The Effect of Hounsfield Unit Value with Conventional Computed Tomography and Intraoperative Distraction on Postoperative Intervertebral Height Reduction in Patients Following Stand-Alone Anterior Cervical Discectomy and Fusion

Objective@#: The most common complication of anterior cervical discectomy and fusion (ACDF) is cage subsidence and maintenance of disc height affects postoperative clinical outcomes. We considered cage subsidence as an inappropriate indicator for evaluating preservation of disc height. Thus, this study aimed to consider patients with complications such as reduced total disc height compared to that before surgery and evaluate the relevance of several factors before ACDF. @*Methods@#: We retrospectively reviewed the medical records of 40 patients who underwent stand-alone single-level ACDF using a polyetheretherketone (PEEK) cage at our institution between January 2012 and December 2018. Our study population comprised 19 male and 21 female patients aged 24–70 years. The minimum follow-up period was 1 year. Twenty-seven patients had preoperative bone mineral density (BMD) data on dual-energy X-ray absorptiometry. Clinical parameters included sex, age, body mass index, smoking history, and prior medical history. Radiologic parameters included the C2-7 cobb angle, segmental angle, sagittal vertical axis, disc height, and total intervertebral height (TIH) at the preoperative and postoperative periods. Cage decrement was defined as the reduction in TIH at the 6-month follow-up compared to preoperative TIH. To evaluate the bone quality, Hounsfield unit (HU) value was calculated in the axial and sagittal images of conventional computed tomography. @*Results@#: Lumbar BMD values and cervical HU values were significantly correlated (r=0.733, p<0.001). We divided the patients into two groups based on cage decrement, and 47.5% of the total patients were regarded as cage decrement. There were statistically significant differences in the parameters of measuring the HU value of the vertebra and intraoperative distraction between the two groups. Using these identified factors, we performed a receiver operating characteristic (ROC) curve analysis. Based on the ROC curve, the cut-off point was 530 at the HU value of the upper cortical and cancellous vertebrae (p=0.014; area under the curve [AUC], 0.727; sensitivity, 94.7%; specificity, 42.9%) and 22.41 at intraoperative distraction (p=0.017; AUC, 0.722; sensitivity, 85.7%; specificity, 57.9%). Using this value, we converted these parameters into a bifurcated variable and assessed the multinomial regression analysis to evaluate the risk factors for cage decrement in ACDF. Intraoperative distraction and HU value of the upper vertebral body were independent factors of postoperative subsidence. @*Conclusion@#: Insufficient intraoperative distraction and low HU value showed a strong relationship with postoperative intervertebral height reduction following single stand-alone PEEK cage ACDF.

Surgical Treatment for Degenerative Lumbar Disease With Neurologic Deficits: Comparison Between Oblique Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion / 대한신경손상학회지

Objective@#This study aimed to compare the radiological and clinical outcomes of oblique lumbar interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF) surgeries and to confirm the effects of additional partial laminectomy on the surgical outcomes of OLIF. @*Methods@#This retrospective study included 130 patients who underwent OLIF or PLIF for single-level fusion. Among them, 42 patients underwent PLIF and open pedicle screw fixation and 88 underwent OLIF and percutaneous pedicle screw fixation. In the OLIF group, 42 patients received additional neural decompression through partial laminectomy and discectomy (direct OLIF), whereas the remaining 46 patients did not (indirect OLIF). To measure the neurological deficits, the clinical outcomes were evaluated using a visual analog scale for back and leg pain and the Oswestry Disability Index. Radiologic outcomes were evaluated based on the disc and foraminal heights as well as the segmental lordotic and lumbar lordotic angles. @*Results@#The improvement in the clinical outcomes did not differ significantly among the 3 groups. Radiologically, the 2 OLIF groups showed statistically significant improvements in the disc and foraminal heights when compared with the PLIF group. The PLIF group showed a significant decrease in the disc height and segmental lordotic angle when compared with the OLIF group in the postoperative 1-year period. @*Conclusion@#Both OLIF and PLIF showed similar clinical outcomes in the single-level lumbar fusion. However, OLIF grafts showed an advantage over PLIF with respect to the radiographic outcomes and complication rates. Additionally, partial laminectomy did not significantly affect the radiological results.

