The paravertebral lamina technique: a new regional anesthesia approach for breast surgery

The effect of preemptive retrolaminar block on lumbar spinal decompression surgery

PURPOSE

Spinal decompression surgery causes severe pain. Retrolaminar block (RLB) is block, which is done by infiltration of local anesthetic to block spinal nerves between the lamina and superior costotransversospinalis muscle. The primary aim of this study is to evaluate the effectiveness of RLB on postoperative analgesia in patients undergoing spinal surgery. Secondary aims are effects on additional anesthetic and analgesic consumption.

METHODS

The sixty (60) patients who underwent lumbar spinal surgery between May 2020 and May 2021 under general anesthesia with or without applied preemptive RLB for postoperative analgesia were included in this prospective observational study. Group I received ultrasound-guided preemptive RLB. In Group II, no intervention was performed. Postoperative VAS scores were compared in groups as primary outcome, perioperative additional anesthetic and analgesic needs were compared as secondary outcome.

RESULTS

There was a significant difference between the groups in favor of the RLB group in terms of postoperative VAS scores at rest [1.33 (0.33-3.509)] and movement [2.40 (1.20-4.00)] (p < 0.001). Perioperative sevoflurane consumption was significantly low in block group (p < 0.001). Postoperative tramadol consumption was lower in Group I compared with Group II [Group 1: 200 (100-300); Group 2: 37.5 (0-200); p < 0.001].

CONCLUSION

Preemptive RLB may be used to reduce patients' pain in lumbar decompression surgery as well as to be part of a multimodal analgesia and anesthesia regimen to reduce anesthetic and analgesic drug consumption. Trial registration numberClinicalTrials.gov (No. NCT04209907).

Local anesthetic dosing and toxicity of adult truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Anesthesiologists frequently use truncal catheters for postoperative pain control but with limited characterization of dosing and toxicity.

OBJECTIVE

We reviewed the published literature to characterize local anesthetic dosing and toxicity of paravertebral and transversus abdominis plane catheters in adults.

EVIDENCE REVIEW

We searched the literature for bupivacaine or ropivacaine infusions in the paravertebral or transversus abdominis space in humans dosed for 24 hours. We evaluated bolus dosing, infusion dosing and cumulative 24-hour dosing in adults. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 121 and 108 papers for ropivacaine and bupivacaine respectively with a total of 6802 patients. For ropivacaine and bupivacaine, respectively, bolus dose was 1.4 mg/kg (95% CI 0.4 to 3.0, n=2978) and 1.0 mg/kg (95% CI 0.18 to 2.1, n=2724); infusion dose was 0.26 mg/kg/hour (95% CI 0.06 to 0.63, n=3579) and 0.2 mg/kg/hour (95% CI 0.06 to 0.5, n=3199); 24-hour dose was 7.75 mg/kg (95% CI 2.1 to 15.7, n=3579) and 6.0 mg/kg (95% CI 2.1 to 13.6, n=3223). Twenty-four hour doses exceeded the package insert recommended upper limit in 28% (range: 17%-40% based on maximum and minimum patient weights) of ropivacaine infusions and 51% (range: 45%-71%) of bupivacaine infusions. Toxicity occurred in 30 patients and was associated with high 24-hour dose, bilateral catheters, cardiac surgery, cytochrome P-450 inhibitors and hypoalbuminemia.

CONCLUSION

Practitioners frequently administer ropivacaine and bupivacaine above the package insert limits, at doses associated with toxicity. Patient safety would benefit from more specific recommendations to limit excessive dose and risk of toxicity.

The postoperative analgesia of retrolaminar block in patients undergoing surgery with general anesthesia: a systematic review

INTRODUCTION

Postoperative pain has always been a difficult problem in anesthesia management. The neurological block technique has been used for postoperative analgesia management, but compared with the traditional block method, the effect of postoperative analgesia after layer block is still controversial, and a clear literature review is needed. This systematic review's goal was to investigate RLB's impact on postoperative analgesia.

EVIDENCE ACQUISITION

The literature search was performed using the PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Patients aged 18 years who underwent retrolaminar block were considered eligible. The article must report the results of the original study related to postoperative analgesia. The characteristics of the study sample and evaluating the RLB for postoperative analgesia were extracted from each included article and concluded.

