Postoperative Analgesic Efficacy of the Ultrasound-Guided Erector Spinae Plane Block in Patients Undergoing Lumbar Spinal Decompression Surgery: A Randomized Controlled Study

BACKGROUND

Spinal surgery is a procedure that causes intense and severe pain in the postoperative period. Erector spinae plane (ESP) block can target the dorsal-ventral rami of thoracolumbar nerves, but its effect on lumbar surgery is unclear. The aim of this study was to investigate the effect of the ESP block on postoperative opioid consumption and pain scores in patients undergoing spinal surgery.

METHODS

Sixty patients undergoing open lumbar decompression surgery were randomly assigned to 2 groups. The ESP Group (n = 30) received ultrasound-guided bilateral ESP block with 0.25% bupivacaine 20 mL. In the Control Group (n = 30), no intervention was performed. Postoperative analgesia was performed intravenously twice a day with 400 mg ibuprofen and patient-controlled analgesia with tramadol. Postoperative visual analogue scale scores, opioid consumption, rescue analgesia, and opioid-related side effects were evaluated.

RESULTS

Compared with the Control Group, the visual analogue scale scores were statistically lower in the ESP Group during all measurements of time, both at rest and active movement (P < 0.05). Tramadol consumption was lower in the ESP Group compared with the Control Group at all time periods (P < 0.05). Twenty-four hour tramadol consumption in the Control Group was significantly higher compared with the ESP Group (370.33 ± 73.27 mg and 268.33 ± 71.44 mg; P < 0.001, respectively) and the difference was 28%, and time to first analgesic requirement was significantly longer in the ESP Group than in the Control Group.

CONCLUSIONS

ESP block can be used in multimodal analgesia practice to reduce opioid consumption and relieve acute postoperative pain in patients undergoing open lumbar decompression surgery.

Biomechanical effects of laminectomies in the human lumbar spine: a finite element study

BACKGROUND CONTEXT

Previous studies have analyzed the effect of laminectomy on intervertebral disc (IVD), facet-joint-forces (FJF), and range of motion (ROM), while only two have specifically reported stresses at the pars interarticularis (PI) with posterior element resection. These studies have been performed utilizing a single subject, questioning their applications to a broader population.

PURPOSE

We investigate the effect of graded PI resection in a three-dimensional manner on PI stress to provide surgical guidelines for avoidance of iatrogenic instability following lumbar laminectomy. Additionally, quantified FJF and IVD stresses can provide further insight into the development of adjacent segment disease.

STUDY DESIGN

Biomechanical finite element (FE) method investigation of the lumbar spine.

METHODS

FE models of the lumbar spine of three subjects were created using the open-source finite element software, FEBio. Single-level laminectomy, two-level laminectomy, and ventral-to-dorsal PI resection simulations were performed with varying degrees of PI resection from 0% to 75% of the native PI. These models were taken through cardinal ROM under standard loading conditions and PI stresses, FJF, IVD stresses, and ROM were analyzed.

RESULTS

The three types of laminectomy simulated in this study showed a nonlinear increase in PI stress with increased bone resection. Axial rotation generated the most stress at the PI followed by flexion, extension and lateral bending. At 75% bone resection all three types of laminectomy produced PI stresses that were near the ultimate strength of human cortical bone during axial rotation. FJF decreased with increased bone resection for the three laminectomies simulated. This was most notable in axial rotation followed by extension and lateral bending. IVD stresses varied greatly between the nonsurgical models and likewise the effect of laminectomy on IVD stresses varied between subjects. ROM was mostly unaffected by the laminectomies performed in this study.

CONCLUSIONS

Regarding the risk of iatrogenic spondylolisthesis, the combined results are sufficient evidence to suggest surgeons should be particularly cautious when PI resection exceeds 50% bone resection for all laminectomies included in this study. Lastly, the effects seen in FJF and IVD stresses indicate the degree to which the remainder of the spine must experience compensatory biomechanical changes as a result of the surgical intervention.

Full-endoscopic versus microscopic spinal decompression for lumbar spinal stenosis: a systematic review & meta-analysis

BACKGROUND CONTEXT

Symptomatic lumbar spinal stenosis is routinely treated with spinal decompression surgery, with an increasing trend towards minimally invasive techniques. Endoscopic decompression has emerged as a technique which minimizes approach-related morbidity while achieving similar clinical outcomes to conventional open or microscopic approaches.

