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O-Ki Kwon

Publications and source records attributed to O-Ki Kwon.

At least 19 recordsLinked to original sources
PubMed2007

CT angiography demonstration of the development of intraventricular hemorrhage during aneurysm rupture.

The authors present the 3D reconstructed CT angiography image of extravasation from a rebleeding aneurysm. Direct hemorrhage of a bleeding aneurysm into the lateral ventricle was detected by CT angiography. This image clearly visualized that extravasated contrast medium spurting from a rupturing anterior communicating artery aneurysm, penetrated the ventricle wall and passed through the lateral ventricle to reach the temporal horn. This case provides a real-time demonstration of the way how an intraventricular hemorrhage develops during rupture of an anterior communicating artery aneurysm.

Aged↗
PubMed2006

Repeat endovascular treatment in post-embolization recurrent intracranial aneurysms.

OBJECTIVE: The purpose of this study was to describe clinical situations requiring repeat embolization in patients previously treated by endovascular coil embolization for intracranial aneurysms, and to report on our experiences of repeat embolization (RE). METHODS: A total of 466 patients harboring 522 intracranial aneurysms were treated by endovascular coil embolization at our institution during the period between December 1992 and August 2004. We studied 32 patients who underwent repeat coil embolization (RE) owing to recanalization or aneurysm recurrence. Radiological and clinical data were reviewed to determine the reasons, results, and technical problems of RE. RESULTS: Thirty-nine sessions of RE were performed in 32 patients; four patients underwent RE twice and another patient three times. The major reason for RE was asymptomatic aneurysmal recanalization owing to coil compaction and/or loosening. The time interval between RE and the previous embolization was 12 months or less in 27 sessions. Complete or near complete occlusion of the aneurysm was achieved in all cases without procedure-related morbidity or mortality. Radiolucent gaps between the coil masses were observed in 17 cases. CONCLUSION: RE is a safe and effective treatment option in cases of recanalized or recurrent aneurysms. Close follow-up evaluation is essential in patients with intracranial aneurysms after coil embolization.

Adult↗
PubMed2005

Fiber tracking by diffusion tensor imaging in corticospinal tract stroke: Topographical correlation with clinical symptoms.

Fiber tracking of the white matter using diffusion tensor imaging is a new imaging technique to visualize the integrity of the white matter. This study investigated the capability of this technique to localize the lacunar infarctions, particularly with respect to the body parts affected, by correlating the location of the lesion with the clinical symptoms topographically. Twenty-seven patients with capsular and pericapsular small acute infarctions underwent diffusion tensor imaging and subsequent fiber tracking of the corticospinal tract (CST). According to the lesion topography with regard to the CST, the infarctions were classified into four types: (1) the anterior type (n = 9) involving the anterior part of the CST, (2) the central type (n = 9) involving the middle or whole part of the CST, (3) the posterior type (n = 5) involving the posterior part of the CST and (4) the intact type (n = 4) not involving the CST. Motor weakness of the face, upper extremities and lower extremities was found at 100%, 67% and 44%, respectively in the anterior type, at 89%, 100% and 89%, respectively in the central type and at 20%, 80% and 100%, respectively in the posterior type. The intact type was not associated with motor weakness. In conclusion, the fiber tracking technique of the CST enables the specific localization of capsular and pericapsular infarctions with regard to the body parts affected. These results also confirm the topographical accuracy of the fiber tracking of the CST.

Aged↗
PubMed2005

Moyamoya disease associated with Graves disease: special considerations regarding clinical significance and management.

