Implantable Doppler Ultrasound Monitoring in Head and Neck Free Flaps: Balancing the Pros and Cons.

Objectives/hypothesis: Free flap transfer offers a versatile option for reconstruction in head and neck surgery, with success rates over 95%. There remains a substantial re-exploration rate of roughly 5% to 15%, with early recognition of compromise essential to flap survival. Monitoring techniques are highly desirable, with the gold standard being clinical monitoring. The Cook-Swartz Doppler (CSD) probe utilizes Doppler technology to inform clinicians about real-time flow. We aim to describe our adoption of this technology in 100 consecutive free flaps.
Study Design: Prospective case series.
Methods: Prospective data were collected from July 2014 to June 2015 on 100 consecutive free flaps performed at a head and neck unit in London, Ontario. All patients had a CSD inserted for arterial and venous monitoring.
Results: A total of 100 free flaps were performed on 99 patients. Sensitivity was 87.1% and specificity was 85.7%. Positive predictive value was 98.8% and negative predictive value was 33.3%. False-negative and false-positive rate were 1.0% and 12.0%, respectively. The exploration rate was 12%, with no flap loss and two partial debridements. The CSD was helpful in management in 9% of cases and was clinically unhelpful in 11% of cases, with 10 of 11 abnormal signals ignored. There were three unique CSD complications; one retained wire, one pedicle laceration during extraction, and one clot around the probe interrupting signal.
Conclusions: The CSD is a helpful adjunct to clinical monitoring but has unique complications, which were not previously described. Pros and cons must be considered for new centers adopting this technology.
Level of Evidence: 4 Laryngoscope, 131:E1854-E1859, 2021.
(© 2021 American Laryngological, Rhinological and Otological Society Inc, "The Triological Society" and American Laryngological Association (ALA).)