Real World Use: Effect of Collagen and Early Initiation of Negative Pressure Wound Therapy on Wound Surface Area Reduction in Chronic Wounds

Collagen is thought to jump-start the chronic wound by inactivating the excessive matrix metalloproteinases. Early initiation of negative pressure wound therapy (NPWT) has also been previously shown to reduce the number of days to reach 75% wound surface area reduction (WSAR) in chronic wounds. The purpose of this study was to examine the effect of collagen and early NPWT initiation on the time to 75% WSAR in chronic wounds in wound care clinic (WCC) patients. We retrospectively examined US Wound Registry data (de-identified) on a total of 1,187 chronic wounds (diabetic foot, pressure, and venous ulcers) from 984 patients treated who received early NPWT with or without Collagen in 51 outpatient WCCs. Early NPWT initiation was defined as treatment initiated within 30 days of the first WCC visit. Treatments were classified as early NPWT/no collagen (n=864), Collagen before early NPWT (n=52), early NPWT then Collagen without NPWT (n=194), and early NPWT then Collagen+NPWT (n=77). Time-to-WSAR was defined as the number of days from first visit to first date WSAR reached 75% after NPWT initiation. Kaplan-Meier curves were used to estimate median days to 75% WSAR. Cox proportional hazard regression was used to adjust for initial size and age at time of first visit. Median days to 75% WSAR for early NPWT/no Collagen, Collagen before NPWT, early NPWT then Collagen without NPWT, and early NPWT then Collagen+NPWT were 100.6, 119.4, 90.5, and 76.3, respectively (p=0.0087). Hazard ratio for early NPWT then Collagen+NPWT was 1.52, indicating it was 52% more likely to reach 75% WSAR compared to NPWT only. For chronic wounds with early NPWT initiation, the addition of collagen in conjunction with NPWT was associated with a significantly decreased time to WSAR compared to NPWT alone. Further studies are warranted to determine appropriate timing of Collagen and NPWT.