Novel use of covered stents to treat profound cyanosis in a hepatic vein exclusion Fontan.

Fontan completion in patients with complex cardiac anatomy, and specifically heterotaxy syndrome, can present unique physiologic considerations. For example, existing venous connections may be "unmasked" after a cavopulmonary anastomosis operation. We present the case of a child with heterotaxy, dextrocardia, single-ventricle physiology, and anomalous hepatic venous drainage that resulted in profound shunting and cyanosis. We addressed the problem utilizing a novel strategy with a "fenestrated" covered stent.

Particle embolization of systemic-to-pulmonary collateral artery networks in congenital heart disease: Technique and special considerations.

Systemic-to-pulmonary artery collateral networks commonly develop in patients with single-ventricle physiology and chronic hypoxemia. Although these networks augment pulmonary blood flow, much of the flow is ineffective and contributes to cardiac volume loading. This volume loading can have detrimental effects, especially for single-ventricle patients. Some data suggest that occluding collaterals may improve outcomes after subsequent operations, especially when the volume of collateral flow is significant. Traditional practice has been to coil occlude the feeding vessel. We perform particle embolization of these collateral networks for two primary reasons. First, access to the feeding vessel is not blocked as collaterals may redevelop. Second, particles occlude the most distal connections. Thus, embolization with particles should be considered as an alternative to coil occluding the proximal feeding vessel.

Staged Palliation of Cyanotic Obstructive Lesions With a Modified Right Ventricular Outflow Procedure.

BACKGROUND: Traditional palliation for biventricular cyanotic congenital heart lesions often involves staging with systemic-to-pulmonary arterial shunts to secure pulmonary blood flow (PBF) in the newborn period prior to complete repair. However, shunts may lead to life-threatening events secondary to shunt occlusion or acute coronary steal. They may be associated with morbidity secondary to diastolic runoff, systemic steal and volume loading, and do not provide pulsatile flow which has the potential to promote pulmonary artery (PA) growth. We have alternatively performed modified right ventricular outflow (mRVO) procedures by establishing antegrade right ventricle-to-PA flow. METHODS: Retrospective review of data on all patients who underwent the mRVO procedure from 2013 to 2016, including anatomy, number of interstage catheterizations, reoperations, intensive care unit admissions, hypercyanotic episodes, interval to complete repair, and mortality. RESULTS: Seventeen nonconsecutive patients included tetralogy of Fallot (n = 14), pulmonary valve stenosis (n = 2), and 1 with pulmonary atresia-intact septum; 14 had significant branch PA stenosis. Median age of first mRVO procedure was 14 days (range 5-193), and median duration of follow-up was 15.3 months (range 4-47 months). No patients had post-palliation acute hypercyanotic episodes. Nine were admitted to the ICU for persistent interstage hypoxemia, 7 of whom required reintervention prior to complete repair, which was achieved in 11 patients. Two late deaths unrelated to mRVO occurred. CONCLUSIONS: The mRVO procedure is a potential option with satisfactory results. It avoids potential shunt-related sudden death. The physiology of the mRVO palliation may provide unique benefits by providing antegrade pulsatile PBF, facilitates catheter interventions, and avoids branch PA distortion and stenosis.

Transcatheter closure of patent ductus arteriosus using the AMPLATZER™ duct occluder II (ADO II).

OBJECTIVES: The study purpose is to evaluate the safety and efficacy of the ADO II device for closure of patent ductus arteriosus (PDA) in children. BACKGROUND: Transcatheter treatment of PDA has been evolving for 40+ years and is the treatment of choice. The AMPLATZER™ Duct Occluder (ADO) device was developed for larger diameter ducts and is not ideal in all PDAs. ADO II was developed for small to moderate-sized ducts. METHODS: This is a single-arm, multicenter study evaluating safety and efficacy of the ADO II device. Patients <18 years were screened for a PDA ≤5.5 mm in diameter and 3-12 mm in length. Right and left heart catheterization was performed, and hemodynamic data were obtained at the time of implant. The diameter of the left pulmonary artery (LPA) and descending aorta, and the presence of any pre-existing pressure gradients across the LPA or aortic arch were assessed at baseline and 6 months post-implant. RESULTS: A total of 192 patients were enrolled. The median implant time was 74 min. Median fluoroscopy time was 12 min. A retrograde (aortic) approach was used in 33% of procedures and demonstrated a statistically significant reduction in fluoroscopy time (P value = 0.0018) compared to an antegrade approach. The device was successfully implanted in 93% of patients, with complete closure in 98% of successful implantations. CONCLUSIONS: In this prospective study, the ADO II was safe and effective for closure of small to moderate PDAs. Implantation is simple and the ability for retrograde aortic delivery reduces procedure-related radiation exposure. © 2017 Wiley Periodicals, Inc.

