Bilateral postoperative ultrasound-guided erector spinae plane block in open abdominal hysterectomy: a case series and cadaveric investigation.

We anticipated that bilateral Erector spinae plane (ESP) block, which was applied in 10 patients starting from lower thoracic levels (T9) might provide effective postoperative analgesia in open abdominal hysterectomies. In addition, we aimed to obtain anatomic observation of the local anaesthetic (LA) spread in the ESP block by injecting methylene blue on 4 cadavers. All the patients had excellent pain relief. There was an extensive spread to the erector spinae muscle (ESM) involving several segmental levels on cadavers. We observed the spread of dye on the ventral and dorsal rami in the paravertebral space and as an additional finding, the dye had extended to the canal vertebralis. There was a spread of dye on the dura mater. ESP block can be used with new indications and it is an effective technique for major abdominal surgery when is applied to the lower vertebral levels. Randomized controlled trials are required to explore the clinical implications of our findings.