109: Lung Transplantation Technique

Introduction

Since its inception in 1963, over 32,000 lung transplants have been performed globally. For several decades, chronic obstructive pulmonary disease (COPD) was the most common indication for lung transplantation. However, in the United States, the donor lung allocation system has changed the scenario and idiopathic pulmonary fibrosis (IPF) is emerging as a more common indication. IPF accounts for about 25% of lung transplant at our center and 33% nationally.¹ Cystic fibrosis (CF) is the third most common indication.

To be eligible for bilateral lung transplantation, potential transplant recipients should be without significant comorbid disease. Patients with emphysema generally are older than other patient groups (e.g., CF) and thus perhaps are more at risk for cardiovascular or cerebrovascular events. In contrast, CF patients often have occult renal insufficiency secondary to years of antibiotic therapy, particularly with aminoglycosides. Unique infectious concerns are also seen in the CF population because these patients frequently are infected with one or more strains of Pseudomonas aeruginosa and often are colonized with mycobacterial or fungal pathogens. Furthermore, CF patients often have a degree of liver disease, pancreatic insufficiency, or both owing to the multiorgan system effects of the CF genetic defect. Patients with primary pulmonary hypertension (PPH) commonly have residual right-sided heart dysfunction immediately after transplantation and need greater attention to cardiac hemodynamics, often requiring an increase of right-sided filling pressures for hemodynamic stability. Finally, the widespread use of IV prostacyclin (Flolan) has permitted many patients with PPH to delay transplantation. Thus, by the time these patients present for transplant, the degree of right-sided heart failure is often quite severe.

Choice of Transplant

The decision to perform a single-, double-, or heart–lung transplant depends on numerous factors, including recipient characteristics (e.g., disease, age, and comorbidities), institutional bias, organ availability, and the urgency of the transplant. Single-lung transplantation is a good option for patients with IPF.² Selected patients with emphysema, specifically those of shorter stature and older age, also can expect good results with single-lung transplantation. Unilateral transplantation is also acceptable for patients with PPH.³ However, because these cases are challenging and management can be difficult during the first few postoperative days,⁴ some programs prefer the double-lung or even combined heart–lung transplantation for patients with PPH. Double-lung transplant is mandatory for patients with CF and bronchiectasis because in both cases the septic native lungs must be excised. When the native disease is accompanied by a pre-existing mycetoma⁵ or other chronic fungal or mycobacterial infection, double-lung transplantation is also a better option because it minimizes the post-transplant risk of recurrent infection. The heart–lung transplant is reserved for the rare patient with combined end-stage cardiac and pulmonary disease. Most patients requiring heart–lung transplant have Eisenmenger syndrome with PPH and significant left ventricular dysfunction, perhaps owing to an uncorrected congenital defect. The annual rate of heart–lung transplantation has declined significantly not only because single- or double-lung transplant alone ...