58551460 healing and wound care surgery 2

8/6/2019 58551460 Healing and Wound Care Surgery 2

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Types of wounds

Wounding: disruptionoftissueintegrity

y Insect bite:

y Laceration:

y Scalpavulsion:

y Electricalburn: probablywillsustaindigitalamputation

y Burn

y Foreign body reaction: fromsiliconeinjection. Picturethatfollowsshows

revisionalsurgery.

Subject: SURGERYTopic: Healing and Wound careLecturer: Dr. MarquinaDate of Lecture: June 22, 2011Transcriptionist: MopsterPages: 11 S

Y

2011-2012


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General Objectives

Attheendofthelecture,thestudentsshouldbe

abletodiscussthebasicconceptsofwoundhealing,

as wellas,thefundamentalprinciplesofwound

management.

Specific Objectives

y Attheendofthelecture,thestudentsshouldbeableto:

o Todiscussthebodysresponsetoinjuryandthesequenceofeventsthatfollow

duringthecourseofnormalwound

healing,o Todefinetheeffectsoflocalandsystemicfactorsonwoundhealing

o Todescribethestepsintheproperevaluation,care,andtreatmentofthe

differenttypesofwounds

Course Outline

I. HistoricalbackgroundII. Biologyofnormalwoundhealing

A. Phasesofwoundhealing1.

Inflammatoryphase2. Proliferativephase

3. Maturationandremodelingphase

B. EpithelializationC. Wound ContractionD. Fetalwoundhealing

III. Factorsaffecting woundhealingIV. Excessivehealing/abnormalscarsV. Woundcareandmanagement

A. ClassificationofwoundB. TypesofwoundclosureC. LocalwoundcareD. Dressings

Historical Background

y Ancienttimeso 2000 BC Sumerians

Incantations: probablyinthebeliefthatthe woundswerecausedby

evilspiritsorthegods.

Applicationofpoulticelikematerials

o 1650 BC: Egyptianpapyrusdocuments Infectedvs.noninfectedwounds Usedconcoctionscontaining

Honey (antibacterialproperties Lint (absorbentproperties) Grease (barrier)fortreating

woundso 2nd-3rdcenturyAD

Greeks Acutevs.chronicwounds Practicedgentletissuehandling,foreignbodyremoval,

suturingskinedges,and

protectingthewound with

cleanmaterials

Galen,adoctorto Romangladiators Emphasizedtheimportanceofamoistwoundenvironmentto

ensureadequatehealing

o Present Mid 1500: Ambroise Pare (Frencharmydoctor)

Rediscoveredthevalueofgentlemethodsofwoundcare

Woundshealedrapidly whenmildermeasureswereused.

1728 - 1793: John Hunter Injuryalonehasinallcasesatendencytoproducethe

depositionandthemeanstoproduceacure

1818-1865: Ignaz PhilippSemmelweiss (Hungarian

obstetrician)

Introducedwashingofhandswithsoapandhypochloriteto

decreasepuerperalinfection.

Duringthosetimes,the

students,sometimescoming

fromanatomydissections

assistedwithdeliveries,whichprobablyledtomany

infections.

1822-1895: Louis Pasteur. Conceptofgermsenteringthe

woundfromtheenvironment.

Usedphenoltodisinfectinstrumentsand OR which

resultedinamarkedlyreduced

mortalityrate

1876: Robert Johnson. Antisepticdressing (cottongauzeimpregnatedwith

iodoform)

1929: Howe,etal 3 classicphasesofwoundhealing

1962:Winter. Provedscientificallythatepithelializationrateincreased


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by 50% inamoist wound

environment

Recentadvancesinresearchhavenotchangedour

knowledgeoftheeventsofwoundhealingbut

ratherhaveaddednew informationonthemethods

bywhichwoundhealingresponsesarecontrolled:

y Inflammatorycytokinesy Growthfactorsy Bioengineeredtissues: for woundcoverage

Biology of Normal Wound Healing

Phases of Wound Healing

1. Inflammatory (hemostasisandinflammation)

2. Proliferative (Fibroblasticphase)3. Maturationand Remodeling

Thereisoverlapofthestages

Time Sequence of Classical Wound Healing

y Notetheoverlapofthedifferentstages

Inflammatory Phase (Hemostasis and

Inflammation)

y Inflammationo Vascularandcellularresponseo Servestocleanthewoundofdevitalizedtissueandforeignmaterial

y Stimulustoinflammationo Physicalinjuryo Antigen antibodyreactiono Infection

y Aftertheinjury,initialchangesarevascular.

