Prevalence and Anatomy of Aberrant Right Subclavian Artery Evaluated by Computed Tomographic Angiography at a Single Institution in Korea.

OBJECTIVE: Aberrant right subclavian artery (ARSA) is a rare anatomical variant of the origin of the right subclavian artery. ARSA is defined as the right subclavian artery originating as the final branch of the aortic arch. The purpose of this study is to determine the prevalence and the anatomy of ARSA evaluated with computed tomography (CT) angiography. METHODS: CT angiography was performed in 3460 patients between March 1, 2014 and November 30, 2015 and the results were analyzed. The origin of the ARSA, course of the vessel, possible inadvertent ARSA puncture site during subclavian vein catheterization, Kommerell diverticula, and associated vascular anomalies were evaluated. We used the literature to review the clinical importance of ARSA. RESULTS: Seventeen in 3460 patients had ARSA. All ARSAs in 17 patients originated from the posterior aspect of the aortic arch and traveled along a retroesophageal course to the right thoracic outlet. All 17 ARSAs were located in the anterior portion from first to fourth thoracic vertebral bodies and were located near the right subclavian vein at the medial third of the clavicle. Only one of 17 patients presented with dysphagia. CONCLUSION: It is important to be aware ARSA before surgical approaches to upper thoracic vertebrae in order to avoid complications and effect proper treatment. In patients with a known ARSA, a right transradial approach for aortography or cerebral angiography should be changed to a left radial artery or transfemoral approach.

Prevalence and anatomy of anomalous left vertebral artery originated from aorta evaluated by computed tomographic angiography.

PURPOSE: We evaluated anatomical characteristics and clinical significance of left vertebral artery (VA) originating from aortic arch (AA) by computed tomography (CT) angiography. METHODS: CT angiography was performed in 3460 patients between March 01, 2014 and November 30, 2015. We examined course of prevertebral VA (PVVA) segment and level of entry into the cervical vertebra transverse foramen (CVTF) of left VA originated from AA. RESULTS: One hundred fifty-three of 3460 patients had left VA originated from AA. Six of 153 patients had dual origin of VA. Entry level to CVTF of 156 left VAs in 153 cases ranged from C3 to C6. Entry level to CVTF of 156 right VAs in 153 cases ranged from C3 to C7. One hundred fifty-six right PVVA segments positioned in longus colli muscle lateral side in 112 VAs, longus colli muscle anterior surface near longus colli muscle lateral margin in 41 VAs, and unknown location in three VAs. One hundred fifty-six left PVVA segments positioned in anterior surface of longus colli muscle midline in 5 cases, anterior surface of longus colli muscle near longus colli lateral margin in 138 cases, longus colli muscle lateral side in 12 cases, and anterior surface of anterior scalene muscle midline in one case. CONCLUSIONS: Left VA may arise from the AA. If a long PVVA segment entering higher CVTF is present, operator can perform anterior cervical surgery via contralateral approach for avoidance of VA injury.

A Type 1 Persistent Proatlantal Artery Originating from the External Carotid Artery Detected by Computed Tomographic Angiography.

A persistent proatlantal artery (PA) is rare. We report a type 1 persistent PA originating from the right external carotid artery (ECA). A 78-year-old woman presented with dizziness. Computed tomographic (CT) angiography showed a persistent PA originating from the right ECA. This persistent PA did not pass through the atlas transverse foramen. The extracranial segment of this artery in the atlas transverse process level had a more lateral position than a normal left vertebral artery. CT angiography well demonstrated the relationship with bony structures and the course of this persistent PA. This anomalous artery in our patient presented as an incidental finding. Surgeon should recognize a persistent PA when performing carotid endarterectomy or ligation of the ECA for avoidance of complication.

An Affordable Microsurgical Training System for a Beginning Neurosurgeon: How to Realize the Self-Training Laboratory.

