Green Light Photoplethysmography Monitoring of Free Flaps

Abstract
MICROVASCULAR free tissue transfer has emerged as the standard of care for reconstruction of complex head and neck and skull base defects after trauma or oncologic ablative surgery. Success rates have steadily improved to a level of 95% or greater in most series.1 A critical factor in achieving a high rate of flap survival is the monitoring of the free tissue transfer after reimplantation to detect any changes that might indicate ischemia. The time interval for reestablishing vascular patency, however, is limited by the no-reflow phenomenon.2 It does not exceed 8 to 12 hours based on animal studies and clinical observation.3 Prompt reoperation and correction of the microvascular obstruction are necessary to maintain flap viability. Revision is usually successful during this early critical period.4,5