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Biomedical subjects

Zahid Amin

Publications and source records attributed to Zahid Amin.

11 recordsLinked to original sources
PubMed2006

Use of Amplatzer fenestrated atrial septal defect device in a child with familial pulmonary hypertension.

In a 4.5-year-old child with refractory pulmonary arterial hypertension, we performed atrial septostomy with the application of an Amplatzer fenestrated device designed to maintain patency. Continuous intravenous epoprostenol infusion was started concomitantly. Forty-two months after the procedure, the patient had no recurrent syncope and remained in New York Heart Association functional class II. Fenestration of the atrial septum is feasible in children with pulmonary artery hypertension. No conclusion regarding the patient's need for an atrial septal defect can be drawn since concomitant prostanoid therapy was administered. The long-term patency of the atrial communication needs further confirmation and the optimal timing for its application has to be determined.

Cardiac Catheterization↗
PubMed2006

Robotically assisted perventricular closure of perimembranous ventricular septal defects: preliminary results in Yucatan pigs.

OBJECTIVE: Robotic systems allow surgeons to perform minimally invasive cardiac surgery in adults. Experience in the pediatric population, however, is limited. Perventricular closure of muscular ventricular septal defects has been reported in humans but requires a median sternotomy. The objective of this study was to assess the feasibility of robotically assisted closure of perimembranous ventricular septal defects by using the perventricular approach. METHODS: The procedure was attempted in 7 pigs with naturally occurring perimembranous ventricular septal defects. Echocardiography was performed to confirm the presence and assess the size of the defect. A 3-armed da Vinci system consisting of two 8-mm instrument ports and a 12-mm endoscopy port was used. A pericardiotomy was performed, and the right ventricular free wall was visualized. A spinal needle was advanced into the right ventricular cavity. By using echocardiographic guidance, a glide wire was advanced through the angiocatheter and manipulated through the defect into the left ventricle or the ascending aorta. A delivery sheath was advanced over the wire. An appropriately sized Amplatzer device was deployed through the sheath. RESULTS: The procedure was successful in 5 pigs. One device was removed because it was smaller than the defect and an appropriately sized device was not available. The placement failed in the second pig in the series. Four pigs were followed up for 1 to 4 months. Angiograms performed before the pigs were killed documented complete occlusion in 3 and mild-to-moderate shunt in 1. CONCLUSIONS: Robotically assisted perventricular closure with the Amplatzer Membranous VSD Occluder is feasible. This approach avoids the associated morbidities of cardiopulmonary bypass and median sternotomy. Further investigation and refinements are needed, however, before application of this approach in humans.

Animals↗
PubMed2006

Transcatheter closure of perimembranous ventricular septal defects using the new Amplatzer membranous VSD occluder: results of the U.S. phase I trial.

OBJECTIVES: This phase I study attempted to report the initial safety and efficacy results of transcatheter closure of perimembranous ventricular septal defects (PmVSDs) using the new Amplatzer Membranous VSD Occluder (AGA Medical Corp., Golden Valley, Minnesota) in the U.S. BACKGROUND: The most common congenital heart disease is PmVSD. Surgical repair is widely accepted, but still carries a small but definite risk of morbidity and mortality. METHODS: Between October 2003 and August 2004, a total of 35 patients with PmVSD underwent an attempt of transcatheter closure under transesophageal and/or intracardiac echocardiographic guidance. The median age was 7.7 years (range, 1.2 to 54.4 years) and median weight was 25 kg (range, 8.3 to 110 kg). The median Qp/Qs ratio was 1.8 (range, 1 to 4), and the median VSD size as assessed by echocardiography was 7 mm (range, 4 to 15 mm). RESULTS: The attempt to place a device was successful in 32 patients (91%). The median device size used was 10 mm (range, 6 to 16 mm). The complete closure rates by echocardiography at 10 min (transesophageal/intracardiac), 24 h, 1 month, and 6 months (transthoracic) were 47% (15/32), 63% (20/32), 78% (25/32), and 96% (27/28), respectively. The median fluoroscopy time was 36 min (range, 14 to 191 min), and the median total procedure time was 121 min (range, 67 to 276 min). Three patients (8.6%) had serious adverse events of complete heart block, peri-hepatic bleeding, and rupture of tricuspid valve chordae tendineae. No other patient encountered serious adverse events during the follow-up. CONCLUSIONS: Transcatheter closure of a PmVSD is technically feasible and seems safe enough in children over 8 kg in weight to warrant continuation of clinical trials to assess the long-term safety and efficacy.

Adolescent↗
PubMed2004

Transcatheter closure of postinfarction ventricular septal defects using the new Amplatzer muscular VSD occluder: Results of a U.S. Registry.

The objective of this study was to assess the immediate and mid-term results of transcatheter closure of postinfarct muscular ventricular septal defects (VSDs) using the new Amplatzer postinfarct muscular VSD device (PIMVSD). Ventricular septal rupture occurs in 0.2% of myocardial infarcts and remains associated with very high morbidity and mortality. Data were prospectively collected for 18 patients who underwent attempted device closure of postinfarction VSDs between 2000 and 2003. Five patients underwent the closure in the acute phase (within 6 days from the infarct); the remaining patients underwent closure on day 14-95 after the diagnosis of the infarct. Outcome parameters included procedural success, evidence of residual shunts on echocardiography, and occurrence of procedure-related complications. The procedure was successful in deploying a device across the VSD in 16 of 18 patients. The 30-day mortality was 28%. Eleven patients are still alive and have been followed up for a median of 332 days. Two patients required a second procedure to close a residual VSD. At the most recent outpatient follow-up, the VSD was completely closed in two patients, six patients had a trivial or small residual shunt, and two patients had a moderate residual shunt. We conclude that percutaneous device closure of postinfarction VSDs using the Amplatzer PIMVSD occluder appears to be safe and effective. Further trials are required to assess long-term efficacy and compare the results with those of surgical closure.

