title: The influence of hemostatic agents on bone healing after sternotomy in a porcine model.
abstract: BACKGROUND
  Sternotomy is the preferred access to the mediastinum. During sternotomy, trabecular bone is exposed, often resulting in bleeding, which can be treated with mechanical hemostatic agents; however, their influence on the healing process is relatively unexplored. The aim of this study was to investigate the influence of two hemostatic agents: bone wax (BW) and a water-soluble polymer wax, Ostene (WSW), on the mechanical and histologic characteristics of healing sternal bone.
  
  
  METHODS
  Twenty-four pigs underwent sternotomy and were randomized into three groups: WSW, BW, or no hemostatic treatment (control). Bone samples were obtained 6 weeks postoperatively.
  
  
  RESULTS
  Fracture strength (Fmax) and maximum stiffness (dF/dx) was lower in the BW group than in controls (Fmax: 175.2 vs. 255.8 N, dF/dx: 165.2 vs. 375.4 N/mm,) (p < 0.05). The stiffness did not differ statistically between the WSW and BW groups (298.4 vs 165.2 N/mm) nor did the fracture strength (211.4 vs 175.2 N). The fraction of granulomatous tissue was higher in the BW group compared with both the WSW group (79.1 vs. 16.52%) (p < 0.001) and controls (79.1 vs. 11.2%) (p < 0.001). There was more calcified tissue in controls than in the BW group (23.4 vs. 10.8%) (p < 0.05).
  
  
  CONCLUSIONS
  In a porcine model, BW significantly inhibited sternal healing and was associated with chronic inflammation and reduced mechanical integrity. The WSW did not, to the same degree as BW, inhibit bone healing and thus presents an alternative treatment option for sternal bleeding.
authors.affiliation: Department of Cardio-Thoracic and Vascular Surgery and Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark. Electronic address: rikke.vestergaard@ki.au.dk.
authors.forename: Rikke F
authors.initials: RF
authors.lastname: Vestergaard
authors.affiliation: Department of Biomedicine-Anatomy, Aarhus University, Aarhus, Denmark.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Brüel
authors.affiliation: Department of Biomedicine-Anatomy, Aarhus University, Aarhus, Denmark.
authors.forename: Jesper S
authors.initials: JS
authors.lastname: Thomsen
authors.affiliation: Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Hauge
authors.affiliation: Department of Orthopedic Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Kjeld
authors.initials: K
authors.lastname: Søballe
authors.affiliation: Department of Cardio-Thoracic and Vascular Surgery and Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Hasenkam
mesh_terms: D000818:Animals; D005260:Female; D006490:Hemostatics / Q000494:pharmacology*; D023421:Models, Animal; D010168:Palmitates / Q000494:pharmacology*; D020442:Poloxamer / Q000494:pharmacology*; D056346:Sternotomy; D013552:Swine; D014885:Waxes / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D006490:Hemostatics; C512681:Ostene; D010168:Palmitates; D014885:Waxes; D020442:Poloxamer; C055480:bone wax