Yoshitaka Hirano

Novel Dural Closure Technique Using Polyglactin Acid Sheet Prevents Cerebrospinal Fluid Leakage after Spinal Surgery

OBJECTIVE: Extradural or subcutaneous cerebrospinal fluid (CSF) leakage is a common complication after spinal surgery and is associated with the risks of poor wound healing, meningitis, and pseudomeningocele. Numerous methods to prevent postoperative CSF leakage are available, but pressure-tight dural closure remains difficult, especially with synthetic surgical membranes. The efficacy of a novel dural closure technique was assessed by detecting extradural or subcutaneous CSF leakage on magnetic resonance imaging. METHODS: The novel dural closure technique using absorbable polyglactin acid sheet and fibrin glue and the conventional procedure using only fibrin glue were evaluated retrospectively by identifying extradural or subcutaneous CSF leakage on magnetic resonance imaging scans in the acute (2–7 d) and chronic (3–6 mo) postoperative stages after spinal intradural surgery in 53 patients. RESULTS: The incidence of extradural and subcutaneous CSF leakage was significantly lower (P < 0.05) in the acute (20%) and chronic (0%) stages using polyglactin acid sheet and fibrin glue in 15 patients compared with that in the acute (81%) and chronic (24%) stages using only fibrin glue in 38 patients. One patient in the fibrin glue-only group required repair surgery for cutaneous CSF leakage. CONCLUSION: The combination of polyglactin acid sheet and fibrin glue can achieve water-tight closure after spinal intradural surgery and can minimize the risk of intractable postoperative CSF leakage. This simple, economical technique is recommended for dural closure after spinal intradural surgery.

β-Tricalcium phosphate promotes bony fusion after anterior cervical discectomy and fusion using titanium cages.

Study Design. Retrospective consecutive cohort study. Objective. To study the effectiveness of &bgr;-tricalcium phosphate (&bgr;-TCP) granules as a packing material in the titanium cages for anterior cervical discectomy and fusion (ACDF), compared with the conventional hydroxyapatite (HA) granules. Summary of Background Data. ACDF using titanium cages is a standard procedure for the treatment of cervical spinal degenerative diseases. Synthetic bone substitutes are widely used to pack the titanium cage to augment intervertebral bony fusion, but the efficacy has not been confirmed. Methods. Fusion condition was evaluated on lateral radiographs and computed tomography. Complete fusion of the treated segments was defined by three criteria: movement of the spinous process at flexion and extension positions of less than 3 mm, bony bridging between vertebral bodies, and absence of the halo around the titanium cage. The evaluation was performed at 6 months, 1 year, and 2 years after surgery. Results. Intervertebral fusion was studied in patients who underwent ACDF using &bgr;-TCP (93 segments of 57 patients) or HA (72 segments of 48 patients) packing of cylindrical titanium cages. Complete fusion rate at 6 months and 1 year was significantly better in the &bgr;-TCP group (46% at 6 months and 69% at 1 year) than in the HA group (24% at 6 months and 49% at 1 year), but the rate was similar at 2 years in the &bgr;-TCP group (94%) and the HA group (90%). There were no material-related adverse effects. Conclusion. Satisfactory final fusion rates were obtained after ACDF using both &bgr;-TCP- and HA-packed titanium cages. &bgr;-TCP showed higher fusion rate in the early stage after surgery and can be recommended as a bone substitute for ACDF with titanium cages.

Angiographically occult spinal dural arteriovenous fistula located using selective computed tomography angiography. Case report.

Spinal dural arteriovenous fistula (DAVF) is the most common type of spinal arteriovenous malformation and may cause progressive myelopathy but is usually treatable in the early stages by direct surgery or intravascular embolization. Selective spinal angiography has been the gold standard for diagnosis, but angiographically occult DAVF is not uncommon. A 67-year-old man presented with a 2-year history of progressive paraparesis. Magnetic resonance (MR) imaging demonstrated segmental atrophy of the spinal cord and dilated coronary veins on the dorsal surface of the spinal cord. A DAVF was suspected, but repeated selective angiography failed to demonstrate the fistula. Findings from spoiled gradient echo MR imaging suggested that the draining vein flowed into the dilated venous plexus at the T-9 level. Selective computed tomography (CT) angiography of the right T-9 intercostal artery confirmed the location of the fistula. The authors successfully occluded the draining vein through surgery, and they observed that the fistula was low flow. The patient exhibited improvement in his symptoms, and postoperative MR imaging confirmed closure of the fistula. Selective CT angiography is useful in locating the draining vein of angiographically occult DAVF and therefore minimizing the extent of the surgical procedure.

