Open Collections

Abstract

Free tissue transfer (FTT) is a microsurgical procedure involving harvesting tissue from one part of the body and transplanting it to a traumatic defect or surgically created wound after tumor removal or trauma. This surgery requires connecting the blood vessels of the harvested tissue (flap) to the recipient site on the head and neck. Vascular complications can lead to FTT failure. Early detection of vascular compromise is crucial for successful salvage. Near-infrared spectroscopy (NIRS) offers continuous, non-invasive monitoring of FTT hemodynamics and tissue oxygenation, which reflect tissue vitality. However, no commercially available NIRS systems feature a sensor probe small enough for real-time continuous monitoring in the head and neck region. Our research team developed a second version of the NIRS system (V2) for this purpose. This study aimed to obtain post-operative NIRS measurements from patients undergoing FTT for head and neck reconstruction and to assess patient and clinician experiences with this novel monitoring method. Following safety evaluations and certifications, fifteen patients with a mean age of 71.4 years (SD ±17.7) were enrolled in a pilot study (10 males, 5 females). The FTT NIRS V2 sensor was affixed on the flap to monitor hemodynamics over 72 hours post-operatively. The system successfully monitored all 15 patients, with a mean TOI of 60.1 (SD ±4.4). Two patients experienced venous occlusion with TOI ranging from 41 to 63.5, and one patient with complete flap failure recorded TOI of 52. As a complementary intraoperative experiment, the sensor was placed on the flap tissue after artery and vein isolation to assess hemodynamics during arterial and venous ischemic phases. The protocol included 5 minutes baseline, 5 minutes venous occlusion, 5 minutes recovery, 5 minutes arterial occlusion, and 5 minutes recovery. Patients and clinicians rated their experience with the system on a 1–10 scale. Average patient discomfort was 1.7 (SD ±1.4), and interference with clinical treatment was 1.5 (SD ±0.7). We demonstrated that the FTT NIRS system can monitor for 72 hours post-operatively and differentiate arterial from venous occlusions (P < 0.006). Integrating the FTT NIRS system into standard monitoring could reduce flap failure rates.