Soon Ki Sung

Comparative Study of Clinical and Radiological Outcomes of a Zero-Profile Device Concerning Reduced Postoperative Dysphagia after Single Level Anterior Cervical Discectomy and Fusion

Objective This study analyzed clinical and radiological outcomes of a zero-profile anchored spacer (Zero-P) and conventional cage-plate (CCP) for single level anterior cervical discectomy and fusion (ACDF) to compare the incidence and difference of postoperative dysphagia with both devices. Methods We retrospectively reviewed our experiences of single level ACDF with the CCP and Zero-P. From January 2011 to December 2013, 48 patients who had single level herniated intervertebral disc were operated on using ACDF, with CCP in 27 patients and Zero-P in 21 patients. Patients who received more than double-level ACDF or combined circumferential fusion were excluded. Age, operation time, estimated blood loss (EBL), pre-operative modified Japanese Orthopaedic Association (mJOA) scores, post-operative mJOA scores, achieved mJOA scores and recovery rate of mJOA scores were assessed. Prevertebral soft tissue thickness and postoperative dysphagia were analyzed on the day of surgery, and 2 weeks and 6 months postoperatively. Results The Zero-P group showed same or favorable clinical and radiological outcomes compared with the CCP group. Postoperative dysphagia was significantly low in the Zero-P group. Conclusions Application of Zero-P may achieve favorable outcomes and reduce postoperative dysphagia in single level ACDF.

Acute Spontaneous Subdural Hematoma of Arterial Origin

Acute spontaneous subdural hematoma (SDH) of arterial origin is very rare. We report a case of acute spontaneous SDH that showed contrast media extravasation from cortical artery on angiograms. A 58-year-old male patient developed sudden onset headache and right hemiparesis. Brain CT scan demonstrated acute SDH at left convexity. The patient was drowsy mentality on admission. He had no history of head trauma. Cerebral angiography was performed and revealed a localized extravasation of the contrast media from distal cortical MCA branch. After angiography, the patient deteriorated to comatose mentality. Decompressive craniectomy for removal of SDH was performed. We verified the arterial origin of the bleeding and coagulated the bleeding focus. The histological diagnosis was aneurysmal artery. He recovered after surgery with mild disability. In a case of acute spontaneous SDH, the possibility of a cortical artery origin should be considered.

Terson Syndrome Caused by Intraventricular Hemorrhage Associated with Moyamoya Disease

Terson syndrome was originally used to describe a vitreous hemorrhage arising from aneurysmal subrarachnoid hemorrhage. Terson syndrome can be caused by intracranial hemorrhage, subdural or epidural hematoma and severe brain injury but is extremely rare in intraventricular hemorrhage associated with moyamoya disease. A 41-year-old man presented with left visual disturbance. He had a history of intraventicular hemorrhage associated with moyamoya disease three months prior to admission. At that time he was in comatose mentality. Ophthalmologic examination at our hospital detected a vitreous hemorrhage in his left eye, with right eye remaining normal. Vitrectomy with epiretinal membrane removal was performed. After operation his left visual acuity was recovered. Careful ophthalmologic examination is mandatory in patients with hemorrhagic moyamoya disease.

Treatment of hydrocephalus associated with neurosarcoidosis by multiple shunt placement.

A 31-year-old man was admitted to our hospital due to hydrocephalus with neurosarcoidosis. Ventriculo-peritoneal shunting was performed in the right lateral ventricle with intravenous methylprednisolone. Subsequently, after 4 months, additional ventriculo-peritoneal shunting in the left lateral ventricle was performed due to the enlarged left lateral ventricle and slit-like right lateral ventricle. After 6 months, he was re-admitted due to upward gaze palsy, and magnetic resonance image showed an isolated fourth ventricle with both the inlet and outlet of fourth ventricle obstructed by recurrent neurosarcoidosis. Owing to the difficulty of using an endoscope, we performed neuronavigator-guided ventriculo-peritoneal shunting via the left lateral transcerebellar approach for the treatment of the isolated fourth ventricle with intravenous methyl prednisolone. The patient was discharged with improved neurological status.

