Comparative Analysis of Feasibility of the Retrograde Suction Decompression Technique for Microsurgical Treatment of Large and Giant Internal Carotid Artery Aneurysms.

OBJECTIVE: Retrograde suction decompression (RSD) is an adjuvant technique used for the microsurgical treatment of large and giant internal carotid artery (ICA) aneurysms. In this study, we analyzed the efficacy and safety of the RSD technique for the treatment of large and giant ICA aneurysms relative to other conventional microsurgical techniques. METHODS: The aneurysms were classified into two groups depending on whether the RSD method was used (21 in the RSD group vs. 43 in the non-RSD group). Baseline characteristics, details of the surgical procedure, angiographic outcomes, clinical outcomes, and procedure-related complications of each group were reviewed retrospectively. RESULTS: There was no significant difference in the rates of complete neck-clipping between the RSD (57.1%) and non-RSD (67.4%) groups. Similarly, there was no difference in the rates of good clinical outcomes (modified Rankin Scale score, 0-2) between the RSD (85.7%) and non-RSD (81.4%) groups. Considering the initial functional status, 19 of 21 (90.5%) patients in the RSD group and 35 of 43 (81.4%) patients in the non-RSD group showed an improvement or no change in functional status, which did not reach statistical significance. CONCLUSION: In this study, the microsurgical treatment of large and giant intracranial ICA aneurysms using the RSD technique obtained competitive angiographic and clinical outcomes without increasing the risk of procedure-related complications. The RSD technique might be a useful technical option for the microsurgical treatment of large and giant intracranial ICA aneurysms.

Recurrence and risk factors of posterior communicating artery aneurysms after endovascular treatment.

BACKGROUND: Endovascular treatment (EVT) of posterior communicating artery aneurysms (PcomA) is challenging because of posterior communicating artery (Pcom) architecture. Additionally, these aneurysms have a high risk of recanalization compared with those located elsewhere. METHODS: The radiographic findings of 171 patients treated with EVT at two institutions were retrospectively reviewed. Univariate and multivariate analyses were performed, and subgroup analyses were performed based on Pcom characteristics. RESULTS: Recanalization of PcomAs occurred in 53 patients (30.9%). Seven patients (4.0%) were retreated (six endovascularly and one with microsurgical clipping). The mean follow-up duration was 27.7 months (range: 3.5-78.6). The maximum diameter (odds ratio [OR] 1.23, P = .006, 95% CI 1.07-1.44), a Raymond-Roy classification of grade II or III (OR 2.26, P = .03, 95% CI 1.08-4.82), and the presence of reinforcement (balloon or/and stent, OR 0.44, P = .03, 95% CI 0.20-0.91) were associated with recanalization using multivariate logistic regression. Significant differences were found in maximum aneurysm diameter (P = .03) between normal- and fetal-type Pcoms on analysis of variance. CONCLUSIONS: The recanalization rate of PcomAs after EVT was 30.9%; the retreatment rate was 4.0%. Maximum diameter, Raymond-Roy classification, and presence of reinforcement were significantly associated with recanalization but not associated with fetal-type Pcom. Aneurysm size was larger in patients with a fetal-type Pcom than in those with a normal Pcom. Pcom size was not related to recanalization rate.

Recurrence and retreatment of anterior communicating artery aneurysms after endovascular treatment: a retrospective study.