Does the COVID-19 Screening Test Affect the Postoperative Prognosis of Patients Who Undergo Emergency Surgery for Cerebral Hemorrhage? / 대한신경손상학회지

Objective@#The coronavirus disease 2019 (COVID-19) pandemic has affected all medical fields, including neurosurgery. Particularly, performing preoperative screening tests has become mandatory, potentially extending the time from admission to the emergency room and operating room, thus possibly affecting patients’ prognosis. This study aimed to determine the influence of COVID-19 screening time on patients’ postoperative prognosis. @*Methods@#From September 10, 2020, to May 31, 2021, we retrospectively evaluated 54 patients with cerebral hemorrhage who underwent emergency surgery in the emergency room after the screening test. The control group included 89 patients with cerebral hemorrhage who underwent emergency surgery between January 2019 and March 2020, i.e., the period before the COVID-19 pandemic. Prognosis was measured using the Glasgow Coma Scale scores, which were obtained preoperatively, postoperatively, and at discharge, and the modified Rankin Scale (mRS). Additionally, unfavorable outcomes (mRS score 3–6) and in-hospital mortality rates were investigated for postoperative prognostic assessments. @*Results@#No remarkable differences were observed in the time to surgical intervention and prognostic evaluation scores between patients with cerebral hemorrhage who underwent COVID-19 screening tests and subjects in the control group. @*Conclusion@#This study confirmed that patient treatment and prognosis were not significantly affected by additional preoperative screening testing times during the pandemic. We believe that our results are informative for the evaluation and performance of emergency neurosurgery during the pandemic.

Flow Diverter Devices for the Treatment of Unruptured Vertebral Artery Dissecting Aneurysm

Objective@#: Vertebral artery dissecting aneurysm (VADA) is a very rare subtype of intracranial aneurysms; when ruptured, it is associated with significantly high rates of morbidity and mortality. Despite several discussions and debates, the optimal treatment for VADA has not yet been established. In the last 10 years, flow diverter devices (FDD) have emerged as a challenging and new treatment method, and various clinical and radiological results have been reported about their safety and effectiveness. The aim of our study was to evaluate the clinical and radiological results with the use of FDD in the treatment of unruptured VADA. @*Methods@#: We retrospectively evaluated the data of all patients with unruptured VADA treated with FDD between January 2018 and February 2021 at our hybrid operating room. Nine patients with unruptured VADA, deemed hemodynamically unstable, were treated with FDD. Among other parameters, the technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcomes were evaluated. @*Results@#: Successful FDD deployment was achieved in all cases, and the immediate follow-up angiography showed intra-aneurysmal contrast stasis with parent artery preservation. A temporary episode of facial numbness and palsy was noted in one patient; however, the symptoms had completely disappeared when followed up at the outpatient clinic 2 weeks after the procedure. The 3–6 months follow-up angiography (n=9) demonstrated completeear-complete obliteration of the aneurysm in seven patients, and partial obliteration and segmental occlusion in one patient each. In the patient who achieved only partial obliteration, there was a sac 13 mm in size, and there was no change in the 1-year follow-up angiography. In the patient with segmental occlusion, the cause could not be determined. The clinical outcome was modified Rankin Scale 0 in all patients. @*Conclusion@#: Our preliminary study using FDD to treat hemodynamically unstable unruptured VADA showed that FDD is safe and effective. Our study has limitations in that the number of cases is small, and it is not a prospective study. However, we believe that the study contributes to evidence regarding the safety and effectiveness of FDD in the treatment of unruptured VADA.

