The Wound VAC:The Wound VAC:The Hoover of healingThe Hoover of healing

Karen LoKaren Lo10/5/0910/5/09

R2R2University of ColoradoUniversity of ColoradoDepartment of Surgery Department of Surgery

OverviewOverview

Background on woundsBackground on wounds

Biology of wound healingBiology of wound healing

Deterrents and aids to wound healingDeterrents and aids to wound healing

Science behind Wound VACScience behind Wound VAC

Clinic studies supporting Wound VACClinic studies supporting Wound VAC

Why are wounds Why are wounds relevant?relevant?

Wounds are a significant burdenWounds are a significant burden Chronic wounds alone affect:Chronic wounds alone affect:

over 5 million patientsover 5 million patients Cost of wound: Cost of wound:

20 billion dollars a year20 billion dollars a year

Biology of Wound HealingBiology of Wound Healing

Wound healing Wound healing phasesphases

InflammatoryInflammatory ProliferativeProliferative RemodelingRemodeling

Inflammatory StageInflammatory Stage

Days 0Days 0--44 Starts with Starts with

Hemostatsis Hemostatsis –– platelets dominateplatelets dominate

Then on to Then on to InflammationInflammation–– Leukocytes and Leukocytes and

macrophages macrophages dominate dominate

Proliferative Proliferative phasephase

Days 3Days 3--1414

FibroblastsFibroblastsdominant cell typedominant cell type

Maturation phaseMaturation phase

Days 14 onwardsDays 14 onwards Collagen Collagen

crosslinking crosslinking and and reorganization reorganization

Fibroblasts Fibroblasts differentiate into differentiate into Myofibroblast Myofibroblast

Barriers to wound healingBarriers to wound healing

InfectionInfection–– 100,000 bacteria per gram tissue100,000 bacteria per gram tissue

Excess edema or excess drynessExcess edema or excess dryness

Poor blood flowPoor blood flow–– Hypoxia due to smoking or diseaseHypoxia due to smoking or disease

Healing optimizationHealing optimization

Clean and protected environmentClean and protected environment PerfusedPerfused

–– Tissues getting cells and oxygenTissues getting cells and oxygen

Moist environmentMoist environment Minimize exudate and edemaMinimize exudate and edema

What can do all this??What can do all this??

WOUND VAC !!WOUND VAC !!

The Wound VAC!!The Wound VAC!!Negative pressure wound therapy NPWTNegative pressure wound therapy NPWT

Topical Negative Pressure TNPTopical Negative Pressure TNP

How it works:How it works: Polyurethane Foam is Polyurethane Foam is

placed in wound bed, placed in wound bed, sealed with occlusive sealed with occlusive dressingdressing

Evacuation tube Evacuation tube embedded in foam embedded in foam dressingdressing

Applies localized Applies localized negative pressurenegative pressure

Why it worksWhy it works

Primary effectPrimary effect Contraction of woundContraction of wound Stabilization of woundStabilization of wound Removal of Removal of extracellular extracellular fluidfluidSecondary effectsSecondary effects Increase in blood flowIncrease in blood flow Increase granulation tissueIncrease granulation tissue Increase compliance due to fewer dressing Increase compliance due to fewer dressing

changeschanges

Basic science researchBasic science research

Pig model Pig model On each animal On each animal

wound treated with wound treated with V.A.C. compared to V.A.C. compared to Sterile Saline gauzeSterile Saline gauze

Morykwas Morykwas MJ, V.A.C: a new method for wound control and treatment: MJ, V.A.C: a new method for wound control and treatment: animal studies and basic foundation. animal studies and basic foundation. Ann Ann Plast SurgPlast Surg.. 1997;38(6):5531997;38(6):553--562562

Basic science researchBasic science research

Blood flow levels increased Blood flow levels increased fourfoldfourfold when when 125 mmHg 125 mmHg subatmospheric subatmospheric pressure usedpressure used

Significantly Significantly increased rate of granulation increased rate of granulation tissuetissue formation occurred with NPWTformation occurred with NPWT

Tissue bacterial counts significantly Tissue bacterial counts significantly decreaseddecreased after 4 days of applicationafter 4 days of application

