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.ope

Effect of premedication method and drug resistance of antiplatelet agent on periprocedural thromboembolic events during coil embolization of an unruptured intracranial aneurysm

OBJECTIVE: A retrospective review of premedication method and drug resistance of aspirin and clopidogrel in association with thromboembolic events during and after coil embolization of an unruptured intracranial aneurysm was conducted. METHODS: Our premedication policy for coil embolization of an unruptured intracranial aneurysm has changed from administration of the loading dose before the procedure (i.e. loading group) to repeated administration of the maintenance dose for several days (i.e. preparation group). The loading group (27 patients with 29 aneurysms) and the preparation group (30 patients with 35 aneurysms) were compared for identification of the effect of premedication method on periprocedural thromboembolic events. The results of drug response assays of the preparation group were analyzed with respect to periprocedural thromboembolic events. RESULTS: No statistically significant difference in incidence of thromboembolic events was observed between the loading group and the preparation group. Analysis of the results of the drug response assay showed high prevalence (56.7%, 73.3%) of clopidogrel resistance and relatively low prevalence (6.7%) of aspirin resistance. Patients who had thromboembolic events tended to have lower responsiveness to both aspirin and clopidogrel than patients without it. CONCLUSION: The method of antiplatelet premedication does not affect the rate of periprocedural thromboembolic events in coil embolization for treatment of an unruptured intracranial aneurysm. Nevertheless, considering the high prevalence of drug resistance, it is reasonable to premedicate antiplatelet agents in the preparation method for the drug response assay. Use of a higher dose of aspirin and clopidogrel or addition of an alternative drug (cilostazol or triflusal) can be applied against antiplatelet agent resistance. However, because the hemorrhagic risk associated with this supplementary use of antiplatelet agent has not been well-documented, the hemorrhagic risk and the preventive benefit must be weighed.ope

Risk Factors of Seizures Associated with the Management of Ruptured Cerebral Aneurysms

Objective : This study was designed to to analyze the associated risk factors of seizure after aneurysmal subarachnoid hemorrhage(SAH) for providing guidelines of prophylactic antiepileptic drug administration. Method : We retrospectively reviewed the programmed clinical database and radiographic findings of the patients with aneurysmal SAH who were treated from March 1996 to August 2004 and followed up for more than one year. Result : A total of 512 patients were enrolled. 20 patients (3.9%) presented with seizures. Aneurysm location and size were not associated with seizures. The incidence of seizure was significantly different in the Hunt & Hess Grade IV patients (8.6%) and V patients (23.1%). Fisher Grade IV was associated with a significantly higher risk of the seizure (12.2%). The incidence of seizure was higher in patients with hydrocephalus (6.7%), intracerebral hematoma (8.8%), and decompressive lobectomy (14.3%). Conclusion : The overall incidence of seizures was 3.9%. Risk factors of seizures were poor clinical grade (Hunt &Hess Grade IV and V), higher Fisher Grade (IV), hydrocephalus, intracerebral hematoma, and decompressive lobectomy.ope

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.ope

Clinical Analysis of Patients with Ruptured Cerebral Aneurysms associated with Polycystic Kidney Disease

Objective : This study is to define the clinical characteristics and formulate the management strategies of the patients with ruptured cerebral aneurysms associated with polycystic kidney diseases (PKD). Methods : During the past 30 years, among of 3,013 patients who were treated with intracranial aneurysms, 7 patients had ruptured cerebral aneurysms associated with PKD. The authors retrospectively reviewed the database and imaging studies of such patients as sources for identification and analysis. Results : All 7 patients presented with subarachnoid hemorrhage (SAH). One patient showed Hunt and Hess grade I, 4 of grade II, and 2 of grade III. Six patients showed Fisher group II and 1 patient of group III. Four aneurysms were located at anterior cerebral artery, 2 at middle cerebral artery, and 1 at internal carotid artery. Five patients had small aneurysms and the remaining 2 had large (diameter ≥ 10 mm) aneurysms. All aneurysms were in saccular shape. Two of the 7 patients (28.6%) had multiple aneurysms. One patient suffered delayed ischemic neurological deficit. All patients were treated by microsurgery and showed favorable outcome (good : 7). Conclusions : The patients harboring PKD had high probability of hypertension. So, intact aneurysms in those patients were exposed to higher rate of being ruptured. Surgery was necessary for ruptured lesions, as well as unruptured lesions which size was increased at follow up imaging study. Multimodality management approach with nephrologist and neuroradiologist are very necessary. The ultimate management outcome was satisfactory.ope

A Clinical Experience of 72 Patients with Aneurysms arising from the Anomalous Cerebral Artery

