Tarek S. Husayni

Inadvertent stenting of patent ductus arteriosus with Amplatzer Vascular Plug

We report a 12‐month old patient who presented for murmur evaluation after percutaneous closure of type C patent ductus arteriosus (PDA) using a 10 mm Amplatzer Vascular Plug (AGA Medical Corporation, Golden Valley, MN) at an outside institution. Echocardiography revealed a large left‐to‐right shunt through the implanted device, inadvertently stenting the PDA instead of closing it. The patient underwent repeat catheterization with successful coil implantation within the Amplatzer Vascular Plug, completely eliminating the large residual ductal shunt. Although challenging, this case illustrates the technique of implanting coils within this occlusion device. This case also illustrates that occlusion of type C PDA utilizing the Amplatzer Vascular Plug may not only result in incomplete occlusion but also create a potentially worse clinical situation in which the PDA is stretched larger and stented open. Without consideration of simultaneous coil implantation within this device, use of the Amplatzer Vascular Plug might be contraindicated in type C PDA, because there may be no way to ensure successful closure by the Vascular Plug alone.

Pre-existing left pulmonary artery stenosis and other anomalies associated with device occlusion of patent ductus arteriosus.

A retrospective analysis was performed on 200 consecutive patients who underwent cardiac catheterization for occlusion of Patent Ductus Arteriosus (PDA) at a single center by a single operator. Four significant anomalies were observed: pre‐existing Left Pulmonary Artery (LPA) stenosis, left recurrent laryngeal nerve (LRLN) injury, electrocardiogram (EKG) changes, and aorto‐pulmonary (AP) collateral arteries. The observation of pre‐existing LPA stenosis, marked EKG changes, and permanent LRLN injury have not been previously reported. Incidence, etiology, and clinical significance of these anomalies are discussed with specific new recommendations for the prevention of LRLN injury and occlusion of AP collaterals.

Aortic Aneurysm After Patch Aortoplasty for Coarctation: Analysis of Patch Size and Wall Growth

Aortic aneurysm may develop after surgery for coarctation of aorta especially patch aortoplasty. The size of patch and of adjacent native aortic wall was analyzed to determine whether aortic dilatation represents a true aneurysm. Electron beam tomography (EBT) was done on 19 patients, three months to 17.5 years after patch aortoplasty. Tomograms of aorta were obtained in 6-mm slices, and maximal cross-sectional area was digitized to obtain: total circumference (Ct), patch component (Cp), and aortic wall component (Cw). Ct, Cp, and Cw were normalized to the circumference of distal aorta (Cda) as: isthmus/distal aorta (Ct/Cda), patch segment/distal aorta (Cp/Cda), wall segment/distal aorta (Cw/Cda). Ct/Cda ranged from 109% to 260%. In 12 patients (group A), it varied from 168% to 260%; and in seven (group B), 109% to 133%. There was strong correlation (r = 0.92) between Ct/Cda and Cp/Cda. Ct/Cda, Cp/Cda, and Cp/Cw were higher in group A than B (p <0.001) but Cw/Cda did not differ. Cw/Cda was greater than the coarctation/distal aorta diameter ratios of preoperative angiograms, consistent with accelerated aortic wall growth postsurgery. No definite aneurysm was seen. Localized dilatation of aorta following patch aortoplasty in children is primarily due to a large synthetic patch and, partly, to increased aortic wall growth. Serial EBT or magnetic resonance imaging is indicated to monitor aortic wall growth and occurrence of aneurysm.

Proximal Sano Anastomosis Aneurysm Due to Degeneration of Bovine Pericardial Patch

We report a 5-year-old girl with hypoplastic left heart syndrome who originally underwent a Norwood procedure with a Sano shunt. Subsequent procedures included a bidirectional Glenn and extracardiac Fontan with a Gore-Tex graft (W.L Gore and Associates, Flagstaff, AZ). The patient was found to have a heart murmur on a follow-up visit 3 years later. Echocardiography and computed tomography imaging showed an aneurysm of the proximal Sano anastomosis. The patient underwent successful surgical repair.

Pharmacokinetics of Catecholamines During Hemofiltration in Pediatric Patients

Background: Continuous hemofiltration is used in pediatric patients with acute renal fail ure. Many of these patients are treated with catecholamines for hemodynamic instability. The authors studied the pharmacokinetics of dopamine and dobutamine on patients under going continuous venovenous hemofiltration. Methods and Results: Three critically ill pediatric patients with acute renal failure and car diovascular instability treated with hemofiltration and intravenous infusion of dopamine and/or dobutamine were entered into the study. Blood samples were drawn at steady-state levels from the arterial port (inflow) of the hemofilter, from the venous port (outflow) of the hemofilter, and from the ultrafilter. Sixteen (n = 16) pharmacokinetic measurements were made, six (n = 6) for dopamine and 10 (n = 10) for dobutamine. The clearance of dopamine by the hemofilter was 0.078 ± 0.011 mL/kg/min, and for dobutamine it was 0.036 ± 0.008 mL/kg/min. On the average, 0.56% of the dopamine dose and 0.13% of the dobutamine dose was removed by the hemofilter. Conclusions: The pharmacokinetics of dopamine and dobutamine at the dosage range of 5- 25 μg/kg/min are not altered by continuous hemoliltration. Relative to total plasma clear ance. negligible amounts of the drug were removed. The dosage of these catecholamines need not hc adjusted during continuous hemofiltration.