UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Free tissue transfer monitoring using a novel near infrared spectroscopy system Mah, Aaron


Free tissue transfer (FTT) is a surgical procedure that involves taking tissue from one area of the body and transplanting it to a surgical wound. Vascular complications to the tissue can result in FTT failure, and the transplanted tissue can die. Early detection of vascular compromise is critical for successful salvage of the transplanted tissue. Near-infrared spectroscopy (NIRS) has the potential to provide continuous and non-invasive monitoring of FTT hemodynamics and oxygenation. However, there are currently no commercially available NIRS systems with a small enough sensor probe to be used in the head and neck region. A novel NIRS system with a miniaturized implantable sensor was developed for FTT monitoring in head and neck surgery. The objectives of this study were to obtain post-operative NIRS measurements on a cohort of patients undergoing FTT surgery for a head and neck reconstruction and to evaluate the patient’s and clinician’s experience with the novel NIRS monitoring method. Four adult participants undergoing a FTT operation for a head and neck reconstruction were recruited for participation in the study. The NIRS sensor was fixed over the FTT for 72 hours post-operatively to provide tissue oxygenation parameters, including oxygenated hemoglobin (O₂Hb), deoxygenated hemoglobin (HHb), and tissue oxygenation index (TOI). After 72 hours, the patient and clinicians completed a questionnaire to evaluate their experience with the NIRS system. All patients undergoing FTT surgery had a successful operation with no complications to the FTT. The NIRS data showed visible pulsatile O₂Hb signals, indicating sufficient microvascular function and perfusion to the FTT. Furthermore, changes in TOI% of the FTT were within a normal healthy tissue range of 63-93% in all four patients during the monitoring period. The results of the questionnaires indicated that the NIRS sensor did not cause additional discomfort or inconvenience to the patients or clinicians. We demonstrated that the FTT-NIRS system can monitor FTT hemodynamics and oxygenation continuously and non-invasively for 72 hours post-operatively following a head and neck reconstruction. Incorporating a novel NIRS system into routine post-operative care following FTT surgery shows great potential to improve post-operative monitoring and decrease FTT failure rates.

Item Media

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International