[Attainment of the Lessinvasive Neurospinal Surgery: Full Endoscopic Spinal Surgery].

Full endoscopic spinal surgery(FESS)is the the least invasive surgery among the current spinal surgeries. FESS approach can be used to perform discectomy, decompression for stenosis, posterolateral fusion, etc. with little destruction of the spinal structure and posterior supporting elements, under local or general anesthesia. A major difference from conventional spinal surgeries is "underwater surgery," in which surgery is performed under continuous saline irrigation. In addition, for neurosurgeons, there is a steep learning curve to becoming proficient in using a small diameter endoscope for full-endoscopic surgery as well as performing treatment with the surgical field completely. We would like to explain the indication and surgical procedure of the transforaminal approach, then introduce decompression by FESS at the cervical spine level as well as full endoscopic lateral lumbar interbody fusion(ELIF).

Quantitative evaluation for cervical foraminal bony stenosis based on angled sagittal slices along a nerve root on computed tomography.

Cervical foraminal canal stenosis is a common disease, but any relationships between the measurement values of cervical foraminal canals and clinical symptoms have yet to be explored. We aim to determine a numerical cutoff point of cervical foraminal bony canal size that does not lead to radiculopathy so as to establish criteria for the surgical indication. We reconstructed angled sagittal slices along a nerve root on computed tomography (CT) on a workstation from pre-operative CT data and measured 1152 cervical foraminal canals (144 patients) from Cervical (C) 4/5 to C7/Thoracic (Th) 1. We evaluated the relationship between the size of foraminal canals and clinical manifestations. Receiver operating characteristic (ROC) analysis was used to calculate cutoff points of each foraminal canal size with positive neurologic manifestations. Of the 144 patients' 1152 nerve roots, 286 nerve roots (24.8%) were diagnosed as radiculopathy by neurological examinations. The mean measured value of all foraminal canals on angled sagittal CT imagery was 3.39 ±â€¯1.37 mm. The cutoff point of foraminal canal sizes without radiculopathy was 2.7 mm (sensitivity 0.680, specificity 0.591) overall. A cutoff point ascertained by quantitative evaluation of cervical foraminal canal size is useful for making diagnosis of cervical foraminal canal bony stenosis.

Dural Laceration Resulting in the Formation of Syringomyelia Caused by a Loosened Hydroxyapatite Intraspinous Spacer after Spinous Process-splitting Laminoplasty.

A 63-year-old man was admitted in our hospital with the chief complaint of upper limb numbness 3 years after undergoing spinous process-splitting laminoplasty (C3-C7) in another hospital. The hydroxyapatite spacers used for the laminoplasty had dislocated, resulting sensory disorders of the upper extremities. Additionally, loosened hydroxyapatite intraspinous spacers and syringomyelia were confirmed. A revision operation was performed, during which the C5 spacer was observed to have dislodged into the spinal canal, and a dural membrane defect, arachnoid membrane tear, cerebrospinal fluid leakage, and marked adhesion change were observed. The adhesion was exfoliated as far as possible; moreover, to prevent the reflux of syringomyelia, a syrinx-subarachnoid shunt (SS shunt) was placed. Although there was concern of further adhesion by putting foreign matter, SS shunt indwelling was chosen to obtain sure disappearance of syringomyelia. The postoperative course was uneventful. A gradual improvement in the upper limb numbness was observed without a recurrence of syringomyelia at 9 years of follow-up.

Activated microglia inhibit axonal growth through RGMa.

By causing damage to neural networks, spinal cord injuries (SCI) often result in severe motor and sensory dysfunction. Functional recovery requires axonal regrowth and regeneration of neural network, processes that are quite limited in the adult central nervous system (CNS). Previous work has shown that SCI lesions contain an accumulation of activated microglia, which can have multiple pathophysiological influences. Here, we show that activated microglia inhibit axonal growth via repulsive guidance molecule a (RGMa). We found that microglia activated by lipopolysaccharide (LPS) inhibited neurite outgrowth and induced growth cone collapse of cortical neurons in vitro--a pattern that was only observed when there was direct contact between microglia and neurons. After microglia were activated by LPS, they increased expression of RGMa; however, treatment with RGMa-neutralizing antibodies or transfection of RGMa siRNA attenuated the inhibitory effects of microglia on axonal outgrowth. Furthermore, minocycline, an inhibitor of microglial activation, attenuated the effects of microglia and RGMa expression. Finally, we examined whether these in vitro patterns could also be observed in vivo. Indeed, in a mouse SCI model, minocycline treatment reduced the accumulation of microglia and decreased RGMa expression after SCI, leading to reduced dieback in injured corticospinal tracts. These results suggest that activated microglia play a major role in inhibiting axon regeneration via RGMa in the injured CNS.

Percutaneous vertebroplasty using hydroxyapatite blocks for the treatment of vertebral body fracture.

Vertebroplasty with hydroxyapatite blocks through a modified percutaneous approach was used to treat 30 patients with vertebral body fractures in 32 vertebral bodies between February 2003 and March 2007. The mean follow-up period was 16.6 months. The pain associated with this procedure, effects on adjacent vertebral bodies, and other complications were evaluated. The rate of recollapse after vertebroplasty was examined in 26 patients with 26 vertebral bodies treated and followed up for more than 3 months. Mean time of operation was 57 minutes and mean number of blocks used per vertebral body was 104. The mean visual analogue scale score was 7.0 preoperatively and 1.6 postoperatively. The mean decline in postoperative vertebral body height was 13%. New vertebral body fractures occurred postoperatively in 3 vertebral bodies in 2 patients. Leakage of blocks outside the vertebral body occurred in 2 patients during the operation, and after the operation in one patient, and the hydroxyapatite plug broke postoperatively in one patient. Hydroxyapatite blocks yielded good pain relief comparable to bone cement, with no serious complications such as a pulmonary embolism or leakage into the spinal canal, and are effective for percutaneous vertebroplasty.