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Background: In utero surgery was used to correct a surgically induced model of congenital diaphragmatic hernia (CDH) in premature and term lambs, resulting in an improvement in lung mechanics at birth., Methods: The differences between the in utero "patch" repair method and the "silo" repair method were assessed in 55 lambs by measuring the static respiratory system compliance (CST,RS) at birth in term (approximately 145 day) and in premature (128 day) animals., Results: Both methods resulted in similar improvements in CST,RS in term lambs, but in premature lambs only the silo method produced an increase in compliance. Comparisons of specific compliance related to length or birth weight did not alter these findings; however, corrections related to lung weight or a measure of lung volume showed there was no difference between any experimental groups in either term or premature lambs., Conclusions: These findings suggest that there was no difference in the intrinsic compliance of the lung tissue between normal, unrepaired and repaired animals, and that the differences in respiratory system compliance measured at birth may be due primarily to differences in lung size. The silo repair method appears to provide an earlier improvement in CST,RS than the patch repair method.

Nineteen survivors of congenital diaphragmatic hernia repair were compared with age and sex matched control children six to 11 years after repair. All subjects were examined clinically and underwent lung function testing. The patients also had individual lung volumes assessed radiographically and had radionuclide (krypton-81 m, technetium-99 m macroaggregates) ventilation-perfusion (V/Q) lung scans. Four patients had pectus excavatum and two had mild scoliosis. Spirometric measurements were lower in the patients than in the control subjects but only the differences in peak expiratory flow and flow at 50% of expired vital capacity were significant. The radiographic left lung volumes in patients surviving left diaphragmatic repair were larger than expected at 49.3% (SD 2%), suggesting alveolar overdistension. V/Q scans showed a mismatch in the ipsilateral lung, mean Q (40% (7%] being significantly lower than mean V (47% (6%)). In seven patients who had required ventilation for four days or more perfusion to the ipsilateral lung was significantly lower (34% (6%)) than values for the 12 patients ventilated for less than four days (43% (6%)). Survivors of right diaphragmatic repair had a better outcome in terms of relative radiographic lung volumes and V/Q distribution. More severely affected children are now surviving repair of congenital diaphragmatic herniation, with residual pulmonary abnormalities that could produce functional impairment in adult life.

Tests of the response to perfusion of the oesophagus were made in 54 patients divided into three groups. Group I consisted of patients with symptomatic hiatal hernia, group II hiatal hernia patients with peptic stricture, and group III normal individuals. Each individual oesophagus was perfused at a rate of 45-65 drops per minute over 25 minutes with six solutions: normal saline, N/10 HCl, taurine conjugates of bile salts in normal saline, taurine conjugates of bile salts in N/10 HCl, glycine conjugates of bile salts in normal saline, and taurine and glycine conjugates in a ratio of 1 to 2 in normal saline. It was found that acidified taurine solutions were more irritating than acid alone. With a 2mM/l solution of taurine in acid, symptoms are produced even in controls. With a 1 mM/l solution of the same conjugates, the majority of normal people feel slight heartburn or nothing, and therefore perfusion into the oesophagus of such a solution could be used as a test for oesophagitis.

Quantitative analysis has been used to assess growth in a lung from an infant aged 21/2 months in whom a diaphragmatic hernia was repaired at birth. The lungs had been abnormally small at birth but at 21/2 months were of normal volume. Alveoli had multiplied at the normal rate after birth but had not reached the number normal of age. The number per acinus was normal but the alveoli were increased in size, particularly in the left lung. The airway number, and thus alveolar, acinar, and arterial number, were all reduced in both lungs, the ipsilateral being most affected. The pulmonary blood vessels in both lungs showed an increased muscularity that did not correlate with lung volume or alveolar number, a feature that may have been present at birth. The degrees of hypoplasia in the two lungs were different at birth and this difference had been maintained. The effect of the disturbance to lung growth on the functioning of the lung is discussed.