CANINE MUSCULAR VSD DEVICE

IMPORTANT: Device Selection is based on the balloon measured diameter of the defect (i.e., a 10 mm defect will require a 10 mm device).

Device Size (Diameter of Waist)	Device Size (Length)	Minimum Recommended Sheath Size (TorqVue® Delivery System)
4 mm	7 mm	5 French, 180º Curve
4 mm	7 mm	6 French, 45º Curve
6 mm	7 mm	6 French, 45º or 180º Curve
8 mm	7 mm	6 French, 45º or 180º Curve
10 mm	7 mm	6 French, 45º or 180º Curve
12 mm	7 mm	7 French, 45º or 180º Curve
14 mm	7 mm	8 French, 45º or 180º Curve
16 mm	7 mm	8 French, 45º or 180º Curve
18 mm	7 mm	9 French, 45º or 180º Curve

Step-by-step Procedural Overview

The Canine Muscular VSD Device is implanted percutaneously by catheter technique (right-or left-sided approach). The approach depends on the location of the muscular ventricular septal defect. Generally, defects in the upper portion of the septum can be approached from the femoral vein, whereas low defects may be easier to close with a transjugular approach.

Catheter Technique

1. Perform procedure under either general or conscious sedation.
   
   
2. Give patient a dose of an appropriate antibiotic during the catheterization procedure.
   
   
3. Obtain access in the femoral artery, femoral vein, and/or right internal jugular vein.
   
   
4. Administer heparin to achieve an activated clotting time of greater than 200 seconds throughout the procedure.
   
   
5. Perform routine right and left heart catheterization. Assess the pulmonary vascular resistance.
   
   
6. Perform angiography to define the location, size, and number of VSD(s).
   
   
7. Use transesophageal echocardiography (TEE) to provide additional imaging of the VSD(s) and to assist with delivery system and device placement.
   
   
8. Select a device up to 2 mm larger than the VSD(s) size as assessed by TEE or angiography at end-diastole (the bigger of the two diameters).
   
   
9. Access the VSD(s) with a guidewire using either venous (Figure 1) or arterial approach (Figure 2). The venous approach may be from either the inferior vena cava or the superior vena cava (arteriovenous loop) depending on the location of the VSD.
   
   Figure 1: Right-Sided Approach
   
   Figure 2: Left-Sided Approach
   
   
10. Advance the delivery sheath and dilator over the guidewire until the tip of the dilator crosses the VSD.
    
    
11. Remove the dilator.
    
    
12. Advance the guidewire into the apex of the ventricle and position the tip of the delivery sheath in the body of the ventricle.
    
    
13. Pass the delivery cable through the loader and attach the Canine Muscular VSD Device to the tip of the delivery cable by rotating the device counterclockwise until secure. To ensure proper occluder release, rotate the device counter-clockwise 1/8 of a turn.
    
    
14. Immerse the device and loader in saline solution and retract the device into the loader.
    
    
15. Slowly remove the guidewire and allow for back-bleeding to purge air from the system.
    
    
16. Connect the loader to the delivery sheath.
    
    
17. Transfer the device from the loader into the delivery sheath, and without rotation, advance the device to the tip of the delivery sheath.
    
    
18. Use TEE and angiography as a guide during each step of device deployment.
    
    
19. Retract the delivery sheath slowly until the distal disc is deployed.
    
    
20. Pull the entire assembly (delivery cable and delivery sheath) into the VSD.
    
    
21. Retract the sheath to deploy the waist of the device in the defect.
    
    
22. Once position is confirmed, retract the sheath to deploy the proximal disc.
    
    
23. If the position of the device is unsatisfactory:
    
    
    1. Stabilize the delivery cable and re-advance the delivery sheath until the device is completely within the sheath.
       
       
    2. Reposition the device and deploy it again, or remove the device from the patient.
    
    
    
24. If the device position is satisfactory:
    
    
    1. Attach the plastic vise to the delivery cable, then release the device by rotating the delivery cable counter-clockwise until it separates from the device.
       
       
    2. Retract the delivery cable into the delivery sheath.
       
       
    3. Remove the delivery cable and delivery sheath from the patient.
    
    
    
25. Complete a TEE evaluation to confirm device placement, assess for residual shunting, obstruction or regurgitation induced by the device.
    
    
26. Perform an angiogram to assess for residual flow through the device.
    
    
27. Give the patient two doses of an appropriate antibiotic post-catheterization procedure at eight hour intervals.
    
    Figure 3: Placement of Canine Muscular VSD Device