Perfusion parameters in near-infrared fluorescence imaging with indocyanine green: a systematic review of the literature

(1) Background: Near-infrared fluorescence imaging is a technique capable of assessing tissue perfusion and has been adopted in various fields including plastic surgery, vascular surgery, coronary arterial disease, and gastrointestinal surgery. While the usefulness of this technique has been broadly explored, there is a large variety in the calculation of perfusion parameters. In this systematic review, we aim to provide a detailed overview of current perfusion parameters, and determine the perfusion parameters with the most potential for application in near-infrared fluorescence imaging. (2) Methods: A comprehensive search of the literature was performed in Pubmed, Embase, Medline, and Cochrane Review. We included all clinical studies referencing near-infrared perfusion parameters. (3) Results: A total of 1511 articles were found, of which, 113 were suitable for review, with a final selection of 59 articles. Near-infrared fluorescence imaging parameters are heterogeneous in their correlation to perfusion. Time-related parameters appear superior to absolute intensity parameters in a clinical setting. (4) Conclusions: This literature review demonstrates the variety of parameters selected for the quantification of perfusion in near-infrared fluorescence imaging.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

Assessment of deep inferior epigastric perforator flap perfusion with near-infrared fluorescence: A pilot study and description of a standardized working protocol

Michi, Verduijn, as it either provided additional information about perfusion or confirmed the clinical assess-ment. Our pilot study showed a significant decrease of FN in patients undergoing an ABR with a DIEP when near-infrared fluorescence imaging was used to assess flap perfusion. This study provides a standardized working protocol for near-infrared fluorescence imaging. In the future, large multicenter studies should focus on the quantification of near-infrared fluorescence imaging. (c) 2021 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Else-vier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/

Assessment of deep inferior epigastric perforator flap perfusion with near-infrared fluorescence: A pilot study and description of a standardized working protocol

Michi, Verduijn, as it either provided additional information about perfusion or confirmed the clinical assess-ment. Our pilot study showed a significant decrease of FN in patients undergoing an ABR with a DIEP when near-infrared fluorescence imaging was used to assess flap perfusion. This study provides a standardized working protocol for near-infrared fluorescence imaging. In the future, large multicenter studies should focus on the quantification of near-infrared fluorescence imaging. (c) 2021 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Else-vier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )Surgical oncolog

Near-infrared fluorescence angiography with indocyanine green for perfusion assessment of DIEP and msTRAM flaps: A Dutch multicenter randomized controlled trial

Background: A common complication after a DIEP flap reconstruction is the occurrence of fat necrosis due to inadequate flap perfusion zones. Intraoperative identification of ischemic zones in the DIEP flap could be optimized using indocyanine green near-infrared fluorescence angiography (ICG-NIR-FA). This randomized controlled trial aims to determine whether intraoperative ICG-NIR-FA for the assessment of DIEP flap perfusion decreases the occurrence of fat necrosis. Design/methods: This article describes the protocol of a Dutch multicenter randomized controlled clinical trial: the FAFI-trial. Females who are electively scheduled for autologous breast reconstruction using DIEP or muscle-sparing transverse rectus abdominis muscle (msTRAM) flaps are included. A total of 280 patients will be included in a 1:1 ratio between both study arms. In the intervention arm, the intraoperative assessment of flap perfusion will be based on both regular clinical parameters and ICG-NIR-FA. The control arm consists of flap perfusion evaluation only through the regular clinical parameters, while ICG-NIR-FA images are obtained during surgery for which the surgeon is blinded. The main study endpoint is the difference in percentage of clinically relevant fat necrosis between both study arms, evaluated two weeks and three months after reconstruction. Conclusion: The FAFI-trial, a Dutch multicenter randomized controlled clinical trial, aims to investigate the clinical added value of intraoperative use of standardized ICG-NIR-FA for assessment of DIEP/msTRAM flap perfusion in the reduction of fat necrosis. Clinical trial registration number: NCT05507710; NL 68623.058.18

Quantification of near-infrared fluorescence imaging with indocyanine green in free flap breast reconstruction

Background: One of the complications of free flap breast reconstruction is the oc-currence of skin and fat necrosis. Intra-operative use of near-infrared (NIR) fluorescence imag-ing with Indocyanine Green (ICG) has the potential to predict these complications. In this study, the quantification of the fluorescence intensity measured in free flap breast reconstruction was performed to gain insight into the perfusion patterns observed with ICG NIR fluorescence imag-ing.Methods: ICG NIR fluorescence imaging was performed in patients undergoing free flap breast reconstruction following mastectomy. After completion of the arterial and venous anastomosis, 7.5 mg ICG was administered intravenously. The fluorescence intensity over time was recorded using the Quest Spectrum Platform (R). Four regions of interest (ROI) were selected based on location and interpretation of the NIR fluorescence signal: (1) The perforator, (2) normal per -fusion, (3) questionable perfusion, and (4) low perfusion. Time-intensity curves were analyzed, and two parameters were extracted: Tmax and Tmax slopes.Results: Successful ICG NIR fluorescence imaging was performed in 13 patients undergoing 17 free flap procedures. Region selection included 16 perforators, 17 normal perfusions, 8 ques-tionable perfusions, and 5 low perfusion ROIs. Time-intensity curves of the perforator ROIs were comparable to the ROIs of normal perfusion and demonstrated a fast inflow. No outflow was observed for the ROIs with questionable and low perfusion.Conclusion: This study provides insight into the perfusion patterns observed with ICG NIR flu-orescence imaging in free flap breast reconstruction. Future studies should correlate quantita-tive parameters with clinical perfusion assessment and outcome.(c) 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Pub-lished by Elsevier Ltd. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/