"Not-so-identical" twins with trisomy 21 and perimembranous ventricular septal defects.

While trisomy 21 is a common genetic disorder in singletons, the incidence among identical twins is very rare, occurring in approximately 1-2 per 1000 twin gestations. Trisomy 21 is associated with high incidence of congenital heart defects, and commonly occurs with ventricular septal defects (VSDs). Physiologic burden of VSDs depends on prevalence of anatomic and other circulatory factors. A case of identical twins with trisomy 21 and large VSDs is described in the present report. Though genetically identical, phenotypes varied significantly. One twin was managed medically, while the other developed more significant heart failure, requiring operative repair.

Gain-of-function mutations in SMAD4 cause a distinctive repertoire of cardiovascular phenotypes in patients with Myhre syndrome.

Myhre syndrome is a rare, distinctive syndrome due to specific gain-of-function mutations in SMAD4. The characteristic phenotype includes short stature, dysmorphic facial features, hearing loss, laryngotracheal anomalies, arthropathy, radiographic defects, intellectual disability, and a more recently appreciated spectrum of cardiovascular defects with a striking fibroproliferative response to surgical intervention. We report four newly described patients with typical features of Myhre syndrome who had (i) a mildly narrow descending aorta and restrictive cardiomyopathy; (ii) recurrent pericardial and pleural effusions; (iii) a large persistent ductus arteriosus with juxtaductal aortic coarctation; and (iv) restrictive pericardial disease requiring pericardiectomy. Additional information is provided about a fifth previously reported patient with fatal pericardial disease. A literature review of the cardiovascular features of Myhre syndrome was performed on 54 total patients, all with a SMAD4 mutation. Seventy percent had a cardiovascular abnormality including congenital heart defects (63%), pericardial disease (17%), restrictive cardiomyopathy (9%), and systemic hypertension (15%). Pericarditis and restrictive cardiomyopathy are associated with high mortality (three patients each among 10 deaths); one patient with restrictive cardiomyopathy also had epicarditis. Cardiomyopathy and pericardial abnormalities distinguish Myhre syndrome from other disorders caused by mutations in the TGF-ß signaling cascade (Marfan, Loeys-Dietz, or Shprintzen-Goldberg syndromes). We hypothesize that the expanded spectrum of cardiovascular abnormalities relates to the ability of the SMAD4 protein to integrate diverse signaling pathways, including canonical TGF-ß, BMP, and Activin signaling. The co-occurrence of congenital and acquired phenotypes demonstrates that the gene product of SMAD4 is required for both developmental and postnatal cardiovascular homeostasis. © 2016 Wiley Periodicals, Inc.

Percutaneous Closure of Perimembranous Ventricular Septal Defects Using the Second-Generation Amplatzer Vascular Occluders.

Earlier attempts at percutaneous closure of perimembranous ventricular septal defects (Pm VSDs) were abandoned because of incidence of heart block likely as a result of device rigidity and/or oversizing. This is retrospective review and data reporting of patients who underwent percutaneous closure using the softer second-generation Amplatzer vascular occluders; namely the Amplatzer vascular plug, second generation, (AVP II) and the Amplatzer duct occluder, second generation (ADO II) in our institution. A total of 20 patients were identified; AVP II was used in 9 patients and ADO II in 11 patients. Median weight was 13.45 kg (range 6.5 to 76); age 28.5 months (range 11 to 352). After procedure, 4 were noted to have aortic insufficiency; trivial in 3 and mild in 1 (unrelated to the device). Mild tricuspid regurgitation possibly device or procedure related was seen in 4. Residual flow through the device was common after procedure and disappeared in all but 3, graded as trivial in 1, small in 2. Average follow-up period was 7.54 months ± 7.5 (1 day to 25 months). There was no incidence of heart block, bacterial endocarditis, hemolysis, device embolization, or fracture. The aortic insufficiency resolved in 1 patient and was estimated to be trivial in the remaining 3 patients. In conclusion, percutaneous closure of Pm VSDs using the softer new generation devices as the AVP II and the ADO II is feasible and safe. Longer follow-up and larger series are needed.

