Determinants of successful balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum.

OBJECTIVES: This study reviewed our experience with percutaneous balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum and defined the anatomic and hemodynamic characteristics of infants in whom this procedure is successful and provides definitive therapy. BACKGROUND: Unlike children with valvular pulmonary stenosis, the follow-up of infants with critical pulmonary stenosis undergoing percutaneous balloon valvotomy is limited. METHODS: Between December 1987 and August 1992, percutaneous balloon valvotomy was attempted in 12 infants with critical pulmonary stenosis (n = 10) or pulmonary atresia with intact ventricular septum (n = 2). Two outcome groups were identified: Group A patients are acyanotic, have mild residual pulmonary stenosis and have not required operation; Group B patients have required operation. RESULTS: Of the 12 infants, 11 had a successful balloon valvotomy procedure. Group A patients (n = 7) have a residual gradient of 22 +/- 18.7 mm Hg (mean +/- SD) at follow-up of 3.2 years (range 1.2 to 5.0). In Group B (n = 5), operation was required for inability to cross the pulmonary valve (n = 1) or persistent severe hypoxemia for > or = 2 weeks after valvotomy (n = 4). Significant differences (p < or = 0.01) between the two groups (Group A vs. Group B) were identified in pulmonary valve annulus (Z value) 8.1 mm (-1.1) versus 5.5 mm (-3.4); tricuspid valve annulus (Z value) 14.0 mm (0.8) versus 8.8 mm (-1.8); right ventricular volume 65 versus 29 ml/m2; and Lewis index 10.9 versus 8.9. CONCLUSIONS: Percutaneous balloon valvotomy is effective and likely to provide definitive therapy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum who have a tricuspid valve annulus > 11 mm, pulmonary valve annulus > or = 7 mm and right ventricular volume > 30 ml/m2.

Intermediate-term results of Phase I Food and Drug Administration Trials of buttoned device occlusion of secundum atrial septal defects.

OBJECTIVES: This study was conducted to evaluate the intermediate-term results of the multi-institutional U.S. trial of the buttoned device for transcatheter closure of atrial septal defects (ASDs). BACKGROUND: The trial was conducted in three centers (University of Arizona, University of Michigan and University of Wisconsin) under a Food and Drug Administration (FDA)-approved clinical trial with investigational device exemption. Only short-term follow-up is known. METHODS: All 46 patients who had successful implantation of the device were prospectively followed up. Patients were evaluated at 1, 6 and 12 months after device occlusion and yearly thereafter. RESULTS: This cohort was followed up from 51 to 68 months (mean 60.8, median 62). Patient ages ranged from 1 to 62 years (median 4); weights ranged from 10 to 105 kg (median 18); and stretched ASD sizes were 14 +/- 4 mm (left to right shunts) and 10 +/- 3 mm (right to left shunts). Of the 46 patients, 45 (98%) had effective occlusion of their ASD, and 34 (74%) had complete ASD closure. The incidence of residual shunts decreased from 65% (30 of 46 patients) at 1 month after device placement to 27% (12 of 45 patients) at last follow-up. All residual shunts were quantitated as trivial. Only two patients (4%) required reintervention for significant residual defects. There were no cases of endocarditis or thromboembolism in 224 patient-years of follow-up. CONCLUSIONS: In up to 5.5 years of follow-up, the buttoned device provided effective closure in 98% of patients in whom the device was successfully implanted. The incidence of residual shunts decreased during follow-up, and no instances of endocarditis or thromboembolism were observed.

Acute results of balloon angioplasty of native coarctation versus recurrent aortic obstruction are equivalent. Valvuloplasty and Angioplasty of Congenital Anomalies (VACA) Registry Investigators.