OBJECT: In moyamoya disease (MMD), ischemic events are usually precipitated by activities associated with hyperventilation or physical strain. The authors report on four patients with a rare combination of Graves disease-associated thyrotoxicosis and MMD, whose cerebrovascular ischemic events occurred while in a thyrotoxic state. The clinical correlation between MMD and Graves' thyrotoxicosis, and outcome after surgical intervention are described. METHODS: Four young women, ages 22 to 25 years, presented with profound cerebrovascular ischemic accidents. They had clinical and radiological features consistent with the diagnosis of MMD and were in the active thyrotoxic state of Graves disease. To prevent a future ischemic event, patients underwent superficial temporal artery-middle cerebral artery anastomosis combined with encephalomyosynangiosis or encephaloduroarteriosynangiosis after normalization of their hormonal conditions. All patients have been neurologically stable since revascularization procedures and lead a normal daily life. In patients with MMD, cerebrovascular ischemic events may be precipitated by thyrotoxicosis. One possible pathomechanism of cerebrovascular ischemic aggravation in the thyrotoxic state may be a hemodynamic compromise induced by an excessive increase in the cerebral metabolism and oxygen demand over the compensation of the cerebral blood flow deficit through collateral supply in MMD. CONCLUSIONS: Surgical revascularization after optimal control of thyrotoxicosis is thought to be an appropriate treatment in patients with MMD concurrent with Graves disease for the prevention of further ischemic events, especially in those with impaired cerebral perfusion and cerebral ischemic symptoms.

Adult↗
PubMed2005

Evaluation of the lenticulostriate arteries with rotational angiography and 3D reconstruction.

BACKGROUND AND PURPOSE: Anatomic evaluation of the lenticulostriate arteries (LSAs) is important, especially in cases of surgical or endovascular treatment, but biplanar angiography provides limited information. We analyzed the LSAs with rotational angiography (RA) and 3D reconstruction and compared the findings with those of previous autopsy studies. METHODS: We retrospectively reviewed the LSAs on 3D reconstructed RA images (200 sides in 159 cases) to analyze their origin, course, and supplying territories. The angiographic configurations of the LSAs were classified by using the scheme devised by Yasargil. RESULTS: LSAs from the anterior cerebral artery were demonstrated on 140 sides (70%). They originated from the A1 segment in 59 sides, from the A1-A2 junction on 41 sides, and from the A2 segment on 35 sides. They arose as a single trunk and ended as the most medial and anterior perforators in most cases. Arteries from the middle cerebral artery (MCA) were demonstrated on 190 sides (95%). They originated from the M1 segment on 131 sides, from the MCA bifurcation on 26 sides, and from the M2 segment on 33 sides; notably, all LSAs arising from the M2 segment originated from the superior division. In terms of configuration, we identified four major and 11 minor types. The most frequent LSA type was the combination of medial and lateral distal striate arteries, which comprised 53 sides (28%). CONCLUSION: Analysis of LSAs with RA and 3D reconstructed images may provide useful information in patients with cerebrovascular diseases, especially before surgical and endovascular treatment.

Adolescent↗
PubMed2005

Endovascular treatment of wide-necked aneurysms by using two microcatheters: techniques and outcomes in 25 patients.

BACKGROUND AND PURPOSE: The endovascular occlusion of aneurysms with unfavorable configurations such as a broad neck and an important branch from the fundus remains a technical challenge. The purpose of this study was to evaluate the radiologic and clinical results of complicated aneurysm treatment by using two microcatheters. METHODS: Twenty-five aneurysms in 25 patients were treated by using two microcatheters, from August 2001 to February 2004. Fourteen patients presented with a subarachnoid hemorrhage (SAH) and 11 had unruptured aneurysms. The aneurysms were of the basilar top (7), middle cerebral artery bifurcation (4), posterior communicating artery (4), anterior communicating artery (3), superior cerebellar artery (2), ophthalmic artery (2), and one aneurysm of each of cavernous internal carotid artery (ICA), dorsal ICA, and midbasilar artery. In 16 aneurysms (64%), the width of the aneurysm was the same or longer than the height. In 19 (76%), important branches arose from the aneurysm base, and some were even incorporated with the aneurysm fundus. The mean dome (height)-to-neck ratio was 1.23 +/- 0.37 (range, 0.65-2.33), and this was greater than or equal to 1.0 in 19 aneurysms (76%). RESULTS: All aneurysms were successfully embolized. Immediate postembolization angiography showed no residual contrast filling in eight aneurysms (32%), and some residual contrast filling in 16. The aneurysm remnants, however, were intentionally left to preserve important branches in 12 of the 16 aneurysms with incomplete occlusion. Two complications occurred, including one thromboembolic and one coil protrusion, but they were successfully resolved and produced no clinical symptoms. All patients except one showed excellent clinical outcomes. One patient revealed moderate cognitive dysfunction. During the follow-up period, no new bleeding occurred. CONCLUSION: Our experience with 25 cerebral aneurysm patients shows that the technique of using two microcatheters is feasible and safe for coil embolization of aneurysms with unfavorable configurations. Although the lack of angiographic follow-up prevents us from drawing conclusions about its effectiveness as compared with other techniques such as stent placement and balloon-neck protection, we believe that this technique offers a reliable alternative for endovascular therapy of complicated aneurysms.

