When a wound requires stitches, choosing the appropriate suture involves more than simply closing the skin. Healthcare professionals consider the tissue being repaired, the location and depth of the wound, how much tension is present and how long the tissue is likely to need support while it heals.
Surgical sutures come in different materials and designs. Some gradually break down in the body, while others remain until they are removed or are intended to stay within the body for longer-term support.
Understanding the different types of surgical stitches and why they are used can help patients better understand wound closure and the healing process.
What Are Surgical Sutures?
Surgical sutures, commonly called stitches, are medical devices used to bring tissue edges together and hold them in place while healing takes place.
They may be used to close wounds caused by injury or to repair tissues during surgery. Sutures can be placed in the skin, deeper tissue layers or internally, depending on what needs to be repaired.
The purpose of suturing may include:
- Bringing tissue edges together
- Keeping tissues in the intended position during healing
- Providing support while the tissue regains strength
- Closing deeper tissue layers as well as the skin
- Helping restore the protective barrier of the skin
Not every wound should necessarily be closed immediately. The decision depends on factors such as the type and location of the wound, how long ago it occurred, the degree of contamination and the patient’s risk of infection or poor wound healing. Some wounds may be closed immediately, while others may require delayed closure or another approach to wound management.
Sutures vs Stitches: Is There a Difference?
The terms sutures and stitches are often used interchangeably.
More precisely, a suture refers to the material used to bring tissue together, while a stitch can refer to an individual placement of that material.
In everyday medical communication, however, patients may hear both terms used to describe the same wound-closure treatment.
How Doctors Choose the Right Suture
There is no single suture that is appropriate for every wound or surgical procedure.
The choice depends on both the tissue being repaired and the characteristics of the suture itself.
Several considerations are important:
The tissue being repaired
Different tissues have different strengths and healing patterns.
Skin, deeper connective tissues and internal organs do not necessarily require the same type of suture or the same length of support.
How long the tissue needs support
This is particularly important when selecting an absorbable suture.
Different absorbable materials retain their strength for different periods before gradually being broken down by the body. A tissue that needs support for only a relatively short period may therefore require a different suture from a tissue that regains strength more slowly.
Tension on the wound
Some wounds are exposed to greater movement or tension than others.
The amount of tension across the tissue can influence the suture material, size and closure technique selected.
Location of the wound
The location of a wound also matters. Sutures used for skin closure may have different requirements from those used deeper within the body.
Location can also affect factors such as movement, tension, exposure and whether stitches will later need to be removed.
Properties of the suture
Sutures differ in characteristics including:
- Material
- Strength
- How long they retain that strength
- Whether and how quickly they are absorbed
- Flexibility
- Surface characteristics
- Handling and knot behaviour
Suture selection therefore involves matching the properties of the material with the requirements of the tissue and procedure.
Types of Surgical Sutures
Sutures can be classified in several ways.
One of the most important distinctions is whether the suture is absorbable or non-absorbable.
They can also be classified by their construction, such as monofilament or braided, and by whether the material is natural or synthetic.
Absorbable Sutures
Absorbable sutures are designed to gradually lose strength and break down within the body.
They are commonly used:
- In deeper layers beneath the skin
- For internal tissues
- Where temporary tissue support is required
- When later stitch removal would be difficult or unnecessary
Common synthetic absorbable suture materials include polydioxanone (PDO), polyglycolic acid (PGA) and polyglactin 910 (PGLA).
Different absorbable sutures behave differently after they are placed.
One important distinction is between how long the suture retains useful strength and how long it takes for the material to be completely absorbed.
These are not necessarily the same.
An absorbable suture gradually loses tensile strength as the material breaks down. Much of its ability to support the tissue may therefore be lost before the suture material itself has been completely absorbed.
The US Food and Drug Administration considers both changes in tensile strength over time and the rate and completion of absorption when evaluating absorbable surgical sutures.
This is one reason different absorbable materials are available: tissues do not all need support for the same length of time.