EVIDENCE SYNTHESIS

Eleven randomized controlled trials (726 patients) were included. After summarizing the analysis of the results of RLB on changing postoperative analgesia indexes in different surgeries, we concluded that PVB is better used for postoperative analgesia compared with RLB. The analgesic effect of RLB provides advantages compared with EPSB, SCPB, etc.

CONCLUSIONS

Based on the results of this review, RLB can be applied to thoracic surgery, abdominal surgery and parotid surgery, but its analgesic effect is not significant enough, and further research is needed in the future to provide stronger evidence for postoperative analgesia in surgical patients.

Comparison of Ultrasound-Guided Versus Anatomical Landmark-Guided Thoracolumbar Retrolaminar Techniques in Canine Cadavers

The retrolaminar block was developed in humans as an easier and safer alternative to the thoracic paravertebral block. This study aims to describe an ultrasound-guided thoracolumbar retrolaminar injection in canine cadavers and compare the injectate distribution between a landmark-guided and an ultrasound-guided thoracolumbar retrolaminar technique using computed tomography. Ten canine cadavers were randomised to receive two injections each of 0.6 mL/kg of iodinated contrast at the level of the twelfth thoracic vertebra (T12): a landmark-guided retrolaminar injection was performed on one hemithorax (group B, n = 10) and an ultrasound-guided on the other hemithorax (group U, n = 10). Groups were compared using the Mann-Whitney U test. The median (range) spread of the contrast in the paravertebral space was 0 (0-3) and 1 (0-5) vertebrae in groups B and U, respectively (p = 0.038). The median (range) extent of the spread surrounding the interverbal foramina was 4 (0-5) in group B and 4 (3-5) in group U. The median (range) spread along the retrolaminar space cranial and caudal to T12 was 3 (0-6) retrolaminar segments in group B and 3 (3-4) in group U. The potential of the ultrasound-guided retrolaminar injection to provide analgesia for dogs suffering from thoracolumbar pain should be further investigated.

Thoracolumbar Retrolaminar Block: Anatomical and Radiological Study of Injectate Pattern Distribution in Canine Cadavers

The retrolaminar block is a regional anaesthetic technique, first developed in humans, in which the local anaesthetic is deposited directly onto the dorsal aspect of the thoracic or lumbar vertebral lamina. This study aims to evaluate the distribution of landmark-guided thoracolumbar retrolaminar injections in greyhound cadavers. Thirteen injections of contrast-dye solution were performed in eight cadavers at the level of the twelfth thoracic vertebra (T12), with either 20 mL (n = 8, high volume, HV) or 10 mL (n = 5, low volume, LV) per site. The spread of the injectate was evaluated through computed tomography and transverse anatomical dissection. The groups were compared using the Mann-Whitney U test. The median (range) of the extent of the spread was 4 (2-5) and 3 (2-4) intervertebral foramina in the LV and HV groups, respectively. The median (range) of the spread along the retrolaminar space was 3 (2-3) retrolaminar segments in the LV and 3 (2-4) in the HV group. Epidural and retroperitoneal spread was identified in seven cadavers. Following landmark-guided retrolaminar injections, the injectate spread both in the retrolaminar and paravertebral spaces, without any obvious association between the volume of injectate and the extent of the spread. Further studies are warranted to determine the clinical efficacy of the technique.

Comparison of Edge of Lamina Block with Thoracic Paravertebral Block and Retrolaminar Block for Analgesic Efficacy in Adult Patients Undergoing Video-Assisted Thoracic Surgery: A Prospective Randomized Study

Background

A novel ultrasound-guided paravertebral block, the edge laminar block (ELB) was reported recently. However, it was unclear how effective ELB was in comparison with traditional blocking methods. We conducted a trial to compare the analgesic efficacy of ELB with the thoracic paravertebral block (TPVB) and the retrolaminar block (RLB) in patients undergoing video-assisted thoracic surgery (VATS).

Methods

We identified 90 patients who were scheduled for VATS and randomly assigned them to three groups: ELB group (Group E), TPVB group (Group T), and RLB group (Group R). Each group underwent ELB, TPVB, and RLB, respectively, under ultrasound guidance before general anesthesia induction. All patients received post-operative routine analgesia protocol. Our primary outcome was the extent of dermatomal sensory loss on the midclavicular, midaxillary, and scapular lines, measured using a pinprick 15 minutes after the nerve block. Secondary outcomes included the intraoperative dose of sufentanil, the numerical rating scale (NRS) scores assessed in the post-anesthesia care unit (PACU) and at 6, 12, and 24 hours post-operatively, and pethidine administrated as analgesic rescue dose.

