Use of endovascular stents in congenital heart disease

BACKGROUND. Balloon expandable intravascular stents have been used to support vessel walls in coronary and peripheral arteries in adults. The purpose of this study was to examine the efficacy and safety of these stents in the treatment of congenital heart disease. METHODS AND RESULTS. Forty-five stents were placed in 30 patients, who were 0.2-30.2 years old (weight, 3.5-76 kg). Patients with areas of stenosis that were difficult to approach surgically were chosen. Stents were mounted over balloons and placed by standard catheterization techniques. Twenty-three patients had branch pulmonary artery stenosis. Thirty-six stents were placed successfully and had reduced pressure gradients from 50.6 +/- 24 to 15.9 +/- 13.4 mm Hg. Five patients had stents placed after atrial surgery: three in obstructed Fontan repairs, one at the superior vena cava-right atrial junction after sinus venous defect repair, and one at the site of a Glenn shunt. Atrial stents reduced pressure gradients from 9.8 +/- 8.2 to 2.0 +/- 2.6 mm Hg. One patient had a stent placed in the descending aorta after coarctation dilation, and the pressure gradient was reduced from 50 to 25 mm Hg. One patient had pulmonary vein dilation with stent placement. Two stents migrated at the time of placement; one required surgical removal, and one was anchored in place by balloon dilation. One patient died within 24 hours of catheterization because of thrombus obstruction of the Fontan repair. Nine patients have undergone recatheterization. All stented vessels have remained at the same caliber as at original stent placement. CONCLUSIONS. We conclude that balloon expandable stents are useful in selected postoperative stenoses in congenital heart disease.     

A new Amplatzer device to maintain patency of Fontan fenestrations and atrial septal defects.

This study evaluated use of Amplatzer fenestrated device to maintain patency of the Fontan fenestration and atrial septal defect. Fenestrations are routinely created in patients with lateral tunnel or extracardiac Fontan. Spontaneous closure of the fenestration can lead to Fontan circulation failure. Other patients without single-ventricle physiology may benefit from a small communication between the left and right atria for decompression if closure of the atrial septal defect leads to failure of a dysfunctional ventricle. Amplatzer septal occluder device was modified to create a fenestration through the disks. Three patients with modified Fontan and one patient with a large atrial septal defect underwent placement of the device by transcatheter technique. The device deployment was guided by transesophageal echocardiography. The procedure was successful in all patients. Contrast injection after placement revealed patent fenestration with free flow. Follow-up ranged from 3 months to 1 year. All devices were patent by transthoracic echocardiography. These preliminary results suggest that the Amplatzer fenestrated device can serve as a valuable tool in failing Fontan circulation and may help to avoid surgical intervention. More studies are needed to assess long-term efficacy of the device.     

Use of covered Cheatham-Platinum stents in congenital heart disease

Background

Controversy remains regarding the use of covered stents in congenital heart disease (CHD). We evaluate the possibilities and safety of covered Cheatham-Platinum (CCP) stents in CHD.

Methods

Single-center retrospective CHD-database study of all CCP stents, 2003–2012. Three study groups: aortic coarctation (CoA), right ventricular outflow tract pre-stenting for percutaneous revalvulation (RVOT), and miscellaneous. Continuous data expressed as median (range).

Results

114 CCP stents in 105 patients, age 16.8 years (4.2–71.2).CoA group: 54 CCP stents in 51 patients: 3/54 for aneurysm exclusion, in 51/54 covering used “prophylactically” because of increased risk for vessel tear. Overall, CCP stenting increased the coarctation diameter from 6 mm (0–15) to 15 mm (10–20) (p < 0.001).RVOT group: 39 CCP stents in 37 patients (34 with RVOT graft, 3 with transannular patch): the graft lumen had shrunken from nominal 21 mm (10–26) to 13 mm (5–22); with the CCP stent the RVOT was redilated to 22 mm (16–26, p < 0.001 vs stenosis).Miscellaneous group: 21 CCP stents in 17 patients: closure of Fontan-circuit fenestration (n = 5), restoration of superior caval vein (n = 2) or pulmonary artery (n = 3) patency, relief of supra-pulmonary stenosis (n = 2), exclusion of aberrant pulmonary arteries (n = 1), cavopulmonary conduit expansion (n = 2), Blalock–Taussig shunt flow reduction (n = 1), and defibrillator lead protection from sharp stents (n = 1). Hybrid procedures performed in 3/17 patients. CCP stent was used as rescue treatment in 2/patients to seal iatrogenic bleeding.

