Diffuse Pleural Mesotheliomas - Diffuse Malignant Mesotheliomas
Earlier studies in patients requiring pleurectomy (but not having mesothelioma) had an in-hospital or operative mortality of 10 to 18% in the 1960s.23b,131a The modern-day mortality from pleurectomy has decreased and is generally considered to be 1.5 to 2%, with death either from respiratory insufficiency or hemorrhage. Most recently, associated with profound blood loss and potentially significant cardiac demands. The patient should be carefully screened for a history of hypertension, angina, previous myocardial infarction, and routine electrocardiograms should reveal no signs of previous injury.
Rationale of Surgery. It is difficult to imagine that any diffuse pleural mesotheliomas are amenable to en bloc removal. A small proportion of tumors called mesotheliomas may present as an encapsulated mass, not associated with pleural effusion, and these may be amenable to surgical extirpation with negative margins of resection. The majority of diffuse malignant mesotheliomas, however, cannot be surgically removed en bloc with truly negative histologic margins because many of the patients have had a previous biopsy and there is invasion of the endothoracic fascia and intercostal muscles at that site and/or there is pleural effusion which, although cytologically negative, may be breached, leading to local permeation of tumor cells, either into the residual cavity or into the abdomen. Nevertheless, it is encouraging that in the largest series of EPP performed for mesothelioma from the Boston group, 66 of 183 patients were defined as having negative resection margins after EPP. Patients with this finding who had epithelial mesothelioma were found to have 2- and 5-year survival rates of 68% and 46%, respectively, if the node dissection did not reveal tumor.257a
The operation of choice, especially for early pleural mesothelioma, has yet to be defined. There is no doubt that EPP is a more extensive dissection and may serve to remove more bulk disease than a pleurectomy, chiefly in the diaphragmatic and visceral pleural surfaces.Some surgeons, however, will include diaphragmatic resection and pericardial resection with their pleurectomies to accomplish removal of 'all gross disease." For EPP, it is almost a necessity to include pericardiotomy, with or without resection, for the maneuver aids in the exposure of the vessels and allows intrapericardial control to prevent a surgical catastrophe.
There are no real guidelines preoperatively that one can use to assure the patient which operation will be necessary to accomplish tumor removal. The presence of irregular, bulky disease, on the CT scan, that infiltrates into the fissures probably dictates the necessity for EPP; a large effusion with minimal bulk disease may call for pleurectomy decortication. Moreover, the philosophy of the surgeon regarding the operation may impact on his choice, for some surgeons reserve EPP for those patients with bulky disease that prevents simple pleurectomy, while others feel that the greatest chance for complete gross excision will be via EPP performed in the patient with minimal disease. This important factor "preoperative quantitative bulk of disease" may not only influence the choice or resection but may be an important preoperative prognostic factor in any patient with DMM, as described above.195b
Pleurectomy. When performed routinely, pleurectomy for mesothelioma can be associated with few major complications. In the series that specify postoperative morbidity, the most common complication was prolonged air leak for > 7 days, occurring in 10% of the patients. On average, the chest tubes can be removed in approximately 5.5 days with > 50% of the patients having the chest tube removed within 4 days. Pneumonia and respiratory insufficiency may occur and is usually related to the burden of disease and preoperative functional total pleurectomy performed in 50 patients for mesothelioma had a 30-day mortality of 2%. In a recent series of 39 pleurectomies, the hospital mortality was 0%.195c
Pleurectomy and decortication are very effective in controlling malignant pleural effusion. Law reports effusion control in 88% of patients having decortication for mesothelioma.152 In 63 patients having partial decortication and pleurectomy, Ruffie225 reported 86% control of effusion, and Brancatisano37a reported a 98% control of effusion after pleurectomy in 50 cases of pleural mesothelioma.
Many of the published series using pleurectomy for palliative management have added therapies postoperatively in an uncontrolled, institution-related fashion. The majority have had no sampling of the mediastinal nodes, little less a mediastinal dissection. Nevertheless, the overall median survival for patients having pleurectomy alone is approximately 13 months. The patients who receive pleurectomy and decortication alone usually have early effusive disease with minimal bulk tumor. If these patients have epithelial mesothelioma and are not found to have nodal involvement, survival rates can be significantly longer than that quoted above.