OBJECTIVE: To provide detailed information about how to realize a self-training laboratory with cost-effective microsurgical instruments, especially pertinent for the novice trainee. METHODS: Our training model is designed to allow the practice of the microsurgery skills in an efficient and cost-effective manner. A used stereoscopic microscope is prepared for microsurgical training. A sufficient working distance for microsurgical practice is obtained by attaching an auxiliary objective lens. The minimum instrument list includes 2 jeweler's forceps, iris scissors, and alligator clips. The iris scissors and alligator clip provide good alternatives to micro-scissors and microvascular clamp. RESULTS: The short time needed to set up the microscope and suture the gauze with micro-forceps makes the training model suitable for daily practice. It takes about 15 minutes to suture 10 neighboring fibers of the gauze with 10-0 nylon; thus, training can be completed more quickly. CONCLUSIONS: We have developed an inexpensive and efficient micro-anastomosis training system using a stereoscopic microscope and minimal micro-instruments. Especially useful for novice trainees, this system provides high accessibility for microsurgical training.

Tailored Double-Barrel Bypass Surgery Using an Occipital Artery Graft for Unstable Intracranial Vascular Occlusive Disease.

PURPOSE: This report describes the need for a tailored approach for intracranial vascular occlusive disease and introduces the usefulness of the OA as a donor artery for interposition graft. MATERIALS AND METHODS: A 65-year-old male patient suffered from repeated transient ischemic attack (TIA). Imaging studies revealed complete occlusion of the proximal left side of the internal carotid artery (ICA) and multiple infarction in the watershed zone. We planned superficial temporal artery-middle cerebral artery (STA-MCA) bypass to restore cerebral blood flow and to prevent the progression of infarction. However, the parietal branch of the STA was too small in diameter and not suitable as a single donor for the bypass in order to supply sufficient blood flow. Moreover, the frontal branch of the STA had collateral channels through the periorbital anastomosis into the cerebral cortex that could result in infarction during clamping for anastomosis. RESULTS: We determined that tailored treatment planning was necessary for successful revascularization under these conditions. Thus, we performed a bypass between the parietal branch of the STA and a cortical branch of the MCA as an "insurance bypass." Then we performed another bypass between the frontal branch of the STA and a cortical branch of the MCA using an ipsilateral occipital artery (OA) interposition graft. The patient had no perioperative complications, and postoperative imaging confirmed the restoration of cerebral blood flow. CONCLUSION: When end-to-side anastomosis in single-branch bypass is not appropriate for cerebral revascularization, a tailored double-barrel "insurance bypass" with an OA interposed graft could be a good alternative treatment modality. In addition, an OA interposition graft is a useful option for double-barrel bypass surgery in such cases of intracranial vascular occlusive disease.

A Technically Simple and Safe Method for Preparing an Anterior Pericranial Flap Using Saline Injection into the Subgaleal Space: A Technical Note.

BACKGROUND: Cranial defects following anterior cranial base surgery have been frequently reconstructed using the pericranial flap. METHODS: We present a simple technique for preparing the flap using injection of saline into the subgaleal space. RESULTS: We inserted a 20-gauge needle perpendicular to 8-10 spots in the frontal area and injected 5-7 mL of saline at each spot 10 minutes before skin incision. Distinctive swelling of the scalp was then observed. After the scalp was incised, the layers were dissected with a monopolar electrocautery device. The layer containing saline allowed us to better localize its exact position and harvest the flap without injury. Dissection in the subgaleal plane was performed mainly using the tip of a surgical blade. After the periosteum was stripped from the calvaria, the flap that had been considerably thickened by saline injection was harvested. CONCLUSIONS: Because pericranium thickness in the frontal areas is reported to be thinner than in other areas, a beginning neurosurgeon may have difficulty harvesting an anteriorly based flap of sufficient size. The technique presented here can help increase awareness of the subgaleal layer, facilitate the dissection process, and reduce additional tissue injury resulting from electrocautery manipulation.

