PhysioSize your blood flow.
Optimising the lumen is the key to enhanced drainage. The space between the smartcanula and the vein wall is no longer a channel; instead, blood directly drains into the
smartcanula along its entire length. A shorter path at lower velocities leads to a
decreased pressure drop and increased flow.
The Concept
The smartcanula can be stretched over a mandrel and collapsed before intra-vascular insertion. In its “low-profile” configuration, the smartcanula is slid over a guidewire and positioned within the target vessel.
Once in position, the guide wire and the mandrel are removed. Due to its memory, the smartcanula expands and provides an unsurpassed lumen. Simple traction is enough for reduced diameter and removal.
Mathematical simulation of velocity contours for a standard 18F canula with a flow of 4 l/min by computational fluid dynamics (CFD): Pressure drop accounts for 140 mmHg.
For the same 18F access aperture and flow, CFD shows for an expanding design significantly lower velocity contours. Pressure drops in this setting account only for 49 mmHg.
Schematic craniocaudal view of the inferior vena cava, the iliac, and the femoral veins. At the target level, which is defined as the position providing optimal drainage, standard canulas use only a canula small fraction of the available cross-sectional area.
The diameter of a self-expanding canula is not limited by the diameter of the access vessel. As a result, drainage is superior and a pump or vacuum is not necessary for augmentation of venous return.
In vivo assessment of a standard canula within the inferior vena cava by intra-vascular ultrasound (IVUS=*). The luminal diameter of the standard accounts for 7.2 mm. The cross-sectional area accounts for 40.7 mm2 (a fraction of the vein).
The smartcanula in vivo as seen by IVUS* (same vena cava as shown above). The lumen of smartcanula is 10 mm and the cross-sectional area accounts for 78.5 mm2: almost double!