Management of LAM
Kidney tumors called angiomyolipomas, unusual hamartomas containing fat, smooth muscle and blood vessels, are present in about 90% of patients with TSC and 30%-50% of sporadic LAM. Hemorrhage into an angiomyolipoma can produce symptoms from chronic intermittent flank pain to acute abdomen with hypovolemic shock.
Pleural Complications in LAM
Pneumothoraces ultimately occur in approximately 60-70% of patients with LAM and the rate of recurrence is over 70%; the highest among all chronic lung diseases. The average number of subsequent pneumothoraces for those who have had a sentinel pneumothorax is 4.4. The average lifetime pneumothorax-related burden for LAM patients with a history of pneumothorax who responded to a LAM Foundation questionnaire was approximately 3.5 events, 5 interventions, one month in the hospital and $75,000 in estimated hospital costs. The recurrence rate following conservative therapy such as aspiration or chest tube drainage is about 66%, and following chemical or surgical pleurodesis are 27% and 32%, respectively. It is unclear why the recurrence rate following pleural fusion is so much higher for LAM than for other cystic lung diseases, such as Langerhan's cell histiocytosis, but it is possible that the remarkable profusion of cysts on the surface of the LAM lung prevents apposition and fusion of the lung and the parietal pleura. The LAM Foundation Pleural Disease Consensus Committee recommended ipsilateral pleurodesis with the initial pneumothorax in each hemithorax, although when surveyed patients often preferred a more conservative approach. Chylous pleural effusions occur in about one third of patients and may be unilateral or bilateral. Pleurodesis is generally an effective approach for chylothorax, but less invasive treatments such as thoracentesis or observation may suffice in some cases.
Caring for Patients with Lymphangioleiomyomatosis (LAM)
As LAM is a very inconsistent disease with some patients remaining stable over many years and other declining more rapidly, may clinicians do not treat asymptomatic LAM patients with any specific therapy until it is clear that they have progressive disease. Although patients with LAM have been managed empirically with anti-estrogen therapies, there is no proof that these strategies are effective and few physicians would now regularly start patients on hormonal treatment for LAM. Progestins can cause fluid retention and mood swings, and the benefits of Gonadotropin-releasing hormone agonists are unproven. Induction of early menopause is distressing and morbid in young women. There is no proven role for corticosteroids, immunomodulatory cytoxic agents or ovarian irradiation in the treatment of LAM. Oophorectomy is no longer recommended because the benefits are unknown and the risk of bone and heart disease is increased. More recently evidence has been accumulating that drugs like sirolimus may prevent decline in lung function and possibly improve chylous complications in some patients. At present, in the face of therapeutic uncertainty, the patient and physician should make all treatment decisions jointly, after thorough discussion of the risks and limited available data.
Role of Hormones in Women with LAM
Since LAM occurs almost exclusively in women of reproductive age, researchers believe the hormone, estrogen, might be involved in the abnormal muscle cell growth that characterizes the disease. Although there is no direct evidence that there is a relationship between estrogen and LAM, the treatment of LAM has focused on reducing the production or effects of estrogen. Additionally, doctors believe pregnancy may accelerate the progression of LAM. The risk of pregnancy in LAM has not been rigorously studied. However, it is likely that pregnancy can increase the risk of pneumothorax occurring and these may be more difficult to treat. Pregnancy may also be associated with the increased growth and bleeding in angiomyolipomas and possibly accelerated decline in lung function. Although women with LAM may have successful pregnancies, pregnancy may be more of a risk for those with poor lung function. The physician and patient should discuss the risks of pregnancy carefully and decisions should be made on an individual basis.
Other Pulmonary Management Issues
Patients with LAM should avoid exposure to tobacco smoke.
Bone Disease Management
Bone densitometry should be considered in all patients who are immobilized and/or on antiestrogen therapies. Calcium and bisphosphonate therapy should be considered in osteoporotic patients. Proper attention should be paid to cardiovascular health in patients who are rendered menopausal by therapy.
LAM and Airtravel
Many LAM patients have been advised to avoid air travel because of the theoretical risk of lung cyst rupture associated with atmospheric pressure changes during flight. In a questionnaire study of 276 patients who had taken 454 flights, Pollock-Bar Ziv et al found that air travel is generally well tolerated by most patients with LAM. Symptoms of anxiety, chest pain, shortness of breath, cyanosis or hemoptysis occurred in 10-20% of flights. Pneumothorax occurred in 10 flights, including eight episodes that were radiographically documented, but in five cases symptoms suggestive of pneumothorax were present prior to boarding. There have been no airtravel-associated incidents requiring hospitalization among the over 500 LAM patients who have participated in the decade-long NHLBI protocol, which has encouraged visits every six months. Airtravel, however, was not recommended to all patients. If patients have a newly diagnosed pneumothorax, complete resolution for at least two weeks prior to flying is recommended based on expert opinion and limited available data. In any patient with symptoms suggestive of a new pneumothorax, appropriate radiologic testing should be performed prior to air travel which based on available data may require a CT scan of the thorax as pneumothoraces may not always be seen on a chest Xray.