Inflammatory aneurysm, also known as mycotic aneurysm, is a local widening or bulging of the lumen of an artery as a result of an inflammatory process in its wall. Despite the fact that it is a relatively rare disease, it can cause serious complications.

Inflammatory aneurysm( mycotic aneurysm ) was first described in 1885 by the Canadian physician William Osler, who called it " mycotic ". Currently, this description may be misleading and suggest a fungal etiology (today we know that only a few are caused by fungi). In fact, it was referring to the "mushroom" shape of the aneurysm. They are rare and account for only 1-3% of all aneurysms.

How is an inflammatory aneurysm formed?

Inflammatory aneurysms can arise in several ways. As a result of bacteremia (the presence of bacteria in the bloodstream) resulting from the generalization of the inflammatory process, the bacteria penetrate into the small vessels that feed large arteries. There, local infiltration of inflammatory cells occurs, which leads to the gradual destruction of the artery wall, its weakening and, ultimately, abnormal dilatation.

Another reason may be the so-called septic embolism. In this situation, the microbes spread with the bloodstream in the form of a dense conglomerate composed of, among others, platelets and fibrin from a specific focus. A classic example is the embolism caused by a fragment of bacterial vegetation that forms on the heart valves in the course of infective endocarditis (IE). A mycotic aneurysm may develop at the site of blockage of the artery with this type of embolic material. Before the era of antibiotics, IE was the most common cause of inflammatory aneurysms.

Inflammation within the arterial wall may also be caused by the spread of infection through continuity from the surrounding areas. Inflammatory aneurysms may also be caused by a not fully understood immune process. Inflammatory aneurysms must be distinguished from infection within the vessel wall that occurs in previously dilated arteries - the so-called infected aneurysms.

The most common pathogens responsible for the disease process today areSalmonella ,StaphylococcusandStreptococcus.

In the past, an important etiological factor of such changes wasTreponema Pallidum , i.e. the pale spirochete responsible for syphilis. One of the manifestations of cardiovascular syphilis developing in the course of many years of infection was syphilitic aortitis and, consequently, aneurysms. Today they are rare.

Where are inflammatory aneurysms located?

Most often they are located in the area of ​​large and medium-sized vessels - the abdominal and thoracic aorta, intracranial arteries and femoral arteries. Less frequently in peripheral and visceral arteries.

What are the risk factors?

Risk factors may be clinical situations leading to the weakening of the structure of arterial walls, such as:

  • atherosclerosis
  • hypertension
  • smoking
  • collagenosis
  • iatrogenic damage
  • older age

and also those that favor the spread of infection and the formation of its foci:

  • diabetes
  • immunosuppressive treatment
  • HIV infection
  • intravenous medication (or drug).

What symptoms can an inflammatory aneurysm have?

Unbroken inflammatory aneurysms usually do not present specific symptoms. General symptoms such as:

  • weakness
  • fever
  • weight loss

Deviations in laboratory tests may be an increase in ESR and CRP, but these changes only indicate an undefined inflammatory process in the body. Other symptoms may be due to the specific location and the widening of the vessel circumference. For example, aneurysms within the abdominal aorta can cause non-specific pain in the abdomen or lumbar region, and may even manifest as problems with urine outflow. Localization in the thoracic region may result in pain in the chest, interscapular region and symptoms of aortic regurgitation. In turn, cerebral aneurysms carry a risk of neurological deficits and intracranial bleeding. Large peripheral aneurysms can be felt relatively easily through the skin as a pulsating tumor.

Mycotic aneurysm: diagnosis

The little characteristic symptom, however, means that imaging tests are necessary for the final diagnosis and then implementation of the appropriate treatment. Here, the best computed tomography with contrast allows to visualize the vessels - the so-called angioKT. In the next projection, magnetic resonance imaging (MRI) tomography is also used. For the initial examination in patientsaneurysms, including ultrasound may be used in the abdominal aorta and peripheral arteries.

In the case of this aneurysm, it is also very important to locate the possible root cause, e.g. bacterial vegetation in the heart or other inflammatory focus. Each patient requires blood cultures and echocardiography.

Inflammatory aneurysm: treatment

Treatment of inflammatory aneurysms basically consists of two simultaneous procedures: antibiotic therapy to eliminate pathogens and surgical treatment.

Broad-spectrum antibiotics should be started before the causative agent is identified (empiric antibiotic therapy). When this occurs, treatment should target the specific microorganism according to its sensitivity to the drug. There are no detailed recommendations, but the treatment should undoubtedly last several weeks.

The key element, however, is the surgical removal of the aneurysm altered vessel. Today, surgery offers a wide range of treatments. The selection of the method largely depends on the location and size of the aneurysm as well as the patient's clinical condition and the risk of complications. To put it simply, the main assumption of aneurysm treatment is to remove the pathologically changed part of the vessel and restore its continuity. For this purpose, it is used, inter alia, vascular prostheses made of plastic (additionally impregnated with silver s alts or antibiotics to reduce the risk of infection), transplantation of own or donor vessels.

Endovascular repair procedures are also used more and more often. Currently, they are mainly used in the treatment of non-inflammatory aortic aneurysms. Their main advantage over open procedures is that they are much less invasive. The disadvantage - less durability. In the context of mycotic aneurysms, they can be used, inter alia, in life-threatening conditions in patients with aortic aneurysm. Percutaneous insertion of the so-called Stent graft may be a temporary procedure prior to final surgery, which usually occurs after clinical stabilization. Endovascular methods are also used to treat intracranial aneurysms. Despite the increasing effectiveness of surgical methods, complications should not be forgotten. In the case of an inflammatory aneurysm, there may be infections in the area of ​​the prosthesis or graft, which often lead to leakage of the anastomosis.

Inflammatory aneurysm: complications

A rare inflammatory aneurysm can lead to fatal complications if not diagnosed and properly treated. Brokenaneurysms (especially of the aorta) lead to massive, life-threatening hemorrhage. A damaged aortic wall structure carries the risk of dissection. Moreover, aneurysms can be a potential source of further septic embolisms.

Inflammatory aneurysm: prognosis

Unfortunately, untreated inflammatory aneurysms are associated with high mortality. In some cases, they tend to progress quickly. These include, in particular, aortic aneurysms, i.e. vessels of the highest caliber, and intracranial aneurysms. These can cause violent, most dangerous complications.

It is very important to pay special attention to people at high risk of developing an inflammatory aneurysm. Efficient implementation of causal treatment may prevent this dangerous complication of a spreading infection.

Category:

Cardiology