Chetan Mehta

Stenting of the right ventricular outflow tract

Objective To assess the indication, technical aspects, and outcome of stenting of the right ventricular outflow tract (RVOT) in the management of symptomatic patients with severely limited pulmonary blood flow. Methods Retrospective case note and procedure review of patients undergoing stenting of the RVOT over an 8 year period. Patients Between 2005 and 2012, 52 selected patients underwent percutaneous stent implantation into a very narrow RVOT to improve pulmonary blood flow. Median age at stent implantation was 63 (range 4–406) days and median weight was 3.8 (1.7–12.2) kg. Results 52 patients underwent stent implantation. Median procedure time was 57 (24–260) min and fluoroscopy time 16 (5.5–73) min. There was one procedural death (1.9%) and one emergency surgery (1.9%). Saturations increased from 71% (52–83%) to 92% (81–100%) (p<0.001). Two patients required early shunts due to inadequate palliation and two died from non-cardiac causes. Sixteen further catheter interventions were undertaken (balloon in 7, further stent in 9). Twenty-nine patients underwent delayed surgery (complete repair in 26, palliative in 3) at a median of 172 (52–758) days post-stenting. Left pulmonary artery Z score increased from a pre-interventional value of −1.75 (−4.96 to 0.67) to a pre-surgical value of −0.55 (−4.12 to 1.97), (p<0.01). Median right pulmonary artery Z score increased from −2.63 (−7.70 to 0.89) to −0.75 (−6.69 to 1.18) (p<0.01) . Seventeen patients remain well palliated after a median of 122 (40–286) days. Conclusions Stenting of the RVOT is an effective treatment option in the initial management of selected patients with very reduced pulmonary blood flow.

Clinical evaluation of the new Amplatzer duct occluder II for patent arterial duct occlusion

Background: Several devices such as coils and Amplatzer duct occluder (ADO) are used for catheter closure of patent arterial ducts (PDA). These carry a high success rate but residual shunts, suboptimal device orientation, and technical problems are encountered. The Amplatzer duct occluder II (ADO II) is designed to address these limitations. Objectives: To evaluate the technical features of the new ADO II device for PDA closure and document the immediate/early closure rate, complications and device behavior during implantation. Methods: Prospective, two center study from February 2008 to January 2009. Twenty‐seven patients (18 females) received the ADO II. The median age was 22 months (range: 7 months–68 years) and the median weight was 11.7 kg (range: 6.9–108). The median PDA diameter was 2.6 mm (range: 1–4.4). The approach was arterial in 13 and venous in 14 patients. Follow‐up included echocardiography at 1 day and 1 month postimplantation. Results: All implantations were technically successful with immediate complete angiographic closure in 21 and trivial contrast flow in six patients. The median procedure time was 43 min (range: 15–82) and the fluoroscopy time was 6 min (range: 2.2–26.5). Echocardiography confirmed no residual shunts on the following day. There were no complications. Conclusion: The new ADO II is a versatile and very effective device for closure of PDAs of various shapes, lengths, and up to diameters of 5.5 mm. The disc articulations, high early closure rate, arterial or venous approach options, and small diameter delivery catheter are all beneficial features.

Initial experience with the cook formula balloon expandable stent in congenital heart disease

Balloon expandable stents are an integral part in the catheter treatment of congenital heart disease. In the growing child, stents require dilatation to greater diameters over time. The Cook Formula stent is a recent 316 stainless steel open‐cell design licensed for peripheral vascular work.

Rapid Ventricular Pacing for Catheter Interventions in Congenital Aortic Stenosis and Coarctation: Effectiveness, Safety, and Rate Titration for Optimal Results

INTRODUCTION Infants and children with congenital aortic stenosis and coarctation of the aorta can be treated by catheter intervention. There are several pharmacological and mechanical techniques described to overcome the balloon movement; none, however, have proved entirely satisfactory. An alternative method to achieve balloon stability is the use of rapid ventricular pacing. We describe our experience with titrating the pacing rate and the use of this technique. METHODS A retrospective review of database was performed, to identify patients who underwent transcatheter intervention with rapid ventricular pacing. Invasive systemic pressures were documented with a catheter in the aorta. Rapid ventricular pacing was initiated at the rate of 180 per minute and increased by increments of 20 per minute to a rate required to achieve a drop in systemic pressure by 50% and a drop in pulse pressure by 25%. The balloon was inflated only after the desired pacing rate was reached. Pacing was continued until the balloon was completely deflated. RESULTS Thirty patients were identified, 29 of whom had interventions with rapid ventricular pacing. Balloon valvuloplasty of aortic valve was performed on 25 patients while 4 patients had stenting for coarctation by this technique. The rate of ventricular pacing required ranged from 200 to 260 per minute with a median rate of 240. Balloon stability at the time of intervention was achieved in 27 patients. CONCLUSION Rapid ventricular pacing is a safe and effective method to provide transient decrease in cardiac output at the time of transcatheter interventions to achieve balloon stability.