o Within 5-10minutes,vasoconstrictionoccurstoslow bloodflow

o Followedbyactivevasodilationandincreasedpermeability

o Platelets,erythrocytes,leukocyteslinethevessel wallsandserumgainsentry

intothewoundWoundingdisruptstissueintegrityDivisionof

bloodvesselsDirectexposureofextracellular

matrix (collagen)toplateletsPlateletaggregation

anddegranulationActivationofcoagulation

cascade

Platelet activation results in:

y Releaseofwoundactivesubstanceso Plateletderivedgrowthfactor (PDGF)o Transforminggrowthfactor (TGF)o Plateletactivatingfactoro Fibronectino Serotonino Promotemigrationandadhesionofneutrophils,monocytes,fibroblasts,andendothelialcellsintothewound

Activation of coagulation cascade

y Culminatesintheformationoffibrinclotwhichservesasscaffoldingforthe

migrationofPMNs,monocytes,and

fibroblastsintothewound


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Cellular infiltration follows a characteristic pattern:

y Note: plateletscomefirst,lasttoarrivearethefibroblastsandcapillaries.

Polymorphonuclear cells (PMNs)

y Neutrophilso 1stinfiltratingcellso Peakat 24-48 hourspost woundingo Phagocytosisofbacteriaandtissuedebris (maintaskistocleanwound)o Releasescollagenases

Matrixandgroundsubstancedegradation

o Do notappear toplaya role incollagen deposition oracquisition of

mechanicalwound strength

Simpsonand Rossinducedneutropeniainguineapigs,and

notedthatintheabsenceofgross

infection,woundrepairproceeded

identicallytothatofnormalanimals

Macrophages

y Frommonocytesy Peakat 48-96 hourspost woundingy Wounddebridemntviaphagocytosisy Contributetomicrobialstasisbyoxygenradialandnitricoxidesynthesis

y Releasecytokinesandgrowthfactorsthatregulatefibroblastproliferation,matrix

synthesis,andangiogenesis

y Activatedby:o IL-1o TNFo TGFo VEGF (VascularEndothelialGrowthFactor)

o Insulin likeGrowthFactoro EpithelialGrowthFactoro Lactate

Leibovich and Ross

y Completedisappearanceofmacrophagefromthewoundbyadministrationof

systemhydrocortisoneandsubcutaneous

antimacrophageserum

y Documentedimpairmentofphagocytosis,qualitativeaswellasquantitativedecrease

infibrinogenesis

T-Lymphocytes

y Peakat 1 weekpostinjuryo Producelymphokineso Foundtobothinhibitandstimulatefibroblastrecruitmentandproliferation

y Peterson,etal,haveshownthat:o DepletionofTlymphocyteswithin 1

weekafterwoundingresultsin

impairedcollagensynthesisand

deposition,anddecreasedbreakingstrengthofthe wound

Proliferative Phase

y Beginsaround 4thdayandlasts 2-4 weekspostinjury

y Fibroblasts (matrixsynthesis)andendothelialcells (angiogenesis):most

importantcellsatthisstage.

y Culminatesinthere-establishmentoftissuecontinuity

yFibroblastso ActivatedbycytokinesandGFsreleasedbymacrophages

o Movealongaframeworkoffibrinfibersestablishedduringtheinitialhemostasis

o Responsibleformatrixsynthesis(glycosaminoglycansandfibrillar

collagen)

y Endothelialcellso Participateinangiognenesiso Migrateandreplicateformnewcapillarytubulesunderinfluenceof

TNF,TGF, VEGF

y Matrixsynthesiso GAGS

Groundsubstancethatplaysaroleinthesubsequentaggregationof

collagenfibers

Anamorphousgelmadeupofarepeatingdisaccharideunits

attachedtoaproteincore

Chondroitin 4 sulfate Dermatansulfate Heparansulfate Hyaluronicacid

o Collagen Mostabundantproteininthehumanbody

18 types; 5 typesarefoundinhumanbody

Type I (skin,tendon,andbone)is90% ofallcollagen

NormalskincontainsType I and IIIcollageninratioof4:1

Typeanddistributionofcollagen(seebelow):


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y Reorganizationofpreviouslysynthesizedcollagen

o Morestableandpermanentcrosslinksareestablished

o Gainintensilestrengthy NormalType I: Type III collagenratioof4:1isachieved

y Remodelingcontinuesfor 6 12monthspost-injury

y Initiallyindurated,raisedandpruriticscarbecomesamaturescar

o Largenumberofnew capillariesgrowingintowoundregressand

disappear

o Watercontentoftissuereturntonormal

o AvascularandacellularscarEpithelialization

yProliferationandmigrationofepithelialcellsadjacenttothe wound

y Begins within 1 dayofinjuryy Seenasthickeningoftheepidermisatthe

woundedge

y Reepithelializationiscompleteinlessthan48 hoursinthecaseofapproximated

incisedwound

y Insplitthicknessgraftdonor orsuperficialpartialthicknessburns,healingconsists

primarilyofre epithelializationwith

minimalornofibroplasiasandgranulation

tissueformation

y Process:o Mobilization

Epithelialcellsimmediatelyadjacentto woundenlarge,flatten

anddetachfromneighboringcells

andthebasementmembrane

o Migration Lossofcontactinhibition,socellmovesawayfromitsoriginal

neighboringcells.

