Functional detection of external iliac artery endofibrosis in a cyclist: integrating performance metrics and vascular imaging, a case study

Abstract Purpose Identifying external iliac artery endofibrosis (EIAE) remains challenging and may lead to a reduction in cycling performance. This case study describes diagnosis process and changes in performance prior to and during recovery in a cyclist with EIAE. Power-Duration data, laboratory-based Lactate Thresholds (LT) assessments, and vascular evaluation data were integrated in a comprehensive attempt to characterise performance changes associated with EIAE. Methods The Power-Duration profile was obtained from the 2022–2024 seasons. Graded Exercise Tests were performed 90 days before (GXT1) and 90 and 172 days after treatment (GXT2, GXT3), assessing Power Output (PO) and blood lactate, LT (LTP1, Dmaxmod) were estimated, and left/right leg PO (LPO, RPO). In addition, vascular evaluation under an Exercise-Induced Claudication Test (EICT) was performed. Results Power-Duration profile showed a decline in performance across 5–60-min durations in 2023 and 2024 compared with 2022, with reductions ranging from − 1.2% to − 15.6%. Estimated Left–Right Balance (L/R-B) at LT ranged from 47 to 49% at GXT1, decreased to 46–47% at GXT2, and increased to 52–53% at GXT3, indicating dynamic inter-limb changes throughout time tests. Vascular assessment revealed kinking of the left iliac axis, with suspicion in the right axis, which was confirmed at the end of the study. Conclusion Novel power-based assessments across multiple durations, in this case study, helped to evaluate performance decrements associated with EIAE. Lower-limb PO derived from the GXT appeared sensitive detecting inflection points indicative of performance loss potentially related to underlying vascular pathology. Echo-Doppler provided significant evidence confirmed by intravascular ultrasound and intraoperative findings.