Malignant disease of the pleura encompasses a wide scope of clinical presentations ranging from asymptomatic simple pleural effusions to complex tumor masses involving multiple intrathoracic organs. The treatment options are similarly diverse. This chapter focuses on the indications, techniques, and results of pleurectomy and decortication (P/D) in the management of malignant pleural disease.

Pleural malignancies can be classified as primary, arising from the pleura, or secondary, that is, metastatic. Primary pleural malignancies include malignant pleural mesothelioma (MPM) and malignant localized fibrous tumors of the pleura. Metastatic pleural disease is a common clinical problem. Although lung and breast cancers are the most common primary tumors, virtually any cancer can metastasize to the pleura.

Although primary pleural tumors have been reported since the eighteenth century, the epidemiology of mesothelioma first came to light in 1960 with the report by Wagner et al.¹ of 33 asbestos mine workers from South Africa who developed mesothelioma. Pleural mesothelioma previously was classified as benign or malignant. However, recognition that “benign” or “localized” mesothelioma has a biology that is distinct from MPM led to a change in nomenclature. These benign tumors are now termed solitary fibrous tumors of the pleura.

MPM is a rare tumor. Although the geographic distribution of the disease is diverse, taken as a whole, the United States has an incidence just under 1 per 100,000 persons.² The incidence has been rising since the 1970s. The male-to-female ratio is 5:1, which is likely reflective of occupational exposure to asbestos.

The clinical presentation of MPM is usually insidious. The most common presenting symptoms are dyspnea and chest pain.

Staging in MPM, as is the case in other aspects of the disease, lacks consensus. Various staging systems exist. The classic system described by Butchart et al. in 1976 is relatively simple and descriptive.³ The Brigham staging system is based on resectability by extrapleural pneumonectomy (EPP) and may not be of value in patients undergoing P/D.⁴ The tumor, node, metastasis (TNM) staging system proposed by the International Mesothelioma Interest Group (IMIG) is the accepted American Joint Commission on Cancer staging system.⁵

Indications for Surgery

In the days before effective systemic therapy, MPM was thought to be uniformly fatal. Surgery was reserved for diagnosis and palliation. In the first reports of “curative” surgery, Butchart et al.³ performed EPP with a surgical mortality rate of 30%. In the nearly 30 years since the initial report, advances in patient selection, as well as intra- and postoperative management, have decreased the mortality of the operation substantially, as reported by centers with high volumes of mesothelioma surgery. Sugarbaker et al.⁶ reported their mortality rate from 183 consecutive EPPs performed at the Brigham and Women’s Hospital as 3.8%. At Memorial Sloan-Kettering, Flores reported a 5.2% mortality for EPP.⁷ The staggeringly high mortality rate seen in early attempts at EPP led to a movement away from this operation and toward P/D as a method of debulking tumor. The mortality of P/D is reported to be 1.8%,⁸ and the lack of evidence demonstrating superiority of EPP over P/D is thought to be a consequence of the upfront mortality increase with the more extensive operation.

There are those who still believe that surgical intervention for purposes other than palliation in mesothelioma is not indicated. Although it is true that there are no randomized controlled trials comparing surgical treatment with supportive care (or other treatments) in these patients, the reality is that these trials likely will never be performed. For those who treat this disease and have a less nihilistic outlook, surgery forms a key component of the treatment algorithm.

