Shunt-dependent hydrocephalus and shunt failure rate in patients with aneurysmal subarachnoid hemorrhage in Korea.

OBJECTIVE: Shunt-dependent hydrocephalus is a major complication of aneurysmal subarachnoid hemorrhage (SAH). Despite this, the factors influencing shunt dependency and shunt failure remain unclear. Therefore, the aim of this study was to estimate shunt dependency and failure rates and determine the contributing factors in patients with aneurysmal SAH using the Korean National Health Insurance database over a 13-year period. METHODS: Patients with aneurysmal SAH aged > 18 years who underwent surgical procedures were included. Using the shunt surgery prescription data, the shunt-dependent hydrocephalus rate was evaluated according to sex, age, aneurysm location, and year of admission. Among patients who underwent shunt surgery, the shunt failure rate was estimated using surgical prescription data. RESULTS: A total of 57,030 patients with SAH who underwent aneurysm surgery were included. The overall raw rate of shunt-dependent hydrocephalus was 15.0% (8530/57,030). Age (HR 1.04, 95% CI 1.04-1.04; p < 0.001) and endovascular coiling (vs surgical clipping, HR 0.71, 95% CI 0.67-0.74; p < 0.001) were related to shunt-dependent hydrocephalus in the multivariate logistic regression analysis. Posterior circulation and anterior communicating aneurysms showed a high risk of shunt dependency. Among 8530 patients who underwent shunt surgery, the shunt failure rate was 11.3% (961/8530). Female sex (HR 1.18, 95% CI 1.01-1.39; p = 0.0324), age (HR 0.99, 95% CI 0.98-0.99; p < 0.001), early shunt placement (HR 1.25, 95% CI 1.08-1.47; p = 0.004) and lumboperitoneal shunt placement (HR 2.19, 95% CI 1.65-2.91; p < 0.001) were the risk factors for shunt failure in the multivariate logistic regression analysis. CONCLUSIONS: The rate of shunt-dependent hydrocephalus after aneurysmal SAH was 15.0% in this study using a medical claims database in Korea. The shunt surgery rate was highest in patients in their 60s and 70s. Shunt failure occurred in 11.3% of the patients, and a lumboperitoneal shunt was most related to the need for revision surgery.

Real-World Impact of Modern Reperfusion Therapy for Acute Ischemic Stroke : A Nationwide Population-Based Data Study in Korea.

OBJECTIVE: The treatment paradigm for acute ischemic stroke has undergone several major changes in the past decade, contributing to improved patient prognosis in clinical practice. However, the extent to which these changes have affected patient prognosis in the real-world is yet to be clarified. This study aimed to evaluate the real-world impact of modern reperfusion therapy for acute ischemic stroke using data from the National Health Insurance Service in Korea. METHODS: This study included patients aged 18-80 years who were admitted via the emergency room with an I63 code between 2011 and 2020. The rates of intravenous thrombolysis use and endovascular treatment according to the year of admission were investigated. Furthermore, the rates of decompressive craniectomy and 3-month mortality were also analyzed. The 10-year observational period was divided into three periods based on the 2015 guideline change as follows : prior, 2011-2014; transitional, 2015-2016; and modern, 2017-2020. RESULTS: A total of 307117 patients (mean age, 65.7±10.9 years) were included, and most patients were male (59.7%). The rate of endovascular treatment gradually increased during the study period from 0.71% in the prior period to 1.32% in the transitional period and finally to 1.85% in the modern period. Meanwhile, the 3-month mortality rate gradually decreased from 4.78% in the prior period to 4.03% in the transitional period and to 3.71% in the modern period. CONCLUSION: In Korea, the mortality rate decreased as the rate of modern reperfusion therapy increased in patients with acute ischemic stroke. Overall, technical and scientific advances in reperfusion therapy have improved the outcome of patients with acute ischemic stroke in Korea.