A practical scoring system to determine whether to proceed with surgical resection in recurrent glioblastoma.

BACKGROUND: To determine the benefit of surgical management in recurrent glioblastoma, we analyzed a series of patients with recurrent glioblastoma who had undergone surgery, and we devised a new scale to predict their survival. METHODS: Clinical data from 55 consecutive patients with recurrent glioblastoma were evaluated after surgical management. Kaplan-Meier survival analysis and Cox proportional hazards regression modeling were used to identify prognostic variables for the development of a predictive scale. After the multivariate analysis, performance status (P = .078) and ependymal involvement (P = .025) were selected for inclusion in the new prognostic scale. The devised scale was validated with a separate set of 96 patients from 3 different institutes. RESULTS: A 3-tier scale (scoring range, 0-2 points) composed of additive scores for the Karnofsky performance status (KPS) (0 for KPS ≥ 70 and 1 for KPS < 70) and ependymal involvement (0 for no enhancement and 1 for enhancement of the ventricle wall in the magnetic resonance imaging) significantly distinguished groups with good (0 points; median survival, 18.0 months), intermediate (1 point; median survival, 10.0 months), and poor prognoses (2 points; median survival, 4.0 months). The new scale was successfully applied to the validation cohort of patients showing distinct prognosis among the groups (median survivals of 11.0, 9.0, and 4.0 months for the 0-, 1-, and 2-point groups, respectively). CONCLUSIONS: We developed a practical scale to facilitate deciding whether to proceed with surgical management in patients with recurrent glioblastoma. This scale was useful for the diagnosis of prognostic groups and can be used to develop guidelines for patient treatment.

Radiosurgery to palliate symptoms in brain metastases from uterine cervix cancer.

BACKGROUND: The optimal management of brain metastases from uterine cervix cancer (UCC) is not well defined because of the rarity of the condition and the scarcity of published reports. Here we report our experience with stereotactic radiosurgery for the management of brain metastases from UCC. METHODS: Thirteen consecutive patients with brain metastases from UCC were managed with a Leksell gamma-knife at our institution between January 2003 and December 2010. Clinical features and radiosurgical outcomes of patients were analyzed retrospectively. RESULTS: Gamma-knife radiosurgery (GKRS) was chosen as the only treatment in four patients and performed in combination with whole-brain radiotherapy (WBRT) in nine patients. GKRS was conducted simultaneously with WBRT within a 1-month interval in six patients and was chosen as the salvage treatment after WBRT in three patients. The mean number of metastatic brain lesions per patient was 5.7 (range, 1-16). The median cumulative tumor volume was 23.7 cm(3) (range, 2.7-40.2 cm(3)), and the median marginal dose covering the tumors was 14 Gy of a 50 % isodose line (range, 8-25 Gy). Nine patients showed relief of main neurologic symptoms after GKRS. The median length of time that the patients spent in an improved neurologic state was 11.1 weeks (range, 2-39.6 weeks). The local and distant control rates were 66.7 % and 77.8 %, respectively. The median survival from the date of GKRS until death was 4.6 months (range, 1.0-15.9 months). The 6-month and 12-month survival rates after GKRS were 38 and 15 %, respectively. CONCLUSIONS: GKRS could be an efficient palliative measure to relieve neurologic symptoms caused by brain metastasis from UCC.

Cerebellar liponeurocytoma with an unusually aggressive histopathology : case report and review of the literature.

We report a rare case of cerebellar liponeurocytoma with an unusually aggressive histopathology. A 49-year-old man presented with a four-month history of headache, vertigo, and progressive swaying gait. Magnetic resonance imaging showed a 3×3.5 cm sized relatively well-demarcated round mass lesion in the fourth ventricle, characterized by high signal intensity on T2-weighted images. Postcontrast images revealed strong enhancement of the solid portion and the cyst wall. The patient underwent suboccipital craniectomy and tumor removal. The pathologic diagnosis was cerebellar liponeurocytoma. Adjuvant radiotherapy was offered due to concerns related to the high proliferative index (Ki-67, 13.68%) of the tumor. At the last routine postoperative follow-up visit (12 months), the patient complained of no specific symptom and there was no evidence of tumor recurrence. However, long-term follow-up and the analysis of similar cases are necessary because of the low number of reports and the short follow-up of cases.

