Brief discussion about VAC AND Advances

1. NEGATIVE PRESSUE WOUND THERAPY
SKIN SUBSTITUES
DR MANO ANANTH AB
PG IN PLASTIC AND RECONSTRUCTIVE SURGERY
CHENGALPATTU MEDICAL COLLEGE

2. NPWT
Use of a porous
sponge within the
wound, covered by an
airtight occlusive
dressing to which
vaccum is applied

3. HISTORY
In 1550 BC
• Eber papyrus – ‘cupping’
• Curcurbita - fruit shell
To create suction
• Heat the air in cup  cooled suction
• Hole in the cup  suction applied  closed with
wax
• Applied over intact skin
• In 1000 BC - china
• In 400 BC - Hippocrates – structural problems

4. HISTORY - CUPPING
• CUPPING DEVICE – Animal horn, bamboo, wood,
copper, bronze, pottery and glass.
Chinese cupping
• ‘’realign and balance the flow of one’s vital
energy or life force known as chi along meridians
,which are influence point for internal organs’’

5. HISTORY - CUPPING
• Wet cupping
Skin is scraped or puntured for the
toxins to escape
Cupping massage –
• Specialised slave is applied pulls
with large massage cupping glass
with round edges in slow even
movements
• For soft tissue only
• local blood flow stimulation

6. HISTORY- PHYSIOLOGY
Early 1890s - Prof. August Bier of Germany
• Hyperemic treatment
• In intact skin
• Inducing benefical inflammation against invasion
In 1908 Drs willey mayer , victos schmieden
• First documented apparatus – specially designed
suction glass
• Subatmospheric pressure to skin wound

7. HISTORY
• Bier assistant – Dr.E.klapp – patented –
KLAPP CUP – local inflamamtion and abscess
• JUNOD’S BOOT Victor T Junod ( 1809-1881 )
Airtight case  air is exhausted

9. HISTORY
• 1952 German patent
• Absorbent tampons – natural sponge, rubber
sponge, foam rubber,cellulose sponge ,gauze,
cotton
• 1971 Atmos fritzsching patent use of vaccum
pump, cathetor cannula for intermittent
suction
• 1986-1991 – Russians – kremlin papers – on
open wounds

10. HISTORY
• In 1997 – VAC - vaccum assisted closure –
kinetic concepts.inc (KCI)
• Application of subatmospheric pressure
• Polyurethane sponge – 48 hours
• 2004 – KREMLIN KIT – Blue sky medical

12. SCIENCE OF NPWT
IDEAL GAS LAWS
• Boyle’s law
• Poiseuille’s law

13. BOYLE’S LAW
P V = k T
• V – volume of gas
• T - temperature
• P – pressure exerted in a closed environment
• K - Constant
• At constant temperature , volume is indirectly
proportional to pressure
• Decreased volume  increased pressure

14. POISEUILLE’S LAW
• Calculation of the rate at which an
incompressbile viscous fluid flows through an
cylindrical pipe
• Flow = internal diameter / viscosity ( contact
layer )
• Increased viscosity  decreased flow
• Increased diameter increased flow
• Pump should be placed at the patient level

15. PATHOPHYSIOLOGY
P – hydrostatic pressure  - oncotic pressure
Kf – filitration coefficent - reflection coefficient
Intesitital fluid
Capillaries PC
Pif
𝐽𝑉 = 𝑘𝑓 𝑃𝑐 − 𝑃𝑖𝑓 −  ( 𝑐 − 𝑖𝑓)
c
if

17. PATHOPHYSIOLOGY
• Negative pressure  physical force of
compression against the blood vessels(
starling forces )
• Prevent fluid from leaking out
• Pushing fluid back to capillaries of the tissues
that already leaked

18. PATHOPHYSIOLOGY
Regulating inflammation
 Removal of exudates - edema
• Reduce lactic acid – anaerobic
metabolism ( responsible for
inflammation and sequelae )
• Decreased pain
• Overall decrease INDURATION