Results

The percentages of nerve block range reaching the midclavicular line, midaxillary line, and scapular line in Group E were 96.7%, 93.3%, 93.3%, and 60% in Group T and 30%, 56.7%, and 96.7% in Group R, respectively. Group E had wider dermatomal sensory loss on the midclavicular line and midaxillary line compared to Group R (P < 0.001) and had a wider range compared to Group T on the scapular line (P < 0.001). There was no significant difference in the intraoperative use of sufentanil in the three groups. Post-operative NRS scores at each time point were significantly lower in Group E than those in the other two groups (P < 0.01).

Conclusion

ELB had a wider nerve block range and applied better post-operative analgesia in comparison with TPVB and RLB.

Thoracolumbar retrolaminar block in seven dogs undergoing spinal surgery

Background

Thoracolumbar intervertebral disc extrusion is a common neurologic complaint in dogs and is associated with debilitating pain that requires careful analgesic management to avoid the transition to a chronic pain state. Recently, there has been an increased effort to incorporate regional anaesthetic techniques whenever possible, both for perioperative analgesia management and for prevention of chronic pain. A novel regional anaesthetic technique named retrolaminar block is a fascial plane block where the local anaesthetic is injected directly on top of the dorsal aspect of the vertebral lamina, in the fascial plane between the lamina and the epaxial muscles. The technique was recently described in humans and it is claimed to provide analgesia in patients undergoing thoracic and lumbar procedures. To the authors’ knowledge, the retrolaminar block has not been previously reported in live dogs.

Case presentation

Seven dogs presented to our hospital for suspected thoracolumbar intervertebral disc extrusion were anaesthetised using an anaesthetic premedication and induction protocol tailored for each individual animal. Once the suspected diagnosis was confirmed, all seven dogs were placed in sternal recumbency, and the target thoracolumbar vertebral spinous process was identified with palpation. A unilateral retrolaminar block was performed in all dogs with 2 mg/kg of 0.25% bupivacaine. Physiologic parameters, as well as responses to nociceptive stimuli, were monitored throughout the anaesthetic event.

Intraoperatively, one dog required a bolus of fentanyl to control nociceptive stimulation while the epaxial muscles were retracted. No further intraoperative rescue analgesia was required in any of the cases. The postoperative pain was assessed using the Short Form of Glasgow Composite Measure Pain Scale for dogs every four hours for the duration of the dogs’ hospitalization. The retrolaminar block reduced the intraoperative requirement for systemic opioids and other adjunct analgesic agents and all dogs were comfortable throughout their hospitalization and up until the time of their discharge.

Conclusions

This case report presents the performance of the retrolaminar block technique as part of multimodal analgesia management in seven dogs undergoing thoracolumbar spinal surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13620-022-00224-7.

Anatomical classification and clinical application of thoracic paraspinal blocks

Various techniques for regional anesthesia and analgesia of the thorax are currently being used in clinical practice. A recent international consensus has anatomically classified paraspinal blocks in the thoracic spinal region into the following four types: paravertebral, retrolaminar, erector spinae plane, and intertransverse process blocks. These blocks have different anatomical targets; thus, the spreading patterns of the injectates differ and can consequently exhibit different neural blockade characteristics. The paravertebral block directly targets the paravertebral space just outside the neuraxial region and has an analgesic efficacy comparable to that of the epidural block; however, there are multiple potential risks associated with this technique. Retrolaminar and erector spinae plane blocks target the erector spinae plane on the vertebral lamina and transverse process, respectively. In anatomical studies, these two blocks showed different injectate spreading patterns to the back muscles and the fascial plane. In cadaveric studies, paravertebral spread was identified, but variable. However, numerous clinical reports have shown paravertebral spread with erector spinae plane blocks. Both techniques have been found to reduce postoperative pain compared to controls; however, the results have been more inconsistent than with the paravertebral block. Finally, the intertransverse process block targets the tissue complex posterior to the superior costotransverse ligament. Anatomical studies have revealed that this block has pathways that are more direct and closer to the paravertebral space than the retrolaminar and erector spinae plane blocks. Cadaveric evaluations have consistently shown promising results; however, further clinical studies using this technique are needed to confirm these anatomical findings.

