Capillary Microscopy Is a Diagnostic Aid in Patients with Acral Ischemia

Abstract

The diagnosis of peripheral ischemic diseases is a challenge to the vascular specialist, since discrimination of the different entities on clinical grounds is not always clear. Capillary microscopy is a noninvasive diagnostic technique that can visualize in particular the morphology and perfusion of the digital capillaries. The authors investigated all 522 patients who were referred to the vascular laboratory over a six-year period, in an attempt to obtain more certainty about the diagnosis of their acral ischemic complaints. Patients with clinically manifest Raynaud's phenomenon and control subjects were compared to obtain differentiation criteria. Thus, capillary microscopy scored a sensitivity of 67%, a specificity of 84%, and an accuracy of 81% to detect Raynaud's phenomenon. A disturbed capillary morphology was virtually pathognomonic in Raynaud's disease secondary to systemic disorders (specificity 100%); the accuracy was but 74%. In 69% of the patients with clinically atypical acral ischemia, capillary microscopy yielded a diagnosis. Digital blood pressure measurements, however, appeared of no use in the diagnosis of Raynaud's phenomenon. Hence, capillary microscopy appears to be a useful aid in the diagnosis of acral ischemic syndromes.