Ultrasound-guided edge of laminar block is an alternative to paravertebral block

Thoracic paravertebral block (TPVB) has been used to provide good analgesia during percutaneous nephrolithotomy (PCNL) surgery.[1] However, TPVB is associated with a risk of significant consequences, including pneumothorax, intercostal vascular, and nerve injury. Newer methods, such as retrolaminar block (RLB) and erector spinae plane block (ESPB), are regarded as equally safe and could provide an alternative to TPVB. The aforementioned blocks are interfacial plane blocks that are performed without penetrating the superior costotransverse ligament or entering the paravertebral region. However, the results of these regional blocks are not extensively documented.[2] Shu et al.[3] reported a novel technique of RLB called the edge of laminar block (ELB) to provide sensory analgesia during rib fracture surgery. In this technique, they have injected local anesthetics at the lateral edge of the lamina. Here we are going to report a case series of ten patients scheduled for PCNL surgery in which ELB was given after general anesthesia. Written and informed consent was obtained for publication from all patients. All patients aged 20–70 years with a body mass index (BMI) <35 and ASA I and II received ELB. Block technique: a linear ultrasound probe (M-Turbo, Fujifilm Sonosite, Inc., Bothell, WA, USA) was placed in a transverse position at the spinous process of the T8–T9 vertebra. The probe was moved laterally to identify the vertebral lamina (VL), transverse process (TP), and rib [Figure 1]. A puncture needle was advanced by in-plane approach until the needle tip touched the lateral edge of "lamina's cliff" with some resistance [Figure 1]. A 20-ml volume of 0.25% bupivacaine was injected at the lateral edge of lamina's cliff after negative aspiration for blood and air.[3] In the intraoperative period, the opioid requirement was very low, and all vitals were within the normal limit. Postoperative multimodal analgesia consisted of intravenous paracetamol (10 mg/kg) every six hours. The postoperative pain score was measured using the numerical rating scale (NRS) for all patients at various time intervals.Figure 1: Panel - a: Needle probe position, Panel - b: Sonoanatomy edge of the laminar blockWe detected good analgesia (NRS <4) in the postoperative period most of the time. We have not detected any block-related complications in both the intraoperative and postoperative periods, and all patients were discharged without the need for analgesics. ELB worked wonderfully and kept the patient comfortable during the operation, lasting more than an hour without pain. Gao et al.[4] compared the ELB to thoracic paravertebral and RLB in VATS surgery and concluded that ELB was effective in blocking the anterior and posterior branches of the thoracic nerve simultaneously, had a wider nerve block range, and provided better post-operative analgesia than TPVB and RLB. Drug diffusion to the paravertebral space is not very clear, but some literature states that the posterior wall of the paravertebral space is slit-like and not completely closed by the superior costotransverse ligament.[5] Therefore, the LA diffuses into paravertebral space. We can say that the paravertebral migration of local anesthetics is greater in the ELB in comparison to the classical RLB. The ELB is an alternative to the paravertebral because drugs injected at the tip migrate directly to the paravertebral region. It is safer than paravertebral block because the needle tip comes into contact with the bony edge of the lamina, thus preventing complications like pneumothorax, spinal, or epidural injections of drugs. However, it remained uncertain whether ELB was more effective than typical blocking approaches. We hypothesized that ELB could be a promising regional block alternative to TPVB, but its efficacy and safety will have to be established in additional cases. We intend to carry out a larger clinical investigation in the near future. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.