L9 - DENT323 - Soft Tissue Injuries [15.11.pdf

Soft Tissue Injuries Wound Healing • Regeneration: restitution of tissues is structurally and functionally indistinguishable from native tissue • Repair: tissue integrity is reestablished through formation of fibrotic scar • “spot weld” – replacement tissue is coarse and has a lower cellular conte...

Soft Tissue Injuries Wound Healing • Regeneration: restitution of tissues is structurally and functionally indistinguishable from native tissue • Repair: tissue integrity is reestablished through formation of fibrotic scar • “spot weld” – replacement tissue is coarse and has a lower cellular content than native tissue • Tissue disruption invariably results in repair rather than regeneration • Exception: Bone and Liver Healing by… • First Intention: clean laceration or surgical incision is closed primarily with sutures. Healing proceeds rapidly with no dehiscence and minimal scar formation • Second Intention: conditions less favorable, and more complicated, healing occurs through protracted filling of the tissue defect with granulation and connective tissue • Commonly associated with avulsive injury, local infection or inadequate closure of wound. • Third Intention: Staged procedure for more complex wounds. • Combines secondary intention healing with delayed primary closure • Avulsive or contaminated wound is debrided and allowed to granulate and heal by second intention for 5-7 days • When adequate granulation tissue has formed and risk of infection is minimal, wound is sutured closed to heal by first intention Wound Healing Response • Healing continuum • Coagulationàinflammationàre-epithelializationà granulation tissueàmatrix and tissue remodelling • 3 stages: • Hemostasis and Inflammatory Phase • Proliferative Phase • Remodeling phase Wound Healing • Hemostasis (Immediate) • • Inflammation (1-3 days) • • • • • Vasodilation, increased vascular permeability (histamine, prostaglandins, kinins and leukotrienes) Leukocyte migration and margination, Phagocytosis by macrophages, release of leukocyte products Inflammatory mediators: Proinflammatory cytokines: IlB and TNF PDGF VEGF Fibroblastic Stage (3-21 days) • • • • Vasoconstriction, Platelet Plug via adhesion and aggregation, Coagulation via cascade Fibrin form lattice for fibroblast collagen. Angiogenesis along fibrin strands Fibrinolysis Remodeling (21 to infinity) • • Increases in tensile strength without increase in collagen Scar maturation and evolves over at least a year Wound Healing Initial Exam • Primary Survey ABCs + General Neuro exam, C-spine • Achieve hemmorhage control while stabilizing other more urgent injuries (soft tissue evaluation is secondary survey) • Pressure dressing, sutures or staples, electrocautery • Wounds should be kept moist with gauze soaked in an antibiotic solution until final management. • Timing – no urgency • Face has rich vascularity – no “golden period” (up to 48 hours for clean wounds • Healing of facial wounds is unaffected by time interval • Non facial ST injuries – risk of infection increases with lapse of time • Lacerations may facilitate fracture repair Sequence of Repair • Setting? • Local Anesthesia in ER vs GA in OR • GA: • Large complicated lacerations require ptn cooperation and ideal lighting • Deep structures damaged – exploration, tagging and repair, ID facial nerve with nerve stimulator Wound Debridement • Irrigate and Inspect • Non vital tissue is conservatively excised • Copious irrigation to minimized bacterial flora and removing foreign body • • No difference in infection rates in wounds irrigated with normal saline when compared with other solutions Do not use hydrogen peroxide or povidone-iodine (betadine) • • Impdes wound healing, toxic to fibroblasts (Use only to scrub skin surfaces) Chlorhexidine is shown to be better to clean skin • • “avoid irrigating wound with any solution that would not be suitable for the eye. Avoid mechanical scrubbing in the wound – delays wound healing and increases susceptibility to infection by increasing inflammation- • Irrigation with high enough pressure to disrupt bacterial adherence – fluid jet of psi of 7lb. • Cleaning prevents: • Infection, tattoo, foreign body granuloma, hypertrophic scar. Wound Debridement • Removal of dead tissue fragments, hematomas and foreign bodies. • Limit debridement to devitalized and necrotic tissue • Avoid radical excision of soft tissue in the facial region • err on the side of retaining tissue that may not eventually survive • If wound margin is irregular and reapproximation is difficult, excise to produce clean wound margins and minimize scar formation • Evaluate vital tissue – Deep lacs may