Absorbable sutures generally do not require routine removal, although individual circumstances vary.
Learn more about our range of absorbable sutures
Non-Absorbable Sutures
Non-absorbable sutures are designed to resist breakdown in the body and can provide longer-term support.
When they are used to close the skin, they are generally removed by a healthcare professional once the wound has healed sufficiently.
Non-absorbable sutures can also be used internally when prolonged or permanent support is required. In these circumstances, the material may remain within the body.
Common non-absorbable materials include:
- Nylon
- Polypropylene
- Polyester
- Silk
- Stainless steel
The choice between absorbable and non-absorbable sutures therefore depends on what is being repaired and how long support is required. Neither type is inherently better than the other.
Learn more about our range of non-absorbable sutures
How Long Does a Suture Need to Support a Wound?
A wound does not immediately regain its normal strength after it has been closed.
Healing takes place over time, and different tissues recover strength at different rates.
Sutures help hold the tissue in the intended position during the period when the healing tissue is not yet strong enough to do so on its own.
For absorbable sutures, this makes strength retention particularly important.
A surgeon can select a suture according to how long the tissue is expected to require support. Some absorbable sutures lose strength relatively quickly, while others are designed to retain support for longer.
This should not be confused with the time required for complete absorption.
For example, a suture may have lost much of its strength while some of the material remains present in the body.
For non-absorbable stitches placed on the skin, the timing of removal is determined by factors including the wound location, tension and how well the wound is healing.
Monofilament vs Braided Sutures
Another important difference between sutures is how the strand itself is constructed.
Monofilament sutures
A monofilament suture consists of a single strand of material.
Its relatively smooth construction allows it to pass through tissue with less surface drag than many braided materials.
Monofilament sutures also have their own handling characteristics. Some can be relatively stiff or have greater memory, meaning the material tends to retain the shape it had in its packaging.
Braided sutures
Braided, or multifilament, sutures are made from multiple fibres woven or twisted together.
This construction gives them different handling and knot characteristics from monofilament sutures.
The spaces between individual fibres also mean that braided and monofilament sutures interact differently with fluids and microorganisms. However, these material characteristics should not be interpreted to mean that one construction universally results in a lower clinical risk of infection.
Wound infection is influenced by many factors, including:
- Degree of wound contamination
- Tissue condition
- Surgical technique
- Patient-related factors
- Wound care
- The type and location of the procedure
The choice between monofilament and braided sutures therefore depends on the clinical requirements rather than a general rule that one is better.
Natural vs Synthetic Sutures
Sutures may also be made from natural or synthetic materials.
Examples of natural suture materials include surgical gut and silk.
Synthetic materials include polydioxanone, polyglactin, polyglycolic acid, polypropylene and nylon.
The source of the material can influence characteristics such as:
- Strength
- Absorption
- Tissue response
- Flexibility
- Handling
- Knot characteristics
Modern surgical practice uses a range of natural and synthetic materials, with the appropriate choice depending on the tissue and procedure.
What Are Knotless Barbed Sutures?
Barbed sutures differ from conventional smooth sutures in their construction.
Small projections, or barbs, along the strand engage the surrounding tissue as the suture is placed. This helps the suture maintain its position and can allow tissue to be closed without conventional knot tying in selected procedures.
Learn more about our barbed sutures
Why are Knotless barbed sutures used in laparoscopic surgery?
Suturing during laparoscopic surgery can be technically demanding because the surgeon is working with instruments passed through small access points rather than directly handling the tissue.
Conventional suturing may also require knots to be tied inside the body, known as intracorporeal knot tying.
Barbed sutures offer a different approach. As the suture is placed, the barbs engage the tissue and help prevent the strand from sliding backwards. This can help maintain tension along the closure without requiring the surgeon to continuously maintain traction on the previous stitch.
The ability to close tissue without conventional knot tying is one reason barbed sutures are used in a range of laparoscopic and other minimally invasive procedures.