Spontaneous C1 anterior arch fracture as a postoperative complication of foramen magnum decompression for Chiari malformation type 1.

Background: C1 fracture accounts for 2% of all spinal column injuries and 10% of cervical spine fractures, and is most frequently caused by motor vehicle accidents and falls. We present a rare case of C1 anterior arch fracture following standard foramen magnum decompression for Chiari malformation type 1. Case Description: A 63-year-old man underwent standard foramen magnum decompression (suboccipital craniectomy and C1 laminectomy) under a diagnosis of Chiari malformation type 1 with syringomyelia in June 2009. The postoperative course was uneventful until the patient noticed progressive posterior cervical pain 5 months after the operation. Computed tomography of the upper cervical spine obtained 7 months after the operation revealed left C1 anterior arch fracture. The patient was referred to our hospital at the end of January 2010 and C1–C2 posterior fusion with C1 lateral mass screws and C2 laminar screws was carried out in March 2010. Complete pain relief was achieved immediately after the second operation, and the patient resumed his daily activities. Conclusion: Anterior atlas fracture following foramen magnum decompression for Chiari malformation type 1 is very rare, but C1 laminectomy carries the risk of anterior arch fracture. Neurosurgeons should recognize that fracture of the atlas, which commonly results from an axial loading force, can occur in the postoperative period in patients with Chiari malformation.

Recapping hemilaminoplasty for spinal surgical disorders using ultrasonic bone curette

Objective: The authors present a novel method of the recapping hemilaminoplasty in a retrospective study of patients with spinal surgical disorders. This report describes the surgical technique and the results of hemilaminoplasty using an ultrasonic bone curette. The aim of this study was to examine the safety and effectiveness of the hemilaminoplasty technique with ultrasonic bone curette. Methods: Between April 2003 and July 2011, 33 patients with various spinal diseases (17 spinal tumors, 5 dural arteriovenous fistulas, 3 syringomyelia, 2 sacral perineural cysts, and 2 arachnoid cysts) were treated microsurgically by using an ultrasonic bone curette with scalpel blade and lightweight handpiece. The ultrasonic bone curette was used for division of lamina. After resection of the lesion, the excised lamina was replaced exactly in situ to its original anatomic position with a titanium plate and screw. Additional fusion technique was not required and the device was easy to handle. All patients were observed both neurologically and radiologically by dynamic plain radiographs and computed tomography (CT) scan. Results: The operation was performed successfully and there were no instrument-related complications such as dural laceration, nerve root injury, and vessels injury. The mean number of resected and restored lamina was 1.7. CT confirmed primary bone fusion in all patients by 12 months after surgery. Conclusion: The ultrasonic bone curette is a useful instrument for recapping hemilaminoplasty in various spinal surgeries. This method allows anatomical reconstruction of the excised bone to preserve the posterior surrounding tissues.

History and Evolution of Laminoplasty

Techniques of expansive laminoplasty for degenerative cervical myelopathy and ossified posterior longitudinal ligament are described, focusing on the history of the surgical procedure. Laminectomy was the only approach for posterior decompression before Japanese orthopedic surgeons introduced laminoplasty from the 1970s to the 1980s to overcome the poor outcomes of laminectomy. Recent laminoplasty techniques offer less invasive maneuvers to the posterior cervical muscle structures to reduce axial neck pain and to obtain better functional outcome, but every operation is carried out based on the unchanged initial concept. Some recent attempts to improve the surgical results are also discussed.

Surgical management of symptomatic ossified anterior longitudinal ligament: A case report

Background: Ossified anterior longitudinal ligament (OALL) of the cervical spine can cause dysphagia, dyspnoea, and dysphonia, although these symptoms are rare. Case Description: A 71-year-old male presented with gradually progressive dysphagia secondary to OALL. He underwent fiber optic endoscopy and lateral video fluoroscopy. The OALL extended from C4 to C7 and contributed to significant compression of the pharynx as demonstrated on plain cervical radiography, magnetic resonance (MR) imaging, and computed tomography (CT). Following microsurgical resection of the OALL, his symptoms improved. Conclusions: This study focuses on the clinical and radiographic presentation of OALL; the latter utilizing plain X-rays, MR, and CT studies. Notably, surgical resection is straightforward and allows for immediate decompression of the pharynx as long as it is truly the symptomatic problem.

