Role of arterial duplex of both lower limbs in the evaluation of diabetic foot

Introduction
Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia and dyslipidemia. Abnormalities in nutrient metabolism and vascularity resulting from DM lead to lower limb arterial diseases and ischemia, and this leads to infection, foot ulcers, and impairment of wound healing. Color Doppler ultrasound is a widely available noninvasive technique in the assessment of arterial affection of lower limbs that occur with DM. Color Doppler ultrasound has lots of advantages over other diagnostic imaging modalities; it is a feasible modality available in nearly all hospitals, being cheap, accurate, and safe.


Aim
The aim was to highlight the role of arterial duplex to better delineate vascular anatomy, localize the obstruction, assess the severity of stenosis, and detect the presence of collaterals, and distal runoff in patients with diabetic foot disease.


Materials and methods
Ultrasound color and Doppler examinations were performed to 20 patients previously diagnosed to have DM; the arterial supply of lower extremities was divided into these segments: common iliac artery, external iliac artery, common femoral artery, superficial femoral artery, profunda femoris artery, popliteal artery, anterior tibial artery, posterior tibial artery, peroneal artery, and dorsalis pedis. Arterial lesions were located by changes in vessel caliber, changes in color flow patterns, and broadening of Doppler waveform, quantified by measuring the peak systolic velocity (PSV) ratio across a lesion and by comparing the PSV within stenosis with that proximal to the lesion; this ratio was independent of individual variations in blood pressure, vascular compliance, and cardiac function.


Results
In all, there were 20 patients (400 segments), 35 segments showed significant stenosis (luminal narrowing ≥50% of artery diameter and PSV ratio ≥2), 21 segments were occluded, eight of them were with no distal collateral refilling, and 100 segments showed nonsignificant stenosis (luminal narrowing <50% of artery diameter and PSV ratio <2). Of 400 examined arterial segments, 297 arterial segments showed normal triphasic flow, 95 segments showed monophasic flow, eight segments had no flow indicating there was no distal refill in these segments. Of 400 arterial segments, 104 segments had low PSV (which were measured at the distal part of each segment).


Conclusion
Duplex ultrasound is an accurate easily acquired noninvasive diagnostic modality in diabetic foot patients. There was very high incidence of atherosclerosis in diabetic foot patients with more affection in below-knee arteries.