Morykwas Morykwas MJ, V.A.C: a new method for wound control and treatment: MJ, V.A.C: a new method for wound control and treatment: animal studies and basic foundation. animal studies and basic foundation. Ann Ann Plast SurgPlast Surg.. 1997;38(6):5531997;38(6):553--562562

Basic science researchBasic science research

32 Japanese large32 Japanese large--ear white rabbits.ear white rabbits.

Left ears were Left ears were treated with treated with negative pressure negative pressure wound therapywound therapy

Right ears (control Right ears (control group) treated with group) treated with petrolatum gauze petrolatum gauze

Chen SZ: Effects of VAC on wound microcirculation: an experimenChen SZ: Effects of VAC on wound microcirculation: an experimental study,tal study,Asian J Asian J SurgSurg 2005, 28(3):2112005, 28(3):211--77

Basic science researchBasic science research

VAC promoted VAC promoted –– capillary blood flow capillary blood flow

velocityvelocity–– increased capillary increased capillary

caliber and blood caliber and blood volumevolume

–– stimulated stimulated endothelial endothelial proliferation and proliferation and angiogenesisangiogenesis

Chen SZ: Effects of VAC on wound microcirculation: an experimentChen SZ: Effects of VAC on wound microcirculation: an experimental study,al study,Asian J Asian J SurgSurg 2005, 28(3):2112005, 28(3):211--77

Clinical StudiesClinical Studies

1997 study of 300 patients1997 study of 300 patients–– 175 chronic wounds175 chronic wounds–– 94 sub acute wounds94 sub acute wounds–– 31 acute wounds31 acute wounds

Findings:Findings:–– 296 wounds responded to VAC treatment296 wounds responded to VAC treatment–– VAC removed chronic edemaVAC removed chronic edema–– Enhanced formation of granulation tissueEnhanced formation of granulation tissue

Argenta LC. V.A.C: a new method for wound control and treatment: clinical experience.Ann Plast Surg 1997;38:563-76.

Clinical studiesClinical studies

Retrospective study looking at 42 Retrospective study looking at 42 patients patients

Variety of woundsVariety of wounds–– SternalSternal–– SpinalSpinal–– Lower extremityLower extremity

Antony, S. et al, A retrospective study: V.A.C. in the treatment of wounds.J Natl Med Assoc. 2004 August; 96(8): 1073–1077

ResultsResults

Sternal Sternal wounds:wounds:–– All 12 patients with after CABG closed by All 12 patients with after CABG closed by

4 weeks, with average of 12 days4 weeks, with average of 12 days

Lower extremity wounds:Lower extremity wounds:–– 13 patients/14 patients responded to 13 patients/14 patients responded to

therapytherapy

Clinical evidence:Clinical evidence:Decrease in wound sizeDecrease in wound size

Gregor, S. et al. A Vacuum of Evidence, Arch Surg 2008;143:189-196

Comparison StudyComparison StudyBraakenburgBraakenburg’’s studys study

Conventional Conventional Daily dressingDaily dressing Increases in Increases in

nursing nursing interventionsinterventions

Increased Increased discomfortdiscomfort for for patientspatients

Increase length Increase length of hospital stay of hospital stay

VACVAC 3 times a week 3 times a week Lower nursing staffLower nursing staff

costscosts Overall, Pts more Overall, Pts more

comfortable comfortable Decrease length of Decrease length of

hospital stayhospital stay Faster wound Faster wound

healing in patients healing in patients with with Diabetics and Diabetics and Cardiovascular Cardiovascular diseasedisease

Sternal infectionsSternal infections

Retrospective analysis of Retrospective analysis of sternal sternal wound infection wound infection

68 cases 68 cases –– 35 patients could be allocated to the 35 patients could be allocated to the

vacuum group and vacuum group and –– 33 patients to the conventional group wet 33 patients to the conventional group wet

to dry. to dry.

