Ultrasound-guided oblique short-axis adductor canal block: Can the oblique approach facilitate perineural catheter...

The transverse short-axis in-plane is the standard approach for ultrasound-guided perineural catheter insertion and threading during adductor canal block (BCA). We hypothesized that the oblique short-axis in-plane approach could simplify and speed up catheter insertion and threading by eliminating some technical difficulties.

We included 50 patients aged ≥18 years, ASA I and II, who were scheduled for unilateral knee arthroscopy under spinal anesthesia. We planned to use BCA with a perineural catheter for postoperative analgesia. After administering spinal anesthesia, the patients were randomly assigned to the oblique (oblique short-axis in-plane approach) or transverse (stamdard short-axis in-plane approach) groups. The primary endpoint was catheter insertion time. The secondary endpoints were catheter threading difficulty, and incidence of vascular puncture and catheter migration.

The catheter insertion time was significantly shorter in the oblique group vs the transverse group (113.8 ± 49.2 s vs 185.8 ± 46.7 s, respectively, P < 0.001). Catheter threading was significantly easier in the oblique group, as shown by the lower threading difficulty score compared to the transverse group. Both groups were comparable in terms of the incidence of vascular puncture and catheter migration.

In patients who underwent knee arthroscopy under spinal anesthesia, the oblique short-axis in-plane approach for catheter insertion during BCA was faster and less technically challenging than the standard transverse short-axis in-plane approach.