BACKGROUND: Surgical treatment of anterior communicating artery (Acom) aneurysm is challenging due to anatomic complexity. We aimed to describe our experiences with endovascular treatment (EVT) of Acom aneurysms, and to evaluate the incidence and risk factors of recurrence and retreatment. METHODS: The study comprised 260 patients who were treated at a single center between January 2010 and December 2018. Patients who had EVT, including stent-assisted coiling of Acom aneurysms, were included. All medical records were retrospectively reviewed. The incidence and risk factors of recurrence and retreatment were evaluated. Univariate and multivariate analysis were conducted. RESULTS: Recurrence of Acom aneurysms occurred in 38 (14.6%) patients. Mean follow-up duration was 27 months (range 1-110). Multivariate logistic regression indicated that ruptured aneurysm (odds ratio [OR] 3.55, P = 0.001), dome direction (anterior) (OR 3.86, P = 0.002), maximal diameter (OR 1.19, P = 0.02), and mean age (OR 0.96, P = 0.02) were independent risk factors for aneurysm recurrence. Of 38 cases of recurrence, 10 (3.8%) patients underwent retreatment. Ruptured aneurysm (OR 14.7, P = 0.004), maximal diameter (OR 1.56, P = 0.02), inflow angle (OR 1.04, P = 0.03), and Raymond-Roy classes II and III (OR 6.19, P = 0.03) showed significant relation to retreatment in multivariate logistic regression analysis. CONCLUSIONS: In our study, recurrence rate of Acom aneurysms after EVT was 14.6%. Rupture, anterior dome direction, maximal diameter, and mean age were significantly associated with recurrence. Retreatment rate of recurrent Acom aneurysms after EVT was 3.8%. Patients with Acom aneurysms with large inflow, rupture, large size, or incomplete occlusion may be at a high risk of retreatment of recurring aneurysm.

Microsurgical clipping of ruptured anterior choroidal artery aneurysms: Incidence of and risk factors for ischemic complications.

OBJECTIVE: Temporary clipping of the internal carotid artery can be required during microsurgery of a ruptured anterior choroidal artery (AchoA) aneurysm. Although it is suspected that such temporary clipping might be related to ischemic complications following surgery, no detailed analysis has been reported yet. PATIENTS AND METHODS: Eighty-nine patients with ruptured AchoA aneurysms treated by microsurgical clipping were recruited between January 1996 and December 2017. Patient medical records, radiographic data, and intraoperative video findings were retrospectively reviewed. Multivariate logistic regression analysis was conducted to investigate the risk factors for treatment-related ischemic complications. RESULTS: Treatment-related ischemic complications occurred in eight (9.0 %) patients, all of whom underwent temporary clipping during microsurgery. Patients who did not undergo temporary clipping (n = 20) did not experience treatment-related ischemic complications. Among patients who underwent temporary clipping (n = 69), multivariate logistic regression analyses indicated that the total duration, number of attempts, and longest time per attempt were not risk factors for poor clinical outcome at discharge. However, the longest time per attempt was identified as the only independent risk factor for treatment-related ischemic complications (odds ratio, 2.883; 95 % confidence interval, 1.725-6.525; P = 0.042). CONCLUSION: The longest time per attempt might be associated with a higher risk of treatment-related ischemic complications during microsurgery for ruptured AchoA aneurysms. Treatment-related ischemic complications may be minimized by intermittent application of temporary clipping during surgery.

Usefulness of high-resolution three-dimensional proton density-weighted turbo spin-echo MRI in distinguishing a junctional dilatation from an intracranial aneurysm of the posterior communicating artery: a pilot study.

BACKGROUND: Discriminating a junctional dilatation from a true saccular aneurysm is clinically important. PURPOSE: To evaluate the usefulness of high-resolution three-dimensional proton density-weighted turbo spin-echo magnetic resonance imaging (PD MRI) in distinguishing a junctional dilatation from an aneurysm of the posterior communicating artery (PcomA). METHODS: Eighty-two consecutive patients with 83 PcomA lesions, which were evaluated by time-of-flight (TOF) MR angiography (MRA), PD MRI, and digital subtraction angiography (DSA), were enrolled. These radiologic data were retrospectively and independently reviewed by two neurosurgeons, and each diagnosis based on TOF MRA, PD MRI, and DSA was compared. The diagnostic efficacy (interobserver agreement, intermodality agreement, and diagnostic performance) of PD MRI was compared with that of TOF MRA. RESULTS: PD MRI showed higher AC1 (Gwet's agreement coefficient, PD MRI: 0.8942, 95% CI 0.8204 to 0.968; TOF MRA: 0.7185, 95% CI 0.5753 to 0.8617) and prevalence-adjusted bias-adjusted kappa coefficient (PABAK) (PD MRI: 0.8554, TOF MRA: 0.5904) than TOF MRA for interobserver agreement. For intermodality agreement, PD MRI also showed higher AC1 (PD MRI: 0.9069, 95% CI 0.8374 to 0.9764; TOF MRA: 0.7983, 95% CI 0.6969 to 0.8996) and PABAK (PD MRI: 0.8735, TOF MRA: 0.7289) than TOF MRA. The diagnostic performance of PD MRI was statistically superior to that of TOF MRA in sensitivity, specificity, positive predictive value, and negative predictive value. CONCLUSIONS: PD MRI could provide excellent diagnostic accuracy and better information in distinguishing a junctional dilatation from a true saccular aneurysm of the PcomA compared with TOF MRA.

