Frank F. Ing

Intravascular Stents in Congenital Heart Disease: Short- and Long-Term Results From a Large Single-Center Experience☆☆☆

OBJECTIVES This report describes the results of the Food and Drug Administrations phase 1 and 2 clinical trials of intravascular stents at Texas Childrens Hospital. BACKGROUND Since the late 1980s, intravascular stent implantation for the treatment of arterial and venous stenoses in congenital heart disease has been highly successful. METHODS Stents were placed in postoperative pulmonary artery (PA) stenoses, congenital PA stenoses or stenoses of systemic veins/venous anastomoses. Prospective collection of data according to protocol was done before intervention, after stent implantation and at follow-up catheterization. RESULTS At stent implantation, pressure gradients decreased significantly in all three groups (mean +/- SD): from 46 +/- 25 to 10 +/- 13 mm Hg in postoperative PA stenoses (p < 0.001); from 71 +/- 45 to 15 +/- 21 mm Hg in congenital PA stenoses (p < 0.001); and from 7 +/- 6 to 1 +/- 2 mm Hg in stenoses of systemic veins/venous anastomoses stenoses (p < 0.001). Vessel diameters markedly increased: from 6 +/- 3 to 12 +/- 3 mm in postoperative PA stenoses (p < 0.001); from 3 + 1 to 9 + 1 mm in congenital PA stenoses (p < 0.001); and from 3 +/- 4 to 12 +/- 4 mm in stenoses of systemic veins/venous anastomoses (p < 0.001). In the postoperative and congenital PA stenoses groups, right ventricular pressure decreased (right ventricular pressure indexed to femoral artery pressure ratio): from 0.63 +/- 0.2 to 0.41 +/- 0.02 (p < 0.001) and from 0.71 +/- 0.3 to 0.55 +/- 0.35 (p = 0.04), respectively. Perfusion to a single affected lung increased from 31 +/- 17% to 46 +/- 14% (p < 0.001). On recatheterization (mean 14 months), results varied minimally. Repeat angioplasty of residual stent stenoses was safe and effective. Complications included four early patients with stent migration, three with stent thrombosis and two deaths. There were no late complications. Significant restenosis occurred in only three patients. CONCLUSIONS Intravascular stents for the treatment of vascular stenoses in congenital heart disease provide excellent immediate and long-term results.

Repeat Dilation of Intravascular Stents in Congenital Heart Defects

BACKGROUND Intravascular (Palmaz) stents have been successfully implanted in patients with congenital and acquired branch pulmonary stenosis. Early results are excellent; however, there is no information on restenosis and repeat dilation in patients with congenital heart disease. The purpose of this study is to review the incidence of restenosis and demonstrate the safety and efficacy of repeat dilation of stents in this group of patients. METHODS AND RESULTS Of 94 patients with 163 implanted stents in this single-center study, 43 patients with 73 implanted stents underwent recatheterization. Only 2 of 73 restudied stents (3%) developed significant restenosis. In 20 patients, 30 stents were redilated. At stent implantation, the mean age of this subgroup was 14.2 years, the mean intraluminal diameter increased from 4.9 to 10.7 mm (P = .0001), and the systolic gradient (mean) across the stent decreased from 52 to 11 mm Hg (P = .0001). At recatheterization (mean, 13 months), all stents were patent. The mean diameter decreased by 1.2 mm (P = .0001), but the increase in the gradient (mean, 3 mm Hg) was not significant (P = .11). After repeat dilation, the diameter increased from 9.5 to 12.2 mm (P = .0001), and the gradient decreased from 14 to 8 mm Hg (P = .0003). The 2 stents with restenosis were redilated successfully. Two patients underwent a successful second redilation of 3 stents at 18 and 26 months. There were no complications. CONCLUSIONS All stents remained patent. The occurrence of significant restenosis is low (3%), and these restenoses can be redilated and/or restented. Repeat dilation of the Palmaz stent implanted in branch pulmonary artery stenosis can be performed with safety and efficacy (94% success rate) up to 3 years after stent implantation.

Transcatheter Patent Ductus Arteriosus Closure in an Infant Using the Gianturco-Grifka Vascular Occlusion Device

A 2-month-old child with Down syndrome and a large patent ductus arteriosus underwent transcatheter closure using a new Food and Drug Administration-approved occlusion device. This device is described, along with its usefulness for other vascular defects.