Implementation and outcomes of a critical pathway for lumbar laminectomy or microdiscectomy.

OBJECTIVE: The aim of this study is to implement a critical pathway (CP) for patients undergoing lumbar laminectomy or microdiscectomy and describe the results before and after the CP in terms of length of hospital stay and cost. METHODS: From March 2008 to February 2009, 61 patients underwent lumbar laminectomy or microdiscectomy due to stenosis or one- or two-level disc herniation in our department and were included in the prepathway group. After development and implementation of the CP in March 2009, 58 patients were applicable for the CP, and these were classified as the postpathway group. RESULTS: The CP, which established a 6-day hospital stay (5 bed-days), was fulfilled by 42 patients (72.4%) in the postpathway group. The mean length of stay was 5.4 days in the postpathway group compared to 6.9 days in the prepathway group, demonstrating a 20% reduction, which was a statistically significant difference (p≤0.000). There was a statistically significant reduction in charges for bed and nursing care (p=0.002). CONCLUSION: Implementation of a CP for lumbar laminectomy or microdiscectomy produced significant decreases in length of hospitalization and charges for bed and nursing care. We believe that this CP reduces the unnecessary use of hospital resources without increasing risk of adverse events.

Intraoperative visual evoked potential has no association with postoperative visual outcomes in transsphenoidal surgery.

OBJECTIVE: The aim of this study was to elucidate the relationship between changes in the intraoperative visual evoked potential (VEP) waveform and postoperative visual functional outcomes. METHODS: Between February 2009 and December 2010, we performed endoscopic endonasal transsphenoidal surgery for sellar or perisellar lesions in 65 consecutive patients with intraoperative VEP monitoring using scalp electrodes under total venous anesthesia. Among the 65 patients, 53 patients were followed-up with postoperative visual function evaluation. VEP waveforms measured at baseline were compared with those obtained toward the end of surgery and the association between changes in VEP waveforms and visual outcomes measured preoperatively and postoperatively were assessed. RESULT: Reproducible waveforms were obtained intraoperatively in 95 of 106 eyes (89.6%). Of the 95 eyes with reproducible VEP, 64 eyes had stable VEP during the surgery, 19 eyes showed VEP improvement, and 12 eyes had VEP deterioration. Of 64 eyes with a stable VEP, 42 showed no change in visual acuity postoperatively, 13 manifested improvement, and 9 worsened. Of 19 eyes with intraoperative VEP improvement, 13 exhibited no change, 4 improved, and 2 worsened postoperatively. Among 12 eyes with VEP deterioration, just 2 eyes showed visual worsening while the other 10 did not change or improved. Postoperative visual evaluation revealed no light perception in 2 eyes whose intraoperative VEP waveforms were stable throughout the surgery. CONCLUSIONS: Intraoperative monitoring of VEP with scalp electrodes under total venous anesthesia had a reproducibility of 89.6% during transsphenoidal surgery for sellar or perisellar lesions. However, the intraoperative VEP waveforms showed no association with postoperative visual outcomes.

3D T2-weighted turbo spin-echo MR sequence for identifying cerebrospinal fluid leak after endoscopic endonasal pituitary surgery.

