Wound Closure Techniques Notes

Walking Sutures

  • Purpose: to advance skin toward the center of the wound when edges cannot be closed directly

  • Placement: pass the suture through the fascia of the body wall at a distance closer to the wound center than the bite through the subdermal fascia or deep dermis

  • Key note: the distance from “a” to “b” increases because of skin stretching when the suture is tied

  • Indications: Ideal for large open wounds with surrounding skin that is pliable

V-Y Plasty

  • Provides a flap of skin that can be advanced into a defect to provide tension relief adjacent to an orifice

  • Indicated for chronic defects surrounded by inelastic skin and closing wounds near structures that would be distorted by closure under tension (e.g., eye)

  • Surgical steps: point of Chevron incision made away from the defect; undermine; close in the shape of a Y

Z-Plasty

  • Purpose: makes additional skin available by changing the direction of skin tension

  • Uses: to facilitate closure of nearby wounds when there is sufficient laxity parallel to the wound to permit skin stretch in that direction; or for cicatrix excision

  • Central arm: performed perpendicular to the long axis of the wound and the wound should reside > 3 cm away

  • Flaps: two triangular flaps which are transposed after undermining

M-Plasty

  • Used in fusiform (tapering at ends) wounds where skin at one or both ends is limited

  • Common uses: when one end of incision would be compromised by an orifice, foot pad, or for reconstruction of the cranial aspect of radical mastectomy (e.g., limited skin over sternum)

  • Visual reference: described in Tobias & Johnson, Veterinary Surgery: Small Animal (2012)

Stretching Techniques

  • Skin properties: inherent elastic properties allow approximation of wound edges over small distances

  • Mechanical creep: skin can extend its natural boundaries through mechanical creep when tension is applied gradually over 2-4 days

  • Dermal remodeling: randomly oriented dermal collagen & elastic fibers straighten and elongate, becoming more parallel to tension lines, allowing skin lengthening

  • Stress relaxation: over time, less force is required to maintain stretched position because elastic fibers lose their natural recoil

  • Recruitment methods for skin closure under tension:

    • Pre-suturing (A)

    • Skin stretchers (B)

    • Inflatable tissue expanders (C)

    • Adjustable sutures (D)

  • Examples of devices/approaches:

    • Velcro-based skin stretchers over an open wound (page 9)

    • Pre-tensioning sutures

Closure of Fusiform Shaped Defects

  • Technique: Place 1st suture across the widest part of the wound

  • Rule: Continue to divide each segment of the defect in half with subsequent sutures — the "Rule of Halves"

Closure of Crescent Shaped Defects

  • Technique: Begin at the midpoint and divide each segment of the defect in half with subsequent sutures

  • Suture spacing: space sutures farther apart on the “longer” side of the wound

  • Alternative approach: close from end to middle and remove redundant skin; close in a “T” configuration

Closure of Triangular Shaped Defects

  • Technique: Close the defect as a “Y” by beginning at each point and suturing toward the center

  • Central portion: use a half-buried horizontal mattress stitch to close the central portion of the “Y”

  • Point of greatest tension corresponds to the central limb of the Y

Closure of Circular Shaped Defects

  • Direct apposition method: closes by direct apposition but results in excessive/redundant tissue at both ends of the suture line — dog ears

  • Alternative: divide circle into 3 arcs and meet in the middle; still likely dog ear on at least one arc

  • If adjacent skin is adequate: convert wound into a fusiform shape to reduce dog ears

  • Common application: tumor excisions

Closure of Square/Rectangular Shaped Defects

  • Rectangle defects: double “Y”

  • Square defects: use an “X” pattern

  • Applicability: only suitable when minimal tension is present; otherwise develop a tissue flap

Correcting Dermal “Step Defects”

  • Techniques:

    • Manipulation of knot: pull to low side

    • Placement of suture at the same depth on both sides of the wound

    • Half-buried horizontal mattress: intradermal portion on the low side

    • Use a stiff untied suture from superficial on the high side to deep on the low side

Correcting Dog Ears

  • Clinical concern: dog ears may be sites for seroma formation and are aesthetically unsightly

  • Human data: dermal elevations (DEs) < 8 mm in height regress completely by ~132 days (data from humans); animal data not well established

  • Small DEs: manipulate the skin with sutures; apex cutaneous suture to pull ear down and away from the wound

  • Large DEs: resect and close

  • Techniques described in Tobia s & Johnson reference include:

    • Incise through the middle of DE and resect resultant two triangles at the base and close

    • Resect DE en bloc to turn into fusiform shape; if DE formed because one side longer, make a short right-angle incision at the base of DE to define and resect redundant skin; perform L-shaped closure

Postoperative Analgesia

  • Agent: NOCITA® (bupivacaine liposome injectable suspension)

  • Indication: labeled for single-dose infiltration into the surgical site to provide local postoperative analgesia for cranial cruciate ligament surgery in dogs; off-label use for other procedures

  • Dosage & administration: 5.3 mg/kg (0.4 mL/kg) infiltrated into tissue layers at the time of incisional closure

  • Duration: a single dose may provide up to 72 hours of pain control

Notes and references:

  • Source material cites Tobias & Johnson: Veterinary Surgery: Small Animal, 2012, Saunders/Elsevier

  • Some slides are labeled confidential; practical applications depend on wound characteristics and tissue availability