Avoiding a Collision in Gamma Knife Radiosurgery : A Modified Mask Fixation Method

Objective@#: The latest version of the Leksell Gamma Knife IconTM allows for mask- and frame-based fixation. Although mask fixation provides fractionated treatment and immobilization using a noninvasive method, it is not free from collision. The authors investigated the collision problem with a modified mask fixation method. @*Methods@#: This study presents a case of two meningiomas in the frontal area, where a collision occurs in the occipital area. A modified mask fixation method was introduced to avoid the collision : first, the edges of the head cushion were cut off and polystyrene beads with a diameter of approximately 5 cm were removed. Next, the head cushion was sealed using a stapler. Finally, the head cushion was flattened in the adapter. We compared the shot coordinates, 3-dimensional (3D) error, clearance distance, and vertical depth of the head cushion between the initial and modified mask fixations. @*Results@#: When comparing the initial and modified mask fixations, the difference in the shot coordinates was +10.5 mm along the y-axis, the difference in the 3D error was approximately 18 mm, and the difference in clearance was -10.2 mm. The head cushion was approximately 8 mm deeper in the modified mask fixation. @*Conclusion@#: Based on these findings, we recommend a modified mask fixation method for gamma knife radiosurgery using ICON with a collision.

Epidemiologic Impact of Rapid Industrialization on Head Injury Based on Traffic Accident Statistics in Korea

OBJECTIVE: The aim of the present study is to estimate the incidence trend of head injury and the mortality based on traffic accident statistics and to investigate the impacts of rapid industrialization and economic growth on epidemiology of head injury in Korea over the period 1970-2012 including both pre-industrialized and post-industrialized stages. METHODS: We collected data of head injury estimated from traffic accident statistics and seven hospital based reports to see incidence trends between 1970 and 2012. We also investigated the population structure and Gross National Income (GNI) per capita of Korea over the same period. The age specific data were investigated from 1992 to 2012. RESULTS: The incidence of head injury gradually rose in the 1970s and the 1980s but stabilized until the 1990s with transient rise and then started to decline slowly in the 2000s. The mortality grew until 1991 but gradually declined ever since. However, the old age groups showed rather slight increase in both rates. The degree of decrease in the mortality has been more rapid than the incidence on head injury. CONCLUSION: In Korea during the low income stage, rapid industrialization cause considerable increase in the mortality and the incidence of head injury. During the high income stage, the incidence of head injury gradually declined and the mortality dropped more rapidly than the incidence due to preventive measures and satisfactory medical care. Nevertheless, the old age groups revealed rather slight increase in both rates owing to the large population structure and the declining birth rate.

A Long-Term Survival Case of a Primary Malignant Intracerebral Nerve Sheath Tumor

We report a long-term survival case of a primary malignant intracerebral nerve sheath tumor (MINST) occurring in the right frontal lobe of a 13-year old boy. After the gross total resection (GTR), we have performed radiation therapy but it recurred 50 months after the surgery, so the second GTR was performed. Later, second tumor recurrence was found 4 months after the second surgery. Subsequently the third GTR, radiotherapy, and chemotherapy were carried out. At present, the patient has been remaining alive for 77 months without evidence of tumor recurrence. According to the previous reports, the primary MINST is very rare : there are only 8 cases reported. It is also a fast-growing, invasive tumor with poor outcome. This is the first case that had no recurrence for 50 months after the surgery among the reported cases that had been followed up for more than 5 years. It is supposed that a period of recurrence free survival after GTR and low mitotic activity are associated with the patient's prognosis. A GTR followed by adjuvant radiation therapy and chemotherapy will be recommended to patients of MINST.

A Clinical Analysis in Risk Factors of Chronic Subdural Hematoma: Focusing on the Age / 대한신경손상학회지

OBJECTIVE: The current understanding reveals that chronic subdural hematoma (CSDH) is mostly the results of direct or indirect head trauma. Other factors such as alcoholism, medication (such as anticoagulants or antiplatelet agents), liver cirrhosis, chronic renal failure and hematologic disease are also well known as causes of CSDH. Of them, the authors attempted to identify the risk factors of CSDH by focusing on the age with a view point of recent increase in the elderly population. METHODS: We retrospectively reviewed 216 consecutive CSDH patients who underwent surgery at our institute between 2002 and 2011. We classified them into two groups according to the patients' age (Group A: or =65 years old). Various factors were investigated for risk factor of CSDH, such as head trauma, chronic alcoholism, epilepsy, previous shunt surgery, underlying disease having bleeding tendency or medication affecting blood coagulation. And these factors were compared between the two groups for statistical significance. RESULTS: Among the 216 patients, group A included 81 patients (37.5%), group B included 135 patients (62.5%). The medication of group B had significantly more proportion than group A, comparing to the result that group B had relatively less proportion of head trauma and alcoholism (p<0.05). And medication was more associated with non-traumatic CSDH, especially in group B. CONCLUSION: As previously reported, head trauma or alcoholism are also most important causes as a risk factor of CSDH of all ages in our study. But medication is more closely related to the incidence of CSDH in group A, than group B.

