Clinical and Radiologic Analysis of Posterior Apophyseal Ring Separation Associated with Lumbar Disc Herniation

OBJECTIVE: We analyzed the clinical and radiologic features of posterior apophyseal ring separation (PARS) with lumbar disc herniation and suggest the proper management options according to the PARS characteristics. METHODS: We reviewed case series of patients with PARS who underwent surgery of lumbar disc herniation. Preoperative symptoms, neurologic status, Body Mass Index, preoperative and postoperative Visual Analogue Scale (VAS) and Korean-Oswestry Disability Index (K-ODI) scores, operation types were obtained. PARS size, locations, the degree of resection were assessed. RESULTS: PARS was diagnosed in 109 (7.5%) patients among 1448 patients given surgical treatment for single level lumbar disc herniation. There were 55 (50.5%) small PARS and 54 (49.5%) large PARS. Among the large PARS group, 15 (27.8%) had lower endplate PARS of upper vertebra at the level of disc herniation. Thirty-nine (72.2%) were upper endplate PARS of lower vertebra. Among the group with upper endplate PARS of lower vertebra, unresected PARS was diagnosed in 12 (30.8%) cases and resected PARS was diagnosed in 27 (69.2%) cases. VAS and K-ODI scores changes were 3.6+/-2.9 and 5.4+/-6.4 in the unresected PARS group, 5.8+/-2.1 and 11.3+/-7.1 in the resected PARS group. The group with upper endplate PARS of lower vertebra showed significant difference of VAS (p=0.01) and K-ODI (p=0.013) score changes between unresected and resected PARS groups. CONCLUSION: The large PARS of upper endplate in lower vertebra should be removed during the surgery of lumbar disc herniation. High level or bilateral side of PARS should be widely decompressed and arthrodesis procedures are necessary if there is a possibility of secondary instability.

Ganglion Cyst of the Posterior Longitudinal Ligament Causing Lumbar Radiculopathy

Degenerated conditions such as herniated disc or spinal stenosis are common etiologies of lumbar radiculopathy. Less common etiologies include spinal extradural cyst such as synovial cysts and ganglion cysts. Ganglion cyst of the posterior longitudinal ligament (PLL) of the spine is a rare entity that can result in classical sciatica. Posterior longitudinal ligament cyst has no continuity with the facet joint and has no epithelial lining. Two young male patients presented with unilateral sciatica and were found to have intraspinal cystic lesions causing lumbar radiculopathy. Magnetic resonance imaging demonstrated rounded, cystic lesions (i.e., hypointense on T1- but hyperintense on T2-weighted images) adjacent to minimally dehydrated, nonherniated disc spaces in both cases. These patients underwent posterior decompression and cysts were excised, and their sciatic symptoms were completely resolved. Histological examination showed typical features of ganglion cysts in these cases.

Lumbar Intraspinal Extradural Ganglion Cysts

The lumbar intraspinal epidural ganglion cyst has been a rare cause of the low back pain or leg pain. Ganglion cysts and synovial cysts compose the juxtafacet cysts. Extensive studies have been performed about the synovial cysts, however, very little has been known about the ganglion cyst. Current report is about two ganglion cysts associated with implicative findings in young male patients. We discuss about the underlying pathology of the ganglion cyst based on intraoperative evidences, associated disc herniation at the same location or severe degeneration of the ligament flavum that the cyst originated from in young patients.

Computerized Tomographic Measurements of Morphometric Parameters of the C2 for the Feasibility of Laminar Screw Fixation in Korean Population