Preoperative Radiological Parameters to Predict Clinical and Radiological Outcomes after Laminoplasty

Many studies have focused on pre-operative sagittal alignment parameters which could predict poor clinical or radiological outcomes after laminoplasty. However, the influx of too many new factors causes confusion. This study reviewed sagittal alignment parameters, predictive of clinical or radiological outcomes, in the literature. Preoperative kyphotic alignment was initially proposed as a predictor of clinical outcomes. The clinical significance of the K-line and K-line variants also has been studied. Sagittal vertical axis, T1 slope (T1s), T1s-cervical lordosis (CL), anterolisthesis, local kyphosis, the longitudinal distance index, and range of motion were proposed to have relationships with clinical outcomes. The relationship between loss of cervical lordosis (LCL) and T1s has been widely studied, but controversy remains. Extension function, the ratio of CL to T1s (CL/T1s), and Sharma classification were recently proposed as LCL predictors. In predicting postoperative kyphosis, T1s cannot predict postoperative kyphosis, but a low CL/T1s ratio was associated with postoperative kyphosis.

Learning Curve and Complications Experience of Oblique Lateral Interbody Fusion : A Single-Center 143 Consecutive Cases

Objective@#: Oblique lateral interbody fusion (OLIF) is becoming the preferred treatment for degenerative lumbar diseases. As beginners, we performed 143 surgeries over 19 months. In these consecutive cases, we analyzed the learning curve and reviewed the complications in our experience. @*Methods@#: This was a retrospective study; however, complications that were well known in the previous literature were strictly recorded prospectively. We followed up the changes in estimated blood loss (EBL), operation time, and transient psoas paresis according to case accumulation to analyze the learning curve. @*Results@#: Complication-free patients accounted for 43.6% (12.9%, early stage 70 patients and 74.3%, late stage 70 patients). The most common complication was transient psoas paresis (n=52). Most of these complications occurred in the early stages of learning. C-reactive protein normalization was delayed in seven patients (4.89%). The operation time showed a decreasing trend with the cases; however, EBL did not show any significant change. Notable operation-induced complications were cage malposition, vertebral body fracture, injury to the ureter, and injury to the lumbar vein. @*Conclusion@#: According to the learning curve, the operation time and psoas paresis decreased. It is important to select an appropriately sized cage along with clear dissection of the anterior border of the psoas muscle to prevent OLIF-specific complications.

A case of an unruptured duplicated middle cerebral artery aneurysm–An unusual presentation of the distal internal carotid artery aneurysm

The duplicated middle cerebral artery (DMCA) is an anatomic variation that arises from the distal internal carotid artery (ICA) and supplies blood to the middle cerebral artery (MCA) territory. Aneurysms of the DMCA have been reported in 36 cases in 2020. We also report a case of a 3.7 mm saccular aneurysm originating from the DMCA. A 52-year-old woman visited our hospital with worsening headache. She had no neurological abnormalities. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) revealed a right distal ICA aneurysm at the anterior choroidal artery. Cerebral angiography was performed to confirm the shape and the size of the aneurysm. Cerebral angiography revealed that the vessel that was originally identified as the anterior choroidal artery by the MRA was actually the duplicated MCA that was originating from the aneurysm neck and was supplying the MCA territory. The patient’s aneurysm was clipped using a transsylvian approach and she recovered without any neurological symptoms. DMCAs are rare and often associated with aneurysms and require preoperative evaluation to confirm the vascular status, aneurysm characteristics, and the shape of the parent artery.

