Intraoperative Management of Free Flaps

Abstract

Intraoperative management of hemodynamic instability during microvascular flap reconstruction is often based on anecdotal experience. Randomized controlled trials are difficult to perform when overall success rates are high. This study seeks to determine current practices for management of intraoperative hypotension during microsurgical free tissue transfer. An anonymous, 17-question, multiple choice, and open response online survey was distributed to university surgeons identified from the American Society of Plastic Surgeons and American Society of Reconstructive Microsurgeons online membership listing. Responses were collected from April 1, 2012, to May 1, 2012. Questions included number of years of microsurgery experience, number of flaps performed yearly, acceptable lower limits of blood pressure, preferences for treatment of hypotension, intraoperative conditions (hemodilution, temperature, and regional anesthesia), preferred methods of postoperative flap monitoring, and timing/method of prophylaxis of thromboembolic complications. Anonymous responses were analyzed individually as well as per respondent's experience. The response rate was 26.7% (145/544), with 88.3% performing microsurgery. Sixty-two percent performed 24 or less free flaps per year (low volume). Thirty-seven percent performed greater than 24 per year (high volume). The acceptable lower limit (SD) of systolic blood pressure was 92.6 (11.3) mm Hg for the low-volume group and 86.9 (16.2) for the high volume group (P = 0.035). The treatment of choice for hypotension was fluid administration (94.5%). Vasopressors were used by 50.0% of low-volume respondents and 38.1% of high-volume respondents (P = 0.312). Twenty-two respondents (23.2%) stated they had a flap loss due to administration of vasopressors. There was no significant difference between high- and low-volume surgeons' responses. A national survey of microsurgeons demonstrates that many would not use vasopressors to treat intraoperative hypotension regardless of their experience. Although subject to responder bias, this report, nevertheless, outlines current practice. The need to develop a scientific basis for these practices is evident.