Comparative analgesic efficacy of erector spinae plane block versus quadratus lumborum block in laparoscopic renal cancer surgery: a double-blind randomized trial

Introduction

Kidney cancer is increasingly prevalent worldwide, and laparoscopic nephrectomy has become a standard treatment due to its minimally invasive nature and potential for faster recovery (1,2). Nevertheless, moderate to severe postoperative pain remains common, potentially affecting patient outcomes and prolonging hospitalization (3,4).

Effective pain management is essential after laparoscopic renal surgery. While multimodal approaches incorporating opioids and regional anesthesia are widely used, concerns regarding opioid-related side effects and the risks associated with techniques such as epidural and paravertebral blocks have prompted interest in alternative regional blocks (5-9). Ultrasound-guided erector spinae plane block (ESPB) and quadratus lumborum block (QLB) have gained attention as less invasive options that may offer favorable analgesic profiles (10-13).

However, evidence directly comparing ESPB and QLB in the context of laparoscopic renal cancer surgery remains limited. This study was designed to compare the efficacy and clinical benefits of ESPB and QLB in patients undergoing laparoscopic nephrectomy, with a focus on early postoperative opioid use, pain control, recovery quality, and hospital stay. We present this article in accordance with the CONSORT reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-71/rc).

Methods

Study design

This single-center, double-blind, randomized controlled trial was registered with the Chinese Clinical Trial Registry (ChiCTR2300074743) and adhered to all applicable guidelines and regulations.

Participants

Patients were prospectively recruited from the Department of Anesthesiology, Sichuan Provincial People’s Hospital (Chengdu, China), between August 16, 2023, and October 30, 2023. Eligible participants were aged 18–70 years, had a body mass index (BMI) of 18–30 kg/m², and were classified as American Society of Anesthesiologists (ASA) grades (14-16) I–II. Exclusion criteria included contraindications for laparoscopic nephrectomy (such as elevated preoperative intracranial pressure, severe hypertension, motion sickness, glaucoma, nausea-related conditions, and patients requiring changes in surgical procedures) and for regional nerve block (including platelet or coagulation abnormalities, local anesthetic allergies, puncture site infections, and severe dysfunction of major organs). Patients with chronic opioid addiction or long-term use of analgesics were also excluded to improve the accuracy of postoperative pain assessment.

Randomization and blinding

Patients were randomized in a 1:1 ratio into the ESPB group (Group E) or the QLB group (Group Q) using a computer-generated randomization list (SPSS 25.0, IBM, Chicago, IL, USA). Opaque sealed envelopes containing group assignments were prepared by an uninvolved researcher. An independent anesthesiologist received the allocation envelope 1 hour before surgery and administered the designated nerve block under ultrasound guidance. A separate anesthesiologist managed general anesthesia and intraoperative care. Blinding was maintained for the surgical team, nursing staff, data collectors, and statisticians.

Interventions:

• ESPB: ultrasound-guided ESPB was performed with a 22-gauge nerve block needle, injecting 25 mL of 0.4% ropivacaine between the transverse process and erector spinae muscle.
• QLB: ultrasound-guided QLB was conducted using a low-frequency ultrasound probe to guide a 22-gauge needle, injecting 25 mL of 0.4% ropivacaine posterior to the quadratus lumborum muscle.

Outcome measures:

• Primary outcome: total morphine consumption within 6 hours post-surgery.
• Secondary outcomes: these included block procedure time, nerve block puncture depth, intraoperative mean arterial pressure (MAP) and heart rate (HR) at various time points, Numerical Rating Scale (NRS) (17,18) pain scores, the 15-item Quality of Recovery scale (QoR-15) scores (19-21), complications related to the nerve block, time to first ambulation, and hospital stay duration.

Ethics

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of Sichuan Academy of Medical Sciences (Sichuan Provincial People’s Hospital) (2023 No. 24-1) and informed consent was obtained from all individual participants. Patient enrollment and allocation were illustrated using a CONSORT flow diagram (Figure 1).

Figure 1 CONSORT flow diagram for patient enrollment and allocation. Flow diagram illustrating the enrollment, randomization, allocation, and final inclusion of patients in the study. A total of 60 patients were screened, of whom 54 were included in the final analysis after exclusions. ESPB, erector spinae plane block; QLB, quadratus lumborum block.

Surgical technique

All procedures were conducted by a consistent surgical team utilizing retroperitoneal or transperitoneal approaches.

