Suture Selection Guide: Tips for Surgical Procedures

A crucial aspect of successful surgical procedures lies in the surgeon's ability to understand and select the appropriate suture types. This entails differentiating between various sutures available and comprehending how the unique characteristics of needles and threads impact their performance.

For surgeons, the array of surgical sutures can be daunting. This guide aims to simplify the selection process by elucidating the rationale behind suture choice and discussing the advantages and limitations of each type. However, it's vital to acknowledge that the availability of specific sutures may vary by location, thus influencing the tools accessible to surgeons.

Surgical procedures is the surgeon's ability to select appropriate sutures that minimize tissue damage and promote healing. Sharp dissection techniques are preferred over blunt methods as they reduce trauma to tissues. Proper suture selection ensures wound edges are closely approximated without undue tension, facilitating faster healing. While there's no universal perfect stitch, understanding the characteristics of different sutures helps surgeons choose the most suitable option for each procedure.

Basics of Sutures:

Sutures are broadly classified into absorbable and non-absorbable materials, with further subdivisions into synthetic or natural and monofilament or multifilament sutures. The ideal suture is the smallest size capable of providing uniform tensile strength, securely holding the wound for the necessary healing period, and then being absorbed. It should be predictable, easy to handle, elicit minimal reaction, and securely knot.

Absorbable sutures:

Absorbable sutures like catgut are designed to be absorbed by the body's tissues over time, eliminating the need for removal after healing. Catgut is traditionally sourced from the submucosal layer of sheep intestines or the serosal layer of beef intestines. It's available in two main types: plain and chromic. Plain catgut is untreated and absorbed more rapidly, suitable for shorter-term healing. Chromic catgut undergoes a chromic salt treatment process, enhancing its tensile strength and slowing down absorption, making it ideal for longer-term wound closure. These properties make catgut a versatile choice in surgical settings where absorbable sutures are needed.

• Plain catgut: It loses half its strength in 10-14 days and all its effective strength in 21 days. Complete absorption occurs within 30-50 days.
• Chromic catgut: It loses half its strength in 11-14 days and all its effective strength in 28 days. Complete absorption occurs within 45-90 days.

Non-absorbable sutures:

Non-absorbable sutures are made from materials that are not intended to be absorbed by the body's tissues and thus require removal after the wound has healed. These materials include silk, polyester (such as Dacron), polypropylene (such as Prolene), and stainless steel.

• Silk: Silk sutures are natural fibers derived from silkworm cocoons. They are known for their smooth texture, flexibility, and ease of handling. Silk sutures are commonly used in skin closure and delicate tissues due to their tie-ability and minimal tissue reaction.
• Polyester (Dacron): Polyester sutures are synthetic fibers known for their strength, durability, and resistance to degradation by tissue enzymes. They are often used in cardiovascular surgeries, where long-term strength is crucial.
• Polypropylene (Prolene): Polypropylene sutures are another synthetic option known for their inertness and biocompatibility. They are resistant to infection and tissue reactions, making them suitable for various surgical procedures, including ophthalmic and orthopedic surgeries.
• Stainless Steel: Stainless steel sutures are used in specialized situations where long-term support or non-reactive material is needed, such as in cardiovascular or orthopedic surgeries. They provide excellent tensile strength but are rarely used due to the availability of more modern synthetic alternatives.

Selecting the Size of Suture Material:

• If the suture used for wound closure is too thick, wound healing can be delayed.
• Suture materials are gauged using metric figures, with size 0.1 being the finest and 9 metrics being the thickest.

Clinical application of different sutures:

Tissue	Type of Suture
Ligature	Catgut - coated vicryl silk - mersilk
Skin	Ethilon Prolene Mersilk
Subcuticular	Coated Vicryl
Muscle	Coated Vicryl
Stomach/Bowel	Coated Vicryl
Tendons	Prolene
Cornea	Ethilon
Nerves	Ethilon

Factors to consider in Suture Selection:

Tissue Type: 

Different tissues require specific suture materials. Delicate tissues, like the liver or blood vessels, may benefit from finer and more flexible sutures, while denser tissues like tendons may require stronger and more substantial sutures.

Duration of Support:

Consider the duration for which the suture material needs to provide support. Absorbable sutures are suitable for tissues needing temporary support, while non-absorbable sutures are ideal for structures requiring extended or permanent reinforcement.

Infection Risk:

The risk of infection is a crucial consideration. Monofilament sutures, with their smooth surface, minimize bacterial harbourage, reducing the risk of postoperative infections. Multifilament sutures, though offering flexibility, may pose a slightly higher infection risk.

Allergies and Sensitivities:

Patient-specific factors such as allergies or sensitivities should be considered. Selecting a suture material that minimizes the risk of adverse reactions is essential for individuals prone to such issues.

Selection based on Surgical Procedures:

General Surgery:

Versatile synthetic sutures like polydioxanone (PDO) or polyglactin are commonly used in general surgery procedures due to their adaptability.

 Cardiovascular Surgery:

Non-absorbable, high-tensile strength sutures such as polypropylene or polyester are often required for cardiovascular procedures.

Orthopaedic Surgery:

Orthopaedic surgeries, involving dense and load-bearing tissues, may necessitate robust non-absorbable materials like stainless steel wire or polyethylene sutures.

Dermatological Procedures:

Dermatological interventions often utilize finer, more cosmetic-friendly sutures like monofilament nylon or polypropylene.

Choosing the right surgical suture material is crucial for optimal patient outcomes. Surgeons consider tissue type, duration of support needed, infection risk, and patient-specific factors to make informed decisions, ultimately contributing to successful surgical interventions.

Selecting the surgical needles for suturing:

Needle Types:

• Round-bodied: Designed to separate tissue fibers rather than cut, typically used for soft tissue cardiovascular or intestinal surgery.
• Conventional cutting: Features cutting edges restricted to the front section of the needle, with a cross-section and three cutting edges.
• Reverse cutting: Resistant to bending, reduces the tendency for the suture to be pulled through the tissue.
• Trocar point: Features a strong cutting head for powerful penetration, especially in dense tissue.
• Taper cut: Combines the initial penetration characteristics of a cutting needle with those of a round-bodied needle.

Needle Shape: 

Curved suture needles are commonly used for most applications. The curvature of the needle depends on the accessibility of the tissue to be sutured. The more confined the operative site, the greater the curvature required.

Needle Strength: 

The diameter of the wire from which the needle is manufactured is a major factor in determining its strength. It's essential to ensure that the force applied to the needle does not exceed its designed capacity. The needle should bend rather than break. If bending occurs, it indicates that the critical point has been surpassed, and the needle should be discarded instead of attempting to straighten it.

Use of Needle Holders: 

Select a needle holder carefully to match the size of the needle used. Hold needles on a flatted area, avoiding contact with the needle point or attachment area.