19. PATHOPHYSIOLOGY – HYPEREMIC THEORY
Hyperemic
Changes in
microcirulation
Normal
oxidation
reduction
Normal pH
(Normal or
weak
alkaline)
Detrimental
for
microbes
Increased
lymphocytes
Phagocytosis Autolytic
debridement

20. PATHOPHYSIOLOGY
Suction and compression deforms cells
Changes in expression of IEG genes
Increased cellular proliferation and
protein synthesis
Dynamic neutrophilic reaction , prevent
denaturation of collagen
Degenerarion  Restoration phase

21. SUMMARY
• Increase blood flow in existing vessels
• Promote angioneogeneis  granulation tissue
• Bring oxygen, nutrients and new growth factors
• Removes edema
• Maintain moist wound
• Compression effect
• Kills bacteria
• Prevent denaturation of collagen

23. PATHOPHYSIOLOGY – MILLER TECHNIQUE
• Non contact method
Physiological principle
• Every action has an equal and opposite reaction to
maintain homeostasis
• Eg: Bowel ,ureter , diaphragm, cardiac contraction
and relaxation
• Negative pressure – need complete relaxation to
rejuvenate

24. METHOD
• Current gauze dressing change every 24-72
hours
• Pressure (- 70 to – 125 mmHg )
• Suction duration varies in different studies

25. CONTRAINDICATIONS
• Malignancy
• Ischemic wounds
• Badly infected wound with inadequate
debridement

26. IDEAL
• Doesn’t degrade
• Allow real time visualization
• Ability to maintain seal in various conditions
• Support skin during sweating and being
friable

27. FUTURE
• Visual data
• Numericals about wound drainage
• Status of dressing
• Chemical profile
• Functional parameter of pump

28. SKIN SUBSTITUTE

31. SKIN SUBSTITUTE
• Replace the function of skin
• To close the wound
• Eliminate pain and promote wound healing
• Eliminate the need for SSG
• Provide epidermal and dermal analogues

32. TYPES
Component
• Cellular (cultured )
• Acellular
Source
• Human ( Auto / Allogenic )
• Non human
Xenograft – Bovine, procine, murine
• Synthetic
• Combined

33. TYPES
Layer to be subtituted
• Epidermal
• Dermal
• Dermoepidermal
Duration
• Temporary -
• Permanent

34. DURATION
TEMPORARY
SINGLE
NATURAL
MINOTIC
MBRANE
POTATO PEEL
SYNTHETIC
POLMER SHEET,
FOAM, SPRAY
DOUBLE LAYER
TRANSCYTE
DURABLE
EPIDERMAL
EPICELL
DERMAL
DERMAL MATRIX
ALLODERM
KOLLAGEN
BIOBRANE
TRANSYTE CHITODERM
DERMOEPIDERMAL
ORCEL APLIGRAF
INTEGRA LASER SKIN
HYALOGRAFT

35. HISTORY
• 1975 – Rheinwald and Green – composite
Isolated epidermal keratinocytes,
cultured invitro with mouse fibroblast
 large sheet of cultured epithelium
• 1981 – 0’ connor – Autologous keratinocyte
sheets

36. SKIN SUBSTITUTES
EPIDERMAL
• Epicell ( Epidermal )
• My skin ( Epidermal )
• Cryoskin ( Epidermal )
• Laser skin ( Epidermal )
• Aminiotic membrane
• Potato peel
DERMAL
• Alloderm ( dermal)
• Biobrane ( dermal )
• Dermagraft ( dermal)
• Chitoderm ( dermal )
• Transcyte ( dermal )
COMPOUND
• Hyalograft/ hyalomatric
PA ( compound )
• Integra ( compound )
• Apligraf ( compound )
• Orcel ( compound )

