Pneumonectomy: Background, Indications, Contraindications

The lungs are highly dynamic thoracic structures that are essential for respiration, pH equilibrium, enzyme production, and host defense, among many other functions. Thus, the lungs are susceptible to a wide variety of pathologic conditions, both malignant and benign, that may require pneumonectomy (complete resection of a lung).

Extrapleural pneumonectomy is an expanded procedure that includes resection of the parietal and visceral pleurae, diseased lung, ipsilateral hemi-diaphragm, ipsilateral pericardium, and mediastinal lymph nodes. While the procedure carries a risk of morbidity, including cardiac and pulmonary complications, it can be beneficial in patients with malignant mesothelioma and extensive thymomas. This surgical approach is often coupled with radiation and chemotherapy to improve survival in both diseases.

Sarot described the first extrapleural pneumonectomy in 1949, and it was initially used in the treatment of tuberculosis empyema but became more commonly used in the 1980s and 1990s in the treatment of mesothelioma.

Pneumonectomy

Indications

In general, pneumonectomy is indicated for both malignant and benign diseases.

Malignant indications for pneumonectomy include the following:

Pulmonary metastasis (uncommon)
Non-small cell lung carcinoma

Benign indications for pneumonectomy include the following:

Chronic lung infection (multiple abscesses, bronchiectasis, fungal infection, tuberculosis)
Traumatic lung injury
Bronchial obstruction with destroyed lung
Congenital lung disease

While the most common indication for an extrapleural pneumonectomy is malignant mesothelioma, the technique can also be used to treat disseminated thymomas and occasionally tuberculosis in a more limited fashion.

Contraindications

The patient’s pulmonary function should be assessed and a ventilation-perfusion scan considered for any patient with a forced expiratory volume in 1 second (FEV1) of less than 2 L. The combined results of these tests can be used to adequately predict postoperative lung function. Patients with a predicted postoperative FEV1 of less than 0.8 L are often treated with other means and not considered for pneumonectomy. Although surgeons base candidacy for extrapleural pneumonectomy on pulmonary function studies, patients should be individualized and performance status taken into account for resection.

Echocardiography may also be performed before the procedure to evaluate for valvular disease, pulmonary hypertension, and ventricular function. Severe valvular disease, confirmed severe pulmonary hypertension, and poor ventricular function may preclude surgery.

Positron emission tomography and CT scanning of the chest are used to assess the extent of disease involvement. Surgery is prohibited in patients with disease extending past the diaphragm to be intra-abdominal, to the contralateral hemithorax, invading into structures of the mediastinum or, most commonly, invading the ribs. Since chest MRI and CT scanning are unreliable determinates of chest wall invasion, this is also assessed intraoperatively.

Pneumonectomy

Technical Considerations

Anatomy

The lungs are two in number in the thorax and are separated by the mediastinum. The left lung is divided into two lobes, an upper and lower, by an oblique fissure, while the right lung is divided into 3 lobes (superior, middle, inferior) by an oblique and horizontal fissure. The right lung is heavier and has a larger capacity than the left lung yet is shorter in consequence of the liver.

Each lung is lined directly by serous membrane, creating the visceral portion of the pleura. The inner lining of the thorax is lined by the parietal portion of the pleura.

The hilum of the lung is a triangular depression on the mediastinal surface of each lung. It consists of pulmonary vessels, bronchi, and bronchial vessels and lymph nodes.