immunology allergic disorders
Lung and Heart Lung Transplantation
Complications of Lung and Heart Lung Transplantation
(See also Posttransplantation Complications .) Rejection develops in most patients despite immunosuppressive therapy. Symptoms and signs are similar in hyperacute, acute, and chronic forms and include fever, dyspnea, cough, decreased SaO2 (arterial oxygen saturation), and a decrease in FEV1 by Hyperacute rejectionmust be distinguished from early graft dysfunction caused by ischemic injury during the transplantation procedure, and acute rejection must be differentiated from infection. Interstitial infiltrate, seen on chest x-rays, is typical in patients with accelerated or acute rejection. Rejection is usually diagnosed by bronchoscopy, including bronchoscopic transbronchial biopsy. If rejection has occurred, biopsy shows perivascular lymphocytic infiltration in small vessels; polymorphonuclear leukocytes in alveolar infiltrates and infectious pathogens suggest infection. IV corticosteroids are usually effective for hyperacute, accelerated, or acute rejection. Treatment of recurrent or resistant cases varies and includes higher corticosteroid doses, aerosolizedcyclosporine, and ATG. Chronic rejectiondevelops after>1 year in up to 50% of patients; it manifests as obliterative bronchiolitis or, less commonly, as atherosclerosis. Acute rejection may increase risk of chronic rejection. Patients with obliterative bronchiolitis present with cough, dyspnea, and decreased FEF25-75% (forced expiratory flow during expiration of 25 to 75% of the forced vital capacity) or FEV1, with or without physical and radiographic manifestations . Differential diagnosis includes pneumonia. Diagnosis is usually by bronchoscopy with biopsy. No treatment has proved effective, but options include corticosteroids, ATG, inhaledcyclosporine, and retransplantation. Rejection Category Manifestations Hyperacute Poor oxygenation, fever, cough, dyspnea, decreased FEV1 Accelerated Poor oxygenation, fever, cough, dyspnea, infiltrate seen on chest x-ray, decreased FEV1 Acute Same as those for accelerated Interstitial perivascular infiltrate (detected by transbronchial biopsy) Chronic Obliterative bronchiolitis, cough, dyspnea FEV1 = forced expiratory volume in 1 second. The most common surgical complications are Poor healing of the bronchial or tracheal anastomosis (diagnosed when mediastinal air or pneumothorax is detected) Infection Up to 20% of single-lung recipients develop bronchial stenosis that causes wheezing and airway obstruction; it can be treated with dilation or stent placement. Other surgical complications include hoarseness and diaphragmatic paralysis, caused by damage to the recurrent laryngeal or phrenic nerves; gastrointestinal dysmotility, caused by damage to the thoracic vagus nerve; and pneumothorax. Supraventricular arrhythmias develop in some patients, probably because of conduction changes caused by pulmonary vein-atrial suturing. 