Fibrothorax is a condition characterized by accumulation of fibrous tissue in the pleural cavity in reaction to undrained pleural fluid. A thick “peel” is formed on both pleural surfaces, eventually preventing complete expansion of the lung. This basic premise explains several other names by which this condition is known: trapped or encased lung, organizing empyema (or hemothorax), and constrictive pleurisy. The process of removing the fibrous peel is called decortication. Delorme used the term for the first time in 1894.¹ The procedure was used primarily in the management of tuberculous pleurisy and later in the management of hemothorax.

The main causes of fibrothorax are listed in Table 132-1. The prerequisite for the formation of fibrothorax is the presence of undrained pleural effusion. The ensuing inflammatory response leads to fibrin deposition within the pleural space. This, in turn, is followed by infiltration of macrophages and fibroblasts and eventually formation of a collagen-rich “peel” that covers both the parietal and visceral pleurae and encapsulates the initial fluid collection (Fig. 132-1). At this stage, any attempts at management with thoracentesis are unsuccessful because the fluid quickly reaccumulates in the persistent cavity. Without remedial treatment, the initially thin peel continues to thicken, reaching depths of 2 cm or more.

Undrained pleural effusions also have a significant space-occupying effect and compress the underlying lung parenchyma. With continued organization of the fibrotic peel, the atelectatic portions of the lung become trapped. The same process occurs over the parietal pleura, both on the chest wall and on the diaphragm. The resulting physiologic changes are of the restrictive type. These effects are not always proportional to the thickness of the peel and can occur even with a limited extent of lung entrapment. Hypoxic pulmonary vasoconstriction limits blood flow and results in ventilation/perfusion mismatches. With unilateral disease, hypoxia may be absent at rest. The functional reserve is limited, however, and desaturation is seen with exercise.

The most frequent presentation is that of a patient with recurrent or persistent pleural effusion. Careful evaluation is warranted to determine whether fibrothorax is present or likely because this will influence the choice of appropriate management. Prior conditions leading to recurrent effusions and eventually an entrapped lung are often easily identified during history taking. A significant number of patients, however, may lack such a clear correlation. Depending on the underlying etiology and the degree of parenchymal involvement, symptoms may vary. Exertional dyspnea is the most common symptom, usually reported as progressive over a long period of time. Chest discomfort and nonproductive cough are also seen. The most common signs are limited respiratory movement of the affected hemithorax, decreased breath sounds on auscultation, and dullness to percussion.

Imaging techniques are of paramount importance. Standard chest radiographs (Fig. 132-2) demonstrate obliteration of the costophrenic angle and thickened pleural surfaces, initially seen over the diaphragmatic surface and the lateral chest wall, progressing superiorly and eventually obliterating the pleural space. The intercostal spaces may be narrowed, and the overall size of the hemithorax may be reduced. Pleural calcifications, when present, can help determine the thickness of the parietal peel.

CT scanning is essential in the evaluation of fibrothorax (Fig. 132-3). In addition to the information regarding the extent of the fibrotic process, the thickness of the peel, the presence of loculations, and potential differentiation from neoplastic pleural disorders (i.e., mesothelioma) are revealed. CT scanning provides useful information about the status of the underlying lung parenchyma. Tuberculous lesions, bronchiectasis, and underlying lung malignancies can be identified. In addition, a reasonable estimation of the effectiveness of the decortication can be made based on the extent of diseased lung parenchyma, which usually limits the postoperative expansion.

Pulmonary function studies should be obtained not so much for diagnostic purposes but primarily to quantify the degree of pulmonary impairment and serve as a measure of postoperative improvement. Perfusion scanning offers little additional information and is not performed routinely.

The best management for fibrothorax is prevention. Early and aggressive treatment of persistent pleural effusions, hemothorax, and empyema can avoid the development of the restrictive fibrous peel.^2,3 In the first several weeks, drainage usually is feasible either with tube thoracostomy or with thoracoscopic techniques and achieves excellent results. When treatment is delayed or unsuccessful, however, management decisions become more complicated. Both the need for a decortication and the optimal timing for the operation have to be determined. The decision to proceed with a decortication depends on several factors. The extent of the disease has to be such that it causes significant symptomatology and objective physiologic pulmonary impairment. Patients requiring decortication are those with at least 50% compression of the lung (especially with apical involvement), those with unsuccessful attempts at aspiration, and those with lack of improvement after 6 weeks of conservative management. The nature of the underlying disease is also important. In cases of empyema, failure of initial drainage usually is considered an indication for decortication; the goals of the operation in this setting are not only alleviation of lung constriction but also elimination of the infected pleural space by reexpansion of the lung. In the case of hemothorax, control of coagulation disorders must be addressed before extensive surgery. If the initial intervention has been tube thoracostomy, an early decision, within several days, should be made regarding the necessity of more aggressive surgical evacuation. In patients with tuberculosis, decortication is performed after completion of antituberculous chemotherapy and when there is considerable pleural involvement that does not change despite thoracentesis.