In a study titled Surgical Treatment of Malignant Pleural Mesothelioma published online April 5, 2011 in Current Treatment Options in Oncology, authors Andrew Kaufman and Raja Flores note that even though surgery is an accepted form of treatment for pleural mesothelioma, controversy still exists as to whether it really does increase change of survival and whether extrapleural pneumonectomy or pleurectomy/decortication is more effective in increasing those chances.
The problem, as the explain it, is that there are no randomized clinical trials comparing extrapleural pneumonectomy and pleurectomy/decortication, which means that there isn’t a lot of evidence to support either technique. The two operations are quite different. A pleurectomy/decortication is a two part procedure; the first part involves the surgical removal of the pleura that lines the chest wall and the pleura over the sac around the heart, the cavity between the lungs and the diaphragm. The decortication is the surgical removal of the pleura that covers the diseased lung; however, the lung remains intact.
An extrapleural pneumonectomy is far more radical in its approach because the diseased lung is removed along with the pleura the lines the chest wall, the pleura that covers the lung, lymph nodes in the cavity between the lungs, the sac around the heart and most of the diaphragm.
The authors added, however, that in spite of the controversy over techniques, there is agreement as to the goal of surgery, which is complete removal of the tumor if possible, or at least removal of as much of it as can be removed to make chemotherapy and radiation more effective.
How this is accomplished “depends on multiple factors including: disease stage, the patient’s cardiopulmonary reserve, surgeon experience and philosophy, and the extent of planned adjuvant (secondary) therapy.”
Mesothelioma Surgery for Peritoneal Mesothelioma
This form of mesothelioma originates in the abdominal cavity and its progression is primarily in that area. Given this characteristic of the disease, the treatment is designed to control progression in the abdominal cavity.
In a study titled Surgery for Peritoneal Mesothelioma, published online March 29, 2011 in Current Treatment Options in Oncology, authors Keli M Turner, Sheelu Varghese and H Richard Alexander note that the treatment most commonly used is removal of as much of the tumor as possible along with hyperthermic intra-operative perfusion of intraperitoneal chemotherapy (HIPEC).
The HIPEC procedure is performed directly following the tumor removal. For a maximum of two hours, a sterile solution containing a chemotherapy drug that is heated to a temperature above the normal body temperature is circulated in the abdominal cavity. The purpose is to destroy any disease that was not removed surgically.
This combination of surgery and HIPEC can be used alone, or in combination with abdominal chemotherapy administered after the surgery, or as part of a multi-modality therapy that includes surgery/HIPEC and abdominal chemotherapy and radiation of the whole abdomen administered after surgery.
Mesothelioma Surgery Achieves Good Outcomes in Some Patients
According to these authors, there have been instances of patients surviving for up to seven years after the surgery/HIPEC procedure. Factors that influence a good outcome include being female, 60 years old or younger, and the complete removal of the disease. In patients with ascites, or a buildup of fluid in the abdominal cavity, complete alleviation of this symptom is achieved in almost all cases. However, this treatment regimen carries substantial risk. The chance of developing another medical condition is 25 percent and there is a seven percent risk of dying.
“Despite these risks, the best overall survival data have been associated with this surgical approach.”
Extrapleural Pneumonectomy
For mesothelioma treatment, extrapleural pneumonectomy surgery involves involving complete removal of the lung containing the tumor along with both the pleural layer that lines the chest cavity and the pleural layer that covers the lung, most of the diaphragm on the affected side and a part of the nerve that controls the movement of the diaphragm.
Extrapleural Pneumonectomy for Debulking of the Mesothelioma Tumor
When doctors talk about cytoreduction in reference to a malignancy, they are referring to debulking a tumor, which cannot be completely removed. By making the tumor smaller, it enhances the effectiveness of chemotherapy and/or radiation treatments that will be given after the surgery. Extrapleural pneumonectomy is the type of mesothelioma surgery used for cytoreduction. Even though the surgery is extremely complex, survival is possible, but it is dependent on a number of factors.
