Serial Dilation and Intentional Fracturing of Stents in Congenital Heart Disease-Benchside Tests and Initial Clinical Results.

Abstract

There is some reluctance to implant stents in small children due to concerns regarding outgrowing the maximal stent diameter during follow-up. Evaluation of a treatment strategy on the bench side, including intentional stent fracturing, and description of our initial clinical experience. A series of benchside tests was performed with small stents, in which the stents were dilated above the rated diameters until they ultimately fractured. The diameters and pressures needed to fracture these stents were documented. This approach of intentional stent fracturing was used to treat the first series of patients. Benchside testing of coronary stents (Coroflex blue, Onyx, and Bentley coronary) and the different-sized Cook Formula stents confirmed that all these can be fractured intentionally. An important step to prevent the development of a "napkin ring" was to implant a second larger stent before dilatation with ultra-high pressure balloons (fracturing procedure). In 17 patients, previously implanted stents were dilated serially and ultimately fractured. The stents had been implanted in branch pulmonary arteries (n = 9), in the right ventricular outflow tract (n = 3), and in the aortic isthmus (n = 5). After dilation up to the fracturing diameter known from the benchside tests, a second larger stent was implanted and the initial stent was fractured with ultra-high-pressure dilatation. Fracturing of the stent was possible in all patients. No serious complications were noted. Serial dilatation and intentional fracturing of stents are feasible, do not increase the risk for complications, and may play an important role in the management of growing children with congenital heart defects.