Microsurgical Treatment of Unruptured Anterior Choroidal Artery Aneurysms: Incidence of and Risk Factors for Procedure-Related Complications.

OBJECTIVE: To describe our experiences with microsurgical treatment of unruptured anterior choroidal artery (AchA) aneurysms, and to evaluate the incidence of and risk factors for procedure-related complications. METHODS: The study included 110 patients treated between January 2012 and December 2016. All patients met the following criteria: 1) microsurgical treatment of an unruptured AchA aneurysm was performed; and 2) clinical and radiographic follow-up data were available, including findings from preoperative digital subtraction angiography. The incidence of and risk factors for procedure-related complications were retrospectively evaluated. The χ2 test and Mann-Whitney U test were used in statistical analysis, and univariate analysis and multivariate logistic regression analysis were conducted. RESULTS: Procedure-related complications occurred in 5 patients (4.5%), including symptomatic complications in 4 patients (3.6%) and asymptomatic complications in 1 patient (0.9%). Multivariate logistic regression analysis indicated that the angle between the vertical line to the cranial base and the axis of the communicating segment of the internal carotid artery (MiC angle) (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.13-5.26; P = 0.038) and the angle between the projection line of the aneurysmal dome and the axis of the communicating segment of the internal carotid artery (DC angle) (OR, 3.82; 95% CI, 1.49-11.7; P = 0.014) were independent risk factors for procedure-related complications. CONCLUSIONS: When microsurgical treatment of unruptured AchA aneurysms was performed, the procedure-related complication rate was 4.5%. Patients with AchA aneurysms with a smaller MiC angle and smaller DC angle may be at a higher risk of procedure-related complications when undergoing microsurgical treatment.

Therapeutic strategies for residual or recurrent intracranial aneurysms after microsurgical clipping.

OBJECTIVES: Therapeutic strategies for residual or recurrent aneurysm (RRA) after microsurgical clipping have not been well established. The purpose of this study was to report our retreatment experiences with previously clipped aneurysms and to demonstrate retreatment strategies for these RRAs. PATIENTS AND METHODS: From 1996-2016, we treated 68 RRAs after previous clipping. Among them, 34 patients underwent microsurgical retreatment, and the other 34 underwent endovascular retreatment. Radiographic images and clinical data were reviewed retrospectively to determine the treatment efficacy, clinical outcomes, and important factors for selecting the proper treatment modality. RESULTS: The most common aneurysm location was the middle cerebral artery (50%) in the microsurgery group and the internal carotid artery (47.1%) in the endovascular surgery group (p = 0.001). In the microsurgery group, 16 (47.1%) patients had additional clipping without removal of previous clips, 17 (50.0%) had clipping with removal of previous clips, and 1 (2.9%) had bypass surgery with trapping. In the endovascular surgery group, 28 (82.4%) patients had simple coiling, 5 (14.7%) had stent-assisted coiling, and 1 (2.9%) had a flow diverter. Procedure-related complications during retreatment occurred in 4 (5.9%) patients. Complete obliteration was achieved in 51 (75.0%) patients (microsurgery group, 82.4% and endovascular surgery group, 67.6%; p = 0.002). CONCLUSIONS: In properly selected cases, treatment of RRAs could be safely performed either by microsurgery or endovascular surgery and result in a good clinical outcome with acceptable morbidity. The decision to choose the treatment modality for RRAs after clipping is not easy but should be considered to lower the risk of retreatment.