Comparison with Subcutaneous Abdominal Preservation and Cryoconservation Using Autologous Bone Flap after Decompressive Craniectomy / 대한신경손상학회지

OBJECTIVE: After decompressive craniectomy was performed in patients with severe brain swelling, we were able to preserve autologous bone flap as freeze-preserved state or within abdominal subcutaneous tissue. The aim of this study was to compare the freeze-preservation with the subcutaneous abdominal preservation regarding the effectiveness and safety. METHODS: The clinical data of 53 patients who underwent decompressive craniectomy with autologous bone flap cranioplasty in our department were studied retrospectively. 43 patients underwent cranial reconstruction using autologous bone flap stored in deep freezer. In 10 patients cranioplasty was performed to repair bone defect using autologous bone flap preserved in subcutaneous abdomen. The analysis included the rates of infection, bone absorption and other complications and operation time to compare these two methods. RESULTS: Cranioplasty using deep-freezing bone flap showed a low infection rate (2.3%), low bone absorption (2.3%) and no cosmetic problem. The average time of operation is 146 minutes. Cranioplasty using a bone flap banked in the patient's abdominal wall revealed no case of complications. The average time of operation is 130 minutes. The longer period the bone flap was preserved for, the longer time the operation took in both methods. CONCLUSION: This study may be worth considering that both methods of cryoconservation and subcutaneous abdominal preservetion are feasible for the repair of skull defect although abdominal preservation seems to show better result a little. If the deep-freezer is not available, a bone flap banked in the patient's abdominal wall can be used.

Recent Changes in Risk Factors of Chronic Subdural Hematoma

OBJECTIVE: Chronic subdural hematoma (CSDH) is a typical disease that is encountered frequently in neurosurgical practice. The medications which could cause coagulopathies were known as one of the risk factors of CSDH, such as anticoagulants (ACs) and antiplatelet agents (APs). Recently, the number of patients who are treated with ACs/APs is increasing, especially in the elderly population. With widespread use of these drugs, there is a need to study the changes in risk factors of CSDH patients. METHODS: We retrospectively reviewed 290 CSDH patients who underwent surgery at our institute between 1996 and 2010. We classified them into three groups according to the time of presentation (Group A : the remote period group, 1996-2000, Group B : the past period group, 2001-2005, and Group C : the recent period group, 2006-2010). Also, we performed the comparative analysis of independent risk factors between three groups. RESULTS: Among the 290 patients, Group A included 71 patients (24.5%), Group B included 98 patients (33.8%) and Group C included 121 patients (41.7%). Three patients (4.2%) in Group A had a history of receiving ACs/APs, 8 patients (8.2%) in Group B, and 19 patients (15.7%) in Group C. Other factors such as head trauma, alcoholism, epilepsy, previous neurosurgery and underlying disease having bleeding tendency were also evaluated. In ACs/APs related cause of CSDH in Group C, significantly less proportion of the patients are associated with trauma or alcohol compared to the non-medication group. CONCLUSION: In this study, the authors concluded that ACs/APs have more importance as a risk factor of CSDH in the recent period compared to the past. Therefore, doctors should prescribe these medications carefully balancing the potential risk and benefit.

Unpredictable Postoperative Global Cerebral Infarction in the Patient of Williams Syndrome Accompanying Moyamoya Disease

We report a rare case of Williams syndrome accompanying moyamoya disease in whom postoperative global cerebral infarction occurred unpredictably. Williams syndrome is an uncommon hereditary disorder associated with the connective tissue abnormalities and cardiovascular disease. To our knowledge, our case report is the second case of Williams syndrome accompanying moyamoya disease. A 9-year-old boy was presented with right hemiparesis after second operation for coarctation of aorta. He was diagnosed as having Williams syndrome at the age of 1 year. Brain MRI showed left cerebral cortical infarction, and angiography showed severe stenosis of bilateral internal carotid arteries and moyamoya vessels. To reduce the risk of furthermore cerebral infarction, we performed indirect anastomosis successfully. Postoperatively, the patient recovered well, but at postoperative third day, without any unusual predictive abnormal findings the patient's pupils were suddenly dilated. Brain CT showed the global cerebral infarction. Despite of vigorous treatment, the patient was not recovered and fell in brain death one week later. We suggest that in this kind of labile patient with Williams syndrome accompanying moyamoya disease, postoperative sedation should be done with more thorough strict patient monitoring than usual moyamoya patients. Also, we should decide the revascularization surgery more cautiously than usual moyamoya disease. The possibility of unpredictable postoperative ischemic complication should be kept in mind.

