The erector spinae plane block for analgesia after lumbar spine surgery: A systematic review

Abstract

Objective

To evaluate the available evidence for the utility of Erector Spinae Plane blocks (ESPB) after Lumbar surgery

Methods

Databases were searched until December 20, 2020. ESPB was utilized as a MesH term and terms such as: lumbar spinal stenosis, spondylolisthesis, decompression and lumbar spine surgery.

Results

Studies demonstrate that ESPB are consistently found to be a safe and effective method of analgesia after lumbar surgery, with limited adverse effects

Conclusion

ESPB appear to be an effective method to relieve pain after lumbar surgery. More RCTs will be needed to further investigate the clinical effectiveness of this intervention

1. Introduction

Acute postsurgical pain following lumbar surgeries is frequently detrimental in a patient's recovery and quality of life.¹ Furthermore, surgical interventions for disk herniations, internal disk disruptions, spinal stenosis, and additional degenerative spinal pathologies have been on the rise.² Clinical use of patient-controlled modalities for acute postoperative pain such as IV patient-controlled analgesia (PCA) or oral PCA are common, but have limitations associated with the activation of μ-opioid receptors and the side effects related to this.³ Epidural analgesia has been regarded as the gold standard for postoperative pain management, but is invasive, costly, and can have adverse effects.⁴ With the rise of surgical interventions and a risk of postoperative pain developing into chronic pain, it is imperative to investigate new avenues of analgesia.

One such avenue is the erector spinae plane block (ESPB), a novel analgesic technique first described in 2016 by Forero et al.⁵ Although the mechanism of action of the ESPB is unknown, a proposed mechanism is via blockade of the dorsal and ventral rami of thoracic/lumbar spinal nerves.⁶ ESPB has been used as analgesia in rib fractures and other thoracic procedures as well as in painful conditions of the shoulder, and more areas associated with the erector spinae muscle.⁷ ESPB has the potential to increase range of motion and profoundly decrease pain. Forero and associates reported ESPB displayed a detectable sensory block in chronic shoulder pain with no motor block, allowing for clinical analgesia that outlasted the expected duration.⁸ Following a pediatric oncological thoracic surgery, ESPB was conducted because of its ease compared to other epidural interventions and provided wound analgesia.⁹ Similarly, ESPB relieved postoperative pain following lumbosacral spine surgery and drastically decreased postoperative opioid requirements.¹⁰ With a reduction in analgesic drugs following operations, patient recovery is improved and accelerated while reducing the costs of hospitalization and readmittance.

The purpose of this manuscript is the thorough and recent review of a new potential treatment for pain after lumbar surgery. To date, there is one systematic review completed on this topic.¹¹ Since this systematic review, there have been more studies conducted that can shed light on the mechanism, efficacy, and practicality of ESPB following lumbar spine surgery. The addition of these RCTs warrants inclusion in an updated systematic review.

2. Materials and methods

2.1. Search strategy

We performed a systematic review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. PubMed, EMBASE, Cochrane library, and ClinicalTrial.gov databases were searched for this systematic review. MeSH terms and free-text words utilized were “ESP block”, “erector spinae plane block”, and “lumbar surgery” (Fig. 1). The window of time of searching was from inception through December 18, 2020.

Fig. 1.

Flow chart showing the identification and selection of the articles for the systematic review.

2.2. Screening of studies

All accumulated titles were screened for duplicates by 2 reviewers (JMR, BH) and decided which manuscripts were eligible for inclusion. Disagreements between authors were discussed and resolved by the remaining authors. Overall consensus was achieved for final eligibility (Table 1).

Table 1.

Qualitative evaluation of the studies that assessed postoperative analgesia of ESPB on lumbar spine surgery.

