Leriche syndrome, also known as Leriche's syndrome is a type of occlusive peripheral artery disease that occurs at the bifurcation of the abdominal aorta into the common iliac arteries.
Leriche syndrome classically presents in the form of a triad of specific symptoms. The most common of these is claudication, which is described as muscle cramping pain of the lower extremities present during exertion and alleviated by cessation of activity. Characteristically, for each particular patient the time after exertion at which claudication occurs is almost always constant. Cramping is experienced firstly in the calf muscles and may progress to involve muscles of the buttocks, hips and thighs. Claudication of thigh or buttock muscles is a sign of severe aortoiliac disease. Further physical examination may reveal cold, pale and weak extremities.
The second symptom in the triad is impotence manifested as difficulty or inability to maintain penile erection. This usually accompanies buttock claudication.
The third symptom in the triad is a weak or absent femoral pulse resulting from more proximal arterial occlusions . Critical limb ischemia in the lower limbs rarely develops because of the presence of alternative blood supply sourced from a dense network of collateral blood vessels that form as the disease progresses slowly over time.
Peripheral arterial disease is diagnosed based on clinical history, physical examination findings and relevant diagnostic investigations. Symptoms are identified in the patient's history while suggestive signs are elicited objectively by the clinician. Examination of peripheral pulses alongside measurement of blood pressure is key. Pulse areas that are checked include the radial, brachial, femoral and popliteal. There is reduced or absent pulse in the arteries distal to the point of occlusion. Alongside checking for pulse, examination for patency of circulation in the extremities is also done by assessing for pallor and temperature changes on the skin over the extremities. Differences in blood pressure between one limb and the other or between a more proximal part and a distal part of the limb point towards the presence of a peripheral arterial disease.
Imaging tests are also used to achieve a diagnosis of occlusive arterial disease. The modality of choice is the non-invasive computed tomography (CT) angiography, which if not available may be substituted by magnetic resonance angiography (MRA) with contrast enhancement . Another form of imaging is Doppler ultrasonography that is ideal for diagnosis of vascular occlusion. Radiographs can also be used for assessment. Invasive angiography is best employed if there is intention to carry out any form of surgical intervention on the occluded vessels.
Laboratory blood tests are done to rule out possible differential diagnoses that may present with vascular occlusion.
The goal of treatment in Leriche syndrome is to correct the inadequate blood supply to the extremities by enhancing vascularization.
This involves procedures to either remove the occlusion or create a bypass around it. This may either be achieved through invasive surgery or by use of endovascular techniques that include aortoiliac endarterectomy, percutaneous transluminal angioplasty with or without stent placement, aortobifemoral bypass, axillary-bi-femoral and femoral-femoral bypass.
The use of drugs to alleviate muscle claudication is advised. Pentoxyfylline and cilostazol are examples of recommended drugs. Antiplatelets are also administered as prophylaxis against hypercoagulation of blood.
Treatment of underlying risk factors
Medical conditions such as hyperlipidemia, diabetes and hypertension must be well controlled because they predispose to development of peripheral arterial disease. Social habits like smoking require cessation as they impact negatively on the prognosis.
Being an aortoiliac disease, prognosis of Leriche syndrome is determined by considering patient outcomes in two ways: the rate of mortality associated with arterial surgical repair and the viability of such repairs over the course of time. The following is a table illustrating the different outcomes that determine mortality.
|Surgical procedure||Surgery related mortality within 30 days||Rate of patency over 5 years|
As an alternative to the conventional surgical procedures above, endovascular techniques are also employed in the management of aortoiliac disease. The most common interventions include placements of stents and percutaneous transluminal angioplasty (PTA). These two procedures are considered ideal for the management of isolated stenosis of the infrarenal aorta or common iliac arteries.
Impressive outcomes have been recorded when PTA is used to correct localized, segmental occlusion of the aorta with a success rate in 95% of the population and a 5 year rate of patency of 80-87%. Likewise, in iliac artery occlusive disease the success rate is 93-97% of the population and a 5 year patency rate of 54-85%. For both aortic and iliac stenosis, better outcomes have been recorded when intrarterial stents are used in isolation or in combination with PTA.
Comparison of the efficacy of endovascular techniques and open bypass surgical interventions for the treatment of aortoiliac disease reveal unique differences in clinical outcomes. Open bypass surgical interventions were linked to higher patency rates initially and over the course of 5 years. On the other hand, endovascular techniques were associated with lower 30 day mortality rates as well as lower rates of complication and reduced length of hospital stay .
Leriche syndrome arises most frequently due to obstruction at the aortoiliac bifurcation by atherosclerotic plaques and thrombi. Vasculitis may also play a causative role . Once obstruction sets in, several collateral pathways are formed to bypass it and allow vascular flow to the lower limbs . These include:
Owing to the fact that half of the patient population diagnosed with peripheral arterial disease are symptom-less, little is known concerning the incidence and prevalence of Leriche syndrome. However, documented data shows that the syndrome occurs more commonly in patients with peripheral arterial disease especially with advancing age. Thus, a quarter of the US population at the age of 70 experience the disease.