Retroperitoneal approach

Patients were placed in the lateral decubitus position. Three trocar placement sites (ports) were established: one along the posterior axillary line below the 12th rib, a second 2 cm above the iliac crest along the mid-axillary line, and a third at the anterior axillary line below the costal margin. For radical nephrectomy, the surgical specimen was extracted either via a low transverse Pfannenstiel incision or by extending a port-site incision, according to the surgeon’s preference and intraoperative conditions.

Transperitoneal approach

Patients were positioned semi-obliquely. Three or four trocars were inserted between the umbilicus and xiphoid process, extending from the midline to the anterior axillary line. Pneumoperitoneum pressure was maintained at 12–16 mmHg throughout the procedure.

Block procedures

Peripheral vein access was established, and continuous monitoring of HR, blood pressure, electrocardiogram (ECG), peripheral oxygen saturation (SpO₂), and invasive arterial pressure was conducted. All blocks were performed by an experienced anesthesiologist using an ultrasound machine (M-Turbo, FUJIFILM SonoSite, USA) with a 22-gauge, 80-mm nerve block needle (B. Braun Meisungen AG, Germany). All nerve blocks were performed unilaterally on the surgical side.

Ultrasound-guided ESPB

The patient was placed in the lateral position. The ultrasound probe was moved from the 12th rib to the T10 transverse process. The needle was advanced out-of-plane to the area between the transverse process and erector spinae muscle. After confirming needle placement with 1–2 mL of saline, 25 mL of 0.4% ropivacaine was injected (Figure 2).

Figure 2 Sonoanatomy and needle approach for ultrasound-guided ESPB. (A) Ultrasound image at the T10 TP level, identifying key anatomical landmarks: LD, ESM, and adjacent transverse processes (T9, T10, T11). The white arrow indicates the target fascial plane between the erector spinae muscle and the T10 transverse process, where local anesthetic is intended to be injected. (B) After needle placement (typically using the out-of-plane approach), local anesthetic is visualized spreading in the fascial plane deep to the ESM and superficial to the transverse process. The solid white line outlines the distribution of local anesthetic. The white arrow points to the spread of local anesthetic within the fascial plane. (C) Schematic illustration of the ESPB, showing in-plane needle trajectory targeting the fascial plane between the erector spinae muscle and the T10 transverse process. ESM, erector spinae muscle; ESPB, erector spinae plane block; LD, latissimus dorsi; TP, transverse process.

Ultrasound-guided QLB

The patient was positioned laterally with the affected side up. After skin disinfection, a low-frequency ultrasound probe was placed axially at the L3 level and moved posteriorly to visualize the quadratus lumborum and psoas muscles. A needle was inserted in-plane from dorsal to ventral, and after confirming placement with 1–2 mL of saline, 25 mL of 0.4% ropivacaine was injected near the lumbar fascia triangle (Figure 3). We chose the QLB-II (posterior) approach because its block range (T7–L1) is well-suited for the typical incision levels (T7–T12) and kidney innervation (T9–L1) in laparoscopic nephrectomy. Compared to QLB-III, QLB-II is less likely to cause lower limb weakness, which is important for early postoperative mobilization. Therefore, QLB-II was selected to better match surgical needs and enhance recovery.

Figure 3 Sonoanatomy and needle approach for ultrasound-guided QLB-II. (A) Ultrasound image at the L3 vertebral level shows relevant anatomy: LD, QLM, ESM, TP, and PM. The white arrow indicates the QLM, the primary anatomical target for the QLB-II block. (B) After in-plane needle insertion, local anesthetic is visualized spreading at the fascial plane posterior to the QLM and lateral to the ESM. The white arrow points to the site of local anesthetic injection and its spread along the fascial plane. The white outline shows the distribution of local anesthetic. (C) Schematic illustration demonstrating the ultrasound probe and needle placement for QLB-II. The needle targets the fascial plane between the quadratus lumborum and the erector spinae muscles, corresponding to the LIFT. The local anesthetic spreads along this plane, providing effective analgesia. ESM, erector spinae muscle; LD, latissimus dorsi; LIFT, lumbar interfascial triangle; PM, psoas major muscle; QLB, quadratus lumborum block; QLM, quadratus lumborum muscle; TP, transverse process.

Nerve block assessment

Thirty minutes after the procedure, the block range was assessed by a different anesthesiologist who was blinded to group allocation and not involved in the nerve block procedures, using the alcohol cold extinction method. Reduced or absent cold sensation compared to unblocked areas indicated successful nerve block. Block failure was defined as normal sensation in the surgical area.

