Comparison of colour Doppler ultrasound and ankle-brachial pressure index measurements in peripheral vascular disease in type 2 diabetic patients with foot infection

Abstract

Background: Peripheral vascular disease is diagnosed by definitive history of intermittent claudication or if one or more of peripheral pulses are absent in one or both lower limbs. Diagnostic testing for peripheral vascular disease must be accurate, inexpensive, widely accessible, easy to perform and preferably non-invasive. A variety of non-invasive techniques are available to detect the presence of peripheral vascular disease as well as to localize areas of stenosis, assess severity of disease and follow patients for disease progression or response to therapy. In this study we compare the specificity and sensitivity of ankle brachial pressure index with colour Doppler ultrasound for diagnosis of peripheral vascular disease in type 2 diabetes. Methods: This prospective study was carried out in the department of General surgery, GMCH, Udaipur, Rajasthan, India, from September 2014 to February 2016 after taking the permission from institutional ethical committee. A total of 50 patients were selected. The selected patients were evaluated by detailed clinical history, physical examination, local examination, ankle brachial pressure index (ABPI), colour doppler study and other relevant investigations. The ABPI ratio was calculated in every patient and an ABPI less than 0.9 in either foot was defined to have PVD. Colour duplex ultrasound was done in all selected patients. Imaging of peripheral arteries of the lower limbs was done using high resolution colour duplex ultrasound. PVD was diagnosed if the stenosis in the artery was greater than 50% or presence of occlusion. Results: Total 50 patients having type 2 diabetes mellitus with foot infection were included and most of the patients were between 40-60 years of age (68%) with males preponderance. In our study 12 (24%) patients had normal ABPI of 1.0 to 1.29 and 22 (44%) patients were in the range of mild to moderate PVD with ABPI between 0.41 to 0.90. Colour doppler was used as a standard diagnostic test for PVD & out of 50 patients, 36 (72%) showed involvement of arteries and among them both anterior and posterior tibial arteries were involved in 12 (24%) patients. In our study colour doppler ultrasound was used as standard diagnostic method for PVD. The sensitivity, specificity, positive predictive value and negative predictive value of ABPI against colour duplex ultrasound were calculated. Conclusions: In our study it’s concluded that ABPI is a good initial screening tool for peripheral vascular disease, but some patients with significant stenosis or in whom collaterals have developed in lower extremity would be missed, if ABPI measurement alone is used for diagnosis of peripheral vascular disease.