Pattern and distribution of peripheral arterial disease in diabetic patients with critical limb ischemia (rutherford clinical category 4-6)

Abstract

Background: This study investigated the pattern and distribution of peripheral arterial disease in diabetic patients with critical limb ischaemia (CLI) and to stratify the findings according to the patients’ risk factor profile, gender and age group.
Methods: We conducted a one-year prospective descriptive study (January 2014 to December 2014) at Groote Schuur Hospital, University of Cape Town. The research protocol and the informed consent were approved by the Institutional Review Board, and all subjects included in this study gave an informed consent. We included all diabetic patients over the age of 18 years with critical limb ischemia who had pre and post-intervention vascular imaging. The calculated minimum sample size was 63 limbs. We hypothesize that the proportions of arterial segment patency categories and the arterial foot arch status varies according to gender, age group and risk factor combinations in diabetic patients. The Null hypothesis (N0) assumes that the proportions of arterial segment patency categories and arch status are the same in diabetic patients irrespective of gender, age group and risk factor combination. The equality of distribution was analysed using the One Sample Chi-square test. Three risk factor combination groups were analysed: Group 1 (diabetes mellitus, hypertension, dyslipidemia), Group 2 (diabetes mellitus, hypertension, dyslipidemia, ex-smoker) and Group 3 (diabetes mellitus, hypertension, dyslipidemia, smoker).
Results: Seventy-one patients were analysed (38 females and 33 males). We recorded the patency grades (ranging from normal to occlusion) of arteries in all 3 lower extremity arterial segments (aortoiliac; femoropopliteal and tibioperoneal segments). Altogether the patency grades of 820 lower extremity arteries were recorded. Diabetics, collectively, were found to have more severe occlusive disease in the tibioperoneal segment (P < .001). Group 3 patients however, had more severe occlusive disease in the femoropopliteal segment compared to the other subgroups (P < .001). Group 1 and Group 2 patients had more severe occlusive disease in the tibioperoneal segment (P < .001). Females were more likely to have complete foot arches (22/37; P = .004) while males tended to have more incomplete foot arches (17/32; P = .048).
Conclusion: Diabetic patients collectively have severe tibioperoneal occlusive disease. However, Group 3 patients tend to have disproportionately more occlusive disease in the femoropopliteal segment (P < .001). Diabetic female patients with CLI are more likely to have a complete arterial foot arch than males (P = .004).