Preoperative Radiological Parameters to Predict Clinical and Radiological Outcomes after Laminoplasty

Many studies have focused on pre-operative sagittal alignment parameters which could predict poor clinical or radiological outcomes after laminoplasty. However, the influx of too many new factors causes confusion. This study reviewed sagittal alignment parameters, predictive of clinical or radiological outcomes, in the literature. Preoperative kyphotic alignment was initially proposed as a predictor of clinical outcomes. The clinical significance of the K-line and K-line variants also has been studied. Sagittal vertical axis, T1 slope (T1s), T1s-cervical lordosis (CL), anterolisthesis, local kyphosis, the longitudinal distance index, and range of motion were proposed to have relationships with clinical outcomes. The relationship between loss of cervical lordosis (LCL) and T1s has been widely studied, but controversy remains. Extension function, the ratio of CL to T1s (CL/T1s), and Sharma classification were recently proposed as LCL predictors. In predicting postoperative kyphosis, T1s cannot predict postoperative kyphosis, but a low CL/T1s ratio was associated with postoperative kyphosis.

Learning Curve and Complications Experience of Oblique Lateral Interbody Fusion : A Single-Center 143 Consecutive Cases

Objective@#: Oblique lateral interbody fusion (OLIF) is becoming the preferred treatment for degenerative lumbar diseases. As beginners, we performed 143 surgeries over 19 months. In these consecutive cases, we analyzed the learning curve and reviewed the complications in our experience. @*Methods@#: This was a retrospective study; however, complications that were well known in the previous literature were strictly recorded prospectively. We followed up the changes in estimated blood loss (EBL), operation time, and transient psoas paresis according to case accumulation to analyze the learning curve. @*Results@#: Complication-free patients accounted for 43.6% (12.9%, early stage 70 patients and 74.3%, late stage 70 patients). The most common complication was transient psoas paresis (n=52). Most of these complications occurred in the early stages of learning. C-reactive protein normalization was delayed in seven patients (4.89%). The operation time showed a decreasing trend with the cases; however, EBL did not show any significant change. Notable operation-induced complications were cage malposition, vertebral body fracture, injury to the ureter, and injury to the lumbar vein. @*Conclusion@#: According to the learning curve, the operation time and psoas paresis decreased. It is important to select an appropriately sized cage along with clear dissection of the anterior border of the psoas muscle to prevent OLIF-specific complications.

A case of an unruptured duplicated middle cerebral artery aneurysm–An unusual presentation of the distal internal carotid artery aneurysm

The duplicated middle cerebral artery (DMCA) is an anatomic variation that arises from the distal internal carotid artery (ICA) and supplies blood to the middle cerebral artery (MCA) territory. Aneurysms of the DMCA have been reported in 36 cases in 2020. We also report a case of a 3.7 mm saccular aneurysm originating from the DMCA. A 52-year-old woman visited our hospital with worsening headache. She had no neurological abnormalities. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) revealed a right distal ICA aneurysm at the anterior choroidal artery. Cerebral angiography was performed to confirm the shape and the size of the aneurysm. Cerebral angiography revealed that the vessel that was originally identified as the anterior choroidal artery by the MRA was actually the duplicated MCA that was originating from the aneurysm neck and was supplying the MCA territory. The patient’s aneurysm was clipped using a transsylvian approach and she recovered without any neurological symptoms. DMCAs are rare and often associated with aneurysms and require preoperative evaluation to confirm the vascular status, aneurysm characteristics, and the shape of the parent artery.

Validation of Gamma Knife Perfexion Dose Profile Distribution by a Modified Variable Ellipsoid Modeling Technique

Objective@#: High precision and accuracy are expected in gamma knife radiosurgery treatment. Because of the requirement of clinically applying complex radiation and dose gradients together with a rapid radiation decline, a dedicated quality assurance program is required to maintain the radiation dosimetry and geometric accuracy and to reduce all associated risk factors. This study investigates the validity of Leksell Gamma plan (LGP)10.1.1 system of 5th generation Gamma Knife Perfexion as modified variable ellipsoid modeling technique (VEMT) method. @*Methods@#: To verify LGP10.1.1 system, we compare the treatment plan program system of the Gamma Knife Perfexion, that is, the LGP, with the calculated value of the proposed modified VEMT program. To verify a modified VEMT method, we compare the distributions of the dose of Gamma Knife Perfexion measured by Gafchromic EBT3 and EBT-XD films. For verification, the center of an 80 mm radius solid water phantom is placed in the center of all sectors positioned at 16 mm, 4 mm and 8 mm; that is, the dose distribution is similar to the method used in the x, y, and z directions by the VEMT. The dose distribution in the axial direction is compared and analyzed based on Full-Width-of-Half-Maximum (FWHM) evaluation. @*Results@#: The dose profile distribution was evaluated by FWHM, and it showed an average difference of 0.104 mm for the LGP value and 0.130 mm for the EBT-XD film. @*Conclusion@#: The modified VEMT yielded consistent results in the two processes. The use of the modified VEMT as a verification tool can enable the system to stably test and operate the Gamma Knife Perfexion treatment planning system.

