The most commonly selected retrieval device for an occluder is a snare catheter. Single-loop catheters are often used, but multiple-loop snares are excellent options, increasing the probability of capture (Fig. 41.2). The target is the device hub or attachment pin. Capturing the central part (stent) of an atrial occluder device with a snare will make it impossible to retrieve into a sheath.

The sheath selected for retrieval of an occluder device should be at least 2 Fr larger than the size of the original delivery sheath. When retrieving large atrial septal defect occluders, it can be useful to bevel the tip of the sheath at 30–40°, before introducing and advancing the system. The beveling technique is generally only applicable to non-armored sheaths such as the Cook Mullins Check-Flo. The main purpose of beveling is to provide a wider profile of the sheath to retrieve the snared hub of a large device. The best alignment for pulling the snared device into the beveled sheath is obtained by rotating the sheath or the snared device, so that the free end of the snared hub is aligned with the most proximal part of the beveled tip (Fig. 41.3). A beveled tip is sharp and so can potentially cause damage to the vascular and cardiac structures, so care must be taken when advancing the sheath without the protection of a dilator or a coaxial catheter.

In some cases, it is useful to position a super stiff guidewire adjacent or beyond the embolized device, stabilizing the sheath during capture and reducing the risk of trauma. The guidewire should be removed after capture, before retrieval of the device into the sheath.