BACKGROUND: This study aimed to assess the efficacy of MR images with 3D T2-weighted turbo spin-echo (3D T2-TSE) sequences for early identification of postoperative cerebrospinal fluid (CSF) leaks. METHODS: We analyzed the medical records and radiological reports for 72 consecutive patients who underwent an endoscopic endonasal approach for sellar and parasellar lesions between April 2009 and December 2010. Patients were 38 men and 34 women with a mean age of 46.4 years. All underwent MR scanning within 2 postoperative days, which included 3D T2-TSE sequences as well as a conventional T2-weighted (T2W) protocol. Sequence accuracy in predicting postoperative CSF leaks was assessed for sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: A postoperative CSF leak was confirmed in 6 of 72 patients (8.3 %). On immediate postoperative MR images, 39 patients were suspicious for CSF leaks on conventional T2W sequences, while 18 patients on 3D T2-TSE. The 3D T2-TSE imaging had superior specificity and PPV (50 % vs. 81.8 %, 15.4 % vs. 33.3 %), while there was no difference in sensitivity and NPV compared with conventional T2W sequences. CONCLUSION: Compared to the conventional T2W protocol, MR imaging with the 3D T2-TSE protocol provides differential images around the sellar area with improved specificity and PPV for the detection of postoperative CSF leaks.

Uncovertebral hypertrophy is a significant risk factor for the occurrence of heterotopic ossification after cervical disc replacement: survivorship analysis of Bryan disc for single-level cervical arthroplasty.

OBJECTIVES: The purpose of this study is to investigate the incidence of heterotopic ossification (HO) in the Bryan cervical arthroplasty group and to identify associations between preoperative factors and the development of HO. METHODS: We performed a retrospective review of clinical and radiological data on patients who underwent single-level cervical arthroplasty with Bryan prosthesis between January 2005 and September 2007. Patients were postoperatively followed-up at 1, 3, 6, 12 months and every year thereafter. The clinical assessment was conducted using Odom's criteria. The presence of HO was evaluated on the basis of X-ray at each time-point according to the McAfee classification. In this study, we focused on survivorship of Bryan prosthesis for single-level arthroplasty. The occurrence of ROM-affecting HO was defined as a functional failure and was used as an endpoint for determining survivorship. RESULTS: Through the analysis of 19 cases of Bryan disc arthroplasty for cervical radiculopathy and/or myelopathy, we revealed that ROM-affecting HO occurs in as many as 36.8% of cases and found that 37% of patients had ROM-affecting HO within 24 months following surgery. The overall survival time to the occurrence of ROM-affecting HO was 36.4 ± 4.4 months. Survival time of the prosthesis in the patient group without preoperative uncovertebral hypertrophy was significantly longer than that in the patient group with preoperative uncovertebral hypertrophy (47.2 months vs 25.5 months, p = 0.02). Cox regression proportional hazard analysis illustrated that preoperative uncovertebral hypertrophy was determined as a significant risk factor for the occurrence of ROM-affecting HO (hazard ratio = 12.30; 95% confidential interval = 1.10-137.03; p = 0.04). CONCLUSION: These findings suggest that the condition of the uncovertebral joint must be evaluated in preoperative planning for Bryan cervical arthroplasty.

Injectable hydroxyapatite cement patch as an on-lay graft for the sellar reconstructions following endoscopic endonasal approach.

BACKGROUND: Skull base reconstruction after endoscopic endonasal resection of a variety of skull base lesions remains challenging because of some lethal complications such as cerebrospinal fluid (CSF) leaks. We investigated the outcomes of hydroxyapatite (HA) cement patch as on-lay graft for skull base defects following endoscopic endonasal approach (EEA). METHODS: We analyzed 53 consecutive patients who underwent sellar reconstruction using HA cement following EEA at our institution between July 2009 and March 2011. Patients were composed of 23 men and 30 women with a mean age of 47 years, ranging from 10 to 72 years. Among these patients, 29 patients (54.7%) experienced intraoperative CSF leaks with high-output, 10 patients (18.9%) underwent CSF leaks with low output, and 14 patients (26.4%) experienced no intraoperative CSF leak. Mean follow-up period for clinical outcomes was 8.6 months (range, 3-22 months). RESULTS: We performed injectable HA patch as on-lay graft over fascia lata for the skull base defects. Routine lumbar CSF drainage was not performed postoperatively in any patients since the introduction of HA. During the follow-up period, three of 53 patients (5.6%) demonstrated meningitis associated with postoperative CSF leaks and underwent re-do reconstruction surgery. There was no allergic symptoms associated with HA cement. At an outpatient clinic, the defects were found to be covered with surrounding nasal mucosa at an average of 14 weeks (range, 3-28 weeks). CONCLUSIONS: The use of HA cement as an on-lay patch for the reconstruction of sellar defect demonstrated a low incidence of CSF leaks with minimal complications. HA cement may be an alternative option for repair of CSF leaks following EEA.

