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Contemporary quality control methods are often insufficient in predicting clinical outcomes after revascularization in lower extremity arterial disease (LEAD) patients. This study evaluates the potential of near-infrared fluorescence imaging with indocyanine green to predict the clinical outcome following revascularization. Near-infrared fluorescence imaging was performed before and within 5 days following the revascularization procedure. Clinical improvement was defined as substantial improvement of pain free walking distance, reduction of rest- and/or nocturnal pain, or tendency toward wound healing. Time-intensity curves and 8 perfusion parameters were extracted from the dorsum of the treated foot. The quantified postinterventional perfusion improvement was compared within the clinical outcome groups. Successful near-infrared fluorescence imaging was performed in 72 patients (76 limbs, 52.6% claudication, 47.4% chronic limb-threatening ischemia) including 40 endovascular- and 36 surgical/hybrid revascularizations. Clinical improvement was observed in 61 patients. All perfusion parameters showed a significant postinterventional difference in the clinical improvement group ( P -values <.001), while no significant differences were seen in the group without clinical improvement ( P -values .168-.929). Four parameters demonstrated significant differences in percentage improvement comparing the outcome groups ( P -values within .002-.006). Near-infrared fluorescence imaging has promising additional value besides clinical parameters for predicting the clinical outcome of revascularized LEAD patients., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Patients with lower extremity arterial disease (LEAD) frequently require revascularization procedures. Currently used diagnostic methods are insufficient in predicting successful outcomes and focus on macrovascular rather than microvascular state. Several promising modalities to increase diagnostic accuracy are emerging, including maximal systolic acceleration (ACC max ), measured by duplex ultrasound (DUS). For the assessment of tissue perfusion, near-infrared fluorescence (NIR) imaging using indocyanine green (ICG) demonstrates promising results. This study aims to identify the usefulness of combining these two methods for macrovascular and microvascular perfusion assessment to predict successful clinical outcomes., Methods: A retrospective study was performed collecting preinterventional and postinterventional DUS and ICG NIR fluorescence imaging measurements from LEAD patients undergoing revascularization. The correlation between the preinterventional and postinterventional perfusion parameters, described as the delta (Δ) ACC max and ΔICG NIR fluorescence parameters, were analyzed. Improvements in perfusion parameters were compared to clinical outcomes, defined as improvement in pain-free walking distance, freedom from rest pain, or tendency toward wound and ulcer healing., Results: A total of 38 patients (42 limbs) were included. ACC max and ICG NIR fluorescence perfusion parameters improved significantly after revascularization (p<0.001). Patients with a poor clinical outcome had a significantly lower improvement of both parameters after revascularization (p<0.001-0.016). Lack of correlation was found between the delta of ACC max and ICG NIR fluorescence imaging. Multiple non-congruent improvements of macrovascular parameters (ACC max ) and perfusion (ICG NIR fluorescence) were seen within patients. However, for all patients with a successful clinical outcome, at least one parameter improved., Conclusion: Combining ACC max and ICG NIR fluorescence imaging revealed improvement in at least one parameter within all patients with a successful clinical outcome. This study highlights the potential of assessing both the macrovascular state and tissue perfusion following lower extremity revascularization, as both appear to reflect different aspects of vascularization., Clinical Impact: Numerous techniques have been developed to assess tissue perfusion to predict clinical outcomes following revascularization in patients with peripheral artery disease. However, none are widely implemented in clinical practice. This study emphasized the importance of employing multiple modalities from different perspectives for more accurate prediction. By focusing on both the macrovascular state and tissue perfusion, clinicians can better guide themselves in their treatment strategies., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: Diabetes Mellitus (DM) is a common chronic disease, affecting 435 million people globally. Impaired vasculature in DM patients leads to complications like lower extremity arterial disease (LEAD) and foot ulcers, often resulting in amputations. DM causes additional peripheral neuropathy leading to multifactorial wound problems. Current diagnostics often deem unreliable, but Near-Infrared Fluorescence with Indocyanine Green (ICG NIR) can be used to assess the foot perfusion. Therefore, this study explores DM's impact on foot perfusion using ICG NIR., Methods: Baseline ICG NIR fluorescence imaging was performed in LEAD patients with and without DM. Ten perfusion parameters were extracted and analyzed to assess differences in perfusion patterns., Results: Among 109 patients (122 limbs) of the included patients, 32.8 % had DM. Six of ten perfusion parameters, mainly inflow-related, differed significantly between DM and non-DM patients (p-values 0.007-0.039). Fontaine stage 4 DM patients had the highest in- and outflow values, with seven parameters significantly higher (p-values 0.004-0.035)., Conclusion: DM is associated with increased in- and outflow parameters. Patients with- and without DM should not be compared directly due to different vascular pathophysiology and multifactorial wound problems in DM patients. Quantified ICG NIR fluorescence imaging offers additional insight into the effect of DM on foot perfusion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Indocyanine green near-infrared fluorescence bowel perfusion assessment has shown its potential benefit in preventing anastomotic leakage. However, the surgeon's subjective visual interpretation of the fluorescence signal limits the validity and reproducibility of the technique. Therefore, this study aimed to identify objective quantified bowel perfusion patterns in patients undergoing colorectal surgery using a standardized imaging protocol., Method: A standardized fluorescence video was recorded. Postoperatively, the fluorescence videos were quantified by drawing contiguous region of interests (ROIs) on the bowel. For each ROI, a time-intensity curve was plotted from which perfusion parameters (n = 10) were derived and analyzed. Furthermore, the inter-observer agreement of the surgeon's subjective interpretation of the fluorescence signal was assessed., Results: Twenty patients who underwent colorectal surgery were included in the study. Based on the quantified time-intensity curves, three different perfusion patterns were identified. Similar for both the ileum and colon, perfusion pattern 1 had a steep inflow that reached its peak fluorescence intensity rapidly, followed by a steep outflow. Perfusion pattern 2 had a relatively flat outflow slope immediately followed by its plateau phase. Perfusion pattern 3 only reached its peak fluorescence intensity after 3 min with a slow inflow gradient preceding it. The inter-observer agreement was poor-moderate (Intraclass Correlation Coefficient (ICC): 0.378, 95% CI 0.210-0.579)., Conclusion: This study showed that quantification of bowel perfusion is a feasible method to differentiate between different perfusion patterns. In addition, the poor-moderate inter-observer agreement of the subjective interpretation of the fluorescence signal between surgeons emphasizes the need for objective quantification., (© 2023. The Author(s).)

