The effect of vacuum-assisted closure on lymph vessels in chronic wounds

Chronic wounds come in various forms and result from a multitude of factors that play a detrimental role in the wound-healing process. A breakthrough in wound management came with the introduction of vacuum-assisted closure (VAC). Although numerous papers have been published suggesting that VAC is based upon its unique ability to accelerate the rate of granulation tissue production, enhance angiogenesis and remove excess chronic wound fluid, no attempts have been made to investigate its effect on lymph vessels.

From April 2005 to April 2006, 80 patients with chronic wounds were treated with VAC therapy and prospectively studied. The parameters included: the length of VAC treatment, the number of dressing changes, the number of days of hospitalisation and immunocytochemical lymphatic vessel density assessments.

Lymph vessel proliferation was noted in all types of wounds, up to the first dressing change, but as VAC therapy continued it was apparent that patients exhibiting the same type of wounds did not exhibit the same results. Additionally, the duration of VAC therapy, dressing changes and average number of days of hospitalisation were significantly less in some cases but also prolonged in others.

VAC therapy seems to be inducing morphological and quantitative alterations on the lymph vessel network in a wound. The effect of VAC therapy varies greatly depending on the presence of underlying diseases and risk factors impairing wound healing. An increase in the density of lymph vessels manifested histologically correlates with a better clinical outcome, in terms of healing rates and hospitalisation time.