Conclusion

CCP stents can safely be applied in CHD patients. The covering allows adequate sealing of existing or expected tears, thereby increasing the safety margin with more complete dilation.     

Endovascular stents in congenital heart disease

Acquired or de novo vascular obstructions can adversely affect the outcomes of management algorithms for children with congenital heart lesions. Although surgical repair is frequently feasible, some acquired or congenital obstructions are difficult to address in the operating theater. Presented is the recent experience with endovascular stents to relieve such stenoses, and their impact on patient care.     

Use of coated stents in two patients with congenital heart defects and secondary vascular aneurysms

The formation of an aneurysm in the aorta or pulmonary artery is a dangerous potential complication of surgical and angioplasty procedures involving these vessels. Treatment using covered stents has emerged as an effective alternative to surgery and the use of conventional stents. The authors report on 2 patients who were treated successfully by the implantation of covered stents in the aorta and pulmonary artery following angioplasty and surgery, respectively. We discuss the mechanisms of aneurysm formation and the efficacy and limitations of using covered stents in such patients.     

Covered stents in patients with congenital heart defects.

OBJECTIVES: To evaluate the role of covered Cheatham-Platinum stents in patients with congenital heart disease. BACKGROUND: There are limited data in the literature about the use of covered stent in patients with congenital heart disease. METHODS: Between January 2004 and September 2005, covered Cheatham-Platinum stents were implanted into 18 patients with congenital heart defects (9 males, median age 19 years, range 8-45 years). Sixteen had aortic coarctation or recoarctation (8 with associated aneurysm, 1 with patent ductus arteriosus, 3 with an irregular wall, 4 with subatretic native aortic coarctation) (group 1). Two subjects with univentricular heart circulation were treated because of complex right-to-left shunting (Group 2). RESULTS: Group 1: The stents used ranged from 34 to 45 mm in length. The mean fluoroscopy and procedure times were 12+/-8 and 70+/-15 minutes, respectively. After implantation, the gradient across the stenosis decreased significantly (prestent median value 37 mmHg) (range 20-50 mmHg) versus poststent: median value 0 mmHg (range 0-10 mmHg) (P<0.0001). Vessel diameter increased from a median value of 6 mm (range 0-11) to a median value of 14 mm (range 10-23) (P<0.0001). Stents were placed in the correct position in all subjects. No complications occurred and on angiographic control the stenoses had been relieved and the aneurysms completely excluded. Group 2: Implantation of the covered stents successfully abolished right-to-left shunting in both patients. Both had significant increases in oxygen saturation and no complications occurred. Follow-up: During a median follow-up of 7 months (1-19 months), the results were stable without any complications. CONCLUSION: Covered Cheatham-Platinum stents are very useful tools for treating various congenital cardiovascular malformations.     

Intravascular and intracardiac stents used in congenital heart disease

Intravascular or intracardiac stenoses occur in many forms of congenital heart disease or after attempted surgical repair. Although balloon dilation is one option for management, restenosis can occur due to elastic recoil immediately after the procedure. To address to such stenotic lesions, many reports support implanting endovascular stents to provide a framework for vessel expansion. Both balloon-expandable fixed tubular mesh stainless steel devices, and self-expandable stents have had an extensive clinical application. In pediatric patients, stents are used for a variety of stenoses, such as systemic venous obstruction pathways (eg, Mustard, Fontan baffle, or bidirectional cavopulmonary connections), pulmonary artery, right ventricular to pulmonary conduits, aortic coarctation, the arterial duct, aorticopulmonary collaterals, or postoperative systemic to pulmonary shunts. Because of improvements in device profile, implantation rates have increased. Complications such as stent fracture, migration, aneurysm formation, and in-stent restenosis occur but only rarely. This latter event may be because of intimal hyperplasia and/or continued vessel (and patient) growth related to the stent diameter. As such, some instances require redilation to manage the acquired lesion. Stent application has importantly altered management algorithms in congenital heart disease.     

