ABSTRACT
A 4-year-old girl with post-surgical complete atrioventricular block received an epicardial dual chamber pacemaker system. During further growth intermittent exit block occurred, first misinterpreted as neurological seizures. The epicardial lead was replaced using a transvenous approach, and a pacemaker with an integrated home monitoring facility was implanted. After her discharge, a rise in the pacing threshold automatically initiated an event message. On the basis of this information, the patient was called in and imminent dislodgement of the ventricular lead was diagnosed by x-ray. The lead was repositioned and was found stable over 1-year follow-up.
Subject(s)
Electrocardiography, Ambulatory , Heart Block/physiopathology , Heart Block/therapy , Home Care Services, Hospital-Based , Pacemaker, Artificial , Child, Preschool , Electrodes, Implanted , Equipment Failure , Female , HumansABSTRACT
OBJECTIVE: To test in a neonatal animal model the feasibility and biocompatibility of a new breakable stent that can be broken open by balloon dilatation during reintervention for use in neonates and infants. MATERIALS AND METHODS: Medical grade stainless steel breakable stents (n = 16) were interventionally implanted in systemic arteries in neonatal piglets (n = 7). Patency of the stented segments was shown by repeated angiography. Stents were redilated up to three times. After a follow up of 18-165 days the animals were killed and the tissue block containing the stent was excised. Besides standard histological examination, scanning electron microscopy was used for biocompatibility screening. RESULTS: The stents were broken by redilatation with a conventional angioplasty balloon catheter. During follow up, patency of all stented segments was shown angiographically. One stent became dislocated during implantation. One vessel ruptured during redilatation when an inadequately large balloon catheter was used for dilatation. No other complications were observed. Scanning electron microscopy showed complete cellular coverage of the stent struts. Histological examination showed thinning of the vessel wall and partial rupture of the media at the site of stent breakage. An only mild inflammatory reaction was detected. CONCLUSION: The new breakable stent can be broken open by simple angioplasty. Feasibility, effectiveness, and biocompatibility were shown in an animal model. Surgery to remove stents from paediatric patients due to disproportion between a previously implanted stent and the growing vessel may be avoided by the use of a breakable stent.
Subject(s)
Blood Vessel Prosthesis/standards , Stents/standards , Animals , Animals, Newborn , Biocompatible Materials , Blood Vessel Prosthesis Implantation/methods , Feasibility Studies , Femoral Artery , Prosthesis Design , Reoperation , SwineSubject(s)
Aorta, Thoracic/abnormalities , Fetal Diseases/diagnostic imaging , Subclavian Artery/abnormalities , Ultrasonography, Prenatal/methods , Aorta, Thoracic/diagnostic imaging , Female , Humans , Imaging, Three-Dimensional/methods , Infant, Newborn , Pregnancy , Subclavian Artery/diagnostic imaging , Ultrasonography, Doppler/methodsABSTRACT
OBJECTIVE: To evaluate the reasons for repeat intervention in patients treated with balloon expandable stents for pulmonary artery stenoses, with particular analysis of the time intervals between interventions. DESIGN: A retrospective observational study. SETTING: A single paediatric cardiology centre. PATIENTS: 38 patients, mean age 6.9 years, range 6 days to 34 years (one adult patient); mean weight 19.7 kg, range 2.5-75 kg. INTERVENTION: Implantation of balloon expandable stents in 46 cases of main pulmonary artery stenosis, right pulmonary artery stenosis, left pulmonary artery stenosis, or right ventricle to pulmonary artery conduits. MAIN OUTCOME MEASURES: Adaptation of stent diameter to patient growth; development of pulmonary arteries; pressure gradient in the right ventricle. RESULTS: 56 stents were implanted in 46 lesions. During a mean follow up time of 2.2 years, 40 repeat dilatations were performed on 28 of 42 reinvestigated stents. A second repeat dilatation was performed on eight stents, and a third on four stents. The mean time period between implantation and repeat dilatations was 15.5 months. CONCLUSIONS: Repeat dilatation of stented pulmonary arteries was done mainly to adapt the stent diameter to the patient's growth. However, repeat dilatations were also performed to relieve stent obstruction caused by intimal proliferation (17.5%), or to overcome progressive external compression (25%). While most repeat interventions in adult patients are for intimal hyperplasia, in paediatric patients they are needed for a variety of reasons.