Pulmonary artery stents: Long-term follow-up†

Objectives: Determine the long‐term outcomes of branch pulmonary artery (PA) stents. Background: PA stents in congenital heart disease effectively relieve stenoses in the short‐term. Published long‐term data are limited. Methods: Patients enrolled in an FDA IDE protocol from 1989–92 were included. Clinical follow‐up and catheterization data were evaluated. Patients were included if >5 year follow‐up data was available or if mortality occurred following the initial procedure. Results: There were five deaths: four due to progression of their underlying heart disease, and one from a complication during a follow‐up catheterization. Clinical data for 43 surviving patients demonstrated 39 patients (91%) are in NYHA class I or II. Seven patients underwent surgical intervention during the follow‐up period (five RV‐PA conduit, two Fontan revisions), but none addressed PA stenosis. Final repeat catheterizations were performed in 36 patients (55 stents) 7.2 ± 4.3 years post stent insertion with 1.2 ± 0.9 further procedures with stent dilations. In this subgroup, the minimum vessel diameter increased from 4.7 ± 1.8 to 13.4 ± 2.4 mm (P < 0.001), and the pressure gradient improved from 41 ± 25 to 9 ± 11 mm Hg (P < 0.001). Higher initial gradient and smaller balloons were associated with a final stent diameter of <14 mm (P = 0.030 and 0.046). Jailed vessels occurred in 49% of stents with abnormal angiographic flow in 18/55. Six repeat catheterizations resulted in complications, including the one procedural death. Conclusion: Stents implants for PA stenoses provide effective improvement in vessel caliber in the long‐term. Although repeat interventions are necessary, this procedure reduces RV pressure and provides an important alternative to surgery for residual PA obstruction.

The snare-assisted technique for transcatheter coil occlusion of moderate to large patent ductus arteriosus: immediate and intermediate results

OBJECTIVES The purpose of this study was to evaluate the feasibility, safety and efficacy of using a snare-assisted technique to coil occlude the moderate to large size patent ductus arteriosus (PDA). BACKGROUND Transcatheter occlusion of small PDAs using Gianturco coils is safe and effective. However, in larger size PDAs and/or those with short PDA length, the procedure still carries risks of coil embolization, incomplete occlusion and failure to implant the coil. METHODS From January 1994 to June 1997, the records of 104 consecutive snare-assisted coil occlusions of moderate to large PDAs (minimum diameter >2.0 mm) were reviewed. Immediate and intermediate outcomes including complete and partial occlusion, failure to implant and complications were analyzed with respect to ductal type and size. RESULTS Patient age ranged from 0.1 to 70.1 years (median 3.3 years). Minimum PDA diameter ranged from 2.1 to 6.8 mm (mean 3.0 +/- 0.9 mm). Angiographic types were A-62, B-13, C-6, D-14 and E-9. Using the snare-assisted technique, coil placement was successful in 104/104 patients (100%), irrespective of size or angiographic type. Immediate complete closure was observed in 73/104 (70.2%) and was related to smaller PDA size, but not to angiographic type. Complete closure was documented in 102/104 (98.1%) at 2- to 16-month follow-up. Successful closure was unrelated to PDA size or type. Coil embolization to the pulmonary artery occurred in 3/104 (2.9%) patients and was not related to PDA size or type. The need for multiple coils was found in 28/104 patients (26.9%), and was related to larger PDA size, but not to angiographic type. CONCLUSIONS The snare-assisted delivery technique allows successful occlusion of moderate to large PDAs up to 6.8 mm, irrespective of angiographic type. This technique permits improved control and accuracy of coil placement, and facilitates delivery of multiple coils.

The IMPACT Registry™: IMproving Pediatric and Adult Congenital Treatments

Tremendous advances have occurred in catheter-based interventions for congenital heart disease. Multicenter trials of these advances are either out of date or have been limited in scope. As such little is known on the application of these techniques in the current era. The IMPACT Registry (IMproving Pediatric and Adult Congenital Treatments) will allow us to measure variability in the performance and outcomes of both diagnostic and interventional cardiac catheterization procedures in all children and adults with congenital heart disease. The IMPACT Registry will be harmonized with the Society of Thoracic Surgeons Congenital Heart Disease Database, thereby allowing us to compare catheter-based interventions with surgical interventions when appropriate. The initial release of the registry will only include hospital-based outcomes, but ultimately it will transition to a longitudinal registry. The IMPACT Registry will provide the necessary benchmark tools for quality improvement activities for cardiac catheterization procedures in congenital heart disease.

Refinements in the implantation of pulmonary arterial stents: impact on morbidity and mortality of the procedure over the last two decades.