Fuchs, U. Clinical Outcome of Patients With Deep Sternal Wound Infection Managed by VAC Compared to Conventional Therapy

With Open Packing: The Annals of Thoracic Surgery Volume 79, Issue 2, February 2005, Pages 526-531

NOT KCI funded

Sternal Sternal infectionsinfections

End pointsEnd points Time interval from Time interval from sternal sternal infection infection

until freedom of microbiological until freedom of microbiological culturescultures

InIn--hospital stayhospital stay Sternal Sternal status at dischargestatus at discharge Survival ratesSurvival rates

Fuchs, U. Clinical Outcome of Patients With Deep Sternal Wound Infection Managed by VAC Compared to Conventional Therapy With Open Packing: The Annals of Thoracic Surgery Volume 79, Issue 2, February 2005,

Pages 526-531NOT KCI funded

Sternal Sternal infectionsinfections

pp < 0.01< 0.01

pp < 0.01< 0.01

pp > 0.05> 0.05

10 out of 10 out of the 35 the 35 patientspatients

21 out of the 21 out of the 33 patients33 patients

d/c with d/c with an open an open sternumsternum

34 days34 days25 days25 daysinin--hospital hospital staystay

21 days21 days28 days28 daysWound Wound healinghealing

VACVACConventional Conventional dressingsdressings

Sternal Sternal infectionsinfections

Survival rateSurvival rate97% 97% vs vs 74%74%

Clinical studyClinical studyDiabetesDiabetes

Randomized control study Diabetic foot Randomized control study Diabetic foot amputation wound amputation wound

24 patients assigned to NPWT or standard 24 patients assigned to NPWT or standard wound dressingwound dressing

End point was time in reaching 90% of End point was time in reaching 90% of wound granulation. wound granulation.

RESULTS: RESULTS: –– VAC 18.8 +/VAC 18.8 +/-- 6 days6 days versusversus

–– Standard wound care 32.2 =/Standard wound care 32.2 =/-- 13.713.7 Statistically significant difference (P=0.007). Statistically significant difference (P=0.007).

Sepúlveda G, NPWT versus standard wound dressing in the treatment of diabetic foot amputation.A randomized controlled trial, Cir Esp. 2009 Sep;86(3):171-7.

NOT KCI funded

efficacyefficacy

Contraindications to VACContraindications to VAC

Necrotic tissueNecrotic tissue Cancer in woundCancer in wound FistulasFistulas Not on blood vesselsNot on blood vessels

Thoughts on the FutureThoughts on the Future

Health care costHealth care cost Use in emergenciesUse in emergencies

CostCostVuerstaekVuerstaek’’s s studystudy

3881388154525452TotalTotal

124124175175NurseNurse

583583508508PersonnelPersonnel

2391239147704770Bandage Bandage dressingdressing

84784700VAC costVAC cost

VAC n=30VAC n=30Conventional n=30Conventional n=30

P=.001

CostCost

Compared VAC to wet to dry dressing.Compared VAC to wet to dry dressing. VAC had higher material costs. VAC had higher material costs. VAC had VAC had lowerlower number of timenumber of time--

consuming dressing changes consuming dressing changes VAC had VAC had shortershorter duration of therapyduration of therapy Thus VAC and wet to dry therapy Thus VAC and wet to dry therapy

being equally as expensivebeing equally as expensiveMouës CM Bacterial load in relation to VAC wound therapy: a prospective randomized trial.

Wound Repair Regen. 2004 Jan-Feb;12(1):11-7.

Thoughts on the Future of Thoughts on the Future of VACVAC

Health care costHealth care cost

Use in emergenciesUse in emergencies

TraumaTrauma

88 high88 high--energy soft tissue wounds identified energy soft tissue wounds identified in 77 patients in in 77 patients in Balad Balad IraqIraq

Patients treated initially with Patients treated initially with debridement debridement and wound vac placementand wound vac placement

Patients then underwent serial surgical Patients then underwent serial surgical debridement debridement and wound VAC changesand wound VAC changes

The wound infection rate was 0% and The wound infection rate was 0% and the overall wound complication rate the overall wound complication rate was 0%.was 0%. All patients survived and All patients survived and were discharge with closed woundswere discharge with closed wounds

Leininger BE, Experience with wound VAC and DPC of contaminated soft tissue injuries in Iraq. J Trauma. 2006;61(5):1207–11

NOT KCI

referencesreferences

AntonyAntony, S. et al, A retrospective study: clinical experience using vac, S. et al, A retrospective study: clinical experience using vacuumuum--assisted closure in the assisted closure in the treatment of wounds. treatment of wounds. J J Natl Natl Med Assoc. Med Assoc. 2004 August; 96(8): 10732004 August; 96(8): 1073––10771077

Argenta Argenta LC,.LC,.Morykwas Morykwas MJ. VacuumMJ. Vacuum--assisted closure: a new method for wound control and treatment: assisted closure: a new method for wound control and treatment: clinical experience. Ann clinical experience. Ann Plast Surg Plast Surg 1997;38:5631997;38:563--76.76.

