Cytokines and growth factors in wound drainage fluid from patients undergoing incisional hernia repair.

Knowing the dynamics of growth factor and cytokine secretion within the site of a surgical operation is important, as they play a crucial role in the pathophysiology of wound healing and are a target for modifying the repair response. The aim of this study was to evaluate the production of several cytokines and growth factors in the drainage wound fluid from patients undergoing incisional hernia repair: namely, interleukin (IL)-6, IL-10, IL-1alpha, IL-1 ra, interferon-gamma, vascular endothelial growth factors and basic fibroblast growth factor. Ten female patients with abdominal midline incisional hernia undergoing surgical repair were included in this study. In all cases, a closed-suction drain was inserted in the wound below the fascia and removed on postoperative day 4. Wound fluid was collected on postoperative days 1-4 and the amount was recorded each time. Growth factors and cytokines production was evaluated as the whole amount produced over a 24-hour period. In all patients, the amount of drain fluid from surgical wounds was more copious the first day after surgery, it decreased significantly afterward. The presence of all cytokines was highest on postoperative day 1, decreasing over the following days. More specifically, the production of IL-1 ra, IL-6, IL-1alpha, and IL-10 on postoperative day 1 fell sharply on postoperative days 3 and 4, whereas, after an initial reduction, interferon-gamma showed an increase from day 2 onward. Vascular endothelial-derived growth factor production increased progressively after the operation reaching statistical significance only on day 4. As for basic fibroblast growth factor, it showed an opposite pattern: it was higher on postoperative day 1 decreasing thereafter. This analysis of cytokine and growth factor production in the drain fluid will lead us to a better evaluation of the events that follow a surgical wound and to a better understanding of the healing process.