Surgery can have an important role within the treatment of malignant Mesothelioma in confirming the diagnosis, assessing the spread of the tumour (stage) and in the control of symptoms.
Surgery and Diagnosis
The diagnosis of malignant pleural Mesothelioma is made most firmly by the inspection of a biopsy of the pleura under the microscope. 
A diagnosis confirmed by biopsy helps when planning further treatment, for some treatments it is essential and it also verifies claims for compensation.
A diagnosis confirmed by biopsy helps when planning further treatment, for some treatments it is essential and it also verifies claims for compensation.It may be possible to obtain a reliable biopsy either by the removal of fluid from the chest (pleural fluid cytology) or a needle biopsy whereby a biopsy is obtained under local anaesthetic sometimes guided by a CT or ultra sound scanner. However, particularly in the early stages, negative results by these tests do not rule out the possibility of Mesothelioma. It may be felt that a surgical biopsy is warranted.
Picture Source - www.mayoclinic.org
There are two “keyhole” procedures that can be used. Under a local anaesthetic it is possible to have a medical thoracoscopy. This involves a small camera telescope being introduced through a single 1-2 cm cut from which a biopsy can be taken. If a general anaesthetic is performed, a thoracic surgeon may perform Video Assisted Thoracoscopic Surgery (VATS), through between 1 and 3 such cuts. This allows a larger biopsy to be performed and a full assessment of the pleura to be made.Video Assisted Thoracoscopic Surgery (VATS) - Picture Source - www.thoracicgroup.com
Staging
If the Mesothelioma is felt to be in an early stage and a surgical resection is being considered, it is essential to fully assess the tumour stage. This may require surgical biopsy of some of the lymph nodes in the centre of the chest (mediastinum). This may be achieved by a biopsy procedure called a mediastinoscopy. This involves a 4cm cut at the base of the neck, above the breast bone (sternum), and the introduction of a telescope (the mediastinoscope) down in front of the windpipe (trachea) into the chest.
Lung Diagram Picture Source - www.usctransplant.org
Radical Surgery
There are two approaches to surgical resection of malignant pleural Mesothelioma; radical and palliative.
The intention of radical surgery is to remove all or the majority of the visible tumour, dependent on which surgical procedure is carried out. With any cancer type radical surgery is performed with the aim of gaining local control in the area of the tumour, in patients in whom tests have not been able to demonstrate the spread of cancer cells elsewhere in the body. This, of course, cannot be guaranteed, as small deposits of cancer cells may be undetectable. With Mesothelioma, although wide margins of normal tissue around the removed cancer are difficult to achieve, the goal of local control can be obtained. It is important to remember that, unlike radical surgery in breast, bowel and lung cancers, where it is possible to offer the chance of a cure, this is not the case in Mesothelioma. No patient has yet been cured of the disease, even after radical surgery combined with chemotherapy and radiotherapy. Radical surgery is appropriate for only a small number of patients since the majority have disease that has already spread. However, palliative surgery may have an important role in improving and controlling symptoms and maintaining the quality of life. There are two radical surgical options - extrapleural pneumonectomy (EPP) and radical pleurectomy and decortication (P/D).
Radical Surgical Options
Extrapleural Pneumonectomy (EPP)
EPP was a procedure which gained initial favour amongst some surgeons in the UK and overseas, but it is now less commonly performed. It is the most aggressive surgical option but it is only appropriate for a very small number of patients. Pre-operative tests must demonstrate that patients have good, adequate lung and heart function before acceptance for surgery. EPP involves removing the entire lung and pleura together with the diaphragm and the side of the pericardium (the sac around the heart) in one piece. After removal of the tumour, the diaphragm and pericardium are reconstructed with artificial patches.
EPP was a procedure which gained initial favour amongst some surgeons in the UK and overseas, but it is now less commonly performed. It is the most aggressive surgical option but it is only appropriate for a very small number of patients. Pre-operative tests must demonstrate that patients have good, adequate lung and heart function before acceptance for surgery. EPP involves removing the entire lung and pleura together with the diaphragm and the side of the pericardium (the sac around the heart) in one piece. After removal of the tumour, the diaphragm and pericardium are reconstructed with artificial patches.
Lung-Sparing Total Pleurectomy (LS-TP)This procedure is also known as Radical Pleurectomy and Decortication (P/D). With LS-TP, the lung is left in place but the thickened pleural membrane covering it is peeled off and the pleura stripped off the chest wall. The pericardium and diaphragm are often removed, depending on the extent of the tumour. LS-TP is still, however, a very big operation that is only suitable for patients with sufficient reserves. As the lung remains in place, and it may even function better after surgery as it can often now expand more easily, recovery from surgery may be quicker and in the longer term quality of life may be preserved or even improved. However, compared to EPP, it slightly less likely to remove all the tissue that may contain tumour cells and therefore there is a greater chance of recurrence around the operated lung. In addition, it may not be possible to administer as high a dose of radiotherapy to the chest after the operation, as it may damage the underlying lung. LS-TP may be useful for patients in whom there is possible spread of the mesothelioma to the lymph glands in the centre of the chest (mediastinum). Not all thoracic surgeons in the UK have experience of this technique and some will prefer to operate after a few cycles of chemotherapy have been given.
