Evaluation of a Paraclinical Test for the Diagnosis of Arterial Insufficiency in Diabetic Patients With Foot Ulcers : INFLUX-D Study

The number of people living with diabetes has quadrupled worldwide since 1990, and more than 4.5 million people in France have diabetes. This chronic disease is a major cause of blindness, kidney failure, myocardial infarction, stroke, and lower-limb amputation. In France, in 2013, the incidence rates of hospitalizations for lower-limb amputation and diabetic foot ulcer among people with diabetes were 252 per 100,000 and 668 per 100,000 individuals with diabetes, respectively.

The management of diabetic foot disease requires a multidisciplinary approach involving general practitioners, diabetologists, dietitians, podiatrists, physiotherapists, and nurses. Nurses working in diabetic foot clinics, wound care centers, and community settings play a key role throughout the continuum of care for people with diabetes. Their responsibilities include prevention, patient education, clinical monitoring, and wound management. When one or more warning signs are identified, nurses promptly alert the physician to ensure early management of infection and timely referral to the appropriate healthcare professional(s).

One of the major factors contributing to impaired wound healing and ultimately leading to amputation in people with diabetes is arterial insufficiency. This condition is most commonly caused by peripheral artery disease (PAD), which is characterized by progressive atherosclerotic obstruction of the arteries supplying the lower limbs and represents a major cardiovascular disease. In patients with diabetes, PAD differs from atherosclerotic disease in non-diabetic individuals not only because of its higher prevalence but also because of its earlier onset, its frequently asymptomatic course, its predominantly distal distribution involving the infrapopliteal and even below-the-ankle arteries, and its greater severity.

The reference standard for diagnosing arterial insufficiency in patients with diabetes relies on quantitative microcirculatory assessment performed by vascular specialists. These investigations are based on arterial Doppler ultrasound and combine ankle and toe pressure measurements. The ankle-brachial index (ABI), the standard diagnostic test for PAD in non-diabetic patients, has limited reliability in individuals with diabetes because medial arterial calcification frequently renders the arteries incompressible. In contrast, toe pressure measurements can be performed in virtually all patients with diabetes who have intact toes. In selected cases, transcutaneous oxygen pressure (TcPO₂) measurement may also provide valuable additional information.

The availability of these investigations depends on access to vascular specialists, as a comprehensive vascular assessment may take up to two hours and varies according to local clinical practice and available resources.

Portable handheld vascular Doppler devices equipped with an 8-MHz probe are now available at an affordable cost and can be readily used in diabetic foot clinics, wound care centers, and community-based practices.

We hypothesize that this medical device, which assesses the overall hemodynamic status of the lower limb, could serve as a first-line screening tool for patients with diabetes presenting with a foot wound. This rapid assessment could facilitate early identification of patients requiring further vascular investigations by a vascular specialist when no arterial blood flow is detected.