Document Detail

Characterizing the impact of minor cannula design modification.
MedLine Citation:
PMID:  22388942     Owner:  NLM     Status:  Publisher    
Objective: Bench evaluation of the hydrodynamic behavior of venous cannulas is a valuable technique for the analysis of their performance during cardiopulmonary bypass (CPB). The aim of this study was to investigate the effect of the internal diameter of the extracorporeal connecting tube of venous cannulas on flow rate (Q), pressure drop (?P), and cannula resistance (?P/Q2) values, using a computer assisted test bench.?Methods: An in vitro circuit was set up with silicone tubing between the test cannula encased in a movable reservoir, and a static reservoir. The ?P, defined as the difference between the drainage pressure and the preload pressure, was measured using high-fidelity Millar pressure transducers. Q was measured using an ultrasonic flowmeter. Data display and data recording were controlled using virtual instruments in a stepwise fashion.?Results: The 27 F smartcanula® with a 9 mm connecting tube diameter showed 17% less resistance compared to that with an 8 mm connecting tube diameter. Q values were 7.22±0.1 and 7.81±0.04 L/min for cannulas with 8 mm and 9 mm connecting tube diameters, respectively. The ?P/Q2 ratio values were 72% lower for the Medtronic cannula with a 9 mm connecting tube diameter compared to that with an 8 mm connecting tube diameter. Q values for the Medtronic cannula were 3.94±0.23 and 6.58±0.04 L/min with 8 mm and 9 mm connecting tube diameters, respectively. The 27 F smartcanula® showed 13% more flow rate compared to the 28 F Medtronic cannula using the unpaired Student t-test (p<0.0001).?Conclusions: Our results demonstrated that Q was increased but ?P and ?P/Q2 values were significantly decreased when the connecting tube diameter was increased for venous cannulas. The connecting tube diameter significantly affected the resistance to liquid flow through the cannula. Smartcanulas® outperform Medtronic cannulas.
Saad Abdel-Sayed; Julien Favre; Ludwig K von Segesser
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-2-27
Journal Detail:
Title:  The International journal of artificial organs     Volume:  -     ISSN:  1724-6040     ISO Abbreviation:  -     Publication Date:  2012 Feb 
Date Detail:
Created Date:  2012-3-5     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7802649     Medline TA:  Int J Artif Organs     Country:  -    
Other Details:
Languages:  ENG     Pagination:  0     Citation Subset:  -    
Department of Cardio-Vascular Surgery, University Hospital CHUV, Lausanne - Switzerland.
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