transect VII V XII • May require microsurgical techniques to restore function Closure • Sutures, Adhesives, stapling • Layered closure to eliminate dead space • Dead-space causes accumulation of inflammatory exudates leading to infection which can cause tension and necrosis of the skin edges due to impairment of vascular supply and may cause an increase in scarring • Anatomic borders must be re-approximated precisely • Eyebrows, lip margins, eyelids • Prevent dog ears by placing suture in the centre • Deep layers re-approximate with 3.0 or 4.0 buried resorbable sutures • Superficial skin closed with 5.0 or 6.0 sutures. Timing • Skin sutures removed 4-6 days after placement • Wound has regained only 3% to 7% of its tensile strength and adhesive strips help support the margins • 7-10 days after suture removal, collagen has begun to crosslink. Wound can tolerate early controlled motion, little risk of disruption • As wound heals, it contracts along its length and width and becomes inverted due to collagen and fibroblast maturation. • Aim to evert wound edges when suturing • Wound continues to remodel up to a year after injury • By the end of the third week, 20% of the tensile strength is attained and, at the end of the first month, 50% is present. • Never regains greater than 80% of the strength of intact skin Sutures • Diameter of the suture is proportional to the tensile strength • Suture materials should be at least as strong as the tissue in which they are used. • The selection of suture material • • • • • condition of the wound tissue to be repaired strength and knot-holding characteristics reaction of the surrounding tissue to the suture material Types: • • • • absorbable or nonabsorbable, coated or uncoated natural or synthetic, multifilament (braided) or monofilament. Sutures • Natural, nonabsorbable sutures • silk, cotton, and metals such as stainless steel, tantalum, and titanium. • Synthetic, nonabsorbable sutures: • Dacron (Mersilene, Polydek, Tevdek, Ethibond, and Tycron), • Nylon (Ethilon and Dermalon), • Polypropylene (Prolene and Surgilene). • Natural absorbable sutures • • made of catgut and plain and chromic collagen Synthetic absorbable sutures: • polyglycolic acid (Dexon), polyglactic acid (Vicryl), and polydioxanone (PDS), Monocryl (polyglecaprone 25) Sutures • Monofilament • Braided • Single strand • Decrease resistance in tissue • Multistrand • Increase resistance • Resists bacteria • Good handling • Harbours bacteria • More flexible • Lower strength • Less tissue reaction • Stronger • Increased tissue reaction • Absorbable: • Degraded • Enzymes: (gut) • Hydrolysis: (synthetic) • Will degrade quicker in infection or febrile ptn • Can place into Dermis with good tissue response Absorbable Sutures • Gut • • • • • • Animal intestine (98% collagen) Good strength Plain: 7-10 days Chromic: 10-14 days • Treated with chromic acid, decreases degradation, tissue reaction and increases strength Monocryl • Low tissue reactivity, maintains high tensile strength, 10-14 days • Facial wound closure: Subcuticular of dermis. Rare percutaneous • Passes through tissue easier – similar to nylon Vicryl • • • • • • Good handling and tissue response Should be burried OK in infected tissue Indications: Subcutaneous layer Use undyed in face Vicryl Rapid • Irradiated • Indications: superficial closure, short term wound support Nonabsorbable • Nylon • • • • • Braided or monofilament Inert Excellent strength and handling Indication: 5.0 or 6.0 skin closure Prolene • Excellent hold strength • Indication: when very little tissue reaction is desired • Silk • Indication: mucous membrane • Pliable when wet • Cons: Bacterial wick Adhesives • Octylcyanoacrylate • Some studies show similar cosmetic outcomes with suturing • Closure is faster than with sutures, but should be avoided in complex lacerations involving the face where esthetics are a concern • Steri Strips • Use alone or with sutures. Place perpendicular to wound • Reinforced with rayon filament • Decreases tension on margins Refreshing Margins Types of injuries • Abrasions • Contusions • Lacerations • Avulsive Injuries Abrasion • Caused by shear forces that remove a superficial layer of skin. • Gently cleanse wound and irrigate with NS • Usually heals with local wound care. • Foreign bodies may be embedded into the wound • Can cause tatooing • After thorough cleansing, cover with topical antibiotic ointment to minimize desiccation and secondary crusting • Can dress with bactigras and gauze • Re-epithelialization without significant scarring is complete in 7-10 days if the epidermal pegs have not been completely removed. • • Will have scaring if extends into reticular