The presence of atherosclerotic plaques and thrombi in the infrarenal aorta, common iliac, internal and external iliac arteries leads to the development of Leriche syndrome  . The syndrome then slowly progresses to involve both the proximal and distal portions . Atherosclerosis in itself develops in a very intricate way and there is yet to be found a specific etiological basis for it. There are however a number of factors that have been associated with the development of atherosclerotic lesions.
The baseline that initiates the disease process in Leriche syndrome is injury to the arterial wall. The most common triggers are the following:
An arterial wall injury immediately triggers an inflammatory response with gravitation of macrophages to the site of the injury. Lipid accumulation onto these macrophages ensues with deposits of cholesterol, cholesterol esters and triglycerides collectively forming an atheroma. Any exposure of the atheroma contents to platelets circulating in blood triggers platelet aggregation. Glycogen receptors on the surface of platelets are activated causing them to bind to fibrin thus forming a new blood clot. The atheroma-clot complex forms a plaque on the arterial wall causing obstruction. Unstable plaques may break away forming atheromatous emboli that may eventually cause occlusion of the arterial lumen in distal vessels. Significant occlusion occurs when an atheroma increases in size to the extent that it covers at least 50% of the intraluminal arterial space. With such a stenosis, the velocity of blood flowing through the artery is bound to increase.
In the absence of exertion, oxygen requirements of the lower limbs are low and can be catered for even in the presence of a more proximal arterial stenosis. On the contrary, during exertion an oxygen debt is created within the skeletal muscles and this cannot be readily reversed due to obstructed blood flow caused by the stenosis. The effects of this obstruction range from mild symptoms of claudication to features of critical limb ischemia. The latter, however, is rarely associated with aortoiliac disease only, but is more common when arterial occlusion occurs in multiple arterial segments. At its worst, it may cause loss of limb tissue.
Leriche syndrome has varied presentations depending on the underlying pattern of atherosclerosis. The first pattern (type I atherosclerosis) affects only the infrarenal and common iliac arteries. It is more prevalent in women and is found in 5-10 % of the population with peripheral arterial disease. The second pattern (type II atherosclerosis) typically affects the infrarenal aorta, the common iliac and external iliac arteries but may progress to also include the common femoral arteries. The third pattern (type III atherosclerosis) is considered the most critical and most prevalent, found in 35% of patients with peripheral arterial disease. It shows involvement of the infrarenal aorta, iliac artery, femoral artery, popliteal artery and tibial artery.
Prevention of Leriche syndrome lies in identifying and eliminating known or modifiable risk factors. Measures to be undertaken include:
The first time Leriche syndrome was ever described was in 1814 by Robert Graham . However, it was the French surgeon Rene Leriche who was able to connect the disease process and its impact on physiology with the abnormal anatomy identified in Leriche syndrome. Henceforth the condition was described as a triad of symptoms: erectile dysfunction, claudication of the lower limbs and decreased or absent femoral pulses. Leriche later became the first person to publish on the subject after treating a 30 year old patient and successfully resolving his erectile dysfunction and pain associated with walking .
Leriche syndrome has a very significant occurrence in patients with peripheral arterial disease. In the latter condition, atherosclerosis leads to the formation of plaques in the infrarenal aorta, common iliac, internal and external iliac arteries. The pattern involves either one of the arteries or several of them concurrently. Depending on their size, plaques may cause arterial lumen obstruction with subsequent impairment of blood flow to the extremities. Other symptomatology occurs due to formation of thrombi and emboli from plaque disintegration. Obstruction in the more proximal vessels is easily recognized when palpation of the femoral artery reveals decreased or absent pulse.
Typically, Leriche syndrome is associated with a poorer prognosis as compared to more distal peripheral arterial diseases . It is important then to have early recognition of the risk factors implicated in peripheral arterial disease for prompt initiation of non operative treatment. This measure will ensure general improvement of the patient's well-being.
Leriche syndrome is a disease that results from occlusion of peripheral arteries specifically at the point where the major blood vessel (aorta) divides to form its terminal branches, the common iliac arteries. This occlusion arises due to an obstruction of the artery by a plaque, a substance consisting of fats and clotted blood.
The symptoms and signs of this disease arise due to the reduced flow of blood into the regions beyond the occlusion (from the buttocks downwards to the legs). These features are typically:
A diagnosis is usually made when these features are present and after further clinical examination reveals deranged blood pressure and impaired circulation to the extremities as evidenced by cold, pale and weak limbs. Imaging tests are also used to confirm the diagnosis.
Leriche syndrome presents more commonly in males in the age bracket of 60 to 70 years. A number of factors predispose to the development of this condition. These include underlying high blood pressure, diabetes mellitus, high levels of blood cholesterol and smoking. Stopping these disorders from developing or progressing is important in the prevention of Leriche syndrome. It also demands for lifestyle modifications by engaging in regular exercise, maintaining a healthy weight and cessation of smoking.
For treatment of Leriche syndrome, certain medications (antiplatelets) are administered to prevent abnormal blood clot formation that would pose danger to the circulatory system. Drugs that help relieve muscle cramping (e.g. pentoxyfylline and cilostazol) are aslo prescribed. However, the mainstay of treatment in Leriche syndrome is surgery whereby the diseased part of the artery undergoes reconstruction or a bypass is created around it. Most of the surgical interventions are successful.