Intramuscular Near-Infrared Spectroscopy for Muscle Flap Monitoring in a Porcine Model
Wubin Bai, Hexia Guo, Wei Ouyang, Yang Weng, Changsheng Wu, Yihan Liu, Hao Zang, Lauren Jacobson, Yameng Xu, Di Lu, Ziying Hu, Shuo Li, Hany Arafa, Quansan Yang, Amanda M. Westman, Matthew R. MacEwan, John A. Rogers, Mitchell A. Pet
Abstract
BACKGROUND: Current near-infrared spectroscopy (NIRS)-based systems for continuous flap monitoring are limited to flaps which carry a cutaneous paddle. As such, this useful and reliable technology has not previously been applicable to muscle-only free flaps where other modalities with substantial limitations continue to be utilized. METHODS: ) directly within the substance of muscle tissue. This probe is flexible, subcentimeter in scale, waterproof, biocompatible, and is fitted with resorbable barbs which facilitate temporary autostabilization followed by easy atraumatic removal. This novel device was compared with a ViOptix T.Ox monitor in a porcine rectus abdominus myocutaneous flap model of arterial and venous occlusions. During these experiments, the T.Ox device was affixed to the skin paddle, while the novel probe was within the muscle component of the same flap. RESULTS: tracings throughout the vascular clamping events, with obvious and parallel changes occurring upon vascular clamping and release. The normalized cross-correlation at zero lag describing correspondence between the novel intramuscular NIRS and T.Ox devices was >0.99. CONCLUSION: This novel intramuscular NIRS probe offers continuous monitoring of oxygen saturation within muscle flaps. This experiment demonstrates the potential suitability of this intramuscular NIRS probe for the task of muscle-only free flap monitoring, where NIRS has not previously been applicable. Testing in the clinical environment is necessary to assess durability and reliability.