Prospective Randomized Phase II Trial of Accelerated Reepithelialization of Superficial Second-Degree Burn Wounds Using Extracorporeal Shock Wave Therapy

Abstract

As extracorporeal shock wave therapy (ESWT) can enhance healing of skin graft donor sites, this study focused on shock wave effects in burn wounds. A predefined cohort of 50 patients (6 with incomplete data or lost to follow-up) with acute second-degree burns from a larger study of 100 patients were randomly assigned between December 2006 and December 2007 to receive standard therapy (burn wound debridement/topical antiseptic therapy) with (n = 22) or without (n = 22) defocused ESWT (100 impulses/cm at 0.1 mJ/mm) applied once to the study burn, after debridement. Randomization sequence was computer-generated, and patients were blinded to treatment allocation. The primary endpoint, time to complete burn wound epithelialization, was determined by independent, blinded-observer. A worst case scenario was applied to the missing cases to rule out the impact of withdrawal bias. Patient characteristics across the 2 study groups were balanced (P > 0.05) except for older age (53 ± 17 vs. 38 ± 13 years, P = 0.002) in the ESWT group. Mean time to complete (≥95%) epithelialization (CE) for patients that did and did not undergo ESWT was 9.6 ± 1.7 and 12.5 ± 2.2 days, respectively (P < 0.0005). When age (continuous variable) and treatment group (binary) were examined in a linear regression model to control the baseline age imbalance, time to CE, age was not significant (P = 0.33) and treatment group retained significance (P < 0.0005). Statistical significance (P = 0.001) was retained when ESWT cases with missing follow-up were assigned the longest time to CE and when controls with missing follow-up were assigned the shortest time to CE. In this randomized phase II study, application of a single defocused shock wave treatment to the superficial second-degree burn wound after debridement/topical antiseptic therapy significantly accelerated epithelialization. This finding warrants confirmation in a larger phase III trial (ClinicalTrials.gov identifier: NCT01242423).