OBJECTIVE: C2 laminar screw fixation is considered as an excellent alternative to Magerl's transfacetal approach or Harms construct for the atlantoaxial stabilization. However, to our knowledge, there is no report on the feasibility of the new approach to Korean population. We investigated morphometric parameters of the dorsal arch of the C2 to provide the quantitative data for the feasibility of laminar screw fixation. METHODS: One-hundred-and-two patients' cervical computed tomography had been reconstructed and investigated on the anatomical parameters related with C2 laminar screw placement. Sixty patients were male and forty-two patients were female. Measurements included the laminar thickness and slope, spino-laminar angle, and maximal screw length. RESULTS: Ages ranged from 20 to 81 and the mean age was 48.4. Mean laminar thickness was 5.7 mm (+/-1.0) (5.8 mm in male and 5.4 mm in female). Fifty-one patients (50%) had a laminar thickness smaller than 5.5 mm at least unilaterally, therefore the patients were considered as inappropriate candidates for the laminar screw fixation in the smaller side of the laminae. Mean value of maximal length of screw was 33.3 mm (34.3 mm in male and 31.9 mm in female). Mean spino-laminar angle was 43.2degrees and mean slope angle was 32.9degrees. CONCLUSION: Half of patients had inappropriate laminar profiles to accommodate a 3.5 mm screw in at least one side of the axis. The three-dimensional computed tomography reconstruction is mandatory for the preoperative assessment for the feasibility of the C2 lamina.

Troublesome Occipital Neuralgia Developed by C1-C2 Harms Construct

Recently, Harms and Melcher modified Goel's approach, the C1 lateral mass and C2 pedicle screw fixation, and the new technique is currently in favor among neurosurgeons. Comparing to the advantages of Harms construct, the disadvantages were not extensively investigated. We experienced a patient with severe occipital pain developed after the C1 lateral mass screw placement for the traumatic atlantoaxial instability. We reviewed literatures about Harms construct with focus on the occipital neuralgia as a postoperative complication and suggest here technical tips to avoid the troublesome pain.

Modified Trajectory of C2 Laminar Screw - Double Bicortical Purchase of the Inferiorly Crossing Screw

The crossing laminar screw fixation might be the most recently developed approach among various fixation techniques for C2. The new construct has stability comparable to transarticular or transpedicular screw fixation without risk of vertebral artery injury. Quantitative anatomical studies about C2 vertebra suggest significant variation in the thickness of C2 lamina as well as cross sectional area of junction of lamina and spinous process. We present an elderly patient who underwent an occipito-cervical stabilization incorporating crossed C2 laminar screw fixation. We preoperatively recognized that she had low profiles of C2 lamina, and thus made a modification of trajectory for the inferiorly crossing screw. We introduce a simple modification of crossing C2 laminar screw technique to improve stability in patients with low laminar profiles.

Bilateral Vertebral Artery Dissecting Aneurysms: A Long Term Follow-up Results of Microsurgical Trapping and Proximal Occlusion

Regarding the bilateral vertebral artery (VA) dissecting aneurysms, treatment strategy remains controversial because there have not been enough cases to reach a conclusion on the best treatment. We present a patient underwent staged microsurgical trapping and endovascular coiling for each dissecting aneurysm of bilateral VA presenting subarachnoid hemorrhage (SAH). The ruptured side was managed by VA trapping procedure without any neurological deficit. Postoperative cerebral angiography revealed patent right PICA without filling of previous right dissecting aneurysm and spontaneous occlusion of the left dissecting aneurysm one month after trapping procedure. However, follow-up angiography revealed recanalization and growing of the left VA dissecting aneurysm one year after the operation. The patient underwent endovascular embolization using GDC for the proximal occlusion of the left VA and postoperative course was uneventful.

Lumbo-sacro-pelvic Fixation Using Iliac Screws for the Complex Lumbo-sacral Fractures

Fractures of lumbo-sacral junction involving bilateral sacral wings are rare. Posterior lumbo-sacral fixation does not always provide with sufficient stability in such cases. Various augmentation techniques including divergent sacral ala screws, S2 pedicle screws and Galveston rods have been reported to improve lumbo-sacral stabilization. Galveston technique using iliac bones would be the best surgical approach especially in patients with bilateral comminuted sacral fractures. However, original Galveston surgery is technically demanding and bending rods into the appropriate alignment is time consuming. We present a patient with unstable lumbo-sacral junction fractures and comminuted U-shaped sacral fractures treated by lumbo-sacro-pelvic fixation using iliac screws and discuss about the advantages of the iliac screws over the rod system of Galveston technique.