Background: The angiosome concept is defined as the anatomical territory of a source artery within all tissue layers. When applying this theory in vascular surgery, direct revascularization (DR) is preferred to achieve increased blood flow toward the targeted angiosome of the foot in patients with lower extremity arterial disease (LEAD). This study evaluates the applicability of the angiosome concept using quantified near-infrared (NIR) fluorescence imaging with indocyanine green (ICG)., Methods: This study included patients undergoing an endovascular- or surgical revascularization of the leg between January 2019 and December 2021. Preinterventional and postinterventional ICG NIR fluorescence imaging was performed. Three angiosomes on the dorsum of the foot were determined: the posterior tibial artery (hallux), the anterior tibial artery (dorsum of the foot) and the combined angiosome (second to fifth digit). The angiosomes were classified from the electronic patient records and the degree of collateralization was classified based on preprocedural computed tomography angiography and/or X-ray angiography. Fluorescence intensity was quantified in all angiosomes. A subgroup analysis based on endovascular or surgical revascularized angiosomes, and within critical limb threatening ischemia (CLTI) patients was performed., Results: ICG NIR fluorescence measurements were obtained in 52 patients (54 limbs) including a total of 157 angiosomes (121 DR and 36 indirect revascularizations [IR]). A significant improvement of all perfusion parameters in both the directly and indirectly revascularized angiosomes was found (P-values between <0.001-0.007). Within the indirectly revascularized angiosomes, 90.6% of the scored collaterals were classified as significant. When comparing the percentual change in perfusion parameters between the directly and indirectly revascularized angiosomes, no significant difference was seen in all perfusion parameters (P-values between 0.253 and 0.881). Similar results were shown in the CLTI patients subgroup analysis, displaying a significant improvement of perfusion parameters in both the direct and indirect angiosome groups (P-values between <0.001 and 0.007), and no significant difference when comparing the percentual parameter improvement between both angiosome groups (P-values between 0.134 and 0.359). Furthermore, no significant differences were observed when comparing percentual changes of perfusion parameters in directly and indirectly revascularized angiosomes for both endovascular and surgical interventions (P-values between 0.053 and 0.899)., Conclusions: This study proves that both DR and IR of an angiosome leads to an improvement of perfusion. This suggests that interventional strategies should not only focus on creating in-line flow to the supplying angiosome. One can argue that the angiosome concept is not applicable in patients with LEAD., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Anastomotic leakage is a severe complication after oesophageal resection with gastric conduit reconstruction. Poor perfusion of the gastric conduit plays an important role in the development of anastomotic leakage. Quantitative near-infrared (NIR) fluorescence angiography with indocyanine green (ICG-FA) is an objective technique that can be used for perfusion assessment. This study aims to assess perfusion patterns of the gastric conduit with quantitative ICG-FA., Methods: In this exploratory study, 20 patients undergoing oesophagectomy with gastric conduit reconstruction were included. A standardized NIR ICG-FA video of the gastric conduit was recorded. Postoperatively, the videos were quantified. Primary outcomes were the time-intensity curves and nine perfusion parameters from contiguous regions of interest on the gastric conduit. A secondary outcome was the inter-observer agreement of subjective interpretation of the ICG-FA videos between six surgeons. The inter-observer agreement was tested with an intraclass correlation coefficient (ICC)., Results: In a total of 427 curves, three distinct perfusion patterns were recognized: pattern 1 (steep inflow, steep outflow); pattern 2 (steep inflow, minor outflow); and pattern 3 (slow inflow, no outflow). All perfusion parameters were significantly different between the perfusion patterns. The inter-observer agreement was poor - moderate (ICC:0.345,95%CI:0.164-0.584)., Discussion: This was the first study to describe perfusion patterns of the complete gastric conduit after oesophagectomy. Three distinct perfusion patterns were observed. The poor inter-observer agreement of the subjective assessment underlines the need for quantification of ICG-FA of the gastric conduit. Further studies should evaluate the predictive value of perfusion patterns and parameters on anastomotic leakage., Competing Interests: Declaration of competing interest All authors declare no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: One of the complications of free flap breast reconstruction is the occurrence of skin and fat necrosis. Intra-operative use of near-infrared (NIR) fluorescence imaging 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 imaging., 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®. Four regions of interest (ROI) were selected based on location and interpretation of the NIR fluorescence signal: (1) The perforator, (2) normal perfusion, (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 questionable 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 fluorescence imaging in free flap breast reconstruction. Future studies should correlate quantitative parameters with clinical perfusion assessment and outcome., Competing Interests: Declaration of Competing Interest All authors state to have no conflict of interest., (Copyright © 2022 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)