A PRELIMINARY-STUDY TO EVALUATE THE EFFECT OF PULSED RADIO-FREQUENCY FIELD TREATMENT ON LOWER-EXTREMITY PERI-ULCER SKIN MICROCIRCULATION OFDIABETIC-PATIENTS

To determine the potential effects of pulsed radio frequency field (PR FF) treatment on peri-ulcer microcirculation, this preliminary study m easured laser Doppler (LD) red blood cell (RBC) perfusion, volume and velocity, and skin temperature in 15 subjects with diabetes (DM), each of whom had an ulcer on the foot or toe of one limb for at least eigh t weeks duration. These measurements were made at a peri-ulcer site an d contralateral nonulcerated limb site prior to and at the end of a si ngle 45 minute PRFF treatment protocol. The contralateral site was use d to control for any systemic changes that might occur during treatmen t interval unrelated to the treatment itself. All subjects had DM grea ter than or equal to five years and nine of these had lower extremity arterial disease in the ulcer bearing limb as judged by noninvasive va scular testing which included measurements of ankle brachial indices ( ABI) and total leg pulsatile flow measured by magnetic resonance flowm etry. The overall data on this initial group of patients showed that a t the peri-ulcer site, the single treatment produced an increase in LD perfusion which occurred mainly due to an increased volume component; there was no significant increase in any LD parameter at the contrala teral control site nor was there an increase in skin temperature at ei ther site. The LD increase occurred even though the peri-ulcer pretrea tment perfusion and volume were much greater than at the contralateral control site. This suggests peri-ulcer vasodilation, perhaps in respo nse to ulcer metabolic needs. Nonetheless, PRFF still caused a further increase in perfusion. Since volume component of the LD measurement i s related to the microvessel number with active RBC flow, its increase due to PRFF suggests either further arteriolar dilation and/or select ive recruitment of previously non-perfused vessels. These preliminary findings may suggest that if resting perfusion is marginally inadequat e to promote timely ulcer healing, the incremental perfusion might pot entially aid the healing process. More work to specifically relate PRF F treatment to perfusion changes and ulcer healing outcomes is clearly indicated.