An Analysis of the Implantable Doppler Probe for Postoperative Free-Flap Monitoring and Risk Factor Analysis for Revision Surgery in Facial Reanimation Surgery.

Postoperative monitoring after free functional gracilis transfer for smile reconstruction in long-standing facial paralysis is challenging as clinical assessments are limited. In patients receiving free gracilis transfer for smile reconstruction, we compared the implantable Doppler probe with a handheld Doppler/intraoperative blood flow regarding the reliability in detecting perfusion compromised free flaps. In a retrospective cohort study we analyzed facial paralysis patients who, after free functional smile reconstruction, were postoperatively monitored using the implantable Doppler probe. Furthermore, we conducted a multiple logistic regression analysis on risk factors for vascular complications. We included 119 patients who received 125 free functional gracilis transfers. The sensitivity of the implanted Doppler probe was 1.0 and the specificity 0.88. There were no false-negative results (negative predictive value = 1.0). The calculated positive predictive value was 0.41. We used a handheld Doppler device to verify signal changes. The combined positive predictive value of both tests was 0.91. Previous surgery in the surgical field was a risk factor for impaired blood flow. The implantable Doppler probe proved to be a reliable tool for postoperative monitoring of free functional gracilis transfer in facial reanimation surgery. Special care should be taken in preoperated patients.