Mesothelioma Treatments: Curative Surgery – Extrapleural Pneumonectomy
Overview of Extrapleural Pneumonectomy
Pleural mesothelioma is a form of lung cancer that is almost always caused by asbestos exposure and is most commonly found in the outer lining of the lungs called the mesothelium. Although there are no cures for mesothelioma, it can be treated with varying degrees of success through the use of surgical procedures, chemotherapy and radiation.
Most often a diagnosis is not made until symptoms appear and the disease has progressed to an advanced stage leaving the patient with life-threatening complications. Early detection, however, can positively influence a patient’s prognosis by increasing treatment options and improving their quality of life while battling the cancer.
The goal of surgery is to achieve a macroscopically-complete resection, which refers to the removal of all visible tumor cells, however, the cancer often has a complex growth pattern making complete surgical removal a very difficult task.
An extrapleural pneumonectomy is a complex surgery for mesothelioma that features the removal of the affected lung and parietal pleura, as well as the possible removal of the diaphragm, the pericardium and other extrapleural tissue. The visceral pleura is attached to the lung and is therefore removed with it. Extrapleural pneumonectomy is an extensive and invasive surgery, but for the majority of patients with pleural mesothelioma, treatment protocols featuring it represent their best chance for long-term survival.
Pleurectomy-decortication is the other major surgical option.
Extrapleural Pneumonectomy – Overview of the Procedure
Extrapleural pneumonectomy (EPP) is considered radical surgery due to the extensive amount of tissue resection attempted during the procedure and the highly invasive techniques necessary to complete the operation. Patients who undergo the procedure face an extended recovery period and serious complications are not uncommon. However, EPP-based treatment protocols are often the most effective at increasing survival times and improving prognosis.
Extrapleural pneumonectomy requires a posterolateral thoracotomy for entry into the interior of chest. The incision is likely to be even more extensive than a standard thoracotomy incision and is done to give the surgeon greater exposure to the patient’s thorax. In some cases, the 6th rib may be removed to facilitate entry into the pleural cavity. When the surgeon reaches this area, he or she will then begin the actual resection.
The parietal pleura and the area surrounding it are the surgeon’s initial target, and then he or she will move to the lung itself. Once both of the lungs have been freed from their adjacent tissues, the surgeon will move on to the diaphragm and pericardium. The degree to which these structures will be resected depends on how extensively the disease has infiltrated them, as well as on the personal preference of the surgeon conducting the operation. Some physicians feel that both the diaphragm and the pericardium should be removed even if they do not show any signs of infiltration, while other surgeons feel they can be safely left alone if there is no evidence of malignancy. In most cases though, at least a partial resection of the diaphragm and pericardium is likely. If these structures are removed, they will be reconstructed using a mesh fiber that has been designed to replace the tissues and the supporting functions they previously performed.
At certain points during the procedure, the surgeon will also remove lymph nodes located in adjacent areas, as well in surrounding tissue structures, for post-operative staging analysis. The lymph nodes will be packaged and identified, and then sent to a pathologist for analysis. This information will inform the follow-up treatment options that the patient may undergo.
Once all of the tissues have been resected and the diaphragm and pericardium reconstructed if needed, the surgeon will begin the exit procedure. Complications are not uncommon with extrapleural pneumonectomies, so the surgeon will check to make sure that everything has been properly completed and is in the appropriate state. Drainage tubes will be inserted in various locations to ensure fluid dissemination from the pleural cavity and surrounding areas. This should enable proper lung expansion and will aid in patient recovery. Should everything be order, the surgeon will step backward through each of the steps made during the initial approach, reconstructing and reattaching tissues that had to be cut during entry and closing up incisions as he or she goes along.
After surgery, the patient will be moved into the Intensive Care Unit for a few days of monitoring and initial postoperative recovery. The first 3-5 days of postoperative care are exceptionally important to maximize a patient’s recovery and long-term health. Extrapleural pneumonectomy and thoracotomy are major operations and feature significant post-operative healing, so it is important for patients to take their recovery slowly.
