Multicenter Experience for Early and Mid-Term Outcome of MyVal Transcatheter Pulmonary Valve Implantation.

Transcatheter pulmonary valve implantation (TPVI) is a surgical alternative for correcting dysfunctional right ventricular outflow tract in previously operated patients. MyVal transcatheter heart valve (THV) (Meril Life Sciences, India), a new transcatheter valve designed for aortic position has recently been reported to be implanted in pulmonary position. Myval transcatheter valve were implanted in patients with stenosed dysfunctional conduits, severe regurgitation from transannular patch or dysfunctional surgical pulmonary valves (Bioprosthesis). Procedural details and post-TPVI follow-up were analysed. Myval TPVI was used in Fifty three patients with median age of 15 years (IQR 12-19.5 years). Almost sixty percent of the patients were male, with a median weight of 50 kg (31-63 kg). Prestenting was used in more than 80 percent of patients (n = 45 patients), while 6 patients had a prior surgical valve implantation. After Myval TPVI implantation, the peak instantaneous gradient across the RVOT decreased from a median of 23.5 mmHg (IQR 10-53 mmHg) pre-procedure to 10 mmHg (IQR 5-16 mmHg) post-procedure. The median fluoroscopy time for the procedure was 35 min (IQR 23.5-44 min). The large sizes-mainly the 29-mm and 32 mm Myval (Navigator, Meril Life Sciences Pvt Ltd, India), were the most used size in 40% (n = 22) of the cases each. The median contrast volume used during the procedure was 247 mL (IQR 120-300 mL). Patients were followed for a median period of 360 days (IQR 164-525 days). At the last clinic follow-up, there was no tricuspid valve regurgitation. Moderate neo-pulmonary valve regurgitation was reported in three cases. Early experience of TPVI with MyVal is encouraging with procedural success in all patients and acceptable mid-term outcomes.

Effect of Interfacial Schemes on the Optical and Structural Properties of InAs/GaSb Type-II Superlattices.

Incorporating an intentional strain compensating InSb interface (IF) layer in InAs/GaSb type-II superlattices (T2SLs) enhances device performance. But there is a lack of studies that correlate this approach's optical and structural quality, so the mechanisms by which this improvement is achieved remain unclear. One critical issue in increasing the performance of InAs/GaSb T2SLs arises from the lattice mismatch between InAs and GaSb, leading to interfacial strain in the structure. Not only that but also, since each side of the InAs/GaSb heterosystem does not have common atoms, there is a possibility of atomic intermixing at the IFs. To address such issues, an intentional InSb interfacial layer is commonly introduced at the InAs-on-GaSb and GaSb-on-InAs IFs to compensate for the strain and the chemical mismatches. In this report, we investigate InAs/GaSb T2SLs with (Sample A) and without (Sample B) InSb IF layers emitting in the mid-wavelength infrared (MWIR) through photoluminescence (PL) and band structure simulations. The PL studies indicate that the maximum PL intensity of Sample A is 1.6 times stronger than that of Sample B. This could be attributed to the effect of migration-enhanced epitaxy (MEE) growth mode. Band structure simulations understand the impact of atomic intermixing and segregation at T2SL IFs on the bandgap energy and PL intensity. It is observed that atomic intermixing at the IFs changes the bandgap energy and significantly affects the wave function overlap and the optical property of the samples. Transmission electron microscopy (TEM) measurements reveal that the T2SL IFs in Sample A are very rough compared to sharp IFs in Sample B, indicating a high possibility of atomic intermixing and segregation. Based on these results, it is believed that high-quality heterostructure could be achieved by controlling the IFs to enhance its structural and compositional homogeneities and the optical properties of the T2SLs.

Transfemoral Perimembranous Ventricular Septal Defect Device Closure in Infants Weighing ≤ 10 kg.

Transcatheter closure of Perimembranous VSDs (PMVSD) remains challenging particularly in infants. The aim of this study is to evaluate the efficacy and safety of transfemoral PMVSD device closure in infants weighing ≤ 10 kg in a single centre. Retrospective review of departmental databases and medical charts to define patient cohort and collect demographic, procedural and follow-up data. Between July 2014 and March 2021, 16 patients underwent attempted transfemoral PMVSD device closure (12 retrograde) at a median age of 11 months (interquartile range [IQR] 9-15.5) and a median weight of 8.3 kg (IQR 7.2-9.5). All patients were either symptomatic, had progressive left heart dilation or had VSD associated valve regurgitation. Median defect size on pre-procedural transoesophageal echocardiography was 6.8 mm (IQR 6-8.5). Median device waist size was 6 mm (IQR 4.5-8). Successful device placement was achieved in 14 patients (88%). One patient developed moderate aortic and tricuspid valve regurgitation upon retrograde and antegrade device deployment, respectively, and subsequently underwent surgical closure. The second patient developed progressive aortic regurgitation (AR) 2 days post procedure, and also underwent surgical removal with no residual AR. There was no cases of device embolization and no femoral arterial compromise. On median follow-up of 40.5 months (IQR 25-64), none of the patients developed complete heart block. Three patients (18.75%) had small residual shunts at latest follow-up which have not required any further intervention. Device closure of PMVSD's in children weighing ≤ 10 kg is feasible and safe with good procedural success rates. Use of both the antegrade and retrograde approaches may be necessary depending on anatomical variances.