Definition & Overview
Pulmonary artery embolectomy is a medical procedure that removes an embolus from the inside of the pulmonary artery. An embolus (plural, emboli) refers to any particle inside the arteries or veins. Clinical examinations show that most emboli, if not all, are composed of clotted blood cells.
Some emboli may not cause serious harm and even symptoms. In fact, some can dissolve on their own. However, if they accumulate over time, they can pose a serious health threat because they can potentially obstruct the blood vessel cavity. Blocked blood vessels can eventually rupture, which can lead to internal bleeding.
The pulmonary artery is one of the only two arteries (the other is the umbilical artery) in the body that carries deoxygenated blood from the heart to the lungs.
In some cases, the presence of an embolus in the pulmonary artery can be a major health issue and can cause high mortality rate despite of the many advancements in embolectomy. The reason being is that emboli can break away and rupture at one point during the operation and travel to other blood vessels. When this happens, there is a possibility that they will get trapped in one area, creating a major blockage in the process. Often, this blockage happens in the brain and can cause serious health hazards and sometimes, even death.
In some cases, a procedure called thrombolysis (a process of dissolving blood clot with a drug that acts like an enzyme), can be useful. However, the downside is that many patients who were administered with such drug often experience internal bleeding.
For patients with anatomically extensive pulmonary embolism, or large deposits of emboli in the pulmonary artery, they almost always experience haemorrhage within the skull (intracranial haemorrhage) when administered with a thrombolytic drug. For this reason, surgical methods are often considered for the treatment of the condition.
Pulmonary artery embolectomy can be performed with or without cardiopulmonary bypass, a medical technique where the function of the heart and lungs is temporarily taken over by a machine, called CPB pump, because the organs are unable to perform their normal function during the operation.
Surgeons decide whether to use or not to use cardiopulmonary bypass following a thorough assessment of the patient's condition and unique circumstances. Although the procedure can, in many cases, improve the chances of a successful operation, it can also lead to postsurgical complications.
Who Should Undergo and Expected Results?
Pulmonary artery embolectomy with or without cardiopulmonary bypass is often indicated for patients suffering from aggressive pulmonary embolism. These patients typically present with symptoms that are very similar to other conditions including pneumonia, heart attack, and asthma. For this reason, there have been cases where patients were misdiagnosed. These symptoms include:
- Sudden, sharp chest pain
- Sudden shortness of breath
- Rapid heart rate
- Coughing up foamy mucus or blood
Based on statistics, up to 89% of pulmonary artery embolectomy patients survive the procedure. However, some patients suffer from serious complications, including death, as early as a month after surgery. Despite that, pulmonary artery embolectomy is still used to extend the life of patients nearing death due to their dysfunctional haemodynamic profile.
Haemodynamics refers to the flow of blood to the organs and tissues of the body.
How is the Procedure Performed?
Pulmonary artery embolectomy is performed through a procedure called median sternotomy, which is performed by making a vertical incision along the sternum (breastbone). Doing so separates or divides the breastbone and allows surgeons to access the heart. The procedure requires general anaesthesia.
A transverse arteriotomy (cutting or opening the arterial wall) is then performed to remove emboli around the pulmonary artery. The identified clots can be removed all at the same time using simple gallbladder stone forceps. In some cases, venous drainage using a vacuum is also used.
To prevent recurrences, filters are put in place in the inferior vena cava immediately after the operation before the breastbone is sutured and closed.
Patients are placed under intensive care for a day or two right after the procedure for close monitoring. Any breathlessness, nagging or intolerable pain in the chest, and discharge at the incision area should be reported to the surgeon immediately.
Possible Risks and Complications
Postoperative clinical data shows that some patients developed hypotension (abnormally low blood pressure) and hypoxemia (abnormally low concentration of oxygen in the blood) during and after surgery. Some also develop tamponade (abnormal pressure around the heart) due to the accumulation of excess fluid in and around the pericardial cavity. The development of tamponade is very common with patients suffering from cancer or those who have gone through minimally to highly invasive surgical procedures on the heart and lungs. Infections can also happen and are treated with antibiotics.
Patients also face the risks associated with any type of open surgery including adverse allergic reactions to anaesthesia and blood loss.
Other risks include arrhythmias, cholesterol embolism, ruptured blood vessels, and damage to surrounding organs and tissues.
US National Library of Medicine National Institutes of Health; “Aggressive Approach to Pulmonary Embolectomy for Massive Acute Pulmonary Embolism: A Historical and Contemporary Perspective”; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931612/
Ahajournals; “Acute Pulmonary Embolectomy: A Contemporary Approach”; http://circ.ahajournals.org/content/105/12/1416