Cellsflow awayfromtheadjoincellsuntiltheymeetcellsfromthe

oppositesideofthewound

o Mitosis Fixedbasalcellsdividetoreplacethemigratingcellswhilethe

migratingcells,inturn,alsodivide

andmultiply

o Cellulardifferentiation Uponreepithelialization,theorderlyprogressionfromthebasal

mitoticcellsthroughlayersofdifferentiatedkeratinocytesto

stratumcorneumisagain

established

Wound Contraction

y Partoftherepairprocessthatclosesagapinsofttissue

y Theareaofthe woundisdecreasedbythisaction (healingbysecondaryintention)

y Incontrasttocontracturewhichis:o Undesirableeffectofwoundhealingo Shorteningofthescarthatmayresultindeformities

o Maybeduetocontraction,fibrosis,orothertissuedamage

y Myofibroblastso Cellspostulatedtoberesponsiblefor

woundcontraction (stillcontroversial)

o Cytoskeletalstructure (smoothmuscleactin)

o Wellformedintercellularattachmentssuchasdesmosomesandmacula

adherens

Fetal Wound Healing

y LackofscarformationyMoreofaregenerativeprocesswithminimalornoscarformation

y Transitionwoundo Occursatthebeginningofthe 3rdtrimester

o Scarlesshealingbutthereisalossofabilitytogenerateappendages

Difference between adult and fetal wound healing

y Woundenvironmento Fetusisbathedinsterileandtemperaturestablefluidenvironment

o Howeverscarlesshealingcanoccuroutsidetheamnioticfluidenvironment

y Inflammationo Reducedfetalinflammationduetotheimmaturityoftheimmunesystem

o Less PMNsandmacrophagesy GrowthFactors

o AbsenceofTGF StudieshaveshownthatneutralizingTGF usingantibiotics

reducescarformationinadult

woundso Woundmatrix

Fetalfibroblastsproducemorecollagen

Excessiveandsustainedhyaluronicacidproductioninthefetus which

mayaidintheorderlyorganization

ofcollagen

Factors Affecting Wound Healing

y OxygenoFibroblastsareoxygensensitive

o Collagensynthesisoccursat PO2is>40mm Hg

o Fibroblastandcollagenproductioncanbestimulatedbymaintainingthe

woundinastateofhyperoxia

y Hematocrito Mildtomoderatenormovolemicanemiadoesnotadverselyaffect


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collagensynthesis,unlessthe

hematocritfallsbelow 15%

y Infectiono Threshold >105microorganisms/gmoftissueorlowerfor hemolytic

streptococcus

o Decreaseleukocytechemotaxisandmigration,phagocytosis,and

intercellularkillingo Impairsangiongenesisandepithelialization

o Promotescollagenolyticactivityresultingindecreasedwoundstrength

andcontraction

y Radiationtherapyo Stasisandocclusionofsmallvesselso Directadverseeffectofionizingradiationonfibroblastproliferation

o Decreasedin woundtensilestrengthandtotalcollagendeposition

o Recommendationisthoroughdebridementandcoverage withawell

vascularizedflap

y Chemotherapyo Generallydecreasefibroblastproliferationandwoundcontraction

y Smokingo Nicotine: producevasoconstrictionandlimitcapillarybloodflow necessaryfor

distalperfusion

o Carbonmonoxide: Formscarboxyhemoglobin;shiftsoxygen-hemoglobincurvetoleft

y Ageo Tensilestrengthandclosureratesdecreasewithage

o Thephasesofhealingareprotractedasonegetsolder

y Nutritiono Proteinenergymalnutritionimpairsfibroplasiasanddiminishcollagen

deposition

o Malnutritioncorrelateswithhighratesofwoundcomplicationo Nutritionalintervention (parenteralorenteral),canreversetheeffectof

malnutritionorpostoperative

starvationonhealing

y Steroidso Inhibitwoundmacrophageso Interfereswithfibrogenesis,angiogenesis,andwoundcontraction