Adult↗
PubMed2005

Short-term outcome of intracranial aneurysms treated with polyglycolic acid/lactide copolymer-coated coils compared to historical controls treated with bare platinum coils: a single-center experience.

BACKGROUND AND PURPOSE: Aneurysm recanalization is an innate problem in endovascular treatment of aneurysms with coils. A coated coil system, covered with a bioabsorbable polymeric material (polyglycolic acid/lactide copolymer, PGLA), was developed to accelerate intra-aneurysmal clot organization and fibrosis. The purpose of this study was to evaluate the efficacy and safety of the PGLA-coated coils in patients with intracranial aneurysms and to compare the outcome with that of bare platinum coils. PATIENTS AND TECHNIQUES: Fifty-one patients harboring 56 intracranial aneurysms underwent endovascular embolization with the PGLA-coated coils. In the control group were 78 consecutive patients, harboring 87 aneurysms, who underwent coil embolization with bare platinum coils. The authors compared coil volume, packing attenuation, degree of occlusion of aneurysms, procedure-related complications, and follow-up results between the 2 groups. RESULTS: The PGLA-coil group showed comparable data regarding rate of total or near-total occlusion of the aneurysm, incidence procedure-related thromboembolism, and management outcome. Mean coil volume deployed and packing attenuation of the PGLA-coil group were significantly higher than those of the bare-coil group (P = .0026 and P < .0001, respectively). Radiologic follow-up evaluation revealed recanalization in 14 of 39 aneurysms (major recanalization in 5 [13%] and minor recanalization in 9 [23%]) among the PGLA-coil group and in 29 of 64 aneurysms (major recanalization in 9 [14%] and minor recanalization in 20 [31%]) among the bare-coil group. CONCLUSION: In this study, the incidence of recanalization was not different in aneurysms treated with PGLA-coated coils compared with historical controls treated with bare platinum coils.

Adult↗
PubMed2004

Involuntary movement induced by cerebral ischemia: pathogenesis and surgical outcome.

OBJECT: Involuntary movement is an uncommon manifestation of a transient ischemic attack. It may be induced by cerebral hemodynamic insufficiency, which is associated with several cerebral ischemic diseases. The authors present three cases of limb shaking due to moyamoya disease (MMD) or radiation-induced middle cerebral artery stenosis, and three additional cases of choreic movement due to MMD. Neuroimaging studies and surgical outcomes in these patients were retrospectively analyzed to investigate the pathological mechanism underlying the symptoms and to provide guidance for the management of involuntary movement disorders in cases of ischemic cerebral disease. METHODS: The patient population included two children and four adults with ages at presentation ranging between 7 and 50 years. The initial presenting symptoms were involuntary movements in all six cases. A magnetic resonance imaging finding common in all cases was a small infarct in the frontal corona radiata, which did not extend to the cortex or basal ganglia. A perfusion defect in the frontoparietal cortical and subcortical regions was demonstrated by single-photon emission computerized tomography in all patients. Improved hemodynamic circulation in the frontoparietal cortical and subcortical regions occurred in parallel with clinical improvement following indirect or direct bypass surgery. CONCLUSIONS: Ischemic dysfunction of the frontal cortical and subcortical motor pathways rather than that of the basal ganglia was suspected to be the cause of the observed contralateral involuntary movements. Direct and indirect bypass surgery can be used effectively to treat involuntary movements in patients with cerebral ischemic diseases such as MMD and in those with stenosis of an intracranial major artery.

Adolescent↗
PubMed2003

Embolization with autologous fibroblast-attached platinum coils in canine carotid artery aneurysms: histopathological differences from plain coil embolization.

