Suture Materials: Types of Suture Thread & How to Choose

1. What Is a Suture Thread?

A suture thread is a medical material used to stitch and hold tissues together after a wound, surgery, or incision. Its main purpose is to support the healing process by keeping the wound edges aligned, minimizing bleeding, and reducing the risk of infection. A complete suture usually includes a sterile thread and a curved surgical needle.

The type of thread used can vary depending on the location of the wound, the healing time needed, and how deep the tissue is. For students and beginners learning to suture, getting familiar with different suture threads is an essential first step before practicing real techniques.

2. Types of Suture Threads by Material

Suture threads are often categorized based on how the body reacts to them. The two main types are:

2.1 Absorbable Sutures

These sutures are broken down and absorbed by the body over time, usually within a few weeks or months. They are often used for:

A. Internal tissues, such as:

• Muscle layers beneath the skin
• Fascia (the connective tissue surrounding muscles)
• Subcutaneous fat (the layer just under the skin)
• Organs like the intestines or bladder

B. Deep layers that don’t require follow-up removal, meaning the sutures dissolve on their own and don’t need to be taken out after healing. For example:

• Closing surgical incisions inside the abdomen
• Repairing tears in internal organs during surgery
• Suturing blood vessels or ducts inside the body

Common materials:

• Polyglycolic Acid (PGA)
• Polyglactin 910 (PGLA)
• Catgut (natural, used less today)

2.2 Non-Absorbable Sutures

These sutures do not dissolve naturally and need to be removed manually once the tissue has healed. They are commonly used for:

A. Skin closures, such as:

• Closing cuts or lacerations on arms, legs, or torso
• Suturing surgical incisions on the skin surface
• Repairing wounds after trauma or accidents

B. Long-term support in high-tension areas, where strong, durable support is needed during healing, such as:

• Tendon repairs (e.g., hand or wrist tendons)
• Ligament reconstructions
• Certain cardiovascular surgeries where sutures need to hold vessels firmly
• Fascia closure in areas of the abdomen under tension

Common materials:

• Nylon
• Silk
• Polypropylene (Prolene)

3. Common Suture Thread Materials Explained

Here is a comparison of common suture materials and their typical characteristics:

4. Understanding Suture Sizes (USP)

Sutures come in different thicknesses, indicated by the United States Pharmacopeia (USP) sizing system. The size affects the suture’s strength and suitability for various tissues.

• Sizes appear as numbers like 2/0, 3/0, 4/0, or whole numbers like 1, 0, 2.
• More zeros mean thinner thread: for example, 2/0 (two-ought) is thicker than 3/0 (three-ought).
• Thicker sutures (e.g., 1, 0, 2) provide greater strength for heavy or deep tissues.
• Thinner sutures (e.g., 5/0, 6/0) are used for delicate tissues needing minimal scarring.

Examples:

• 1 or 2/0 sutures: used for closing fascia, muscle, or heavy tissue.
• 3/0 or 4/0 sutures: general skin closure.
• 5/0 or 6/0 sutures: cosmetic or delicate areas such as face, hands, or blood vessels.

5. How to Choose the Right Suture Thread?

Here are key questions to consider when choosing sutures:

5.1 What tissue are you suturing?

• Use absorbable sutures for internal layers (muscle, fascia, organs).
• Use non-absorbable sutures for skin or tissues needing strong long-term support.

5.2 Will the sutures need to be removed?

• If yes (usually for skin), use non-absorbable.
• If no, or if internal, use absorbable.

5.3 How easy is the thread to handle?

• Silk and braided PGA are easier for beginners.
• Monofilament nylon or polypropylene may require more practice.

5.4 What suture size fits best?

• Thicker sutures for strong tissues, thinner for delicate areas.

6. Recommended for Practice

If you’re a beginner or medical student, you’ve probably faced questions like:

• “Which suture thread should I start with?”
• “Why do some threads feel so different to handle?”
• “How do I know if I’m tying knots correctly with different materials?”

This is normal! hese are common challenges when learning suturing. Using a mixed suture thread with needle kit helps you practice with various threads and sizes. It lets you feel the differences, learn knotting techniques, and build confidence.

7. Conclusion

Understanding suture types, materials, and sizes is fundamental to developing suturing skills. Whether practicing or preparing for clinical work, knowing how to select the right thread for each tissue and situation helps ensure successful wound healing and better patient outcomes.