The Primary Classifications of Surgical Sutures
When a surgeon selects a suture, their decision is based on a careful analysis of the patient, the wound, and the surgical site. The most fundamental division of suture materials is into two broad categories: absorbable and non-absorbable.
Absorbable Sutures
Absorbable sutures are designed to lose their tensile strength and be broken down by the body over a predictable period. The absorption process typically involves hydrolysis, which minimizes tissue reaction compared to the enzymatic digestion of older materials. This eliminates the need for a secondary procedure for suture removal, making them ideal for internal stitches.
- Polydioxanone (PDS): A synthetic monofilament suture with a long absorption time, making it suitable for slow-healing tissues like fascia closures in the abdomen or pediatric cardiac surgery. Its monofilament nature means less risk of infection.
- Poliglecaprone (MONOCRYL): A synthetic monofilament that loses strength quickly and is absorbed relatively fast. It is known for its excellent handling and low tissue reactivity, making it a good choice for cosmetic skin closures.
- Polyglactin 910 (Vicryl): A synthetic braided multifilament suture known for its strength and predictability. It is commonly used for general soft tissue approximation and ligation, though its braided nature can increase infection risk in contaminated wounds.
- Chromic and Plain Gut: These are natural, multifilament sutures made from purified collagen. They have a more significant tissue reaction and less predictable absorption rate. Modern synthetic alternatives are often preferred, but gut is still used in some mucosal or internal ligation applications.
Non-Absorbable Sutures
Non-absorbable sutures are made of materials that the body cannot digest. These sutures provide long-term tissue support and are either removed after the wound has healed or are left permanently inside the body, where they become walled off by the body's inflammatory response.
- Nylon (Ethilon): A synthetic monofilament suture with high tensile strength and minimal tissue reaction. It is a very common choice for skin closure and microsurgery.
- Polypropylene (Prolene): A synthetic monofilament known for its smoothness and low tissue reactivity. It is the gold standard for cardiovascular and vascular surgery due to its permanence and inert nature.
- Polyester (Ethibond): A synthetic braided multifilament suture with high strength and low tissue reactivity, often coated to improve handling. It is used in orthopedic surgery, such as tendon repair, and for attaching prosthetic materials.
- Silk: A natural, braided multifilament suture highly prized for its excellent handling and knot security. Despite causing more tissue reaction than synthetics and being technically non-absorbable, its strength degrades over time. Today, it is primarily used for securing drains or for temporary closures.
Monofilament vs. Multifilament: The Suture Structure
Beyond absorbability, sutures are also categorized by their physical structure, a factor that significantly impacts their performance.
- Monofilament: A single-strand suture. It slides through tissue smoothly with minimal drag, reducing tissue trauma and the risk of infection. However, monofilaments can have poor knot security and memory (a tendency to retain their packaging shape), making them harder to handle.
- Multifilament: Composed of multiple braided or twisted strands. These sutures are flexible, have excellent knot security, and are easier for surgeons to handle. The trade-off is greater friction as they pass through tissue and a higher potential for bacteria to harbor in the braids, increasing infection risk.
Comparison of Absorbable and Non-Absorbable Sutures
| Feature | Absorbable Sutures | Non-Absorbable Sutures |
|---|---|---|
| Breakdown | Broken down by the body via hydrolysis or enzymes. | Retain tensile strength indefinitely; must be removed or left permanently. |
| Best Used For | Internal closures where removal is not possible or practical. | Skin, tendons, and high-tension areas requiring long-term support. |
| Example Uses | Subcutaneous layers, fascia, mucosal tissues. | Skin closure, vascular anastomosis, orthopedic repairs. |
| Removal | No removal needed; dissolve naturally. | Manual removal often required for external stitches. |
| Tissue Reaction | Can cause more initial inflammation, especially natural types. | Generally cause minimal tissue reaction over the long term. |
How Surgeons Select the Right Suture
Choosing the correct suture is a critical step in any surgical procedure. The decision-making process involves several key considerations:
- Tissue Characteristics: The type of tissue being repaired is paramount. Fast-healing tissue like the stomach lining may require a rapidly dissolving suture, while slow-healing tissue like fascia or tendons needs prolonged support from a non-absorbable or slow-absorbing material.
- Wound Tension: Wounds under high tension, such as those on the abdomen, require stronger sutures with high tensile strength. Low-tension wounds, like facial lacerations, prioritize minimal scarring over maximum strength.
- Infection Risk: In areas with a high risk of contamination or infection, a monofilament suture is generally preferred over a multifilament one, as the single strand provides fewer places for bacteria to accumulate.
- Patient Factors: The patient's age, comorbidities, and overall health can influence the choice. For instance, a child's facial laceration might use a fast-absorbing gut to avoid a second procedure.
- Cosmetic Outcome: For visible areas like the face, a monofilament suture that causes less tissue reaction and can be placed subcuticularly is chosen to minimize scarring.
Advanced Suture Technologies
Modern surgical innovation has led to specialized sutures that offer distinct advantages:
- Barbed Sutures: These sutures have microscopic barbs along their length that anchor into the tissue without needing knots. They save time and distribute tension more evenly along the wound line.
- Antibacterial Sutures: Some sutures are coated with antimicrobial agents, such as triclosan, to reduce the risk of surgical site infections, a critical concern in many procedures.
Ultimately, the science and art of surgery involve a careful, deliberate choice of materials. The vast array of sutures available today allows surgeons to tailor their approach to each unique situation, optimizing patient recovery and outcomes. For a deeper understanding of surgical procedures and techniques, it's beneficial to consult reputable medical resources, such as those found on the official site of the American College of Surgeons.
Conclusion
The question, "What type of suture is used in surgery?" has no single answer because the perfect suture depends on the surgical context. The fundamental classifications—absorbable versus non-absorbable and monofilament versus multifilament—provide the framework for this critical decision. By considering factors like tissue type, healing time, and infection risk, surgeons can select the appropriate material and technique to ensure optimal healing, minimize complications, and achieve the best possible patient outcome.
