Introduction
Balloon pulmonary angioplasty is an interventional technique that is minimally invasive. It is performed to treat chronic thromboembolic pulmonary hypertension. It is an emerging treatment option for patients who are not eligible for surgery or have residual pulmonary hypertension. This procedure uses a balloon to open the narrowed blood vessels and restores the blood flow to the lungs, reducing shortness of breath.
What Is Chronic Thromboembolic Pulmonary Hypertension?
Chronic thromboembolic pulmonary hypertension is a condition in which there is an increase in blood pressure in the small blood vessels of the lungs. This increase in pressure is due to scarring or the presence of blood clots. In pulmonary hypertension and chronic thromboembolic pulmonary hypertension, the blood pressure is high on the right side of the heart. This results in the conservation of oxygen-poor blood. Therefore, the heart works harder to push it out of the lungs. Also, blood takes a longer time to travel through the lungs, causing reduced oxygen levels.
The pressure is high if the narrowing is severe. It results in shortness of breath, chest pain, cyanosis (bluish discoloration of the skin), hemoptysis (coughing up blood), palpitations, fatigue, dizziness, pedal edema (swollen legs due to fluid buildup), and reduced physical activities. If left untreated, it can result in right heart failure and death due to the risk of progressive pulmonary hypertension. Chronic thromboembolic pulmonary hypertension is treated with pulmonary endarterectomy or pulmonary balloon angioplasty. Pulmonary endarterectomy is an open surgical procedure that is performed to remove the blood clots from the arteries of the lungs, whereas balloon angioplasty is a minimally invasive procedure that opens up the narrowed arteries.
What Is Balloon Pulmonary Angioplasty?
Balloon pulmonary angioplasty is an interventional procedure that uses a balloon catheter (a hollow and partially flexible tube) to dilate the narrowed pulmonary vessels, thereby improving pulmonary pressure and perfusion. It is a peripheral interventional technique that removes multiple clots from the pulmonary arteries (which supply the lungs). It was first developed for the treatment of congenital hypoplastic and stenotic arteries in the field of pediatric cardiology. Since 1988, pulmonary balloon angioplasty has been used to treat chronic thromboembolic pulmonary hypertension cases that are not eligible for pulmonary endarterectomy.
A pulmonary embolus or embolism refers to blood clots in the lungs. Patients with chronic thromboembolic pulmonary hypertension have multiple pulmonary emboli in their lungs. These blood clots may cause the development of scar tissue in the pulmonary arteries over a period of time. The scar tissue in the pulmonary artery increases arterial blood pressure and restricts the blood flow to the lungs, thereby reducing the oxygen supply. A pulmonary balloon angioplasty uses catheters and small balloons to push the obstructing clots and scar tissue aside to restore blood flow. This reduces the symptoms of shortness of breath and allows the patient to perform physical activities. It improves blood flow, heart function, and the ability to perform exercises.
What Are the Indications for Balloon Pulmonary Angioplasty?
Balloon pulmonary angioplasty is indicated for patients not eligible for pulmonary endarterectomy. It is also indicated in patients with recurrent or residual pulmonary hypertension after surgical correction with pulmonary endarterectomy, as repeated surgery is complex. In this technique, individual arteries are examined and evaluated for indication of balloon pulmonary angioplasty depending on the type of the lesion, extent, and location of the lesion. However, each artery is examined to indicate pulmonary balloon angioplasty while performing pulmonary balloon angioplasty.
The Japanese circulation society stated the following indications for balloon pulmonary angioplasty:
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Ineligible cases for pulmonary endarterectomies, such as surgically inaccessible lesions, inoperable lesions due to comorbidities, and residual or recurrent pulmonary hypertension after pulmonary endarterectomy.
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Cases in which conventional therapies are not sufficient.
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Patients who provide informed consent for balloon pulmonary angioplasty after understanding the risks and benefits of balloon pulmonary angioplasty and pulmonary endarterectomy.
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Cases without any complications, iodine allergies, or multiorgan failure.
What Are the Contraindications for Balloon Pulmonary Angioplasty?
Contraindications of balloon pulmonary angioplasty include iodine allergy and renal dysfunction. The patient's age should also be considered because of the safety and efficacy of balloon pulmonary angioplasty in elderly patients.
How Is Balloon Pulmonary Angioplasty Performed?
The balloon pulmonary angioplasty technique requires a venous approach through either the right internal jugular vein or the right femoral vein to guide the catheter into the right or left pulmonary artery. A guidewire and a catheter are used to access the pulmonary arteries. A balloon catheter of size 0.0591 to 0.394 inches diameter dilates the lesion once the guiding wire successfully crosses the lesion. For one treatment session, the target area is limited to two segments on the same side to reduce the risk of lung injury. The target areas for treatment depend on the operator and the lesion's location, distribution, and type.
What Is the Difference Between Pulmonary Endarterectomy and Balloon Pulmonary Angioplasty?
Pulmonary endarterectomy involves the removal of the thrombi (blood clot) from the inside of the pulmonary arteries, whereas pulmonary balloon angioplasty does not include the removal of the thrombi. In this technique, a balloon catheter is used to push the clot aside to make the lumen of the artery more significant. Though the thrombi are not extracted in balloon pulmonary angioplasty, restenosis does not occur because the organized thrombi partially detach from the vascular wall, and this wall undergoes thinning and expands over time and prevents restenosis.
What Are the Complications of Balloon Pulmonary Angioplasty?
A significant complication associated with pulmonary balloon angioplasty is lung injury. In severe lung injury cases, percutaneous cardiopulmonary support and mechanical ventilation are essential. Though pulmonary balloon angioplasty is a minimally invasive technique, lung injuries are reported in 9.6 percent to 60 percent of the cases. Other complications like pulmonary artery perforation and vessel rupture are also reported. These complications may require emergency transcatheter embolization or the use of covered stents. In addition, this procedure is also associated with fatal complications like pulmonary edema.
Conclusion
Balloon pulmonary angioplasty is an exclusive interventional procedure with excellent outcomes. This technique reduces the symptoms of shortness of breath and dizziness and restores the physical activities of the patients. It potentially improves the hemodynamics in patients with chronic thromboembolic pulmonary hypertension who are ineligible for pulmonary endarterectomy.