The Incidence of Aneurysmal Subarachnoid Hemorrhage in Youngdong District, Korea

OBJECTIVE: The purpose of this study is to investigate the incidence of aneurysmal subarachnoid hemorrhage (SAH) in Youngdong district for 10 years. METHODS: From Jan. 1997 to Dec. 2006, 732 patients (327 males, 405 females, mean age: 54.8+/-13.1 years) with spontaneous SAH were admitted to our hospital. We reviewed the medical records and radiological findings regarding to the ictus of SAH, location and size of the ruptured aneurysms, Hunt-Hess grade and Fisher grade on admission, personal details such as address, age, and sex, and previous history of medical diseases. RESULTS: In these 732 patients, 672 cases were confirmed as aneurysmal SAH. Among them, 611 patients (262 males, 349 females, mean age: 54.9+/-13.2 years) came from Youngdong district. The average crude annual incidence of aneurysmal SAH for men, women, and both sexes combined in Youngdong district was 7.8+/-1.7, 10.5+/-2.7, and 9.1+/-2.1 per 100,000 population, respectively. Because of the problems related to the observation period and geographical confinement, it was suspected that the representative incidence of aneurysmal SAH in Youngdong district should be made during the later eight years in six coastal regions. Therefore, the average age-adjusted annual incidence for men, women, and both sexes combined was 8.8+/-1.4, 11.2+/-1.3 and 10.0+/-1.0, respectively in the coastal regions of Youngdong district from 1999 to 2006. CONCLUSION: In overall, our results on the incidence of aneurysmal SAH was not very different from previous observations from other studies.

The Dissecting Aneurysm of the Posterior Inferior Cerebellar Artery with Unusual Clinical Course

The dissecting aneurysms of the posterior cerebral circulation arise most commonly from the vertebral artery and occasionally extend to the posterior inferior cerebellar artery(PICA). The dissecting aneurysm localized in the PICA without involving the vertebral artery is rare. We present a PICA dissecting aneurysm that had kaleidoscopic clinical course of bleeding, occlusion, and recanalization before the surgery. The patient had serial follow-up angiograms based on significant changes of clinical status. The patient successfully underwent microsurgical trapping with clips for the dissecting aneurysm and showed neurological improvement.

Therapeutic Results of Posterior Fossa Tumors with Hydrocephalus

OBJECTIVE: This study is designed to identify the clinical characteristics and the optimal treatment modality of hydrocephalus in posterior fossa tumors. METHODS: The authors reviewed 154 infratentorial tumor patients. Age, sex, clinical symptoms, types of treatment, and surgical results of posterior fossa tumor patients with hydrocephalus were analyzed, retros-pectively. Factors which might predict the need for external ventricular drainage(EVD) or ventriculo-peritoneal shunt were analyzed statistically. RESULTS: Hydrocephalus was noted in 86 cases(56%), and it was associated with medulloblastoma in 16 cases(89%), hemangioblastoma in 12(63%) and brain stem glioma in three(33%). The surgical results of the posterior fossa tumors with hydrocephalus were poorer than those without hydrocephalus(p<0.05). A large tumor(p<0.05) and an incomplete removal(p<0.05) were factors predicting the need for EVD or shunt. Complications of intraoperative EVD or shunt developed in four cases. They were infection, he-morrhage at puncture site, and obstruction. Five patients in whom intraoperative EVD or shunt had not been performed developed a fatal hydrocephalic attack at immediate postoperative period, and the pos-toperative computed tomography scan revealed intraventricular hemorrhages in three cases cerebellar swellings in two cases. CONCLUSION: Intraoperative EVD or shunt is a safe, effective treatment modality especially in large size tumor and/or incomplete tumor resection. Intraventricular hemorrhages or cerebellar swellings during immediate postoperative period might cause fatal hydrocephalic attack, therefore EVD or shunt might be recommended in selected cases.

Posterior Lumbar Interbody Fusion Versus 360degrees Fixation in Degenerative Lumbar Diseases