In a study titled Clinical and pathological features of three-year survivors of malignant pleural mesothelioma following extrapleural pneumonectomy, published online February 8, 2011 in the European Journal of Cardiothoracic Surgery, researchers examined the International Mesothelioma Program Patient Data Registry at Brigham and Women’s Hospital to find all patients who underwent extrapleural pneumonectomy for malignant pleural mesothelioma between January 1, 1988 and May 31, 2007. They identified 636 patients, 117 survived at least 3 years following surgery, including 26 remaining alive and four lost to follow-up.
The researchers observed that among the 3-year survivors, 39 were women, 61had left-sided tumor, and the average age was 56 years. In fact, more of the survivors were at the average age or younger, were women, had a tumor made up of epithelial cells, and/or had normal white blood cell count, hemoglobin, or platelet count before the operation. The average survival time of the 117 patients who survived for three years or more was 59 months. However, the researchers noted that a significant association between age and survival was found for women. No such association existed for men who underwent extrapleural pneumonectomy.
Based on their findings, the researchers concluded that:
A significant proportion of patients undergoing extrapleural pneumonectomy for pleural mesothelioma experienced extended survival. Although favorable prognostic features were more common, the cohort of 3-year survivors included a substantial number of patients with late-stage disease. The longest survival (median greater than 7 years) was experienced by women under the median age of 56 years.
They also felt that the evidence supported the use of extrapleural pneumonectomy for debulking a large portion of the tumor as part of a multi-modality therapy, meaning using more than one treatment, to extend survival for malignant pleural mesothelioma.
Extrapleural Pneumonectomy to Relieve Mesothelioma Symptoms
A major symptom associated with pleural mesothelioma is what is known as dyspnea, or shortness of breath. A form of dyspnea, called orthopnea, which is difficulty breathing unless sitting/standing upright, can also be a symptom. Extrapleural pneumonectomy has been used to relieve, or palliate, these symptoms. However, a new study questions the benefit of such extreme surgery for symptom improvement given its high mortality rate and rate of disease recurrence.
The study titled Extrapleural pneumonectomy or supportive care: treatment of malignant pleural mesothelioma, published online March 8, 2011 in Interactive CardioVascular and Thoracic Surgery, researchers looked for studies comparing extrapleural pneumonectomy and other forms of treatment for symptom remediation. They found 14 they felt provided the best evidence to answer the question of whether or not extrapleural pneumonectomy was the superior form of treatment.
Of the 14 studies, 10 evaluated the role of extrapleural pneumonectomy. The average survival time of these patients was 13 months with a 5.7 percent mortality rate between the time after surgery and the conclusion of hospital stay, and 9.1 percent mortality rate after 30 days. There was a high rate of disease including atrial fibrillation, pus buildup in the space between the lung and the chest wall and irregular heartbeat in the tissue above the ventricles. The disease recurred in 73 percent of the patients after an average period of 10 months.
Three months after surgery, symptoms had improved in 68 percent of the patients.
Two studies examined outcomes after chemotherapy. The average survival time was 13 months and symptoms improved in 50 percent of patients. The average time until the disease progressed was 7.2 months. The conditions that resulted from this treatment included an abnormally low level of white blood cells, anemia, and an abnormally low level of platelets.
The final two studies talked about symptom remediation by methods other than extrapleural pneumonectomy. The average survival for patients in these studies was seven months and symptoms were improved in 25 percent one year after treatment. The 30-day mortality rate was 7.8 percent and complications included prolonged air leak and pus buildup in the space between the lung and the chest wall.
Pleurectomy
Mesothelioma surgery pleurectomy is used to remove the pleural layer that lines the chest wall, the area of the thoracic cavity between the lungs, the sac surrounding the heart, and the diaphragm. The second part of this procedure is called a decortication, which means to remove the outer covering of an organ. In this case the visceral pleura, or the part of the pleura that covers the lung, is removed.
Pleurectomy for Relief from Mesothelioma Symptoms
This type of mesothelioma surgery can be used for cytoreduction that is debulking the tumor. However, even though the tumor is made smaller, some residual tissue remains. That is why pleurectomy is not considered a curative procedure and it is used as part of a multi-modality therapy, meaning the patient receives chemotherapy and/or radiation after the procedure.
In a study titled Is pleurectomy and decortication superior to palliative care in the treatment of malignant pleural mesothelioma? published online February 22, 2011 in Interactive CardioVascular and Thoracic Surgery, researchers looked for studies that helped them determine if pleurectomy is the better method for alleviating symptoms compared to other forms of treatment.
