Background. Paravertebral regional anaesthesia is used to treat pain after several surgical
procedures. This study aimed to improve on our first published ultrasound-guided approach
to the paravertebral space (PVS) and to investigate a possible discrepancy between the
needle, catheter, and contrast dye position.
Methods. In 10 cadavers, we conducted 26 ultrasound-guided paravertebral approaches
combined with loss of resistance (LOR) and after an interim analysis performed 36 novel,
pure ultrasound-guided (PUSG) paravertebral approaches. Needle-tip position was
controlled by a first computed tomography (CT) scan. After placement of the catheters,
the tips were assessed by a second CT and the spread of injected contrast dye was
assessed by further CT scans. The part of the PVS near the intervertebral foramen was
defined as the primary target to reach.
Results. The first CT scans assessing 62 needle tips revealed that: 13 (50%) of LOR and 34
(94%) of PUSG approaches were at the target; and two (8%) LOR and no PUSG approaches
were outside the PVS. With the second CT scans 60 catheter-tip positions were analysed:
three (12%) of LOR and five (14%) of PUSG approaches were at the target, three (12%) of
LOR and two (6%) of PUSG approaches were outside the PVS. No catheters were detected
in the epidural space. In two cases, insertion of the catheter was not possible. In cases
with major epidural contrast, the widest contrast dye spread was 7.7 (3.5) [mean (SD)]
vertebral segments.
Conclusions. Our new PUSG technique has a high success rate for paravertebral needle
placement. Although needles were correctly positioned, catheters were usually found
distant from the needle-tip position.
Keywords: anatomy, regional; intercostal nerv