Comparative Analysis of Surgical Outcomes of C1–2 Fusion Spine Surgery between Intraoperative Computed Tomography Image Based Navigation-Guided Operation and Fluoroscopy-Guided Operation

Objective@#: Fixation of the C1–2 segment is challenging because of the complex anatomy in the region and the need for a high degree of accuracy to avoid complications. Preoperative 3D-computed tomography (CT) scans can help reduce the risk of complications in the vertebral artery, spinal cord, and nerve roots. However, the patient may be susceptible to injury if the patient’s anatomy does not match the preoperative CT scans. The intraoperative 3D image-based navigation systems have reduced complications in instrument-assisted techniques due to greater accuracy. This study aimed to compare the radiologic outcomes of C1–2 fusion surgery between intraoperative CT image-guided operation and fluoroscopy-guided operation. @*Methods@#: We retrospectively reviewed the radiologic images of 34 patients who underwent C1–2 fusion spine surgery from January 2009 to November 2018 at our hospital. We assessed 17 cases each of degenerative cervical disease and trauma in a study population of 18 males and 16 females. The mean age was 54.8 years. A total of 139 screws were used and the surgical procedures included 68 screws in the C1 lateral mass, 58 screws in C2 pedicle, nine screws in C2 lamina and C2 pars screws, four lateral mass screws in sub-axial level. Of the 34 patients, 19 patients underwent screw insertion using intraoperative mobile CT. Other patients underwent atlantoaxial fusion with a standard fluoroscopy-guided device. @*Results@#: A total of 139 screws were correctly positioned. We analyzed the positions of 135 screws except for the four screws that performed the lateral mass screws in C3 vertebra. Minor screw penetration was observed in seven cases (5.2%), and major pedicle screw penetration was observed in three cases (2.2%). In one case, the malposition of a C2 pedicle screw was confirmed, which was subsequently corrected. There were no complications regarding vertebral artery injury or onset of new neurologic deficits. The screw malposition rate was lower (5.3%) in patients who underwent intraoperative CT-based navigation than that for fluoroscopy-guided cases (10.2%). And we confirmed that the operation time can be significantly reduced by surgery using intraoperative O-arm device. @*Conclusion@#: Spinal navigation using intraoperative cone-beam CT scans is reliable for posterior fixation in unstable C1-2 pathologies and can be reduced the operative time.

Current Status of Neurosurgical and Neurointensive Care Units in Korea : A Brief Report on Nationwide Survey Results

