Retrospective study of 111 cases of congenital diaphragmatic hernia treated with early high-frequency oscillatory ventilation and presurgical stabilization

Abstract

Background The prognosis of babies with congenital diaphragmatic hernia (CDH) remains unsatisfactory despite recent advances in medical and surgical treatment. Most authors agree that the best way to improve outcomes for this disease is to focus on pulmonary hypoplasia and persistent pulmonary hypertension (PPH), the 2 most unfavorable prognostic factors for patient survival. However, controversy remains regarding the best treatment of CDH. In the past decade, several institutions have developed treatment protocols that include high-frequency oscillatory ventilation (HFOV), preoperative stabilization, and no thoracic drain. This strategy is 1 of several “gentle ventilation” strategies. We describe our 10-year experience in treating a cohort of 111 infants with CDH managed with this “gentle ventilation” strategy. Methods From October 1994 to June 2005, 111 babies with CDH were treated at our institution with HFOV. Babies progressed to inhaled nitric oxide and extracorporeal membrane oxygenation if severe PPH persisted. After a period of preoperative stabilization, surgery was performed via an abdominal approach. In case of large defects or diaphragmatic agenesis, a prosthetic patch was used. No thoracic drain was left in place at the end of surgery. The charts of all babies were reviewed. General characteristics, respiratory management, as well as perioperative and postoperative data were analyzed and correlated with survival. Predicted and actual survival rates in high-, intermediate-, and low-risk groups were analyzed on the basis of the equation described by the Congenital Diaphragmatic Hernia Study Group in 2001. Results The overall survival rate in our group of patients with CDH was 69.4% regardless of side of the defect. Incidence of a prenatal diagnosis before the 25th gestational week, coexistence of severe congenital heart disease (overall incidence, 5.4%), or other major associated anomalies, as well as the presence of a diaphragmatic agenesis were significantly higher in nonsurvivors. Thirty-six had severe PPH, of which 26 (76.5% of nonsurviving patients) died. Survivors and nonsurvivors had significant differences in blood gas analysis and respiratory management data recorded before and after the diaphragmatic correction. Ninety-nine (89%) patients underwent correction of the diaphragmatic defect. A patch was used in 44 (44%) patients and 15 of them died (survivors, 37.7%; nonsurvivors, 68.2%; P = .0111). Six (43%) of 14 patients with a preoperative pneumothorax (survivors, 10.3%; nonsurvivors, 27.3%; P > .05) and 7 (58%) of 12 patients with a postoperative pneumothorax needing a thoracic drain (survivors, 6.5%; nonsurvivors, 31.8%; P = .0013) died. In all cases, pneumothorax was ipsilateral. Two patients required oxygen therapy at discharge. The predicted survival rate was 69%; there was no difference between predicted and actual overall survival as well as between predicted and actual survival in low-risk (predicted survival rate, >66%), intermediate-risk (predicted survival rate, 34%-66%), and high-risk (predicted survival rate, <33%) groups. Conclusions The CDH treatment strategy that includes HFOV, preoperative stabilization and no thoracic drain ensures survival with minimal pulmonary morbidity (low rate of pulmonary infections and low rate of patients requiring oxygen at home) in most affected babies. Persistent pulmonary hypertension has been the most challenging factor that ultimately determined the final outcome, and availability of new vasoactive drugs is mandatory to ameliorate the prognosis especially in high-risk patients. Meanwhile, survival comparisons of low-, intermediate-, and high-risk groups between institutions using different protocols will allow the identification of the best strategy for CDH management.