Aneurysmectomy and graft interposition for giant thrombosed proximal internal carotid artery aneurysm: Technical details.

A giant thrombosed extracranial internal carotid artery aneurysm (ECCA) is extremely rare and its treatment is challenging. Despite the advance of endovascular technique, open surgery is still considered a first-line treatment in giant thrombosed ECCA. We describe a case of giant thrombosed ECCA which was successfully treated by aneurysmectomy and graft interposition with the technical details.

Development of a Pedicle Screw Fixation Simulation Model for Surgical Training Using a 3-Dimensional Printer.

OBJECTIVE: Training surgeons in pedicle screw fixation (PSF) techniques during actual surgery is limited because of patient safety, complications, and surgical efficiency issues. Recent technical developments are leading the world to an era of personalized three-dimensional (3D) printing. This study aimed to evaluate the educational effect of using a 3D-printed spine model to train beginners in PSF techniques to improve screw accuracy and procedure time. METHODS: Computed tomography (CT) scan data were used in a 3D printer to produce a life-size lumbar spine replica of L1-3 vertebrae. Four residents performed PSF thrice. Each resident performed 18 screw fixations on both sides (6 screws per trial). The time to complete the procedure and pedicle violation was recorded. RESULTS: The average time for the 3 procedures was 42.1±2.9 minutes, 38.8±3.3 minutes, and 32.1±2.5 minutes, respectively. Furthermore, the average pedicle screw score for the 3 procedures was 13.0±0.8, 14.5±0.6, and 16.0±0.8, respectively. As the trial was repeated, the procedure time decreased and the accuracy of screw fixation tended to be more accurate. CONCLUSIONS: It was possible to decrease the procedure time and increase accuracy through repeated training using the 3D-printed spine model. By implementing a 3Dprinted spine model based on the patient's actual CT data, surgeons can perform simulation surgery before the actual surgery. Therefore, this technology can be useful in educating residents to improve their surgical skills.

The serpentine pattern on MRI as an early prognostic factor after fusion for lumbar spinal stenosis.

This study aimed to determine the relationship between the serpentine pattern nerve roots (SNR) and prognosis after lumbar fusion for lumbar spinal stenosis (LSS) by comparing clinical outcomes in patients with or without a serpentine pattern. LSS patients with neurological symptoms often present with SNRs. Several studies have shown that LLS symptoms are worse in patients with SNRs. However, the relationship between SNR and outcome after spinal fusion surgery has not yet been established. A total of 332 patients who underwent spinal fusion surgery between January 1, 2010, and December 31, 2019, were enrolled. Patients were divided into those with a serpentine pattern (S group) and those without a serpentine pattern (N group). The prognosis of the 2 groups was compared using visual analog scale (VAS), Oswestry disability index, claudication distance, medication dose for leg dysesthesia, and glucose tolerance. A total of 113 patients had a serpentine pattern, while the remaining 219 did not. Symptom duration and presence of diabetes mellitus were significantly different between the 2 groups (N = 25.4, S = 32.6, P < .05). Changes in the VAS score for lower extremity pain between the 2 groups at 1 year after surgery showed that patients without a serpentine pattern had significantly better outcomes than those with a serpentine pattern (N: 2.7 ±â€…1.1 vs S: 4.1 ±â€…1.3; P < .001), despite the score change at 1 month showing no difference (N: 3.5 ±â€…0.9 vs S: 3.8 ±â€…1.0; P = .09). SNRs on MRI are more prevalent in diabetic patients and are a negative prognostic factor in lumbar fusion surgery for LSS. Our insights may help physicians decide the optimal surgical plan and predict the postoperative prognosis of patients with LSS.

Difference in the Cobb Angle Between Standing and Supine Position as a Prognostic Factor After Vertebral Augmentation in Osteoporotic Vertebral Compression Fractures.

