EXPIRATORY FLOW PATTERN FOLLOWING SINGLE-LUNG TRANSPLANTATION IN EMPHYSEMA

In single lung transplantation (SLT) recipients, a ''plateau'' of the maximal expiratory Row volume curve (MEFV) and a ''biphasic'' MEFV hav e been reported to reflect anastomosis pathology. A plateau is defined as constant airflow over a large expired volume early in the MEFV. A biphasic MEFV has an initial period of high flow followed by a termina l low flow phase. Models of expiratory flow limitation by wave speed, however, predict that the MEFV of SLT recipients with emphysema should both be biphasic and demonstrate a plateau even without anastomosis p athology. Review of the spirometries and clinical courses of our first ten patients receiving SLT for emphysema demonstrated a biphasic MEFV , and a plateau of the MEFV in all patients. No patient showed evidenc e of anastomosis pathology. Independent lung spirometries, generated b y a novel technique, revealed that the initial high flow phase of the MEFV came from the transplanted lung and the terminal low flow from th e native emphysematous lung. The location of the flow limitation was d emonstrated to be immediately downstream from the anastomosis. Therefo re, the MEFV of SLT recipients with emphysema routinely demonstrates b oth a biphasic pattern and a plateau, neither of which necessarily ref lect anastomosis pathology.