Use of Near-infrared Spectroscopy and Implantable Doppler for Postoperative Monitoring of Free Tissue Transfer for Breast Reconstruction: A Systematic Review and Meta-analysis

Free tissue transfer (FTT) for breast reconstruction following mastectomy has become a standard procedure on account of its superior aesthetics and durability compared with implant reconstruction. Vascular microanastomosis is a critical step for tissue survival. Anastomosis failure causes a lack of oxygen and nutrients to be perfused within the FTT: thrombus or bleeding of either the recipient artery or donor vein may lead to ischemia and congestion, respectively, which may contribute to tissue necrosis. Studies have described that venous thrombosis is the most common microsurgical complication followed by arterial thrombosis and bleeding.4 Most microsurgical complications have been reported to happen within the first 24–48 hours following surgery with higher rates within the first 4 hours.5 Close monitoring is therefore necessary to detect signs of vascular complications to salvage the FTT and decrease the failure rate.1–3 Although there is no standardization, conventional clinical assessments (CCA) usually consists of regular visual and kinetic evaluations of the FTT. As the final health status depends on the expertise of the clinical team, additional tools are often used. Hand-held acoustic Doppler sonography can also be used for assessment of the blood flow across pedicles. However, these assessments are discrete, prone to human error, and, cannot provide prompt, real time and systematic detection of possible microanastomotic complications. Due to the shortcomings of CCA, devices based on the biophysical and biochemical tissue properties have been developed for continuous monitoring of the FTT. Specifically, near-infrared spectroscopy (NIRS) and implantable ultrasound Doppler (ID) devices have been commonly used for continuous and objective assessment of the tissue health.6–8 In the context of growing interest in the use of NIRS and ID to aid early detection of FTT complication and to prevent adverse patient outcomes, it is pertinent that current evidence in regard to these technologies is reviewed. The purpose of this systematic review is to compare the clinical outcomes of NIRS and/or ID and CCA for FTT monitoring.