dermal layer. Excision of the remaining dermal tissue with primary closure of the skin wound with 4-0 chromic sutures in the dermal layer and 6-0 nylon sutures at the surface, is indicated • Limit sun exposure in first 6 months - may cause permanent hyperpigmentation. Contusions • Blunt trauma that cause edema and hematoma formation in the subcutaneous tissues. Skin intact • May have extensive soft tissue swelling and ecchymosis. Possible future hyper/hypo pigmentation • Large hematomas should be drained to prevent permanent pigment changes and secondary subcutaneous atrophy • If associated with laceration, excise contused tissue and undermine subcutaneous tissues for tension free closure • If the contused laceration involves vital structures that would not tolerate tissue removal, such as the eyelid or nose, debridement and primary closure should be delayed until the contusion resolves. Lacerations • Caused by sharp injuries to the soft tissue. • Can have sharp, contused, ragged or stellate margins • Depth of penetration should be carefully explored in acute setting • Closure in layered technique. • If margins are ragged, should be conservatively excised to provide perpendicular skin edges to prevent excessive scar formation • Flap like laceration: when a component of the soft tissue has been elevated secondary to trauma. Eliminating dead space by layered closure and pressure dressings is especially important • Simple • • • • Clean: little to debride or prep Contaminated: Close or delay Contused: Remove margin or delay Margins: undermine, go 90 degrees • Stellate • Ragged, usually contused • Strangulation of flap tip • Interrupted sutures until flap tip • Tip: intradermal horizontal mattress • Flaplike: • • • • Significantly undermined soft tissue Subcutaneous or supraperiosteal layer Debris at flap depth TX: replace even small flaps with small pedicle • Pressure dressing to prevent dead space, hematoma and scarring • Avulsions • Loss of segment of soft tissue • If small, can undermine adjacent tissue followed by primary closure • If large, may require local flaps or allowing wound to heal by secondary intention followed by delayed soft tissue techniques (rather avoid in facial wounds) • If significant, skin graft, local flaps or free tissue transfer • Delayed primary closure • Indications: • Extensive edema • Devitalized tissues • Tx: limited debridement, and maintain moist dressing. Antibiotics • Closure when tissue improves • (Rather avoid in facial wounds due to scarring Skin Grafts • Split Thickness • Full Thickness • Thin: .008-.012 • Medium: .012-.018 • Epidermis and dermis • Requires optimum wound • Thick: 0.018-.050 • Rapid Revascularization • Better color, texture • Less contracture • Resilient • Expandible • Donor site must be closed primarily • Multiple donor site • Pressure Dressing 7-10 days • Lubricate • Immobilize and keep tension free Flaps • Rotational • Transpositional • Interpolated • Advancement Flaps Rotational: • Transpositional • Interpolated • Advancement Human and Animal Bites • Bite wounds are prone to infectious complications - Can compromise esthetics more than initial injury • Dog bites most common in children and midface • • Bite force of 200-450psi – examine for fractures Cats – pasturella multicida – 2x higher risk of infection than dog bites • Puncture wounds are difficult to clean – close follow up • Often polymicrobial – aeorobes and anaerobes • Copious irrigation, wound debridement and meticulous primary closure to reduce infection. Immediate closure is safe. Follow criteria for aesthetic reconstructive surgery if extensive. • Abx prophylaxis is debated : Amox Clav is drug of choice • • Bites presenting within 24 hours: Prophylaxis directed at P multicida for infections • Bites presenting after 24 hours of injury Strep and Staph species are more common – chose penicillinase resitant antibiotic. Rabies prophylaxis should be given for bite wounds that occur in unprovoked domestic dog or cats that exhibit bizarre behavior or attack by raccoon skunk, bat, fox or coyote Post Operative Wound Care • Wounds should be monitored closely to determine whether early intervention is indicated to minimize scar contracture or hypertrophic scarring. • May require secondary grafts or flaps. • Important to keep a wound clean and scab free • More rapid epithelialization. • Moist environment favorable with abx ointment • Diluted hydrogen peroxide is useful in the postoperative period in cleaning crusts away from incision lines to minimize scaring • Daily dressing with polymyxin B and polysporin is standard • Avoid sun exposure for first 6 months after injury to avoid hyperpigmentation • Thank You