PURPOSE: This study was designed to evaluate the effect of autologous fibroblast-attached platinum coils on the promotion of intra-aneurysmal thrombus organization. MATERIALS AND METHODS: Sidewall aneurysms were surgically created at common carotid arteries bilaterally in 5 dogs. Fibroblasts were obtained from the skins of the dogs and cultured and attached to unmodified platinum coils in a 5-day coculture. In each animal, one aneurysm was embolized with fibroblast-attached platinum coils (study group) and the other with plain platinum coils of the same size (control group). RESULTS: All aneurysms were partially occluded; the mean occlusion rate was 67%. The histologic analyses performed 2 weeks after the embolization showed more advanced organization of intra-aneurysmal thrombus in the study group than in the control group (80% versus 53%, P = 0.02). Overgrowth of the organizing tissue and parent artery stenosis did not occur. CONCLUSION: Our results suggest that autologous fibroblasts delivered with platinum coils could promote the organization of intra-aneurysmal thrombus. Although further research is needed, especially on the potential complications, endovascular treatment using autologous fibroblasts may be applied to aneurysm treatment.

Aneurysm↗
PubMed2003

Primary intraosseous malignant fibrous histiocytoma of the skull: a case report.

Malignant fibrous histiocytoma (MFH) is a rare primary neoplasm that constitutes less than 1% of the malignant tumors of bone, and involvement of the skull is very rare. We present a case of malignant fibrous histiocytoma of the skull, presenting an intraosseous lesion in a 43-yr-old woman. She had a rapidly growing, tender mass in the right parietal region. A plain radiograph showed an osteolytic lesion of the right parietal bone. Magnetic resonance imaging revealed that the lesion showed heterogeneous low signal intensity on T1-weighted images and slightly high signal intensity on T2-weighted images. No evidence of an extraosseous extension to the adjacent dura and soft tissue was found, and a wide excision of the parietal bone was performed. Histologically, the tumor was a typical MFH displaying pleomorphic spindle cells in a storiform pattern. The results of immunohistochemical stainings revealed that the tumor cells were positive for vimentin, alpha-1-antitrypsin, and p53, and negative for smooth muscle actin, S100 protein, desmin, and MyoD1. Three months later, a mainly cystic, recurrent mass was developed at the previously operated site. Before the resection, we first performed the percutaneous aspiration cytology, revealing diagnostic multinucleated pleomorphic cells. Thereafter, she had to receive repetitive resections of recurrent or residual lesions, and she died of postoperative meningoencephalitis two years after the first operation.

Actins↗
PubMed2003

Gas generation and clot formation during electrolytic detachment of Guglielmi detachable coils: in vitro observations and animal experiment.

BACKGROUND AND PURPOSE: Recent reports describe a high rate of thromboembolic events related to Guglielmi detachable coil (GDC) use in the treatment of cerebral aneurysms. The purpose of this study was to investigate electrolysis-related changes of blood as a potential cause of thromboembolic complications associated with GDC use. METHODS: For in vitro observations, 15 GDCs (10 conventional coils and five insulated coils) were experimentally detached under microscopic observation. Three coils were detached in normal saline, five in human serum, and seven in heparinized human blood. For animal experiments, two coils were detached in two canine normal common carotid arteries with systemic heparinization. Immediately after detachment, the arteries were exposed, and clot formations were observed. RESULTS: Significant amounts of gas bubbles were observed in all in vitro observations; more were seen in conventional coils, which required longer detachment times, than in insulated coils. Gas generation started with the growth of tiny bubbles into larger ones. In insulated coils, gas was generated only at the detachment zone, and no difference between saline, serum, and blood environments was observed. During detachment within heparinized blood, clot formations of 2-3-mm diameter were observed at the detachment zones of insulated coils. Animal experiments showed clot formation at the detachment zone, and bubble entrapments around the clots were also found. CONCLUSION: The electrolytic detachment mechanism of the platinum coil can generate gas bubbles during the application of electric current. In association with electrothrombosis, this phenomenon may be a potential cause of thromboembolic complications during the treatment of cerebral aneurysms by use of GDCs.

Animals↗
PubMed2002

A technique for safe withdrawal of a catheter tip that hooks a coil loop.

In cerebral aneurysm embolization with GDCs, coil movement and subsequent coil protrusion or migration may occur during catheter withdrawal. Coil migration or protrusion usually does not produce clinical problems, but sometimes it may do. Because the consequences of coil movement cannot be anticipated exactly, coil motion during a catheter withdrawal makes interventionists nervous. The authors report on a technique for safe withdrawal of a catheter tip that hooks a coil loop using a small soft coil.