Subdural Fluid Collection After the Clipping of Unruptured Intracranial Aneurysms: Its Clinical Course and Significance.

OBJECTIVE: We evaluated the clinical course and significance of postoperative subdural fluid collection (SFC) and identified the patients who were at risk of developing postoperative chronic subdural hematoma (CSDH) after the clipping of unruptured intracranial aneurysms (UIAs). METHODS: Between January 2012 and June 2014, we retrospectively reviewed 298 patients with UIAs treated by microsurgical clipping. Among them, 257 patients were enrolled in the present study. Subdural lesions (SDLs) were defined as SFC at 1-month follow-up computed tomography (CT) and a CSDH at any time within 1 month after the clipping of UIAs. We examined the volume changes, Hounsfield unit (HU) values, and the end results of SFC in serial CT scans. RESULTS: The incidence of postoperative CSDH that needed burr hole surgery was 2.5%. Changes in SFC volume that occurred within 1 week of surgery were a risk factor for the occurrence of SDL at the 1-month follow-up CT (odds ratio 34.039; P < 0.001). The corrected average HU value of SCF (cut-off value: 11.9, with a sensitivity of 83.3% and specificity of 73.7%) on postoperative day 7 was an independent risk factor for development of a CSDH at the 1-month follow-up CT (odds ratio 19.261; P = 0.003). CONCLUSIONS: SDLs seen during 1-month follow-up may be associated with the occurrence of increased SFC volume within a week after the clipping of UIAs. The corrected average HU value of the SFC on postoperative day 7 was the only risk factor for the development of CSDHs at 1-month follow-up CT.

Endogenous Agmatine Induced by Ischemic Preconditioning Regulates Ischemic Tolerance Following Cerebral Ischemia.

Ischemic preconditioning (IP) is one of the most important endogenous mechanisms that protect the cells against ischemia-reperfusion (I/R) injury. However, the exact molecular mechanisms remain unclear. In this study, we showed that changes in the level of agmatine were correlated with ischemic tolerance. Changes in brain edema, infarct volume, level of agmatine, and expression of arginine decarboxylase (ADC) and nitric oxide synthases (NOS; inducible NOS [iNOS] and neural NOS [nNOS]) were analyzed during I/R injury with or without IP in the rat brain. After cerebral ischemia, brain edema and infarct volume were significantly reduced in the IP group. The level of agmatine was increased before and during ischemic injury and remained elevated in the early reperfusion phase in the IP group compared to the experimental control (EC) group. During IP, the level of plasma agmatine was increased in the early phase of IP, but that of liver agmatine was abruptly decreased. However, the level of agmatine was definitely increased in the ipsilateral and contralateral hemisphere of brain during the IP. IP also increased the expression of ADC-the enzyme responsible for the synthesis of endogenous agmatine-before, during, and after ischemic injury. In addition, ischemic injury increased endogenous ADC expression in the EC group. The expression of nNOS was reduced in the I/R injured brain in the IP group. These results suggest that endogenous increased agmatine may be a component of the ischemic tolerance response that is induced by IP. Agmatine may have a pivotal role in endogenous ischemic tolerance.

Ideal clipping methods for unruptured middle cerebral artery bifurcation aneurysms based on aneurysmal neck classification.

Endovascular coiling is widely used for many cerebral aneurysms; however, in cases of middle cerebral artery bifurcation (MCBIF) aneurysms, it is associated with a higher incidence of unfavorable outcomes compared to microsurgical clippings. In this retrospective study, we aimed to investigate the outcomes of microsurgical clipping for unruptured MCBIF aneurysms and determine the ideal clipping methods for different aneurysm subtypes. From January 2011 to December 2013, 203 aneurysms with saccular shape (<25 mm) were treated by an experienced neurosurgeon. Depending on the involvement of the aneurysmal thin wall, the aneurysm neck was classified as follows: subtype I, limited bifurcation; subtype II, progressed to M1 trunk; subtype III, progressed to M2 trunk; subtype IV, progressed to M1 and one M2 trunk; and subtype V, progressed to M1 and two M2 trunks. The clipping methods included simple, sliding, interlocking, or mixed approaches. Aneurysm clippings were accomplished without any morbidity in all cases, and seven cases had a minimal neck remnant. The following clipping methods were predominantly used: subtype I, simple (90.2%) and sliding (8.8%) (mean = 1.2 clips); subtype II, interlocking (51.4%), sliding (30.0%), mixed (15.7%), and simple (2.9%) (2.4 clips); subtype III, simple (57.5%) and sliding (42.5%) (1.5 clips); subtype IV, interlocking (64.3%) (2.1 clips), simple (10.7%), sliding (14.3%), and mixed (10.7%); and subtype V, interlocking (50.0%), sliding (35.7%), and mixed (14.3%) methods with multiple clips (2.8 clips). If an appropriate clipping method is selected according to the neck classification, satisfactory surgical obliteration can be achieved for unruptured MCBIF aneurysms without morbidity.

