Yuan Bai

An Integrated Pericardial Valved Stent Special for Percutaneous Tricuspid Implantation: An Animal Feasibility Study

BACKGROUND Various percutaneous valve replacement approaches have been reported in animals to replace the aortic and pulmonary valve. To broaden the indications of percutaneous approach to atrioventricular valves replacement, we developed a novel valved stent and evaluated the feasibility and safety of percutaneous implantation of the device in the tricuspid position. MATERIALS AND METHODS A unidirectional semilunar valve of porcine pericardium was sutured to a valvular ring. Then the ring with pericardial valve was mounted on a double-edge nitinol stent to construct the tricuspid valved stent. Transcatheter tricuspid valved stent implantation was performed on 10 healthy sheep. These sheep were followed up shortly after procedure with echocardiography evaluation and 64-slice CT imaging examination during the periodical follow-up at 1 mo and at 6 mo post-implantation. Additionally, two sheep were sacrificed after the procedure for anatomic and histological evaluation one at 1 h and the other at 1 mo, respectively. RESULTS Percutaneous valve implantation was successful in eight of 10 sheep. Two sheep died during the procedure due to migration of stent and fatal arrhythmia. The pressure of right heart did not significantly change after the procedure. Further echocardiography and imaging confirmed the stents were in desired position during the follow-up. The remaining six sheep with normal valvular and cardiac functionality survived for 6 mo after implantation. CONCLUSIONS The tricuspid stent with a valvular ring and pericardial valve can be implanted in tricuspid annulus percutaneous. The double-edge stent could substitute the native tricuspid valve chronically.

Complete atrioventricular block after percutaneous device closure of perimembranous ventricular septal defect: A single-center experience on 1046 cases

BACKGROUND Complete atrioventricular block (cAVB) has been deemed a rare complication after transcatheter closure for ventricular septal defect (VSD). However, this serious event appears to be underrecognized and is worth being investigated further. OBJECTIVES To determine the incidence and predisposing factors of cAVB associated with closure of VSD using a modified double-disk occluder (MDO). METHODS From December 21, 2001 to December 31, 2014, 1046 patients with perimembranous ventricular septal defect underwent percutaneous closure using the MDO. Electrocardiography was evaluated before the procedure, within 1 week after the procedure, and then at 1, 3, 6, and 12 months and every year thereafter. Other baseline and procedural parameters were also evaluated and a comparison between patients requiring pacemakers and those not suffering from cAVB was done. RESULTS cAVB occurred in 17 patients (1.63%) after the procedure. Of the 17 patients, 8 underwent permanent pacemaker (PPM) implantation. The cAVB occurred within 30 days after the procedure in 14 patients and after 1 year in 3 patients. In comparison patients aged ≤18 years, patients aged >18 years were more prone to cAVB (P = .025). Logistic regression revealed no significant parameter to predict later requirement for PPM. CONCLUSIONS The incidence of cAVB after transcatheter closure of VSD was acceptable, as part of the cAVB population recovered after administration of corticosteroid and application of a temporary pacemaker. Late cAVB (>1 year) appears to make it more difficult to restore normal conduction block. Because of the recurrence of cAVB, life-long follow-up with periodic electrocardiography examination may be mandatory.

Use of a novel valve stent for transcatheter pulmonary valve replacement: An animal study

OBJECTIVE The goal of this study was to evaluate valvular functionality after transcatheter pulmonary valve replacement in sheep using a novel pulmonary valve stent. METHODS Fresh porcine pericardium cross-linked with 0.6% glutaraldehyde was treated with L-glutamine to eliminate glutaraldehyde toxicity and sutured onto a valve ring before mounting on a nitinol stent to construct the pulmonary valve stent. Percutaneous femoral vein transcatheter pulmonary valve replacement was performed with the newly constructed valve stent. Pulmonary valve stents were implanted in 10 healthy sheep (6 males and 4 females) weighing an average of 25.7 +/- 4.1 kg. Color Doppler echocardiography, 64-row computed tomography, and direct catheter examination were used to assess valvular function. RESULTS Implantation was successful in 8 sheep. Shortly after surgery, all artificial valve stents exhibited normal open and close functionality and no stenosis or insufficiency. Heart rate was slightly elevated at this time, while all other hemodynamic parameters were normal. Six-month follow-up revealed no evidence of valve stent dislocation and normal valvular and cardiac functionality. There was no evidence of stent fracture. Repeated valve stent implantation was well tolerated as indicated by good valvular functionality 2 months postdelivery. CONCLUSION The novel pulmonary valve stent described herein can be delivered via percutaneous femoral vein transcatheter implantation and is highly efficacious at 6 months postdelivery. Furthermore, repeated valve stent replacement was successful.