OBJECTIVE: We retrospectively analyzed patients with osteoporotic vertebral compression fracture (OVCF) undergoing vertebral augmentation to compare the Cobb angle changes in the supine and standing positions and the clinical outcomes. METHODS: We retrospectively extracted the data of OVCF patients who underwent vertebral augmentation. Back pain was assessed using a visual analogue scale (VAS). Supine and standing radiographs were assessed before treatment to determine the Cobb angle and compression ratio. Receiver operating characteristic curve analysis was performed to determine the optimal cutoff to predict favorable outcomes after vertebral augmentation. RESULTS: A total of 249 patients were included. We observed a statistically significant increase in the VAS score change with increasing Cobb angle and compression ratio (p < 0.001), and multivariate logistic regression analysis showed that a difference in the Cobb angle (odds ratio [OR], 1.27) and compression ratio (OR, 1.12) were the independent risk factors for predicting short-term favorable outcomes after vertebral augmentation. In addition, we found that the difference in the Cobb angle (OR, 1.05) was the only factor for predicting midterm favorable outcomes after vertebral augmentation. The optimal cutoff value of the difference in the Cobb angle for predicting midterm favorable outcomes was 35.526°. CONCLUSION: We found that the midterm clinical outcome after vertebral augmentation was better when there was a difference of approximately 35% or more in the Cobb angle between the standing and supine positions. Surgeons should pay attention to the difference in the Cobb angle depending on the posture when deciding to perform vertebral augmentation in patients with OVCFs.

Influence of Triggering Events on the Occurrence of Spontaneous Intracranial Hemorrhage : Comparison of Non-Lesional Spontaneous Intraparenchymal Hemorrhage and Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVE: Spontaneous intracranial hemorrhage is a life-threatening disease, and non-lesional spontaneous intraparenchymal hemorrhage (nIPH) and aneurysmal subarachnoid hemorrhage (aSAH) are the leading causes of spontaneous intracranial hemorrhage. Only a few studies have assessed the association between prior physical activity or triggering events and the occurrence of nIPH or aSAH. The purpose of this study is to investigate the role of specific physical activities and triggering events in the occurrence of nIPH and aSAH. METHODS: We retrospectively reviewed 824 consecutive patients with spontaneous intracranial hemorrhage between January 2010 and December 2018. Among the 824 patients, 132 patients were excluded due to insufficient clinical data and other etiologies of spontaneous intracranial hemorrhage. The medical records of 692 patients were reviewed, and the following parameters were assessed : age, sex, history of hypertension, smoking, history of stroke, use of antiplatelet or anticoagulation agents, season and time of onset, physical activities performed according to the metabolic equivalents, and triggering event at onset. Events that suddenly raised the blood pressure such as sudden postural changes, defecation or urination, sexual intercourse, unexpected emotional stress, sauna bath, and medical examination were defined as triggering events. These clinical data were compared between the nIPH and aSAH groups. RESULTS: Both nIPH and aSAH most commonly occurred during non-strenuous physical activity, and there was no significant difference between the two groups (p=0.524). Thirty-two patients (6.6%) in the nIPH group and 39 patients (8.1%) in the aSAH group experienced triggering events at onset, and there was a significant difference between the two groups (p=0.034). The most common triggering events were defecation or urination in both groups. CONCLUSION: Specific physical activity dose no affect the incidence of nIPH and aSAH. The relationship between the occurrence of intracranial hemorrhage and triggering events is higher in aSAH than nIPH.

Transvenous Embolization of Dural Carotid Cavernous Fistula through the Supraorbital Vein.

We describe a case of transvenous embolization through the dilated supraorbital vein to treat a dural carotid cavernous fistula. The approach through the common facial vein or direct access of the superior ophthalmic vein is a commonly used route to the superior ophthalmic vein when the approach via the inferior petrosal sinus is unavailable. In rare cases, the dilated supraorbital vein provides an alternative route and we discuss the technical details.