Localization and Treatment of Unruptured Paraclinoid Aneurysms: A Proton Density MRI-based Study.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of proton density magnetic resonance (PD MR) imaging for localization of paraclinoid internal carotid artery aneurysms. MATERIALS AND METHODS: From April 2014 to April 2015, 76 unruptured paraclinoid aneurysms in 66 patients were evaluated using PD MR and angiography (CT/MR angiography or digital subtraction angiography). The locations (extradural, transdural, intradural) in relation to the distal dural ring (DDR) and projection (superior, inferior/posterior, medial, lateral) of the aneurysms were assessed and compared. RESULTS: The most common location of paraclinoid aneurysms was extradural (n = 48, 63.2%), followed by intradural (n = 18, 23.7%), and transdural (n = 10, 13.2%). In the medial projection group (n = 49, 64.5%), 31 were extradural (63.3%), 5 were transdural (10.2%), and 13 were intradural (26.5%). In the inferior/posterior projection group (n = 19, 25.0%), there were 14 extradural (73.7%), 4 transdural (21.0%), and 1 intradural (5.3%). In the superior (n = 4, 5.3%)/lateral (n = 4, 5.3%) projection groups, there were 0/3 extradural (0/75.0%), 1/0 transdural (25.0/0%), and 3/1 intradural (75.0/25.0%). CONCLUSION: PD MR showed sufficient contrast difference to distinguish paraclinoid aneurysms from surrounding dural structures.

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.

Clinical Analysis of Traumatic Cerebral Pseudoaneurysms.

OBJECTIVE: Traumatic pseudoaneurysms are rare but life-threatening lesions. We investigated the patients with these lesions to clarify their clinical characteristics and therapeutic strategies and we also reviewed the literatures on the treatment principles, possible options, and outcomes. METHODS: There were a total of 8 patients who were treated with traumatic intracranial pseudoaneurysms between April 1980 and January 2009. Medical charts and the imaging studies were reviewed for analysis. The outcome was measured with modified Rankin Scale (mRS) score at 6 months after treatment. RESULTS: All 8 patients were male and the mean age was 25 years old. Six of those were located at the cavernous segment of the internal carotid artery (ICA) and the other 2 was located at the M2 segment of middle cerebral artery. The causes of trauma were car accidents in 6, penetrating injury through the orbit in 1, and slip down injury in 1 patient. Massive epistaxis or hematemesis occurred in all patients with a pseudoaneurysm at the cavernous and ophthalmic segment of the ICA. All 6 patients of the cavernous and ophthalmic ICA group showed favorable outcome of mRS 0 to 1. The outcome of patients with middle cerebral artery pseudoaneurysm was mRS 2 to 3. CONCLUSION: Upon prompt diagnosis and proper treatment planning, it is possible to achieve favorable outcome in these patients. Lesions located at the cavernous segment of the ICA favored endovascular treatment while those at the middle cerebral artery favored surgical treatment.

Relationship between Two Types of Coil Packing Densities Relative to Aneurysm Size.

