What does it consist of?
Thromboangitis obliterans (OAT), an inflammatory vasculopathy also known as Buerger’s disease, is characterized by an inflammatory endarteritis that causes a prothrombotic state and subsequent vaso-occlusive phenomena.
The inflammatory process typically affects the small and medium arteries, as well as the veins of the upper and lower extremities. The condition is strongly associated with the intensive use of tobacco, and the progression of the disease is closely related to continued use.
Patients usually present moderate to severe claudication that can progress rapidly to critical ischemia of the limb with pain at rest or loss of tissue.
The characteristics of acute ischemia of the extremities (eg, pain, paresthesia, pallor, mottling, poikilothermia, paresis and lack of pulse) are common signs and symptoms found in emergency situations.
Pharmacological therapy is generally ineffective; Tobacco abstinence is the only known measure to prevent the progression of the disease.
Given the arteritis of small and medium vessels, surgical or endovascular revascularization may not be possible, due to the absence of a distal target for revascularization.
As the disease progresses, amputation may be the only viable option.
Pathophysiology and Etiology
As noted, the development of OAT is strongly associated with the intensive use of tobacco, and the progression of the disease is closely linked to continued use.
Some observations suggest the existence of an immunological phenomenon that leads to a vasodisfunction and inflammatory thrombi. Patients with OAT have hypersensitivity to tobacco extracts injected intradermally, increased cellular sensitivity to collagen types I and III, high titers of anti-endothelial antibodies in serum and alteration of peripheral endothelium-dependent vasorelaxation.
They also show a higher prevalence of human leukocyte antigen (HLA) -A9, HLA-A54 and HLA-B5, suggesting a genetic component of the disease.
Causes of Buerger’s disease
The cause of Buerger’s disease is not always known. Some patients with this condition may be genetically predisposed to develop it.
Buerger’s disease begins by causing the arteries to swell and blood clots to form in the blood vessels. This restricts normal blood flow and prevents blood from circulating completely through your tissues.
This results in tissue death because the tissues do not have enough nutrients and oxygen.
The risk of developing Buerger’s disease increases when you smoke heavily. Scientists do not know why tobacco smoke increases this risk, but the correlation between the two is well documented.
- United States statistics.
The prevalence of OAT has declined in the last decade, partly because the prevalence of smoking has declined, but also because the diagnostic criteria have become stricter. In 1947, the prevalence of the disease in the United States was 104 cases per 100,000 inhabitants.
Since then, the prevalence has been reduced to an estimated 12.6-20 cases per 100,000 inhabitants.
- Demography by age, sex and race.
The majority of patients with OAT are between 20 and 45 years old; The disease does not occur in pediatric or elderly patients. TAO is more common in men (ratio of males to females, 3: 1); However, it is believed that the incidence in women is increasing, probably as a consequence of the increasing frequency of smoking among women.
The disease is relatively less common in people of northern European descent; Natives of India, Korea and Japan, along with Israeli Jews of Ashkenazi descent, have the highest incidence of OAT.
Recognizing the symptoms of Buerger’s disease
Buerger’s disease usually begins with pain in the affected areas, followed by weakness in the same areas. Symptoms include:
- Pain in the hands and feet or legs and arms, which can come and go.
- Open sores on the toes.
- Swollen veins
- Pale fingers when it is in cold temperatures.
Tests and diagnosis
There is no test to determine if you have Buerger’s disease. However, there are tests that your doctor can perform to rule out other conditions.
A simple blood test can help your doctor determine whether your symptoms are lupus, diabetes, or blood-clotting disorders, which can have the same symptoms as Buerger’s disease.
In some cases, an angiogram may be necessary, which checks the health of your arteries. In this test, your doctor injects a dye into your artery and then performs an x-ray of the area to see blockages in your arteries.
Another test that your doctor can perform is called an Allen test. This is a non-invasive test that requires you to make a clenched fist while your doctor presses on the artery of your hand.
When you open your fist and your doctor releases the pressure from the artery, your hand should quickly go from pale to its original color. If the color changes slowly, this could be a sign of Buerger’s disease.
Death due to TAO is rare. Between 1999 and 2007, according to data from the Centers for Disease Control and Prevention in the United States, the OAT was the underlying cause of 117 deaths in the United States.
A surprising dichotomy is observed in the prognosis of patients with OAT, which depends on whether absolute avoidance of tobacco is achieved.
Among patients who quit smoking, 94% avoid amputation; Among patients who stop using tobacco before progression to critical limb ischemia, the amputation rate is close to 0%.
In sharp contrast, among patients who continue to use tobacco, there is an amputation rate of 43% in 8 years.
Patients with OAT should be advised repeatedly to cease all use or exposure to tobacco products (including chewing tobacco, nicotine patches and gums, and second-hand tobacco smoke) and be assured that if are able to discontinue the use of tobacco, amputation will be avoided.
Physicians should advise patients that the level of avoidance of tobacco necessary to achieve the resolution of their disease often requires that their exposure be strictly limited even to smoke by being passive smokers.
This can be extremely difficult for patients who live with another smoker and, therefore, it is not unreasonable to consider referring these patients (and their loved ones) to multidisciplinary smoking cessation programs.