BackgroundThe aim of this article was to provide a detailed description of the neonatal anatomy related to the erector spinae plane block and to report the spread of the dye within the fascial planes and potential dermatomal coverage.MethodsUsing ultrasound guidance, the bony landmarks and anatomy of the erector spinae fascial plane space were identified. The erector spinae plane block was then replicated unilaterally in two fresh unembalmed neonatal cadavers. Using methylene blue dye, the block was performed at vertebral levels T5—using 0.5 mL in cadaver 1—and T8—using 0.2 mL in cadaver 2. The craniocaudal spread of dye was tracked within the space on the ultrasound screen and further confirmed on dissection.ResultsCraniocaudal spread was noted from vertebral levels T3 to T6 when the dye was introduced at vertebral level T5 and from vertebral levels T7 to T11 when the dye was introduced at vertebral level T8. Furthermore, the methylene blue spread was found anteriorly in the paravertebral and epidural spaces, staining both the dorsal and ventral rami of the spinal nerves T2 to T12. Small amounts of dye were also found in the intercostal spaces.ConclusionIn two neonatal fresh cadavers, the dye was found to spread to multiple levels and key anatomic locations.

The extradural supraodontoid space lies anteriorly at the craniocervical junction (CCJ) between the alar ligaments and foramen magnum. It occupies the space between the tectorial and atlanto-occipital membranes. A variety of benign and traumatic lesions may result in neurological compression here with harmful effects. Decompression by the transoral surgical approach often provides relief from these effects. Knowledge of the detailed microanatomy of this space is fragmentary. The purpose of this study was to identify the boundaries and contents of this space by microdissection. Twenty-three en bloc preserved adult cadaveric specimens of the CCJ were dissected to identify the boundaries and contents of the supraodontoid space. The posterior bony elements of the CCJ were removed to enable microdissection (Zeiss DXE Microscope 4-40x) from the tectorial membrane (TM) forwards. The cave-like space faced posteriorly. It had a roof which extended into a wall (anterior atlanto-occipital membrane), a floor (superior surface of the alar ligament), and a mouth covered by the TM. The apical ligament and a thin lining membranous fatty layer divided the cave into a pair of symmetrical halves. The contents, from dorsal to ventral, lay deep to a thin subtectorial membrane. These were the superior fasciculus of the cruciate ligament, a fat-ensheathed knot of plexiform veins (which communicated with the surrounding CCJ vertebral venous plexuses), an arterial arcade between the veins, a pair of fat pads, and branches of the sinuvertebral nerves of the CCJ (lying on the floor). No synovial membrane was found. Knowledge of the anatomy of the apical cave may be of some assistance in transoral (extra- and transdural) surgical approaches to the anterior CCJ region.

The erector spinae plane block is a novel interfascial regional anesthetic technique initially described for management of acute and chronic thoracic pain. 1 Since its inception, the erector spinae plane block has been used for various truncal surgeries with success in both adults and children. 2 The therapeutic effect is attributed to the craniocaudal spread of local anesthetic over multiple vertebral levels within the tissue plane deep to the erector spinae muscle. It is also hypothesized that the interfascial spread blocks the ventral

Background The erector spinae plane block (ESP) is a novel approach for blockade of the spinal nerves in infants, children, and adults. Until recently, the gold standard for truncal procedures includes the paravertebral and epidural blocks. However, the exact mechanism by which this blockade is achieved is subject to debate. Methods 2.3 mL (1 mL/kg) of iodinated contrast dye was injected bilaterally into the erector spinae fascial plane of a fresh unembalmed preterm neonatal cadaver (weighing 2.3 kg), to replicate the erector spinae plane block and to track the cranio‐caudal spread of the contrast dye using computed tomography. The “block” was performed at vertebral level T8 on the right‐hand side and at vertebral level T10 on the left‐hand side. Results Contrast dye was spread over three dermatomal levels from T6 to T9 on the right‐hand side, while on the left‐hand side, the spread was seen over four dermatomal levels from T9 to T11/12. Contrast dye also spread over the costotransverse ligament, into the paravertebral space and further lateral from the lateral border of the erector spinae muscle into the intercostal space. However, no spread was seen in the epidural space. Conclusion The erector spinae plane block is a versatile technique that can be part of the multimodal postoperative analgesic strategy for truncal surgery. In this study, contrast material dye was tracked over four vertebral levels in the paravertebral space (suggesting an approximate volume of 0.5‐0.6 mL per dermatome).