Objective-To determine whether corrodible materials may be safely used as biodegradable cardiovascular implants. Design-Corrodible iron stents (> 99.8% iron) were produced from pure iron and laser cut with a stent design similar to a commercially available permanent stent (PUVA-AS16). A total of 16 NOR-I stents were implanted into the native descending aorta of 16 New Zealand white rabbits (mean luminal diameter at the implantation site 3.4 mm, balloon diameter to vessel diameter ratio 1.13). Results-No thromboembolic complications and no adverse events occurred during the follow up of 6-18 months. All stents were patent at repeat angiography after 6 (n = 9), 12 (n = 5), and 18 months (n = 2) with no significant neointimal proliferation, no pronounced inflammatory response, and no systemic toxicity. Conclusions-This initial in vivo experience suggests that degradable iron stents can be safely implanted without significant obstruction of the stented vessel caused by inflammation, neointimal proliferation, or thrombotic events.

In patients with cyanotic congenital heart disease stenting of the arterial duct is an effective alternative to surgical aorto-pulmonary shunts.

No abstract

Objective-To investigate the specific sequelae of the Fontan operation, and particularly the potential sequelae of chronically elevated systemic venous pressure. Design-A retrospective analysis of clinical and haemodynamic data and evaluation of organ function in 80 surviving patients undergoing modified Fontan operation for various forms of underlying functionally univentricular hearts. Patients-65 patients (81%) who had undergone a total cavopulmonary anastomosis and 15 an atriopulmonary anastomosis. Follow up ranged from 12 to 106 months (mean 54 (SD 23) months). Results-62 patients underwent postoperative cardiac catheterisation (mean systemic venous pressure 10-5 (2.5) mm Hg and cardiac index 3-1 (0.7) 1lmin/m2). Older age at operation was significantly correlated with both higher systemic venous pressure and lower cardiac index. Atrial arrhythmia was documented on Holter electrocardiogram in 17%. Protein losing enteropathy (with abnormal a,-antitrypsin clearance) was found in 2/80 patients (2.5%). Ten patients had hypoproteinaemia, with a significantly higher incidence in patients after total cavopulmonary anastomosis and young age at operation. Liver function tests reflecting liver synthesis and metabolism were normal in all, whereas mild cholestasis was found in nearly 300/o-predominantly in patients with a cardiac index of < 3 I/min/m2 (P = 0 045). Five patients (6.2%) developed atrial thrombosis. Coagulation factor analysis in 44 patients showed protein C deficiency in 11 (25%); laboratory signs of activation of the coagulation system were found in four of these (9%). None of the abnormal laboratory indices was significantly related to underlying cardiac malformation, postoperative systemic venous pressure, or follow up interval.Conclusions-A high proportion of clinically asymptomatic patients had abnormal laboratory findings on mid-term follow up. Detailed evaluation of organ function is necessary to detect the need for further diagnostic procedures before clinical symptoms develop. (Heart 1997;78:154-159)

Objective-To report initial experiences with transcatheter occlusion of atrial septal defects using a new occlusion device.

Background-Complications

In this review, we describe the experience from 13 European centres using the CardioSEAL and Starflex double umbrella devices to close interatrial communications within the oval fossa (so-called 'secundum' defects). Between October 1996 and April 1999, the procedure was attempted in 334 patients with a mean age of 12 years and a mean weight of 44kg. The mean measured stretched diameter of the defect was 15 mm. In the overall group, the defect was solitary in 245 patients (73%), multiple in 21 (6%), associated with an aneurysm of the flap valve in 15 (5 %), was represented by patency of the oval foramen in 44 (13%), and was a fenestration in a Fontan repair in 9 (3%). In all patients, the devices were inserted under general anesthesia, using fluoroscopic and transesophageal echocardiographic control. Implantation was achieved in 325 (97,3%). The device embolized within either a few minutes or a few hours in 13 patients (4%). Of these, uncomplicated surgical repair was undertaken in 10, while the device was retrieved in 3 using catheters and a second device was successfully implanted. Residual shunting was detected immediately after the procedure in 41% of the patients, with the incidence decreasing to 31% at discharge, 24% at 1 month, 21% at 6 months, and 20.5% at one year. During the period of follow-up, elective surgical repair became necessary in two patients, due to malposition of the device in one, and late embolization in the other. Fractures of arms were seen in 6.1 %, most commonly with the largest devices. All those with fractured arms of the device were asymptomatic, and no clinical complications related to the fractures were observed. There were no arrhythmias, endocarditis, valvar distortion, thromboembolic events, or other complications. After one year of follow-up, clinical success, defined as complete closure of the defect or presence of only a trivial leak, had been obtained in 92.5% of the patients. We conclude, therefore, that these devices produce excellent results when used to close defects of small to moderate size. Results are less than optimal, or else complications ensure, when attempts are made to close very large defects.

The risk of late coronary artery lesions must be considered when catheter ablation at the RA wall is planned in children with free-wall accessory AV pathways.