550: Placebo controlled study on effect of intratracheal instillation of albumin prior to tracheal occlusion in nitrofen rats with CDH

Abstract

ALBUMIN PRIOR TO TRACHEAL OCCLUSION IN NITROFEN RATS WITH CDH PHILIPP KLARITSCH, LOURENCO SBRAGIA, JAAN TOELEN, STEFFI MAYER, XENIA ROUBLIOVA, JAN DEPREST, Katholieke Universiteit Leuven, Center for Surgical Technologies, Leuven, Belgium, University Hospitals Leuven, Pediatrics, Leuven, Belgium, University Hospitals Leuven, OB/GYN, Leuven, Belgium OBJECTIVE: Tracheal Occlusion (TO) promotes lung growth in fetuses with severe Congenital Diaphragmatic Hernia (CDH). Still 45% succumb, mainly to persistent hypoplasia. Lung response to TO may be enhanced by increasing lung liquid production by instilling an oncotic agent. We investigated the effect of albumin in addition to TO in a rat model for CDH. STUDY DESIGN: Time dated Wistar rats were fed nitrofen on E9.5. Only fetuses that had CDH at birth were taken into account. At E19 fetuses were assigned to four groups: 1:CDH fetuses who were left untouched; 2:TO fetuses i.e. CDH fetuses undergoing TO; 3: TOAlb i.e. TO fetuses with prior tracheal injection of 50 L of 20% albumin or 4: 50 il of 0.9%NaCl (TOSal). On E21.5 fetuses were harvested to measure wet lung-to-body-weight ratio (LBWR), airway morphometry (linear intercept (Lm; inversely related to air space size); mean terminal bronchiolar density (MTDB); septal thickness (Lmw). RESULTS: Lung to body weight ratio was higher in all TO groups, but in TO-Alb increase was the largest (p 0.05 ANOVA). TO decreases the number of respiratory bronchioli (ns for TOSal), coinciding with increased air space size (Lm), which was less prominent in TO rats. Decrease of septal thickness (Lmw) was equal in all TO groups. CONCLUSION: Fetal rats with CDH have hypoplastic lungs. TO reverses this, which is enhanced by 20% albumin but not placebo. This demonstrates that there is more than additional lung inflation by Sal/Alb next to effect of TO. The airway morphometry changes leave questions prompting for new studies with more sensitive measures of proliferation, interstitial changes and functional tests before implementation.