Systemic Semilunar Valve Replacement in Pediatric Patients Using a Porcine, Full-Root Bioprosthesis.

BACKGROUND: Management of systemic semilunar valve disease in growing, young patients is challenging. When replacement is necessary, use of a pulmonary autograft is sometimes not possible for anatomic, pathologic, or technical reasons or due to parental or patient preference. We employed a stentless, porcine, full-root bioprosthesis in this setting and report our outcomes. METHODS: Over 9 years (2005 to 2013), 24 patients of mean age 13.1 years (range, 3 months to 20.3 years) underwent operation for mixed stenosis and insufficiency in 16 of 24 (67%), pure insufficiency in 7 of 24 (29%), and pure stenosis in 1 of 24 (4%). Twenty patients had previous interventions of repair or replacement, valvuloplasty, or multiple operations. Survival, follow-up echocardiographic findings, and outcomes were documented. All patients were maintained on daily aspirin. RESULTS: There were no hospital deaths and no early or late deaths over a mean follow-up for 23 patients of 46.1 months (range, 14 months to 9.2 years). One patient moved abroad and was lost to follow-up. Echocardiographic follow-up (mean 34.0 months) demonstrated that no patient developed more than mild insufficiency or moderate stenosis. In total, 20 of 24 (83%) showed no insufficiency and 11 of 24 patients (46%) showed no stenosis. Near or complete normalization of left ventricular mass and dimension was demonstrated. There were no explants and no thromboembolic or bleeding events. CONCLUSIONS: When use of a pulmonary autograft is not an option, the porcine full-root bioprosthesis appears favorable for systemic semilunar valve replacement in the pediatric and young adult population. Of note, when prosthetic degeneration does occur, stenosis predominates rather than insufficiency. Longer term studies are warranted.

Achieving Benchmark Results for Neonatal Palliation of Hypoplastic Left Heart Syndrome and Related Anomalies in an Emerging Program.

BACKGROUND: Results of surgical management of hypoplastic left heart syndrome (HLHS) and related anomalies are often compared to published benchmark data which reflect the use of a variety of surgical and hybrid protocols. We report encouraging results achieved in an emerging program, despite a learning curve at all care levels. Rather than relying on a single preferred protocol, surgical management was based on matching surgical strategy to individual patient factors. METHODS: From 2010 to 2014, a total of 47 consecutive patients with HLHS or related anomalies with ductal-dependent systemic circulation underwent initial surgical palliation, including 30 Norwood stage I, 8 hybrid stage I, and 9 salvage-to-Norwood procedures. True hybrid procedures entailed bilateral pulmonary artery banding and ductal stenting. In the salvage-to-Norwood strategy, ductal stenting was withheld in favor of continued prostaglandin infusion in anticipation of a deferred Norwood procedure. Cardiac comorbidities (obstructed pulmonary venous return, poor ventricular function, and atrioventricular valve regurgitation) and noncardiac comorbidities influenced the choice of treatment strategies and were analyzed as potential risk factors for extracorporeal membrane oxygenation (ECMO) support or in-hospital mortality. RESULTS: Overall hospital survival was 81% (Norwood 83.3%, hybrid 88%, "salvage" 67%; P = .4942). Extracorporeal membrane oxygenation support was used for eight (17%) patients with two survivors. For cases with obstructed pulmonary venous return (n = 10, 21%), management choices favored a hybrid or salvage strategy (P = .0026). Aortic atresia (n = 22, 47%) was treated by a Norwood or salvage-to-Norwood. No cardiac, noncardiac, or genetic comorbidities were identified as independent risk factors for ECMO or discharge mortality in a multivariable analysis. CONCLUSIONS: Our emerging program achieved outcomes that compare favorably to published benchmark data with respect to hospital survival. These results reflect rigorous interdisciplinary teamwork and a flexible approach to surgical palliation based on matching surgical strategy to patient factors. With major associated cardiac/noncardiac comorbidity and antegrade coronary flow, a true hybrid with ductal stenting was our preferred strategy. For high-risk situations such as aortic atresia with obstructed pulmonary venous return, the salvage hybrid-bridge-to-Norwood strategy may help achieve survival albeit with increased resource utilization.