The effect of ultrasound-guided bilateral thoracic retrolaminar block on analgesia after pediatric open cardiac surgery: a randomized controlled double-blind study

Background

The thoracic retrolaminar block (TRLB) is a relatively new regional analgesia technique that can be used as an alternative to the thoracic paravertebral block. This study aimed to evaluate the postoperative analgesia effects of ultrasound-guided TRLB in children undergoing open cardiac surgery via median sternotomy incision.

Methods

Sixty-six patients aged 2–8 years were recruited. In the TRLB group, 0.25% bupivacaine 0.4 ml/kg was injected into the retrolaminar space on both sides at the level of the T4 lamina. Patients in the control group were injected with 0.9% saline. The primary outcome measure was fentanyl consumption in the first 24 h post-extubation. The secondary outcome measures were the total intraoperative fentanyl consumption, postoperative modified objective pain score (MOPS), and time to extubation.

Results

The total intraoperative fentanyl requirements and fentanyl consumption in the first 24 h post-extubation were significantly lower (P < 0.001) in the TRLB group (9.3 ± 1.2; 6.9 ± 2.1 μg/kg, respectively) than in the control group (12.5 ± 1.4; 16.6 ± 2.8, respectively). The median (Q1, Q3) time to extubation was significantly shorter (P < 0.001) in the TRLB group (2 [1, 3] h) than in the control group (6 [4.5, 6] h). The MOPS was significantly lower (P < 0.05) in the TRLB group than in the control group at 0, 2, 4, 8, 12 and 16 h post-extubation.

Conclusions

Bilateral ultrasound-guided TRLB is effective in providing postoperative analgesia in children undergoing open cardiac surgery via median sternotomy incision.

Ultrasound-guided retrolaminar block versus ilioinguinal nerve block for postoperative analgesia in children undergoing inguinal herniotomy: A randomized controlled trial

STUDY OBJECTIVE

Ultrasound-guided retrolaminar block (RLB) is a new, safe and technically easy nerve block. To our knowledge, no studies have evaluated its analgesic efficacy in pediatric patients. This study aimed to compare the postoperative analgesic efficacy of RLB and ilioinguinal nerve block (INB) in pediatric patients undergoing unilateral inguinal herniotomy.

DESIGN

Superiority, prospective, randomized, double-blinded, controlled study.

SETTING

Operating rooms and wards of Mansoura University Children's Hospital, Egypt.

PATIENTS

Sixty-five patients aged 2 to 6 years undergoing unilateral inguinal herniotomy were enrolled.

INTERVENTIONS

In the ultrasound-guided RLB group (n = 30), we injected 0.5 mL/kg bupivacaine 0.25% into the retrolaminar space between the lamina of T12 and the paraspinal muscles and in ultrasound-guided INB group (n = 30), 0.5 mL/kg bupivacaine 0.25% was injected for INB.

MEASUREMENTS

The primary outcome measure was the number of patients requiring ibuprofen as rescue analgesia and the secondary outcome measures were intraoperative hemodynamic changes and the postoperative FLACC (Face, Legs, Activity, Cry, Consolability) score.

MAIN RESULTS

The number of patients who needed rescue analgesia in the first postoperative 24 h was significantly lower (P = 0.023) in the RLB group [5 (16%)] than the INB group [13 (43%)]. The mean (SD) arterial blood pressure and heart rate were significantly higher (P < 0.001) during sac traction in the INB group [74.07 (2.99), 97.33 (6.98)] than the RLB group [67.73 (3.55), 90.79 (5.13)]. The postoperative FLACC scores at 4, 6, 12, and 24 h were significantly lower (P < 0.05) in the RLB group than in the INB group.

CONCLUSION

Retrolaminar block is superior to ilioinguinal nerve block in providing postoperative analgesia in pediatric patients undergoing unilateral inguinal herniotomy.

High-volume, multilevel local anesthetics-Epinephrine infiltration in kyphoscoliosis surgery: Intra and postoperative analgesia

Background and Aims:

Local anesthetic (LA) infiltration is one of the analgesic techniques employed during scoliosis correction surgery. However, its efficacy is controversial. In the present study for optimizing analgesia using the infiltration technique, we proposed two modifications; first is the preemptive use of high volume infiltration, second is applying three anatomical multilevel infiltrations involving the sensory, motor, and sympathetic innervations consecutively.