Risk Factors and Preoperative Risk Scoring System for Shunt-Dependent Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVE: Shunt-dependent hydrocephalus (SdHCP) is a well-known complication of aneurysmal subarachnoid hemorrhage (SAH). The risk factors for SdHCP have been widely investigated, but few risk scoring systems have been established to predict SdHCP. This study was performed to investigate the risk factors for SdHCP and devise a risk scoring system for use before aneurysm obliteration. METHODS: We reviewed the data of 301 consecutive patients who underwent aneurysm obliteration following SAH from September 2007 to December 2016. The exclusion criteria for this study were previous aneurysm obliteration, previous major cerebral infarction, the presence of a cavum septum pellucidum, a midline shift of >10 mm on initial computed tomography (CT), and in-hospital mortality. We finally recruited 254 patients and analyzed the following data according to the presence or absence of SdHCP : age, sex, history of hypertension and diabetes mellitus, Hunt-Hess grade, Fisher grade, aneurysm size and location, type of treatment, bicaudate index on initial CT, intraventricular hemorrhage, cerebrospinal fluid drainage, vasospasm, and modified Rankin scale score at discharge. RESULTS: In the multivariate analysis, acute HCP (bicaudate index of ≥0.2) (odds ratio [OR], 6.749; 95% confidence interval [CI], 2.843-16.021; p=0.000), Fisher grade of 4 (OR, 4.108; 95% CI, 1.044-16.169; p=0.043), and an age of ≥50 years (OR, 3.938; 95% CI, 1.375-11.275; p=0.011) were significantly associated with the occurrence of SdHCP. The risk scoring system using above parameters of acute HCP, Fisher grade, and age (AFA score) assigned 1 point to each (total score of 0-3 points). SdHCP occurred in 4.3% of patients with a score of 0, 8.5% with a score of 1, 25.5% with a score of 2, and 61.7% with a score of 3 (p=0.000). In the receiver operating characteristic curve analysis, the area under the curve (AUC) for the risk scoring system was 0.820 (p=0.080; 95% CI, 0.750-0.890). In the internal validation of the risk scoring system, the score reliably predicted SdHCP (AUC, 0.895; p=0.000; 95% CI, 0.847-0.943). CONCLUSION: Our results suggest that the herein-described AFA score is a useful tool for predicting SdHCP before aneurysm obliteration. Prospective validation is needed.

Intraoperative Ventriculostomy Using K Point in Surgical Management of Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Intraoperative ventriculostomy in the surgical management of aneurysmal subarachnoid hemorrhage (SAH) is frequently performed to reduce increased intracranial pressure. The previously suggested ventriculostomy points have some limitations because the dura mater must be opened to be accessed and it is difficult to measure the exact entry point in patients with brain edema. We propose a new intraoperative ventriculostomy point (K point) for use in the surgical management of aneurysmal SAH patient with severe brain edema. METHODS: We performed intraoperative ventriculostomy using the K point on 155 patients with aneurysmal SAH between January 2012 and August 2016. Before opening the dura mater following standard pterional craniotomy, we inserted the ventricular catheter through a small dural incision perpendicular to the middle frontal gyrus toward the ipsilateral medial epicanthus. We simulated the catheter trajectory using a commercial navigation system on 2 patients with brain tumor. RESULTS: Ventriculostomy related hemorrhage occurred in 12 patients (7.7%), but there were no large hemorrhages causing neurologic deterioration or requiring evacuation. No language impairment was observed in these patients. Analysis using the navigation system revealed that the trajectory of K point ventriculostomy avoided critical periventricular brain structures and passed through the space between the genu of the corpus callosum and head of the caudate nucleus. CONCLUSIONS: K point ventriculostomy allows for easy access to a target point and protects the brain during opening of the dura mater and drilling of the sphenoid bone.

Bone Flap Resorption Following Cranioplasty with Autologous Bone: Quantitative Measurement of Bone Flap Resorption and Predictive Factors.

