Profound Hypothermic Cardiopulmonary Bypass Facilitates Survival Without a High Complication Rate in a Swine Model of Complex Vascular, Splenic, and Colon Injuries
Abstract presented at the American College of Surgeons 92nd Annual Clinical Congress, Surgical Forum, Chicago, IL, October 2006.
Received 20 October 2006; received in revised form 8 December 2006; accepted 8 January 2007. published online 05 March 2007.
Background
Induction of a profound hypothermia for emergency preservation and resuscitation in severe hemorrhagic shock can improve survival from lethal injuries, but the impact of hypothermia on bleeding and infectious complications has not been completely determined.
Study Design
Uncontrolled hemorrhage was induced in 26 swine (95 to 135 lbs) by creating an iliac artery and vein injury, and 30 minutes later, by lacerating the descending thoracic aorta. Through a left thoracotomy approach, profound total body hypothermia (10° C) was induced (2° C/min) by infusing cold organ preservation solution into the aorta. The experimental groups were: vascular injuries alone (group 1, n=10), vascular and colon injuries (group 2, n=8), and vascular, colon, and splenic injuries (group 3, n=8). All injuries were repaired during 60 minutes of low-flow cardiopulmonary bypass (CPB) with hemodilution and profound hypothermia; then the animals were slowly rewarmed (0.5° C/min) back to normothermia. Survivors were monitored for 6 weeks for postoperative bleeding, neurologic deficits, cognitive function (learning new skills), organ dysfunction, and septic complications.
Results
Six-week survival rates were 90% in group 1, 87.5% in group 2, and 75% in group 3 (p > 0.05). One animal in each group died from acute cardiac failure during the early postoperative phase. Splenic salvage was possible in all animals, and none required complete splenectomy for hemorrhage control. All surviving animals were neurologically intact, displayed normal learning capacity, and had no longterm organ dysfunction. None of the animals had postoperative hemorrhage or experienced septic complications. One animal in group 3 died on the ninth postoperative day because of bowel obstruction (volvulus).
Conclusions
Induction of profound hypothermia can preserve the viability of key organs during repair of lethal injuries. This strategy can be used even in the presence of solid organ and bowel injuries to improve survival, without any considerable increase in postoperative complication rates.
⁎Division of Trauma, Emergency Surgery and Surgical Critical Care, Massachusetts General Hospital/Harvard Medical School, Boston, MA
†Departments of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD
Correspondence address: Hasan B Alam, MD, FACS, Division of Trauma, Emergency Surgery and Surgical Critical Care, Massachusetts General Hospital, 165 Cambridge St, Suite 810, Boston, MA 02114.
Competing Interests Declared: None.
Funded by the National Institutes of Health Grant R01 HL71698 (PI: Alam).
ABSTRACT