Objective : Aneurysm rupture at the anomalous artery is rare but inadvertent clip occlusion may cause critical complications. The aim of this study was to examine the frequency of the cerebral aneurysms associate with the vascular anomalies and the surgical considerations. Methods : We analyzed 2802 patients with aneurysms treated from September, 1976 to July, 2004. A diagnosis of 'anomalous artery ' was made on the basis of angiographic or surgical findings in 72 patients. Surgery was carried out in 68 patients and 4 were treated with endovascular methods. Results : Fenestrated anterior communicating artery (A-com.) was the most common anomaly (33cases, 45. 8%), 24 cases of 3rd A2 (33.3%), and 9 cases of azygous A2 (12.5%). fenestrated M1 was 1 cases (1.4%) and the one duplicated MCA (1. 4%). 3 cases of fenestrated basilar artery (4.2%) and one primitive trigeminal artery aneurysm (1.4%) were treated with GDC. In our series vascular anomalies were found in 6% of the all Acom aneurysm cases. Conclusion : It is often difficult to recognize a fenestration or other anomalies of cerebral arteries prior to surgery, even with precise angiographic analysis. The A-com artery complex is one of most frequent sites of vascular anomalies. Preoperative and intraoperative concerns is required to avoid inadvertent occlusion of parent artery or misplacement of clip, which may result in critical complications or poor outcomes.ope

Clinical characteristics of pediatric Cerebral Aneurysms

Objective : The aim of this study was to define the clinical characteristics of pediatric cerebral aneurysms. Methods : During the past 30 years, among a total of 3, 330 patients treated for cerebral aneurysms, 12 patients were under the age of 18. The authors reviewed the database and imaging studies as sources for identification and analysis. Results : Seven patients were male and 5 were female. The mean age was 12.9 years old (range: 3~18). Nine patients had ruptured lesions and the remaining 3 had unruptured lesions. Four patients presented with a subarachnoid hemorrhage, and the other 5 patients presented with an intracerebral hemorrhage (ICH). Five aneurysms were located at the posterior cerebral artery or vertebrobasilar artery, 4 at the middle cerebral artery, and 3 at the internal carotid artery, respectively. The giant aneurysm was observed in 2 (18%) patients. Eleven aneurysms were saccular, and 1 was serpentine in shape. No patient had multiple aneurysms. Rebleeding was observed in 3 cases (33%). No child suffered from clinical vasospasm. All but one patient showed a favorable outcome (good: 11, dead: 1). Conclusions : Pediatric cerebral aneurysms in this study showed a male predominance, a high incidence of presentation with ICH, a location on the distal circulation of the major arteries or on the posterior circulation, and a large or giant aneurysm, high rebleeding rate and a low incidence of vasospasm. The overall clinical outcome was excellent in 91.7% in this study. With the knowledge of these features, aneurysmal obliteration and active brain resuscitation can improve the clinical outcome and prognosis.ope

Therapeutic Strategies of Middle CerebralArteryM1 Trunk Aneur

Objective : This study was designed to define the clinical characteristics and to establish the therapeutic strategies for treating aneurysms located at the M1 trunk of the middle cerebral artery (MCA). Methods : During the past 30 years from September 1976 to December 2006, 47 (6.2% of the 755 treated MCA aneurysms) consecutive patients with M1 aneurysms were treated at our institute. We retrospectively reviewed the database and imaging studies of these 47 patients for analysis. Nine patients (19.1%) were male and 38 (80.9%) patients were female. The mean age was 51.7 years (range: 381 years). Thirty-three (70.2%) patients had ruptured lesions: 3 patients were Hunt and Hess Grade I, 16 patients were Grade II, 7 patients-were Grade III, 4 patients were Grade IV and 3 patients were Grade V. Intracerebral hemorrhage was identified in 9 patients on the initial computed tomograph images. Fourteen patients had unruptured lesions. The diameters of the aneurysms were 25 mm in 2 patients. The mean diameter of the aneurysms was 5.1mm (range: 2.029.0mm). Eleven patients (23.4%) had multiple aneurysms. The repair methods for the aneurysms were microsurgery in 42 (89.4%) patients (clipping: 36, wrapping: 6, aneurysm resection and suture: 1) and coiling in 5 patients. The mean posttreatment follow up period was 45.5 months. The clinical outcome was assessed using the Glasgow Outcome Scale. The therapeutic results of lesion repair, the long-term clinical outcome and the causes of an unfavorable outcome were also analyzed. Results : The overall outcome was favorable in 39 (82.9%) patients (excellent: 32, good: 7) and unfavorable in 8 (17.1%) (fair: 6, poor: 1, dead: 1) patients. The major causes of an unfavorable outcome were the initial insults. Seven patients suffered from a delayed ischemic deficit, and 3 of them were left with a permanent deficit. Surgery-related complications occurred in 8 patients (cerebral infarction: 6, intracerebral hemorrhage: 2) and 3 were left with a permanent deficit. The angiographic results of coiling were complete packing in 3 (60%), a neck remnant in 1 (20%) and incomplete packing for 1 (20%). There was no coiling-related complication. Conclusion : In our series, M1 aneurysms had characteristics of a female predominance, the patients more often presented with intracerebral hemorrhage, and a high risk of postoperative ischemic complication. Due to the small size, wide neck and location at the branching site, M1 aneurysms can be treated with surgery rather than coiling, but surgeons should be careful for injury of the branching vessels like the lateral lenticulostriate artery and they must be prepared for various inevitable situations that occur during surgery.ope

