EFFECT OF INTRAUTERINE REPAIR OF DIAPHRAGMATIC-HERNIA ON THE ACCOMPANYING PULMONARY HYPOPLASIA IN THE FETAL RABBIT

Severe pulmonary hypoplasia precluding the sustenance of life is often found in newborns with prenatally diagnosed congenital diaphragmatic hernia (CDH). Ln utero repair of the hernia it is thought to be the so le method of salvaging these patients. To study the efficacy and feasi bility of in utero repair of CDH, diaphragmatic hernias (DH) were prod uced successfully in 81 of 90 fetal rabbits by diaphragmatic perforati on via a left thoracotomy at 22 days' gestation (term = 31 days). The DHs were repaired successfully in 25 of 50 fetal rabbits at 26 days' g estation. The rabbits with repaired and non-repaired DHs and their Lit ter-males (the control group) were delivered at 29 days' gestation by cesarean section. Some of the rabbits were killed and subjected to mea surements of body and lung weight, determination of the DNA and surfac tant (disaturated phosphatidylcholine; DSPC) contents of the lungs, an d Light and electron microscopic examination of the lung. Some newborn rabbits underwent endotracheal intubation and measurement of pressure -volume curves and pulmonary compliance. The total lung/body weight ra tios and total lung DNA contents in the repair group were greater than those in the non-repair Group (P < 0.01). There were no differences a mong the three groups in regard to body weight. When compared with the control group, both the repair and non-repair groups had increased DS PC content (P < 0.01 and P < 0.05, respectively), although there was n o difference between the repair and non-repair groups. Histologically, the thickness of the terminal air spaces was smaller and the size of the lung acini was larger in the repair group than the non-repair grou p. Electron-microscopically, the number of type II lung cells in both the repair and non-repair groups tended to be larger than that in the control group. When compared with the non-repair group, the repair gro up showed increased values for pressure-volume curves (P < 0.01) and p ulmonary compliance (P < 0.01). In conclusion. in utero repair of CDHs is effective in improving the hypoplasticity of tile lung accompanyin g this lesion.