Aged↗
PubMed2004

Erosion of Amplatzer septal occluder device after closure of secundum atrial septal defects: review of registry of complications and recommendations to minimize future risk.

The objectives of this study were to identify possible risk factors that may lead to erosion of the Amplatzer septal occluder (ASO) and recommend ways to minimize future risk. There have been rare occurrences of adverse events with development of pericardial effusion after ASO placement. Identification of high-risk cases, early recognition, and prompt intervention may minimize the future risks of adverse events. In all patients who developed hemodynamic compromise after ASO placement, echocardiograms (pre-, intra-, and postprocedure), atrial septal defect (ASD) size (nonstretched, stretched), size of the device used, cineangiograms, and operative records were reviewed by a panel selected by AGA Medical Corporation. The findings were compared to the premarket approval data obtained from FDA-approved clinical trials that were conducted in the United States, before the device was approved. A total of 28 cases (14 in United States) of adverse events were reported to AGA Medical. All erosions occurred at the dome of the atria, near the aortic root. Deficient aortic rim was seen in 89% and the defect described as high ASD, suggesting deficient superior rim. The device to unstretched ASD ratio was significantly larger in the adverse event group when compared to the FDA trial group. The incidence of device erosion in the United States was 0.1%. The risk of device erosion with ASO is low and complications can be decreased by identifying high-risk patients and following them closely. Patients with deficient aortic rim and/or superior rim may be at higher risk for device erosion. Oversized ASO may increase the risk of erosion. The defect should not be overstretched during balloon sizing. Patients with small pericardial effusion at 24 hr should have closer follow-up.

Adolescent↗
PubMed2004

Intraoperative device closure of perimembranous ventricular septal defects without cardiopulmonary bypass: preliminary results with the perventricular technique.

OBJECTIVE: In infants undergoing closure of perimembranous ventricular septal defects, cardiopulmonary bypass remains one of the factors that prolongs hospital stay and morbidity. A new technique was used to close the defects under echocardiographic guidance without cardiopulmonary bypass to prevent the deleterious effects of bypass. METHODS: Recently, the Amplatzer membranous ventricular septal defect device (AGA Medical Corp, Golden Valley, Minn) was introduced. The device has a double-disc design with a short connecting waist. The left ventricular disc has an eccentric design to prevent encroachment on the aortic valve leaflets. Eight Yucatan miniature pigs with naturally occurring perimembranous ventricular septal defects underwent closure of the defect in the operating room by using the perventricular technique. After median sternotomy, a purse-string suture was placed on the free wall of the right ventricle. An angiocatheter was advanced in the right ventricle, and through the catheter, a wire was advanced from the right ventricle through the ventricular septal defect into the left ventricle. A delivery sheath and the dilator were advanced over the wire. The wire and catheter were removed, and an appropriately sized Amplatzer membranous device was advanced through the sheath. The device was deployed under echocardiographic guidance with the heart beating. RESULTS: The procedure was successful in all animals. There was no incidence of device embolization, heart block, or aortic insufficiency. Angiograms at 3 and 6 months revealed no residual defects and no aortic insufficiency. Pathologically, the devices were completely endothelialized when examined grossly. CONCLUSIONS: The perventricular technique appears to be excellent for closure of perimembranous ventricular septal defects in the operating room. The technique might be feasible in smaller babies, who are high-risk candidates for closure in the catheterization laboratory. Cardiopulmonary bypass and prolonged hospital stay are avoided.

Animals↗
PubMed2003

The Genesis stent: A new low-profile stent for use in infants, children, and adults with congenital heart disease.

Placement of intravascular stents that can reach adult size in infants and smaller children has been limited by the large profile and poor flexibility of currently available stents. In vitro and in vivo testing of the Genesis stent was performed to evaluate crimpability, predeployment flexibility, and radial strength. Comparisons were made to the Palmaz iliac and IntraStent (IS) LD stents. Nine physicians placed 30 Genesis stents in swine pulmonary and systemic arteries to evaluate stent deliverability/crimpability. Two swine were recovered and underwent a second catheterization 8 weeks later, where the stents (n = 8) were reexpanded to maximal size. Angiographic and intravascular ultrasound (IVUS) assessments were performed. In vitro testing revealed the Genesis stent to have superior crimpability, flexibility, and comparable radial strength to the Palmaz iliac stent, and superior crimpability and radial strength and comparable flexibility to the IS LD series. During in vivo testing, the physicians graded the Genesis stent superior to the Palmaz stent regarding crimpability and deliverability, and superior to the IS LD stent in regard to crimpability, and comparable to or superior in deliverability. In the chronic animals, the Genesis stent was expanded up to maximal diameter 8 weeks following implantation. Angiographic and IVUS revealed no fractures no in-stent restenosis. The Genesis stent can be easily delivered through smaller sheaths, which will facilitate their use in infants and smaller children with vascular stenosis.

Adult↗
PubMed2003

Extension of transcatheter coil occlusion to the treatment of complex coronary fistulas.

Coronary fistulas can be a source of myocardial Ischemia when they are large. In this case series, we describe four complex coronary fistulas treated by transcatheter occlusion. The first two with Gianturco coils and the other two with an Amplatzer PDA device. Transcatheter closure of coronary fistulas can be accomplished in most cases.

Child, Preschool↗
PubMed2002

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.

Angioplasty, Balloon, Coronary↗