Impact of preoperative local water-filtered infrared A irradiation on postoperative wound healing: a randomized patient- and observer-blinded controlled clinical trial.

Abstract

In addition to a preoperative antibiotic single-shot prophylaxis, we tested the impact of a one-time preoperative water-filtered infrared A irradiation (wIRA) on postoperative wound healing of patients. wIRA improves wound healing in postoperative settings. A total of 400 consecutive patients undergoing gastrointestinal surgery were randomly assigned to the treatment group (A) or placebo group (B). We applied wIRA for 20 minutes while patients were prepared for surgery. Patients and observer were blinded to group assignment. Primary endpoints were surgical site infections (SSIs), wound healing, and rate and level of pain within 30 days after surgery. Primary efficacy analysis was carried out on the basis of an intention-to-treat (ITT) population and a full-analysis set (FAS). Missing values of primary outcome variables were considered as SSIs and maximum pain levels in the ITT analysis, respectively. The incidence of SSI was 9 of 178 patients (5.1%) within group A compared with 22 of 182 (12.1%) within group B [P = 0.018; relative risk (RR) = 0.42; 95% CI: 0.18-0.93]. ITT: 32 of 200 (16%) SSIs occurred within group A and 39 of 200 (20%) within group B (P = 0.248) with an RR of 0.74 (95% CI: 0.43-1.28). The wIRA group showed lower postoperative pain at both the ITT (P = 0.092) and the FAS analysis (P = 0.045). This trial indicates a clinically relevant benefit of one-time application of preoperative wIRA as a supportive addition to prophylactic antibiotics. wIRA contributes to both reduced SSI rates and postoperative pain but also effectively decreases morbidity and related expenses in the health care system.