y VitaminAo

Stimulatescollagendepositionandreepithelialization

o Contributestoincreasedbreakingstrengthofwounds

o VitaminAdeficiencyretardswoundrepair

o VitaminArestoresmonocyticinflammationthathasbeenreplacedby

anti inflammatorysteroids

Dailyoraldoseof25,000 IU Topicalapplicationof200,000 IUevery 8 hours

y Vitamin Co Essesntialcofactorinsynthesisofcollagen

o Scurvyor Vitamin C deficiciency Failureofcollagensynthesisandcrosslinking

Formationofdefectivecapillariesleadingtolocalhemorrhages

Muscleweakness,jointandmuscleaches,rashesonlegs,andbleeding

gums

o Excessiveconcentrationsdonotpromotesupranormalhealing

y Zinco Constituentofseveralenzymesessentialfornormal woundhealing

o Low serumlevelsimpairepithelialandfibroblasticproliferation

o Studieshaveshownthatzincenhanceswoundhealingonlywhenthereisapre

existingzincdeficiencystate

y Diabetesmellituso Resultsinreducedinflammation,angiogenesis,andcollagensynthesis

o Largeandsmallvesseldiseasescontributestolocalhypoxemia

o Carefulpreoperativecorrectionofbloodsugarlevelsimprovesoutcomeof

woundsinpts.o Insulinrestorescollagensynthesisandgranulationtissueformationtonormal

levels

Excessive Wound Healing/Abnormal Scars

y Widespreadscarsy Hypertrophicscarsy Keloids

Apreferredscarisonethathasmaturedrapidly

withoutcontractureorincreaseinwidth,and

withoutformingmorecollagenthannecessaryforitsstrength.

Wide spread scar

y Typicallyflat,wide,andoftendepressedy Consequenceofcontinuedtensioninthedermis (coveredbyepidermisinstead)and

mobilityofthe wound


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controlofinfectionby

debridementandantibiotic

Decubitus/Pressure Ulcer Whensofttissueiscompressedbetweenbonyprominenceand

externalsurface

Excessivepressurecausescapillarycollapseandimpedes

thedeliveryofnutrientsto

tissues

Riskfactorsincludeimmobility,chronicconditions,alteredmentalstatus

Pressureulceratthetrochantericarea

Stages of Pressure Ulcer Formation

I. NonblanchingerythemaofintactskinII. PartialthicknesskinlossIII. Fullthicknessskinlossbutnotthru

fascia

IV. Fullthicknessskinloss withinvolvementofmuscleandbone

Marjolins Ulcers:

y Malignanttransformationoflong standingchroniculcer

y Squamousorbasalcarcinomas

Types of Wound Closure

y Primary intention orprimary closureo Woundedgesareimmediatelyapproximatedusingsutures,staples,or

tape

o Delayedprimary closure: incontaminatedwounds, woundedges

areapproximatedafteradelayof

severaldays

y SecondaryIntention orSecondaryClosureo Duetobacterialcontaminationandtissueloss,thewoundisleftopento

healbygranulationtissueformation

andcontractiony TertiaryClosure

o Woundisclosedbybringingtissuesfromelsewhereintheformofgraftor

flap

y Seebelow: scarformationforthedifferenttypesofclosure.

Local Wound Care

y Obtainahistoryofeventssurroundinginjury

y Examinethewoundtoassessitsdepthandconfiguration,extentofnon-viabletissues

as wellasthepresenceofFBandcontaminants

y Irrigationanddebridementoftheedgesofthewoundunderlocalanesthesia

o Highpressure (70 PSI)irrigationwithnormalsaline

o Gentlehandlingoftissueso Marginallyviableflapofskinandtissuesshouldberesectedorrevascularized

beforewoundrepair

o Useofpovidoneiodine,hydrogenperoxideimpairwoundhealing

y Antibioticadministrationo Mustappropriatefororganismo Mustbegivenatpropertime,inproperdose,viaproperroute

Eg,electivesurgery,contaminated,traumaticwounds

y Tetanusprophylaxisy Planningthetypeandtimingofwoundrepair


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Important points

1. Regardlessofthecauseofinjury,thebodyrespondsinapredictablesequenceof

events

2. Anunderstandingofthebiologyofnormalwoundhealingguidesthephysicianinthe

careofwounds.

3. Severallocalandsystemicfactorsaffectwoundhealing;controllingthesefactorswillensurethatthenormalprocessesof

woundhealingshallproceedefficiently

4. Inthecareofwounds,thephysicianmustrememberthebasicsurgicalprinciples:

gentlehandlingoftissues,maintenanceof

aseptictechnique,ensuringtissueviability,

andavoidanceoftension.

Endoftranscription

Inallthesethingswehavecompletevictory

throughhim wholovedus. Romans 8:37-39

58551460 healing and wound care surgery 2

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