Surendranath R. Veeram Reddy

Trans-catheter closure of patent ductus arteriosus—What is the best device?†

Background: Over the past three decades, transcatheter occlusion of patent ductus arteriosus (PDA) has evolved to be the procedure of choice. Gianturco and Flipper coils are the most commonly used coils in the United States for closure of small and moderate size PDAs. For larger PDAs, interventionalists in the United States commonly use the Amplatzer Duct Occluder (ADO) and those in Europe use the ADO or the Nit‐Occlud Coils (NOC). A comparison between Gianturco coils, Flipper coils, ADO, and NOC has never been made. Objective: To compare the success and complication rate associated with the four different devices used for transcatheter closure of PDA. Success was defined as complete closure of PDA with absence of a residual shunt (R.S.) at six months follow‐up. Methods: Two institutions collaborated in combining their data to evaluate the results of transcatheter closure of PDA. Results: Totally, 546 patients underwent successful PDA occlusion at both institutions. Gianturco and Flipper coils were used in 120 (22%) and 119 (22%) patients respectively. A total of 152 (28%) patients received ADO and 155 (28%) patients received NOC. Immediate R.S. were noted in 226 (41.4%) patients in the entire study group with the NOC group having the highest percentage of R.S. (80/155, 51.6%, P = 0.004). Of the 484 patients with follow‐up echocardiograms at 6 months, 35 (7.2%) patients had persistent R.S. The NOC (3/143, 2.1%) and ADO (5/150, 3.3%) groups had the least R.S. at six months follow‐up. Conclusion: Per our definition of success, the Nit‐Occlud coils and the Amplatzer duct‐occluder devices had significantly higher success rate for PDA occlusion versus the coils.

A novel biodegradable stent applicable for use in congenital heart disease: bench testing and feasibility results in a rabbit model.

A novel double opposed helical (DH) biodegradable stent was designed and fabricated for CHD applications. The primary objective was to evaluate the feasibility of DH stent delivery and deployment in rabbit external iliac arteries (EIA). Secondary objectives were to assess stent patency, thrombosis and inflammation at 1‐week and 1‐month follow‐up.

Is it safe to perform cardiac catheterizations on adults with congenital heart disease in a pediatric catheterization laboratory

Objective: To determine the complication rate during the catheterization in adults with congenital heart disease (CHD) in a pediatric catheterization laboratory (PCL). Background: An increasing number of patients with CHD are surviving into adulthood, with diagnostic and interventional cardiac catheterization being essential for the management of their disease. The complication rate during the catheterization of adults with CHD has not been reported. Methods: A retrospective chart review was performed on all adult patients (>18 years) with CHD who underwent diagnostic or interventional catheterization in our PCL within the past 8.5 years. Results: A total of 576 procedures were performed on 436 adult patients (median age 26 years). Complex heart disease was present in 387/576 (67%) procedures. An isolated atrial septal defect or patent foramen ovale was present in 115/576 (20%) procedures, and 51/576 (9%) procedures were performed on patients with structurally normal hearts with arrhythmias. Interventional catheterization was performed in 378/576 (66%) procedures. There were complications during 61/576 (10.6%) procedures; 19 were considered major and 42 minor. Major complications were death (1), ventricular fibrillation (1), hypotension requiring inotropes (7), atrial flutter (3), retroperitoneal hematoma, pneumothorax, hemothorax, aortic dissection, renal failure, myocardial ischemia and stent malposition (1 each). The most common minor complications were vascular entry site hematomas and hypotension not requiring inotropes. Procedures performed on patients ≥ 45 years of age had a 19% occurrence of complications overall compared with 9% occurrence rate in patients of age < 45 years (P < 0.01). Conclusions: The complication rate during the catheterization of adults with CHD in a PCL is similar to the complication rate of children with CHD undergoing cardiac catheterization. The older subset of patients are more likely to encounter complications overall. The encountered complications could be handled effectively in the PCL. With screening in place, it is safe to perform cardiac catheterization on most adults with CHD in a PCL.

A novel design biodegradable stent for use in congenital heart disease: Mid-term results in rabbit descending aorta

This study evaluates the feasibility of delivery and deployment of low and medium molecular weight (LMW and MMW, respectively) double‐opposing helical (DH) poly‐l‐lactic acid biodegradable stent (BDS) in rabbit descending aorta (DAO). Secondary objectives were to assess patency and inflammation of stented vessels at 9 months and to investigate safety following intentional embolization of stent fragments in DAO.

Amplatzer vascular plug IV for occlusion of pulmonary arteriovenous malformations in a patient with cryptogenic stroke

Paradoxical embolism resulting in cryptogenic stroke has received much attention recently, with the primary focus on patent foramen ovale (PFO). However, it is essential to be vigilant in the search for other causes of paradoxical embolic events, such as pulmonary arteriovenous malformations (PAVM). We describe successful closure of pulmonary AVM with a St Jude Medical (Plymouth, MN) Amplatzer™ vascular plug IV. The newer AVP-IV devices can be used for successful embolization of tortuous pulmonary AVM in remote locations where use of other traditional devices may be technically challenging.