Perioperative management

Anesthesia management

Standard intraoperative monitoring included ECG, SpO₂, invasive arterial pressure, electroencephalography (EEG), and body temperature. General anesthesia was induced with midazolam (0.04 mg/kg), sufentanil (0.3 µg/kg), cisatracurium (0.15 mg/kg), and propofol (2 mg/kg). Anesthesia was maintained with remifentanil (0.1–0.2 µg/kg/min) and propofol (4–12 mg/kg/h), targeting a cerebral state index (CSI) of 40–60. Medications were titrated to maintain MAP and HR within ±20% of baseline values. Postoperative pain and nausea were managed with sufentanil (0.05 µg/kg) and tropisetron (5 mg), respectively.

Intraoperative treatment

Hypotension (MAP <20% below baseline) was treated with ephedrine [6 mg intravenous (IV)] or norepinephrine (50 µg IV). Hypertension (MAP >20% above baseline) was managed with remifentanil (40 µg), propofol (30 mg), or nicardipine (0.1 mg IV). Bradycardia (HR <50 bpm) was treated with atropine (0.3 mg IV), and tachycardia (HR >100 bpm) with esmolol (10 mg IV).

Analgesia management

Patients were trained to use the Numeric Rating Scale (NRS) and Patient-Controlled Intravenous Analgesia (PCIA). Analgesia was administered via a pump containing morphine (50 mg), tropisetron (5 mg), and saline (100 mL), with a bolus dose of 4 mL and a 15-minute lockout interval. For inadequate pain relief (NRS ≥4), tramadol (100 mg) or dezocine (5 mg) was administered as rescue analgesia.

Outcome measurements

Primary outcome: cumulative morphine consumption within 6 hours post-surgery.

Secondary outcomes: these included nerve block duration, puncture depth, MAP and HR at defined time points (T0–T4), intraoperative drug use, operation and anesthesia times, NRS pain scores, QoR-15 scores at 24 and 48 hours, nerve block complications, time to first ambulation and exhaust, and length of hospital stay.

Sample size calculation

A preliminary pilot study (QLB: 6.63±4.61 mg; ESPB: 3.51±3.25 mg) guided the sample size calculation using G*Power software (version 3.1.9.7, Germany). A total of 54 patients (27 per group) was required to achieve 80% power (α=0.05) with an effect size of 0.78. To account for a 10% dropout rate, the final sample size was increased to 60.

Statistical analysis

Data analysis was conducted using SPSS 25.0. Normally distributed data were expressed as mean ± standard deviation and compared using independent t-tests or Welch’s t-test for unequal variances. Non-normally distributed data were summarized as medians (interquartile range) and analyzed with the Mann-Whitney U test. Categorical variables were reported as frequencies or percentages and compared using Chi-squared or Fisher’s exact tests when necessary. Statistical significance was set at P<0.05.

Results

A total of 60 patients were initially enrolled in the study. Six patients were excluded due to various reasons: 2 refused participation, 2 surgeries were canceled, 1 required conversion to open surgery, and 1 experienced nerve block failure. The final analysis included 54 patients, with 27 in each group (QLB and ESPB) (Figure 1).

Baseline characteristics

The baseline demographic and perioperative variables, including age, sex, BMI, ASA classification, hypertension, history of surgery, surgical site, operative approach, excision extension, preoperative QoR-15 score, procedure and anesthesia duration, and intraoperative drug use, were comparable between the ESPB and QLB groups, with no statistically significant differences in any stratified variable (all P>0.05; Table 1).

Primary outcome: cumulative morphine consumption

Cumulative morphine consumption within the first 6 hours post-surgery was significantly lower in the ESPB group compared to the QLB group [4.11±4.05 vs. 6.63±4.61 mg; mean difference: 2.52, 95% confidence interval (CI): 0.15–4.89; P=0.04]. However, no significant differences were observed at 24 or 48 hours postoperatively (Table 2).

Secondary outcomes

Morphine pump activations

Patients in the ESPB group activated their morphine pumps significantly fewer times than those in the QLB group at both 6 hours (1.67±1.44 vs. 3.37±2.22 times; P=0.02) and 24 hours (4.52±2.85 vs. 7.04±4.47 times; P=0.02) (Table 2).

Pain scores

Resting NRS pain scores were significantly lower in the ESPB group at 0.5 hours postoperatively (1.04±0.94 vs. 1.74±1.20; P<0.05), while no significant differences were found at later time points (Figure 4A). No differences were observed in coughing NRS pain scores at any time point (Figure 4B).

