Seung Kon Huh

Hemorrhagic complications related to the stent-remodeled coil embolization of intracranial aneurysms.

OBJECTIVETo evaluate the postprocedural hemorrhagic complications associated with stent-remodeled coil embolization of intracranial aneurysms. METHODSFrom the database of 163 cases of stent-remodeled therapy for wide-neck intracranial aneurysms, patients who showed intracranial hemorrhagic complications on follow-up brain imaging were selected. The initial presentation, antithrombotic medication, hemorrhagic type, location, amount, association with ventriculostomy, symptomatic involvement, and outcome were assessed. RESULTSTen patients (6.1%) developed intracranial hemorrhagic complications (range; 0–422 days; mean; 56 days). The hemorrhagic complication rate was higher in patients with acute subarachnoid hemorrhage (20%, 6 of 30 patients) than in patients with unruptured aneurysms (3%, 4 of 133 patients). Nine of the 10 patients were on dual-antiplatelet therapy at the time of hemorrhage development. Seven of the hemorrhages developed in patients with ventriculostomies (intraparenchymal, n = 4; subdural hematoma, n = 3). Three patients who did not receive a ventriculostomy also developed intracranial hemorrhage (n = 1) or intraparenchymal hemorrhage (n = 2). Hemorrhagic transformation in the recently infarcted brain tissue seemed to be the cause of nonventriculostomy related intraparenchymal hemorrhage. The hemorrhages were accompanied by symptomatic aggravation in 6 of 10 cases, with 5 cases resulting in moribund clinical outcome. CONCLUSIONPostprocedural intracranial hemorrhage may be a risk of stent-remodeled therapy while the patient is on dual-antiplatelet medication. Extra caution is warranted especially in patients with acute subarachnoid hemorrhage requiring ventriculostomy or with underlying recent brain infarction.

Gamma Knife surgery for large cerebral arteriovenous malformations

OBJECT Treatment of arteriovenous malformations (AVMs) is problematic due to many factors, including lesion size, lesion location, unacceptable complications, and negative outcomes. To overcome the limitation imposed by a large nidus volume, neurosurgeons have used Gamma Knife surgery (GKS) in a variety of ways, including combined with other treatment modalities, as volume-staged radiosurgery, and as repeat radiosurgery. We performed repeat radiosurgeries in patients who harbored large AVMs (> 30 cm(3)) and analyzed the AVM obliteration rates and complications. METHODS The authors reviewed the cases of 44 patients at a single institution who underwent GKS between 1992 and 2007 for treatment of an AVM whose nidus was 30 cm(3) or larger. The mean age of the patients was 27 years (range 4.5-62.3 years), and the median duration of follow-up was 109.4 months (range 27-202 months). The mean AVM nidus volume was 48.8 cm(3) (range 30.3-109.5 cm(3)), and the mean radiation dose delivered to the margin of the nidus was 13.9 Gy (range 8.4-17.5 Gy). The authors determined complete AVM nidus obliteration based on findings on both MR images and digital subtraction angiograms. When they did not detect complete obliteration after GKS, they performed 1 or more additional GKSs separated by a minimum interval of 3 years. RESULTS The overall obliteration rate following repeat GKS was 34.1%, and the estimated obliteration rate at 120 months was 41.8%. Three patients (6.8%) experienced hemorrhages after GKS, and 2 patients (4.5%) developed cysts. One patient (2.3%) experienced a newly developed seizure following GKS, and another patient (2.3%) was found to have radiation necrosis. CONCLUSIONS Even though complete obliteration of the large AVMs after repeat GKS took a long time, the complication rate was quite acceptable. In addition, the estimated obliteration rate at long-term follow-up was respectable. Repeat GKS should be considered as a primary treatment option for symptomatic large AVMs to overcome the limitation imposed on successful obliteration by the large volume of the nidus.

