Lung and Heart-Lung Transplantation

Single lung transplantation requires posterolateral thoracotomy. The native lung is removed, and the bronchus, pulmonary artery, and pulmonary veins of the donor lung are anastomosed to their respective cuffs. The bronchial anastomosis requires intussusception or wrapping with omentum or pericardium to facilitate adequate healing.

Advantages of single lung transplantation include a simpler operation, avoidance of cardiopulmonary bypass and systemic anticoagulation (usually), more flexibility concerning size matching, and availability of the contralateral lung from the same donor for another recipient.

Disadvantages include the possibility of ventilation/perfusion mismatch between the native and transplant lungs and the possibility of poor healing of the single bronchial anastomosis.

Double lung transplantation requires sternotomy or anterior transverse thoracotomy; the procedure is similar to 2 sequential single transplants.

The primary advantage is definitive removal of all diseased lung tissue in the recipient.

The disadvantage is poor healing of the tracheal anastomosis.

Heart-lung transplantation requires median sternotomy with cardiopulmonary bypass. Aortic, right atrial, and tracheal anastomoses are required; the trachea is anastomosed immediately above the bifurcation.

The primary advantages are improved graft function and more dependable healing of the tracheal anastomosis because of coronary-bronchial collaterals within the heart-lung block.

Disadvantages include long operative time with the need for cardiopulmonary bypass, the need for close size matching, and use of 3 donor organs by one recipient.

A common 3-drug posttransplant immunosuppression Posttransplantation Immunosuppression Transplants may be The patient’s own tissue (autografts; eg, bone, bone marrow, and skin grafts) Genetically identical (syngeneic [between monozygotic twins]) donor tissue (isografts) Genetically... read more regimen combines

First, patients are given high doses perioperatively; methylprednisolone IV is often given intraoperatively before reperfusion of the transplanted lung. Lower doses are given for maintenance thereafter (see table Immunosuppressants Used to Treat Transplant Rejection Immunosuppressants Used to Treat Transplant Rejection ).

Antithymocyte globulin (ATG) or alemtuzumab is often given as induction therapy. These drugs can also minimize immunosuppressive therapy posttransplantation. Often, tacrolimus monotherapy is sufficient for maintenance therapy if induction therapy is given.

Corticosteroids may be omitted to facilitate healing of the bronchial anastomosis; higher doses of other drugs (eg, cyclosporine, azathioprine) are then used instead. Immunosuppressants are continued indefinitely.

Rejection Rejection Transplants may be The patient’s own tissue (autografts; eg, bone, bone marrow, and skin grafts) Genetically identical (syngeneic [between monozygotic twins]) donor tissue (isografts) Genetically... read more 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 > 10 to 15% (see table Manifestations of Lung Transplant Rejection by Category Manifestations of Liver Transplant Rejection by Category ).

Hyperacute rejection must 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, aerosolized cyclosporine, and ATG.

Chronic rejection develops 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, inhaled cyclosporine, and retransplantation.

The most common surgical complications are

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.