Catheter interventions in the staged management of hypoplastic left heart syndrome

AIM To analyse the current practice and contribution of catheter interventions in the staged management of patients with hypoplastic left heart syndrome. METHODS This study is a retrospective case note review of 527 patients undergoing staged Norwood/Fontan palliation at a single centre between 1993 and 2010. Indications and type of catheter interventions were reviewed over a median follow-up period of 7.5 years. RESULTS A staged Norwood/Fontan palliation for hypoplastic left heart syndrome was performed in 527 patients. The 30-day survival rate after individual stages was 76.5% at Stage I, 96.3% at Stage II, and 99.4% at Stage III. A total of 348 interventions were performed in 189 out of 527 patients. Freedom from catheter intervention in survivors was 58.2% before Stage II and 46.7% before Stage III. Kaplan-Meier freedom from intervention post Fontan completion was 55% at 10.8 years of follow-up. Post-stage I interventions were mostly directed to relieve aortic arch obstruction--84 balloon angioplasties--and augment pulmonary blood flow--15 right ventricle-to-pulmonary conduit interventions; post-Stage II interventions centred on augmenting size of the left pulmonary artery--73 procedures and abolishing systemic venous collaterals--32 procedures. After Stage III, the focus was on manipulating the size of the fenestration--42 interventions--and the left pulmonary artery -31 procedures. CONCLUSION Interventional cardiac catheterisation constitutes an integral part in the staged palliative management of patients with hypoplastic left heart syndrome. Over one-third (37%) of patients undergoing staged palliation required catheter intervention over the follow-up period.

Stereotactic Technique of Catheter Placement in the Stump of the Superior Vena Cava in Children with Impaired Venous Access

The long-term survival of children with irreversible intestinal failure is often dependent on adequate central venous access for the administration of parenteral nutrition. In children with occlusion of major central thoracic veins, innovative techniques to establish venous access have been described in the literature. The present report describes an innovative stereotactic technique of catheter insertion in children with occluded internal jugular and brachiocephalic veins. The catheter is inserted percutaneously from the neck into the distal patent stump of the superior vena cava communicating with the right atrium.

Right ventricular outflow tract stent versus BT shunt palliation in Tetralogy of Fallot

Objective This study sets out to compare morbidity, mortality and reintervention rates after stenting of the right ventricular outflow tract (RVOT) versus modified Blalock-Taussig shunt (mBTS) for palliation in patients with tetralogy of Fallot (ToF)-type lesions. Methods Retrospective case review study evaluating 101 patients (64 males) with ToF lesions who underwent palliation with either mBTS (n=41) or RVOT stent (n=60) to augment pulmonary blood flow over a 10-year period. Procedure-related morbidity, mortality and reintervention rates were assessed and compared. Results Admission rate to paediatric intensive care unit (PICU) was lower in the RVOT stent group (22% vs 100%; p<0.001). Thirty-day mortality in the RVOT stent group was (1/60 (1.7%)) compared with (2/41 (4.9%)) in the mBTS group (p=0.565). Mortality until surgical repair was comparable in both groups (5/60, 8.4%, including three non-cardiac death in the RVOT stent group vs 2/41, 4.9% (p=0.698)). Total hospital length of stay was shorter for the RVOT stent group (median 7 days vs 14 days; p<0.003). Time to surgical repair was shorter in the RVOT stent group (median 232 days, IQR 113–360) compared with the mBTS group (median 428 days, IQR 370–529; p<0.001) due to improved pulmonary arterial growth. Conclusion RVOT stenting in Fallot-type lesions can be accomplished safely, with lower PICU admission rate, a shorter hospital length of stay and shorter duration of palliation until complete repair compared with mBTS palliation.

Stenting of the left pulmonary artery after palliation of hypoplastic left heart syndrome

Left pulmonary artery stenosis and hypoplasia is a well‐recognized complication following surgical palliation of hypoplastic left heart syndrome. These lesions produce increased after load in a circulation in series so need to be effectively treated.

Transcatheter device closure of a traumatic ventricular septal defect

A traumatic ventricular septal defect (VSD) resulting from blunt chest injury is a very rare event in children. The clinical symptoms and timing of presentation are variable, so diagnosis and management of traumatic VSD may be challenging. Decision to close the traumatic VSD is usually based on a combination of severity of heart failure symptoms, hemodynamics, and defect size. We present a case of a 7-year-old boy who was run over by a truck and presented with head and liver injury initially. He was subsequently found to have a traumatic VSD. The VSD was closed percutaneously.

Outcome after transcatheter occlusion of patent ductus arteriosus in infants less than 6 kg: A national study from United Kingdom and Ireland

This study aimed to report our national experience with transcatheter patent ductus arteriosus (PDA) occlusion in infants weighing <6 kg.