title: A sheep model for thoracic aortic surgery in the presence of systemic coagulopathy.
abstract: Surgical repair of aneurysms, traumatic injuries, or congenital anomalies of the thoracic aorta are associated with high morbidity and mortality mainly as a result of excessive and uncontrollable hemorrhage from diffuse coagulopathy. We developed a model in sheep that simulates this coagulopathic state for experimentation with thoracic aorta surgery. This experimental animal model involves administering a 600-mg aspirin suppository once a day for the 2 days preceding surgery and a final dose on-call to surgery. Prior to cross-clamping the aorta, an intravenous (i.v.) bolus of heparin (400 IU/kg) was administered. Thirty minutes later, the i.v. heparin bolus was repeated. Pre- and intraoperative activated clotting time was 101 +/- 10 s and >1500 s (p < .0001); prothrombin time, 21 +/- 1 s and >100 s (p < .0001); and activated partial thromboplastin time, 20 +/- 1 s and >50 s (p < .0001), respectively. We utilized a partial cross-clamp-and-sew technique to anastomose a woven, gelatin-impregnated, 16-mm tube graft end-to-side to the descending thoracic aorta. Mean total blood loss was 1367 +/- 282 mL, which included mean blood loss from time of release of aortic cross-clamp to close (422 +/- 135 mL) and mean total blood output from chest tube drain (945 +/- 203 mL). The mean time to achieve hemostasis at suture lines after aortic cross-clamp release was 15.5 +/- 6.6 min. In conclusion, a sheep model with induced coagulation defects was successfully developed and reproducible for experimentation involving thoracic aortic surgery.
authors.affiliation: Department of Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Cooper Hospital/University Medical Center, Camden, USA.
authors.forename: H S
authors.initials: HS
authors.lastname: Tran
authors.forename: F A
authors.initials: FA
authors.lastname: Chrzanowski
authors.forename: M M
authors.initials: MM
authors.lastname: Puc
authors.forename: S W
authors.initials: SW
authors.lastname: Marra
authors.forename: J H
authors.initials: JH
authors.lastname: Cilley
authors.forename: D
authors.initials: D
authors.lastname: Malli
authors.forename: N
authors.initials: N
authors.lastname: Patel
authors.forename: C W
authors.initials: CW
authors.lastname: Hewitt
authors.forename: A J
authors.initials: AJ
authors.lastname: DelRossi
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D000925:Anticoagulants; D001013:Aorta, Thoracic / Q000601:surgery*; D001778:Blood Coagulation Disorders / Q000503:physiopathology*; D016063:Blood Loss, Surgical; D004195:Disease Models, Animal; D006493:Heparin; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D012756:Sheep; D013525:Surgical Instruments
chemical_list: D000925:Anticoagulants; D006493:Heparin