Simplified Negative Pressure Wound

Therapy for Low Resource Settings

Gita N. Mody, M.D., M.P.H.

Danielle R. Zurovcik, Ph.D.

Second WHO Global Forum on Medical Devices

November 24, 2013

Advanced wound care is needed in the

developing world.

The GBD Study 2010, Institute for Health Metrics and Evaluation

NPWT is proved to decrease healing

time.

• Mechanisms

– Reduce edema

– Debridement

– Reduce bacterial burden

– Increase vascularity

– Increase growth factors, fibroblasts

Ad hoc NPWT systems heal wounds

faster than wet to dry dressings.

Perez D., et al. Modern wound care for the poor: a randomized clinical trial comparing the vacuum

system with conventional saline-soaked gauze dressings. American Journal of Surgery, 2010

Simplified Negative Pressure Wound

Therapy was originally developed as a

“DIY” system.

Zurovcik, D. Development of a Simplified Negative Pressure Wound Therapy Device.

Masters of Science in Mechanical Engineering Thesis. MIT. 2007.

We identified early failures during our

pilot phase.

Orgill DP, Zurovcik DR, Mody GN. Reply: Alternative Materials in Vacuum-Assisted

Closure. Plastic & Reconstructive Surgery. 2011; 128(6):785e-786e.

Initial non-integrated tubing failed due

to air leaks.

Dressings need to have integrated

tubes to work with a mechanical drain.

Dressings need to have integrated

joints to work with a mechanical

drain.

11..8

31.7

0

5

10

15

20

25

30

35

40

non-integrated integrated

Ave

rage

NP

WT

Dressing type

Average NPWT duration delivered by dressing type

non-integrated

integrated

Overcoming body surface contours is still necessary

for broad application of sNPWT.

52.7 hours

20.9 hours

33.0 hours

0

10

20

30

40

50

60

easy medium hard

Ave

are

ge

NP

WT

(h

ou

rs)

Wound difficulty

Average NPWT delivered by body surface contour

type

Easy

(flat surface)

Medium

(curved, difficult to reach)

Hard

(joint, movement, fluids)

Anterior/lateral extremity Posterior aspect extremity Sarcum

Abdomen Trochanter Foot

Back Shoulder Heel

p = 0.029

Field observations of dressing

applications identified design targets.

Field observations of dressing

applications identified design targets.

Clinical ProblemsClinical ProblemsClinical Problems

Field observations of dressing

applications identified design targets.

Clinical Problems

Formal Design ProcessFormal Design Process

Field observations of dressing

applications identified design targets.

Engineering SolutionsClinical Problems Engineering SolutionsEngineering Solutions

Field observations of dressing

applications identified design targets.

Engineering SolutionsClinical Problems

Air leak (tube)

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

Clinical Problems

Air leak (tube)

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

Clinical Problems

Air leak (tube)

Air leak (skin)

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Clinical Problems

Air leak (tube)

Air leak (skin)

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Fluid management

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Fluid management

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Shear forces

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Fluid management

Leverage shear forces

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Shear forces

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Fluid management

Leverage shear forces

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Shear forces

Heat, sweat, humidity

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Fluid management

Leverage shear forces

Novel material design

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Shear forces

Heat, sweat, humidity

Field observations of dressing

applications identified design targets.

Engineering Solutions

Integrated tube

System design

Fluid management

Leverage shear forces

Novel material design

Clinical Problems

Air leak (tube)

Air leak (skin)

Maceration of skin

Shear forces

Heat, sweat, humidity

Final

sNPWT

Device

Acknowledgements

• In-country support– Dr. Agnes Binagwaho, Rwandan Minister of Health

• Mentorship– Dr. Robert Riviello, BWH Center for Surgery and Public Health

– Dr. Alex Slocum, Massachusetts Institute of Technology

• Funding – National Institute of Health Grant: R24TW007988

– Center for Integration of Medicine and Technology (Boston)

– MIT Legatum Center

Mechanical NPWT sources are

available but not affordable.

Hutton DW, Sheehan P. Comparative effectiveness of the SNaP™

Wound Care System. Int Wound J. 2011; 8(2): 196-205.

Other mechanical NPWT designs have

limitations.

Webster, R., et. al. Alternative materials in vacuum-assisted closure.

Plastics and Reconstructive Surgery. 2011; 128(6): 784e-53.