Extrapleural Pneumonectomy – Treatment Considerations
Historically speaking, extrapleural pneumonectomy was associated with significant perioperative or postoperative mortality rates, as well as a high number of serious complications. Advances in surgical technique and greater experience with the procedure have significantly lowered the mortality figures, but serious complications are still possible. Mortality rates have now dropped below 5%, but serious treatment complications are commonly described in around 30% of cases.
Despite this high complication rate, surgeons generally feel that if a patient is a candidate for an EPP then the patient should definitely undergo the procedure. Most of the complications associated with extrapleural pneumonectomy are now fairly well-known, so even if surgeons aren’t able to prevent their occurrence, they are at least able to plan for the likelihood of occurrence and will be ready to adjust should one appear.
Extrapleural Pneumonectomy vs. Pleurectomy-Decortication
A recurrent question in mesothelioma treatment has been to what extent extrapleural pneumonectomy should be chosen over pleurectomy-decortication and what, if anything, it “means” to choose one procedure over the other. Many people have thought that the treatments were relatively interchangeable and that meant pleurectomy-decortication was then the “better” option because it preserves the lung, while extrapleural pneumonectomy was the “worse” option because it was more radical and could take longer to recover from. However, studies have generally concluded that the two procedures are not interchangeable: they have different domains of application and are most effective for patients in different stages of the disease. Pleurectomy-decortication is generally performed on patients who present with locally-contained asbestos cancer that only evidences a sparse advancement into adjacent tissues offering better relief of the symptoms, while extrapleural pneumonectomy is most-often used for patients who exhibit more extensive spread of the disease.
The goal of all curative surgeries for mesothelioma is to achieve a macroscopically-complete resection, so the procedure that can best achieve that is in fact “the better” procedure for an individual patient. During the disease’s earliest stages, a pleurectomy-decortication may be all that is needed to achieve macroscopically-complete resection. For patients lucky to be diagnosed with this limited tumor burden, pleurectomy-decortication is likely to be a good option. However, for patients who present with more extensive tumor infiltration—which is the majority of the diagnoses—extrapleural pneumonectomy will be the surgery of choice because it is more likely to achieve a macroscopically-complete resection than is a pleurectomy-decortication.
In many instances, a surgeon will not know which procedure will be performed upon beginning thoracotomy. If preoperative imaging scans show only sparse tissue infiltration, the surgeon may assume that pleurectomy-decortication will be performed, but if, upon entry into the pleural cavity, it is discovered that CT or MRI failed to disclose the extent of the malignancy, the surgeon will then attempt an extrapleural pneumonectomy. Although less likely, the opposite could be true as well: the surgeon may begin thoracotomy with the assumption of extensive tissue infiltration and, therefore, the performance of an EPP, but upon entry into the pleural cavity, the surgeon may see a smaller area of infiltration and a PD will be performed instead.
Extrapleural Pneumonectomy – Conclusion
Extrapleural pneumonectomy is the standard curative surgery in many of the multimodal treatment protocols currently under investigation for the treatment of pleural mesothelioma. Because the disease is most often diagnosed after it has had a chance to spread, an EPP represents the best chance that most patients have to achieve a macroscopically-complete resection, which is the end goal that most mesothelioma specialists have identified as the strategic point of surgery. Extrapleural pneumonectomy is not available to all patients, but for those who are eligible to receive it, a number of studies have shown that an EPP performed as part of a multimodal treatment protocol can lead to longer—sometimes, significantly longer—median survival times for these patients.
Related Information: Mesothelioma & Surgery
For more information related to surgical treatment, please read the following:
- Mesothelioma Treatments: Surgery
- Mesothelioma Treatments: Curative Surgery – Pleurectomy-Decortication
- Mesothelioma Treatments: Palliative Surgery – Debulking Pleurectomy
- Mesothelioma Treatments: Palliative Surgery – Decortication of the Lung
- Mesothelioma Treatments: Palliative Surgery – Pleural Catheters and Pleuroperitoneal Shunts
- Mesothelioma Treatments: Palliative Surgery – Pleurodesis
- Mesothelioma Treatments: Surgical Techniques – Thoracotomy
- Mesothelioma Treatments: Surgical Techniques – Video-Assisted Thoracoscopic Surgery (VATS)