Author	Country	Study Design	Study Size	Intervention Performed	ESPB	Outcome	Side Effect	Follow-Up Time	Conclusion
Ciftci et al. (2020)	Turkey	RCT	90	Lumbar Discectomy	20 mL of .25% bupivacaine bilaterally. Single injection at L3.	Visual Analog Scale (VAS), amount of fentanyl delivered by IV.	None	24 h	ESPB provides adequate analgesia after lumbar spinal surgery. However, not superior to modified thoracolumbar interfascial plane (mTLIP) block
Eskin et al. (2020)	Turkey	RCT	120	Lumbar Spinal Surgery	20 mL of .25% bupivacaine bilaterally. Single injection at vertebrae that was midpoint of incision.	VAS, rescue analgesia, amount of tramadol delivered by PCA	None	48 h	ESPB provides effective pain relief after lumbar spinal surgery. ESPB is superior to MTP in the first 24 h post-operatively.
Kianpour et al. (2020)	USA	Case Series	2	Lumbar Spinal Fusion	30 mL of .375% bupivacaine bilaterally. Single injection at T-10 postoperatively as rescue analgesia.	Numerical Rating Scale (NRS)	None	24 h	ESPB provides adequate analgesia to manage uncontrolled acute post-operative pain from lumbar spinal fusion surgery.
Zhang et al. (2020)	China	RCT	60	Lumbar Spinal Fusion	20 mL of .4% ropivacaine bilaterally. Single injection at L3.	NRS first 12 h post-op NRS at rest and movement, amount of opioid delivered by	N/V and dizziness in both control group and ESPB group with no statistical significance.	48 h	ESPB decrease pain scores and post-operative opioid consumption. May be effective component of multimodal analgesia in patients undergoing lumbar spinal fusion surgery.
Canturk et al. (2019)	Turkey	Case Report	1	Lumbar Spinal Fusion	10 mL bupivicaine 0.25% and 10 mL prilocaine 1% bilaterally. Single	NRS, amount of opioid delivered by	None	24 h	ESPB provides long lasting analgesic effects after lumbar surgery. Assists in early mobilization and adherence to rehabilitation programs.
De Lara et al. (2019)	Spain	Case Series	8	Lumbar Spinal Fusion	20 mL ropivacaine 0.2% bilaterally. Single injection at L4.	VAS, rescue analgesia, opioid consumption	None	48 h	ESPB contribute to pain control in the first 48 h after lumbar spinal fusion surgery. They also reduce the consumption of opioids during the first 48 h after lumbar spinal fusion.
Singh et al. (2019)	India	Case Series	7	Surgery for PLID or Lumbar Stenosis	20 mL bupivacaine .25% bilaterally. Single injection at T10.	NRS, rescue analgesia	None	10 h	ESPB block is effective and safe in managing postoperative pain after lumbar spine surgery with a duration of 6–8 h.
Almeida et al. (2019)	Portugal	Case Report	1	L2-S1 Spine Fusion	20 mL ropivacaine 0.2% bilaterally was maintained	NRS	None	48 h	ESPB blocks may be administered away from the surgical site as a method to contribute to pain control after lumbar spinal fusion.
Singh et al. (2019)	India	RCT	40	Elective Lumbar Spinal Surgery	20 mL bupivacaine 0.5% bilaterally. Single injection at T10.	NRS, opioid consumption, patient satisfaction	Severe nausea/vomiting in 2 control group patients.	24 h	ESPB improves postoperative pain and patient satisfaction in postoperative lumbar spine surgery patients. ESPB also reduced postoperative opioid consumption.
Ueshima et al. (2019)	Japan	Retrospective study	41	Lumbar Spinal Surgery	20 mL levobupivacaine 0.375% bilaterally. Single injection at target vertebral	NRS, analgesia consumption, complications.	None	24 h	ESPB is effective method of pain control until post-operative day 2 following lumbar laminoplasty.
Yayik Et al (2019)	Turkey	RCT	60	Open Lumbar Decompression	20 mL bupivacaine 0.25% bilaterally, Single injection at L3	VAS, opioid consumption, rescue analgesia, opioid-related side	None	24 h	ESPB is effective in managing postoperative pain in patients who have open lumbar decompression surgery. ESPB block reduces postoperative opioid consumption.
Brandao et al. (2018)	Portugal	Case Report	1	Lumbar Spinal Surgery	15 mL ropivacaine 0.375% bilaterally. Single injection at L4	Pain scores, analgesia consumption.	None	48 h	ESPB is effective in managing pain post-operatively. ESPB block decreased need for pain related opioids. ESPB block also allowed for less painful ambulation.
Calandese et al. (2018)	Italy	Case Report	1	Anterior Thoracolumbar spine surgery	40 mL of 0.25% levobupivacaine and 2 mL (8 mg) of dexamethasone was injected bilaterally. Single injection at T10.	NRS scores, analgesia consumption.	None	24 h	ESPB can provide effective postoperative pain management as part of multimodal plan in patients after anterior thoracolumbar spine surgery
Cesur et al. (2018)	Turkey	Case Series	5	Lumbar surgery	20 mL bupivacaine 0.25% and lidocaine 1% bilaterally. Single-injection at T12	NRS scores, analgesia consumption.	None	24 h	ESPB block is safe and effective in reducing postoperative pai in lumbar spine surgeries. Also reduced opioid consumption.
Melvin et al. (2018)	USA	Case Series	6	Lumbosacral Surgery	10 mL .2% ropivacaine via continuous infusion at T10, T12. Varying mL.375% bupivacaine bilaterally. Single injection at T12.	NRS scores, analgesia consumption.	None	72 h	ESPB block is effective in managing postoperative pain as part of a multi-modal, opioid free regimen in lumbosacral spine surgery. Recommend increased catheter use in patients with history of pain issues to decrease use of opioids. Also to decrease escalation of opioid doses in patients with complex pain history.

2.3. Inclusion criteria

The inclusion criteria for our desired systematic review was the following: 1) Case reports, case series, retrospective cohorts, or randomized controlled trials (RCTs); 2) that included human patients undergoing lumbar spine surgery; 3) who received a pre-operative erector spinae plane block. Additionally, we included only articles published in English for the sake of this systematic review.

2.4. Data collection

Of the included manuscripts for the literature review, we collected the year of publication, country of authorship, type of study, type of block (single shot, continuous, intermitted bolus), age of patient, medication used for block, side effects or adverse events, VAS scores, and overall patient satisfaction.

