Prediction of imminent amputation in patients with non-reconstructible leg ischemia by means of microcirculatory investigations

• Published in: Journal of vascular surgery Vol. 30; no. 1; pp. 114 - 121
• Main Authors: Ubbink, Dirk Th, Spincemaille, Geert H.J.J., Reneman, Robert S., Jacobs, Michael J.H.M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Mosby, Inc 01.07.1999; Elsevier
• Subjects: Aged; Amputation; Biological and medical sciences; Blood Gas Monitoring, Transcutaneous; Female; Follow-Up Studies; Foot - blood supply; Humans; Ischemia - diagnosis; Ischemia - surgery; Laser-Doppler Flowmetry; Leg - blood supply; Male; Medical sciences; Microcirculation - physiology; Predictive Value of Tests; Prospective Studies; Skin - blood supply; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Time Factors; Vascular surgery: aorta, extremities, vena cava. Surgery of the lymphatic vessels; Vascular disease; Human; Microcirculation; Treatment; Ischemia; Surgical amputation; Surgery; Lower limb; Cardiovascular disease; Predictive factor
• ISSN: 0741-5214; 1097-6809
• DOI: 10.1016/S0741-5214(99)70183-7

Purpose: We investigated the usefulness of skin microcirculatory investigations to predict imminent major amputation in patients with non-reconstructible critical limb ischemia. Methods: One hundred eleven patients with non-reconstructible chronic rest pain or small ulcers and an ankle blood pressure of 50 mm Hg or less or an ankle-to-brachial pressure index of 0.35 or less were included. Nailfold capillary microscopy (CM; big toe, sitting), transcutaneous oxygen pressure (TcpO 2; forefoot, supine; 44°C), and laser Doppler perfusion measurements (LD; pulp of big toe, supine) were performed at rest and during reactive hyperemia. Patients were classified according to their skin microcirculatory status just before the start of the treatment in three groups: those with a “good,” “intermediate,” or “poor” microcirculation, according to a combination of predefined cutoff values (Poor: capillary density less than 20/mm 2, absent reactive hyperemia in CM and LD, TcpO 2 less than 10 mm Hg; good: capillary density of 20/mm 2 or more, present reactive hyperemia in CM and LD, TcpO 2 of 30 mm Hg or more). Subsequently, patients received maximum conservative therapy from the surgeon, who was unaware of the microcirculatory results. After a follow-up period of as long as 36 months, limb survival and disposing factors were analyzed and compared with the initial microcirculatory status. Results: Cox regression analysis showed a significant prognostic value of the microcirculatory classification (hazard ratio = 0.28, P < .0001), but not of the Fontaine stage, ankle blood pressure, or the presence of diabetes mellitus for the occurrence of an amputation. Positive and negative predictive values were 73% and 67%, respectively. The cumulative limb survival at 6 and 12 months was 42% and 17% in the poor microcirculatory group, 80% and 63% in the intermediate microcirculatory group, and 88% and 88% in the good microcirculatory group ( P < .0001, log-rank). Conclusion: Microcirculatory screening and classification is useful in detecting non-reconstructible critical ischemia that requires amputation, which is not detectable by means of the clinical stage or blood pressure parameters. Most of the poor patient group will require amputation. In the intermediate and good groups, nonsurgical treatment appears sufficient for limb salvage. (J Vasc Surg 1999;30:114-21.)