Temporary caval stenting improves venous drainage during cardiopulmonary bypass

¹ CHUV, Lausanne, Switzerland

^* To whom correspondence should be addressed. E-mail: editor{at}ejcts.ch.

	Abstract

Objectives: Assess the benefit of temporary caval stenting for remote venous drainage during cardiopulmonary bypass (CPB). Methods: Temporary caval stenting was realized in bovine experiments (65±6 kg) by the means of self-expanding (18F for insertion, 36F in situ) venous cannulas (Smartcanula LLC, Lausanne, Switzerland) with various lengths: 43 cm, 53 cm, 63 cm versus a standard 28F wire armed cannula in trans-jugular fashion. Maximal blood flows were assessed for 20, 25 and 30 mmHg of driving pressure with a motorized table height adjustment system. In addition the inferior caval diameters (just above its bifurcation) were measured in real time with intra-vascular ultrasound (IVUS). Results: Venous drainage (flow in l/min) at 20 mmHg, 25 mmHg, and 30 mmHg drainage load was 3.5±0.5, 3.7±0.7, and 4.0±0.6 for the 28F standard versus 4.1±0.7, 4.0±1.3, and 3.9±1.1 for the 36F smart 43 cm, versus 5.0±0.7, 5.3±1.3, and 5.4±1.4 for the 36F smart 53 cm, versus 5.2±0.5*, 5.6±1.1*, and 5.8±1.0* for the 36F smart 63 cm. The inferior vena caval diameters at 30 mmHg were 13.5±4.8 mm for 28F standard, 11.1±3.6 36F smart 43 cm, 11.3±3.2 for 36F 53 cm, and 17.0±0.1* for 36F 63 cm (*p<0.05 for 28F standard versus 36F smart 63 cm long). Conclusions: The 43 cm self-expanding 36F smartcanula® outperforms the 28F standard wire armed cannula at low drainage pressures and without augmentation. Temporary caval stenting with long self-expanding venous cannulas provides even better drainage (+51%). Keywords: Cardiopulmonary bypass; Venous drainage; Venous cannula; Cannulation; Pump oxygenator; Stent