Angioplasty, bypass surgery, and amputation for lower extremity peripheral arterial disease in Maryland: a closer look.

Tunis and colleagues attempted to assess the effect of peripheral angioplasty in a large population with descriptive epidemiologic methods. Their study suffered from a vague statement of purpose, inappropriate and inadequate outcome measures, undetermined differences in prevalence of peripheral vascular disease and prevalence of risk factors for bypass/amputation in 1989 versus 1979, no differentiation between levels of amputation or between primary and secondary amputation, lack of a unique ICD-9-CM code indicating angioplasty for peripheral vascular disease of the lower extremities, lack of unique patient identifiers, a mistaken perception of the adoption of angioplasty as "widespread" in Maryland, and the assumption of uniform coding accuracy throughout the period of study. We conclude that the study design of Tunis et al was inadequate to determine the beneficial effects of angioplasty or bypass surgery in the treatment of peripheral vascular disease. Moreover, the conclusion by Coffman (2) that "invasive procedures are indicated only for the severely ischemic limb" is completely unsupported by the study data. Physicians should not attempt to apply the results of the study by Tunis et al to individual case situations. It should be further appreciated that the study findings do not provide an adequate basis for policy-making decisions. It is clear that important clinical questions concerning the roles of angioplasty, bypass, and amputation should be answered with more definitive studies.