the body and not be degraded through chemical means. Absorbable sutures are used in surgery and wound healing, breaking down and assimilating them over time. Depending on the surgery, non-absorbable sutures could remain in the body permanently, or they could be self-absorbent and require removal after a particular time.

Non-absorbable sutures are essential in certain surgeries where the wound should not be permanently closed. This is especially important in cardiovascular or orthopedic surgeries where mechanical stress is constant or healing takes longer. They provide strength and stability, thus holding together tissues during healing. Due to the ability of the preferred materials, they are helpful where high-tension areas are present in the application, and tissue separation issues may cause harm.

Some popular uses of non-absorbable sutures include skin closure procedures, cardiovascular surgeries, and surgical operations on the bones. They are also used for patients requiring long-term tissue approximation or when suture removal is possible after healing. It is, therefore, crucial that the right suture material is used to avoid compromising the result of surgery, taking the time to heal, and increasing the complication rate.

What Are Non-Absorbable Sutures?

Non-absorbable sutures are a category of surgical suture material that is not metabolized and remains within the tissues. They are not metabolized and are left behind to support the tissue for long-term healing. These sutures remain in the body, primarily when used internally, or are occasionally removed when the external wound has healed well. For this reason, non-absorbable sutures are beneficial in cases where prolonged or permanent support is required to recover the wound.

The long-term use of non-absorbable sutures in wound closures is essential, as the tissue can stick tightly together, thus reducing the chances of wound dehiscence. Sometimes, for instance, in cardiovascular surgeries, non-absorbable sutures close important vessels or tissues under which lasting reinforcement is utilized to restore the correct functioning of the organ. Likewise, these suture materials might be used in orthopedic surgeries to repair tendons, ligaments, or bones that need secure and long-lasting closure.

Non-absorbable sutures are used in several surgical operations Some of them are as follows: In cardiovascular surgery, they sew blood vessels, grafts, and heart tissues, which demand reinforcement for a longer duration. In orthopedic surgical procedures, they are crucial as those parts of the body that need strength and endurance consist of tendons, ligaments, and bones. On the other hand, non-absorbable sutures can be applied whenever skin closure is required on external wounds that need a longer duration of support, especially in areas highly susceptible to motion or stress. These sutures are also used for facial cosmetic surgery, ophthalmological surgery, other operations, and dental surgery, where strength and durability are required to have tissue-holding capacity for a long time.

Types of Non Absorbable Sutures

Non-absorptive sutures can be classified as tangible, fake, natural, and synthetic. Each type also has specific characteristics that provide particular surgeries following the sutured tissues, the required integrity, and patients’ reactions. Therefore, emphasis should be placed on the differences between these sutures to achieve optimal wound-healing results in the long run.

Natural Non Absorbable Sutures

The best-known example is silk sutures produced from silkworm fibers. These sutures are braided and hence have good handling and knot-tying properties. Sutures made of silk are virtually knotless and very flexible, and therefore, they are the best type of suture for working in sensitive areas where accuracy and precision are paramount. However, silk elicited a higher inflammatory response in some patients than synthetic material. It may be non-absorbable, but the material's tensile strength may reduce over time.

These types of sutures are applied where an accurate approximation of tissues has to be obtained; tissue strength is not paramount but rather tissue pliability and ease of use. Their popularity has, however, reduced in recent years, with synthetic products being more common, especially where long-term systemic support is needed or in sensitive patients.

Synthetic Non-Absorbable Sutures

Synthetic, non-absorbable sutures are made from man-made materials that offer higher durability, minimal tissue reaction, and consistent long-term strength. Some of the most common types include:

Nylon (Polyamide) Sutures: It is commonly used in skin closures because it’s smooth and reduces tissue damage while passing through. Although its knot security is comparatively lower than that of braided sutures, its strength and wear-resistant factor make it suitable for exterior skin use. Nylon is elected where there is a need to cause the slightest injury depending on the type of surgery, such as cosmetic or pediatric surgeries.

Polypropylene Sutures: Polypropylene is a synthetic monofilament suture with high tensile strength, flexibility, and few tissue reactions. It is one of the most biocompatible non-reactive materials. It can be used in cardiovascular and vascular surgeries, where firm support of the tissues is needed for a long time without inflammation. Polypropylene sutures are non-elastic and do not stretch or snap; hence, they keep the tissue approximation very strong, even in tension zones. They are also preferred, regardless of surgery, due to their capacity to create low scar tissue formation.

Polyester Sutures: To minimize the coefficient of friction, they are either braided or coated on polyester sutures with silicone or even polytetra fluoro ethylene (PTFE). One of the advantages is that they afford high tensile strength, which is preferred in areas of strain like orthopedic & cardiovascular operations. They appear braided, which gives them good knot security, essential in ensuring the sutures remain in place when healing occurs. Polyester suture materials are mainly employed in those surgical operations where the strength and the dependability of the suture are essential such as in the repair of tendons or ligaments.