OBJECTIVE: To quantitatively measure the degree of bone flap resorption (BFR) following autologous bone cranioplasty and to investigate factors associated with BFR. METHODS: We retrospectively reviewed 29 patients who underwent decompressive craniectomy and subsequent autologous bone cranioplasty between April 2005 and October 2014. BFR was defined as: 1) decrement ratio ([the ratio of initial BF size/craniectomy size]-[the ratio of last BF/craniectomy size]) >0.1; and 2) bone flap thinning or geometrical irregularity of bone flap shape on computed tomographic scan or skull plain X-ray. The minimal interval between craniectomy and cranioplasty was one month and the minimal follow-up period was one year. Clinical factors were compared between the BFR and no-BFR groups. RESULTS: The time interval between craniectomy and cranioplasty was 175.7±258.2 days and the mean period of follow up was 1364±886.8 days. Among the 29 patients (mean age 48.1 years, male: female ratio 20: 9), BFR occurred in 8 patients (27.6%). In one patient, removal of the bone flap was carried out due to severe BFR. The overall rate of BFR was 0.10±0.11 over 3.7 years. Following univariate analysis, younger age (30.5±23.2 vs. 54.9±13.4) and longer follow-up period (2204.5±897.3 vs. 1044.1±655.1) were significantly associated with BFR (p=0.008 and 0.003, respectively). CONCLUSION: The degree of BFR following autologous bone cranioplasty was 2.7%/year and was associated with younger age and longer follow-up period.

Impact of Time Interval between Trauma Onset and Burr Hole Surgery on Recurrence of Late Subacute or Chronic Subdural Hematoma.

OBJECTIVE: Although subdural hematoma (SDH) is commonly treatable by burr hole surgery in the late subacute or chronic stage, there is no clear consensus regarding appropriate management and exact predictive factors for postoperative recurrence also remain unclear. The aim of this study was to evaluate risk factors associated with recurrence of SDH that requires burr hole surgery in the late subacute or chronic stage. We also identified the appropriate timing of surgery for reducing the recurrence. METHODS: We retrospectively reviewed 274 patients with SDH in the late subacute or chronic stage treated with burr hole surgery in our hospital between January 2007 and December 2014. Excluding patients with acute intracranial complications or unknown time of trauma onset left 216 patients included in the study. RESULTS: Of 216 patients with SDH in the late subacute or chronic stage, recurrence was observed in 36 patients (16.7%). The timing of the operation in patients with late subacute stage (15-28 days) resulted in a significant decrease in recurrence (RR, 0.33; 95% CI, 0.17-0.65; p=0.001) compared to chronic stage (>28 days). Otherwise, no significant risk factors were associated with recurrences including comorbidities and surgical details. CONCLUSION: The results indicated that time from trauma onset to burr hole surgery may be important for decreasing the risk of recurrence. Therefore, unless patients can be treated conservatively without surgery, prompt surgical management is recommended in patients diagnosed as having late subacute or chronic subdural hematoma treatable by burr hole surgery, even when neurological deficits are unclear.

High-Dose Simvastatin Is Effective in Preventing Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study in Korean Patients.

OBJECTIVE: The goal of this study was to assess the effect of high-dose simvastatin on cerebral vasospasm and its clinical outcome after aneurysmal subarachnoid hemorrhage (SAH) in Korean patients. METHODS: This study was designed as a prospective observational cohort study. Its subjects were aneurysmal SAH patients who had undergone aneurysm clipping or coiling. They were assigned to 1 of 3 groups : the 20 mg, 40 mg, and 80 mg simvastatin groups. The primary end-point was the occurrence of symptomatic vasospasm. The clinical outcome was assessed with the modified Rankin Scale (mRS) score after 1 month and 3 months. The risk factors of the development of vasospasm were assessed by logistic regression analysis. RESULTS: Ninety nine patients with aneurysmal SAH were treated and screened. They were sequentially assigned to the 20 mg (n=22), 40 mg (n=34), and 80 mg (n=31) simvastatin groups. Symptomatic vasospasm occurred in 36.4% of the 20 mg group, 8.8% of the 40 mg group, and 3.2% of the 80 mg group (p=0.003). The multiple logistic regression analysis showed that poor Hunt-Hess grades (OR=5.4 and 95% CI=1.09-26.62) and high-dose (80 mg) simvastatin (OR=0.09 and 95% CI=0.1-0.85) were independent factors of symptomatic vasospasm. The clinical outcomes did not show a significant difference among the three groups. CONCLUSION: This study demonstrated that 80 mg simvastatin treatment was effective in preventing cerebral vasospasm after aneurysmal SAH, but did not improve the clinical outcome in Korean patients.