Figure 4 Postoperative NRS pain scores comparison between the ESPB and QLB groups. (A) Resting NRS pain scores at 0.5, 6, 24, and 48 hours postoperatively. (B) Coughing NRS pain scores at 0.5, 6, 24, and 48 hours postoperatively. Values are expressed as mean ± standard deviation. Significant differences (*, P<0.05) are indicated between the ESPB and QLB groups. ESPB, erector spinae plane block; NRS, Numeric Rating Scale; QLB, quadratus lumborum block.

Hemodynamic stability

The ESPB group had significantly lower MAP at T1 (5 minutes before skin incision) compared to the QLB group (P<0.05). MAP values at other time points and HRs across all time points were similar between the groups (Figures 5A,5B).

Figure 5 Hemodynamic parameters at different perioperative time points. (A) MAP measured at T0 (anesthesia preparation room), T1 (5 minutes before incision), T2 (5 minutes after incision), T3 (5 minutes after extubation), and T4 (on leaving PACU). (B) HR recorded at the same time points. Significant differences (*, P<0.05) between groups are indicated. HR, heart rate; MAP, mean arterial pressure; PACU, postanesthesia care unit.

Intraoperative vasoactive drug usage

There were no significant differences between the two groups in the usage of vasoactive medications, including ephedrine, neo-synephrine, esmolol, nicardipine, or atropine (Table 3).

Nerve block procedure

The ESPB group required a shorter time for the nerve block procedure (3.12±0.28 vs. 3.41±1.01 min; P<0.001) and had a slightly shallower puncture depth (2.09±0.68 vs. 2.14±0.39 cm; P<0.001) compared to the QLB group (Table 4).

QoR-15

The ESPB group achieved significantly higher QoR-15 scores at both 24 hours (124.78±3.40 vs. 118.85±6.77; mean difference: 7.59, 95% CI: 4.52–10.67; P<0.05) and 48 hours postoperatively (Figure 6).

Figure 6 Comparison of QoR-15 scores between the ESPB and QLB groups. QoR-15 scores at 24 and 48 hours postoperatively. Scores are expressed as mean ± standard deviation. The ESPB group exhibited significantly higher QoR-15 scores compared to the QLB group (*, P<0.05). ESPB, erector spinae plane block; QLB, quadratus lumborum block; QoR-15, the 15-item Quality of Recovery scale.

Postoperative complications

No significant nerve block-related complications, such as hematoma, infection, local anesthetic toxicity, or respiratory depression, were observed in either group (Table 5). While the ESPB group had a slightly lower incidence of nausea, the difference was not statistically significant (P>0.05).

Postoperative recovery time

The time to first ambulation and first flatus did not differ significantly between groups. However, the ESPB group had a significantly shorter postoperative hospital stay compared to the QLB group (162.02±96.53 vs. 240.47±149.72 hours; P=0.03) (Table 6).

Discussion

This randomized controlled trial compared ultrasound-guided ESPB and QLB in 54 patients undergoing laparoscopic nephrectomy (LN). The results demonstrated that ESPB had advantages over QLB, including a shorter and shallower puncture process, reduced cumulative morphine consumption at 6 hours postoperatively, fewer morphine pump activations, lower early postoperative pain scores, improved recovery quality (QoR-15 scores at 24 and 48 hours), and shorter hospital stays. While ESPB was associated with a transient reduction in MAP at T1, this did not necessitate increased use of intraoperative vasoactive medications. Although the ESPB group demonstrated significantly reduced morphine consumption within the first 6 postoperative hours, differences at 24 and 48 hours were not statistically significant. However, the mean morphine consumption in the ESPB group remained lower than in the QLB group at both 24 hours (10.37±7.75 vs. 13.59±7.56 mg) and 48 hours (13.78±9.99 vs. 19.44±11.12 mg). These numerical differences (mean differences of 3.22 and 5.66 mg, respectively) may still be clinically relevant, but the present sample size may have limited the power to detect statistically significant differences at later time points. Further studies with larger sample sizes are needed to clarify whether these trends translate into meaningful long-term benefits.

ESPB in clinical practice

First introduced by Forero et al. in 2016 for managing neuropathic pain (22), ESPB has gained recognition as an effective nerve block in various surgical settings, including laparoscopic nephrectomy. Studies comparing ESPB with thoracic paravertebral block (TPVB) have shown non-inferiority for postoperative analgesia (23-25). Additionally, Sahin et al. reported significant reductions in pain scores, opioid consumption, and enhanced recovery quality with ESPB at the T10 level in LN patients (26).

