Ultrasound imaging findings of femoral veins in patients with renal failure and its impact on vascular access.

Background: Patients requiring dialysis due to acute or chronic renal failure frequently require temporary vascular access. Femoral vein catheterization is the easiest method for obtaining temporary vascular access in haemodialysis patients. The aim of this study was to utilize ultrasound imaging to describe femoral vein structures and to examine anatomical variations in uraemic patients.
Methods: We evaluated 114 (70 males, 44 females) renal failure patients. Femoral arteries were localized manually inferior to the femoral ligament, and ultrasonographic examination was performed from this location. Images of the vessels and demographic data of patients were recorded and analysed. Femoral veins were classified according to their diameter, patency and palpation status of the neighbouring femoral artery.
Results: Three patients had a history of prior femoral catheterization. In one of these, who had a history of bilateral catheterization, we detected bilateral femoral vein thrombosis. Overall, non-palpable femoral arteries or unsuitable femoral veins were found unilaterally in 16 patients (14.0%) and bilaterally in six patients (5.2%). The depth of femoral arteries (r = 0.54, P<0.001) and femoral veins (r = 0.59, P<0.001) was correlated with body mass index (BMI). Femoral arteries and femoral veins were located significantly deeper in overweight (BMI >25) patients compared with normal weight patients (20.7+/-6.5 vs 14.6+/-5.1 mm, P<0.001 and 26.1+/-6.7 vs 18.9+/-5.5 mm, P<0.001).
Conclusions: Bilateral anatomical variations of femoral veins were relatively rare. However, ultrasound surveys should be performed in obese patients or when the femoral artery is not palpable.