"How to do it": hybrid stent placement for pulmonary vein stenosis.

Pulmonary vein stenosis (PVS) is often progressive and severe. Surgical and percutaneous angioplasty are acutely successful; however, restenosis is common and many patients require multiple reinterventions. We perform intraoperative "hybrid" stent placement to deliver larger, stronger stents. Hybrid stent placement is well described for pulmonary arterial stenosis (PAS). The PAS data demonstrate that smaller stents are associated with rapid in-stent restenosis. Data from PVS in adults demonstrate superior outcomes with larger stents. Hybrid stent placement requires a strong collaborative effort between congenital heart surgeons and interventional cardiologists.

Catheter conversion of classic Glenn to bidirectional Glenn with closure of left central shunt years after surgical attempts.

Bidirectional Glenn shunt is usually performed in patients with single ventricle in preparation for a total cavo-pulmonary connection. We present a patient born with complex congenital heart disease consisting of single ventricle, pulmonary atresia, non confluent pulmonary arteries, and anomalous pulmonary venous return in whom surgical bidirectional Glenn was attempted. After multiple surgical attempts she was converted to a Classic Glenn and a central ascending aorta to left pulmonary artery shunt. Several years later by the aid of radiofrequency wire the occluded pulmonary artery segment was canalized establishing continuity between the two pulmonary artery branches with stenting of the intervening segment. The central shunt to the left pulmonary artery was subsequently embolized. Thus this patient was converted in the catheterization laboratory from the physiology of a classic Glenn to the more preferred bidirectional Glenn physiology.

Transhepatic approach for rehabilitation of stenosed pulmonary arteries.

Transhepatic cardiac catheterization and intervention is used in selected cases in our institution. A retrospective review of transcatheter interventions for the pulmonary artery was conducted. Forty-five transhepatic procedures were performed. Thirteen involved intervention, to rehabilitate the branch pulmonary arteries. The median weight of the patients was 9.9 Kg +/- 3.4. The patients' age ranged from eight months to 86 months (median 23 months). The largest sheath used was 7F. All the patients underwent success intervention with no complication related either to the transhepatic approach or the intervention. The branch pulmonary artery diameter increased from 4.5 +/- 2.2 mm to 7 +/- 3 mm. Most of the procedures were performed under conscious sedation / deep sedation protocol. Hemostasis was achieved in all patients by gradual sheath withdrawal, followed by application of upward pressure on the tract from the subcostal area. In the absence of patent femoral veins the transhepatic approach can be used to perform successful and safe interventions, to rehabilitate the pulmonary artery system. It may offer the additional advantage of using larger sheaths than would be felt appropriate for the femoral veins.

Preclosure pressure gradients predict patent ductus arteriosus patients at risk for later left pulmonary artery stenosis.