MR-DWI–Positive Lesions and Symptomatic Ischemic Complications After Coiling of Unruptured Intracranial Aneurysms

Background and Purpose— The aims of this study are to evaluate the risk factors for symptomatic ischemic complication (symptomatic ischemic complication [SIC], transient ischemic attack, or stroke) and microembolisms detected as MR diffusion-weighted imaging (MR-DWI)–positive (DWI(+)) lesions, and the relationship between DWI(+) and SIC after coiling of unruptured intracranial aneurysm. Methods— Between March 2009 and November 2011, 382 unruptured intracranial aneurysms in 343 patients underwent both coiling and posttreatment MR-DWI. The incidence of and risk factors for SIC and DWI(+), and the relationship between DWI(+) and SIC were retrospectively analyzed. Results— The incidence of SIC was 4.1%. The incidence of DWI(+) was 54.5%. The number of DWI(+) lesions was significantly larger in the SIC group, than in the asymptomatic one (12.1±10.4 versus 5.0±8.7, P<0.00). The cutoff value of DWI(+) for predicting SIC was ≥6 (sensitivity 85.7%, specificity 70.7%). The patients with DWI(+) ≥6 was 28.6%. Of the patients with SIC, the patients with DWI(+) ≥6 was 78.6%. Patients aged≥65 years had a trend for SIC, and it was the only independent risk factor for DWI(+) ≥cutoff (n=6; 95%CI, 1.167–3.083). Conclusions— The number of DWI(+) lesions was significantly larger in the SIC group than in the asymptomatic one after coiling of unruptured intracranial aneurysm. Patients aged≥65 had a trend for SIC, and it was the only independent risk factor for the number of DWI(+) ≥cutoff value (n=6) for predicting SIC.

Surgery for distal anterior cerebral artery aneurysms

BACKGROUND Because DACA aneurysms are located in the narrow interhemispheric space surrounded by the corpus callosum and bilateral cingulate gyri with intervening falx cerebri, they are considered some of the most difficult anterior circulation aneurysms to surgically treat. Moreover, because of their rare occurrence and the emerging nonsurgical treatment options, neurosurgeons are limited in their ability to surgically treat DACA aneurysms due to their lack of experience. This article describes details of the preoperative considerations, operative techniques, and surgical results for DACA aneurysms. METHODS Medical records, including imaging studies, surgeons hand drawings and descriptions of microsurgical findings, microphotographs, and video records of operative procedures, were reviewed. RESULTS Among 3577 patients with intracranial aneurysms treated since 1975, 126 (3.5%) patients with DACA aneurysms were identified. They were treated either by surgery (117 patients) or endovascular treatment (9 patients). The results of surgical treatment for the 117 patients with DACA aneurysms were favorable in 94% (90.6% good and 3.4% fair) and unfavorable in 6% (5.1% poor and 0.9% dead). All unfavorable outcomes occurred in patients who were of preoperative grades 4 or 5. CONCLUSIONS Successful surgical management of DACA aneurysms depends on precise understanding of their unique microsurgical anatomy, avoidance of pitfalls, and the surgeons experience. Sufficient brain relaxation, accurate localization of the aneurysm, early identification of the proximal A2 segment, and preservation of the major draining veins are necessary for a safe surgery.

Emergency surgical recanalisation of A1 segment occluded by a Guglielmi detachable coil.

We describe a case of A1 segment occlusion caused by a tangled Guglielmi detachable coil (GDC) during an endovascular treatment for a ruptured anterior communicating aneurysm. Immediate surgical recanalisation of the occluded artery and clipping of the aneurysm rescued the patient. This case demonstrates that an emergency surgical team, as well as an operating room, should be available during any complicated intra-aneurysmal procedure, so that timely surgical intervention could be carried out without delay.

Morphological parameters related to ruptured aneurysm in the patient with multiple cerebral aneurysms (clinical investigation).