Material and Methods:

This prospective study involved 48 patients randomized into two groups. After general anesthesia (GA), the infiltration group (I) received bupivacaine 0.5% 2 mg/kg, lidocaine 5 mg/kg, and epinephrine 5 mcg/mL of the total volume (100 mL per 10 cm of the wound length) as a preemptive infiltration at three levels; subcutaneous, intramuscular, and the deep neural paravertebral levels, timed before skin incision, muscular dissection, and instrumentation consecutively. The control group (C) received normal saline in the same manner. Data were compared by Mann-Whitney, Chi-square, and t-test as suitable.

Results:

Intraoperatively, the LA infiltration reduced fentanyl, atracurium, isoflurane, nitroglycerine, and propofol consumption. Postoperatively, there was a 41% reduction in morphine consumption, longer time to the first analgesic request, lower VAS, early ambulation, and hospital discharge with high-patient satisfaction.

Conclusion:

The preemptive, high-volume, multilevel infiltration provided a significant intra and postoperative analgesia in scoliosis surgery.

Retrolaminar Block Versus Paravertebral Block for Pain Relief After Less-Invasive Lung Surgery: A Randomized, Non-Inferiority Controlled Trial

Introduction

A retrolaminar block (RLB) is a modified paravertebral technique with a local anesthetic injected at the retrolaminar site. The aim of this non-inferiority, parallel-group, prospective, and randomized study was to compare the analgesic efficacy of the paravertebral block (PVB) and RLB after lung surgery.

Methods

Eligible subjects were patients aged more than 20 years, with American Society of Anesthesiologists physical status Ⅰ or II, who were scheduled to undergo video-assisted thoracoscopic surgery (VATS) or limited thoracotomy because of lung disease. Patients were randomly allocated to receive either a PVB or RLB using a computer-generated sequence and sealed opaque envelopes. The PVB and RLB were induced by injecting 20 mL of 0.50% ropivacaine and 40 mL 0.25% ropivacaine, respectively. As the primary outcome variable, we considered the area under the curve (AUC) of the postoperative pain intensity using the trapezoidal method. Pain intensity was assessed using an 11-point numerical rating scale (NRS). We converted the NRS (0-10) into the visual analog scale (VAS) (0-100 mm) proportionally. We compared the AUC of the converted NRS (AUC-cNRS) on coughing between one and two hours after the operation. The non-inferiority margin was set at 25 mm × h in the AUC-cNRS. Patients and nurses were blinded to group assignments. Secondary outcomes included time to perform the block, NRS for pain intensity at rest and on coughing at one, two, four, 24, and 48 hours after the operation, the incidence of postoperative nausea and vomiting, time to first morphine use after the operation, and cumulative morphine consumption at 24 and 48 hours after the operation.

Results

In each group, 25 patients were randomized and analyzed. No significant difference in the AUC-cNRS was noted between the groups (P = 0.117). The mean difference in the AUC-cNRS (group RLB minus group PVB) was 13.42 mm × h, 95% confidence interval, −3.48 to 30.32 mm × h. However, when patients with unexpectedly extended skin incision were excluded from the analysis, the AUC-cNRS of group RLB was significantly higher as compared to group PVB (P = 0.0388). The time to perform the block was longer in PVB as compared to the RLB group (P < 0.0001). No significant differences were noted in the remaining secondary outcomes.

Conclusion

The non-inferiority of RLB as compared to PVB was not confirmed. Though RLB has the advantage of a shorter time to perform, RLB is not recommended for patients undergoing VATS or limited thoracotomy because of lack of efficacy as compared to PVB.

Ultrasound-guided fascial plane blocks of the chest wall: a state-of-the-art review

Ultrasound-guided fascial plane blocks of the chest wall are increasingly popular alternatives to established techniques such as thoracic epidural or paravertebral blockade, as they are simple to perform and have an appealing safety profile. Many different techniques have been described, which can be broadly categorised into anteromedial, anterolateral and posterior chest wall blocks. Understanding the relevant clinical anatomy is critical not only for block performance, but also to match block techniques appropriately with surgical procedures. The sensory innervation of tissues deep to the skin (e.g. muscles, ligaments and bone) can be overlooked, but is often a significant source of pain. The primary mechanism of action for these blocks is a conduction blockade of sensory afferents travelling in the targeted fascial planes, as well as of peripheral nociceptors in the surrounding tissues. A systemic action of absorbed local anaesthetic is plausible but unlikely to be a major contributor. The current evidence for their clinical applications indicates that certain chest wall techniques provide significant benefit in breast and thoracic surgery, similar to that provided by thoracic paravertebral blockade. Their role in trauma and cardiac surgery is evolving and holds great potential. Further avenues of research into these versatile techniques include: optimal local anaesthetic dosing strategies; high-quality randomised controlled trials focusing on patient-centred outcomes beyond acute pain; and comparative studies to determine which of the myriad blocks currently on offer should be core competencies in anaesthetic practice.

