Catgut Suture

Origin & Composition

Types

Remnants of both plain and chromic gut have been detected in wounds more than 2 years after placement, despite nominal absorption timelines. — Roberts and Hedges' Clinical Procedures in Emergency Medicine

Mechanism of Absorption

Properties

Catgut → Cotton → Silk → Synthetic absorbable / Multifilament nonabsorbable → Nylon → Steel → Polyethylene → Polypropylene — Hinman's Atlas of Urologic Surgery

Wound Strength vs. Suture Strength

• Plain catgut: stronger than surrounding soft tissue wound for ≤7 days
• Chromic catgut: stronger for 10–21 days
• Compare: nylon, wire, and silk remain stronger for 20–30 days
• Roberts and Hedges' Clinical Procedures in Emergency Medicine

Relative Absorption Timeline (Subcutaneous Tissue)

Oral Cavity Absorption (faster environment)

Behavior in Infected/Contaminated Wounds

• In infected urine, catgut sutures actually retain the most strength compared to other absorbable sutures.
• However, the infection rate in contaminated wounds closed with catgut is higher than with polyglycolic acid sutures, due to its high tissue reactivity.
• Highly reactive material like catgut should be avoided in contaminated wounds.

Clinical Uses

• Episiotomy repair: Historically used with chromic catgut; evidence now supports polyglactin 910 (Vicryl) as superior for reduced pain and complications.
• Pediatric facial lacerations: Fast-absorbing catgut is comparable to nylon for infection rates, dehiscence, and cosmetic outcomes — with the advantage of not requiring suture removal (important in anxious children). (Pfenninger and Fowler's Procedures for Primary Care)
• Urologic/gastrointestinal surgery: Chromic catgut used in mucosal closures (e.g., bladder, bowel anastomosis).
• Gynecologic procedures: Used in original descriptions of Burch and MMK colposuspension procedures.
• Oral/dental procedures: Short absorption makes plain gut practical for intraoral use.
• Bleeding control: Topical hemostatic procedures — 5-0 chromic or catgut on a taper-point needle.

Knot-Tying Requirements

• Plain gut: poor knot security — requires extra care
• Chromic gut: fair knot security
• General guidance: tie synthetic absorbable sutures with 3 knots minimum; gut sutures need the same attention given their tendency to slip

Disadvantages vs. Synthetic Absorbables (e.g., Vicryl, Dexon)

1. Variable and unpredictable absorption time
2. Lower and erratic tensile strength
3. Highest tissue reactivity of all sutures → more inflammation
4. Higher infection risk in contaminated wounds
5. Tendency to fray when handled
6. Poor knot security
7. Stiffness despite softening fluid packaging

Catgut Suture — Advantages & Indications

Advantages

1. Natural Biodegradability (No Removal Needed)

• Pediatric patients (children fearful of suture removal)
• Internal/deep tissues that are inaccessible after closure
• Patients unlikely to return for follow-up

In one study, fast-absorbing catgut was comparable to nylon for facial lacerations in children, with the key benefit of no requirement for suture removal. — Pfenninger and Fowler's Procedures for Primary Care

2. Rapid Absorption When Needed

• Plain gut absorbs in 10–40 days (or just 3–5 days in the oral cavity)
• Fast-absorbing catgut disappears from skin surface in 9–13 days
• Ideal when only short-duration wound support is required

3. Good Performance in Infected Urine

• In infected urine, catgut retains the most tensile strength of all absorbable sutures
• Makes it a practical choice for urologic procedures in the setting of urinary tract infection — Hinman's Atlas of Urologic Surgery

4. Adequate Initial Tensile Strength

• Catgut is stronger than the surrounding soft tissue wound for up to 7 days (plain) or 10–21 days (chromic)
• Sufficient for tissues that heal rapidly (mucosa, subcutaneous tissue)

5. Cost-Effectiveness

• Catgut is generally less expensive than synthetic absorbable alternatives (Vicryl, PDS, Monocryl)
• Relevant consideration in resource-limited settings

6. Established Track Record in Key Procedures

• Has a long history in gynecological, urological, and general surgery — original descriptions of Burch colposuspension and MMK procedure used chromic catgut
• Widely understood handling characteristics for trained surgeons

7. Good Handling in Delicate Tissues (Chromic)

• Chromic catgut treatment with chromium salts imparts increased flexibility and smoother surface
• Advantageous when suturing delicate or friable tissues

Indications

Plain Catgut

Chromic Catgut

Summary: When to Choose Catgut

• Short-term support is all that is needed (healing tissue, mucosa)
• Suture removal is impractical (children, intraoral, internal structures)
• Cost is a limiting factor
• Working in a urinary/infected environment where synthetic absorbables may fail earlier
• The procedure historically/conventionally calls for it (episiotomy, urology)

• Wound is contaminated (higher infection risk vs. polyglycolic acid)
• Long-duration support is needed (fascia, slow-healing tissues)
• Tissue reactivity must be minimized