# Ultrasound-guided erector spinae plane block versus rhomboid intercostal sub-serratus plane block for postoperative analgesia in open radical nephrectomy: a randomized clinical study

## TL;DR

This study compares two regional anesthesia techniques for pain relief after kidney surgery, finding one to be slightly more effective.

## Contribution

A direct comparison of ultrasound-guided ESPB and RISS block for postoperative analgesia in open radical nephrectomy.

## Key findings

- ESPB group had significantly lower morphine consumption in the first 24 postoperative hours.
- ESPB group showed significantly lower pain scores at rest and with movement at multiple time points.
- ESPB group had a longer time to first postoperative analgesia request.

## Abstract

Open radical nephrectomy often results in significant acute postoperative pain. Regional anesthesia offers an alternative analgesic approach in these situations. This study aims to assess and compare the effectiveness of ultrasound-guided rhomboid intercostal sub-serratus (RISS) block with Erector Spinae Plane Block (ESPB) in patients undergoing open radical nephrectomy.

This randomized clinical trial included 42 patients scheduled for open radical nephrectomy (RN). Patients were randomly assigned to one of two groups: the ESPB Group (n = 21), which received an ESPB with 30 ml of bupivacaine 0.25%, or the RISS Group (n = 21), which received a RISS block with 30 ml bupivacaine 0.25%. Total morphine consumption was set as the primary outcome while pain scores, perioperative hemodynamics and time to postoperative analgesia were considered as secondary outcomes.

Total morphine consumption within the first 24 postoperative hours was significantly lower for the ESPB group (16.4 ± 2.5 mg) compared to the RISS group (18.2 ± 1.8 mg), p = 0.011. VAS pain scores at rest were significantly lower in the ESPB group at 12 and 18 h (p = 0.002, p = 0.018) respectively. VAS scores with movement were significantly lower for the ESPB group at 8 h,12 h, and 18 h (p = 0.011, p = 0.001, and p = 0.018 respectively). The first time to receive postoperative analgesia was significantly longer in the ESPB group (7.3 ± 2.1 h) than in the RISS group (6.0 ± 2.1 h), p = 0.048. Both groups were comparable in the number of PCA boluses, the number of patients requiring intraoperative fentanyl increments, or recovery time.

Ultrasound-guided ESPB provides slightly superior postoperative analgesia compared with RISS block in patients undergoing open radical nephrectomy via subcostal anterior incision for renal malignancies.

The trial was registered at Clinical Trials.gov. https://clinicaltrials.gov/study/NCT05822011, trial ID (NCT05822011, 14 March 2023).

The online version contains supplementary material available at 10.1186/s12871-025-03377-4.