BACKGROUND AND PURPOSE: Coil packing density (PD) can be calculated via a formula (PDF ) or software (PDS ). Two types of PD can be different from each other for same aneurysm. This study aimed to evaluate the interobserver agreement and relationships between the 2 types of PD relative to aneurysm size. METHODS: Consecutive 420 saccular aneurysms were treated with coiling. PD (PDF , [coil volume]/[volume calculated by formula] and PDS, [coil volume]/[volume measured by software]) was calculated and prospectively recorded. Interobserver agreement was evaluated between PDF and PDS . Additionally, the relationships between PDF and PDS relative to aneurysm size were subsequently analyzed. RESULTS: Interobserver agreement for PDF and PDS was excellent (Intraclass correlation coefficient, PDF ; 0.967 and PDS ; 0.998). The ratio of PDF and PDS was greater for smaller aneurysms and converged toward 1.0 as the maximum dimension (DM ) of aneurysm increased. Compared with PDS , PDF was overestimated by a mean of 28% for DM < 5 mm, by 17% for 5 mm ≤ DM < 10 mm, and by 9% for DM ≥ 10 mm (P < 0.01). CONCLUSIONS: Interobserver agreement for PDF and PDS was excellent. However, PDF was overestimated in smaller aneurysms and converged to PDS as aneurysm size increased.

The role of endovascular treatment for ruptured distal anterior cerebral artery aneurysms: comparison with microsurgical clipping.

BACKGROUND AND PURPOSE: 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. METHODS: Eighty-four consecutive patients (M:F = 36:48; mean 53.8 years) with ruptured DACA aneurysms were treated by either clipping (n = 46, 54.8%) or coiling (n = 38, 45.2%). The clinical outcomes and procedure-related complications were evaluated and compared between the two groups. RESULTS: Procedure-related complications tend to occur more frequently in the clipping (n = 6, 13.0%) than coiling group (n = 1, 2.6%) (P = .121). At discharge, 51 patients (60.7%) had favorable outcomes (Glasgow outcome scale [GOS], 4 or 5). There was no significant difference between the two groups in favorable outcome (63.2% vs. 58.7%; P = .677). Hunt and Hess (HH) grade (P < .001; 95% CI, 3.354-29.609) and treatment modality (P = .044; 95% CI, 1.039-16.325) were independent risk factors for poor outcome (GOS, 1-3). CONCLUSIONS: Coiling was more favorable to clipping in clinical outcomes and incidence of treatment-related complications for ruptured 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 Lawton's 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+.

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

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.

Long-term clinical and angiographic outcomes of wrap-clipping strategies for unclippable cerebral aneurysms.

PURPOSE: To evaluate the efficacy and stability of the wrap-clipping methods as a reconstructive strategy in the treatment of unclippable cerebral aneurysms. MATERIALS AND METHODS: Twenty four patients who had undergone wrap-clipping microsurgery were retrospectively reviewed. Type and morphology of the treated aneurysm, utilized technique for wrap-clip procedure, and clinical outcome with angiographic results at their last follow-up were evaluated. RESULTS: Of 24 patients, eleven patients had internal carotid artery (ICA) blister-like aneurysms, three had dissecting type aneurysms, and ten had fusiform aneurysms. The follow-up period for the late clinical and angiographic results ranged from 10 to 75 months (mean 35 months). Wrap-clipping was performed in eleven, wrap-holding clipping was in ten, and combination of wrap-clip and wrap-holding clip was in three cases. At the last angiographic follow-up study, twelve aneurysms (50%) were found to have completely healed, and nine aneurysms (38%) were at least stable. However, wrap-holding clip for the elongated blister type of ICA aneurysm was found failed, leading to fatal rebleeding in one case, and two cases of combination of wrap-clip-wrap-holding clip revealed delayed branch occlusion and marked regrowing, respectively. CONCLUSION: Wrap-clipping strategy could be an easy and safe alternative for unclippable aneurysms. The wrapped aneurysm mostly disappeared, or at least remained stationary, after a long-term period. However, surgeons should be aware of that the wrapped aneurysm might become worse. Therefore, follow-up surveillance for an extended period should be mandatory.

Outcomes of multidisciplinary treatment for posterior cerebral artery aneurysms.

OBJECTIVE: Posterior cerebral artery (PCA) aneurysms are rare and often challenging to manage. Since Drake's 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.

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.