What Is a Suture?

A suture is a strand of material — natural or synthetic, absorbable or permanent — used to hold the edges of a wound or surgical incision together while the underlying tissue heals. In plain terms, a suture is what most people mean by “stitches”: a needle carries the strand through tissue on either side of the wound, and the strand is tied or otherwise secured to keep the gap closed under the normal stress of movement and healing. Sutures exist because tissue left open, or closed only loosely, heals slower, scars more, and is far more vulnerable to infection and reopening than tissue held in controlled, even apposition from the start.

Where to source this: LAC (lac.us), CASRAI’s sister medical-supply business, stocks sutures directly — browse LAC’s Sutures category to see current products and availability. This is a real, first-party sourcing option under the same operator as CASRAI, not a paid placement or a third-party affiliate link — check any sourcing option against your own facility’s purchasing and vendor-credentialing policy before ordering.

Who uses sutures, and where

Sutures are a fixture of any setting where tissue gets deliberately or accidentally opened and needs a controlled closure: operating rooms, emergency departments and urgent care, outpatient procedure and dermatology clinics, dental and oral surgery practices, and veterinary medicine. A scalpel is frequently the instrument on the other side of this relationship — it makes the controlled incision that a suture later closes — so the two are commonly stocked, taught, and procured together as a pair in surgical and procedural supply planning.

Main types of suture material

Suture products are generally described along three independent axes. A given product is a combination of all three — for example, a braided synthetic absorbable suture, or a monofilament synthetic non-absorbable suture — rather than falling into just one category.

• Absorbable vs. non-absorbable. Absorbable sutures are broken down and cleared by the body over time (through enzymatic action or hydrolysis, depending on the material) and don’t need to be removed — they’re the standard choice for internal tissue layers and for many skin closures where the goal is to avoid a removal visit. Non-absorbable sutures retain their tensile strength indefinitely; they’re used where prolonged or permanent mechanical support is needed, or on skin where the clinician plans to remove them once the wound has healed enough on its own.
• Natural vs. synthetic. Natural sutures are made from processed biological material — for example, surgical gut (historically called “catgut,” despite the name, it’s derived from purified collagen in the intestinal submucosa of sheep or cattle, not from cats) or silk. Synthetic sutures are made from manufactured polymers. Synthetic materials dominate contemporary practice because their absorption rate, tensile-strength loss over time, and tissue-reactivity profile are far more consistent and predictable batch to batch than natural materials.
• Braided (multifilament) vs. monofilament. Braided sutures are made of multiple fine filaments twisted or braided into one strand — this generally gives more flexibility and more reliable knot security, but the braided surface has more texture and capillarity, which can matter for infection risk in contaminated wounds. Monofilament sutures are a single continuous strand — smoother passage through tissue and a lower-friction surface, at the tradeoff of being generally stiffer to handle and sometimes requiring more care to secure a knot that won’t slip.

How suture sizing works

Suture diameter is described using a standardized numeric sizing convention (the U.S. Pharmacopeia, or USP, system is the one most commonly referenced in the United States), where the scale runs from heavier, thicker strands down through progressively finer ones, with finer sizes conventionally denoted by an increasing number of zeros. The right size for a given closure is a clinical decision, not a fixed lookup: a surgeon selects it based on the tissue being closed, the tension the closure needs to withstand, and the cosmetic and healing priorities for that specific case, all governed by the surgeon’s training and the facility’s own procedural protocols. This page describes the sizing convention at that general level rather than asserting which specific size applies to which specific procedure, since that mapping is a clinical judgment that varies by case and by institution.

How a suture differs from adjacent wound-closure options

“Wound closure” is a broader category than sutures alone, and the differences matter for anyone specifying, teaching, or procuring this equipment:

• Sutures vs. surgical staples. Staples close skin (not deeper tissue layers) faster than hand-suturing and are common in long linear incisions such as orthopedic and some abdominal closures, but they don’t offer the same fine control over tissue apposition that sutures do and are generally reserved for skin rather than for closing internal tissue layers.
• Sutures vs. surgical adhesive (tissue glue). Cyanoacrylate-based skin adhesives can close short, low-tension, clean lacerations without a needle at all, but they’re limited to superficial, low-tension wounds — they aren’t a substitute for suturing a deeper or higher-tension closure.
• Sutures vs. adhesive skin closure strips. Closure strips (commonly known by the brand name Steri-Strips) provide light surface support for a wound that’s already well-approximated, often as a finishing step after deeper sutures have done the actual structural work, not as a stand-alone alternative to suturing a wound with any real tension on it.
• Sutures vs. wound dressings. A dressing manages the wound environment after closure — protecting it, managing moisture and exudate, and reducing infection risk — rather than providing the mechanical closure itself. See this site’s guide to selecting wound care supplies for the dressings side of that distinction.

Sutures are also frequently procured and stocked alongside other single-use procedural consumables such as the butterfly needle used for blood draws and short infusions — different clinical purpose, but the same general category of disposable, sterile, single-use procedural supply from a purchasing and inventory-management standpoint.

Why this matters for research administration and procurement

For research administrators and clinical research coordinators, sutures aren’t usually something you select clinically, but they show up in adjacent responsibilities. Sutures are a classic example of a physician preference item (PPI) — a supply category where individual surgeons have strong, clinically justified preferences for a specific brand, material, or size, which complicates standardization and cost-control efforts in procurement and supply-chain planning. Suture material and technique also appear directly in surgical-site-infection prevention work: see this site’s SSI prevention bundle elements guide for how wound closure fits into the broader bundle of practices facilities track to reduce SSI rates. For a clinical trial site with a surgical or procedural intervention arm, confirming that the site’s suture and wound-closure supply chain is stable and appropriately documented can be a genuine, if easy-to-overlook, part of site-readiness review.

Frequently asked questions

Is a suture the same thing as a stitch?

Yes, in everyday usage. “Suture” is the clinical term for both the material (the strand) and, informally, for an individual pass of that material through tissue — “stitches” is the common lay term for the same thing.

What are sutures made of?

Either a natural material (such as processed collagen from animal intestinal tissue, or silk) or a synthetic polymer. Synthetic materials are more common in contemporary practice because their absorption and strength characteristics are more consistent and predictable.

What’s the difference between absorbable and non-absorbable sutures?

Absorbable sutures are broken down and cleared by the body over time and don’t need to be removed; non-absorbable sutures keep their strength indefinitely and either stay in permanently for structural support or are removed once the wound has healed enough to hold together on its own.

Do all sutures need to be removed?

No. Absorbable sutures are designed to be left in place and broken down by the body. Only non-absorbable sutures placed with the intent of removal (commonly certain skin closures) need a follow-up visit to take them out.