Teaching Case

The patient presented to the hospital with mild pain in his buttocks and both legs, especially after short walks. Peripheral pulses of both legs were weakly present. No other complaints were present, blood chemistry findings were within their normal range and the patient was a heavy smoker. The angiologist requested an inferior extremities angio computed tomography (angioCT).

In angioCT a long thrombus in a 6 cm aneurism of abdominal aorta was found, a few cm above renal arteries until left common iliac artery (Fig. 1, 2). Right kidney is fed by two normal renal arteries while the left renal artery has a small dilatation in its origin but is not obliterated (Fig. 1b). Down to the common iliac arteries the thrombus completely obliterates the right one and the left common iliac artery is completely obliterated few cm away from its origin. Four collateral feeding arteries to the both common femoral arteries come from superior and inferior mesenteric arteries under the anterior abdominal wall (Fig. 2, 3). Down on the legs there are no changes in respectively arterial trees.

Most of the patients with peripheral arterial disease (PAD) suffer from peripheral atherosclerosis. Other causes of PAD include aneurysms, fibromuscular dysplasia, thromboembolic disease, vasculitis, trauma, congenital abnormalities, and entrapment syndromes. In addition, arterial kinking, especially of the iliac artery, may result in endofibrosis and claudication. Other conditions that mimic PAD are deep venous thrombosis, musculoskeletal disorders, osteoarthritis, peripheral neuropathy, and spinal stenosis. Atherosclerotic PAD is a common entity and affects large proportions of many worldwide populations. The total disease prevalence documented in several epidemiologic studies is between 3% and 10%. Its prevalence increases to 15–20% in patients over 70 years. [1-4]
Major risk factors implicated in the development of atherosclerotic PAD are diabetes, cigarette smoking, hypertension, and hyperlipidaemia. While PAD is 1.5 times more prevalent in smokers, diabetes is one of the strongest predictors for the development of PAD. Symptoms of PAD depend on the stenosis severity, the degree of collateral circulation, and the vigor of the exercise. Patients may be asymptomatic (25–50%), experience intermittent claudication (1–2%) A lack of symptoms may be due to physical inactivity. Atypical leg pain is seen in 40–50% of PAD patients while classical claudication is experienced in 10–35%. One of the typical forms of PAD is aortoiliac occlusive disease, also known as Leriche syndrome (LS), which is atherosclerotic occlusion of the lower abdominal aorta and/or both of the iliac arteries. LS is a condition where the patient suffers from three main symptoms: 1) Claudication which refers to pain or cramps of buttock area that develop with increased walking or exercise. 2) Impotence, failure to achieve or maintain an erection in males. 3) Decreased pulses in the lower limbs. In LS the ankle-brachial index (ABI) is very useful finding. Using Doppler ultrasound at bedside, the pressure at the brachial artery and at the posterior tibialis artery are measured. The ankle systolic pressure is divided by the brachial pressure. Normally, the ratio is more than 1. In disease, it may be less than 0.5. [1, 2, 3, 8, 9, 10]
Useful imaging diagnostic examinations are colour duplex Doppler and angioCT. Angiography MR is not always available and takes a long time to be performed. Conventional angiography with digital substruction is the gold standard but it is an invasive one and it is reserved for interventional options of treatment. AngioCT with MIP, multiplanar and 3D reconstructions can decide the final diagnosis. AngioCT and color Doppler are very useful screening imaging methods after treatment as well. [4-7]