Significance of interfacet distance, facet joint orientation, and lumbar lordosis in spondylolysis.

The aim of this study is to reveal the association between lumbar spondylolysis and several radiologic parameters, which had been suggested to be significant. The authors examine interfacet distance (IFD), facet joint orientation (FJO), and lumbar segmental lordosis (LSL) all together on the basis of lumbar computed tomography (CT) scan of 35 patients with L5 spondylolysis and 36 unaffected control groups. Thirty-five Korean military recruits, aged 19-23 (mean 20.9 years), were diagnosed as L5 spondylolysis by lumber CT scans. As a control group, 36 male Korean military recruits, aged 18-25 (mean 21.3 years), were reconfirmed as not affected by lumbar spondylolysis by CT scan when they visited our hospital complaining of back pain. This study compares IFD, FJO, and LSL for each lumbar segment between the spondylolytic and unaffected groups. We also propose the use of normal mean data of IFD, FJO, and LSL of lumbar vertebrae from 36 Korean young military recruits because each measurement has power as an absolute value, like data from an osteologic collection in other studies. Comparison of IFD between spondylolytic and unaffected individuals reveals significant differences at the L3, L4, and L5 level (P = 0.0384, P = 0.0219, and P < 0.0001, respectively). In the group of spondylolysis, the increase of IFD from L4 to S1 was less pronounced (P < 0.0001) and the LSL at L5-S1 was more lordotic (P = 0.0203). Interfacet distance and lumbar lordosis were significantly different between patients with L5 spondylolysis and individuals without pars defect on L5. In the spondylolysis group, and the increase of IFD from L4 to S1 was less pronounced and the LSL at L5-S1 was more lordotic.

Dystrophic calcification in the epidural and extraforaminal space caused by repetitive triamcinolone acetonide injections.

The authors report a case of epidural and extraforaminal calcification caused by repetitive triamcinolone acetonide injections. A 66-year-old woman was admitted presenting with lower extremity weakness and radiating pain in her left leg. Ten months before admission, the patient was diagnosed as having an L4-5 spinal stenosis and underwent anterior lumbar interbody fusion followed by posterior fixation. Her symptoms had been sustained and she did not respond to transforaminal steroid injections. Repetitive injections (10 times) had been performed on the L4-5 level for six months. She had been taking bisphosphonate as an antiresorptive agent for ten months after surgery. Calcification in the ventral epidural and extraforaminal space was detected. The gritty particles were removed during decompressive surgery and these were proven to be a dystrophic calcification. The patient recovered from weakness and radiating leg pain. Repetitive triamcinolone acetonide injections after discectomy may be the cause of dystrophic calcification not only in the degenerated residual disc, but also in the posterior longitudinal ligament. Possible mechanisms may include the toxicity of preservatives and the insolubility of triamcinolone acetonide. We should consider that repetitive triamcinolone injections in the postdisectomy state may cause intraspinal ossification and calcification.

Incidence of deep vein thrombosis after spinal cord injury: a prospective study in 37 consecutive patients with traumatic or nontraumatic spinal cord injury treated by mechanical prophylaxis.