Cerebral Angiography↗
PubMed2002

Clinical characteristics of dural arteriovenous fistula.

Intracranial dural arteriovenous fistula (DAVF) is an uncommon neurosurgical condition; in particular, it has been infrequently reported in Korea. To understand the general clinical characteristics of DAVFs, the authors reviewed 53 cases and analyzed factors affecting DAVF hemorrhage of and treatment outcome. Since 1980 we have encountered 480 pial and 53 DAVFs, a ratio of 9.1 to 1. The age of these patients ranged from 1 month to 71 years, the most common being in the 6th decade, and females exceeded males by 1.65 to 1. All lesions except three were single, and symptoms were related to location and the venous drainage pattern. The most common location was the cavernous sinus, accounting for about 64% of cases, with the result that the most common clinical symptoms of DAVFs were ocular, namely proptosis and chemosis. The next was tinnitus also found in transverse-sigmoid sinus DAVFs. Intracranial hemorrhage was seen in eight cases,(15%) the primary cause of hemorrhage was retrograde intracranial venous drainage (P=0.017), and one hemorrhage was observed in cases with no intracranial venous drainage. Intracranial hemorrhage was more frequently in transverse-sigmoid than cavernous sinus DAVFs (P=0.049), and this proved to be so even where there was intracranial venous drainage. However, two of 34 patients with cavernous DAVFs became blind in one eye, demonstrating that in such patients, the clinical course could be aggressive. Thirteen patients were treated conservatively. The conservative treatment group was comprised of 13 patients, two of three patients with transverse-sigmoid sinus DAVF expired, and 7 of 10 with cavernous sinus DAVF experienced a clinical improvement or cure. Surgical excision was performed in only two patients. A total of 39 patients underwent embolization; clinical cure was achieved in 13, improvement of symptoms in 12, an unchanged or aggravated result occurred in 9, one died, and four were lost to follow up. During intervention, there was one hemorrhagic complication, owing to obstruction of the venous outflow with embolic materials. In this study, the most common location of DAVFs was the cavernous sinus. The cortical venous drainage remains the primary determinant of intracranial hemorrhage. Common indications for treatment include hemorrhage and neurological deficit. Endovascular treatment is preferred in the majority of cases except tentorial DAVF. The goal of embolization in cavernous DAVF is the alleviation of symptoms, not angiographic cure. But transverse-sigmoid sinus DAVF with venous restriction and leptomeningeal drainage should be treated aggressively.

Adolescent↗
PubMed2002

Intraosseous dural arteriovenous fistula of the skull base associated with hearing loss. Case report.

The most common clinical presentations of dural arteriovenous fistulas (DAVFs) are bruit, headache, increased intracranial pressure, and intracranial hemorrhage. In particular locations, such as the cavernous sinus or middle cranial fossa, cranial nerve involvement due to dural arterial steal or venous occlusion may develop. A case in which a DAVF is associated with hearing loss, however, has not previously been reported. The authors report a case in which an intraosseous DAVF and associated hearing loss probably resulted from cochlear nerve or vascular compression caused by the draining vein or nidus of the DAVF.

Adolescent↗
PubMed2002

Intraarterially administered abciximab as an adjuvant thrombolytic therapy: report of three cases.

The intravenous administration of abciximab can be used as an adjuvant therapy to facilitate thrombolysis for acute cerebrovascular occlusion. However, to our knowledge, the intraaterial administration of abciximab has not been reported. We recently treated three patients with acute thrombosis of the cerebral arteries by using an intraarterial infusion of urokinase and abciximab. Even with small doses, we achieved rapid and complete recanalization without complications. We believe that the intraarterial infusion of abciximab may be promising for effective and safe recanalization of acute thrombotic occlusion of cerebral arteries.

Abciximab↗
PubMed2002

A technique of GDC embolization for deeply bilobulated aneurysms.

The endovascular occlusion of deeply bilobulated aneurysms is a technical challenge. Recently, we successfully treated three patients with deeply bilobulated aneurysms by using Guglielmi detachable coils. The embolization technique was conventional, but it required several special technical considerations. In this report, we describe the technique of coil embolization of deeply bilobulated aneurysms.

Aged↗