Left ventricular mechanical synchrony and global systolic function in pediatric patients late after ventricular septal defect patch closure: A three-dimensional echocardiographic study

BACKGROUND Patients with large ventricular septal defects (VSDs) undergo surgical patch closure during infancy. The long-term effects of the presence of akinetic patch in the ventricular septum and postoperative right bundle branch block (RBBB) on the left ventricular (LV) mechanical synchrony and global systolic function have not been studied. OBJECTIVE The objective of this study was to evaluate the long-term effects of an akinetic VSD patch and RBBB on the LV mechanical synchrony and global systolic function in pediatric patients more than 5 years after surgery. METHODS Eighteen asymptomatic VSD repair and 18 normal control patients were evaluated by an electrocardiogram and three-dimensional echocardiography. Left ventricular end-diastolic volumes (LVEDVs) and volumetric ejection fraction (EF) were calculated. Left ventricular intraventricular synchrony was assessed by the 16-segment volumetric dyssynchrony index. RESULTS Eight of 18 (44%) patients in the VSD repair group had RBBB. The LVEDV and volumetric EF were similar in the VSD repair and control groups. The LV dyssynchrony index was not significantly different between the VSD repair and control groups (2.46 +/- 1.77% vs. 1.75 +/- 1.08%, P = .16). The VSD repair group was then divided into two subgroups: patients with RBBB (8/18) and those without RBBB (10/18). The two subgroups were similar in demographics, LVEDV, and volumetric EF. However, the RBBB subgroup demonstrated significant LV mechanical dyssynchrony compared with the non-RBBB VSD subgroup (2.70 +/- 1.08% vs. 1.15 +/- 0.35%, P = .006). CONCLUSIONS Pediatric patients 5-10 years after VSD patch closure have a normal LV function. The presence of the RBBB causes some mechanical dyssynchrony and tendency toward LV dilatation in this group of patients. Therefore, long-term follow-up of these patients is warranted.

Novel bioresorbable stent coating for drug release in congenital heart disease applications

A novel double opposed helical poly-l-lactic acid (PLLA) bioresorbable stent has been designed for use in pediatrics. The aim was to test the PLLA stent biocompatibility. The PLLA stent was immersed into whole pigs blood in a closed loop circuit then fibrin and platelet association was assessed via enzyme-linked immunosorbent assay. D-Dimer was valued at 0.2 ± 0.002 ng/mL and P-selectin 0.43 ± 00.01 ng/mL indicating limited association of fibrin and platelets on the stent. To improve biocompatibility by targeting inflammatory cells, dexamethasone was incorporated on PLLA fibers with two coating methods. Both coatings were poly(l-lactide-co-glycolide) acid (PLGA) but one was made porous with sucrose while the other remained nonporous. There was no change in mechanical properties of the fiber with either coating of PLGA polymer. The total amount of dexamethasone released was then determined for each coating. The cumulative drug release for the porous fiber was significantly higher (∼100%) over 8 weeks than the nonporous fiber (40%). Surface examination of the fiber with scanning electron microscopy showed more surface microfracturing in coatings that contain pores. The biocompatibility of this novel stent was demonstrated. Mechanical properties of the fiber were not altered by coating with PLGA polymer. Anti-inflammatory drug release was optimized using a porous PLGA polymer.

Management and Outcomes of Heterotaxy Syndrome Associated With Pulmonary Atresia or Pulmonary Stenosis

BACKGROUND Historic outcomes of patients with heterotaxy and pulmonary atresia or pulmonary stenosis (PA/PS) have been poor and in the current era are incompletely described. We reviewed our management of these patients and associated risk factors for death. METHODS We retrospectively reviewed the records of all patients with heterotaxy and PA/PS treated in our institution from January 1, 2002, to August 31, 2012. Death data were also confirmed with the Social Security Death Index. The log-rank test was done to assess six risk factors for death. RESULTS We identified 42 patients with heterotaxy and PA/PS. Median age at the first operation was 6.5 days, and median follow-up was 3.5 years. Death data were complete for all patients. Overall mortality was 19% (8 of 42). The 30-day, 1-year, and 5-year mortality estimation was 4.76%, 12.3%, and 19.1% respectively, as determined by the Kaplan-Meier method. The log-rank test showed total anomalous pulmonary venous return (TAPVR) (p<0.05) and obstructed TAPVR requiring an operation at less than 30 days (p=0.001) were significant risk factors for death. CONCLUSIONS In the current era, surgical treatment of heterotaxy and PA/PS can result in good outcomes. Associated TAPVR and obstructed TAPVR requiring neonatal correction were noted to be risk factors for death.

Thermally processed polymeric microparticles for year-long delivery of dexamethasone

Dexamethasone-releasing poly(lactic-co-glycolic acid) (PLGA) microparticles were formulated using a solvent displacement technique with the addition of distillation aiming to increase drug delivery lifetime. Two PLGA copolymer ratios (50:50 and 75:25) were used to determine the influence of lactic acid and glycolic acid ratio on microparticle characteristics. The addition of distillation significantly slows the release of dexamethasone compared to traditional solvent removal via evaporation while still maintaining a therapeutic dosage. Microparticles formulated with PLGA 50:50 controllably release dexamethasone up to one year and 75:25 release up to two years in-vitro. The ratio of lactic acid to glycolic acid plays a significant role in microparticle stability, drug loading efficiency, and thermal properties. In all, this formulation technique offers new prospects for inflammation suppression in pediatric vascular and airway diseases.

New-onset cardiac rhabdomyoma beyond infancy in a patient with tuberous sclerosis complex

Cardiac rhabdomyomas in patients with tuberous sclerosis complex are usually detected antenatally or during infancy, with subsequent stabilisation or spontaneous regression. Development of a new cardiac rhabdomyoma beyond infancy is very rare. We report a male child who needed resection of a large rhabdomyoma in neonatal life, and then developed a new-onset rhabdomyoma at 2 years of age in a different location, needing another resection. Routine surveillance for cardiac rhabdomyomas in asymptomatic patients with tuberous sclerosis is essential.