Abstract Objectives: We evaluated the rupture risk of multiple cerebral aneurysms in aspects of various morphological parameters, and determined which parameter can be a reliable predictor as one aneurysm ruptured, and the others did not. Methods: Between 2007 and 2012, three-dimensional (3D) angiographic images of 85 patients harboring multiple aneurysms (85 ruptured and 104 unruptured aneurysms) were used to assess the following morphological parameters: geometry of the aneurysm itself, e.g. maximal size, aspect ratio, bottleneck ratio, height/width ratio, undulation, and daughter sac; architecture of the aneurysm and surrounding vessels, e.g. aneurysmal angle, vessel angle, inflow angle, parent–daughter angle, and size ratio type I & II. Univariate analysis was applied to all parameters, and significant parameters were identified in multivariate analysis, yielding the cut-off point from receiver-operating characteristic (ROC) curve analysis. Results: On multivariate logistic regression, the aspect ratio [odds ratio (OR), 1·21; 95% confidence interval (CI), 1·05–1·41] and daughter sac (OR, 3·12; 95% CI, 1·05–9·27) were significant parameters in geometries of the aneurysm itself. The size ratio type I (OR, 1·14; 95% CI, 1·05–1·22) and parent–daughter angle (OR, 1·02; 95% CI, 1·00–1·04) were independent parameters in architecture of the aneurysm and surrounding vessels. From the ROC curve, the aspect ratio and size ratio type I had cut-off values of 1·3 and 1·8, respectively. Conclusion: Several morphological parameters were investigated to predict a rupture in multiple cerebral aneurysms using 3D angiogram. The aspect ratio, size ratio type I, daughter sac, and parent–daughter angle were revealed as competent parameters.

Outcomes of multidisciplinary treatment for posterior cerebral artery aneurysms.

OBJECTIVE Posterior cerebral artery (PCA) aneurysms are rare and often challenging to manage. Since Drakes historical report regarding PCA aneurysms, there has been limited additional information on recent advancements in either microsurgical or endovascular tools. We report a series of 25 consecutive cases and attempt to extrapolate useful information for managing PCA aneurysms. METHODS A total of 25 cases of PCA aneurysm that were treated either by microsurgical or endovascular methods were selected and retrospectively reviewed. The clinical data, radiographic findings, and outcomes associated with the treatment modality were analysed. RESULTS The case series included 13 women and 12 men with a mean age of 52 years, ranging from 11 to 75 years. Fourteen aneurysms were ruptured, 7 aneurysms caused a direct mass effect, and the remaining 4 aneurysms were found incidentally. Most aneurysms were located in the P1 through P2A segment of the PCA (19 aneurysms, 76%). Seven aneurysms (28%) were large-giant in size (>20 mm), 4 of which had a thrombosed sac. Microsurgical treatment was the primary treatment in 15 aneurysms, including 9 successful direct clip ligations, 3 aneurysms that were surgically trapped without a bypass, and 2 wrapped aneurysms. One giant thrombosed aneurysm was incompletely clipped; subsequently, the large remnant was coil-embolised. Endovascular coil embolisation was performed for 6 aneurysms, stent-assisted coil embolisation was performed for 2 aneurysms, and 2 aneurysms were treated by endovascular occlusion of the parent artery. Permanent deficits acquired after treatment included limb weakness, palsy of the third cranial nerve, and hemianopsia in 5 cases (20%). There was no mortality. Overall, 22 patients (88%) showed favourable clinical outcomes according to the modified Rankin Scale Score (≤2) at the mean clinical follow-up period of 43.2 months (range: 2-130 months). CONCLUSIONS The present case series suggests that treating PCA aneurysms with microsurgical or endovascular options can achieve a comparable outcome when a judicious decision is made. Endovascular treatment had excellent anatomical and clinical outcomes for non-mass compressing, non-giant, saccular aneurysms. Given the propensity for the large-giant, dysplastic nature of PCA aneurysms to develop in younger patients, microsurgical competence should be maintained. Along with careful evaluation of the anatomic collaterals over the PCA territory, therapeutic parent artery sacrifice may be an appropriate option without adding bypass.