Age and meteorological factors in the occurrence of spontaneous intracerebral hemorrhage in a metropolitan city.

OBJECTIVE: The aim of this study was to investigate the correlation between meteorological factors and occurrence of spontaneous intracerebral hemorrhage (ICH) according to age. MATERIALS AND METHODS: We retrospectively analyzed the records of 735 ICH patients in a metropolitan hospital-based population. Observed and expected numbers of ICH patients were obtained at 5℃ intervals of ambient temperature and a ratio of observed to expected frequency was then calculated. Changes in ambient temperature from the day before ICH onset day were observed. The Wilcoxon-Mann-Whitney test was used to test differences in meteorological variables between the onset and non-onset days. The Kruskal-Wallis test was used for comparison of meteorological variables across gender and age. RESULTS: ICH was observed more frequently (observed/expected ratio ≥ 1) at lower mean, minimum, and maximum ambient temperature (p = 0.0002, 0.0003, and 0.0002, respectively). Significantly lower mean, minimum, and maximum ambient temperature, dew point temperature, wind speed, and atmospheric pressure (p = 0.0003, 0.0005, 0.0001, 0.0013, 0.0431, and 0.0453, respectively) was observed for days on which spontaneous ICH occurred. In the subgroup analysis, the ICH onset day showed significantly lower mean, minimum, and maximum ambient temperature, dew point temperature, relative humidity, and higher atmospheric pressure in the older (≥ 65 years) female group (p = 0.0093, 0.0077, 0.0165, 0.0028, 0.0055, and 0.0205, respectively). CONCLUSION: Occurrence of spontaneous ICH is closely associated with meteorological factors and older females are more susceptible to lower ambient temperature.

The sundt encircling clip as a vascular rescue: a case report and a review of repair methods for arterial tearing.

The Sundt encircling clip was developed to repair defects of the vessel wall. With the advent of microvascular techniques, most parts of the damaged vessel wall during aneurysm surgery can be repaired by primary closure or by the bypass technique. However, these methods are not always successful. Here, we illustrate two cases of surgical clipping with the Sundt encircling clip in the ruptured internal carotid artery trunk aneurysm. The Sundt clip provides prompt control of unexpected tearing of the vessel wall or aneurysm and plays an important role in vascular rescue during aneurysm surgery.

Thrombosis and recanalization of small saccular cerebral aneurysm : two case reports and a suggestion for possible mechanism.

Reports of thrombosis and recanalization of cerebral aneurysm are rare. We report two cases of small, saccular aneurysms in which spontaneous thrombosis had occurred during the preparation for endovascular coiling. Also, we review reported cases and propose the presumed pathogenesis.

The usefulness of compliant balloon for recanalization of acute ischemic stroke.

