Definition & Overview
A pulmonary embolectomy is a surgical procedure used to remove emboli in the pulmonary arteries. An embolus is a mass that detaches from the body, potentially clogging an artery if it travels through the bloodstream.
A pulmonary embolectomy is usually performed in an emergency setting to avoid necrosis, a serious complication that may occur if blood flow is significantly or permanently obstructed by an embolus. As a high-risk procedure, it is performed only when other treatment alternatives, such as thrombolysis and anticoagulation, have failed.
Some experts criticise the procedure claiming that it is unnecessary in many cases. For this reason, it was almost abolished, which resulted in some cardiothoracic surgeons not receiving training for the procedure. Now, however, a pulmonary embolectomy is still considered as an important tool primarily for the treatment of advanced pulmonary embolisms but is only usually performed in combination with anticoagulation therapy.
Who Should Undergo and Expected Results
A pulmonary embolectomy can be recommended to patients who suffer from advanced cases of pulmonary embolism (massive or submassive). This is a serious and life-threatening medical condition caused by a blockage in one of the blood vessels in the lungs. In most cases, the condition causes various symptoms including chest pain and breathlessness.
In non-severe cases, embolisms are treated with anticoagulation therapy using heparin followed by warfarin.
However, some patients do not suffer from any symptoms, making the condition hard to detect, until it escalates into a massive case characterised by the following symptoms:
- Profound dyspnea at rest
- Sudden collapse
- Arterial hypotension
- Cardiogenic shock
Massive embolisms are life-threatening. Most cases of the condition are linked with deep vein thrombosis (DVT), which is a blood clot that develops in the leg. When the clot detaches from its position and travels through the bloodstream, it can get lodged in the pulmonary arteries and cause an obstruction.
Other causes of pulmonary embolism include:
- Fatty materials from the marrow of a broken bone
- Drug misuse, or the presence of a foreign material from an impure injection
- A small detached piece of a tumour
Meanwhile, the following are considered as risk factors for DVT and PE:
- Recent surgery
- Recent trauma
- Congestive heart failure
- Chronic lung disease
- Prior DVT
In patients without a history of the above risk factors, diagnosis is more challenging, as some of the early symptoms of a massive PE are similar to those caused by hyperventilation syndrome. This may lead to a misdiagnosis, causing doctors to mistakenly discharge patients. A thorough physical examination is therefore helpful, as massive PE also cause physical signs such as:
- Distended veins in the neck
- Tricuspid regurgitation murmur
- Accentuated P2
- Parasternal heave
- Sinus tachycardia, often detected in an ECG
Other possible but very rare causes include:
- Large air bubble that forms in a vein
- Amniotic fluid due to pregnancy or childbirth
The results of a pulmonary embolectomy may vary depending on the size and location of the embolus, but is also heavily influenced by how early the PE was diagnosed, the surgical technique used, and post-operative care.
Recent studies show that the mortality rate following the said procedure is now at around 20%. Although still relatively high, it is considered to have drastically improved from its previous rate of 30%. Thus, the procedure is still being performed due to its life-saving potential.
How is the Procedure Performed?
There are now a number of different techniques used to perform pulmonary embolectomy. These include:
- Surgical embolectomy - This is a major open surgery wherein the clot is removed by making an incision in an artery and blood vessel
- Balloon embolectomy - This is performed by inserting a catheter with an inflatable balloon into an artery. Once the catheter passes the clot, the balloon is inflated, and the clot is removed as the catheter is withdrawn. The catheter used in this procedure is called a Fogarty as it was invented by Thomas J. Fogarty. So far, the procedure has a recovery rate of 87.5%.
- Aspiration embolectomy - This is performed by suctioning the thrombus or embolus out. The procedure has a survival rate of 72%, but the chance of successful treatment is higher if the patient undergoes the procedure within 48 hours from the first onset of symptoms.
Possible Risks and Complications
A pulmonary embolectomy is a high-risk procedure linked with a number of potential complications. A balloon embolectomy, although minimally invasive, places patients at risk of:
- Intimal lesions, which can cause another thrombolus to form
- Ruptured blood vessel
- Cholesterol embolism
- Pericardial tamponade
- Pulmonary hemorrhage
- Blood loss
- Anaphylactic reaction
Death during or after an embolectomy is associated with delays in diagnosis and surgery.
Despite being considered as a high-risk procedure, its outcomes have significantly improved over the last 20 years, and overall mortality rating has reduced from 30% to 19%.
Sabri SS, Saad W, Turba A, Park A, Angle J, Matsumoto A. “Percutaneous pulmonary embolectomy: Indications, techniques, and outcomes.” Vascular Disease Management. 2010; 7:E223-E229. http://www.vasculardiseasemanagement.com/content/percutaneous-pulmonary-embolectomy-indications-techniques-and-outcomes
Aymard T, Kadner A, Widmer A, Basciani R, Tevaearai H, Weber A, Schmidli J, Carrel T. “Massive pulmonary embolism: surgical embolectomy versus thrombolytic therapy – should surgical indications be revisited?” European Journal of Cardio-Thoracic Surgery.” http://ejcts.oxfordjournals.org/content/early/2012/03/29/ejcts.ezs123.full