• Anatomy and Cell Biology
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• v.57 no.2
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• pp.229-237
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• 2024

The infiltration of the interspace between the popliteal artery and the capsule of the posterior knee (IPACK) block, is a novel ultrasound-guided technique used for postoperative pain management of the knee. The success of the block is attributed to the spread of injectate between the capsule of the knee and the popliteal artery. This novel technique is believed to target the articular branches of the tibial, common fibular (peroneal) and obturator nerves. However, the extent of the spread in a paediatric population is unknown. Therefore, this study aims to evaluate the spread of the IPACK block. Using ultrasound guidance, the IPACK block was replicated bilaterally in neonatal cadavers. Methylene blue dye (0.3 ml/kg) was injected proximally and distally. Subsequently, cadavers were dissected to determine the injectate spread. Proximal injections resulted in staining of some of the articular branches, while the distal injections resulted in staining of all four articular branches. Additional staining of the superior lateral and medial genicular nerves was noted irrespective of the technique. Overall, both injections resulted in posterior, anterolateral spread with limited medial spread. Results from this study reveal preservation of the main nerve trunks following the proximal technique, while the distal technique displayed greater staining of the articular branches. We believe that the block can be seen as a more holistic and viable alternative to lower limb blocks for the paediatric population, as it allows for a wider spread in the posterior and medial-lateral compartments of the knee.

• The Korean Journal of Pain
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• v.26 no.4
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• pp.396-400
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• 2013

Conventional transcrural CPB via the "walking off" the vertebra technique may injure vital organs while attempting to proximally spread injectate around the celiac plexus. Therefore, we attempted the CT-simulated fluoroscopy-guided transdiscal approach to carry out transcrural CPB in a safer manner, spreading the injectate more completely and closely within the celiac plexus area. A 54-year-old male patient with pancreatic cancer suffered from severe epigastric pain. The conventional transcrural approach was simulated, but the needle pathway was impeded by the kidney on the right side and by the aorta on the left side. After simulating the transdiscal pathway through the T11-12 intervertebral disc, we predetermined the optimal insertion point (3.6 cm from the midline), insertion angle (18 degrees), and advancement plane, as well as the proper depth. With the transdiscal approach, we successfully performed transcrural CPB within a narrow angle, and the bilateral approach was not necessary as we were able to achieve the bilateral spread of the injectate with the single approach.

• Clinical Pain
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• v.18 no.2
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• pp.59-64
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• 2019

Objective: This study evaluated the feasibility of ultrasound-guided lumbar nerve root block (LNRB) and S1 nerve root block by identifying spread patterns via fluoroscopy in cadavers. Method: A total of 48 ultrasound-guided injections were performed in 4 fresh cadavers from L1 to S1 roots. The target point of LNRB was the midpoint between the lower border of the transverse process and the facet joint at each level. The target point of S1 nerve root block was the S1 foramen, which can be visualized between the median sacral crest and the posterior superior iliac spine, below the L5-S1 facet joint. The injection was performed via an in-plane approach under real-time axial view ultrasound guidance. Fluoroscopic validation was performed after the injection of 2 cc of contrast agent. Results: The needle placements were correct in all injections. Fluoroscopy confirmed an intra-foraminal contrast spreading pattern following 41 of the 48 injections (85.4%). The other 7 injections (14.6%) yielded typical neurograms, but also resulted in extra-foraminal patterns that occurred evenly in each nerve root, including S1. Conclusion: Ultrasound-guided injection may be an option for the delivery of injectate into the S1 nerve root, as well as lumbar nerve root area.