Objective@#: The purpose of this study is identify the operation status of the neurosurgical care units (NCUs) in neurosurgical residency training hospitals nationwide and determine needed changes by comparing findings with those obtained from the Korean Neurosurgical Society (KNS) and Korean Society of Neurointensive Care Medicine (KNIC) survey of 2010.Method : This survey was conducted over 1 year in 86 neurosurgical residency training hospitals and two neurosurgery specialist hospitals and focused on the following areas : 1) the current status of the infrastructure and operating systems of NCUs in Korea, 2) barriers to installing neurointensivist team systems, 3) future roles of the KNS and KNIC, and 4) a handbook for physicians and practitioners in NCUs. We compared and analyzed the results of this survey with those from a KNIC survey of 2010. @*Results@#: Seventy seven hospitals (87.5%) participated in the survey. Nineteen hospitals (24.7%) employed a neurointensivist or faculty member; Thirty seven hospitals (48.1%) reported high demand for neurointensivists, and 62 hospitals (80.5%) stated that the mandatory deployment of a neurointensivist improved the quality of patient care. Forty four hospitals (57.1%) believed that hiring neurointensivist would increase hospital costs, and in response to a question on potential earnings declines. In terms of potential solutions to these problems, 70 respondents (90.9%) maintained that additional fees were necessary for neurointensivists’ work, and 64 (83.1%) answered that direct support was needed of the personnel expenses for neurointensivists. @*Conclusion@#: We hope the results of this survey will guide successful implementation of neurointensivist systems across Korea.

Clinical Safety and Effectiveness of Stent-Assisted Coil Embolization with Neuroform Atlas Stent in Intracranial Aneurysm

Objective@#: Stent-assisted coil embolization (SAC) is commonly used for treating wide-neck intracranial aneurysms. In this study, we aimed to assess the clinical safety and efficacy of the NeuroForm Atlas Stent during SAC of intracranial aneurysms. @*Methods@#: We retrospectively analyzed data from patients with ruptured and unruptured cerebral aneurysms, who underwent SAC using the NeuroForm Atlas between February 2018 and July 2018. Favorable clinical outcomes and degree of aneurysm occlusion were defined as a modified Rankin scale score of ≤2 and a Raymond-Roy occlusion classification (RROC) class I/II during the immediate postoperative period and at the 6-month follow-up, respectively. @*Results@#: Thirty-one consecutive patients with 33 cases, including 11 ruptured and 22 unruptured cases were treated via NeuroForm Atlas SAC. Among the 22 unruptured cases with 24 unruptured aneurysms had favorable clinical outcome. Complete occlusion (RROC I) was achieved in 16 aneurysms (66.7%), while neck remnants (RROC II) were observed in six aneurysms (25%). Among the 11 patients with ruptured aneurysms, two died due to re-bleeding and diabetic ketoacidosis. In ruptured cases, RROC I was observed in eight (72.7%) and RROC II was observed in three cases (27.3%). At the 6-month follow-up, no clinical events were observed in the 22 unruptured cases. In the ruptured nine cases, five patients recovered without neurologic deficits, while four experienced unfavorable outcomes at 6 months. Of the 29 aneurysms examined via angiography at the 6-month follow-up, 19 (65.5%) were RROC I, eight (27.6%) were RROC II and two (6.9%) were RROC III. There were no procedure-related hemorrhagic complications. @*Conclusion@#: In this study, we found that stent-assisted coil embolization with NeuroForm Atlas stent may be safe and effective in the treatment of wide-neck intracranial aneurysms. NeuroForm Atlas SAC is feasible for the treatment of both ruptured and unruptured wide-neck aneurysms.

Does Systemic Lupus Erythematosus Increase the Riskof Procedure-Related Complication in EndovascularTreatment of Intracranial Aneurysm?

Cerebral aneurysms associated with systemic lupus erythematosus (SLE) are more likely to grow rapidly and rupture, comparedto those found in the general population. The main underlying pathology of intracranial aneurysm and its rupture is presumed tobe SLE-related intracranial vasculitis and fragility of blood vessels due to prolonged use of steroid. For these reasons, both surgicaland endovascular options are challenging. On the other hand, given the possibility that SLE may predispose to growth andrupture of intracranial aneurysm, early intervention for cerebral aneurysms associated with SLE may be more necessary andbeneficial than other cerebral aneurysms in the general population. Here we would like to report on the unexpected complicationsthat occurred during or after endovascular treatment of an SLE patient with multiple aneurysms. The complications includeintraprocedural rupture of unruptured aneurysm, coil stretching, contrast-induced encephalopathy, and delayed ipsilateral intraparenchymalhemorrhage after stent-assisted coiling. Our unique case highlights that the SLE patient with multiple intracranialaneurysms had a higher risk of endovascular procedure-related complications, which might be due to the increased bleedingtendency and fragility of blood vessels.