Paravertebral Block for a Patient With Achalasia Undergoing a Peroral Endoscopic Myotomy Procedure: A Case Report

In 2016, the American Medical Association officially dismissed pain as a vital sign quoting the opioid epidemic as a major reason. Clinically, pain remains very relevant and we present the case of a patient with achalasia treated via peroral endoscopic myotomy procedure (POEM). Given that similar patients previously failed traditional pain management modalities, regional anesthesia was used in this patient's pain management. The positive outcomes yielded from this technique convinced our gastroenterological colleagues to request regional anesthesia for future patients, altering their approach to pain management.

Are single-injection erector spinae plane block and multiple-injection costotransverse block equivalent to thoracic paravertebral block?

BACKGROUND

Thoracic paravertebral block (TPVB) is considered the gold standard for hemithoracic regional anaesthesia. Erector spinae plane block (ESPB) is a new posterior thoracic wall block. Multiple-injection costotransverse block (MICB) mimics TPVB but with injection points within the thoracic intertransverse tissue complex and posterior to the superior costotransverse ligament. We aimed to compare the spread of injectate into the thoracic paravertebral space (TPVS) resulting from single-injection ESPB and MICB, respectively, with TPVB.

METHODS

Ten soft-embalmed cadavers were utilised. In five cadavers, the right hemithorax was randomly allocated either to ultrasound-guided single-injection ESPB or single-injection TPVB; vice versa on the other side. In another five cadavers, the right hemithorax was randomly allocated either to ultrasound-guided MICB or multiple-injection TPVB. About 20 mL of dye was injected in each hemithorax with all techniques.

RESULTS

With TPVB, the dye was consistently present in the TPVS with concomitant epidural spread in the majority of cases. The injectate spread into the TPVS with ESPB (60%) and MICB (100%). MICB consistently stained the ventral rami (T1-7), communicating rami and thoracic sympathetic trunk without epidural spread. Dissection after MICB revealed dye spread into the TPVS via the costotransverse foramina and along the dorsal branches of the posterior intercostal veins.

CONCLUSIONS

Consistent spread of dye into the TPVS colouring the ventral rami, the communicating rami, and the sympathetic trunk was observed with MICB; in this respect equivalent to TPVB. ESPB exhibited only partial success and was not equivalent to TPVB. No epidural spread was found with neither MICB nor ESPB.

Interfascial plane blocks

Many novel interfascial plane blocks have been developed in the last 10 years in the effort to improve perioperative pain management that are safe, efficacious, efficient, and inexpensive. These blocks have been widely adopted into clinical practice despite relatively few high-quality clinical investigations of the techniques and how they affect perioperative outcomes. This article defines interfascial plane blocks, discusses the potential benefits, reviews the most common techniques and evidence supporting their indication, and guides clinicians in selecting an appropriate interfascial plane block for different types of surgical procedures.

[Efficacy of erector spinae block versus retrolaminar block for postoperative analgesia following posterior lumbar surgery]

OBJECTIVE

To compare the effect of erector spinae plane block and retrolaminar block for relieving acute pain after posterior lumbar surgery.

METHODS

Eighty-nine patients undergoing selective posterior lumbar surgery under general anesthesia in our hospital between January and December, 2018, were recruited. Of these patients, 30 received total intravenous general anesthesia to serve as the control group, 28 received total intravenous general anesthesia (TIVA) combined with erector spinae plane block (ESPB), and 31 had TIVA combined with retrolaminar block (RLB). All the patients received patient-controlled intravenous analgesia (PCIA) for postoperative analgesia, and their heart rate, blood pressure, and pulse oximetry were routinely monitored during the anesthesia. VAS scores were evaluated before and at 2, 8, 12, 24, and 48 h after the surgery. Sufentanil consumption during the operation and PCIA were also recorded. The postoperative complications such as nausea and vomiting, urinary retention, itching and respiratory depression within 48 h after the surgery were also recorded.

