The impact of diabetes mellitus on foot perfusion pre- and post-revascularisation measured by near-infrared fluorescence imaging

Introduction: Diabetes Mellitus (DM) contributes to the complexity of lower extremity arterial disease (LEAD), inducing peripheral neuropathy and increasing susceptibility to severe ischemia, foot ulceration, and amputation. Perfusion differences in LEAD patients with and without DM may advocate a more individualised revascularisation strategy than the current WIfI classification for risk prediction. This study aims to utilise near-infrared (NIR) fluorescence imaging with Indocyanine Green (ICG) to assess perfusion parameters before and after revascularisation in DM and non-DM patients and explore their relationship with clinical outcome. Methods ICG NIR fluorescence imaging was performed pre- and post-revascularisation in LEAD patients with and without DM. Three time-related perfusion parameters were analysed to assess differences in perfusion patterns. Clinical improvement (CI) after revascularisation was analysed in chronic limb-threatening ischemia (CLTI) patients with- and without DM. Results Successful revascularisation and ICG NIR fluorescence measurements were conducted in 128 patients (144 limbs), with 42 (48 limbs) DM patients. Two out of three revascularisation parameters post-operatively improved significantly in the DM group, compared to three out of three in the non-DM group. Additionally, in the sub-analyses of the CLTI group, no parameters in the DM CI group showed significant enhancement, compared to significant improvements in all parameters in the non-DM CI group (p = 0.003 - <0.001). A trend towards a lower likelihood of CI was observed in DM CLTI patients, though not statistically significant (86% vs 66%, p = 0.073). Conclusion This study demonstrates the capability of ICG NIR fluorescence to map disparities in the dynamic tissue perfusion between DM and non-DM LEAD patients undergoing revascularisation. In general, ICG NIR fluorescence findings appear to correlate with postoperative outcomes, with CLTI DM patients showing reduced responsiveness to therapy. These findings may pave the way for a more personalised approaches in CLTI revascularisation.