Postoperative comparison of chest closure with or without a drain following patent ductus arteriosus ligation: A non-blinded randomised controlled clinical trial

Abstract

Background: Patent ductus arteriosus is the commonest congenital cardiac lesion encountered at the cardiovascular surgical division of the Uganda Heart Institute, Mulago Hospital complex. It accounted for 54% (47/86) of all surgical operations done in 2010. Its definitive management is by device closure or ligation of the patent vessel necessitating a thoracotomy. Insertion of a chest drain post operatively to prevent fluid accumulation in the pleural space is the standard of care. This exposes the patients to complications such as; increased risk of infection, pain, persistent pleural space accumulations, poor lung excursions with low oxygen saturations (<92%), decreased mobility and prolonged hospital stay. Some retrospective studies have shown that there is no added risk to the patient if routine chest drainage is omitted following ligation of the patent ductus arteriosus. This has not been evaluated prospectively in low and middle income countries. Objective. To compare the post-operative outcomes of thoracotomy closure in patients with a drain and in those without a drain following patent ductus arteriosus ligation. Methods. A non- blinded randomized controlled clinical trial done at Mulago National Teaching Referral Hospital. Intervention. Surgical ligation of patent ductus arteriosus and thoracotomy closure without a chest tube. The control group received surgical ligation and thoracotomy closure with chest tube insitu. Patients were monitored hourly both clinically and by monitors for development of complications for 24 hours, and then followed up till discharge. Outcome of interest. The combined primary endpoint constituted the following complications; significant pleural space accumulation of fluid or air and oxygen saturations of < 92% or surgical site infection. Analysis. Outcomes in both arms were compared by intention to treat analysis using STATA version 11.2. Statistical significance was p=0.029 according to the fixed nominal rule suggested by Pocock, this being an interim analysis. Results. We recruited 44 patients with a confirmed diagnosis of patent ductus arteriosus and randomized 22 patients to each arm. For the combined primary outcome, the data show that more participants in the no-drain arm had significantly favorable outcomes (less adverse events) compared to the drain arm, (OR: 0.15, 95% CI: 0.04 – 0.61, p=0.008). After adjusting for potential confounders, this “protective” effect remained significant (OR: 0.13, 955 CI: 0.02 – 0.77, p=0.024). Conclusions: Avoiding routine use of a chest drain after uncomplicated PDA surgery is safe and effective and does not put the child at risk of retaining symptomatic pleural fluid. Children who routinely receive a chest drain are more likely to suffer complications as a result of the tube itself which included increased pain and drainage site infection. Our results suggest that avoiding routine use of the chest drain is safe and efficacious for younger children but may be protective in older children (above 72 months). We recommend a multicentre trial where more numbers of children above 72 months can be realized to make more solid recommendations for this age group.