Increased Needle Visibility in Ultrasound-Guided Percutaneous Liver Biopsy by an Echogenic Sheath: A Proof of Concept Study in a Human Cadaver

For the safety and success of an ultrasound-guided percutaneous liver biopsy, needle visibility and needle tip identification are critical. The aim of this pilot study was to evaluate the influence of an innovative echogenic sheath placed over a standard biopsy needle on needle visibility in ultrasound imaging.

Ultrasound videos of three sheaths with different coating characteristics (echogenicity) and one conventional liver biopsy needle were recorded at two angles (30° and 60°) and two depths (5 and 10 cm) in a human cadaver. The videos were blinded for needle type and presented to five independent radiologists who used Likert-scale scoring to rank each video for six characteristics on needle visibility. In addition, a phantom model was used to acquire standardized images for quantitative evaluation of the ultrasound visibility. Comparative statistical analysis consisted of a one-way ANOVA.

The three prototype sheaths were ranked higher than the control needle at 60° with 5 cm depth, with an equal performance for the other conditions. The radiologists expressed more confidence in taking a biopsy with the echogenic sheaths than with the control needle, with 1 Likert score difference at 30°. Contrast analysis in the phantom model showed a statistically significant effect of a sheath (p = 0.004) on echogenic intensity.

This pilot study suggests that the use of an echogenic sheath may increase needle visibility, particularly for trajectories requiring steeper insertion angles. To investigate the superiority of the echogenic sheath over conventional needles, a clinical study is necessary.