A Prospective Cohort Study Re-examining Tissue Oximetry Monitoring in Microsurgical Breast Reconstruction

Abstract

Background: The goal of inpatient monitoring after microsurgical breast reconstruction is to detect vascular compromise before flap loss. Near-infrared tissue oximetry (NITO) is commonly used for this purpose, but recent reports challenge its specificity and utility in current practice. Fifteen years after Keller published his initial study using this technology at our institution, we re-evaluate the role and limitations of this popular monitoring device.

Methods: A 1-year prospective study was performed for patients undergoing microsurgical breast reconstruction and monitored postoperatively using NITO. Alerts were evaluated, and clinical endpoints relating to an unplanned return to the operating room or flap loss were recorded.

Results: A total of 118 patients reconstructed with 225 flaps were included within the study. There were no cases of flap loss at the time of discharge. There were 71 alerts relating to a drop in oximetry saturation. Of these, 68 (95.8%) were deemed to be of no significance. In 3 cases (positive predictive value of 4.2%), the alert was significant, and there were concerning clinical signs apparent at that point. A sensor in an inframammary fold position was associated with nearly twice the average number of alerts as compared with areolar or periareolar positions ( P = 0.01). In 4 patients (3.4%), a breast hematoma required operative evacuation, and these cases were detected by nursing clinical examination.

Conclusions: The monitoring of free flaps after breast reconstruction through tissue oximetry shows a poor positive predictive value for flap compromise and requires clinical corroboration of alerts but missed no pedicle-related adverse events. With a high sensitivity for pedicle-related issues, NITO may be helpful postoperatively, but the exact timeframe for use must be weighed at the institutional level.