Abstract
Background Transcutaneous tissue oximetry is widely used as an adjunct for postoperative monitoring
after microvascular breast reconstruction. Despite a high sensitivity at detecting
vascular issues, alarms from probe malfunctions/errors can generate unnecessary nursing
calls, concerns, and evaluations. The purpose of this study is to analyze the false
positive rate of transcutaneous tissue oximetry monitoring over the postoperative
period and assess changes in its utility over time.
Methods Consecutive patients undergoing microvascular breast reconstruction at our institution
with monitoring using transcutaneous tissue oximetry were assessed between 2017 and
2019. Variables of interest were transcutaneous tissue oximetry alarms, flap loss,
re-exploration, and salvage rates.
Results The study included 175 patients (286 flaps). The flap loss rate was 1.0% (3/286).
Twelve patients (6.8%) required re-exploration, with 9 patients found to have actual
flap compromise (all within 24 hours). The salvage rate was 67.0%. The 3 takebacks
after 24 hours were for bleeding concerns rather than anastomotic problems. Within
the initial 24-hour postoperative period, 43 tissue oximetry alarms triggered nursing
calls; 7 alarms (16.2%) were confirmed to be for flap issues secondary to vascular
compromise. After 24 hours, none of the 44 alarms were associated with flap compromise.
The false positive rate within 24 hours was 83.7% (36/43) compared with 100% (44/44)
after 24 hours (p = 0.01).
Conclusion The transcutaneous tissue oximetry false positive rate significantly rises after
24 hours. The benefit may not outweigh the concerns, labor, and effort that results
from alarms after postoperative day 1. We recommend considering discontinuing this
monitoring after 24 hours.
Keywords
monitoring - ViOptix - tissue oximetry - breast reconstruction