Radical Pleurectomy and Decortication (P/D)
P/D is a less radical procedure than EPP and is generally better tolerated by patients. With radical P/D, the lung is left in place but the thickened pleural membrane covering it is skimmed off and the pleura stripped off the chest wall. The pericardium and diaphragm may be removed, depending on the extent of the tumour. As the lung remains in place, and it may even function better after surgery as it can often now expand more easily, recovery from surgery may be quicker. However, compared to EPP, it is not possible to remove all the tissue that may contain tumour cells and therefore there is a greater chance of recurrence around the operated lung. In addition, it may not be possible to administer as high a dose of radiotherapy to the chest after the operation, as it may damage the underlying lung. P/D may be useful in patients who are not fit enough to tolerate the loss of a lung, or those in whom there is spread to the lymph glands in the centre of the chest (mediastinum).
P/D is a less radical procedure than EPP and is generally better tolerated by patients. With radical P/D, the lung is left in place but the thickened pleural membrane covering it is skimmed off and the pleura stripped off the chest wall. The pericardium and diaphragm may be removed, depending on the extent of the tumour. As the lung remains in place, and it may even function better after surgery as it can often now expand more easily, recovery from surgery may be quicker. However, compared to EPP, it is not possible to remove all the tissue that may contain tumour cells and therefore there is a greater chance of recurrence around the operated lung. In addition, it may not be possible to administer as high a dose of radiotherapy to the chest after the operation, as it may damage the underlying lung. P/D may be useful in patients who are not fit enough to tolerate the loss of a lung, or those in whom there is spread to the lymph glands in the centre of the chest (mediastinum).
The Mesothelioma and Radical Surgery Trial (MARS)
Radical surgery will not result in a cure and it will reduce the immediate quality of life. One theory is that, following radical surgery, the progression of the disease would be slower, meaning patients would be better off in the medium and long term. By investigating in clinical trials the effects on the quality and length of life after radical surgery, compared to non-surgical treatment, it is hoped that evidence can be gathered to determine the value of surgery. The MARS trial was a study designed to examine the role of EPP in Mesothelioma. MARS has now closed to recruitment and its final results are awaited. The next part of the MARS trial will investigate LS-TP in a bigger study: funding for "MARS-2" is being sought.
Radical surgery will not result in a cure and it will reduce the immediate quality of life. One theory is that, following radical surgery, the progression of the disease would be slower, meaning patients would be better off in the medium and long term. By investigating in clinical trials the effects on the quality and length of life after radical surgery, compared to non-surgical treatment, it is hoped that evidence can be gathered to determine the value of surgery. The MARS trial was a study designed to examine the role of EPP in Mesothelioma. MARS has now closed to recruitment and its final results are awaited. The next part of the MARS trial will investigate LS-TP in a bigger study: funding for "MARS-2" is being sought.
Palliative Surgery
The type of operation depends on whether the lung on the affected side will expand or not. If after drainage of the fluid around the lung (pleural effusion) the lung will expand, then the options are either the insertion of sterile talc around the lung to seal the space between the pleural linings (pleurodesis) or the removal of the bulk of the tumour (pleurectomy). Both these procedures can be performed reliably by keyhole surgery Video Assisted Thoracoscopic Surgery (VATS). The MesoVATS trial is comparing outcomes of talc pleurodesis with VATS pleurectomy. Please refer to the Clinical Trials section of this website.
If, however, the lung is encased by tumour and cannot expand after fluid has been drained, then skimming the surface of the lung (decortication) will be required to make it possible for the lung to expand and thereby improve the function of the lung and improve shortness of breath. It is sometimes possible to decorticate the lung by VATS, but the majority of surgeons would perform decortication by opening the chest with a large cut made around the back below the shoulder blades, between the ribs this is called a thoracotomy. A trial to examine whether VATS decortication is worthwhile is being planned. Thoracotomy and decortication is a larger procedure reserved for the younger, fitter patients. In the elderly, more infirm patient, a tunnelled indwelling pleural catheter (TIPC) can be inserted. This is a permanent drain with a valve which empties the pleural fluid into a vacuum bottle, every few days as required.
Referral for Surgery
Patients can discuss the appropriateness of surgical treatment with the doctor who is currently caring for them. Not all hospitals are able to offer surgical treatment for Mesothelioma. Referral to other hospitals for treatment can be done by the hospital team currently caring for the patient or the GP where this is not feasible. Mesothelioma UK may be able to help identify the nearest surgical unit, where this is requested.
Conclusion
Surgery is frequently used across the UK to gain a diagnosis and treat pleural effusion. The provision of radical and palliative surgery may vary between parts of the UK and different hospitals. However, not all thoracic surgeons in the UK have experience of radical surgery for malignant pleural Mesothelioma and opinions can differ as to the benefits. It may be necessary for patients to be referred to a specialist centre.
0 comments
Posts a comment