The Variable Ellipsoid Modeling Technique as a Verification Method for the Treatment Planning System of Gamma Knife Radiosurgery

OBJECTIVE The secondary verification of Leksell Gamma Knife treatment planning system (LGP) (which is the primary verification system) is extremely important in order to minimize the risk of treatment errors. Although prior methods have been developed to verify maximum dose and treatment time, none have studied maximum dose coordinates and treatment volume. METHODS We simulated the skull shape as an ellipsoid with its center at the junction between the mammillary bodies and the brain stem. The radiation depths of the beamlets emitted from 201 collimators were calculated based on the relationship between this ellipsoid and a single beamlet expressed as a straight line. A computer program was coded to execute the algorithm. A database system was adopted to log the doses for 31x31x31 or 29,791 matrix points allowing for future queries to be made of the matrix of interest. RESULTS When we compared the parameters in seven patients, all parameters showed good correlation. The number of matrix points with a dose higher than 30% of the maximal dose was within +/- 2% of LGP. The 50% dose volume, which is generally the target volume, differs maximally by 4.2%. The difference of the maximal dose ranges from 0.7% to 7%. CONCLUSION Based on the results, the variable ellipsoid modeling technique or variable ellipsoid modeling technique (VEMT) can be a useful and independent tool to verify the important parameters of LGP and make up for LGP.

Migration of an Intracranial Subdural Hematoma to the Spinal Subdural Space: A Case Report.

A 57-year-old man complained of severe lower back pain and radicular pain in both legs for 1 week after falling from a ladder. Magnetic resonance imaging (MRI) of the spine showed a subdural hematoma (SDH), which was surgically removed. The patient had no back pain or the radicular leg pain at 2 weeks post-surgery. However, he complained of diffuse headaches upon follow-up. Brain computed tomography (CT) and MRI revealed an intracranial SDH, which was immediately removed by surgery. During his 1-year follow-up, he reported that the pain had resolved without recurrence. Simultaneous spinal and intracranial SDH are rare and no standard treatment exists for this condition. This case suggests that it is possible that an intracranial SDH can migrate into the cerebrospinal fluid (CSF) space through an arachnoid tear. CSF circulation allows the intracranial SDH to enter subarachnoid spaces encasing the spinal cord. In order to prevent irreversible damage, surgical intervention should be considered for case of spinal SDH with progressive neurological deficits.

Remote Hemorrhage after Burr Hole Drainage of Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) and symptomatic subdural hygroma are common diseases that require neurosurgical management. Burr hole trephination is the most popular surgical treatment for CSDH and subdural hygroma because of a low recurrence rate and low morbidity compared with craniotomy with membranectomy, and twist-drill craniotomy. Many reports suggest that placing a catheter in the subdural space for drainage can further reduce the rate of recurrence; however, complications associated with this type of drainage include acute subdural hematoma, cortical injury, and infection. Remote hemorrhage due to overdrainage of cerebrospinal fluid (CSF) is another possible complication of burr hole trephination with catheter drainage that has rarely been reported. Here, we present 2 cases of remote hemorrhages following burr hole trephination with catheter drainage for the treatment of CSDH and symptomatic subdural hygroma. One patient developed intracerebral hemorrhage and subarachnoid hemorrhage in the contralateral hemisphere, while another patient developed remote hemorrhage 3 days after the procedure due to the sudden drainage of a large amount of subdural fluid over a 24-hour period. These findings suggest that catheter drainage should be carefully monitored to avoid overdrainage of CSF after burr hole trephination.

A Lower T1 Slope as a Predictor of Subsidence in Anterior Cervical Discectomy and Fusion with Stand-Alone Cages