The studies they found that reported patient outcomes after use of radical pleurectomy/decortication showed a higher average survival than other supportive care and non-radical decortication. However, radical pleurectomy/decortication had a 30 percent complication rate, required a hospital stay of 12 days, and had an operative mortality rate of 9.1 percent. One-year survival rate was 65 percent.
The studies that examined the use of chemotherapy to relieve symptoms showed that the average survival rate was 14 months for those who received chemotherapy early as compared with 10 months for those patients that delayed treatment. Patients with early chemotherapy also had an average of 25 weeks before disease progression and a 66 percent one-year survival rate.
The evidence presented from their examination of these studies led the researchers to conclude:
P/D (pleurectomy/decortication) is a morbid operation that is associated with significant perioperative mortality (death occurring in the time between the surgery and release from the hospital) and complication rates. Although a number of retrospective studies have shown a small benefit in survival with P/D, the heavily documented similarity in patient outcomes between P/D and extrapleural pneumonectomy along with the results of the Mesothelioma and Radical Surgery trial, should induce the surgical community to consider the use of P/D only in patients with malignant mesothelioma enrolled in prospective trials.
Recurrence of Mesothelioma After Pleurectomy
In this type of mesothelioma surgery, disease typically returns in an area local to the original disease site. For that reason, pleurectomy is combined with other therapies to increase survival time.
In a study titled Extrapleural pneumonectomy versus pleurectomy/decortication in the surgical management of malignant pleural mesothelioma: results in 663 patients, published March 2008 in the Journal of Cardiovascular and Thoracic Surgery, researchers conducted a multi-institutional study to find patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy or pleurectomy/decortication. They identified 538 men and 125 women who underwent either type of mesothelioma surgery between 1990 and 2006. The average age of the patients was 63 years old.
Three hundred and eighty-five patients underwent extrapleural pneumonectomy and 278 underwent pleurectomy/decortication. Twenty-seven of the extrapleural pneumonectomy patients died and 13 of the pleurectomy/decortication patients died.
Although patients who underwent pleurectomy/decortication had a better survival rate than those who underwent extrapleural pneumonectomy, there were a number of factors that influenced this including the stage of the cancer, the type of cells within the tumor, the gender of the patient and whether or not the patient received other forms of therapy after the mesothelioma surgery.
This evidence led the researchers to conclude that, “At present, the choice of resection (type of surgery) should be tailored to the extent of disease, patient comorbidities (other existing health conditions), and type of multimodality therapy planned.”
Pleurodesis
Pleurodesis is a form of mesothelioma surgery that is used to manage pleural effusions, a very common problem in patients with pleural mesothelioma. A pleural effusion is a buildup of fluid between the parietal pleura that lines the chest wall and the visceral pleura that covers the lung. This fluid buildup stops lung function, causing shortness of breath, or dyspnea.
How is mesothelioma surgery used to achieve pleurodesis?
The fluid is drained in one of two ways: the first is by tube thoracostomy. In this procedure, a chest tube between 20 to 24 French (F) is used. The French scale is the method used to measure the diameter of a catheter. In this system, 1F= 0.33 millimeters (mm), so the tube that will be inserted is between 6.7 mm and 8 mm in diameter.
The tube is usually inserted in the 5th or 6th intercostal space, which is the space between the 5th and 6th rib, counting down from the collar bone. It is done through a 2 centimeter incision in the midaxillary line. Doctors use an imaginary “map” of the chest area in order to describe it for clinical purposes. On the side of the chest, there are three vertical lines, the middle line is the midaxillary line.
The second procedure to drain fluid is a video-assisted thoracoscopy. In this procedure, a surgical tool that has a triangular point, called a trocar, is inserted into the intercostal space through an incision in the skin. This allows a thin, tube-shaped instrument called a thoracoscope to be inserted. The thoracoscope has a light and a telescopic lens to see inside the chest and it can also have a tool to remove tissue. Additional incisions are made to allow for the insertion of other necessary instruments to perform the procedure.
After fluid is drained, an irritant is introduced into the space between the pleural layers either by injecting it in or by blowing it in. The most commonly used irritant is sterile talc, which is asbestos-free. It is usually administered either as a powder or slurry, meaning the powder is suspended in liquid.
