53. Lymphangioleiomyomatosis
Definition
Lymphangioleiomyomatosis (LAM) affects women during the childbearing years. It is characterized by proliferation of smooth muscle phenotypic neoplastic cells in the lungs, kidneys, and axial lymphatics. The proliferation results in cystic destruction of the lung with progressive pulmonary dysfunction and abdominal tumors.
Incidence
The incidence of LAM is unknown. More than 500 cases had been documented in the United States as of 2006.
Etiology
The etiology of LAM is unknown. The disease occurs predominately in premenopausal women and seems to be exacerbated by elevated estrogen states, suggesting that female hormones may have a prominent role in the cause.
Signs and Symptoms
• Chest pain
• Chylothorax
• Chylous ascites
• Chyluria (chyle in the urine)
• Cough
• Dyspnea
• Lymphedema
• Pleural effusions
• Pneumoperitoneum
• Pneumothorax(-aces)
Medical Management
Generalized medical care of the patient with LAM is directed toward treatment of specific symptoms.
Pleural effusions may be treated with chemical pleurodesis or surgical obliteration of the pleural space. Pulmonary dysfunction is treated with good, generalized pulmonary care incorporating bronchodilators and supplemental oxygen. In extreme circumstances, lung transplantation may be considered.
Ascites may be treated with paracentesis to remove the fluid.
Hormonal manipulation has been advocated. Medroxyprogesterone and gonadotropin-releasing hormone agonists have been advocated, but case reports are inconclusive. More recent experimental drug therapies include sirolimus, doxycycline, and octreotide.
Complications
• Benign metastasizing leiomyoma
• Bronchiolitis
• Diffuse pulmonary lymphangiomatosis
• Eosinophilic granuloma
• Interstitial pulmonary fibrosis
• Leiomyosarcoma
• Lymphangiomas
• Pleural effusion(s)
• Pneumothorax
• Pulmonary lymphangiectasis
• Smooth muscle cell proliferation in the lung
• Tuberous sclerosis
Anesthesia Implications
Malnutrition and immunocompromise are two concerns in the patient with LAM presenting to the OR. Malnutrition carries with it a host of associated problems, including electrolyte imbalances, low levels of serum proteins, lipid imbalances, altered energy reserves, altered protein synthesis, myocardial dysfunction, and loss of muscle strength. Preoperative laboratory studies must necessarily concentrate on evaluating levels of electrolytes, serum proteins, and glucose as well as bleeding times (PT, PTT, and bleeding time) to give the anesthetist an opportunity to initiate corrective measures. Sodium and potassium imbalances may require intravenous supplementation along with infusion of solutions containing 5% albumin and glucose. Hypolipidemia may be treated with a lipid infusion. The low level of serum proteins and altered protein synthesis may adversely affect the patient’s ability to synthesize necessary clotting factors. The patient may require infusion(s) of fresh frozen plasma to supplement the serum proteins and to temporarily enhance the patient’s clotting factors. As a result of the altered protein synthesis and the subsequent alteration in clotting factors, the anesthetist should anticipate greater blood loss than would otherwise be expected for a particular surgical procedure.
The patient’s state or degree of malnutrition may have a significant impact on her wound healing ability. If possible, elective surgery should be postponed to allow for several days of hyperalimentation to improve her nutritional state.
The degree of immunosuppression may be tied to the patient’s nutritional status. Improvement of the patient’s nutritional status may rebuild the patient’s immune status.
LAM is associated with development of chylothorax (-thoraces). Elective surgery should be postponed until any chylothorax present can be drained and a chest tube(s) secured in place. The presence of chylothorax can produce significant atelectasis, which in turn results in ventilation/perfusion (V/Q) mismatch. This mismatch causes altered gas exchange. Thoracentesis to drain any chylothorax allows for re-expansion of the atelectatic areas but can also increase the V/Q mismatch in the affected area until the re-expanded area’s ventilation improvement “catches up” with the improved perfusion. For this reason, preoperative thoracentesis should precede any surgery by several hours, if not a full day. Because of the patient’s altered gas exchange, several drugs must be avoided. These drugs—which reduce hypoxic pulmonary vasoconstriction, thus worsening gas exchange and lowering arterial O 2 content—include nitroprusside, nitroglycerin, β 2-agonists, nitric oxide, and nimodipine.
LAM also affects the lung by producing a mixed obstruction/restrictive pulmonary disease. Preoperative evaluation of the patient’s pulmonary status is important and must include pulmonary function tests (PFTs), arterial blood gas analysis, and chest x-ray. Intraoperative ventilation should incorporate methods to lower inspiratory pressure and allow for prolonged expiratory time, the goal being to reduce the possibility of air trapping and potential pneumothorax development. Because of the association of pneumothorax with LAM, patients who do not have a chest tube in place before anesthesia should not receive nitrous oxide as part of the anesthesia plan.
Because of the significant detrimental effects on the lungs produced by LAM, both the anesthetist and the patient should discuss the possible need for postoperative ventilatory support. The pulmonary damage, along with the malnutrition status and extensive nature of the surgery, may require that the patient remain intubated and sedated long enough to build up sufficient energy reserves to accomplish the work of breathing.
The kidneys may also be significantly altered by LAM. Blood urea nitrogen, serum creatinine, and urinary output are indicators of renal function. Fluid restrictions may be necessary when parameters indicate some degree of renal dysfunction.
Placement of an arterial pressure catheter may be prudent and convenient for the patient with LAM. This monitoring device will enable serial arterial blood gas sampling for analysis as well as assessment of fluid and electrolyte status, particularly during extensive procedures.
