analysis of lamb lung development with tracheal ligation in left posterolateral diaphragmatic hernia in cases and controls

background: when we perform surgery in utero, lungs have an appropriate time to decrease magnitude of hypoplasia, with surgery in uterus. methods: six time-dated single-fetus ewes were selected to induce diaphragmatic hernia. fetal lambs were divided proportionally into 2 groups, namely group 1, diaphragmatic hernia and tracheal ligation (tl group), and group 2, diaphragmatic hernia only (nl group). morphologic assessments (weight, volume, bronchiolar branching) and histological tests (lung maturation phase) were performed. results: lung weight in relation to lamb weight in the tracheal ligation group differed significantly from the control group (p<0.006 in the right lung and p<0.005 in the left lung). other parameters were markedly different between the two groups. lung volumes in relation to lamb weight were 29.88 â± 12.54 in the tracheal ligated group [tl] and 6.44 â± 1.84 in the non-ligated [nl] group in the right lung and 21.52 â± 7.58 in the tl group and 3.86 â± 1.90 in the nl group in the left lung. all parameters were in favor of tracheal ligation. lung maturation phase arrested in the canalicular phase in the nl group and continued to the saccular phase in the tl group. conclusions: tracheal ligation resulted in more mature lungs in the tl group. key words: congenital diaphragmatic hernia, tracheal ligation, sheep, lamb, fetal surgery.