Nomenclature

There has been a move in the international mesothelioma community to standardize the terminology associated with the disparate operations performed by various surgeons under the umbrella heading of P/D. This should enable improved analysis of results across various centers and enable more coordinated research efforts, as to date, the majority of reports and studies are single center in origin. Recommendations published jointly by the International Association for the Study of Lung Cancer (IASLC) and the IMIG following a survey suggested that the term P/D be used to denote attempted complete removal of macroscopic tumor from the visceral and parietal pleura and the term extended P/D be used if the diaphragm and pericardium are removed as well.⁹

Indications for P/D

Indications for P/D can be regarded as patient-related or tumor-related. Perhaps the least controversial statement one can make about P/D is that it can be offered to patients who do not have the cardiopulmonary reserve to tolerate pneumonectomy. For patients who can tolerate pneumonectomy, the choice of operation becomes less clear. Some centers perform P/D for patients with early-stage disease, that is, confined to the parietal pleural “capsule” (Butchart I, IMIG T1a or T1b), with the rationale that if no lung parenchyma is involved, the inherent morbidity and mortality risk of adding a pneumonectomy is not warranted. Others disagree, based on the rationale that the absence of lung parenchyma facilitates the administration of postoperative adjuvant radiotherapy.

If one accepts that MPM is a disease where true R0 resections are a theoretical achievement, then the goal of surgery is to remove all gross tumors and serve as a springboard for adjuvant therapy. The choice of operation then is made based on the extent of resection required and the extent of resection the patient can tolerate. Some clinicians believe that with newer methods of radiation administration and ongoing attempts at other local and systemic therapies, the argument that residual lung parenchyma hinders appropriate adjuvant therapy may be less of a factor than it once was.¹⁰

We reported a retrospective study of 663 patients (385 had EPP and 278 had P/D) which demonstrated a hazard ratio of 1.4 for EPP when controlling for stage, histology, gender, and multimodality therapy. Clearly the study is subject to selection bias, but this reinforces our view that P/D may be the optimal procedure if adequate debulking can be performed by leaving the lung parenchyma in place.¹¹

Preoperative Evaluation

All patients undergoing consideration for P/D need thorough imaging and cardiopulmonary evaluation. At a minimum, pulmonary function testing should be performed. Quantitative ventilation/perfusion scans may also be indicated if associated lung resections are anticipated or to evaluate the possibility of EPP. Computed tomography (CT) scanning of the thorax and upper abdomen is required, and magnetic resonance imaging (MRI) may be superior in assessing discrete focuses of chest wall invasion or diaphragmatic muscle involvement.¹² However, rarely does MRI change surgical management. Fluorodeoxyglucose positron emission tomography (PET) scanning in MPM can be used to provide stage and prognostic information. In addition to helping to determine the extent of tumor, PET scanning can be used to detect N3 or M₁ disease in 10% of patients.^13,14 The standardized uptake value also can be used to predict the presence of N2 lymphatic spread.¹⁴ High standardized uptake value also has been shown to correlate with poor survival in MPM.¹⁵

Another controversial question in the preoperative evaluation of patients is the role of mediastinoscopy in MPM. It is useful in determining the N stage of most patients and is more accurate than CT scanning.¹⁶ However, up to 25% of patients have lymph node involvement confined to areas of the hemithorax inaccessible by mediastinoscopy, such as the peridiaphragmatic and internal mammary regions.⁷ Furthermore, although N2 disease does negatively impact survival, some feel that it should not be used as the sole reason to deny surgery.

Technique

After the induction of general anesthesia, a double-lumen endotracheal tube should be inserted to facilitate the operation. An arterial line and central venous pressure monitoring are important because blood loss is often significant (approximately 1–2 L). The patient is placed in the lateral decubitus position, and a long S-shaped posterolateral thoracotomy incision extending downward to the costal margin is made (Fig. 121-1). The sixth rib is resected, and the dissection is begun in the plane between the endothoracic fascia and the parietal pleura (Fig. 121-2). The pleural tumor is bluntly dissected away from the chest wall. The plane is then developed in a cephalad direction toward the apex from the posterolateral direction. Care in identifying the subclavian vessels is prudent because a traction injury to these structures is difficult to repair (Fig. 121-3). As each area of dissection is completed, packs are placed to aid in hemostasis because a fair amount of blood loss will result from the blunt dissection. The dissection then is continued inferior and posterior to the incision. After a sufficient area of chest wall has been mobilized, a chest retractor may be inserted.