OBJECTIVES: This study sought to compare the immediate results and risk factors for suboptimal outcomes of percutaneous balloon angioplasty for native versus recurrent aortic obstruction. BACKGROUND: Some cardiology centers have been reluctant to adopt balloon angioplasty for treatment of native aortic coarctation, while advocating balloon angioplasty over an operation for treatment of postsurgical or recurrent aortic obstruction. METHODS: Acute results were analyzed from 970 procedures (422 native and 548 recurrent lesions) performed between 1982 and 1995 in 907 patients from 25 centers. An acute suboptimal outcome was defined as one or more of the following: residual systolic pressure gradient > or = 20 mm Hg, residual proximal to distal systolic pressure ration > or = 1.33 or a major complication (death, aortic transmural tear, stroke). RESULTS: Bal loon angioplasty significantly (p = 0.0001) increased lesion diameter fo r both native (mean [+/= SD] 128 +/= 94%) and recurrent aortic obstruction (97 +/= 87%), with a significantly greater increase in the native group (p = 0.0001). A reduction in systolic pressure gradients was significant in both groups (p = 0.0001), but slightly higher (p = 0.01) for native (-74 +/- 24%) versus recurrent obstruction (-70 +/- 31%). Death associated with angioplasty was reported in 0.7% of patients with native and in 0.7% of patients with recurrent lesions (p = 1.00). An acute suboptimal outcome was noted with angioplasty in 19% of native and in 25% of recurrent lesions (p = 0.04). Significant independent risk factors included higher preangioplasty systolic gradient (odds ratio [OR] 1.39/10-mm Hg increment; 95% confidence interval [CI] 1.28 to 1.50, p = 0.0001), earlier study date (OR 0.92/1-year increment, 95% CI 1.02 to 1.26, p = 0.02) and recurrent obstruction (OR 1.39 vs. native lesions, 95% CI 1.00 to 1.94, p = 0.05). CONCLUSIONS: Acute results and complications of balloon angioplasty of native coarctation appear to be equivalent or slightly superior to those of recurrent aortic obstructions.

Follow-up of coil occlusion of patent ductus arteriosus.

OBJECTIVE: We sought to determine the prevalence and fate of residual ductal shunting following coil occlusion of patent ductus arteriosus. BACKGROUND: Although transcatheter coil occlusion of patent ductus arteriosus has gained popularity, few follow-up data have been reported. METHODS: A review of 75 patients who underwent coil occlusion was performed. Residual shunting was investigated by Doppler echocardiography in follow-up. Angiograms were reviewed to obtain minimal ductal diameter and ductal angiographic type. RESULTS: Residual shunts were found in 31 patients (41%) on the day of the procedure, and of these, spontaneous closure was noted in 17 (55%) at 2 weeks to 20 months of follow-up. Of the 75 patients studied, 5 (7%) required a second coil procedure, and 10 (13%) remained with persistent residual shunts at most recent follow-up. Actuarial analysis estimated a 6 +/- 5% prevalence of residual shunts 20 months after a single coil procedure and 3 +/- 3% after all coil procedures. Minimal ductal diameter was associated with immediate complete ductal occlusion by a single coil. These patients had significantly smaller (p = 0.003) minimal ductal diameters (1.2 +/- 0.7 mm) than those who required two coils during their initial procedure to achieve immediate occlusion (1.9 +/- 0.7 mm), those who required a second coil procedure (2.0 +/- 0.9 mm), those who had spontaneous closure of residual shunts (1.9 +/- 0.7 mm) and those with persistent residual shunts (2.0 +/- 0.9 mm). No association was identified between ductal angiographic type and outcome of coil occlusion. No late adverse clinical events of coil occlusion or evidence of recanalization was found. CONCLUSIONS: Small residual shunts are common after coil embolization of patent ductus arteriosus, but most close spontaneously. Actuarial analysis estimates complete closure in 94% at 20 months, and reintervention was required in only 7% of patients.

Inducibility of intra-atrial reentrant tachycardia after the first two stages of the Fontan sequence.

OBJECTIVES: We sought to examine the incidence and possible factors for inducible intra-atrial reentrant tachycardia (IART) in a group of patients after two stages of the Fontan sequence but before the operation. BACKGROUND: Intra-atrial reentrant tachycardia occurs in 10% to 40% of patients after the Fontan operation. No data are available regarding the potential for IART after the first two stages of the Fontan sequence but before the operation. METHODS: The IART induction protocol included programmed extrastimulation and rapid atrial pacing, with and without isoproterenol. RESULTS: The median age of the study group (n = 44, 27 males) was 1.7 years (range 1.2 to 5.2). Forty patients were in sinus rhythm. Twelve patients (27%) had inducible, sustained (>1 min) IART. Three patients (8%) had inducible, nonsustained IART. Bivariate analysis revealed that patients with sustained IART were significantly older at their second operation (median 0.54 vs. 0.40 years, p = 0.05). Multivariate logistic modeling revealed that older age (> or =0.55 years) at the second palliative operation (p = 0.04), older age (> or =1.95 years) at evaluation before the Fontan sequence (p = 0.04) and female gender (p = 0.03) were independently associated with sustained IART. A trend toward a greater frequency of sustained IART was seen in those patients with moderate or severe atrioventricular valve regurgitation (p = 0.07) and in those with resection of the atrial septum (p = 0.06). CONCLUSIONS: The rate of inducible, sustained IART in a group of patients before the Fontan operation is 27% and is associated with older age at the time of second-stage palliation, older age at pre-Fontan evaluation and female gender.