OBJECTIVE: We report on our experience using a compliant balloon for treatment of thrombi resistant to simple mechanical thrombolysis. METHODS: We conducted a retrospective investigation of 46 consecutive acute ischemic stroke patients who were treated by intraarterial thrombolysis (IAT) between January 2008 and July 2010. We compared IAT results between the balloon group (BG) and the simple mechanical thrombolysis (with microcatheter and microguidewire) group (SG). The Thrombolysis in Myocardial Infarction (TIMI) grading system was used for grading of the degrees of vessel recanalization. In addition, a modified Thrombolysis in Cerebral Infarction (TICI) score was used for post-IAT TIMI grade 2 patients. Modified Rankin Scale scores were used at three months for assessment of clinical outcomes. RESULTS: Twenty of the 46 subjects were treated with a compliant balloon. The mean initial National Institutes of Health Stroke Scale score was 15.1 in the BG and 14 in the SG. The mean time from symptom onset to initiation of IAT was 225 minutes in the BG and 177 in the SG (p = 0.004). The overall rate of successful recanalization (TIMI grade 2 or 3) was 85% in the BG and 73% in the SG (p = 0.476). In the TIMI grade 2 group, modified TICI 2b was 90% in the BG and 16% in the SG (p = 0.001). Postprocedure intraparenchymal hemorrhage occurred in two subjects in the BG and 10 subjects in the SG (p = 0.029). No significant difference in clinical outcomes was observed between the BG and SG (p = 0.347). CONCLUSIONS: The compliant balloon showed high potential for recanalization following acute ischemic stroke, especially when simple mechanical thrombolysis had failed.

Risk factors affecting clinical outcome of ruptured vertebrobasilar saccular aneurysms.

OBJECTIVE: Ruptured vertebrobasilar (VB) saccular aneurysm is a difficult lesion to treat, and is associated with high rates of morbidity and mortality. The aim of this study is to investigate the risk factors associated with the clinical outcome of ruptured VB aneurysms. METHODS: A retrospective review of 29 patients with ruptured VB saccular aneurysms between 2002 and 2010 was conducted between Jan 2002 and Dec 2010. Univariate and multivariate analyses were performed for determination of the statistical significance of the Glasgow Outcome Scale (GOS) at three months, according to age, initial Hunt-Hess grade, the presence of acute hydrocephalus, and treatment modality. RESULTS: The study included 24 (82.7%) females and five (17.3%) males, with a mean age of 59 years (range, 22-78 years). Seventeen patients were treated with surgical clipping and 12 patients were treated with endovascular coil embolization. No statistical significance was observed between clinical outcome and treatment modalities (clipping or coiling; p = 0.803). Seventeen (58.6%) patients achieved favorable outcome, defined as GOS score of 4-5, at 3 months. Procedure-related complications occurred in seven patients (24.1%). Results of multivariate analysis indicated that initial Hunt-Hess grade and the presence of acute hydrocephalus were independent predictors of unfavorable outcome, defined as GOS score of 1-3 (Odds ratio (OR) = 8.63, Confidence interval (CI) [95%] 1.11-66.84, p = 0.039 and OR = 36.64, CI [95%] 2.23-599.54, p = 0.012, respectively). CONCLUSION: The present study suggests that the clinical outcomes are related to the initial Hunt-Hess grade and the presence of acute hydrocephalus in ruptured saccular VB aneurysms.

Bilateral Approach for Stent-assisted Coiling of Posterior Inferior Cerebellar Artery Aneurysms - Two Cases.

Aneurysms of the posterior inferior cerebellar artery (PICA) are rarely encountered. In particular, due to frequent anatomic complexity and the presence of nearby critical structures, PICA origin aneurysms are difficult to treat. However, recent reports of anecdotal cases using advanced endovascular instruments and skills have made the results of endovascular treatment rather outstanding. PICA preservation is the key to a successful endovascular treatment, based on the premise that a PICA origin aneurysm is well occluded. To secure PICA flow, stenting into the PICA would be the best method, however, it is nearly impossible technically via the ipsilateral vertebral artery (VA) if the PICA arose at an acute angle from the sac. In such a case, a bilateral approach for stent-assisted coiling can be a creative method for achievement of two goals of both aneurysm occlusion and PICA preservation: ipsilateral approach for coil delivery and contralateral cross-over approach for stent delivery via a retrograde smooth path into the PICA.