Can Supine Magnetic Resonance Imaging Be an Alternative to Standing Lateral Radiographs for Evaluating Cervical Sagittal Alignment? / 대한신경손상학회지

Objective@#Recently, many studies have reported that cervical alignment is related to clinical outcomes. However, poor visibility of anatomical structures during X-ray (XR) imaging limits accurate measurements. In supine magnetic resonance (MR) imaging, the boundary of the anatomical structure is clear, but the correlation to XR images taken in a standing position is problematic. In this study, we evaluated the agreement of sagittal alignment parameters between MR and XR measurements. @*Methods@#We retrospectively reviewed 268 patients. Cervical sagittal parameters were measured using XR and MR images, and their relationships were evaluated using Pearson's correlation, paired t-tests, and 2-way random, single score intraclass correlation coefficient (ICCs) (2,1). Using simple linear regression analysis, MR results were converted to the expected value (MR-E). The subsequent comparison of MR-Es with XRs was used to examine whether MR-Es could replace XRs when the measurement difference was less than 2 mm or 2°. @*Results@#The correlation between the MR and XR measurements was high, but ICCs showed low reliability. All parameters were significantly different between XR and MR measurements in paired t-tests. Converting the MR values eliminated the t-test differences between MR-Es and XRs, but did not affect correlations and ICCs. The replacement ratio included the Cobb angle: 20.3%, T1: 27.1%, the sagittal vertical axis: 17.6%, C1–2: 29.7%, and C2: 16.0%. @*Conclusion@#These results indicate that supine MR measurements could not replace upright XR measurements.

Case Series of Ventriculoatrial Shunt placement in Hybrid Room: Reassessment of Ventriculoatrial Shunt / 대한신경손상학회지

Objective@#Ventriculoatrial shunt (VAS) remains an alternate option for treatment of hydrocephalus in patients with ventriculoperitoneal shunt (VPS) failure. Unfamiliar anatomy for a neurosurgeon has resulted in the VAS falling out of favor as a treatment option. However, there are unsatisfactory reports on the long-term result of VPS, and VAS has been recently re-evaluated. We are to report the simple way to do the VAS using a peel-away sheath in a hybrid operation room. @*Methods@#A jugular vein path was drawn by ultrasound, a small incision was made above the clavicle, and a shunt catheter was tunneled into it. The jugular vein was punctured beside the tunneled catheter with a Seldinger needle under ultrasound guidance. A flexible guide wire was introduced into the vein and 6-Fr peel-away sheath was advanced into the vein along the wire. Under fluoroscopic guidance, the catheter was cut to position approximately midlevel in the atrium. After the guide wire was removed, the distal shunt catheter was passed down. After confirming proper position of the distal catheter under the fluoroscope, the catheter-guiding sheath was pulled out as a peeling-away manner. We performed this surgical procedures in 5 cases. @*Results@#All the procedures of the VAS using a peel-away sheath were performed in a hybrid operation room Of 5 patients, 3 patients had the distal catheter failures in the peritoneal cavity and 2 patients had shunt A distal catheter was successfully indwelling in all the cases without any difficulties. After the surgery, neither shunt infection nor thromboembolic event happened. @*Conclusion@#VAS using fluoroscopy and a peel-away sheath is a good alternative option for hydrocephalus patients with shunt failure related to peritoneal cavity complications.

