Bronchial Valve Surgery for Emphysema: What Surgeons Need to Know

Bronchial valve surgery, also known as endobronchial valve (EBV) implantation, is a minimally invasive procedure primarily used to treat patients with severe emphysema. This technique involves placing small, one-way valves in the airways to block airflow to the most damaged parts of the lung, allowing healthier lung tissue to expand and function more effectively. This article provides an in-depth overview of bronchial valve surgery, covering its indications, preoperative evaluation, contraindications, surgical techniques, postoperative care, complications, and recent advances.

Indications

Bronchial valve surgery is indicated for patients with severe emphysema, particularly those with heterogeneous disease where the damage is concentrated in specific lung regions. These patients typically experience:

• Persistent shortness of breath despite optimal medical therapy.
• A decline in quality of life due to reduced exercise tolerance.
• Frequent exacerbations of chronic obstructive pulmonary disease (COPD).

The ideal candidates for bronchial valve surgery are those with significant hyperinflation, where portions of the lung are overinflated, impairing the function of the remaining healthy lung tissue. Candidates should have undergone a comprehensive evaluation, including pulmonary function tests, high-resolution computed tomography (HRCT) scans, and possibly a ventilation-perfusion scan, to determine the best target areas for valve placement.

Preoperative Evaluation

The preoperative evaluation is critical to identify suitable candidates and optimize outcomes. This evaluation includes:

1. Pulmonary Function Testing (PFT): Spirometry, lung volume measurement, and diffusion capacity (DLCO) help assess the severity of lung impairment and guide patient selection.
2. Imaging Studies: HRCT scans are essential to identify target lobes with the most damage and assess collateral ventilation. Collateral ventilation, where air bypasses the normal airways, can render valve placement ineffective, as the air would continue to reach the diseased lobe.
3. Cardiopulmonary Exercise Testing: This test evaluates exercise capacity and helps predict postoperative improvement.
4. Six-Minute Walk Test (6MWT): A simple yet effective measure of functional status, this test can provide baseline data for comparison after surgery.
5. Arterial Blood Gases (ABG): ABG analysis helps assess the severity of hypoxemia and hypercapnia, which are common in advanced COPD.
6. Assessment of Collateral Ventilation: Techniques such as Chartis® Pulmonary Assessment System or equivalent methods can be used during bronchoscopy to determine the presence of collateral ventilation.

Contraindications

While bronchial valve surgery can be highly effective, it is not suitable for all patients. Contraindications include:

• Significant collateral ventilation: As mentioned, the presence of collateral ventilation can render the procedure ineffective.
• Severe pulmonary hypertension: High pressures in the pulmonary arteries can increase the risk of complications.
• Frequent lung infections: Recurrent or active infections increase the risk of post-procedural complications.
• Poor general health: Patients with severe comorbidities or those unable to tolerate anesthesia may not be suitable candidates.
• Extensive pleural adhesions: These can complicate the placement of the valves and reduce their effectiveness.

Surgical Techniques and Steps

Bronchial valve surgery is typically performed via bronchoscopy under general anesthesia or conscious sedation, depending on the patient’s condition and the complexity of the procedure. The steps include:

1. Patient Positioning and Anesthesia: The patient is positioned supine, and anesthesia is administered to ensure comfort and immobility during the procedure.
2. Bronchoscopy: A flexible bronchoscope is introduced into the trachea and advanced to the targeted lung lobe. Visualization of the bronchial tree is critical to identify the precise location for valve placement.
3. Collateral Ventilation Assessment: If not previously assessed, collateral ventilation is evaluated using devices such as the Chartis® system. This step is crucial to ensure that the target lobe is suitable for valve placement.
4. Valve Selection: The appropriate size and type of valve (e.g., Zephyr® or Spiration® valve) are selected based on the anatomy of the targeted airways.
5. Valve Placement: The selected valves are introduced through the bronchoscope and deployed into the target airways. The valves are designed to allow air to exit the lobe during exhalation but block air from entering during inhalation, leading to gradual atelectasis (collapse) of the diseased lobe.
6. Confirmation: Once the valves are placed, the bronchoscope is used to confirm correct positioning and assess any immediate complications.
7. Postoperative Bronchoscopy: A follow-up bronchoscopy may be performed in the same session or during a subsequent visit to ensure the valves remain correctly positioned and functional.

