The Effect of Vacuum-assisted Closure on the Tissue Oxygenation of Venous Ulcers: A Pilot Study 

Background. Vacuum-assisted closure (V.A.C.® Therapy, KCI, San Antonio, TX) has been widely used to increase the healing rate of a variety of wounds. It has been hypothesized that one of the actions of VAC is to increase perfusion and subsequent oxygenation of tissue. The aim of the present study was to investigate the effect of VAC therapy on transcutaneous oximetry measurements (TCOM) of skin surrounding chronic venous ulcers.

This was a prospective, experimental pilot study. Patients undergoing compression therapy were recruited from a community wound clinic. All patients had ankle-brachial pressure indices (ABPI) > 0.8. Three TCOM values were taken from around the ulcer and a reference TCOM was taken from the chest. Negative pressure was applied on the ulcer at 125-mmHg continuous subatmospheric pressure and four-layer compression bandaging over the VAC drapes. The duration of the study was 6 days. On day 6, dressings were removed and TCOM was repeated at the same skin sites.

Fourteen of the 17 patients completed the trial. The median age was 73 years (range 49-85). No significant difference was found in oxygen partial pressure pre-and post-VAC therapy around the ulcer site (mean 41.5 mmHg versus 40 mmHg [P = 0.67]). There was a significant difference in TCOM between the reference point and the periwound area (mean 60.5 versus 40 [P < 0.0005]).

This pilot study suggests that VAC therapy does not change oxygen partial pressure around venous ulcers. TCOM of the skin around ulcers were low despite normal ABPIs.