The objective of this study was to evaluate the incidence of pre-existing catheterization left pulmonary artery (LPA) gradients and correlation of these gradients with later LPA stenosis after successful patent ductus arteriosus (PDA) occlusion. We performed a single-center review of 130 patients with PDA closure from October 1993 to February 2005. We analyzed the pre-PDA closure LPA pressure gradients at catheterization to determine if these were predictive of late LPA stenosis. On follow-up, a V (max) >2 m/s by echocardiogram (transthoracic echocardiography; TTE) was considered indicative of possible LPA stenosis. Left lung perfusion of <35% was considered diagnostic of significant LPA stenosis. Post PDA closure, possible LPA stenosis by TTE was seen in 8 of 128 patients (6.25%). Seven of these eight had precatheter LPA gradients >7 mm Hg. Five of these had perfusion scans, three of the five had significant LPA stenosis, and two underwent LPA angioplasty. Patients with LPA catheter gradients >7 mm Hg were more likely to have possible LPA stenosis by TTE, significant LPA stenosis by lung scan, and intervention with LPA angioplasty. In conclusion, a preclosure main pulmonary artery-to-LPA pressure gradient >7 mm Hg was found in all patients who developed significant LPA stenosis on follow-up after transcatheter PDA closure. It appears likely that these patients have LPA abnormality rather than stenosis caused by the PDA occlusion device. Patients with preclosure LPA gradients >7 mm Hg should undergo follow-up evaluations for detection of significant stenosis and may require treatment if an important flow abnormality is documented.

Closure of external tunnel Fontan fenestration: a novel use of the Amplatzer vascular plug.

BACKGROUND: Newer modifications of the Fontan operation include the external tunnel conduit with placement of an elongated type of fenestration. Atrial septal defect closure devices used traditionally to close fenestrations have short connecting waists with retention discs on each side. These may not be suitable for this type of Fontan fenestration. The length of the fenestration may not allow proper expansion of the retention discs on these devices. The Amplatzer vascular plug, a new occlusion device without a centering waist or retention discs designed to close vascular malformation, can be placed entirely within an elongated tube or vessel. METHODS: A retrospective review was used to study patients who underwent catheter closure of Fontan fenestration in our institution. Only patients whose procedure was performed after the commercial release of the Amplatzer vascular plug were included in the study. RESULTS: The vascular plug was implanted in 4 of 10 patients who underwent fenestration closure. The plug was successfully placed in all four patients without protrusion into either the systemic or pulmonary venous side of the baffle. There were no incidences of embolization, hemolysis, or infective endocarditis. All the patients experienced significant improvement in oxygen saturation. The technical aspects of this device are discussed as well as its safe and effective use. The satisfactory follow-up evaluation also is reported. CONCLUSIONS: This study outlines a novel use of the Amplatzer vascular plug for successful closure of selected Fontan fenestrations.

Balloon dilation of the pulmonary valve in premature infants with tetralogy of Fallot.

Infants with tetralogy of Fallot (ToF) presenting with desaturation may require augmentation of the pulmonary blood flow, usually in the form of a Blalock-Taussig shunt. Shunts may result in a preferential increase in blood flow to one lung. They also may be associated with significant morbidity and possibly mortality of premature infants. Balloon dilation of the pulmonary valve is reported to improve saturation in early infancy. This report describes two premature infants (weighing, respectively, 1.8 and 1.6 kg) with ToF and desaturation for whom balloon dilation of the pulmonary valve showed good results. Neither infant required palliative surgery. At this writing, one infant has already undergone complete repair.

Intermediate follow-up following intravascular stenting for treatment of coarctation of the aorta.

BACKGROUND: We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques. METHODS AND RESULTS: Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up. CONCLUSIONS: Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

Procedural results and acute complications in stenting native and recurrent coarctation of the aorta in patients over 4 years of age: a multi-institutional study.

BACKGROUND: We report a multi-institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta. METHODS AND RESULTS: Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean=18.1 years). Successful reduction in the post stent gradient (<20 mm Hg) or increase in post stent coarctation to descending aorta (DAo) ratio of >0.8 was achieved in 97.9% of procedures. There was significant improvement (P<0.01) in pre versus post stent coarctation dimensions (7.4 mm+/-3.0 mm vs. 14.3+/-3.2 mm), systolic gradient (31.6 mm Hg+/-16.0 mm Hg vs. 2.7 mm Hg+/-4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43+/-0.17 vs. 0.85+/-0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation (n=6), intimal tears (n=8), and dissections (n=9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration (n=28), and balloon rupture (n=13). Peripheral vascular complications included cerebral vascular accidents (CVA) (n=4), peripheral emboli (n=1), and significant access arterial injury (n=13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% (P<0.001) was observed in procedures performed after January 2002. CONCLUSIONS: Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta.