Sung Don Kang

Recanalization of Completely Thrombosed Non-Giant Saccular Aneurysm Mimicking as De Novo Aneurysm

Partial thrombosis of giant aneurysms is not uncommon however, complete angiographic occlusion occurs less frequently. In the case of non-giant aneurysms, complete thrombosis and recanalization has been rarely reported. A 31-year-old man presented to the emergency department with sudden bursting headache. Brain computed tomography (CT) revealed diffuse subarachnoid hemorrhage on the left side. Both CT angiography (CTA) and digital subtraction angiography showed suspicion of small left anterior choroidal artery aneurysm. We performed surgical exploration. In the operation field, anterior choroidal artery aneurysm of 2 × 2 mm with broad neck and friable appearance was observed. Because we could not clip without sacrificing the anterior choroidal artery, we performed wrapping only. Follow up CTA after 7 months demonstrated 4 mm right internal carotid artery bifurcation aneurysm. The patient underwent aneurismal neck clipping. During the operation, 9 × 13 mm sized thrombosed aneurysm was detected and completely clipped. We initially thought this aneurysm to be a de novo aneurysm however, it was an aneurysm that had recanalized from a completely thrombosed aneurysm. This case report provides an insight into the potential for complete thrombosis and recanalization of non-giant aneurysms.

Triptolide Inhibits the Proliferation of Immortalized HT22 Hippocampal Cells Via Persistent Activation of Extracellular Signal-Regulated Kinase-1/2 by Down-Regulating Mitogen-Activated Protein Kinase Phosphatase-1 Expression

OBJECTIVE Triptolide (TP) has been reported to suppress the expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1), of which main function is to inactivate the extracellular signal-regulated kinase-1/2 (ERK-1/2), the p38 MAPK and the c-Jun N-terminal kinase-1/2 (JNK-1/2), and to exert antiproliferative and pro-apoptotic activities. However, the mechanisms underlying antiproliferative and pro-apoptotic activities of TP are not fully understood. The purpose of this study was to examine whether the down-regulation of MKP-1 expression by TP would account for antiproliferative activity of TP in immortalized HT22 hippocampal cells. METHODS MKP-1 expression and MAPK phosphorylation were analyzed by Western blot. Cell proliferation was assessed by (3)H-thymidine incorporation. Small interfering RNA (siRNA) against MKP-1, vanadate (a phosphatase inhibitor), U0126 (a specific inhibitor for ERK-1/2), SB203580 (a specific inhibitor for p38 MAPK), and SP600125 (a specific inhibitor for JNK-1/2) were employed to evaluate a possible mechanism of antiproliferative action of TP. RESULTS At its non-cytotoxic dose, TP suppressed MKP-1 expression, reduced cell growth, and induced persistent ERK-1/2 activation. Similar growth inhibition and ERK-1/2 activation were observed when MKP-1 expression was blocked by MKP-1 siRNA and its activity was inhibited by vanadate. The antiproliferative effects of TP, MKP-1 siRNA, and vanadate were significantly abolished by U0126, but not by SB203580 or SP600125. CONCLUSION Our findings suggest that TP inhibits the growth of immortalized HT22 hippocampal cells via persistent ERK-1/2 activation by suppressing MKP-1 expression. Additionally, this study provides evidence supporting that MKP-1 may play an important role in regulation of neuronal cell growth.

Clinical Practice Guidelines for the Medical and Surgical Management of Primary Intracerebral Hemorrhage in Korea

The purpose of this clinical practice guideline (CPG) is to provide current and comprehensive recommendations for the medical and surgical management of primary intracerebral hemorrhage (ICH). Since the release of the first Korean CPGs for stroke, evidence has been accumulated in the management of ICH, such as intracranial pressure control and minimally invasive surgery, and it needs to be reflected in the updated version. The Quality Control Committee at the Korean Society of cerebrovascular Surgeons and the Writing Group at the Clinical Research Center for Stroke (CRCS) systematically reviewed relevant literature and major published guidelines between June 2007 and June 2013. Based on the published evidence, recommendations were synthesized, and the level of evidence and the grade of the recommendation were determined using the methods adapted from CRCS. A draft guideline was scrutinized by expert peer reviewers and also discussed at an expert consensus meeting until final agreement was achieved. CPGs based on scientific evidence are presented for the medical and surgical management of patients presenting with primary ICH. This CPG describes the current pertinent recommendations and suggests Korean recommendations for the medical and surgical management of a patient with primary ICH.

Clinical and Angiographic Outcomes of Wingspan Stent Placement for Treatment of Symptomatic Intracranial Stenosis: Single Center Experience with 19 Cases

Objective The limitations of medical management of symptomatic intracranial arterial stenosis (ICS) have prompted development of new strategies, including endovascular treatment. However, stenting of symptomatic ICS remains investigational. Here, we have reported and analyzed a series of 19 endovascular procedures involving placement of a Wingspan stent. Methods We conducted a retrospective review of a series of ICS in which patients were treated with percutaneous transarterial balloon angioplasty and stent placement (PTAS). Patients included in the study were diagnosed as symptomatic ICS between May 2010 and September 2011. Results Nineteen patients (median age, 65 years; 12 males, seven women) were treated with the Wingspan stent system for symptomatic ICS ranging from 50% to 99%. The technical success rate was 100%. The location of ICS included the internal carotid (n = 5; 1 petrous, 3 cavernous, and 1 clinoid segments), vertebral (n = 1; V4 segment), basilar (n = 1), and middle cerebral (n = 12; 9 M1, 3 M2) arteries. There was no occurrence of procedure-related mortality. Periprocedural morbidity occurred in two cases (10.5%), including carotid-cavernous fistula (n = 1) and subarachnoid hemorrhage (n = 1). No ipsilateral stroke was recorded beyond 30 days during a mean follow-up period of 13.2 months (range 9-19 months). Restenosis (> 50%) was observed in one patient (6.3%), who was asymptomatic, on follow-up imaging. Conclusion Wingspan stent for symptomatic ICS can be performed with a high rate of technical success and acceptable periprocedural morbidity rates. Our initial experience indicates that this procedure represents a viable treatment option for this patient population.

Updated Korean Clinical Practice Guidelines on Decompressive Surgery for Malignant Middle Cerebral Artery Territory Infarction

Clinical practice guidelines (CPGs), which provide systemic reviews of accumulated scientific evidence, are used by clinicians to choose optimal treatment modalities. In Korea, the Clinical Research Center for Stroke (CRCS) published the first version of its CPGs for stroke in October 2009; it was based on articles that had been reported before June 2007 [1]. Since then, major trials of decompressive surgery for malignant middle cerebral artery (MCA) have been published, and the CRCS and Korean Society of Cerebrovascular Surgeons (KSCVS) therefore decided to revise the CPGs to reflect this new evidence. To select source papers for the revision, we searched Pubmed for English-language articles published between July 2007 and May 2014 that contained the word “stroke,” plus any one of the following terms or phrases: “malignant MCA infarction,” “hemicraniectomy,” and “decompressive surgery.” We retrieved 122 articles with the key words “stroke” and “malignant MCA infarction,” 136 articles with “stroke” and “hemicraniectomy,” and 225 articles with “stroke” and “decompressive surgery.” We then narrowed this pool of articles down by limiting the search to prospective, randomized clinical trials, pooled analyses, and meta-analyses and found five such articles that were published during this period. We reviewed a total of five randomized, clinical trials [2-6], one pooled analysis [7], and one meta-analysis [4], including three studies [2,3,7] that were mentioned in the first edition. The revised versions of the CPGs for decompressive surgery from the European Stroke Organization (ESO) (May 2008) [8], the Scottish Intercollegiate Guidelines Network (December 2008) [9], the National Clinical Guidelines for Stroke of the Royal College of Physicians (July 2008) [10], and the American Heart Association (AHA)/American Stroke Association (ASA) guidelines (published, respectively, in 2013 and 2014) [11,12] were also considered. After we reviewed these articles and described new evidence in guidelines, each piece of evidence and recommendation was given a strength based on a definition of evidence level and recommendation grade used in the KSCVS and the CRCS guidelines (Table 1). Table 1. Evidence levels and recommendation grades used by the Korean Society of Cerebrovascular Surgeons and the Clinical Research Center for Stroke Our purpose in updating the CPGs is to incorporate the new evidence and to help physicians, patients with malignant MCA infarction, and their caregivers make decision regarding decompressive hemicraniectomy. The recommendations were peer reviewed by steering committee members of the CRCS. A consensus meeting convening experts from the Korean Stroke Society and the KSCVS was also held on January [13], 2014, to determine the level of evidence and grade of recommendation.