BACKGROUND: Patients with spinal cord injury (SCI) are at particular risk for deep vein thrombosis (DVT) during their hospital course. In most researches on the prevention of thromboembolic events after SCI, the cause of SCI was usually limited to traumatic origin, and pharmaco-prophylaxis was usually started immediately after SCI irrespective of the presence of DVT. For this reason, it is difficult to determine the exact incidence of DVT after SCI from all possible causes in the absence of anticoagulation treatment. We sought to determine the incidence of DVT and the effect of mechanical treatments without chemical prophylaxis. METHODS: From November 2009 to October 2010, 37 consecutive patients were admitted to our institute for SCI regardless of causes. Patient data including age, sex, types of injury in motor completeness, causes of SCI, and results of color Doppler ultrasonography (DUS) were collected. Routine mechanical prophylaxis for DVT was performed in all patients; pharmacologic prophylaxis was not used to avoid the potential consequences that may have confounded their benefits. All patients were routinely checked for DVT of lower limbs. Examinations were usually performed within 1 week of injury and repeated fortnightly until any medications for DVT were started in cases of a positive DUS result. RESULTS: In total, 16 of the 37 (43%) patients with acute SCI routinely given mechanical prophylaxis without anticoagulation were found to have DVT in the lower extremities by color DUS. Ten patients showed new thrombosis by DUS within 7 days after injury, three patients after 2 weeks to 3 weeks, and three patients at more than 1 month after injury. The majority of DVT occurred in the distal leg vein (81.2%, soleal vein). The incidence of DVT in patients with traumatic SCI was not different from that of patients with nontraumatic SCI in this study (p>0.05). Age, sex, type of motor impairment, and cause of SCI were not found to be significantly related to the occurrence of DVT. CONCLUSIONS: The incidence of DVT in patients with SCI routinely given mechanical prophylaxis without anticoagulation was higher when compared with those reported in the setting of routine pharmaco-prophylaxis. Anticoagulation should not be excluded from initial DVT prophylaxis measures in the SCI patients unless there is any ongoing bleeding or severe coagulopathy. Further studies will be necessary to get a more precise data and to understand the clinical relevance of these results.

Spinal intradural extramedullary cavernoma presenting with intracranial superficial hemosiderosis.

A case of intradural extramedullary cavernous angioma is presented with headache, dizziness, and bilateral sensorineural hearing loss caused by an intracranial superficial hemosiderosis. It was incidentally found in a patient with a 3-month history of sustained headache, dizziness and a 3-year history of hearing difficulty. The neurological examination was unremarkable in the lower extremity. MR images showed an intracranial superficial hemosiderosis mostly in the cerebellar region. Myelography and MR images of the thoracolumbar spine revealed an intradural extramedullary mass, which was pathologically proven to be a cavernous angioma. T12 total laminoplastic laminotomy and total tumor removal were performed without any neurologic deficits. The patient's symptoms, including headache and dizziness, have been absent for three years. Intradural extramedullary cavernous angioma can present with an intracranial superficial hemosiderosis as a result of chronic subarachnoid hemorrhage.

Microsurgical resection of deep-seated lesions using transparent tubular retractor: pediatric case series.

BACKGROUND: To facilitate effective resection of deep-seated brain lesions without causing significant trauma to the overlying cortex, the authors used a transparent plastic tubular retractor to approach these lesions. METHODS: Between July 2009 and January 2011, we used an 11-mm diameter transparent plastic tubular retractor in combination with a frameless stereotactic navigation system to remove 18 deep lesions. RESULTS: Gross total resection of the lesions was achieved in 14 of 18 patients, and subtotal removal occurred in four patients. Effective resection of lesions was achieved in all patients through small size craniotomy window and small cortical incision. The histopathologic diagnosis was established in all 18 patients: 3 hematomas, 3 cavernous angioma, 7 low-grade glioma, 2 dysembryoplastic neuroepithelial tumor, 1 choroid plexus papilloma, 1 abscess, and 1 meningioma. CONCLUSION: Microsurgery using a transparent tubular retractor guided by a neuronavigation system facilitated accurate and effective removal of these deep-seated brain lesions.