Results of transvenous occlusion of secundum atrial septal defects with the fourth generation buttoned device: comparison with first, second and third generation devices. International Buttoned Device Trial Group.

OBJECTIVES: The purpose of this study was to assess safety and effectiveness of the fourth generation buttoned device in dosing atrial septal defects (ASDs) and to test the hypothesis that introduction of double button reduces unbuttoning rate without reducing effectiveness. BACKGROUND: Because of the high unbuttoning rate (7.2%) with first, second and third generation buttoned devices, the device was modified (fourth generation) so that there were two radiopaque spring buttons 4 mm apart on the button loop attached to the occluder. METHODS: During a four-year period ending in September 1997, 423 patients, ages 1.5 to 80 years (median 16 years), underwent closure of ASD at 40 medical centers around the world. RESULTS: The ASD size varied between 5 and 30 mm (median 17 mm). The device size varied between 25 and 60 mm. Unbuttoning occurred in 4 (0.9%) of 423 patients. Effective occlusion, defined as no (n = 343) or trivial (n = 34) residual shunt on echo-Doppler studies performed within 24 h of the procedure, was demonstrated in 377 patients (90%). Thus, the unbuttoning rate (0.9 vs. 7.2%) decreased (p<0.01) while effective occlusion rate (90 vs. 92%) remained unchanged (p>0.1) with this device, compared with earlier generation devices. During follow-up from one month to five years (23+/-15 months), 21 (5%) of 417 patients required surgical (n = 12) or transcatheter (n = 9) reintervention, mostly to treat significant residual shunt. In the remaining patients there was gradual reduction and disappearance of the residual shunt. No wire integrity problems were observed. CONCLUSIONS: These data suggest that the fourth generation buttoned device is as effective as earlier generation devices, but without significant unbuttoning. Follow-up results remained good, with a reintervention-free rate of 89% at five years.

Accuracy of central venous pressure measurement from the abdominal inferior vena cava.

Central venous pressure measurements in the abdominal inferior vena cava were compared with measurements in the right atrium in 10 infants and 10 children during cardiac catheterization. At end expiration, the mean pressures at these two sites were within 1 mm Hg of each other in all 20 patients, with a mean difference of 0.0 +/- 0.36 mm Hg. The abdominal inferior vena cava is a safe and convenient site for measurement of central venous pressure, and our study confirms that such measurements are accurate.

Usefulness of repeat balloon aortic valvuloplasty in children.

This retrospective study examines all 15 patients who underwent a second balloon dilation procedure for congenital aortic stenosis to determine its safety and efficacy. The recurrent gradient was significantly reduced, but 4 patients had unsatisfactory gradient relief, 3 of whom had previous surgical valvotomies; therefore, we conclude that repeat balloon aortic valvuloplasty is worthwhile, although third balloon dilations may not be beneficial.

Comparison of simultaneous Doppler- and catheter-derived right ventricular dP/dt in hypoplastic left heart syndrome.

Doppler estimation of RV dP/dt correlates well with micromanometer catheter-measured values in children with hypoplastic left heart syndrome. Doppler estimation of RV dP/dt is a method of quantifying RV systolic function independent of geometric assumptions, and may be a valuable method for longitudinal analysis of RV function.

Comparison of hospital charges for closure of patent ductus arteriosus by surgery and by transcatheter coil occlusion.

Hospital charges for coil occlusion were significantly less than for surgical closure of patent ductus arteriosus, and were reduced over time as experience permitted refinement of the coil occlusion protocol. The expected hospital charges for closure by a coil occlusion strategy, including the charges for surgical closure in patients with failed coil occlusion, was less than the hospital charges for surgical closure strategy under any reasonable estimate of coil occlusion efficacy.

Atrial septal defect occlusion with the buttoned device (a multi-institutional U.S. trial).