PURPOSE

To assess the safety and efficacy of endoscopic versus microscopic decompression for treatment of lumbar spinal stenosis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review on randomized and nonrandomized studies comparing endoscopic versus microscopic decompression was conducted, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Treatment effects were computed using pairwise random-effects meta-analysis. Risk of bias was assessed using the Cochrane Risk-of-bias and ROBINS-I tools for randomized and nonrandomized trials respectively. Quality of the overall body of evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

A total of 19 primary references comprising 1,997 patients and 2,132 spinal levels were included. Endoscopic decompression was associated with significantly reduced intraoperative blood-loss (weighted mean differences [WMD]=-33.29 mL, 95% CI:-51.80 to -14.78, p=.0032), shorter duration of hospital stay (WMD=-1.79 days, 95% CI: -2.63 to 0.95, p=.001), rates of incidental durotomy (RR = 0.63, 95% CI: 0.43 to 0.91, p=.0184) and surgical site infections (RR=0.23, 95% CI: 0.10 to-0.51, p=.001), and a nonsignificant trend towards less back pain, leg pain, and better functional outcomes compared to its microscopic counterpart up to 2-year follow up.

CONCLUSIONS

Endoscopic and microscopic decompression are safe and effective techniques for treatment of symptomatic lumbar spinal stenosis. Prospective studies of larger power considering medium to long-term outcomes and rates of iatrogenic instability are warranted to compare potential alignment changes and destabilization from either techniques.

Functional Connectivity Analysis and Prediction of Pain Relief in Association with Spinal Decompression Surgery

BACKGROUND

Although spinal decompression surgery is an effective treatment for myelopathy-induced upper limb pain, some postoperative patients suffer from residual pain in spite of adequate decompression. However, the neural mechanism underlying the poor outcome of pain relief is still unclear. The goal of this study was to explore the brain mechanisms involved in the poor recovery of upper limb pain after the spinal decompression surgery by using functional connectivity (FC) analysis.

METHODS

In this cross-sectional study, 17 patients who underwent cervical spinal decompression surgery were included. Functional MRI (fMRI) during a tactile stimulus for each hand was performed at 1 day before and 7 days after the surgery. In total, 34 fMRI scans (17 left and right upper limbs, respectively) were obtained before and after the surgery, respectively. The patients were divided into poor-recovery and good-recovery groups, and then we searched for the FC that was related to poor-recovery.

RESULTS

The poor-recovery group (n = 15) showed significantly stronger connectivity between the postcentral gyrus (postCG) and dorsolateral prefrontal cortex (DLPFC) than the good-recovery group (n = 12) preoperatively. When the cutoff value of the preoperative FC between the left postCG and right middle frontal gyrus included in DLPFC was >0.17, the sensitivity and specificity for poor recovery were 73% and 75%, respectively.

CONCLUSIONS

Our study showed that FC between the postCG and DLPFC may be a predictor of pain relief. This result suggested that assessing FC can lead to more informed surgical interventions for cervical spondylotic myelopathy.

A quantitative review of finite element-based biomechanics of lumbar decompression surgery

Lumbar decompression surgeries are commonly performed in the USA to treat pain from spinal stenosis, often with little to no biomechanical evidence to evaluate the risks and benefits of a given surgery. Finite element models of lumbar spinal decompression surgeries attempt to elucidate the biomechanical benefits and risks of these procedures. Each published finite element model uses a unique subset of lumbar decompression surgeries, a unique human lumbar spine, and unique model inputs. Thus, drawing conclusions about biomechanical changes and biomechanical complications due to surgical variations is difficult. This quantitative review performed an analysis on the stresses, forces, and range of motion reported in lumbar spine finite element models that focus on spinal decompression surgeries. To accomplish this analysis, data from finite elements models of lumbar decompression surgeries published between 2000 and December 2023 were normalized to the intact spine and compared. This analysis indicated that increased bony resection and increased ligament resection are associated with increased pathologic range of motion compared to limited resection techniques. Further, a few individual studies show an increase in important outcomes such IVD stresses, pars interarticularis stresses, and facet joint forces due to decompression surgery, but the small number of published models with these results limits the generalizability of these findings to the general population. Future FE models should report these spinal stresses and incorporate patient-specific anatomical features such as IVD health, facet geometry, stenosis patient vertebrae, and vertebral porosity into the model.