High variability of in-depth injective spread in the erector spinae plane block: a cadaveric anatomical insight

Continuous Erector Spinae Plane Block for Pain Management Following Thoracotomy for Aortic Coarctectomy

Pain following thoracotomy is one of the most severe forms of postoperative pain. Post-thoracotomy pain may increase the risk of post-surgical pulmonary complications, postoperative mortality, prolong hospitalization, and increase utilization of healthcare resources. To mitigate these effects, anesthesia providers commonly employ continuous epidural infusions, paravertebral blocks, and systemic opioids for pain management and improvement of pulmonary mechanics. We report the use of a continuous erector spinae plane block (ESPB) via a peripheral nerve catheter for postoperative pain management of an 18-year-old patient who underwent complex aortic coarctation repair via lateral thoracotomy, aided by cardiopulmonary bypass. Continuous ESPB proved to be an acceptable alternative for postoperative pain control, producing a substantial multi-dermatomal sensory block, resulting in adequate pain control, reduced opioid consumption, and a potentially shorter hospital stay.

Erector spinae plane block versus paravertebral block for postoperative pain management in thoracic surgery: a systematic review and meta-analysis

INTRODUCTION

The 2018 guidelines for enhanced recovery in thoracic surgery recommend paravertebral block (PVB) for postoperative pain management. However, recent studies demonstrate that erector spinae plane block (ESPB) achieves similar postoperative pain control with reduced block-related complications.

EVIDENCE ACQUISITION

We conducted a meta-analysis of randomized controlled trials to evaluate the analgesic efficacy and safety of ESPB versus PVB for pain management after thoracic surgery. PubMed, Embase, and Scopus were searched through December 2022 (PROSPERO registration - CRD42023395593). Primary outcomes were postoperative pain scores, resting at 6, 12, 24, and 48 hours, and at movement at 24 and 48 hours. Secondary outcomes included opioid consumption at 24 and 48 hours, and incidence of postoperative nausea and vomiting or block-related complications in the first 48 hours.

EVIDENCE SYNTHESIS

Ten randomized control trials enrolling a total of 624 total patients were included. There were no significant differences in pain scores, resting or at movement, at any time points except reduced resting pain scores at 12 hours with PVB (mean difference [MD]) 0.60, 95% confidence interval [CI] 0.32 to 0.88). Opioid consumption demonstrated no significant differences at 24 hours; PVB reduced opioid consumption at 48 hours (MD 0.40, 95% CI -0.09 to 0.89). There were no significant differences in postoperative nausea or vomiting. ESPB exhibited a nonsignificant trend toward reduced cumulative block-related complications (risk difference [RD] 0.05, 95% CI -0.10 to 0.00).

CONCLUSIONS

Compared with PVB, ESPB is safe and demonstrates no clinically significant differences in pain management after thoracic surgery.

Relationship between injectate volume and disposition in erector spinae plane block: a cadaveric study

INTRODUCTION

Erector spinae plane (ESP) blocks can be used to provide analgesia following thoracoabdominal and lumbar spine surgical procedures. However, the influence of injectate volume and injection location on the spread of anesthetic with ESP blocks remain unclear.

METHODS

Ultrasound-guided ESP injections were performed on two fresh cadavers using a solution of iopamidol radiographic contrast, indocyanine green or methylene blue dye, and saline. The relationship between injectate volume and cephalocaudal spread was assessed using real-time fluoroscopic recordings after incremental ESP injections to the lumbar and thoracic region. Cadavers were then dissected to expose tissue staining and document the precise disposition of the dye within the ES muscle, paravertebral space, dorsal and ventral rami, and other relevant structures.

RESULTS

Larger injection volumes resulted in more extensive cephalocaudal spread in most cases, with fluoroscopic images revealing a small but direct relationship between injectate volume and contrast spread. Dissection reinforced the radiographic findings, with staining ventral to the ES muscle ranging from 4 to 7 paravertebral levels with injections of 30-40 mL vs 12-13 levels following injections of 60-80 mL. No spread of dye to the lamina, transverse processes, paravertebral space, epidural space, or pleura was observed following any injection.