A clinical trial was conducted of the buttoned device for transcatheter closure of ostium secundum atrial septal defect. Occlusion was attempted in 57 patients aged 1 to 62 years (median 5). The procedure was abandoned in 7 patients after 1 or more unsuccessful attempts, and devices were released in 50 patients. Urgent surgical retrieval was necessary in 4 patients because of unstable device position: 3 devices "unbuttoned," with migration of the counteroccluder to the pulmonary artery or inferior vena cava, and 1 intact device embolized to the main pulmonary artery. All patients remained stable and underwent successful operation. Successful device implantation was therefore achieved in 46 patients, with immediate reduction in Qp/Qs from 1.8 +/- 0.6 to 1.1 +/- 0.2 (mean +/- SD, p < 0.0001). At most recent follow-up (1 to 20 months), 45 of 46 patients (98%) have no shunt or a trivial residual shunt. The prevalence of residual shunts declined from 65% at 1 month to 19% at 12 months after the occlusion procedure (p < 0.0001). Complications included unbuttoning of a fourth device, transient tricuspid regurgitation in 2 patients, and transient mitral regurgitation in 2 patients. An episode of asymptomatic atrial flutter was noted in a 46-year-old patient which may have been related to device implantation, but which has not recurred. There have been no cases of endocarditis or thromboembolism in 350 patient-months of follow-up. The buttoned device provided effective closure of the atrial septal defect in 45 of 57 patients (79%) in whom implantation was attempted and in 45 of 46 patients (98%) in whom device implantation was successfully accomplished.(ABSTRACT TRUNCATED AT 250 WORDS)

Late follow-up of balloon angioplasty in children with a native coarctation of the aorta.

Between May 1984 and April 1993, 59 children underwent balloon angioplasty of a native coarctation at our institution. The follow-up protocol included a cardiac catheterization 1 to 2 years after angioplasty, which was performed in 90% of patients with > or = 2 years follow-up. Angioplasty caused an acute decrease in peak systolic gradient from 46 +/- 2 to 15 +/- 2 mm Hg, without early aneurysm or emergent surgical intervention in any patient. Based on follow-up data, a satisfactory result was obtained in 38 patients (64%; 70% confidence limit: 58% to 71%), defined as a residual systolic gradient < 20 mm Hg and no aneurysm. In these patients the gradient decreased acutely from 43 +/- 2 to 9 +/- 1 mm Hg, was 6 +/- 1 mm Hg at follow-up catheterization, and 9 +/- 2 mm Hg by clinical evaluation 4.4 +/- 0.3 years after angioplasty. Twenty-one patients (36%; 70% confidence limit: 29% to 42%) had an unsatisfactory result due to a residual gradient > or = 20 mm Hg (n = 19) or aneurysm formation (n = 3), or both. Restenosis occurred in 6 patients, and occurred more in infants than in children > or = 12 months of age (3 of 5 infants vs 3 of 41 children, p = 0.01). Thus, balloon angioplasty provides an effective initial treatment strategy for native coarctation in most children aged > 12 months.

Comparison of hospital charges for balloon angioplasty and surgical repair in children with native coarctation of the aorta.

A retrospective review of hospital charges was performed in children > 1 year old with native coarctation of the aorta who underwent balloon angioplasty, primary surgical repair, or elective surgical repair after unsuccessful balloon angioplasty. Hospital charges were less overall in the balloon angioplasty group, although the failure rate was higher.

Management of complications of Sideris transcatheter devices for atrial septal defect closure.

Various devices that can be inserted transvenously to close an ostium secundum atrial septal defect are undergoing clinical trials. Although these are safe and effective in most instances, they may occasionally dislodge or fail to "button" properly, causing migration and embolization. We report two cases in which the occluder and counteroccluder of the Sideris device for transvenous atrial septal defect occlusion (Custom Medical Devices, Amarillo, Tex.) failed to "button" appropriately, migrating in the right atrium in one patient and embolizing to the pulmonary artery in the second patient. An emergency operation was required to retrieve the device and repair the atrial septal defect.

Central pulmonary artery growth patterns after the bidirectional Glenn procedure.

