Indocyanine Green Angiography Overpredicts Postoperative Necrosis Compared to Multispectral Reflectance Imaging.

Background: Sufficient perfusion is foundational to successful reconstructive surgery. Various technologies have been developed to help determine whether tissue is adequately perfused, or whether it will be prone to necrosis postoperatively. Indocyanine green (ICG) angiography is one such method that uses fluorescence and analyzes tissue perfusion. Multispectral reflectance imaging (MSRI) is an alternative technology that analyzes optical properties of oxygenated and deoxygenated hemoglobin to determine tissue viability. Because tissue in low-perfusion states may still survive because of sufficient oxygenation, the authors hypothesized that compared to MSRI, ICG angiography overpredicts necrosis, potentially resulting in unnecessary resection of viable tissue. This study expands on preliminary work to investigate this hypothesis.

Methods: This was a prospective cohort of patients undergoing prepectoral direct implant reconstruction at a single institution. Each patient was examined intraoperatively with both ICG angiography and MSRI. Decisions to resect tissue were made in conjunction with MSRI and ICG images collected purely for data analysis. Patients were followed postoperatively for at least 2 months for signs of postoperative necrosis.

Results: Fifty-three cases were included. ICG angiography accurately predicted viability in 40 of 40 patients (100%) and incorrectly predicted necrosis in 11 of 13 patients (84.6%). Simultaneously, MSRI predicted necrosis in zero patients and accurately predicted viability in 51 of 53 patients (96.2%). There was no statistically significant difference in demographic data among patients predicted to experience necrosis by means of ICG angiography versus those predicted to have entirely viable tissue.

Conclusion: This study suggests that ICG angiography is prone to overpredicting postoperative necrosis in comparison to MSRI.

Clinical Relevance Statement: This study suggests that multispectral reflectance imaging may benefit practicing plastic surgeons in determining the likelihood of postoperative necrosis.

Clinical Question/level Of Evidence: Diagnostic, II.