Assessment of forced expiratory volume in one second-fraction of the engrafted lung with 133-Xe radiospirometry improves the diagnosis of bronchiolitis obliterans syndrome in single lung transplant recipients.
BACKGROUND
Staging of bronchiolitis obliterans syndrome is based on the decline of forced expiratory volume in 1 second, a measure of overall ventilatory capacity. A single staging system is applied to all lung recipients, regardless of the bias which can be caused by the native lung after single lung transplantation.


METHODS
We determined the decline of graft function in single lung recipients by a combination of two methods: 133-Xe radiospirometry and dynamic spirometry. The forced expiratory volume in 1 second fraction of the transplant (FEV1tx) was calculated from the proportion of ventilation of the transplant (Vtx) and forced expiratory volume in 1 second. Eight single lung recipients were followed up for a median observation period of 17 months; bronchiolitis obliterans syndrome developed in four of them.


RESULTS
The fractional decline of forced expiratory volume in 1 second of the transplant was significantly greater than the decline of forced expiratory volume in 1 second (p = 0.016) in all patients during the follow-up. In the patients with bronchiolitis obliterans syndrome, the mean decline in forced expiratory volume in 1 second was 1.1 L (39.5%), and in forced expiratory volume in 1 second of the transplant it was 0.9 L (55.8%). The measurement of forced expiratory volume in 1 second of the transplant suggested stage 2a and 3a dysfunction in two grafts in which the assessment of forced expiratory volume in 1 second indicated stage 1a bronchiolitis obliterans syndrome. In one patient, decrease of forced expiratory volume in 1 second of the transplant was suggestive of chronic dysfunction 4 months before it was diagnosed by biopsy and declined lung function.


CONCLUSIONS
The assessment of forced expiratory volume in 1 second seems to underestimate the severity of chronic dysfunction in single lung grafts. Instead, the determination of forced expiratory volume in 1 second of the transplant with radioactive tracers provides selective information of the graft function, which could be used for clinical evaluation of bronchiolitis obliterans syndrome in single lung recipients.
Ikonen
T
T
Department of Thoracic and Cardiovascular Surgery, Helsinki University Central Hospital, Finland.
Harjula
A L
AL
Kinnula
V L
VL
Savola
J
J
Sovijärvi
A
A
D000328:Adult; D001989:Bronchiolitis Obliterans / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006084:Graft Rejection / Q000000981:diagnostic imaging*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D016040:Lung Transplantation / Q000009:adverse effects* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013147:Spirometry / Q000379:methods; D013997:Time Factors; D014692:Ventilation-Perfusion Ratio / Q000502:physiology; D014980:Xenon Radioisotopes
D014980:Xenon Radioisotopes