Animal Experimental Study of the Fully Biodegradable Atrial Septal Defect (ASD) Occluder

This study was conducted to evaluate the feasibility, safety, biocompatibility, and degradation features of a fully biodegradable occluder for closure of atrial septal defect (ASD) in an acute canine model. The ASD was created in 20 healthy mongrel dogs by the brockenbrough needle, and the fully biodegradable occluders were implanted by self-made delivery system. The success rate and complications were observed. Acute ASD models were successfully created in 18 dogs, and 16 occluders were successfully implanted in the ASD models. Animals were sacrificed at different times after procedure. The cardiac gross anatomy showed that all occluders were stable in the interatrial septum, no vegetation or thrombus formation was observed on the surface of all occluders. They were embedded into endogenous host tissue gradually at 12-week follow-up. Different periods of pathological observations suggested that the occluders degraded gradually over about 24 weeks and essentially became an integral part of the septum. Transcatheter closure of ASD in acute canine model using the fully biodegradable ASD occluder has the potential of a high successful rate of technique, excellent biocompatibility, and fewer complications with adequate, immediate, and short-term results.

Transcatheter closure of postoperative residual perimembranous ventricular septal defects.

BACKGROUND The presence of postoperative residual perimembranous ventricular septal defect (PmVSD) is relatively uncommon. However, reoperation might be associated with an increased surgical risk. Transcatheter device closure is an alternative strategy for management of postoperative residual defects. METHODS Between July 2002 and November 2008, transcatheter closure of postoperative residual PmVSDs was attempted in 26 patients (11 male, 15 female). Symmetric and asymmetric PmVSD occluders were used. RESULTS The diameter of residual defects was from 3 mm to 10 mm (mean 6.3 +/- 2.3 mm) on transthoracic echocardiography. In 24 of 26 patients, the residual defects were successfully closed. No direct residual defect was found on left ventriculography after the procedure. Total occlusion rate was 62% (15 of 24) at completion of the procedure, rising to 71% (19 of 24) at one week and 96% (23 of 24) during the follow-up. Twenty patients had only one device implanted, whereas 4 patients had two devices implanted. The waist size of occluders used ranged from 5 mm to 12 mm (mean 8.6 +/- 2.5 mm). One patient presented with complete atrioventricular block 3 days after the procedure and recovered 2 weeks later. Hemolysis occurred in 3 patients after the procedure within 12 hours. These patients recovered 4 weeks, 4 days, and 8 days later, respectively. During follow-up, the devices were in a stable position with optimal shapes. No late complications were observed. CONCLUSIONS Transcatheter closure of postoperative residual PmVSDs is possible without the need for reoperation. The early and midterm prognosis of patients with transcatheter closure is good.

Percutaneous Closure of Perimembranous Ventricular Septal Defect with Modified Double-disk Occluder: What Is the Outcome at 10-year Follow-up?

OBJECTIVE Percutaneous closure of perimembranous ventricular septal defect is one of the greatest challenges in interventional cardiology. The long-term follow-up data are still limited. This report presents our experience in percutaneous closure of perimembranous ventricular septal defect with modified double-disk occluder. DESIGN The study is a retrospective analysis of cases from the Changhai Hospital clinic database. SETTING We reviewed the clinic database from December 2001 to December 2005. PATIENTS We included 117 patients who underwent percutaneous closure of perimembranous ventricular septal defects. OUTCOME MEASURES Procedural data and complications were assessed by an expert panel of cardiologists. RESULTS Device implantation was successfully accomplished in 113 of a total 117 patients (96.6%). The mean age was 31.1 ± 12.5 years (range 2-56 years). The patients were followed for a period of 86-134 months. The diameter of defect was 2-15 mm (mean 4.9 ± 2.9 mm). The ventricular septal defect rim below the aortic valve was 1-5 mm. The mean diameter of device used was 6.9 ± 3.7 (range 4-24 mm). Four patients presented complete atrio-ventricular block within 1 week after the procedure and recovered within 3 weeks. No other patient encountered serious adverse events during the follow-up. CONCLUSIONS Percutaneous closure of ventricular septal defect is safe and effective in most selected patients with modified double-disk occluder. Additional studies with larger cohorts and longer follow-up are needed to evaluate its safety.