37. EPIDERMAL SUBSTITUTES

38. EPICELL
• Epidermal / cellular
• Deep dermal / full thickness burns
• Life saving – mortality ( 90 % vs 37.5 % )
• TSA > 30%
• Keratinocyte from uninjured skin cultured (16-21days )
• 2-8 cell layer / multiple 10000 times
• Contain murine cells  risk of infection ( patient should not
donate )
Petroleum gauze
Cultured keratinocytes + murine cells 2-8 cell layers

39. MY SKIN
• Autologous
• Cell suspension delivered as spray
• Keratinocytes with sillicone support and
acrylic plasma polymer layer
CRYOSKIN
• Similar – allogenic
• Stored in vapour phase of liquid nitrogen

40. LASER SKIN
• Proliferation of keratinocytes
• Biocompatibility
• Scleroderma ulcer
• Deep burns
• Good graft take LASER MICRO PERFORATED
HA + BIOMATERIAL SCAFFOLD + KERATINOCYTES

41. DERMAL SUBSTITUES

42. BIOBRANE
• Acellular, dermal substitute
• Composite , temporary cover, nylon with collagen peptides
• Protective cover for meshed autografts
• Partial thickenness burns, C/I – Full thickness burns
Thin silcone membrane
Nylon mesh + collagen peptides
Type 1 procine Collagen coating

43. BIOBRANE

44. DERMAGRAFT
• Dermal substitute
• Collagen matrix growth factors, protein
GAGs
• DFU - Early cases , heals in 12 weeks
Non porous collagen ge
Bioabsorable polyglactin scaffold + fibroblast+ECM

45. CHITOSAN
• Polysaccharide – outer skeleton of shell fish
• Self adhesive dressing pad
• Burns, abrasions, bed sore
• Haemostasis – non specific binding with cell
membrane
• Antibacterial
Chitosan
Polyurethane
Polyvinyl
alcohol

46. TRANSCYTE
• Temporary / Dermal substitute
• Mid dermal / partial thickeness bubrns
• Better than conventional
• Synthetic / bilayered
• Contains collagen, GAGs ,growth factors
Thin silicone layer
Knitted nylon scaffold + stem cell

47. HYALOGRAFT / HYALOMATRIX PA
• Hyalouronic acid esterification + benzyl
alcohol
• Forms – meshes, non woven textiles,
perforated membrane
Outer silicone layer – PA type
HA + benzyl alcohol + fibroblast / keratinocytes

48. DERMO-EPIDERMAL SUBSTITUES

49. APLIGRAF
• Cellular / allograft / bilayered / shelf life 10 days
• Stored in polyethylene, agarose nutrient medium
• Fibroblast/ keratinocytes from neonate foreskin cultured
• Fibroblast seeded in collagen sponge ( 6 days )
• Produce human matrix layer
• Later kerantinocytes seeded on day 6 ( 4days incubation )
• Incubated in air 10 days - maturation
Cultured Fibroblast + collagen sponge
Polyurethane
Epidermal layer – cultured keratinocytes

51. INTEGRA
• Gold standard for dermal substitute therapy
• Bovine type 1 collagen copolymer with GAG
• Long shelf life
• 15-20 days  Neodermis
• Low immunogenic
• Better cosmetic with less scarring
Epidermal - Polysiloxane layer
Bovine type 1 collagen+ dermal chrondroin sulfate

52. ORCEL
• Dermo – epidermal
• Cellular / allograft
• Provide cytokine / growth factors
• Dystrophic epidermlysis bullosa
• Full / Partial thickness
• Reduce scarring
• Condition wound for grafting
Non porous collagen ge
Cultured keratinocytes
Cultured fibroblast + bovine 1 collagen sponge

53. INTEGRA AND HYALOMATRIX
Integra
• Colour
• Elastoproperty
• Better cosmesis
Hyalomatrix
• Hydration
• Transepidermal
regulation
• ECM regulation
• Neoangiogenesis

54. IDEAL SUBSTITUE

55. IDEAL SUBSTITUE

56. FUTURE
• Nanoscaffold
• Gene modified skin substitute
• Foetal wound heals without scarring 
Scarless healing

57. THANK YOU