Studies have examined whether this affects suturing and operating times.
For example, a 2024 systematic review and meta-analysis of laparoscopic myomectomy found that use of barbed sutures was associated with shorter operative and suturing times compared with conventional sutures in the included studies. The pooled difference was approximately 12 minutes for total operative time and six minutes for suturing time.
These findings should not be interpreted to mean that barbed sutures universally shorten every operation or are preferable for every type of closure. Results depend on the procedure, technique and clinical circumstances.
The choice between barbed and conventional sutures therefore depends on factors such as:
- The procedure being performed
- The tissue being repaired
- The closure required
- Surgical technique
- Surgeon experience and preference
Barbed sutures are another suture design available for selected applications rather than a replacement for conventional sutures in all procedures.
How Do Sutures Support Wound Healing?
Sutures help create the conditions for a wound to heal, but the suture itself does not heal the tissue.
Healing is carried out by the body’s biological processes.
After an injury or surgical incision, the body begins a series of overlapping responses that control bleeding, manage inflammation, form new tissue and gradually remodel that tissue.
During the early stages of this process, the repaired tissue has limited strength.
Sutures help keep the tissue edges together during this period while new tissue forms and gradually becomes stronger.
This is another reason suture selection matters. Ideally, the suture provides the level and duration of support appropriate for the tissue while healing progresses.
Other factors can also affect wound healing, including:
- The type and extent of the wound
- Blood supply to the tissue
- Infection
- Tissue tension
- Patient health
- Smoking
- Certain medical conditions and medications
- Post-procedure wound care
Sutures are therefore one part of wound management rather than the sole factor determining how a wound heals. Not every wound requires stitches; depending on the wound and clinical circumstances, healthcare professionals may use other closure methods or may decide that immediate closure is not appropriate.
Caring for a Sutured Wound
After a wound has been sutured, patients should follow the wound-care instructions provided by their healthcare team.
Instructions vary according to the wound, procedure and type of dressing used, so there is no single dressing-change schedule that applies to every sutured wound.
In general, patients may be advised to keep the wound clean and protected and to replace a dressing if it becomes wet, dirty or loose, unless different instructions have been provided.
Patients should seek medical advice if they develop symptoms such as:
- Increasing redness or swelling
- Increasing pain
- Pus or other concerning discharge
- Fever
- Spreading redness around the wound
- Persistent bleeding
- Opening of the wound
Stitches should not normally be removed by the patient unless specifically instructed to do so by a healthcare professional.
Understanding Why Different Types of Surgical Stitches Are Used
Different tissues and wounds have different requirements during healing. When selecting a suture, surgeons consider factors such as the tissue being repaired, tension across the wound, how long support is needed and the characteristics of the suture material.
This is why there is no single “best” type of suture. Absorbable, non-absorbable, monofilament, braided and barbed sutures each have characteristics that may make them appropriate for different tissues, procedures and clinical situations.
Selecting the appropriate suture involves matching these characteristics with the needs of the tissue and the requirements of the procedure.
References
US Food and Drug Administration (FDA). Surgical Sutures — Class II Special Controls Guidance Document for Industry and FDA Staff. Guidance addressing surgical suture materials, physical and performance characteristics, tensile strength and absorption characteristics.
US Food and Drug Administration (FDA). Surgical Sutures — Performance Criteria for Safety and Performance Based Pathway. Guidance addressing performance evaluation of surgical sutures, including tensile strength and absorption characteristics of absorbable sutures.
Merck Manual Professional Edition. Skin Lacerations. Clinical guidance addressing wound assessment, primary and delayed wound closure, contamination and factors affecting the decision to close a wound.
Barbed Sutures Compared With Conventional Sutures During Laparoscopic Myomectomy: A Systematic Review and Meta-analysis. Review examining perioperative outcomes associated with barbed and conventional sutures in laparoscopic myomectomy.
This article is intended for general educational purposes and does not replace individual medical advice, diagnosis or treatment from a qualified healthcare professional.