Simultaneous Transcatheter Treatment of Perimembranous Ventricular Septal Defect and Other Congenital Cardiopathies

OBJECTIVE To assess the efficacy and safety of simultaneous transcatheter corrections of perimembranous ventricular septal defect (VSD) and other congenital cardiopathies. PATIENTS/METHODS From 2004 to 2012, 56 patients (25 male, 31 female), aged 14.2±10.1, with compound congenital cardiovascular abnormalities underwent simultaneous transcatheter interventional procedure. Of the 56 patients, 32 had VSD and atrial septal defects (ASD); 17 had VSD and patent ductus arteriosus (PDA); and seven had VSD and pulmonary valve stenosis (PS). Percutaneous balloon pulmonary valvuloplasty (PBPV) was performed before the closure of VSD, PDA, or ASD. RESULTS The combined transcatheter interventional procedure was successfully performed in all patients. Among these, two occluders were implanted in each of 49 patients, seven patients with VSD combined with PS underwent successfully balloon valvuloplasty and VSD closure. The size of VSD, ASD and PDA detected by TTE was 4.8±1.7 mm, 9.0±5.0 mm and 4.5±2.5 mm, respectively. The occluder diameter of VSD, ASD and PDA was 7.6±2.2 mm, 14.3±6.2 mm and 7.9±3.2 mm, respectively. The peak-to-peak transpulmonary gradient decreased from 60.4±19.7 mmHg to 15.0±5.0 mmHg (p<0.001) in seven patients with VSD combined with PS. One patient with VSD and ASD had a permanent pacemaker implanted because of third-degree atrioventricular block two months after the procedure. There were not serious adverse events in relation to the combined procedures during the 23.8±20.7 months of follow-up in other 55 patients. CONCLUSION The simultaneous treatment of VSD and other congenital cardiopathies using transcatheter-based procedures is safe and effective, which can provide satisfactory results.

Development and preclinical evaluation of a biodegradable ventricular septal defect occluder.

This study evaluated the feasibility, effectiveness, and safety of a biodegradable (BD) occluder for closure of ventricular septal defect (VSD) in an acute canine model.

Transcatheter closure of medium and large congenital coronary artery fistula using wire-maintaining technique

BACKGROUND For medium and large coronary artery fistula (CAF), the initially selected device sometimes has to be exchanged by reconstruction of track wire loop due to the complexity of CAF. OBJECTIVES We sought to evaluate the feasibility and safety of transcatheter closure of medium and large CAF by using the wire-maintaining technique (WMT). METHODS A total of 18 patients aged 15-56 years with congenital CAF underwent percutaneous transcatheter closure by WMT between April 2006 and October 2012. The immediate and long-term outcomes were evaluated. RESULTS Of the 18 patients (11 females), 16 (88%) underwent successful transcatheter closure of fistula using WMT. The CAFs originated from the right coronary artery (67%), the left circumflex coronary artery (28%), and the left anterior descending coronary artery (5%). The drainage sites were the right ventricle (56%), right atrium (22%), left ventricle (11%), and coronary sinus (11%). The mean diameter of fistulas was 9.5±1.71mm and mean size of the devices was 13.6±3.03mm. An angiogram following device deployment showed complete occlusion in 11 patients, mild residual shunt in 2 patients, and trivial residual shunt in 3 patients. One patient had transient ST-T wave changes, and one patient had hemolysis after the procedure. Follow-up ranged from 1 month to 54 months (median 39 months). Echocardiogram showed trivial residual shunt in 3 patients at 6-month follow-up and in 1 patient at 12-month follow-up. Coronary artery thrombosis was observed in 1 patient by multislice computed tomography at 12-month follow-up. CONCLUSION For those patients with medium and large complex fistula, transcatheter closure of CAF can be performed by using the wire-maintaining technique.

Percutaneous reimplantation of a pulmonary valved stent in sheep: A potential treatment for bioprosthetic valve degeneration

OBJECTIVE Percutaneous pulmonary valve replacement has been recently introduced into clinical practice. Patients with transcatheter pulmonary valve replacement will definitely face the problems of valve degeneration. In addition to surgical re-replacement of the degenerated bioprosthetic valves, we studied the replacement of degenerated bioprosthetic valves with transcatheter reimplantation of stent-mounted pulmonary valves. METHODS Percutaneous pulmonary valve replacement was first performed in 6 sheep used a homemade valved stent. Two months after the initial procedure, the 6 sheep previously implanted with a valved stent underwent the same implantation procedure of a pulmonary valved stent. Hemodynamic assessment of the bioprosthetic pulmonary valve was obtained by echocardiography immediately post-implant and at 2 months follow-up. RESULTS All 6 sheep had successful transcatheter stent-mounted pulmonary valve replacement in the first experiment. After 2 months, reimplantation was successful in 5 sheep but failed in 1 sheep because the first valved stent was pushed to the bifurcation of the pulmonary artery by the delivery sheath. Echocardiography confirmed the stents were in the desired position during the follow-up. The remaining 5 sheep with normal valvular and cardiac functionality survived for 3 months after implantation. CONCLUSION Transcatheter stent-mounted bioprosthetic pulmonary valve reimplantation is feasible in an animal model and more convenient than open chest reimplantation.