Utility of indigo carmine angiography in patients with critical limb ischemia: Prospective multi-center intervention study (DIESEL-study)

Objectives To assess the efficacy of indigo carmine angiography for wound healing after successful below-the-knee intervention in patients with critical limb ischemia (CLI). Methods A multi-center prospective intervention study was conducted. Fifty-four limbs of 53 patients in Rutherford categories 5 and 6 underwent endovascular therapy (EVT). After successful EVT, 5 mL of indigo carmine was injected through a catheter at the distal popliteal artery and color changes in the foot were evaluated. The results of indigo carmine angiography were divided into three groups: In type I, the color change of the wound was deeper than the surrounding tissue; in type II, the change in wound color was similar to the surrounding tissue; and in type III, no discoloration of the wound was observed by the indigo carmine. Results The wound healing rates at 3 months were 78% (25/32) for type I, 70% (7/10) for type II, and 42% (5/12) for type III (P for trend = 0.025). Indigo carmine angiography-related complications were not seen. Conclusion Indigo carmine angiography was found to be a safe and useful procedure to provide visual information on foot perfusion. This dye coloring method demonstrated that after successful angioplasty, the perfused area was made visible at the microcirculation level. Indigo carmine angiography can thus be considered an important predictor for wound healing by EVT in patients with CLI.