P019: ASSOCIATION OF INTRAOPERATIVE HYPOTENSION AND VASOPRESSOR USE WITH COMPLICATIONS OF FREE TISSUE TRANSFER SURGERY
Paul P Potnuru, MD1, Roxanna Rasekhi, DO2, Charles A Karcutskie, IV, MD, MA1, Christian Diez, MD, MBA1, Roman Dudaryk, MD1; 1University of Miami School of Medicine, 2Jackson Memorial Hospital
Introduction: Intraoperative hypotension is considered to be a risk factor for flap-related complications in free tissue transfer surgery. However, vasopressor administration in the anesthetic management of free tissue transfer surgery remains controversial because of animal data showing decreased flap perfusion with vasopressor administration. The objective of this study was to examine the association of intraoperative hypotension and vasopressor use with flap-related complications.
Methods: A retrospective chart review of 244 adult patients undergoing free tissue transfer surgery was performed. Flap-related complications were defined as follows: unplanned reoperation, hematoma, pharyngocutaneous fistula, flap failure, flap dehiscence, and/or flap thrombosis. Intraoperative hypotension was defined as ≥ 1 episode of mean arterial pressure (MAP) ≤ 60 mmHg for 15 minutes. Vasopressor use was defined as administration of either phenylephrine or ephedrine. Categorical data was analyzed using a Chi-squared test. Continuous variables were analyzed with Student’s t-test. Significance was set at p ≤ 0.05.
Results: Free tissue transfer surgery was performed on 244 patients, with a total of 251 flaps. Types of flaps were as follows: 65.7% head and neck, 31.9% extremity, 1.2% breast, 0.8% trunk, and 0.4% other. Flap-related complications occurred in 54 patients (21.5%). Thirty-two patients (13.1%) had an unplanned reoperation. Hematoma occurred in 12 patients (4.8%), flap failure in 20 patients (8%), flap dehiscence in 13 patients (5.2%), flap thrombosis in 11 patients (4.5%), and pharyngocutaneous fistula in 6 patients (2.4%). There were no differences in age, body mass index, diabetes, hypertension, smoking status, transfusion status (pre-, intra-, and postoperative), flap location, or postoperative hemoglobin level between those with and without flap-related complications (all p > 0.05). (Fig. 1)
Hypotension occurred in 66 cases (26.3%). Vasopressors were administered in 168 cases (66.9%): phenylephrine in 119 cases (47.4%), and ephedrine in 126 cases (50.2%). There was no significant association between hypotension and flap-related complications (22.7% hypotension, 18.2% no hypotension, P = 0.443). Likewise, there was no statistically significant association between flap-related complications and the use of ephedrine (22.2% ephedrine, 20.8% no ephedrine, P = 0.784) or phenylephrine (18.5% phenylephrine, 24.2% no phenylephrine, P = 0.268). (Fig. 2)
Conclusions: Our data suggest the occurrence of hypotension during free tissue transfer surgery was not associated with increased risk of flap-related complications. Moreover, the intraoperative use of phenylephrine and ephedrine does not appear to adversely impact clinical outcomes in free tissue transfer surgery. The generalizability of this study is also limited by its retrospective nature. In this study, we did not examine the timing or dosage of vasopressor administration. Further prospective studies examining the impact of hypotension and vasopressor use, controlled for the timing of administration and dosage, on flap-related complications should provide more definitive evidence. Until then, the judicious use of intraoperative vasopressors guided by careful clinical judgment is suggested during free tissue transfer surgery.