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What is negative pressure wound therapy (NPWT)?

Understand how NPWT works, and the potential benefits to chronic, open acute, and post-surgical wounds

Suitable for use on various acute and chronic wounds, and closed surgical incisions, NPWT dressings seal the wound and are connected to a pump (the source of the vacuum) to deliver negative pressure. The pressure over the wound is lower than atmospheric pressure - helping to draw fluid from the wound and pull the edges of the wound together.

NPWT pumps and dressings are available in various traditional and single-use canister-free formats, depending on patient needs.

Why use NPWT dressings?

When compared to standard care alone, NPWT can help (depending on wound type):

  • Promote granulation tissue formation and increase perfusion1
  • Reduce haematoma and seroma formation2-4
  • Protect wounds from the outside environment
  • Reduce oedema4-6 and promote moisture balance within the wound bed7-10
  • Reduce lateral tension,11 with the potential of increasing tensile strength2,3
  • Reduce the incidence surgical site complications, such as infection12,13
  • The progression of acute and chronic wounds, and closed surgical incisions12-15

NPWT may not be suitable for all patients, and must always be used according to clinician guidance and local protocols.

Learn more about the clinical benefits of NPWT.


How does NPWT work?

Watch these brief animations to learn how NPWT works:

On closed surgical incisions*



On open wounds*


Read a EWMA document on the challenges and perspectives of NPWT


Is NPWT the same as vacuum-assisted closure (VAC)?

In certain regions, NPWT is otherwise known as wound Vacuum-Assisted Closure (or wound VAC), but they have the same overall mechanism of action and work on the same physiological principles. NPWT and wound VAC are essentially the same, albeit described using different terms.

NPWT [and wound VAC] were previously referred to as Topical Negative Pressure (TPN), although this term is no longer widely used.


Which wound types are suitable for NPWT?

NPWT has demonstrated clinical efficacy on a number of acute and chronic wounds, and closed surgical incisions:

wounds that are suitable for NPWT or wound VAC 

How to choose the right NPWT option

To help clinicians optimise potential clinical benefits, we’re helping to cut through the complexity of NPWT. See below for guidance on which Smith+Nephew solution to use:

how to choose the right NPWT dressing or wound VAC 
Find out more by visiting:

RENASYS Negative Pressure Wound Therapy System
PICO Single Use Negative Pressure Wound Therapy System


Need help?

For further information and guidance on the use of NPWT, or for help choosing the right solution, please contact us here.


*As demonstrated using the PICO Single Use Negative Pressure Wound Therapy System.

For detailed product information, including indications for use, contraindications, precautions and warnings, please consult the product’s applicable Instructions for Use (IFU) prior to use.

Malmsjö M, Huddleston E, Martin R. Biological effects of a disposable, canisterless negative pressure wound therapy system. ePlasty. 2014;14:e15.
2. Meeker J, Weinhold P, Dahners L. Negative pressure therapy on primarily closed wounds improves wound healing parameters at 3 days in a porcine model. J Orthop Trauma. 2011;25:756-761.
3. Suh H, Lee AY, Park EJ, Hong JP. Negative pressure wound therapy on closed surgical wounds with dead space: animal study using a swine model. Ann Plast Surg. 2016;76:717-722.
4. Kilpadi DV, Cunningham MR. Evaluation of closed incision management with negative pressure wound therapy (CIM): hematoma/seroma and involvement of the lymphatic system. Wound Repair Regen. 2011;19:588-596.
5. Eisenhardt SU, Schmidt Y, Thiele JR, et al. Negative pressure wound therapy reduces the ischaemia/reperfusion-associated inflammatory response in free muscle flaps. J Plast Reconstr Aesthet Surg. 2012;65:640-649.
6. Niimi Y, Mori S, Takeuchi M. A new procedure for wrapped-negative pressure wound therapy for congestion after arterialized venous flap surgery. Clin Med Insights Case Rep. 2017;10:1179547617747279.
7. Dunn R, Hurd T, Chadwick P, et al. Factors associated with positive outcomes in 131 patients treated with gauze-based negative pressure wound therapy. Int J Surg. 2011;9(3):258-262.
8. Young SR, Hampton S, Martin R. Non-invasive assessment of negative pressure wound therapy using high frequency diagnostic ultrasound: oedema reduction and new tissue accumulation. Int Wound J. 2013;10(4):383-388.
9. Kamolz LP, Andel H, Haslik W, et al. Use of subatmospheric pressure therapy to prevent burn wound progression in human: fi rst experiences. Burns. 2004;30(3):253-258.
10. Birke-Sorensen H, Malmsjo M, Rome P, et al. Evidence-based recommendations for negative pressure wound therapy: treatment variables (pressure levels, wound fi ller and contact layer)--steps towards an international consensus. J Plast Reconstr Aesthet Surg. 2011;64 Suppl:S1-16.
11. Loveluck J, Copeland T, Hill J, Hunt A, Martin R. Biomechanical modeling of the forces applied to closed incisions during single-use negative pressure wound therapy. ePlasty. 2016;16:e20.
12. Forlee M, van Zyl L, Louw V, Nel J, Fourie N, Hartley R. A randomised controlled trial to compare the clinical efficacy and acceptability of adjustable intermittent and continuous Negative Pressure Wound Therapy (NPWT) in a new portable NPWT system. Paper presented at: EWMA; 2018; Krakow, Poland.
13. Saunders, C., Buzza, K. and Nherera, L. 2019. A single use negative pressure system reduces surgical site complications compared with conventional dressings in closed surgical incisions: a systematic literature review with metaanalysis. Poster presented at the European Wound Management Association annual meeting, June 5-7, 2019, Gothenburg, Sweden.
14. Dowsett C, et al. Use of PICO to improve clinical and economic outcomes in hard-to-heal wounds. Wounds International. 2017;8, p53–58.
15. Kirsner R, et al. A Prospective, Randomized, Controlled Clinical Trial on the Efficacy of a Single-use Negative Pressure Wound Therapy System, Compared to Traditional Negative Pressure Wound Therapy in the Treatment of Chronic Ulcers of the Lower Extremities. Journal of woundcare and regeneration. May 2019.

Watch a webinar hosted by Dr Hurd and Dr Kirsner