RESULTS

At 2, 8 and 12 h postoperatively, VAS scores in the ESPB group and RLB group were significantly lower than those in the control group; the scores were significantly lower in RLB group than in ESPB group (P &lt; 0.05). Compared with that in the control group, sufentanil consumption during the operation and PCIA were significantly decreased in both ESPB and RLB groups, particularly in the latter group (P &lt; 0.05). Two patients experienced nausea and vomiting and 1 patient complained of pruritus in control group; 1 patient had over sedation and 1 had urinary retention in ESPB group; 1 patient had urinary retention in RLB group.

CONCLUSIONS

Ultrasound-guided RLB has better analgesic effect than ESPB for management of perioperative pain following posterior lumbar surgery.

Comparison of Clinical Efficacy and Anatomical Investigation between Retrolaminar Block and Erector Spinae Plane Block

Retrolaminar block (RLB) and erector spinae plane block (ESPB) are alternative approaches to paravertebral block (PVB) and are advantageous in that they are easier and safer techniques compared with the traditional PVB. Many clinical reports of these blocks have described their efficacy for ipsilateral thoracic analgesia. The local anesthetic injection points of RLB and ESPB are the lamina and transverse process, respectively. Despite the similarity of the puncture sites, there have been no clinical studies comparing RLB and ESPB. In addition, the underlying mechanism of these blocks has not been clarified. Recent anatomical investigations indicated that the injectate was distributed in the paravertebral space and spread laterally into the intercostal spaces. The limited distribution into the paravertebral space indicated that compared to PVB, RLB and ESPB exert their effects via a different mechanism. In this review, we describe the features of and differences between RLB and ESPB based on current clinical and anatomical reports. We also propose the clinical indication and discuss the differences, clinical outcomes, and anatomical mechanisms of the techniques.

Inadvertent Spinal Anesthesia During Ultrasound-Guided Thoracic Paravertebral Nerve Block in a Patient With Nerve Root Sheath Cyst: A Case Report

An ultrasound-guided thoracic paravertebral nerve block was administered for left-sided abdominal pain. Lidocaine 0.4% (9.5 mL) was injected. Spinal anesthesia developed after the injection that resolved after 3 hours. One week later, a magnetic resonance imaging scan of thoracic spine identified a left T10 nerve root sheath cyst. It was postulated that the local anesthetic was injected into the cyst, which communicated with the subarachnoid space. This case report demonstrates the anatomic variations of nerve root sheath cyst sites and the risk of injection into intranerve root sheath cysts during interventional procedures.

Is a Retrolaminar Approach to the Thoracic Paravertebral Space Possible?: A Human Cadaveric Study

BACKGROUND AND OBJECTIVES

The retrolaminar block (RB) is used for truncal analgesia, but its mechanism of neural blockade remains obscure. We sought to learn the pattern of local anesthetic spread after thoracic RB using cadaveric models.

METHODS

In 8 fresh cadavers, an ultrasound-guided T4 RB was performed with 20 mL of methylene blue 1% and bupivacaine 0.5%. For comparison, an RB at T9 in 1 cadaver and a T4 thoracic paravertebral block in another cadaver were performed. Subsequently, posterior and anterior thoracic dissections were performed to examination where the dye spread.

RESULTS

After T4 RB, dye was noted to spread in the ipsilateral retrolaminar plane (all 8 cadavers, median cephalad spread 3.5 cm, caudad spread 10.7 cm, lateral spread 2.5 cm), the contralateral retrolaminar plane (6 cadavers), the paravertebral space (5 cadavers, median of 3 segments, T3-T5), the intercostal space (5 cadavers, median of 3.5 cm laterally), the T4 epidural space (6 cadavers), and the intervertebral foramina (4 cadavers, median of 2 segments, T4-T5). After T9 retrolaminar injection, dye was noted in the ipsilateral retrolaminar plane (5.5 cm cephalad, 13.5 cm caudad, and 2.5 cm lateral), the contralateral retrolaminar plane, and the epidural space. Dye after T4 traditional paravertebral block spread to T1-T6 paravertebral space with 15-cm lateral spread.

CONCLUSIONS

Injectate spread to the paravertebral space, epidural space, intercostal space, and intervertebral foramina is possible in the RB but is quite variable. In comparison to the thoracic paravertebral block, injectate spread within the paravertebral space is more limited.