CONCLUSIONS

Increased ESP injection volumes resulted in more extensive cephalocaudal spread, resulting in anesthetic spread to the dorsal rami and ventral ES muscle without involvement of the ventral rami or other anterior structures. Injection volumes of 30 mL may be optimal for ESP blocks requiring analgesia across 4-7 levels.

Benefits and risks of intermittent bolus erector spinae plane block through a catheter for patients after cardiac surgery through a lateral mini-thoracotomy: A propensity score matched retrospective cohort study

STUDY OBJECTIVE

A lateral mini-thoracotomy approach to cardiac surgery causes severe and complicated postoperative pain compared to the sternotomy approach. In this study we assessed the benefits and risks of intermittent bolus erector spinae plane block (ESPB) via a catheter for patients who underwent cardiac surgery through a lateral mini-thoracotomy.

DESIGN

A propensity score-matched retrospective cohort study.

SETTING

University hospital.

PATIENTS

452 consecutive patients that underwent cardiac surgery through a lateral mini-thoracotomy from 2018 to 2020.

INTERVENTIONS

Patients who received intermittent bolus ESPB through a catheter for 3 days (ESPB group, n = 93) were compared with patients who did not receive any regional anesthesia (Control group, n = 174) after propensity score matching.

MEASUREMENTS

The primary endpoint was postoperative in-hospital cumulative opioid consumption (calculated as oral morphine milligram equivalents, MME). The secondary outcomes were intraoperative sufentanil doses, therapeutic use of antiemetic, pulmonary infection (assessed using a modified clinical pulmonary infection score, CPIS), durations of ICU and hospital stays, and ESPB related/unrelated complications.

MAIN RESULTS

There is a lower oral MME in the ESPB group, 266 ± 126 mg in the ESPB group vs. 346 ± 105 mg in the control group (95% CI -113 to -46; P < 0.01). Fewer patients received therapeutic antiemetic agents in the ESPB group (30% vs. 42%, odds ratio 0.58; 95% CI 0.34 to 0.99; P = 0.04). The modified CPIS in the ESPB group is lower: 1.4 ± 0.9 vs. 2.0 ± 1.0 (95% CI -0.9 to -0.3; P < 0.01) on postoperative day 1; 1.6 ± 0.9 vs. 2.0 ± 0.9 (95% CI -0.7 to -0.2; P < 0.01) on postoperative day 2. The observed complications associated with ESPB include pneumothorax (1%), staxis around stomas (5%), hypotension (1%), catheter displacement (3%), and catheter obstruction (2%). None of the patients had any adverse outcomes.

CONCLUSION

Intermittent bolus ESPB is relatively safe and correlated with a reduction in the use of opioids and antiemetics for cardiac surgery through a lateral mini-thoracotomy.

Anatomical basis of erector spinae plane block: a dissection and histotopographic pilot study

Purpose

Erector spinae plane (ESP) block is an interfascial blockade used in different clinical scenarios. This study investigated the ventral extent of dye diffusion in ESP block.

Methods

The ultrasound-guided ESP block was bilaterally performed with an injection at the T5 vertebral level (21-Gauge, 50 mm needle), using diluted black tissue marking dye (20 mL; 1:4 ratio with standard saline solution) instead of local anesthetic on two fresh-frozen corpses within the body donation program of the University of Padova. Subsequently, the gross anatomical dissection was performed by a combined posterior plus anterior approach, and the histotopographic examination completed.

Results

Macroscopically by gross anatomical dissection, the dye spreading ranged on the dorsal side of the chest from T2/3 to T10/11 with an extension up to 10 cm laterally, and on the ventral side of the chest from T2/3–T9/10. Microscopically by histotopographic examination, the dye diffused ventrally to the intercostal spaces (2–3 and 5–6 spaces on the right and left, respectively) by following the blood vessels coupled to the dorsal nerve passing through the costotransverse foramen.

Conclusions

The anterior pathway of dye diffusion from the site of injection within the erector spinae muscle group during an ESP block seems to follow the blood vessels and dorsal rami of spinal nerves, suggesting the passing through the costotransverse foramen to reach the anterior paravertebral space and the intercostal nerves. These findings display an anterior histotopographic diffusion of dye resembling a paravertebral block.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00540-020-02881-w.