Ann Thorac Surg 2003;75:1065
© 2003 The Society of Thoracic Surgeons
Correspondence
Which is the best sternotomy closure technique?
Julian E. Losanoff, MDa,
Bruce W. Richman, MAa,
James W. Jones, MD, PhDa,
Andrea D. Collier, MScb
a Department of Surgery, University of Missouri-Columbia, School of Medicine, M580 Health Sciences Center, One Hospital Dr, Columbia, MO 65212, USA
b 3905 Olympic Ct. Columbia, MO 65202, USA
e-mail: jonesjw{at}health.missouri.edu
To the Editor:
We read with interest the recent article by Cohen and Griffin on biomechanical comparison of sternotomy closure techniques [1]. The authors compared peristernal figure-eight wires, figure-eight cables, and PectoFix Dynamic Sternal Fixation (DSF) plates under constant tension. Cohen and Griffin’s experimental model and results are similar to those shown at the Pectofix web site [2], indicating DSF’s superiority in stiffness and yield load. The biomechanical basis of DSF’s effectiveness is based on force distribution over a larger area, resulting in lower sternal stress [2]. This principle has been established in earlier sternotomy closure studies utilizing wires [3] and cables [4] threaded through sternal grommets, important biomechanical research articles not cited in the Cohen and Griffin article. Their experimental model included figure-eight peristernal closures and constantly increasing tension which might not approximate actual physiologic strain. Their article does not assess transsternal cerclage wire, among the most widely used closure methods [5], nor repetitive cycling loading, a realistic replication of the forces associated with breathing, coughing, and bodily movement which cause wire to cut through the bone [5]. The wiring system used by Cohen and Griffin might respond differently if tested under repetitive variable force cycling loads. Our ongoing sternotomy closure study uses fresh cadaveric sterna attached to a biomechanical testing device (TAHDi Texture Analyzer, Texture Technologies Corp, Scarsdale, NY). Various sternotomy repair techniques utilizing #5 cerclage wire (Ethicon Somerville, NJ), including transsternal, peristernal, and pericostal single and figure-eight closures, are tested at repetitive cyclic loads at both 400 and 800 Newtons and speeds of 0.04 mm/sec and 0.5 mm/sec. The preliminary results of sternotomy closure’s failure testing (wire cutting through bone) shows striking differences in sternal displacement associated with particular closure methods and variable forces and speeds. Despite some questions about their biomechanical model’s design and relationship to earlier sternotomy research studies, Cohen and Griffin’s results suggest superiority of both the DSF system and cables over cerclage wires.
References
- Cohen D.J., Griffin L.V. A biomechanical comparison of three sternotomy closure techniques. Ann Thorac Surg 2002;73:563-568.[Abstract/Free Full Text]
- PectoFix, Inc. (South Plainfield, NJ). Dynamic sternal fixation (DSF) of the sternum. http://www.pectofix.com
- Labitzke R., Schramm G., Witzel U., Quisthout P. "Sleeve-rope closure" of the median sternotomy after open heart operations. Thorac Cardiovasc Surg 1983;31:127-128.[Medline]
- Hale JE, Anderson DD, Johnson GA, Magovern JA. An assessment of the pull-through strength and fatigue properties of a new sternal closure technique. Twenty-third Annual Meeting of the American Society of Biomechanics, University of Pittsburgh, October 21–23, 1999 (http://asb-biomech.org/abstracts99/134/)
- Casha A.R., Gauci M., Yang L., Saleh M., Kay P.H., Cooper G.J. Fatigue testing median sternotomy closures. Eur J Cardiothorac Surg 2001;19:249-253.[Abstract/Free Full Text]
