Microcirculatory investigations to determine the effect of spinal cord stimulation for critical leg ischemia: The Dutch Multicenter Randomized Controlled Trial

Purpose: Patients with non-reconstructable critical limb ischemia generally undergo medical treatment only to prevent or postpone amputation. There is some evidence that spinal cord stimulation (SCS) stimulates ischemic wound healing. Thus, this could benefit limb survival through improved skin perf usion. We investigated the effect of SCS versus conservative treatment on s kin microcirculation in relation to treatment outcome in patients with non- reconstructable critical limb ischemia. Methods: Standard medical treatment plus SCS was compared with only standar d medical treatment in a multicenter randomized controlled trial comprised of 120 patients with surgically non-reconstructable chronic rest pain or ul ceration. We investigated skin microcirculation by means of capillary micro scopy, laser Doppler perfusion, and transcutaneous oxygen measurements in t he foot. The microcirculatory status just before treatment was classified i n three categories (poor, intermediate, and good) and was related to limb s urvival after a minimum follow-up period of 18 months. Results: Clinical parameters, peripheral blood pressures, and limb survival rates showed no significant differences between the SCS and standard group s during the follow-up period. Ln both treatment groups, amputation frequen cy after 18 months was high in patients with an initially poor microcircula tory skin perfusion (SCS 80% vs standard treatment 71%; NS) and low in thos e with a good skin perfusion (29% vs 11 %, respectively; NS). In patients w ith an intermediate skin microcirculation amputation, frequency was twice a s low in patients additionally treated with SCS as in the standard treatmen t group (48% vs 24%; P =.08). Ln these patients, microcirculatory reactive hyperemia during the follow-up period reduced in the standard group but not in the SCS group (P < .01). Conclusion: Selection on the basis of the initial microcirculatory skin per fusion identifies patients in whom SCS can improve local skin perfusion and limb survival.