The success of this procedure is compromised if there is an extremely large tumor in the space between the pleural layers, or if the lung is trapped by a thick visceral pleural peel of tumor.
Is pleurodesis the best way to treat pleural effusions?
In a study titled What is the best treatment for malignant pleural effusions? published online February 16, 2011 in Interactive Cardiovascular and Thoracic Surgery, researchers looked for previously published studies to help them determine if pleurodesis is a better treatment option than catheter drainage or pleuroperitoneal shunts in the management of patients with pleural effusions. A pleuroperitoneal shunt is a tube implanted surgically that carries fluid from a pleural space into the abdominal cavity, where it is absorbed.
They found 14, which they felt best answered the question. Six studies reported patient outcomes after pleurodesis. There was an 89.4 percent success rate in relieving symptoms and only a 2 percent mortality rate. The average hospital stay was 2.33 days with a complication rate of 16.5 percent. Length of survival after the procedure averaged 23.8 months.
Five studies reported patient outcomes using chronic intrapleural catheters. There was a 94.2 percent success rate in relieving symptoms, a 7.5 percent mortality rate, and a complication rate of 22 percent. The average survival length was 126 days. However, even in patients with trapped lung syndrome, the average survival length with this procedure was 125 days with a 90.9 percent success rate in relieving symptoms.
Three studies reported patient outcomes using pleuroperitoneal shunts. The success rate for symptom alleviation varied from 57.1 percent to 95 percent with a complication rate of 14.8 percent. The average hospital stay was 6.2 days with an average survival time of 11 months.
The evidence led researchers to conclude that, “Overall, chemical pleurodesis is the optimal treatment option for MPE (malignant pleural effusions) with use of chronic intrapleural catheters reserved in cases where talc pleurodesis is not possible.”
Thoracentisis
The fluid that is removed from the pleural space during this procedure can be used for diagnostic purposes, or it can be done to relieve shortness of breath. Occasionally, pleurodesis, a procedure to introduce an irritant, like talc into the drained pleural space to stop fluid buildup from recurring, will be performed as part of the thoracentisis.
How is Thoracentisis Performed?
This type of mesothelioma surgery can be performed on an outpatient basis. Before the thoracentisis, the doctor will confirm the location of the fluid through the use of a physical examination and a chest x-ray. However, the patient may also need to undergo a CT scan and/or an ultrasound if a previous thoracentisis attempt failed, or if the fluid is loculated, meaning it is trapped inside little pockets of tissue.
The patient is usually sitting upright and leaning slightly forward with a support under the arms. A local anesthetic called lidocaine is injected into the skin to anesthetize it. Another needle containing more lidocaine is injected into the upper border of the rib that is one intercostals space below the fluid. An intercostals space is the space between two ribs.
The lidocaine is injected in intervals, as the needle goes more deeply into the chest. The major portion of the anesthetic is injected into the parietal pleura, the part of the pleura that lines the chest wall. The needle is moved past the parietal pleura until fluid is aspirated.
A thoracentesis needle combined with catheter is attached to a 3-way stopcock. A stopcock is a special valve that controls the flow of liquid. The needle-stopcock is attached to a 30- to 50-mL (milliliter) syringe and tubing. The needle is moved through the skin into tissue along the upper border of the rib that is just below the fluid until it reaches the fluid buildup. The catheter is inserted through the needle, and the needle is removed.
As the fluid is drained, the stopcock is used to stop/start the flow so that the fluid can be collected in different receptacles to be evaluated later. The fluid can only be removed at a rate of 1.5 liters per session. If it is removed at any faster rate, it could cause low blood pressure or a buildup of fluid in the air sacs in the lungs.
The thoracentisis is usually followed by a chest x-ray to be sure the patient does not have pneumothorax, a condition in which air from the lungs leaks into the pleural cavity and compresses the lung. The x-ray is also used as an indication of how much fluid was removed and to look at the areas of the lung’s surface that were hidden by the fluid.
Coughing is a common side effect of this mesothelioma surgery. It typically occurs when the lung re-expands after the thoracentisis. If the two layers of the pleura are inflamed, the patient may also experience pain and hear a rubbing sound as the fluid is drained because the inflammation has enlarged the parietal and visceral pleura so much that they are now touching.