OBJECTIVES: The goal of operation for degenerative lumbar diseases is to relieve radiculopathy and low back pain and to prevent further degeneration. The authors analyzed the surgical results of posterior lumbar interbody fusion(PLIF) and 360degrees fixation to evaluate the proper treatment policy in spinal stenosis, degenerative spondylolisthesis and low grade isthmic spondylolisthesis. MATERIAL AND METHODS: The authors performed PLIF on 92 patients and 360degrees fixation on 138 patients with spinal stenosis, degenerative spondylolisthesis and low grade isthmic spondylolisthesis. We retrospectively studied clinical outcomes and subjective satisfaction of these patients by several criteria such as visual analog scale(VAS), Prolo's economic and functional outcome scale, medication usage after operation and questionaire for overall outcome. RESULT: Pre- and postoperative VAS on back pain and leg pain showed decrease of pain from 6.5, 6.7 to 2.2, 2.4 in PLIF group and from 7.0, 7.2 to 2.5, 2.7 in 360degrees fixation group. Excellent and good outcomes on Prolo's scale were 81.5% in PLIF group and 82.6% in 360degrees fixation group. Medication usage after operation was reduced in 79.3% of PLIF group and in 78.3% of 360degrees fixation group. Patients' self-reported overall success of their procedure showed 82% in PLIF group and 84% in 360degrees fixation group. CONCLUSION: Both PLIF and 360degrees fixation showed good outcomes and provided biomechanically stable fusion in spinal stenosis, degenerative spondylolisthesis and low grade isthmic spondylolisthesis. Therefore, only PLIF seems necessary and considered a proper surgical treatment for these disorders.

Indications of Postoperative Angiography after Surgical Treatment of Intracranial Aneurysms

OBJECTIVE: Subarachnoid hemorrhage(SAH) is still one of the most serious disease with high morbidity and mortality in the neurosurgical field. Clipping of the aneurysmal neck is the gold standard of the surgical treatment of aneurysmal SAH. The purpose of this study was to investigate the role of the postoperative angiography and to assess the risk factors related to the incomplete clipping. MATERIALS AND METHODS: From July 1995 to June 1998, the pre- and postoperative angiography were performed in 50 patients among total 81 patients who have underwent the aneurysmal surgery. We reviewed the various contributing factors including age, sex, Hunt-Hess grade, Fisher grade and the premature rupture of aneurysm during operation retrospectively. Careful evaluation of pre- and postoperative angiography focusing on the size, shape, and remnant neck of the aneurysms and vasospasm was performed. According to the angiographic findings, the patients were divided into two groups; a complete clipping group and an incomplete clipping group. The data were analyzed by using unpaired independent sample t test after F-test to compare the significance between two groups. RESULTS: Incomplete clipping of aneurysms was found in 6(12%) patients through the evaluation of postoperative angiography. Among them, three cases were located on the middle cerebral artery territory. Whereas the patient age, sex, Hunt-Hess grade, and Fisher grade were not significant(p<0.05), an intraoperative premature rupture had a statistical significance(p<0.05). A severe vasospasm occurred in 24(48%) cases and one patient with anterior communicating aneurysm was reoperated due to residual sac. CONCLUSION: According to our experience, the surgeons' judgement is the most reliable factor in deciding the postoperative angiography. During the aneurysmal surgery, the premature rupture always disturbs a complete clipping of aneurysms. Therefore, the temporary clipping of parent arteries is considered essential for a successful clipping. We believe that the postoperative angiography has a role in decreasing the re-bleeding risk due to clip migration and an inaccurate clipping only in the selected cases.

Transsphenoidal Supradiaphragmatic Intradural Approach - Technical Note -

OBJECTIVE: Various lesions including tumors occupying in the presellar and suprasellar regions have been traditionally removed by the transcranial approach. The new modified transsphenoidal approaches(TSAs) have been proposed to avoid the craniotomy and to get better surgical view. MATERIALS AND PATIENTS: The sellar floor and presellar anterior cranial fossa were removed through the sublabial transseptal transsphenoidal technique in the "transsphenoidal supradiaphragmatic intradural approach". One tuberculum sella meningioma and a suprasellar Rathke's cleft cyst confined to the pituitary stalk were removed via this approach. RESULTS: The dissection of the anterior intercavernous sinus, diaphragma sella, and arachnoid membrane allowed a wide surgical field of pre- and suprasellar areas and facilitated a safe removal of lesions without significant surgical complications in our cases. CONCLUSION: From the authors' limited experience, the advantages of this technique are as follows: 1) it can be easily applicable through a minor modification of the standard TSA, 2) excellent anatomical exposure of the structures located in the supradiaphragmatic suprasellar cistern, and 3) might be suitable to remove small lesions located in the presellar and adjacent to the pituitary stalk region.