Feasibility of ultrasound-guided lumbar epidural access using paramedian transverse scanning with the needle in-plane: a comparison with paramedian sagittal scanning

Background and objectives The present study was designed to compare the feasibility of ultrasound (US)-guided lumbar epidural access using paramedian sagittal scanning (PMSS) and paramedian transverse scanning (PMTS) approaches. Methods Fifty patients undergoing surgery of the lower extremities were randomly allocated into 2 groups. The patients in PMSS group received PMSS-guided in-plane epidural access, whereas patients in PMTS group received PMTS-guided in-plane epidural access. The US visibility of neuraxial structures and of Tuohy needle during US scout scan, procedure duration, the number of attempts to access epidural space, Tuohy needle puncture depth in the epidural space, and extent of sensory block after spinal block between two groups were compared. Results The US visibility of Tuohy needle and neuraxial structures was comparable between two groups. There was an overall decrease in procedure duration in the PMTS group relative to the PMSS group (360 ± 42 vs. 490 ± 38 s). The number of attempts needed to access the epidural space in PMSS group was significantly higher than in PMTS group. Distances between the epidural space and the puncture site in PMSS group and PMTS group showed a significant difference (7.13 ± 0.67 vs. 5.24 ± 0.21 cm). No significant differences in the extent of sensory block after spinal block were observed. Conclusions We found that PMTS approach was superior as a means of achieving epidural access relative to the PMSS approach, since PMTS approach can be conducted more quickly given shorter path of the needle and less times needed for epidural access during this procedure. Clinical trial registration Chinese Clinical Trial Registry, clinical trial number ChiCTR1800015815, date of registration April 24, 2018.