Ultrasound Hemodynamics of SCIA-SIEA System: A Foundation for Groin Flap Planning

The superficial circumflex iliac artery perforator (SCIP) flap has become an essential option in reconstructive microsurgery. However, the arterial anatomy of the groin region demonstrates substantial variation, with reports of superficial circumflex iliac artery (SCIA) hypoplasia necessitating reliance on the superficial inferior epigastric artery (SIEA) as an alternative vascular source. This study aimed to characterize and compare hemodynamic differences among these arteries to determine whether physiological, in addition to morphological, variability exists.

Ultrasound was used to assess morphological and physiological parameters of the SCIA superficial and deep branches, as well as the SIEA, in 54 inguinal regions from 27 healthy volunteers. Measurements were obtained at defined anatomical landmarks, recording peak systolic velocity (PSV) and resistance index (RI). Cases were categorized based on PSV distribution patterns to describe relative flow predominance and potential variations in vascular contribution between arteries.

Significant differences were noted in PSV among the three arteries (p < 0.00001), primarily between the SCIA branches and the SIEA (superficial SCIA vs. SIEA, p < 0.00001; deep SCIA vs. SIEA, p < 0.00001). Three main flow distribution patterns were described: Dominance of a single artery (18.5%), a single underdeveloped artery with reduced PSV (64.8%), and balanced flow among all three arteries (16.7%). No significant side-to-side differences were observed (all p > 0.75).

Distinct interindividual hemodynamic patterns of arterial perfusion in the groin region can be identified using ultrasound, and baseline reference values are established to support further validation of preoperative mapping for SCIP and SIEA flaps.