Postoperative Care

Postoperative care is crucial for optimizing outcomes and managing potential complications. Key aspects include:

1. Monitoring: Patients are monitored for respiratory function, oxygen saturation, and signs of complications such as pneumothorax (collapsed lung).
2. Pulmonary Rehabilitation: Early involvement in pulmonary rehabilitation can enhance recovery, improve exercise tolerance, and optimize lung function.
3. Medication Management: Patients typically continue their preoperative bronchodilator and corticosteroid therapy. Antibiotics may be prescribed prophylactically to prevent infections.
4. Follow-Up Imaging: Chest X-rays and HRCT scans are performed at regular intervals to monitor lung volume reduction and ensure proper valve placement.
5. Patient Education: Patients are educated on recognizing signs of complications, such as increased shortness of breath, chest pain, or fever, which should prompt immediate medical attention.

Possible Complications

Although bronchial valve surgery is generally safe, complications can occur, including:

• Pneumothorax: The most common complication, occurring in up to 20% of patients, often within the first 72 hours post-surgery. It typically results from rapid lung volume reduction and can range from mild to life-threatening.
• Valve Migration: Rare but possible, especially if the valve is not securely anchored. This may require repositioning or replacement.
• Infection: Postoperative pneumonia or bronchitis can occur, especially in patients with a history of frequent lung infections.
• Hemoptysis: Bleeding from the airways can occur, though it is usually self-limited and mild.
• Respiratory Failure: In severe cases, patients may experience worsening respiratory function, requiring mechanical ventilation or additional interventions.

Different Techniques

While the general approach to bronchial valve surgery is consistent, variations exist based on the specific valves used and the individual patient’s anatomy. The two most common types of valves are:

1. Zephyr® Valve: A one-way valve made of silicone and nitinol, designed to be inserted into airways to block inhalation but allow exhalation. It is the most widely used valve in the United States.
2. Spiration® Valve System (SVS): Another one-way valve with a unique umbrella design that fits into the airway, allowing air and mucus to escape while preventing air from entering.

The choice of valve may depend on factors such as airway size, the extent of emphysema, and the presence of collateral ventilation.

Prognosis and Outcome

The prognosis for patients undergoing bronchial valve surgery is generally favorable, especially in carefully selected candidates. The procedure can lead to significant improvements in lung function, exercise tolerance, and quality of life. Long-term follow-up studies have demonstrated sustained benefits for several years post-surgery.

However, the degree of improvement varies among patients. Those with more localized emphysema (heterogeneous disease) tend to experience better outcomes than those with diffuse (homogeneous) disease.

Alternative Options

For patients who are not candidates for bronchial valve surgery or who do not experience sufficient improvement, alternative treatment options include:

• Lung Volume Reduction Surgery (LVRS): A more invasive procedure that involves resecting the most damaged lung tissue to improve overall lung function.
• Lung Transplantation: Considered for patients with end-stage COPD who have exhausted other treatment options.
• Medical Management: Optimization of bronchodilator therapy, corticosteroids, and pulmonary rehabilitation remain cornerstones of COPD management.

Average Cost

The cost of bronchial valve surgery can vary widely depending on the healthcare system, geographic location, and specific patient factors. In the United States, the procedure can range from $20,000 to $40,000, including the cost of the valves, hospitalization, and postoperative care. Insurance coverage may vary, and patients should be informed of potential out-of-pocket expenses.

Recent Advances

Recent advances in bronchial valve surgery include:

• Improved Valve Designs: Ongoing research focuses on developing valves with better fit and reduced risk of migration or dislodgement.
• Combination Therapies: Studies are exploring the combination of bronchial valve surgery with other therapies, such as targeted pulmonary rehabilitation or pharmacological treatments, to enhance outcomes.
• Enhanced Imaging Techniques: Advances in imaging, including 3D reconstruction and functional lung MRI, are improving patient selection and the precision of valve placement.

Conclusion

Bronchial valve surgery represents a significant advancement in the treatment of severe emphysema, offering a minimally invasive option for patients who are not candidates for more invasive procedures. Careful patient selection, thorough preoperative evaluation, and meticulous surgical technique are essential to optimizing outcomes. As technology and techniques continue to evolve, the future of bronchial valve surgery looks promising, with the potential to benefit an even broader range of patients.