RETROGRADE FLUSH AND COLD-STORAGE FOR 22 TO 25 HOURS LUNG PRESERVATION WITH AND WITHOUT PROSTAGLANDIN E-1

Background: Our previous study showed that retrograde flush through th e left atrium is better than antegrade flush in 6-hour lung preservati on. Whether it is feasible in long-term lung preservation is not clear . Several studies suggested that prostaglandin E-1 may not be necessar y in retrograde flush because of the low vascular resistance on the ve nous side. This study evaluates the effects of retrograde flush and pr ostaglandin E-1 in 24-hour lung preservation. Methods: Canine donor lu ngs were retrograde flushed with University of Wisconsin solution. Gro up A (n = 7) was pretreated with prostaglandin E-1. No prostaglandin E -1 was used in group B (n = 7). After flush and cold storage at 4 degr ees C for 22 to 25 hours, left lung allotransplantation was performed. Measurements were taken before transplantation (baseline), and at 10, 30, 60, and 120 minutes after transplantation while the right pulmona ry artery was occluded. Results: After 120 minutes of reperfusion, the oxygen tension and carbon dioxide tension were 643 +/- 24 and 37 +/- 3 mm Hg in group A and 600 +/- 29 and 37 +/- 3 mm Hg in group B, respe ctively (p = NS). Pulmonary artery pressure (group A vs group B) was 2 0 +/- 1 versus 28 +/- 2 mm Hg (p < 0.01); right atrium pressure: 4 +/- 1 versus 8 +/- 1 mm Hg (p < 0.01); left pulmonary vascular resistance : 1109 +/- 51 versus 1525 +/- 133 dyne.sec.cm(-5) (p < 0.05); airway r esistance: 22 +/- 1 versus 24 +/- 1 cm H2O/L/sec (p = NS); lung dynami c compliance: 30 +/- 1 versus 26 +/- 1 cc/cm (p < 0.05) respectively. As compared with the baseline (19 +/- 1), ainvay resistance was signif icantly increased after 2 hours of reperfusion in group B (p < 0.05). Electron microscopy revealed that type I pneumocytes, capillary endoth elial cells, and epithelial cells of bronchi were well preserved and t he contents of lamellar bodies of type II pneumocyte were reduced. Con clusions: Canine lung was well preserved by retrograde flush and cold storage with University of Wisconsin solution after 24 hours preservat ion. Pretreatment of prostaglandin E-1 is helpful in reducing pulmonar y vascular resistance and airway resistance and improving lung dynamic compliance.