2.5. Assessment of study quality

The quality of randomized control trials included in the study was evaluated utilizing the modified Cochrane risk of bias assessment tool. In total, 5 RCTs were found that met the inclusion criteria. Each RCT was evaluated for its random sequence generation, allocation concealment, blinding to participants, blinding of outcomes, incomplete outcome data, and selective data reporting. These factors were utilized in order to evaluate each study's selection bias, performance bias, detection bias, attrition bias, and reporting bias. Two authors, JMR and BH, evaluated each of the RCTs for the described variables. Each source of bias was graded as low/unclear/high risk. The data was inputted into Revman 5.4 (The Cochrane Collaboration, 2020) for figure generation and analysis (Fig. 2, Fig. 3).

Fig. 2.

Risk of Bias Summary of included RCTs.

Fig. 3.

Risk of bias graph for included RCTs.

3. Results

3.1. Study identification

In total, 15 studies were identified for inclusion in this systematic review with 5 of them being RCTs, 5 case series, 4 case reports, and one retrospective study. 443 patients were identified in total within these included studies. The follow up time for these manuscripts ranged from 10 h to 72 h post-operatively. All but one manuscript utilized ESPB in an injection fashion. Of the 15 manuscripts, 12 performed bilateral single ESPBB injections for analgesic relief. 2 studies utilizing unilateral single injection. 1 article reported post op pain relief through continuous peripheral nerve catheterizations. The most frequent quantity of medication utilized for the block was 20 mL of anesthetic on each side of the spine.

The most frequently utilized medications for pain relief were bupivacaine, lidocaine, and ropivicaine of differing concentrations. All RCTs found a significant reduction in postoperative VAS scores and postoperative pain medication consumed. Per the included studies, ESPB reported no adverse effects or side effects in all but one study, in which two patients developed severe nausea and vomiting. There were no operation-related adverse events that occurred.

4. Discussion

Spine surgery, particularly lumbar surgery, is increasing in frequency across the United States and the world. In the United States, there has been a significant increase in the number of lumbar fusion surgeries from the early 2000s to 2015.¹² This phenomenon is not only seen in the United States, but also in Europe and Asia.^13,14 With the overall increase in prevalence of spine surgery, there is a similar trend identified in the prescription of opioids.¹⁵ It is well recognized that spine surgery is a driving force for opioid consumption. Kalakoti et al. retrospectively analyzed 26,553 patients who underwent lumbar spine surgery, with many of them requiring narcotics beyond one month post-operatively.¹⁵ Given the current opioid epidemic, finding alternative methods to minimize post-operative opioid consumption has become a primary goal of healthcare systems across the world.

More recently, erector Spinae Plane blocks are finding efficacy in multiple surgical subspecialties. ESPB utility has been explored in the field of bariatrics, joint arthroplasty, breast surgery, and cholecystectomy.16, 17, 18, 19 In the world of spine surgery, ESPB have been explored as a way to minimize pain after surgery. The articles included in this study were specific to lumbar spine surgery. Different medications were utilized in different studies, with ropivicaine, bupivacaine, and lidocaine utilized most commonly. Though there were no investigations to explore the differences between each of these medications, this systematic review indicates that all appear to be effective as a means for analgesia after lumbar spine surgery. The duration of pain relief was investigated in these studies from 4 to 72 h, which differs largely based on the type of anesthetic used, volume injected, and the bilateral vs unilateral injection site.

The volume of anesthetic injected in these studies ranged from 20 to 40 mL and varied in a unilateral or bilateral injection modality. Regardless, nearly all studies reported no adverse events or side effects with the injections. Nausea and vomiting was the only reported outcome described by two studies, Zhang et al. and Singh et al. Although a thorough side effect profile was not executed in these studies, the data acquired through this systematic review indicates an overall safe trend for the use of ESPB prior to lumbar spine surgery.

There are some limitations to this systematic review. Firstly, the overall number of RCTs is low, with only 5 RCTs. Additionally, the most common outcome assessed was VAS scores perceived by patients. No consistent spine patient-reported outcome studies were utilized in the listed RCTs. Furthermore, narcotic consumption was not consistently reported in these RCTs which is an important variable to consider with the ESPBintervention. Also, the medications used for the block differed between RCTs, with some medications havinga longer half-life than those utilized in other studies. This may alter the duration of the efficacy of the block. Finally, the studies included in this systematic review were strictly for “lumbar spine surgery,” which includes multiple different lumbar spine surgeries. This was not standardized between the studies. Therefore, one may infer that a laminectomy or bony decompression may require more narcotics post op than a lumbar discectomy. However, given the limited number of RCTs in the literature, this was not feasible for this investigation. Nonetheless, this remains the most comprehensive and up-to-date systematic review on this current topic. While the patients included in this review, 443 patients in total, is not insignificant, it still represents a small number of the patients undergoing lumbar spine surgery around the world.

5. Conclusion

Though there continues to be limited studies regarding the effectiveness of the ESPB for lumbar spine surgery, recent RCTs indicate that this may be a promising means of relieving pain after spine surgery. There continues to be growing evidence for the widespread utilization of ESPB for lumbar spine surgery. Further RCTs are needed to quantify this method of treatment for pain.