The experience of surgery and endovascular procedure of cerebrovascular disease in the hybrid operating room; Multi-axis robotic C-arm DSA system

Objective@#To report on combined surgical and/or endovascular procedures for cerebrovascular disease in a hybrid operating room (OR). @*Methods@#Between October 2016 and June 2020, 1832 neurosurgical procedures were performed in a hybrid OR. Our institution’s hybrid OR consists of a multi-axis robotic C-arm monoplane digital subtraction angiography (DSA) system with an operating table, 3D-rotational DSA, cone-beam computed tomography (dyna CT), and real-time navigation software. Procedures were categorized into six categories according to purpose: (1) simple diagnosis and follow-up, (2) simple endovascular procedure, (3) combination of surgery and endovascular procedures, (4) rescue surgery after endovascular procedures, (5) frameless stereotactic procedure, and (6) other surgeries requiring C-arm. @*Results@#Of 1832 neurosurgical procedures in the hybrid OR, 1430 were simple diagnosis and follow-up cases, 330 simple endovascular procedures, 8 combination of surgery and endovascular procedures, 15 rescue after endovascular procedure, 40 frameless stereotactic procedures, and 9 other surgeries. Eight cases of combination of surgery and endovascular procedures, safely performed without wasting time on patient transfer, were performed in seven bypass end endovascular procedures and one case of bow-hunter syndrome in complex cerebrovascular disease. After embolization, craniotomy (or craniectomy) and intracerebral hemorrhage removal were performed in eight patients in-situ. Of the 40 frameless stereotactic procedure, 37 were extraventricular drainage before/after coil embolization in subarachnoid hemorrhage patients. They all mounted conduits in their planned locations. @*Conclusions@#A hybrid OR for combined endovascular and surgical procedures represents a safe and useful strategy for cerebrovascular disease. In hybrid ORs various neurosurgical procedures can be safely and conveniently performed. Hybrid OR will pioneer a new era in neurosurgical procedures.

The experience of surgery and endovascular procedure of cerebrovascular disease in the hybrid operating room; Multi-axis robotic C-arm DSA system

Objective@#To report on combined surgical and/or endovascular procedures for cerebrovascular disease in a hybrid operating room (OR). @*Methods@#Between October 2016 and June 2020, 1832 neurosurgical procedures were performed in a hybrid OR. Our institution’s hybrid OR consists of a multi-axis robotic C-arm monoplane digital subtraction angiography (DSA) system with an operating table, 3D-rotational DSA, cone-beam computed tomography (dyna CT), and real-time navigation software. Procedures were categorized into six categories according to purpose: (1) simple diagnosis and follow-up, (2) simple endovascular procedure, (3) combination of surgery and endovascular procedures, (4) rescue surgery after endovascular procedures, (5) frameless stereotactic procedure, and (6) other surgeries requiring C-arm. @*Results@#Of 1832 neurosurgical procedures in the hybrid OR, 1430 were simple diagnosis and follow-up cases, 330 simple endovascular procedures, 8 combination of surgery and endovascular procedures, 15 rescue after endovascular procedure, 40 frameless stereotactic procedures, and 9 other surgeries. Eight cases of combination of surgery and endovascular procedures, safely performed without wasting time on patient transfer, were performed in seven bypass end endovascular procedures and one case of bow-hunter syndrome in complex cerebrovascular disease. After embolization, craniotomy (or craniectomy) and intracerebral hemorrhage removal were performed in eight patients in-situ. Of the 40 frameless stereotactic procedure, 37 were extraventricular drainage before/after coil embolization in subarachnoid hemorrhage patients. They all mounted conduits in their planned locations. @*Conclusions@#A hybrid OR for combined endovascular and surgical procedures represents a safe and useful strategy for cerebrovascular disease. In hybrid ORs various neurosurgical procedures can be safely and conveniently performed. Hybrid OR will pioneer a new era in neurosurgical procedures.

Risk Factors of Allogenous Bone Graft Collapse in Two-Level Anterior Cervical Discectomy and Fusion

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. METHODS: We retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. RESULTS: The subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ≥37.3% was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, 5.8±5.7 months; subsidence, 0.99±0.50 months; and instrument failure, 9.13±0.50 months. CONCLUSION: We experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various pre-operative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.