Researcher Discusses Meta-Analysis Results

In this video, Paul Kim, DPM, MS, discusses the results of his prospective, randomized, multi-center, post-market trial,¹ which compared the effects of negative pressure wound therapy (NPWT) with instillation and dwell with NPWT without instillation therapy in wounds that required operative debridement.

Reference

1. Kim PJ, Lavery LA, Galiano RD, et al. The impact of negative-pressure wound therapy with instillation on wounds requiring operative debridement: pilot randomised, controlled trial. Int Wound J. 2020;17(5):1194-1208. doi:10.1111/iwj.13424

Transcript:

Paul Kim: Just as a background for people who don't understand how meta-analysis and systematic reviews are performed. Essentially, it's a way to pool the data from multiple different comparative studies, and that's what we did with this, with this paper.

And essentially start with a literature search, looking at papers that compare one thing versus another. And the competitor, in this case, was a multiple of different types of therapies, including standard negative-pressure packing, and so on and so forth. All compared with instillation therapy.

Once you pool those papers together, then you analyze the outcomes and try to find similar outcomes that cross those studies. We found some very interesting results.

Number one is the number of OR debridement. You know, if you discount though, the, the prospective randomized controlled study, which, as, as I said, had some, had some flaws in the design, there was a decrease in amount in the number of OR debridement required for an infected wound in the group that got instillation therapy.

The, the time to final surgical procedure was also statistically significant, meaning, when are you done with that wound? And why that measure is very important is the fact that when you look at length of hospitalization, which is what many people do, and, I, and I have too in, in several of my publications, that's important.

But we know length of hospitalization is driven by multiple factors, including finding a place for the patient to be discharged to, there may be some other medical problems that the patient is resolving while in the hospital that may be completely unrelated to the wound.

So the wound itself that the, the, the number of times the patient's required to go to the OR until it's deemed ready for closure, coverage, or discharge, is a very important, uh, variable. And that was found to be significantly decreased as far as the time ready for the time to final surgical procedure in the group that got instillation therapy.

The other important aspect of this is length of therapy itself. So one of the things that, that I don't want to happen is to promote a therapy that actually increases the overall healthcare cost to a system if you can decrease the length of therapy days utilized.

And that's very important. That's a cost-saving. It's better for the patients, it's better for everyone. And the length of therapy days was also statistically significantly different, meaning the group that got instillation was actually lower than that, that got other types of therapies, including standard negative-pressure wound therapy.

The other thing that we, we found, which was now been very consistent in all, a lot of publications including in vivo studies, in vitro studies, and clinical trials, is there was a significant decrease in bacterial counts. And that's very important for as far as wound health is concerned.

The length of hospitalization, however, was not statistically significant, but it did trend in that direction. In fact, it was, it was the, the P-value was .06, so it's, it's very close to being statistically significant.

When you look at meta-analysis, you have to be very careful because it's pooling of all these studies with various different study designs. So it's never very clean. That's true of all meta-analysis, regardless of what, what space that you're, you're looking at.

Especially in the wound space, there is a lack of meta-analysis that's being performed. And the ones that have been performed on certain dressings, for example, uh, are inconclusive in their findings because of the wide heterogeneity that exists in the trials that they looked at and they pooled together.

And they, they're very rare to be performed and the analysis has not been favorable, necessarily to the therapy that they're studying. So this was unique in, in, in a variety of ways.

The other finding that is not talked about so much about this in this meta-analysis, but for me is very interesting and important, and that's the complications that were reported in each of those two groups. The control group, by the way, had 481 subjects in that group versus the instillation group had a total 410 subjects.

Now, those are pooled subjects from multiple different studies. This is not just from a single study. And they report-, and we reported that the, the number of subjects that, that experienced the complication was about 9 percent in the instillation group versus that of the control group, which includes standard negative-pressure, it was about 18 percent, so double.

So I think that's an, a very important thing because people are worried about things that are, uh, that may, uh, cause problems with the patient using instillation therapy, like mass aeration.

You know, that's one of those things that people worry about that happen in the higher frequency and we just don't see that as being statistically significant about infection and those dehiscence, and all those things are important as well.