New bench test for venous cannula performance assessment

Abstract

Cannula design is of prime importance for venous drainage during cardiopulmonary bypass (CPB). To evaluate cannulas intended for CPB, an in vitro circuit was set up with silicone tubing between the test cannula encased in a movable preload reservoir and another static reservoir. The pressure-drop (ΔP) value (P-drainage – P-preload) was measured using Millar pressure transducers. Flow rate (Q) was measured using an ultrasound flowmeter. Data display and data recording were controlled using a LabView application, custom made particularly for our experiments. Our results demonstrated that ΔP, Q, and cannula resistance (ΔP/Q) values were significantly decreased when the cannula diameter was increased for Smart and Medtronic cannulas. Smartcanula® showed 36% and 43% less resistance compared to Medtronic venous and Medtronic femoral cannulas, respectively. The cannula shape (straight- or curved-tips) did not affect the DLP cannula resistance. Out of five cannulas tested, the Smartcanula® outperforms the other commercially available cannulas. The mean (ΔP/Q) values were 3.3 ± 0.08, 4.07 ± 0.08, 5.58 ± 0.10, 5.74 ± 0.15, and 6.45 ± 0.15 for Smart, Medtronic, Edwards, Sarns, and Gambro cannulas, respectively (two-way ANOVA, p < 0.0001). In conclusion, the present assay allows discrimination between different forms of cannula with high or low lumen resistance.

Keywords

Cardiopulmonary bypass cannulas venous drainage flow rate lumen resistance

Get full access to this article

View all access options for this article.

References

1 Trusler GA . Venous cannulas for cardiopulmonary bypass. Am J Surg 1965; 110: 1001–1002.

2 Bugge M Lepore V Dahlin A . The “908 bent” two-stage venous cannula. Eur J Cardiothorac Surg 1995; 9: 526–527.

3 Lawrence DR Desai JB . Forty-five degree two-stage venous cannula: advantages over standard two-stage venous cannulation. Ann Thorac Surg 1997; 63: 253–254.

4 Phillips SJ Romanowski E . A newly designed venous cannula for cardiopulmonary bypass. J Thorac Cardiovasc Surg 1972; 63: 769–770.

5 von Segesser LK . Cardiopulmonary support and extracorporeal membrane oxygenation for cardiac assist. Ann Thorac Surg 1999; 68: 672–677.

6 Ni YM Leskosek B Shi LP . Optimization of venous tubing diameter for cardiopulmonary bypass. Eur J Cardiothorac Surg 2001; 20: 614–620.

7 Jegger D Mueller X Mucciolo G . A new expandable cannula to increase venous return during peripheral access cardiopulmonary bypass surgery. Int J Artif Organs 2002; 25: 136–140.

8 Mueller XM Tevaearai HT Jegger D Horisberger J Mucciolo G von Segesser LK . A new expandable venous cannula for minimal access heart surgery. Ann Thorac Surg 2002; 74: S1330–S1333.

9 Jegger D Tevaearai HT Horisberger J . Augmented venous return for minimally invasive open heart surgery with selective caval cannulation. EJCTS 1999; 16: 312–316.

10.

10 von Segesser LK; . Peripheral cannulation for cardiopulmonary bypass. Multimedia Manual of Cardiothoracic Surgery (October 9, 2006). doi: 10.1510/mmcts.2005.001610.