Objective Preoperative parameters including the T1 slope (T1S) and C2–C7 sagittal vertical axis (SVA) have been recognized as predictors of kyphosis after laminoplasty, which is accompanied by posterior neck muscle damage. The importance of preoperative parameters has been under-estimated in anterior cervical discectomy and fusion (ACDF) because there is no posterior neck muscle damage. We aimed to determine whether postoperative subsidence and pseudarthrosis could be predicted according to specific parameters on preoperative plain radiographs. Methods We retrospectively analyzed 41 consecutive patients (male: female, 22: 19; mean age, 51.15±9.25 years) who underwent ACDF with a stand-alone polyether-ether-ketone (PEEK) cage (>1 year follow-up). Parameters including SVA, T1S, segmental angle and range of motion (ROM), C2–C7 cervical angle and ROM, and segmental inter-spinous distance were measured on preoperative plain radiographs. Risk factors of subsidence and pseudarthrosis were determined using multivariate logistic regression. Results Fifty-five segments (27 single-segment and 14 two-segment fusions) were included. The subsidence and pseudarthrosis rates based on the number of segments were 36.4% and 29.1%, respectively. Demographic data and fusion level were unrelated to subsidence. A greater T1S was associated with a lower risk of subsidence (p=0.017, odds ratio=0.206). A cutoff value of T1S<28° significantly predicted subsidence (sensitivity: 70%, specificity: 68.6%). There were no preoperative predictors of pseudarthrosis except old age. Conclusion A lower T1S (T1S<28°) could be a risk factor of subsidence following ACDF. Surgeons need to be aware of this risk factor and should consider various supportive procedures to reduce the subsidence rates for such cases.

Differences in Cervical Sagittal Alignment Changes in Patients Undergoing Laminoplasty and Anterior Cervical Discectomy and Fusion

Objective Anterior cervical discectomy and fusion (ACDF) and laminoplasty (LP) are the most commonly performed procedures for degenerative cervical spondylosis. Cervical sagittal alignment (CSA) has recently been studied as an important predictor of clinical and radiological outcomes. The data from previous studies are insufficient for analysis using the recently designed CSA parameters, T1 slope (T1s), and T1s minus cervical angle (T1sCA). Methods We retrospectively collected data from patients who underwent ACDF and LP from January 2013 to May 2016. The CSA parameters included CA, sagittal vertical axis, T1s, and T1sCA. T1sCA values were used to evaluate the preoperative cervical balance (T1sCA>20°: imbalance). Clinical results were evaluated using the neck disability index (NDI) and recovery rate (RR) according to the Japanese Orthopedic Association scoring system. Results We analyzed the data of 72 patients (ACDF, n=39; LP, n=33). Imbalance on ACDF was associated with an increase in CA (balance: preoperative [PRE], 15.64° → follow-up [F/U], 15.74°, p=0.953; imbalance: PRE, −1.14° → F/U, 8.045°, p=0.008), whereas balance on LP was associated with a significant decrease in CA (balance: PRE, 16.26°→ F/U, 11.59°, p=0.009; imbalance: PRE, 5.36°→ F/U, 2.38°, p=0.249). No significant difference was found in the RR and NDI changes in the ACDF group based on balance, but a significant difference was found in RR in the LP group (balance: 61.65%±19.88%, imbalance: 46.90%±15.71%, p=0.046). Conclusion We found a significant difference in postoperative alignment in cases of ACDF and LP according to preoperative cervical sagittal balance. The postoperative clinical results of the LP group were more affected by F/U alignment than by the degree of alignment change.

Variation of C-Reactive Protein and White Blood Cell Counts in Spinal Operation: Primary Fusion Surgery Versus Revision Fusion Surgery

Objective Serum C-reactive protein (CRP) concentrations and white blood cell (WBC) count are commonly used to identify postoperative wound infections. We investigated whether changes in serum CRP levels and WBC counts actually differed between patients undergoing revision spinal fusion surgery and those undergoing a primary fusion. Methods Patients who underwent posterolateral fusion (PLF) surgery at Pusan National University Yangsan Hospital between October 2013 and April 2015 were considered for this study. Sixty-seven patients with primary lumbar PLF (pPLF) and 21 with revision PLF (rPLF) were enrolled. A retrospective assessment of preoperative and postoperative CRP levels and WBC count was undertaken. Also, we gathered peak CRP day, and CRP normalization days. Comorbidity data were also obtained to evaluate any effects on the course of CRP and WBC count postoperatively. Results CRP levels peaked at 3 days after surgery. The maximum CRP values recorded for each group: 4.17 (standard deviation [SD], 4.18) mg/dL and 4.88 (SD, 3.03) mg/dL for pPLF and rPLF. This difference was not statistically significant (p=0.24). A rapid fall in CRP within 5–9 days was observed for both groups. Conclusion Out of our expectation, changes in CRP levels after spinal fusion surgery follow the same course regardless of whether it is a revision operation or not. Because of this result, both the primary PLF surgery and revision PLF surgery should be monitored using CRP in the similar way and the antibiotic administration should be determined.