The pleura now can be mobilized from the mediastinum. Once the upper portion of the lung is completely mobilized from the chest wall, the superior and posterior hilar structures are well exposed. On the left side, the esophagus and aorta must be identified and the dissection around them should be undertaken with care. On the right side, the superior vena cava must be dissected away from the specimen gently. The dissection then continues to the posterior aspect of the pericardium. A plane between the mediastinal pleura and the pericardium is sometimes present. If it is not, the pericardium needs to be resected en bloc at a later stage of the operation with subsequent reconstruction. The dissection then is carried toward the posterior diaphragmatic sulcus. If superficial involvement of the diaphragm is found, a partial-thickness resection can be performed. The plane between the tumor and the uninvolved diaphragm can be entered, and the dissection is initiated at the posterior costophrenic angle and carried anteriorly. This is facilitated by strong retraction on the pleura away from the diaphragm. In many patients, deeper involvement of the diaphragm mandates a full-thickness resection of a portion of the muscle. The deep border of the diaphragm then must be dissected from the peritoneum. Care should be taken to avoid entering the abdomen because tumor seeding into the peritoneal cavity is a concern. This is often unavoidable, especially around the central tendon, and any defect in the peritoneum should be closed immediately. The specimen then is mobilized en bloc back toward the pericardium medially. If resection of the pericardium is required, it is delayed until the tumor is mobilized as much as possible owing to the accompanying arrhythmias from manipulation. The pericardium is opened gradually, and traction sutures are placed on the nonspecimen edge to maintain the position of the heart and to prevent retraction of the pericardium into the opposite hemithorax (Fig. 121-4).

Once the dissection is completed to the hilar structures, the parietal pleura is opened, and the pleural envelope is entered and decortication of the visceral pleura is performed. This is, in some respects, the most technically demanding and tedious component of the operation. Decortication must be performed with care into the fissures because they are often substantially involved with disease (Fig. 121-5). During the decortication, deflation of the lung will minimize blood loss, and inflation will allow better visualization of the plane between the tumor and the visceral pleura or lung parenchyma. Communication with the anesthesiologist about the amount of blood loss is important because most patients require intraoperative transfusion.

Lymph node dissection should be carried out, and specimens should be labeled and sent separately to the pathologist. The subcarinal lymph nodes should be resected as well as the paratracheal lymph nodes on the right and the aortopulmonary lymph nodes on the left.

Once the gross tumor is removed and the specimen is delivered, reconstruction of the pericardium and diaphragm, if required, is performed. If the diaphragm is largely intact, it can be closed primarily by plication to prevent upward movement and subsequent compression atelectasis of the lower lobe. On the right side, reconstruction of the diaphragm is performed with a double layer of Dexon (United States Surgical, Syneture Division, Norwalk, CT) mesh because the liver prevents herniation of intra-abdominal contents. On the left, 2-mm-thickness Gore-Tex (W.L. Gore and Associates, Flagstaff, AZ) is used because thicker, nonabsorbable material is required to prevent herniation. The prosthesis is secured laterally by placing sutures around the ribs. Posteriorly, it is sutured to the crus or tacked to the prevertebral fascia. The medial aspect is sewn to the remaining edge of the diaphragm at its confluence with the pericardium. The diaphragmatic prosthesis should be made absolutely taut to prevent upward motion of the abdominal contents and subsequent atelectasis of the lower lobe. If the pericardium was resected, it is reconstructed with a single layer of Dexon mesh.

Attention is now turned to obtaining hemostasis. An argon beam electrocoagulator may be used to help control diffuse bleeding from the chest wall. Three chest tubes are placed anteriorly and posteriorly into the apex, and a right-angle tube is placed along the diaphragm. This should permit control of the substantial air leaks that are anticipated and should permit full expansion of the lung. The air leaks tend to resolve after 72 hours if the lung is fully expanded.