Difficulties generated by the small, persistently patent, arterial duct

Over recent years, echo-Doppler cardiography has shown that a small, sometimes silent, arterial duct exists in more patients than previously recognized. To know the incidence of an arterial duct subsequent to therapy, we studied retrospectively our patients undergoing open-heart surgery and surgical or catheter closure. Three groups of patients were studied: those with patency of the duct subsequent to open heart surgery without any sign of patency before or during surgery, those with persistent duct after surgical ligation and those with persistent patency after attempted catheter occlusion with the Rashkind device. In the first group (of 431 children) four (0.9%) had persistence of this duct, of which three were silent. In the second group, patency persisted in four of 100 patients (4%), three being silent. In the last group there were five persisting shunts, three producing no murmur, in 30 patients (17%). We compared our results with those reported in the literature and conclude that echo-Doppler cardiography is needed to detect persistent shunting across a duct after therapy, since most of the residual ducts in this study were silent. This means that clinical findings alone cannot be relied upon, and careful echo-Doppler cardiography is essential. Also, the process of closure of a persistent duct by surgical ligation or transcatheter intervention is no guarantee of success. The risk of infective endocarditis is important in such persistent ducts and, at present, it is unknown either for a small, silent duct or in a persistent duct that remains open after attempted transcatheter closure, but now is in association with a foreign body.