Information for Use

Device Name: Sinus Venosus Atrial Septal Defect Device (VB Stent)

Indication for Use: The (VBS) Sinus Venosus Atrial Septal Defect Device is indicated for use in the treatment of defects in the superior vena cava and atrial septum which causes shunt between the systemic and pulmonary veins or the left atrium. 

Contraindications:

1. Patients too small to allow safe delivery of the stent without compromise to the systemic vein used for delivery
2. Unfavorable anatomy (scarring or thrombus in the vein so that it does not dilate with struct strength of the device
3. Curved vasculature anatomically or unsuitable vasculature due to the position of the pulmonary vein draining into the SVC or not having adequate size atrial septal defect.
4. Occlusion or obstruction of systemic vein precluding delivery of the stent;
5. Clinical or biological signs of infection;
6. Active endocarditis;
7. Known allergy to aspirin, other antiplatelet agents, or heparin;
8. Pregnancy IV.

WARNINGS AND PRECAUTIONS

The warnings and precautions can be found in the VASD device.

The device is available in the following configurations:

1. BVS90X40X25
2. BVS75X35X25
3. BVS65X30X20

The device is made of self-expandable Nitinol stent partially covered with ePTFE coating.

The delivery system is triaxial in construction

The delivery catheter is compatible with 0.035” guidewires and 8-11 Fr introducers.

1. ALTERNATIVE PRACTICES AND PROCEDURES: There are several alternatives for the correction of Sinus venosus ASD and the traditional method is surgical closure. An alternative method of closure with covered stent has been described before. However, there is no device dedicated for the treatment of this condition. A patient should fully discuss these alternatives with his/her physician to select the method that best meets expectations and lifestyle.

MARKETING HISTORY

 The VASD device is currently marketed only in India.  The device has not been withdrawn from marketing for any reason related to its safety and effectiveness.

VIII. POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTH:

 Below is a list of the potential adverse effects (e.g., complications) associated with the use of the device. • Femoral or internal jugular vein injury, thrombosis or psuedoaneurysm • Stent Migration • Stent Stenosis • Stent Fracture • Venacaval rupture • Stent Malposition • Hematoma • Sepsis/infection • Thrombosis/Thromboembolism • AV fistula formation • Death • Transitory arrhythmia • Endocarditis • Bleeding • Cell necrosis at the site of implant • Cerebrovascular Incident •

SUMMARY OF PRECLINICAL STUDIES

1. Laboratory Studies
2. In vitro Product Testing Bench testing was performed on the SVASD device as described below. The samples were exposed to 2X Ethylene Oxide sterilization cycle prior to testing. All applicable testing for each stent configuration and the delivery system catheter was conducted with accessories representative of clinical use. Testing was conducted according to four corners of the available device unless otherwise noted. A matrix of tests performed and corresponding results are provided in Tables 3 and 4. Table 3. Summary of in vitro Product Testing for SVASD device Test Purpose/ Objective Test/Reference Articles Results Material Characterization Material Composition To identify the materials of construction of the stent and delivery system Test:

Stress Analysis (FEA) To demonstrate the range of stresses at critical locations on the stent during physiological loading Modeling based on the stent material properties and geometries All data demonstrated that the Fatigue Analysis and Goodman Diagram predicts the fatigue safety factor to be tested  throughout the area of the stent with tensile stress.

Accelerated Durability Testing To be performed

No central body approval process has been passed at the current stage.

Test: 10 units of SVASD device

2. MRI Compatibility Nonclinical testing and modeling of this device in magnetic fields of 1.5 and 3.0 Tesla showed that the device is MR Conditional. All sizes of the stent can be scanned safely under the following conditions: • Static magnetic field of 1.5 T and 3 T • Maximum spatial gradient magnetic field of 2500 gauss/cm (25 T/m) • Maximum MR system reported, whole body averaged specific absorption rate (SAR) of 2.0 W/kg for 15 minutes of scanning (Normal Operating Mode) To be confirmed
3. Biocompatibility The biological safety assessment of the SVASD stent family is classified, per ISO 10993-1, as blood-contacting, permanent (> 30 days) implant devices. Based on the results of the biocompatibility testing performed and leveraged, along with consideration of clinical use of the stent in the field, the device family and delivery system were determined to be biocompatible.

Carcinogenicity testing for the VBStent family was leveraged from the data contained within the Nitinol bases stent PMA in conjunction with a risk assessment and evaluation of clinical experience. A summary of the testing conducted on similar stents is provided separately.

Animal Studies

No animal testing of VB stent has been performed to date. As there are no animal model of SVASD and the biocompatibility of Nitinol and ePTFE has been extensively studied UpToDate, no attempts were made to perform animal studies.

STUDIES on 3D Printed Models

The device metrics were derived from CT and MRI images of 20 patients with SVASD presented to our institution. 12 patients (60%) were male, mean weight was 70.2 ± 22.3 kg, height was 167 ± 16 cm, and ASD size was 19.6 ± 7.7 mm. Depending on the length from the lower end of IJV to 2 cm below the lowest APV insertion (to assure direction of the APVs to the LA through the ASD and the margins of the ASD is covered by the stent), patients were divided into 3 groups >90 mm, 75-90 mm and <75 mm. Three stent sizes 90, 75, and 65 mm with specified dimensions derived from our data would treat all patients meeting the inclusion criteria.

Stents and sizes

VB Stent: Coated Nitinol stents are fabricated from laser cutting Nitinol tubing, heat setting them into the desired profile, and then electropolishing the frames. Radiopaque markers are swaged into the frames, which are then encapsulated using ePTFE membrane wraps that are heat sealed to the stent. The covered stent is available in 3 sizes that are all manufactured in a similar manner. Refer to drawings SH-07, SH- 08, and SH-09 for engineering details.

Stent deployment in 3D printed models

1. SUMMARY OF PRIMARY CLINICAL STUDY

To compassionate use, deployment of the device has been performed to date: One in Vietnam and one in India. Both cases were judged to be unsuitable for current devices or surgery. Both procedures were performed successfully with no residual shunt or device migration or any other complication. Patients are doing well following discharge the post procedural imaging with both Trans- Esophageal Echocardiogram (TEE) and CT/MRI shows excellent device profile and clinical progress.

Further data will be compiled with continued use of the device for compassionate use.