INTRODUCTION There is limited data on medium to long-term outcome, and the morbidity and mortality associated with the implantation, of pulmonary arterial stents. PURPOSE To assess changes in morbidity and mortality over the last two decades. METHODS Retrospective analysis of all patients stented between September, 1989 and July, 2001. RESULTS We implanted 664 Palmaz stents in 338 patients. The overall number included 229 patients who had undergone repair of tetralogy of Fallot, in whom 468 stents were implanted, 61 patients with congenital stenosis of the branches of the pulmonary trunk, in whom we placed 115 stents, 16 patients after an arterial switch operation who had 38 stents, and 32 patients after the Fontan operation who had 43 stents implanted. The mean age was 12.2 years, and the mean weight was 38 kg. The mean systolic pressure gradient decreased from 41 to 8.7 mmHg, the mean diameter of the stented vessel increased from 5.4 to 11.2 mm, and the ratio of right ventricular to femoral arterial pressure decreased from 0.66 to 0.45, each of these being significant at the level of p being less than 0.01. At a mean follow-up of 5.6 years, the mean gradient was 20 mmHg, the mean ratio of pressure between right ventricle and femoral artery was 0.5, and mean luminal diameter was 9.3 mm. Complications included migration of the stent in 8 patients, and pulmonary edema, hemoptysis and death in 5 patients each. There has been no mortality or morbidity since July of 1997. Technical changes include conservative serial dilations in congenital pulmonary arterial stenosis, avoidance of over-dilation, and simultaneous implantation of stents in the right and left pulmonary arteries in those with systemic pulmonary arterial pressure. Technological advances included shorter stents, improved balloon profiles, and central inflation of the stents. CONCLUSIONS Modification of stenting practices, and increased experience of the operators over the last two decades, has virtually abolished any morbidity or mortality associated with the implantation of stents for congenital or postoperative pulmonary arterial stenoses.

Twenty-Five Year Experience With Balloon Aortic Valvuloplasty for Congenital Aortic Stenosis

Balloon aortic valvuloplasty (BAV) is the primary therapy for congenital aortic stenosis (AS). Few reports describe long-term outcomes. In this study, a retrospective single-institution review was performed of patients who underwent BAV for congenital AS. The following end points were evaluated: moderate or severe aortic insufficiency (AI) by echocardiography, aortic valve replacement, repeat BAV, surgical aortic valvotomy, and transplantation or death. From 1985 to 2009, 272 patients who underwent BAV at ages 1 day to 30.5 years were followed for 5.8 ± 6.7 years. Transplantation or death occurred in 24 patients (9%) and was associated with depressed baseline left ventricular shortening fraction (LVSF) (p = 0.04). Aortic valve replacement occurred in 42 patients (15%) at a median of 3.5 years (interquartile range 75 days to 5.9 years) after BAV and was associated with post-BAV gradient ≥25 mm Hg (p = 0.02), the presence of post-BAV AI (p = 0.03), and below-average baseline LVSF (p = 0.04). AI was found in 83 patients (31%) at a median of 4.8 years (interquartile range 1.4 to 8.7) and was inversely related to post-BAV gradient ≥25 mm Hg (p <0.04). AI was associated with depressed baseline LVSF (p = 0.02). Repeat valvuloplasty (balloon or surgical) occurred in 37 patients (15%) at a median of 0.51 years (interquartile range 0.10 to 5.15) and was associated with neonatal BAV (p <0.01), post-BAV gradient ≥25 mm Hg (p = 0.03), and depressed baseline LVSF (p = 0.05). In conclusion, BAV confers long-term benefits to most patients with congenital AS. Neonates, patients with post-BAV gradients ≥25 mm Hg, and patients with lower baseline LVSF experienced worse outcomes.

Transseptal technique through atrial baffles for 3-dimensional mapping and ablation of atrial tachycardia in patients with d-transposition of the great arteries.

Access to targets for radiofrequency ablation in patients with congenital heart disease may be limited by anatomy and by surgically placed obstacles. In patients with atrial switch anatomy for d-transposition of the great arteries, the critical isthmus for maintenance of intraatrial macroreentry circuits is found often on the pulmonary venous side of the atrial baffle. A retrograde approach is extremely difficult for these arrhythmias. Use of transseptal techniques for diagnostic catheterization in these patients has been reported. We report the use of a transseptal technique in two cases in conjunction with 3-dimensional electroanatomic mapping for the successful ablation of atrial reentry tachycardias in patients with Mustard and Senning anatomy.

Outcomes of transcatheter occlusion of patent ductus arteriosus in infants weighing ≤ 6 kg.

OBJECTIVES We sought to analyze the outcomes of transcatheter patent ductus arteriosus (PDA) occlusion using a variety of devices in infants weighing ≤6 kg. BACKGROUND Indications for transcatheter closure of a PDA in infancy include congestive heart failure and/or failure to thrive. Devices available for small infants may be problematic for various reasons, including sheath size, stiffness of delivery system, and anchoring and retrievability characteristics of the device. The Amplatzer Ductal Occluder is approved by U.S. Food and Drug Administration for children weighing >6 kg and older than 6 months of age. METHODS We performed a multicenter, retrospective analysis of children weighing ≤6 kg in whom transcatheter PDA occlusion was attempted between January 1995 and November 2005 at Texas Childrens Hospital and January 2001 to November 2005 at Childrens Hospital of San Diego. RESULTS A total of 62 patients underwent attempted closure. The mean age at catheterization was 4.7 ± 2.8 months with a mean weight at catheterization of 4.6 ± 0.9 kg. Successful device placement was achieved in 58 of 62 patients (94%). Among those receiving a device, complete occlusion was noted in all 58 patients at either catheterization or last available follow-up. CONCLUSIONS Percutaneous closure of PDA should be considered even in infants ≤6 kg.