New, Virtually Wall-Less Cannulas Designed for Augmented Venous Drainage in Minimally Invasive Cardiac Surgery

Abstract

<jats:sec><jats:title>Objective</jats:title><jats:p> Inadequate venous drainage during minimally invasive cardiac surgery becomes most evident when the blood trapped in the pulmonary circulation floods the surgical field. The present study was designed to assess the in vivo performance of new, thinner, virtually wall-less, venous cannulas designed for augmented venous drainage in comparison to traditional thin-wall cannulas. </jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p> Remote cannulation was realized in 5 bovine experiments (74.0 ± 2.4 kg) with percutaneous venous access over the wire, serial dilation up to 18 F and insertion of either traditional 19 F thin wall, wire-wound cannulas, or through the same access channel, new, thinner, virtually wall-less, braided cannulas designed for augmented venous drainage. A standard minimal extracorporeal circuit set with a centrifugal pump and a hollow fiber membrane oxygenator, but no inline reservoir was used. One hundred fifty pairs of pump-flow and required pump inlet pressure values were recorded with calibrated pressure transducers and a flowmeter calibrated by a volumetric tank and timer at increasing pump speed from 1500 RPM to 3500 RPM (500-RPM increments). </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> Pump flow accounted for 1.73 ± 0.85 l/min for wall-less versus 1.17 ± 0.45 l/min for thin wall at 1500 RPM, 3.91 ± 0.86 versus 3.23 ± 0.66 at 2500 RPM, 5.82 ± 1.05 versus 4.96 ± 0.81 at 3500 RPM. Pump inlet pressure accounted for 9.6 ± 9.7 mm Hg versus 4.2 ± 18.8 mm Hg for 1500 RPM, −42.4 ± 26.7 versus −123 ± 51.1 at 2500 RPM, and −126.7 ± 55.3 versus −313 ±116.7 for 3500 RPM. </jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p> At the well-accepted pump inlet pressure of −80 mm Hg, the new, thinner, virtually wall-less, braided cannulas provide unmatched venous drainage in vivo. Early clinical analyses have confirmed these findings. </jats:p></jats:sec>

Anomalous left hepatic vein to coronary sinus in a patient with atrial septal defect: Minimally invasive approach; technical challenges

“…The right atrial cannula is clamped just before atriotomy and unclamped while taking the last few sutures over the right atrium. Other options to achieve adequate venous drainage are, kinetic assisted drainage or by employing new generation or virtually wall‐less cannulae 6,7 …”

Clinical Experience in Minimally Invasive Cardiac Surgery with Virtually Wall-Less Venous Cannulas

“…The performance of virtually wall-less venous cannulas designed for augmented venous drainage tested here in the clinical setting of MICS provided excellent flows at minimal vacuum levels and these findings confirm the performance increase over traditional thin wall cannulas previously demonstrated in vitro and in vivo. 9,10 It has been reported many times that traditional thin wall rectilinear cannulas have their limitations, [11][12][13] and in many cases, these limitations cannot be overcome. Inadequate peripheral venous drainage during MICS is a major headache, which can even be worsened by increased vacuum levels or increased centrifugal pump speed.…”

“…1), which prevents the caval axis from collapsing despite the negative pressure applied by the augmentation through the venous line. 9,10,16 Furthermore, the virtual absence of a cannula wall, which is a grid as shown in Figure 1, allows for direct venous drainage at all levels of affluent blood in the caval axis as depicted in Figure 4. This includes the ipsilateral internal iliac vein, the contra-lateral common iliac vein, the renal veins, the hepatic veins, the coronary sinus, as well as the superior vena cava and its affluents.…”

“…Traditional bench tests and more complex assessments using a collapsible vena cava substitute have shown promising performance of the new design, which were confirmed by in vivo experiments. [6][7][8][9][10] The present study was designed to assess the benefit of virtually wall-less venous cannulas designed for remote venous cannulation in combination with augmented venous drainage in the clinical setting of MICS.…”

New, optimized, dual-lumen cannula for veno-venous ECMO

“…17 As a matter of fact, a virtually wall-less cannula design 18 provided un-expected performance gains and, thus, was down-sized. 19,20 Lower suction requirements and/or higher flow also being key for portable and possibly implantable artificial lungs, the present study was designed to assess a new, optimized (with regard to the outer/inner lumen relationship as a result of the self-expanding properties) virtually wall-less, dual-lumen, bi-caval cannula for veno-venous ECMO in vivo.…”