Microsurgical efficacy and safety of a right-hemispheric approach for unruptured anterior communicating artery aneurysms.

OBJECTIVE We investigated the effectiveness of a right hemispheric surgical approach in treating unruptured anterior communicating artery aneurysms. METHODS Between January 2005 and June 2012, 305 patients with anterior communicating artery (Acom) aneurysms were treated using the pterional approach. Among them, 113 who underwent microsurgery with an unruptured Acom aneurysm were enrolled in this study. Every patient was evaluated with digital subtraction angiography preoperatively and CT scans were taken several times postoperatively. Surgical outcomes and complications were evaluated at discharge using the Glasgow Outcome Scale and at 6 months after surgery with CT angiography. RESULTS Enrolled patients included 55 males and 58 females with a mean age of 56.3 years (range: 30-75 years). The mean diameter of the aneurysm was 5.8mm (range: 1.9-24.1). Left A1 dominancy was found in 71 patients (62.8%) whereas right A1 dominancy was found in 20 patients (17.7%), and right pterional craniotomies were performed in 92 patients (81.4%) while left pterional craniotomies were performed in 21 patients (18.6%). Complete clip application was achieved in 94.9% of patients (74 of 78) in right-side approach group but in only 81.3% of patients (13 of 16) in left-side approach group. Despite a left A1 dominancy and approached from the right, more than 90% of the patients had an excellent outcome at discharge (GOS 5) and more than 90% a complete aneurysm clipping at the 6-month follow-up CT angiography although it was not statistically significant. CONCLUSION Microsurgical clipping of the unruptured Acom aneurysm through a right-side surgical approach showed favorable postoperative clinical and anatomical outcomes, especially aneurysms smaller than 10mm.

The Role of Endovascular Treatment for Ruptured Distal Anterior Cerebral Artery Aneurysms: Comparison with Microsurgical Clipping

The purpose of this study was to compare clinical outcomes and treatment‐related complications between coiling and clipping for ruptured distal anterior cerebral artery (DACA) aneurysms.

Surgical outcomes after classifying Grade III arteriovenous malformations according to Lawton's modified Spetzler-Martin grading system.

OBJECTIVE We aimed to evaluate microsurgical outcomes after classifying Grade III arteriovenous malformations (AVMs) according to Lawtons modified Spetzler-Martin grading system. METHODS Of 131 patients with Grade III AVMs, 55 had undergone microsurgery between 1995 and 2010. The 55 AVMs were classified as follows: Grade III-/S1E1V1, Grade III/S2E0V1, Grade III+/S2E1V0, or Grade III*/S3E0V0. The surgical obliteration rate, morbidity rate, and functional outcomes for each subtype were compared before surgery and after follow-up. Additionally, factors related with morbidity were investigated from demographic and morphological characteristics. RESULTS We observed 18 Grade III-, 16 Grade III, 20 Grade III+, and 1 Grade III* AVMs. Complete resection was achieved in 49 patients (obliteration rate, 89.1%). Incomplete resection rates were higher for Grade III (12.5%) and III+ (15.0%) AVMs than that for Grade III- (5.6%) AVMs. Seven patients (12.7%) presented postoperative deficits, of which 3 (5.4%) experienced disabilities. Patients with Grade III+ (25.0%) had higher morbidity rates than those with other subtypes. Modified Rankin scale scores at the last follow-up indicated unfavorable outcomes for Grades III (18.8%) and III+ (25.0%) AVMs. AVM size (≥3 cm) and non-hemorrhagic type were associated with the occurrence of postoperative deficits (p<0.05). CONCLUSION The modified classification of Grade III AVMs was useful to predict surgical morbidity and clinical outcomes. We recommend that microsurgery should be used to treat Grade III- AVMs, but should be considered carefully for the treatment of Grades III and III+.