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

Abstract

Background: Postoperative monitoring after free functional gracilis transfer for smile reconstruction in long-standing facial paralysis is challenging as clinical assessments are limited. Objective: 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. Methods: 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. Results: 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. Conclusions: 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.