Initial radiological findings utilizing titanium basket for cervical open door laminoplasty

Background: Cervical laminoplasty, utilizing different spacers to ’’keep the door open,’’ is the gold standard in Japan for treating ossification of the posterior longitudinal ligament (OPLL) and cervical spondylotic myelopathy (CSM). Here, we utilized a novel titanium ’’basket’’ spacer (Laminoplasty Basket: L-Basket; Ammtec, Tokyo) to perform open door cervical laminoplasty to keep the “door open” while also allowing for bony fusion across the open door. Methods: Twenty-seven patients with/without OPLL were treated with open door laminoplasty utilizing the basket spacer. Patients were analyzed with preoperative/postoperative JOA scores, and X-rays/computed tomography (CT) at least 12 months (range, 12–19 months) postoperatively. Results: Improvement from the preoperative JOA score of 10.3 points to the postoperative JOA of 14.8 points was noted 3 months postoperatively. There were no complications except one patient who had transient C5 palsy. Twelve months postoperatively, X-rays/CT documented fusion on both the open (62%) and hinge sides (90.2%); circumferential fusion was observed 59.8% of the time. Conclusion: This titanium “basket” spacer (Laminoplasty Basket: L-Basket; Ammtec, Tokyo) promoted bone union between the spacer and both lamina, lateral masses following cervical laminoplasty without undue complications.

Limaprost Alfadex Improves Myelopathy Symptoms in Patients With Cervical Spinal Canal Stenosis

Study Design. Myelopathy symptoms were prospectively studied in patients with cervical spinal canal stenosis (CSCS), using objective grading systems and stabilometry, to examine the effect of administration of prostaglandin E1 derivative limaprost alfadex (limaprost). Objective. Myelopathy scores/grades and stabilometry parameters were evaluated before, and 1 and 3 months after starting the limaprost treatment. Summary and Background Data. Limaprost is a potent vasodilator and antiplatelet agent and has been used to treat the symptoms of lumbar spinal canal stenosis. The action presumably involves increased blood flow in the compressed cauda equina. Limaprost can also increase blood flow in the compressed spinal cord, but effects on myelopathy symptoms in patients with CSCS have not been established. Methods. This study examined 21 patients with mild spondylotic CSCS based on neurologic findings and compression of the cervical spinal cord on magnetic resonance imaging. Japanese Orthopedic Association score, grip and release test, and finger escape sign were measured, and stabilometry was performed by independent examiners, before, and 1 and 3 months after starting the oral limaprost treatment. Results. Most patients experienced amelioration of the symptoms at 1 month after starting the treatment. Mean Japanese Orthopedic Association score and grip and release count were significantly improved and finger escape sign grade was higher in some patients. Stabilometry area with eyes closed and Romberg rate were also significantly improved. These improvements were maintained at 3 months. Conclusion. The efficacy of oral limaprost administration for patients with CSCS was confirmed by objective scoring and quantitative data.

Surgical Treatment of Syringomyelia Associated with Chiari I Malformation: Advantage of Cranioplasty Using Hydroxyapatite Implants

Suboccipital craniectomy (SOC) for the treatment of syringomyelia associated with Chiari I malformation has been routinely performed to improve clinical symptoms. A retrospective study was conducted of eight patients who underwent SOC followed by cranioplasty with hydroxyapatite (HA) implants. Neurological impairments and radiological findings based on magnetic resonance imaging (MRI) were assessed preoperatively and at a mean 13.3-month follow-up. The six female and two male patients ranged in age from 9 to 66 years (mean, 41.4 years). Each patient exhibited varying degrees of sensory discomfort of the extremities. Computed tomography study in one case with an intramedullary lesion revealed a cerebrospinal fluid (CSF) density, and the patient was diagnosed with syringomyelia. Operations were performed through SOC and upper cervical laminectomies. Duraplasty using Gore-Tex or resection of the outer layer of the dura was selected under intraoperative ultrasound echography. Subsequently, the decompressed foramen magnum was covered with a curved plate of HA and tenting sutures of the dura were added. Neurological impairments improved in five of eight patients and persisted in three cases. Postoperative MRI showed diminution in the size of the syrinx and the ascent of the cerebellar tonsils in seven of eight cases. Three-dimensional computed tomography (3D-CT) in some patients revealed bone fusion of HA with the adjacent occipital bone within 6 months after surgery. In conclusion, the findings in this study showed HA cranioplasty has the advantage of early securement of the retrotonsillar subarachnoid space and preclusion of epidural CSF retention.