Stainless Steel Sutures: Non-absorbable sutures are stronger than absorbable sutures, and the stainless steel type is the strongest; it is used in operations that need a lot of tensile strength, as in surgery of fracture bones or in thoracic surgery to close the sternum. These sutures are very resistant to infection and corrosion hence they can be used for long-term implantation. Nonetheless, the stainless steel sutures are not as flexible and require a lot of skill when placed compared to the rest of the materials.

Characteristics of Non-Absorbable Sutures

Each type of non-absorbable suture has distinct characteristics that make it suitable for specific applications. These characteristics include:

Tensile Strength: Considering that the strength with which a suture resists tension is more important in a stressed region such as the heart, tendons, or even bones is essential. Materials such as PP(polypropylene) and 304L SS (stainless steel) have high tensile strength, keeping the wound closed under high stress.

Flexibility: Silk and polyester sutures are more flexible than other materials, making them easier to handle when tying knots. The researchers postulated that this is vital in sensitive or complex processes when rigid material may pose a problem or even lead to tissue injury.

Knot Security: The holds that a suture imparts on a knot are vital in the integrity of the tissue approximation to hold until the healing process is complete. Silk and polyester sutures, which are braided, have suitable knot control compared to nylon and polypropylene, which are monofilaments and may need an extra three or four knots to hold the knot securely. Knot security applies mainly in operations where high-tension tissues are expected, such as surgery involving joints or the heart.

Non-Absorbable Sutures Examples

Non-absorbable sutures are available in various materials, each designed to meet specific surgical needs based on the type of tissue, the required durability, and the potential for tissue reaction. Here are key examples of commonly used non-absorbable sutures:

Silk Sutures

Silk sutures are absorbent, non-woven sutures made from pure silk, which the Silkworms produce. They have very high handling characteristics and are perhaps by far some of the most accessible materials to handle, especially during operations that call for a lot of precision. Silk sutures have a braided structure, which offers good flexibility and knot security so that the suture does not come off. Nevertheless, silk sutures evoke a more robust inflammatory response than synthetic suture materials, and their mechanical properties decrease with time while they do not dissolve entirely.

Uses: Silk sutures are generally employed in soft tissue surgery, most predominantly in situations where delicate tissue handling is required, such as ophthalmological, gastrointestinal, and cardiogenic ones.

Nylon (Polyamide) Sutures

Nylon is a synthetic, non-laced monofilament with high shear strength and low tissue reactivity. The protracted, non-locking monofilament structure minimizes the bacteria-depositing surfaces and the degree of tissue irritation while passing through. While nylon sutures provide relatively high tensile strength, the knot security is slightly lower than in braided sutures; therefore, several knots are required to achieve proper anchorage. They are essential in external closures where long-term tissue support is less imperative.

Uses: Nylon sutures, including cosmetic and pediatric surgeries, can be non-absorbable for skin closure procedures. Nylon’s smooth texture does not efficiently remodify skin scars.

Polypropylene Sutures

Polypropylene sutures are another synthetic monofilament. However, they are considered non-reactive and have significant tensile strength. This suture material does not easily break and stretch; hence, it can be recommended for parts of the body that experience movement or tension. Non-absorbable sutures, including those made from polypropylene, are the least reactive to tissues, posing little risk of creating an inflammatory or immune response; thus, they are useful for sensitive or chronic tissue closure surgeries. Their tall knot security guarantees the sutures remain adequately fixed in the areas more often subjected to tension.

Uses: Polypropylene sutures are the most common surgical sutures. They are used in cardiovascular surgery, including vascular grafting and plastic surgeries, which require permanent and robust support that will not result in skin scarring.

Polyester Sutures

Polyester sutures are synthetic and braided; generally, they are coated to minimize friction and facilitate easy handling. These are appreciated for having the best tensile strength and applied in areas where tissues are stretched. The construction of the sutures in braid form gives the knotting system excellent security as the knot stays in place than could be expected in testing situations. Polyester sutures are married and have good tensile strength, so they’re always used both for stitches inside the body and those outside any areas that will move or are chronically strained.

Uses: Monofilament sutures, such as polyester sutures, are ideal for muscle and tendon or ligament repairs and cardiovascular surgeries since they require long-term tissue approximation.

Stainless Steel Sutures

Stainless steel sutures are the strongest and most permanent of all non-absorbable sutures and hence are very useful in surgeries that require high tensile strength. These sutures are anti-corrosive, anti-infection, and slow to degrade, thereby being useful in long-term implantation. However, whereas it is easier to handle and tie into knots, they are rigid compared to flexible material. Nonetheless, sutures made from stainless steel offer tremendous tensile strength and are suitable for operations where proper alignment of tissues is mandatory for correct healing.

