Am. J. Respir. Crit. Care Med., Vol 150, No. 6, Dec 1994, 1684-1689.
Expiratory flow pattern following single-lung transplantation in emphysema
JP Herlihy, JG Venegas, DM Systrom, RE Greene, KA McKusick, JC Wain and LC Ginns
Lung Transplantation Program, Massachusetts General Hospital, Boston 02114.
In single lung transplantation (SLT) recipients, a "plateau" of the maximal
expiratory flow volume curve (MEFV) and a "biphasic" MEFV have 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 terminal 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 pathology. 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 evidence of anastomosis pathology.
Independent lung spirometries, generated by a novel technique, revealed
that the initial high flow phase of the MEFV came from the transplanted
lung and the terminal low flow from the native emphysematous lung. The
location of the flow limitation was demonstrated to be immediately
downstream from the anastomosis. Therefore, the MEFV of SLT recipients with
emphysema routinely demonstrates both a biphasic pattern and a plateau,
neither of which necessarily reflect anastomosis pathology.
