Irrigation is Key for Effective Negative Pressure Wound Therapy, Study Says

The latest issue of Wound Repair and Regeneration (November/December) featured the first randomized controlled study to compare the efficacy of negative pressure wound therapy (NPWT) with and without simultaneous irrigation. Researchers found that both kinds of NPWT reduced the wound size at a far greater rate than the control therapy. In addition, results showed NPWT with simultaneous irrigation further reduced the amount of bioburden compared to wounds treated with NPWT alone.

The study also analyzed the effects of different irrigation solutions on wound healing and bioburden reduction. Normal saline and Polyhexanide biguanide, commonly known as the antimicrobial Prontosan, were evaluated as irrigant solutions, and both improved bioburden over NPWT alone. Notably, normal saline was found to be just as effective as the antimicrobial, Prontosan.

“Our preclinical research affirmed our hypothesis that irrigation therapy is both an effective tool for wound healing and reducing bioburden,” said Kathryn Davis, Ph.D., of the department of plastic surgery at University of Texas Southwestern Medical Center and the lead author of the study. “What makes this data so exciting from a clinical perspective is that irrigation therapy showed such dramatic results in healthy pigs, which are highly resistant to infection. These results are likely understating the full healing potential of irrigation therapy for chronic wounds in patients with multiple comorbidities. The results beg for more clinically focused research and we’re looking forward to putting our methodology to the test in a clinical trial in the coming months.”

For the study, researchers established a rigorous porcine methodology where full thickness excisional wounds were placed on six different pigs. Each wound was inoculated with approximately 500 colony-forming units of Pseudomonas aeruginosa (the bioburden) and left to incubate for three days before treatment began, thus allowing the colonies to establish before applying the different therapy conditions. This technique provided a more rigorous assessment of bioburden reduction than applying the therapies immediately after inoculation. Wounds were then treated for 21 days of therapy with either the control (no therapy), NPWT alone or NPWT with simultaneous irrigation. Normal saline or Prontosan, at low or high flow rates, were used in irrigation. NPWT was administered using Pompano Beach, Fla.-based Innovative Therapies Inc.’s (ITI) Quantum NPWT system at -125 mm Hg (inches of mercury) of pressure. At day 21, NPWT and all irrigation conditions had wound areas that were 50 percent smaller than the control wound areas.

“We’re extremely encouraged with the study results that demonstrate Quantum’s ability to heal wounds faster and reduce bioburden,” said Sandra Berriman, Ph.D., vice president, medical affairs at ITI. “We know that chronic conditions, such as non-healing wounds, are a tremendous burden on both the patient and the healthcare system. At ITI, we believe it’s important to support research that will not only continue to establish best practices, but also suggest new science and evaluate the value of wound care technology. This research is part of an on-going series of scientific studies currently being conducted by ITI to demonstrate the clinical and economic benefits of Quantum.

“More research needs to be done, but irrigation therapy combined with NPWT as a standard is likely where wound care treatment is headed,” Davis continued. “The use of irrigation therapy could open up many different scenarios to allow administration of other therapeutic solutions and may become the new standard in the not so distant future.”