Uses: In this particular type of surgery, stainless steel sutures are primarily applied in Orthopedic surgeries to suture bones and thoracic surgeries, particularly to suture the sternum after open heart operations. They are also used in dentistry, specifically in fixing dental implants to the jaw bone.

Benefits and Limitations of Non-Absorbable Sutures

Due to their unique properties, non-absorbable sutures are widely used in various surgical procedures. They offer advantages and challenges in different clinical scenarios. Understanding the benefits and limitations of these sutures helps make informed decisions about their appropriate use in wound closure and tissue repair.

Benefits of Non-Absorbable Sutures

• Another benefit derived from using non-absorbable sutures is that they give long-term strength and support to the tissues. In contrast to the absorbable sutures used in body tissues, where sutures degrade with time, non-absorbable sutures maintain their tensile strength into perpetuity. Thus, They are suitable for surgeries where tissue approximation is required for a long time. It is vital in high-stress situations like tendons, ligaments, or cardiovascular structures where the tissue may take years to regenerate fully.

• Immune responses to non-absorbable sutures are expected as they stay in the body for a long time, and as such, they are fashioned from materials that do not degrade in the body. Such resistance to degradation helps preserve the mechanical properties of the suture and, therefore, provides adequate support to the wound or the site that has been operated on. Fibers like nylon, polypropylene, polyester, and metals like stainless steel are very cohesive and capable of withstanding any environmental harshness, such as moisture content or variation in temperature inside the human body. This characteristic makes these sutures suitable for long-term implants of orthopedic cardiovascular operations.

• The strength and largely non-absorbable nature of non-absorbable sutures make them useful in many surgical specializations. They are used in cardiovascular, orthopedic, plastic, and general surgeries and can be used in any position. Many types of sutures, like monofilaments or braided sutures, give the surgeon flexibility that matches the tissues or the wound. For instance, polypropylene sutures are used in cardiovascular surgeries because of their strength and elasticity, and silk sutures are chosen due to their ease of handling in delicate operations.

Limitations of Non-Absorbable Sutures

• The adverse effect of non-absorbable sutures is one of the significant disadvantages of non-absorbable sutures, which is their susceptibility to infection. As these sutures stay within the human body for a long time, they can also become a source of bacterial infection by acting as a foreign body. Surgical silk sutures or polyether glycol sutures and other braided sutures, more particularly, are known to support bacterial growth in the fibers of the sutures hence potentially having greater chances of causing infection if the site of the suture is open or if the environment for surgery is not very sterile like in major surgeries. Surgeons may incorporate anti-microbial sutures or monofilament to reduce this risk since the latter does not hold bacteria.

• Removal may be necessary in other situations, such as non-absorbable sutures, which may require removal in certain surgeries, especially in skin closures once the wound has healed. This is inconvenient for patients and doubles the work that must be done after the operation. The removal procedure also has problems with the risk of infection, reopening of the wound, or reinjury of the tissues where the suture has been placed for a long time or where the tissues are healed tightly around the suture. This is why non-absorbable sutures are usually used internally or where there is no necessity for their removal.

• Risk of foreign body response although non-absorbable sutures do not dissolve in the body and are intended to remain in tissues for a long time, they cause almost no tissue reactions; however, occasionally, the body will react to them as foreign bodies and develop inflammation around them. This reaction ranges from simple inflammation with erythema to more complicated reactions such as the formation of granuloma, where the body forms a scar around the suture material to isolate it. Since silk sutures are a biological material, they are used less often and are more likely to produce such reactions than synthetic materials such as polypropylene or nylon. Hence, immune-sensitive patients can develop issues like complications with foreign body reactions or have to undergo removal earlier.

Conclusion

Non-absorbable sutures have great significance in many surgical operations and findings because of their effectiveness and efficiency in offering long-term support to tissues against degradation factors. These sutures are required in locations where hemostasis is needed or where wound closure has to be permanent or for longer intervals, such as in cardiovascular, orthopedic, and plastic surgery. There are two groups of non-absorbable sutures: natural and synthetics, the majority of which comprise silk, nylon, and polypropylene, all of which present attributes in terms of tensile strength, flexibility, and knot-holding power that render them capable of satisfying specific surgical requirements. However, they have some drawbacks, like the risk of infection, foreign body reaction, and the possibility of removal, pointing out that limitations must be understood.

Selecting the proper, non-absorbable sutures is crucial in the patient’s healing journey.

Proper, non-absorbable sutures are necessary for wound healing and further patient outcomes. Therefore, surgeons need to consider some aspects, namely the type of procedure, the tissue to be used, and the particular characteristics of the specific patient, especially if the person is likely to suffer inflammation or have an infection. Understanding the pros and cons of these sutures enables surgeons, nurses, and other healthcare providers to use sutures that will offer adequate support during the healing process and decrease complications after surgeries.