Although chemonucleolysis with chymopapain is a long-established treatment for lumbar intervertebral disc herniation, serious complications have been reported. Accordingly, alternative substances for chemonucleolysis have been sought. The main beneficial effect of chemonucleolysis derives from the decrease in intradiscal pressure. Several previous studies have investigated the relationship between physiological saline injection and disc mechanics in cadaveric specimens [2, 5, 16]. However, no previous study has assessed the intradiscal pressure after intradiscal injection of "hypertonic saline" in living animals. The present study compared the changes in intradiscal pressure after intradiscal injection of hypertonic saline with those after chymopapain injection. The lumbar intervertebral discs of 26 living rabbits were examined: 10% hypertonic saline was injected in ten rabbits, and chymopapain (10 pikokatal units) was injected intradiscally in another ten, with the remaining six being used as controls. The intradiscal pressure was measured at 1, 4, and 12 weeks after injection. The intradiscal pressure of the hypertonic saline-injected group at 4 weeks was significantly lower than that of the control group, but by 12 weeks it had recovered. On the other hand, that of the chymopapain-injected group remained significantly lower than that of the control group at 12 weeks. The results of this study found that hypertonic saline injected into the intervertebral discs temporarily decreased the intradiscal pressure.

This study was conducted to analyze the findings and benefits of computed tomography (CT) epidurography in patients with low back and leg pain and compare these findings with those of magnetic resonance imaging (MRI) images. In total, 495 intervertebral discs from 99 patients with low back and leg pain who underwent percutaneous epidural adhesiolysis (epidural neuroplasty or percutaneous adhesiolysis) were examined. The axial views of CT epidurography were classified into six types to examine each intervertebral disc: round type, ellipse type, spike type, Benz mark, incomplete block, complete block, and non-contrast. MRI images were graded from A to D using the Schizas classification. Notably, 176 images were round-type and ellipse-type axial views, and 138 were spike-type and Benz-mark views; Schizas classification Grades A and B were observed in 272 and 47 MRI images, respectively. The incomplete block and complete block axial images did not significantly differ in CT epidurography and Schizas classification Grades C and D. The images showing Benz marks existed only at the L4/5 and L5/S intervertebral levels and only in 14.7% of patients. The ratio of normal shadows differed between MRI images and CT epidurography. Therefore, CT epidurography may enable a detailed evaluation of the epidural space.

Objective Intraoperative neurophysiologic monitoring (IONM) reportedly contributes to preventing postoperative neurological complications in high-risk spinal cord surgeries. There are both negative and positive reports about IONM for intradural extramedullary (IDEM) tumors. We investigated factors affecting alerts of IONM in IDEM tumor surgery. Methods We analyzed 39 patients with IDEM tumors who underwent surgery using IONM at our hospital between January 2014, and March 2021. Neurological symptoms were evaluated pre- and postoperatively using the manual muscle test (MMT). All patients were evaluated to ascertain the tumor level and location in the axial view, the operative time, intraoperative bleeding volume, and histological type. Additionally, the intraoperative procedure associated with significant IONM changes in transcranial electrical stimulation muscle evoked potential was investigated. Results There were 11 false-positive and 26 true-negative cases. There was one true-positive case and one false-negative case; the monitoring accuracy achieved a sensitivity of 50%, specificity of 70%, a positive predictive value of 8%, and a negative predictive value of 96%. In the analysis of 22 alert cases, if the tumor was located anterolateral in the axial view, alerts were triggered with a significant difference (p = 0.02) during tumor resection. Fifteen patients generated alerts during tumor resection; nine (60%) showed waveform improvement by intervention and were classified as rescue cases. Conclusions Alert is probably triggered during tumor resection for anterolaterally located tumors. In addition, alerts during tumor resection procedures tended to be more likely to be rescued than other procedures in IDEM tumor surgery.

Intraoperative neurophysiologic monitoring (IONM) reportedly contributes to preventing postoperative neurological complications in high-risk spinal cord surgeries. There are both negative and positive reports about IONM for intradural extramedullary (IDEM) tumors. We investigated factors affecting alerts of IONM in IDEM tumor surgery. MethodsWe analyzed 39 patients with IDEM tumors who underwent surgery using IONM at our hospital between January 2014, and March 2021. Neurological symptoms were evaluated pre-and postoperatively using the manual muscle test (MMT).All patients were evaluated to ascertain the tumor level and location in the axial view, the operative time, intraoperative bleeding volume, and histological type. Additionally, the intraoperative procedure associated with signi cant IONM changes in transcranial electrical stimulation muscle evoked potential was investigated. ResultsThere were 11 false-positive and 26 true-negative cases. There was one true-positive case and one false-negative case; the monitoring accuracy achieved a sensitivity of 50%, speci city of 70%, a positive predictive value of 8%, and a negative predictive value of 96%. In the analysis of 22 alert cases, if the tumor was located anterolateral in the axial view, alerts were triggered with a signi cant difference (p = 0.02) during tumor resection. Fifteen patients generated alerts during tumor resection; nine (60%) showed waveform improvement by intervention and were classi ed as rescue cases. ConclusionsAlert is probably triggered during tumor resection for anterolaterally located tumors. In addition, alerts during tumor resection procedures tended to be more likely to be rescued than other procedures in IDEM tumor surgery.

No abstract