Braakenburg Braakenburg A, A, Obdeijn Obdeijn MC, MC, Feitz Feitz R, van R, van Rooij Rooij IALM, van IALM, van Griethuysen Griethuysen AJ, AJ, Klinkenbijl Klinkenbijl JHG. The clinical JHG. The clinical efficacy and cost effectiveness of the vacuumefficacy and cost effectiveness of the vacuum--assisted closure technique in the management of acute assisted closure technique in the management of acute and chronic wounds: a randomized controlled trial. and chronic wounds: a randomized controlled trial. Plast Reconstr SurgPlast Reconstr Surg.. 2006;118(2):3902006;118(2):390--400400

Branski Branski LK, LK, Gauglitz Gauglitz GG, Herndon DN, et al.GG, Herndon DN, et al. A review of gene and stem cell therapy in A review of gene and stem cell therapy in cutaneous cutaneous wound healing.wound healing. BurnsBurns.. Jul 4Jul 4 20082008

Blackburn JH, Blackburn JH, Boemi Boemi L, Hall WW, Jeffords K, Hauck RM, L, Hall WW, Jeffords K, Hauck RM, Banducci Banducci DR et al. NegativeDR et al. Negative--pressure dressings pressure dressings as a bolster for skinas a bolster for skin--grafts. Ann grafts. Ann Plast Surg Plast Surg 1998; 40:4531998; 40:453--7. 7.

Chen SZ, Li J, Li XY, Chen SZ, Li J, Li XY, Xu Xu LS: Effects of vacuumLS: Effects of vacuum--assisted closure on wound microcirculation: an assisted closure on wound microcirculation: an experimental study. experimental study. Asian J Asian J SurgSurg 2005, 28(3):2112005, 28(3):211--77

Fabian TS, Kaufman HJ, Fabian TS, Kaufman HJ, Lett Lett ED, Thomas JB. The evaluation of ED, Thomas JB. The evaluation of subatmospheric subatmospheric pressure and pressure and hyperbaric oxygen in hyperbaric oxygen in ischaemic ischaemic fullfull--thickness wound healing. Am thickness wound healing. Am Surg Surg 2000;66 :11362000;66 :1136--43. 43.

Fuchs, U. Clinical Outcome of Patients With Deep Fuchs, U. Clinical Outcome of Patients With Deep Sternal Sternal Wound Infection Managed by VacuumWound Infection Managed by Vacuum--Assisted Closure Compared to Conventional Therapy With Open PackAssisted Closure Compared to Conventional Therapy With Open Packing: A Retrospective Analysis ing: A Retrospective Analysis The The Annals of Thoracic SurgeryAnnals of Thoracic Surgery VVolume 79, Issue 2olume 79, Issue 2, February 2005, Pages 526, February 2005, Pages 526--531531

Leininger BE, Experience with wound VAC and DPC of contaminated soft tissue injuries in Iraq. J Trauma. 2006;61(5):1207–11

Morykwas Morykwas MJ, MJ, Argenta Argenta LC, SheltonLC, Shelton--Brown EI, Brown EI, McGuirt McGuirt W. VacuumW. Vacuum--assisted closure: a new method for assisted closure: a new method for wound control and treatment: animal studies and basic foundationwound control and treatment: animal studies and basic foundation. . Ann Ann Plast SurgPlast Surg.. 1997;38(6):5531997;38(6):553--562562

Morykwas Morykwas MJ, MJ, Faler Faler BJ, Pearce DJ, BJ, Pearce DJ, Argenta Argenta LC. Effects of varying levels of LC. Effects of varying levels of subatmospheric subatmospheric pressure on pressure on the rate of granulation tissue formation in experimental wounds the rate of granulation tissue formation in experimental wounds in swine. in swine. Ann Ann Plast SurgPlast Surg..2001;47(5):5472001;47(5):547--551551

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