Emergent Clipping without Prophylactic Decompressive Craniectomy in Patients with a Large Aneurysmal Intracerebral Hematoma

OBJECTIVE Many vascular neurosurgeons tend to remove bone flap in patients with large aneurysmal intracerebral hematomas (ICH). However, relatively little work has been done regarding the effectiveness of prophylactic decompressive craniectomy in a patient with a large aneurysmal ICH. METHODS Large ICH was defined as hematoma when its volume exceeded 25 mL, ipsilateral to aneurysms. The patients were divided into two groups; aneurysmal subarachnoid hemorrhage (SAH) associated with large ICH, January, 1994 - December, 1999 (Group A, 41 patients), aneurysmal SAH associated with large ICH, January, 2000 - May, 2005 (Group B, 27 patients). Demographic and clinical variables including age, sex, hypertension, vasospasm, rebleeding, Hunt-Hess grade, aneurysm location, aneurysm size, and outcome were compared between two groups, and also compared between craniotomy and craniectomy patients in Group A. RESULTS In Group A, 21 of 41 patients underwent prophylactic decompressive craniectomy. In Group B, only two patients underwent craniectomy. Surgical outcome in Group A (good 23, poor 18) was statistically not different from Group B (good 15, poor 12). Surgical outcomes between craniectomy (good 12, poor 9) and craniotomy cases (good 11, poor 9) in Group A were also comparable. CONCLUSION We recommend that a craniotomy can be carried out safely without prophylactic craniectomy in patients with a large aneurysmal ICH if intracranial pressure is controllable with hematoma evacuation.

Clipping of the Anterior Communicating Artery Aneurysm without Sylvian Fissure Dissection.

OBJECTIVE The focus of aneurysm surgery is eliminating unnecessary operative manipulations and preparing the surgeon for any crises that might arise. With this concept in mind, we have tried resection of the gyrus rectus without routine sylvian fissure dissection in selected patients with anterior communicating artery (ACom) aneurysms, and compared these results with those from the conventional transsylvian approach. METHODS This retrospective study included 231 surgically treated patients with ACom aneurysms from March, 1997 to May, 2005. The patients were divided into two groups : Group A (96 with sylvian fissure dissection, March, 1997-December, 2000) and Group B (135 without sylvian fissure dissection, January, 2001-May, 2005). Overall surgical outcomes were compared, and operative times have been prospectively recorded since January, 04 to evaluate how this maneuver affected the length of surgical procedures. RESULTS All aneurysms were satisfactorily clipped, and there was no evidence of increased number of procedure-related retraction injuries in group B. Overall outcome was good in 186 (80.5%); 76 (79.2%) in group A, and 110 (81.5%) in group B (x(2) test, p=0.79). In good clinical grade of group A, good outcome was observed in 60 patients (89.6%) and in group B, 97 patients (94.2%) (Fishers exact test, p=0.38) (Fig. 2). CONCLUSION In this study, eliminating the step of sylvian fissure dissection by gentle lateral basal-frontal retraction to the side of the sylvian fissure did not increase morbidity and mortality. However, we do not intend to modify the standard approach to the ACom aneurysm that is familiar to and has been mastered by many others. Rather, we report our experience on the basis of our anatomic understanding of the technique and its results.

Ophthalmic artery occlusion after carotid revascularization.

Distal embolization resulting from carotid angioplasty and stenting (CAS) occurs mainly in the cerebral hemisphere. We report a case of ophthalmic artery occlusion after carotid revascularization. A 75-year old man received emergency CAS for cervical internal carotid artery occlusion. Two months later, the patient was readmitted for decreased visual acuity. We found ophthalmic artery occlusion that was not noticed soon after CAS. Although ophthalmic artery occlusion after CAS is rare, endovascular neurosurgeons should be aware of this potential complication.