QLB approaches and challenges

QLB, developed by Blanco in 2007 (27), has evolved into multiple techniques, including QLB-I (lateral), QLB-II (posterior), QLB-III (anterior), and QLB-IV (muscular) (28). This study utilized QLB-II, targeting the lumbar fascia triangle for T7-L1 coverage. Despite advantages such as a superficial injection site and clear ultrasound imaging, QLB’s efficacy in reducing opioid use has shown mixed results, with some studies reporting improvements in analgesia and recovery within 24–48 hours (29,30). The variability in quadratus lumborum anatomy due to factors like age, obesity, and individual anatomical differences can complicate QLB administration, making ESPB a more consistent and reliable choice. In our study, all nerve block procedures were performed by the same experienced anesthesiologist using a standardized protocol and identical ultrasound equipment, which minimized operator-related variability and allowed a more direct comparison of the true clinical efficacy between ESPB and QLB.

Hypotension and local anesthetic spread

The ESPB group exhibited lower MAP at T1, likely due to extensive epidural spread of the local anesthetic, as supported by previous studies (31,32). Research indicates that ESPB can result in the diffusion of anesthetic to paravertebral, foraminal, and epidural spaces, potentially leading to hypotension. Conversely, QLB’s spread is typically less extensive and more variable (33,34), which may explain the observed differences in MAP.

Superior early analgesia with ESPB

Consistent with other studies, ESPB demonstrated better early postoperative analgesia than QLB. For example, Aygun et al. reported significantly lower pain scores with ESPB during the first postoperative hour compared to QLB, despite similar overall opioid consumption (35). In cesarean section patients, ESPB and QLB-II were found to have comparable analgesic effects, likely due to overlapping influences from subarachnoid blocks and other interventions (36).

Recovery quality and hospital stay

The ESPB group’s higher QoR-15 scores at 24 and 48 hours align with findings by Moorthy et al., who observed superior recovery quality with ESPB compared to TPVB after thoracic surgery (37). Early pain control with ESPB appears to positively impact overall recovery quality (38). Additionally, ESPB was associated with a shorter hospital stay, consistent with previous research by Yao et al. (39), likely reflecting improved pain management and faster recovery.

Safety profile

Both ESPB and QLB were found to be safe, with no significant nerve block-related complications observed. Rare adverse events, such as lower limb weakness and referred pain, have been reported in other studies (40,41), but none occurred in this trial. Postoperative recovery milestones, including time to ambulation and first flatus, were similar between groups, highlighting the comparable safety and efficacy of both techniques.

Limitations

This study has several limitations. First, the effectiveness of the blocks was evaluated based on the regression of cold sensation, which may not fully capture the complete extent of the block. Additionally, time constraints prior to surgery limited the thorough assessment of the block plane in some patients. Second, variations in early mobilization protocols for patients undergoing radical versus partial nephrectomy may have influenced recovery-related outcomes. Third, this was a single-center study with a relatively small sample size, potentially limiting the generalizability of the results. Larger, multicenter studies are warranted to validate and extend our findings. Our findings should be interpreted as exploratory and hypothesis-generating, warranting confirmation in larger, multicenter trials. Lastly, the absence of a control group without nerve blocks precludes the ability to evaluate the absolute benefits of each block technique.

Conclusions

ESPB demonstrates notable advantages over QLB in improving analgesic efficacy and recovery outcomes after laparoscopic nephrectomy, including opioid-sparing effects and shorter hospital stays. Future research should focus on optimizing the concentration and dosage of local anesthetics to further enhance the effectiveness of ESPB. In summary, this study provides preliminary evidence on the comparative benefits of ESPB and QLB for laparoscopic renal cancer surgery, but larger studies are required to confirm these results.

Acknowledgments

We thank Dr. Cassidy Allison at the Texas Medical Center for her valuable assistance in editing the English language of our manuscript.

Footnote

Reporting Checklist: The authors have completed the CONSORT reporting checklist. Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-71/rc

Trial Protocol: Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-71/tp

Data Sharing Statement: Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-71/dss

Peer Review File: Available at https://tau.amegroups.com/article/view/10.21037/tau-2025-71/prf

Funding: This research was supported by the Sichuan Science and Technology Program (Grant No. 2023YFS0193 to M.Z.), the Young Talents Project of Sichuan Provincial People’s Hospital (Grant No. 2022QN50), the Sichuan Provincial People’s Hospital Young Talent Fund (Grant No. 2022QN07 to M.Z.), and the MedicoEngineering Cooperation Funds from the University of Electronic Science and Technology of China (Grant No. ZYGX2021YGLH221 to M.Z.).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tau.amegroups.com/article/view/10.21037/tau-2025-71/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of Sichuan Academy of Medical Sciences (Sichuan Provincial People’s Hospital) (2023 No. 24-1) and informed consent was obtained from all individual participants.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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