The ultrasound-guided retrolaminar block: volume-dependent injectate distribution

Purpose

The ultrasound-guided retrolaminar block is one of the newer and simpler alternatives to the traditional, often technically challenging, paravertebral (PV) block. Its feasibility, safety, and efficacy have already been clinically demonstrated in patients with multiple rib fractures using higher volumes of local anesthetic, when compared with the traditional approach. The primary aim of this observational anatomical study was to assess the spread of local anesthetic from the retrolaminar injection point to the PV space and its volume dependence. Second, we assessed the incidence of epidural and contralateral PV spread in the both groups.

Methods

Ten fresh porcine cadavers were randomized into 2 groups (n=5 each) to receive ultrasound-guided retrolaminar injections at Th4-Th5 level with either 10 mL (low-volume group) or 30 mL (high-volume group) of 2% lidocaine and methylene blue mixture. After the procedure, the cadavers were dissected and frozen. Cross-section cuts (~1 cm thick) were performed to evaluate the injectate spread.

Results

In the high-volume group, injectate spread from the retrolaminar to the PV space was observed in all specimens (5 out of 5; 100%), while in the low-volume group, no apparent spread to the PV space was found (0 out of 5; 0%). No epidural or contralateral PV spread was observed in any of the specimens.

Conclusion

Following ultrasound-guided retrolaminar injections in fresh porcine cadavers, injectate spread from the retrolaminar tissue plane to the PV space is strongly volume dependent, suggesting that, clinically, high local anesthetic volumes maybe critical for achieving regional anesthesia and analgesia consistent with traditional PV blockade.

Single-shot lamina thoracic paravertebral block with ketofol for modified radical mastectomy

We describe the use of single-shot lamina thoracic paravertebral block (TPVB) with sedation for a 56-year-old female patient who had modified radical mastectomy with axillary clearance. Two years ago, she suffered vocal cord palsy post thyroidectomy, which was managed with tracheostomy. The tracheostomy tube was removed 8 months later, leaving the patient with persistent hoarseness of voice and left vocal cord palsy. She declined general anesthesia and consented for TPVB. The surgery lasted 95 minutes and was successfully completed with TPVB. Her vital signs were stable during the operation. She had low pain scores, minimal opioid use, early alimentation, and no postoperative nausea and vomiting and was discharged early. We present the anesthetic management of this case in our setting, where TPVB under ultrasound guidance and modern drug-delivery systems for sedation are unavailable.

Retrolaminar block: analgesic efficacy and safety evaluation

PURPOSE

Retrolaminar block (RLB) is a thoracic truncal block that can produce analgesia for the thoracic and abdominal wall. However, the characteristics of RLB are not well known. The aim of this study was to determine analgesic efficacy by measuring postoperative consume of patient-controlled analgesia (PCA), additional nonsteroidal antiinflammatory drug (NSAID) rescue, and opioid rescue. Our secondary analysis included assessment of the chronological change in arterial levobupivacaine concentrations after the block.

METHODS

This prospective, randomized, double-blinded study included 30 patients scheduled for modified radical mastectomy under general anesthesia. The patients were randomized to receive either a landmark-guided RLB or paravertebral block (PVB) catheter placement on T4. Continuous infusion with 4 ml/h of 0.25 % levobupivacaine was started for 72 h, after initial injection of 20 ml 0.375 % levobupivacaine before surgery. Postoperative pain was compared using the amount of block PCA (3 ml 0.25 % levobupivacaine with 30-min lockout), NSAID, and opioid rescue. Arterial blood was sampled for 120 min after the initial injection.

RESULTS

The frequency of postoperative block PCA use was significantly high after RLB in 24 h [p = 0.01; 6 (3-12) vs. 2.5 (0.3-3) times, respectively]. There was no PCA use after 24 h in either group. There was no postoperative opioid rescue use throughout the study. After RLB and PVB, there was no significant difference in T _max (p = 0.14; 15 ± 8 vs. 15 ± 8 min, respectively) and C _max (p = 0.2; 0.9 ± 0.2 vs. 0.9 ± 0.3 µg/ml, respectively), and all the concentrations were below the threshold of local anesthetic systemic toxicity.

CONCLUSION

Continuous RLB was not inferior to PVB except for the first 24 h, and was satisfactory after mastectomy. RLB showed safe, low peak arterial levobupivacaine concentrations.