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Complete Guide to Suturing: Types, Techniques & When to Use Them

1. Before You Suture - Wound Assessment

Key prep steps (from Rosen's Emergency Medicine): Irrigate heavily with tap water or 0.9% saline using high-pressure syringe (18-gauge needle + 30 mL syringe = 7-8 psi). Debride only clearly devitalized edges. Avoid povidone-iodine directly in the wound at >1% concentration.

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2. Suture Materials - Absorbable vs. Non-absorbable

Absorbable Sutures (used deep / inside tissues)

Non-absorbable Sutures (used on skin surface - must be removed)

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3. Suture Size Chart (USP Scale)

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4. Needle Types

• Reverse cutting (3/8 circle) - Most common for skin; the cutting edge faces outward, reducing tissue tear-through
• Conventional cutting - Edge faces inward; tends to cut toward wound; less preferred for skin
• 3/8 circle - Standard for most skin closures
• 1/2 circle - Deep, confined spaces (abdominal wall, oral cavity)

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5. Types of Suture Techniques

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A. Simple Interrupted Suture

1. Enter needle at 90° to skin, ~5 mm from wound edge
2. "Scoop" through dermis and exit equidistant on the other side
3. Leave a 2-3 cm tail; tie with instrument tie (2-1-1 throws minimum)
4. Place sutures ~5 mm apart along the wound
5. Wound edges should be slightly everted (not flat or inverted)

• Most standard lacerations - face, scalp, trunk, extremities
• Irregular/jagged wounds and curvilinear lacerations (interrupts distribute tension better)
• High-tension wounds (each stitch is independent; one failure doesn't open the whole wound)
• Blunt trauma cuts with irregular edges

From Rosen's: "Wound closure with simple interrupted sutures is the most common method of laceration repair in the ED and the majority of wounds can be closed with this technique."

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B. Running (Continuous) Suture

• Linear lacerations under minimal tension
• Longer wounds where speed matters
• Scalp lacerations
• When there is low risk of infection

• Simple running - faster, good for scalp
• Running locked (Ford interlocking) - more hemostatic, good for bleeding wounds
• Running subcuticular - passes horizontally in the dermis; best cosmetic result, no cross-hatch marks

From Rosen's: "The running technique is appropriate for linear lacerations under minimal tension when there is a low risk of infection. Curvilinear or jagged wounds are best closed with interrupted sutures."

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C. Vertical Mattress Suture

• Wounds prone to inversion (back of hand, foot, interdigital areas)
• High-tension wounds (joints, back, shoulders)
• Wounds where skin edges tend to roll inward
• Thick skin areas

Tintinalli's Emergency Medicine notes: "Simple interrupted sutures often lead to skin inversion and risk of failure of the initial wound repair with interdigital lacerations. The more effective closure technique is to place horizontal or vertical mattress sutures."

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D. Horizontal Mattress Suture

• Very high-tension wounds (fasciotomy closures, scalp)
• Fragile or thin skin (elderly patients)
• Areas needing hemostasis (bleeding scalp edges)
• As retention sutures in abdominal closures

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E. Corner / Half-Buried Horizontal Mattress Suture (Three-Point Stitch)

• Flap tip closures (triangular / V-shaped lacerations)
• Stellate lacerations
• The needle never directly passes through the flap tip, so blood supply is preserved

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F. Buried / Intradermal (Deep Dermal) Suture

• Deep wounds to eliminate dead space
• Reducing skin tension before surface closure
• NOT in contaminated wounds (increases infection risk)
• NOT through adipose tissue alone

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G. Subcuticular (Intradermal Running) Suture

• Best cosmetic result (no "railroad track" marks)
• Elective surgical wounds, facial lacerations, clean accidental cuts
• Used with absorbable (Monocryl) or removable (Prolene) suture

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6. Which Suture Where - By Body Region

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7. Blunt Trauma Cuts vs. Clean Accidental Cuts

Blunt Trauma (e.g., falling on concrete, head hit on wall)

• Wound edges are irregular, crushed, or stellate
• More contamination, more devitalized tissue
• Use: Interrupted sutures (best tension distribution), vertical mattress at high-tension areas, corner stitch for flap tips
• Irrigate more aggressively before closing
• Consider delayed primary closure if heavily contaminated

Clean Accidental Cuts (e.g., knife, glass)

• Wound edges are sharp and well-defined
• Minimal contamination
• Use: Simple interrupted or running suture; subcuticular for cosmetically sensitive areas (face)
• Can approximate edges more precisely

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8. Alternative Closure Methods

• Staples - Scalp, trunk, extremities where cosmesis is less important. Fast, low infection risk. NOT for face, hands, joints.
• Tissue adhesive (Dermabond) - Short (<4 cm), low-tension, clean wounds on face. No injection needed. Not for joints or hands alone.
• Steri-strips - Very superficial, low-tension wounds; or as backup after suture removal.

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Key Decision Summary

Is the wound contaminated / bite?  →  Do NOT close primarily
       ↓ No
Is it >6-8 hours old (or >12h face)?  →  Consider delayed closure
       ↓ No
Clean, sharp cut, low tension?  →  Running or subcuticular suture
       ↓
Jagged / irregular / high tension?  →  Interrupted sutures
       ↓
Skin edges inverting? (hand, foot)  →  Vertical mattress
       ↓
Triangular flap / stellate?  →  Corner stitch (3-point mattress)
       ↓
Deep wound / dead space?  →  Buried deep Vicryl first, then surface suture

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