Improvement of sternal closure stability with reinforced steel wires.
BACKGROUND
Sternal dehiscence occurs when steel wires pull through sternal bone. This study tests the hypothesis that closure stability can be improved by jacketing sternal wires with stainless steel coils, which distribute the force exerted on the bone over a larger area.


METHODS
Midline sternotomies were performed in 6 human cadavers (4 male). Two sternal closure techniques were tested: (1) approximation with six interrupted wires, and (2) the same closure technique reinforced with 3.0-mm-diameter stainless steel coils that jacket wires at the lateral and posterior aspects of the sternum. Intrathoracic pressure was increased with an inflatable rubber bladder placed beneath the anterior chest wall, and sternal separation was measured by means of sonomicrometry crystals. In each trial, intrathoracic pressure was increased until 2.0 mm of motion was detected. Differences in displacement pressures between groups were examined at 0.25-mm intervals using the paired Student's t test.


RESULTS
The use of coil-reinforced closures produced significant improvement in sternal stability at all eight displacement levels examined (p < 0.03). Mean pressure required to cause displacement increased 140% (15.5 to 37.3 mm Hg) at 0.25 mm of separation, 103% (34.3 to 69.8 mm Hg) at 1.0 mm of separation, and 122% (46.8 to 103.8 mm Hg) at 2.0 mm of separation.


CONCLUSIONS
Reinforcement of sternal wires with stainless steel coils substantially improves stability of sternotomy closure in a human cadaver model.
McGregor
Walter E
WE
Cardiothoracic Research, Department of Cardiothoracic Surgery, Allegheny General Hospital, West Penn Allegheny Health System, Pittsburgh, Pennsylvania, USA.
Payne
Maryann
M
Trumble
Dennis R
DR
Farkas
Kathleen M
KM
Magovern
James A
JA
D000328:Adult; D001864:Bone Wires; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D013232:Steel; D013249:Sternum / Q000601:surgery*; D013536:Suture Techniques; D013718:Tensile Strength; D013908:Thoracotomy / Q000379:methods*; D014945:Wound Healing / Q000502:physiology
D013232:Steel