The changes in pulmonary artery size and hemodynamics in 30 patients with univentricular cardiac anatomy were examined before and after bidirectional Glenn procedures done between October 1989 and February 1992. Serial angiographic and hemodynamic examinations before and 17.6 +/- 1.6 months after bidirectional Glenn procedures were compared. At the follow-up study there was no significant change in diameter of the pulmonary artery ipsilateral to the bidirectional Glenn shunt, however, a significant decrease was noted in the diameter of the pulmonary artery contralateral to the bidirectional Glenn shunt (p = 0.04). There was also a 32% decrease in the Nakata index of total cross-sectional pulmonary artery area after the bidirectional Glenn procedure (p = 0.004). Total pulmonary blood flow and mean pulmonary artery pressure had decreased, and arterial oxygen saturation had increased at follow-up. These changes, however, did not correlate with the observed changes in pulmonary artery size. By linear regression analysis, a significant relationship was identified between the Nakata index before the bidirectional Glenn procedure and the absolute change in Nakata index (r = 0.83). A significant decrease in Nakata index occurred only in patients with a bidirectional Glenn shunt in place more than 15 months. Sixteen of the 30 patients subsequently underwent total cavo-pulmonary anastomosis with 7 requiring concurrent surgical pulmonary artery reconstruction. Changes in pulmonary artery size observed more than 15 months after the bidirectional Glenn procedure may have implications for subsequent Fontan repair in children with univentricular anatomy.

The management of tetralogy of Fallot with pulmonary atresia and diminutive pulmonary arteries.

Since September 1991, 14 consecutive patients with tetralogy of Fallot, pulmonary atresia, and diminutive pulmonary arteries have undergone staged repair. All patients had multiple aortopulmonary collateral arteries and the ductus arteriosus was absent in 11. Mean sizes of the right and left pulmonary arteries were 2.2 +/- 0.7 mm and 1.9 +/- 0.8 mm, respectively (range 0.5 to 3.0 mm). Eight patients (57%) have subsequently received complete repair. Age at initial procedure (shunt, right ventricle-pulmonary artery conduit, or direct aorta-pulmonary artery anastomosis) in this group was 5.3 +/- 6.8 months. The number of operative procedures to achieve complete repair was 2.9 +/- 0.8 per patient (range 2 to 4). Intraoperative postrepair peak right ventricle-left ventricle pressure ratio was 0.57 +/- 0.17. Six of 8 patients (75%) required additional interventional procedures (mean 1.5 +/- 1.2 per patient) for angioplasty of peripheral pulmonary artery stenoses, coil embolization of aortopulmonary collateral arteries, or intra-operative insertion of intravascular pulmonary artery stents. Mean follow-up from complete repair was 8.7 +/- 8.3 months (range 0.5 to 23.8 months) and is complete. There was one in-hospital death at 45 days, and one late cardiac death at 20.3 months. Six patients had initial palliative operations (unifocalization, right ventricle-pulmonary artery conduit, direct aorta-pulmonary artery anastomosis, or transannular outflow patch) but have not undergone complete repair. Age at initial procedure in this group was 27.9 +/- 56.9 months (range 0.27 to 155 months), and mean follow-up from initial procedure was 10.9 +/- 11.2 months (range 0 to 31.4 months). The operative mortality rate was 33% (2 of 6 patients). There was one late noncardiac death at 5.3 months. Three patients are awaiting further intervention or repair. This experience suggests that complete repair is feasible even in patients with extremely diminutive pulmonary arteries (< or = 3.0 mm). Pulmonary artery growth is facilitated by early (3 to 6 month) establishment of central pulmonary artery flow by right ventricle-pulmonary artery conduit (pulmonary arteries > 1.5 mm) or by direct ascending aorta-pulmonary artery anastomosis (pulmonary arteries < 1.5 mm). Subsequent interventional catheterization and operative procedures as required for pulmonary artery stenoses and coil embolization of collateral arteries allow continued recruitment of central pulmonary arteries and may obviate or minimize the need for unifocalization procedures.

Transcatheter stenting of the ductus arteriosus: evaluation as an alternative to surgical shunts.

Implantation of 3.5 mm Gianturco-Roubin coronary artery stents into the ductus arteriosus was evaluated as an alternative to surgical systemic to pulmonary arterial shunts in 3 weanling piglets. Thrombosis of the ductus occurred in all 3 animals (95% confidence limits 29-100%) within 1 hour, despite pretreatment with heparin. In each case, thrombus filled the ductus arteriosus but did not extend to any extraductal portion of the stents. Rapid, heparin-resistant thrombus formation precludes use of this stent procedure as an alternative to surgical shunts.