Initial experience with personal digital assistant-based reflectance photoplethysmograph for free tissue transfer monitoring

Abstract

Improved microsurgical technique has resulted in a high percentage of successful free tissue transfers. When a tissue transfer fails in the head and neck, however, the results are orocutaneous fistulas, carotid artery exposure, and deformity that adds morbidity, expense, and may delay adjuvant therapy. Postoperative monitoring of tissue perfusion can detect early problems in free tissue transfer that may allow for early intervention and salvage. The authors have demonstrated that reflectance photoplethysmography can detect perfusion changes in free tissue transfer within 5 minutes of a pedicle "insult" intraoperatively. Normative data for viable flaps from various donor sites have been established. The authors now report their initial experience with a newly developed reflectance photoplethysmograph based on a hand-held computer for routine clinical use. Their results are compared with a conventional surveillance protocol that included observation, bleeding to pin prick, and bedside duplex scanning of the vascular pedicle. In a series of 30 free tissue transfers (29 patients), there was one ischemic event (skin paddle loss only), which was detected by the monitor. The monitor was able to predict correctly (one flap) survival of a free tissue transfer even when duplex ultrasonic data were indicative of an absence of perfusion. Personal digital assistant-based photoplethysmography appears to be a promising device for bedside diagnosis of free tissue transfer viability or ischemia.