Improving intraoperative perfusion reliability in anterolateral thigh free flap reconstruction for diabetic foot ulcers

Table 2 Proposed minimum reporting set for standardized quantitative indocyanine green fluorescence angiography in diabetic foot ulcer anterolateral thigh free-flap reconstruction

Reporting domain	Minimum items to report (recommended)	Why it matters	Outcome anchoring
Patient and limb ischemia phenotype	Diabetes duration/type; PAD history; prior revascularization (type, timing); ulcer location/angiosome; infection status	Baseline heterogeneity strongly shapes perfusion signals and failure risk	Stratify analyses by ischemia phenotype and revascularization status
Distal perfusion capacity (pre-op baseline)	Toe pressure/TBI, SPP, TcPO2 (site, temperature settings, timing); Doppler waveform	Interprets ICG-FA within a “distal capacity ceiling”; mitigates ABI distortion in medial calcification	Use clinically meaningful thresholds and report proportion meeting targets
ICG agent and administration	ICG dose (mg/kg), concentration, injection rate/flush volume, injection site, repeat-injection interval	Dose/rate substantially change curve shape and saturation; critical for reproducibility	Report adverse reactions; document repeated runs and reasons
Imaging system and acquisition settings	Device model; excitation/emission band; working distance; gain/exposure; frame rate; ambient light control; start time relative to injection	Controls systematic measurement drift across platforms and cases	Provide calibration/QA steps if available
ROI definition rules	ROI anatomical landmarks; size/shape; number of ROIs (central vs peripheral, suspected hypoperfusion zones); method for background subtraction	ROI selection is a dominant source of between-study variability	Predefine ROI plan; avoid “post-hoc ROI fishing”
Primary kinetic parameters (FTC-based)	Wash-in slope; Tmax; AUC; Fmax; time-to-10%/90% rise (if used); normalization method	Kinetic metrics are less sensitive than intensity-only metrics and reflect inflow/exchange dynamics	Specify how curves are extracted (software, smoothing, interpolation)
Decision rules during surgery	Criteria for margin trimming, re-anastomosis, supercharging, warming/vasodilator use; whether decisions were blinded to kinetics	Enables evaluation of clinical utility and prevents circular reasoning	Link each decision to subsequent necrosis/complication endpoints
Systemic physiology at imaging	MAP/vasopressors; temperature; hemoglobin; SpO2/PaO2; PaCO2/ventilation strategy; fluid balance	ICG-FA reflects a systemic-regional-microcirculatory continuum; systemic variables confound kinetics	Report concurrent systemic targets and deviations
Comparator modalities (if available)	NIRS StO2 trends; TcPO2/TcPCO2; LDF/LSCI; thermography	Multimodal validation improves credibility and mechanistic inference	Predefine primary/secondary validation endpoints
Clinical endpoints	Partial/total flap necrosis (definition, timing); take-back/re-exploration; wound healing time; limb salvage; LOS	Avoids endpoint heterogeneity, enabling meta-analysis/registry utility	Mandatory follow-up window and adjudication process

ABI: Ankle-brachial index; AUC: Area under the curve; FTC: Fluorescence-time curve; ICG-FA: Indocyanine green fluorescence angiography; LDF/LSCI: Laser Doppler flowmetry/Laser speckle contrast imaging; LOS: Length of stay; MAP: Mean arterial pressure; NIRS: Near-infrared spectroscopy; PaCO₂: Partial pressure of arterial carbon dioxide; PAD: Peripheral artery disease; PaO₂: Partial pressure of arterial oxygen; QA: Quality assurance; ROI: Region of interest; SpO₂: Peripheral capillary oxygen saturation; SPP: Skin perfusion pressure; StO₂: Tissue oxygen saturation; TBI: Toe-brachial index; TcPO₂: Transcutaneous oxygen tension; Tmax: Time to maximum intensity.