Negative Pressure Wound Therapy - Mechanisms of Action and Protecting Exposed Blood Vessels in the Wound Bed

Research output: ThesisDoctoral Thesis (compilation)

Abstract

NPWT has recently been associated with severe complications and bleeding
when used in wounds with exposed blood vessels. The aims of this work were to investigate
the mechanisms of action of NPWT and to explore the possibility of using thin plastic discs
to protect exposed blood vessels in the wound bed during NPWT.
Three different kinds of wounds were created in pigs: 6 cm and 10 cm diameter circular
defect wounds on the back and 6 cm incision wounds in the groin, exposing the femoral
artery. Microvascular blood flow was studied with transcutaneous laser Doppler flowmetry
(LDF), invasive LDF, and thermodiffusion. Femoral artery blood flow was studied with
invasive LDF. Pressure in the wound edge tissue, in the wound cavity and periarterial
pressure was measured with pressure transducers. Wound contraction and wound fluid
removal were also studied.
Tissue pressure 0.1 cm from the wound edge decreased while an increase was found further
(0.5 cm) from the wound edge. Increased tissue pressure is believed to be the result of
wound contraction and wound edge tissue deformation. The use of a small foam wound
filler allowed significant wound contraction, which may result in considerable mechanical
stress. In contrast, gauze or a large foam filler led to less wound contraction, which may be
more appropriate when NPWT causes pain.
Furthermore, NPWT induced a decrease in blood flow 0.5 cm, and an increase 2.5 cm
from the wound edge, with a transition zone at 1 cm. This combination of hypo- and
hyperperfusion may facilitate both oxygenation and stimulate angiogenesis. However,
NPWT should be used with caution in tissues with compromised vascularity due to the risk
of ischemia.
Thin plastic discs of different designs were placed in the wound bed during NPWT.
Femoral artery blood flow and wound bed tissue blood flow decreased when NPWT was
applied, but was restored when a disc was inserted. The key mechanisms of NPWT – i.e.,
pressure transmission to the wound cavity, wound contraction, and wound fluid removal –
were not impaired by the discs. Further development and studies on the possible protective
effects of thin plastic discs used during NPWT are needed before these can be implemented
in clinical practice.

Details

Authors
  • Erik Anesäter
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cardiac and Cardiovascular Systems
  • Surgery

Keywords

  • Negative pressure wound therapy, wounds, complications, experimental surgery, blood flow
Original languageEnglish
QualificationDoctor
Awarding Institution
Supervisors/Assistant supervisor
Award date2015 Mar 20
Publisher
  • Thoracic Surgery
Print ISBNs978-91-7619-103-3
Publication statusPublished - 2015
Publication categoryResearch

Bibliographic note

Defence details Date: 2015-03-20 Time: 13:00 Place: Segerfalksalen, BMC A10, Sölvegatan 17, Lund. External reviewer(s) Name: Kratz, Gunnar Title: MD, PhD Affiliation: Professor of Plastic Surgery, Linköping University, Sweden ---

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Related research output

Anesater, E., Ola Borgquist, Torbrand, C., Roupé, M., Richard Ingemansson, Sandra Lindstedt Ingemansson & Malin Malmsjö, 2013, In : Surgical Innovation. 20, 1, p. 74-80

Research output: Contribution to journalArticle

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