Surgical Complications of Cerebral Arteriovenous Malformation: A Retrospective Analysis of 297 Consecutive Cases

To analyze the complications following surgical resection of cerebral arteriovenous malformations (AVMs) and to improve the surgical outcomes, we reviewed 297 consecutive patients who had undergone surgical excision of AVM at Yonsei University between June 1975 and July 2004. The patients' ages ranged from 2 to 68 with a mean age of 29 years. The series included 182 males (61.3%) and 115 females (38.5%). The most common presenting symptom was hemorrhage (228 patients, 76.8%). And others were seizure (45 patients, 15.2%), hemorrhage with seizure (12 patients, 4.1%), focal deficit (3 patients, 1.0%), headache (4 patients, 1.3%) and incidental (5 patients, 1.6%). The locations of AVMs were cerebral convexity (220 patients, 74%；46 frontal, 68 parietal, 77 temporal, 29 occipital), callosal (28 patients, 9.4%), sylvian (11 patients, 3.7%), rolandic (8 patients, 2.7%), basal ganglia and thalamus (11patients, 3.7%), cerebellum (18 patients, 6.1%) and one patient had brain stem lesion (0.3%). Postoperative rebleeding and the incomplete excision (12 and 9 patients each) were the major surgical complications, followed by postoperative epilepsy (5 patients), normal perfusion pressure breakthrough (3 patients), and infection (2 patients). The outcome was classified into good for the patients who returned to their previous jobs with or without neurological deficits, fair for the patients who were unable to return to work but performed daily activities independently with minor deficits, and poor for the patients who were performing dependent daily activities with major deficits. The average follow-up period was 4.2 years. The overall outcome of surgery was considered good in 233 patients (75.0%), fair in 51 patients (17.2%), poor in 15 patients (5.1%) and 8 patients (2.7%) were died. The Spetzler-Martin grading system correlated well with the difficulty of surgery. No morbidity resulted from resection of Grade I AVMs；the percentage with unfavorable outcome was 8.1% in Grade II, 9.6% in Grade III, and 28.6% for those with Grade IV. Initial insult (14 patients) and rebleeding (4 patients) were the major causes of unfavorable outcome. Prevention of postoperative hemorrhage following meticulous hemostasis and complete excision and prevention of hemodynamic complications would result in a favorable outcome after surgery for cerebral AVM.ope

Cerebral Arteriovenous Malformations in Pediatric Age : A Clinical Analysis of 164 Consecutive Cases

Objective : This study was designed to understand the clinical characteristics and to establish therapeutic options for arteriovenous malformations (AVM) in a pediatric age (1~18 year old) group. Methods : We reviewed programmed clinical data, patients' medical records and imaging studies of the 164 pediatric AVM patients who were managed at Yonsei University Medical Center from 1975 to 2004. Clinical presentation, location, Spetzler-Marin grade, treatment modality and outcomes were analyzed. Results : Ninety-one patients (55.5%) were male and seventy-three (44.5%) were female. The most common presenting symptom was hemorrhage (119 patients, 72.6%). In others the symptoms were seizure (26 patients, 15.9%), hemorrhage with seizure (6 patients, 3.6%), focal deficit (4 patients, 2.4%), headache (8 patients, 4.9%) and incidental (1 patients, 0.6%). The locations of AVMs were cerebral convexity (110 patients, 67.1%; 21 frontal, 40 parietal, 23 temporal, 23 occipital), basal ganglia and thalamus (24 patients, 14.6%), corpus callosum (12 patients, 7.3%), sylvian (3 patients, 1.8%), cerebellum (13 patients, 7.9%) and two patients had brain stem lesions (1.2%). According to the Spetzler-Martin grading system, at admission grade II and III AVMs were the most common lesions in our series (43.9% and 33.5%, respectively). The patients were treated with microsurgery in 70 patients (42.7%), radiosurgery in 87 patients, (53.0%), combined treatment in 5 patients (3.1%) and embolization in only 2 patients (1.2%). The average follow-up period was 4. 8 years and the overall outcome was considered good in 139 patients (84.8%), fair in 18 patients (11.0%), and poor in 4 patients (2.4%), with 3 patients having died (1.8%). The causes of unfavorable outcomes were initial insult (4 patients), radiation necrosis (1 patient), bleeding during the latent interval (1 patient) and systemic complication (1 patient). Conclusion : Hemorrhagic presentation and deep brain (thalamus and ganglia) lesions were more common in the pediatric patients compared to adult patients. The treatment of choice for hemorrhagic pediatric AVMs is surgical excision, even for deep seated or eloquent area lesions. Radiosurgery is recommended especially for the non-hemorrhagic lesions, particularly in deep seated or eloquent area lesions. Regular imaging studies are necessary for detection of AVM regrowth, and signs of hemorrhage should be monitored during the latent period.ope