Unusual stents in infants with severe congenital heart disease

Two infants with severe congenital heart disease requiring intervention are described. Although both required conventional surgical therapy, mitigating circumstances led to catheter intervention for short-term palliation. The feasibility and advisability of such procedures is discussed.     

Haemostatic defects in cyanotic congenital heart disease.

An investigation of defects of the haemostatic mechanism in 41 children with cyanotic congenital heart disease concluded that such abnormalities were common and normally involved factors synthesised in the liver, that is the vitamin K dependent factors (rothrombin, factors VII and IX) and factor V. No evidence was found of activation of the coagulation or fibrinolytic systems. The defects can be explained by deficient synthesis resulting from systemic hypoxia as well as from sluggishness of the local microcirculation caused by high blood viscosity. Vitamin K parenterally had no demonstrable effect. Replacement of these factors, possibly combined with measures to improve the microcirculation, therefore, appears to be the appropriate treatment.     

Haemostatic defects in cyanotic congenital heart disease.

An investigation of defects of the haemostatic mechanism in 41 children with cyanotic congenital heart disease concluded that such abnormalities were common and normally involved factors synthesised in the liver, that is the vitamin K dependent factors (rothrombin, factors VII and IX) and factor V. No evidence was found of activation of the coagulation or fibrinolytic systems. The defects can be explained by deficient synthesis resulting from systemic hypoxia as well as from sluggishness of the local microcirculation caused by high blood viscosity. Vitamin K parenterally had no demonstrable effect. Replacement of these factors, possibly combined with measures to improve the microcirculation, therefore, appears to be the appropriate treatment.     

胺碘酮对风湿性心脏病瓣膜置换术后心房颤动自动复律患者围术期的窦性心律维持作用

目的研究胺碘酮在风湿性心脏病瓣膜置换术后心房颤动(简称房颤)自动复律患者围术期的窦性心律(简称窦律)维持作用。方法84例瓣膜置换术后房颤自动复律的风湿性心脏瓣膜病患者随机分为试验组(n=44例)和对照组(n=40例)。对照组术后给予常规药物和安慰剂。试验组除常规药物外,术后加用胺碘酮。比较两组房颤复发率。试验终点为术后第30天。结果试验组房颤发生率小于对照组(P<0.05);术后30天窦律维持率试验组显著高于对照组(77.3%vs0,P<0.05)。结论胺碘酮能够有效地维持瓣膜置换术后房颤自动复律围术期的窦律,预防房颤的复发。     

Coronary artery disease in patients with congenital heart defects

The prognosis of patients with congenital heart defects has improved significantly: more and more patients reach adulthood and old age. At the same time, the possibility of cardiovascular morbidity increases. The conventional risk factors for coronary artery disease are at least as high or even higher in patients than in the general population. Obesity and sedentary life style are more common in adults with congenital heart defect (ACHD) than in general population. In some patients, for example those with coarctation of the aorta or patients with operated coronary arteries in the infancy, the incidence of coronary artery disease (CAD) is clearly increased. In some patients with cyanotic heart defects (e.g. Fontan), the incidence of CAD might be lower, but it usually returns to the average level or higher after correction of the defect. Coronary artery disease is one of the most important reasons for mortality also in ACHD patients, and the consequences of a coronary event might be more fateful in a patient with a corrected congenital heart defect than in her/his peer. There should be a paradigm shift from operative mortality and short‐term outcome to long‐term morbidity and prevention of cardiovascular disease – a task that often has been forgotten during follow‐up visits.