The Effect of Core Temperature on the Success of Free Tissue Transfer

ABSTRACT

During free tissue transfer, much effort is made to keep patients normothermic. It is feared that hypothermia, which is common in patients having such operations, can induce vasospasm leading to stasis and ultimately thrombogenesis. The present study was undertaken to determine the effect of core body temperature on the survival of free flaps in an animal model. Rats were anesthetized with inhaled isoflurane and randomly assigned to one of the following four core temperature groups: 34°C, 35°C, 37°C, and 39°C (n = 10 animals per group). Bilateral groin free flaps were then performed (n = 20 flaps per group) while each animal was maintained at the temperature of its assigned group. Flap survival was evaluated on postoperative day 5 by a blinded observer. The best flap survival occurred in the 34°C group, with an overall flap survival rate of 95%. There was a statistical difference between the survival rate of the combined 34°C and 35°C group (survival rate 90%, n = 40) and the combined 37°C and 39°C group (survival rate 67.5%, n = 40; p = 0.027). Hypothermia may have a beneficial effect on the success of free tissue transfer.

KEYWORDS

Core temperature - free tissue transfer - microsurgery - complication - flap failure

REFERENCES

• 1 Jones N F. Intraoperative and postoperative monitoring of microsurgical free tissue transfers.  Clin Plast Surg. 1992;  19 783-797
• 2 Salemark L. International survey of current microvascular practices in free tissue transfer and replantation surgery.  Microsurgery. 1991;  12 308-311
• 3 Serletti J M, Deuber M A, Guidera P M et al.. Atherosclerosis of the lower extremity and free-tissue reconstruction for limb salvage.  Plast Reconstr Surg. 1995;  96 1136-1144
• 4 Rieck B, Mailänder P, Machens H G. Vascular complications after free tissue transfer.  Microsurgery. 1995;  16 400-403
• 5 Flores-Maldonado A, Guzmán-Llanez Y, Castañeda-Zarate S et al.. Risk factors for mild intraoperative hypothermia.  Arch Med Res. 1997;  28 587-590
• 6 Bernthal E M. Inadvertent hypothermia prevention: the anaesthetic nurses' role.  Br J Nurs. 1999;  8 17-25
• 7 Johnston T D, Chen Y, Reed II R L. Functional equivalence of hypothermia to specific clotting factor deficiencies.  J Trauma. 1994;  37 413-417
• 8 Gubler K D, Gentilello L M, Hassantash S A, Maier R V. The impact of hypothermia on dilutional coagulopathy.  J Trauma. 1994;  36 847-851
• 9 Wolberg A S, Meng Z H, Monroe III D M, Hoffman M. A systematic evaluation of the effect of temperature on coagulation enzyme activity and platelet function.  J Trauma. 2004;  56 1221-1228
• 10 Hou S M, Seaber A V, Urbaniak J R. Relief of blood-induced arterial vasospasm by pharmacologic solutions.  J Reconstr Microsurg. 1987;  3 147-151
• 11 Puckett C L, Winters R R, Geter R K, Goebel D. Studies of pathologic vasoconstriction (vasospasm) in microvascular surgery.  J Hand Surg [Am]. 1985;  10 343-349
• 12 Seaber A V. Experimental vasospasm.  Microsurgery. 1987;  8 234-241
• 13 Fahmy H W, Moneim M S. The effect of prolonged blood stasis on a microarterial repair.  J Reconstr Microsurg. 1988;  4 139-143
• 14 Fernandez E J, Nadal R D, Gonzalez S M, Caffee H H. The effect of stasis on a microvascular anastomosis.  Microsurgery. 1983;  4 176-177
• 15 Zeeman B J, Morrison W A, O'Brien B M. Effect of stasis on the patency of microvenous grafts in avulsed rabbit femoral vessels.  Br J Plast Surg. 1985;  38 556-560
• 16 Defina J, Lincoln J. Prevalence of inadvertent hypothermia during the perioperative period: a quality assurance and performance improvement study.  J Perianesth Nurs. 1998;  13 229-235
• 17 Kurz A, Sessler D I, Lenhardt R. Perioperative normothermia to reduce the incidence of surgical-wound infection and shorten hospitalization.  N Engl J Med. 1996;  334 1209-1215
• 18 Lenhardt R, Marker E, Goll V et al.. Mild intraoperative hypothermia prolongs postanesthetic recovery.  Anesthesiology. 1997;  87 1318-1323
• 19 Mahoney C B, Odom J. Maintaining intraoperative normothermia: a meta-analysis of outcomes with costs.  AANA J. 1999;  67 155-163