Measurements and Comparative Considerations of Velocities of Primary Bloodstain Spatters using a High Speed Camera / 대한법의학회지

Bloodstain pattern analysis is a forensic discipline that reconstruct events of a crime scene by analyzing sizes, shapes, distributions, positions of bloodstains. Bloodstain pattern can be classified into the low velocity, medium velocity, and high velocity system. Velocities in this system represent the velocity of the wounding agent (the force applied) and not to the velocity of the blood in flight. Thus there is no reference system about the velocity of the blood in flight in the existing bloodstain classification system. Applying bloodstain pattern analysis to the real crime case, we needed to have the reference system of velocities of impact spatter, cast-off spatter, and expectorate spatter. Therefore we measured the velocities of these spatters using high speed camera and we analyzed the results. In this experiments the average velocity of impact spatter that generated by swinging a hammer with all experimenter's strength at the pool of blood is about 4.7 times faster than that of swing cast-off spatter that generated by swinging a red-wat hammer with all experimenter's strength, and about 3.9 times faster than that of expectorate spatter that generated by emitting blood from the mouth with all experimenter's strength. The velocities of cast-off spatter and expectorate spatter, however, showed similar distributions. Our experiments that measure the velocities of droplets of blood spatters in flight under the specific conditions that generated at fastest speed can give some reference to the classification system of velocities of bloodstains which is not distinct up to now, as well as some real bloodshed crime cases.

Ischemic Complication of Ruptured Anterior Choroidal Artery Aneurysm / 대한뇌혈관외과학회지

OBJECTIVE: Vasospasm is known to play the key role in determining the prognosis of aneurysmal subarachnoid hemorrhage (SAH). We have experienced a higher incidence of vasospasm in the cases of SAH caused by rupture of an anterior choroidal artery (AChA) aneurysm than aneurysms of other area. The purpose of this study is to analyze the ischemic complications in patients with a ruptured AChA aneurysm. METHODS: We retrospectively reviewed 13 patients who were treated for ruptured AChA aneurysm from 1994 to 2007 at our hospital. The prognosis and complications were analyzed based on the institution's data, gender, age, the Hunt and Hess grade, the Glasgow coma scale, the Glasgow outcome scale, the symptoms and neurological examinations, the medical treatment, the digital subtraction angiography (DSA), the computed tomography (CT) and the magnetic resonance imaging (MRI). RESULTS: Forty-one (6%) out of 678 SAH patients had ischemic complications. Thirteen cases (2%) were caused by rupture of an anterior choroidal artery (AChA) aneurysm and 3 of these 13 cases (23.1%) had ischemic complications. Two of these 3 cases (15.4%) had neurological abnormality. Twelve out of the 13 AchA aneurysms had the saccular form. CONCLUSION: In cases of SAH from ruptured AchA aneurysm, the probability of ischemic complications was higher than that of general aneurysmal SAH. This seems to be due to the thin AChA and that the vascular territory of AChA is the area where ischemic brain damage can occur even by a mild vasospasm. So, when operating on a AChA aneurysm, maximum effort should be done to preserve the AChA. However, in the exceptional case with multiple AChAs, one AChA can be trapped without a definitive neurological deficit.

Treatment Modalities for Dural Arteriovenous Fistulas (DAVFs) According to Venous Drainage Patterns / 대한뇌혈관외과학회지

OBJECTIVE: The purpose of this study was to analyze the clinical presentation and available therapeutic modalities for treating dural arteriovenous fistulas (DAVFs), according to the angiographic features. (Ed note : "...fistulas (DAVFs), and we wanted to determine their correlation with the angiographic features?") METHODS: We retrospectively reviewed the records of 10 DAVFs patients who were treated at our institution from June 2001 to January 2008. The nature and cause of the clinical presentation was reviewed. The angiographic findings were categorized according the patterns of venous drainage, which were based on the classification system described by Cognard et al.7 The goals (eradication of the AV fistulas vs. interruption of the cortical venous reflux) and the modalities of treatment (endovascular treatment, surgery or radiation therapy) were analyzed according to the angiographic classifications. The angiographic results and clinical outcomes were also assessed. RESULTS: According to Cognard's classification, 2 cases were type I, 3 were type II b, 1 was type II a+b, 2 were type III and 2 were type V, respectively. The initial presenting symptoms included headache (5 cases), pulsatile tinnitus (1 case), visual disturbance (1 case), seizure (1 case), mental change (3 cases) and progressive quadriplegia (1 case). Trans-arterial embolization was adapted as an initial treatment method in 6 cases (1 type I, 1 type II b, 1 type II a+b, 1 type III and 2 type V) with the goal of fistula obliteration or limited interruption of the cortical venous reflux. The procedure was successful in 5 cases (83.3%) and additional craniotomy was necessary in 1 case. Surgery was performed in 4 cases (40%) as the primary treatment modality because of the lack of endovascular accessibility or the complexity of the anatomical relationships. The surgical results were successful in all cases and no further endovascular treatment was required. Among the 9 patients who experienced the angiographically determined disappearance of DAVFs, 6 patients were rated as 5 for the Glasgow outcome scale (GOS) score, 2 patients were rated as 4 and 1 patient was rated as 3. One patient with angiographically determined incomplete obliteration showed a GOS of 3. CONCLUSIONS: The venous drainage pattern is a single most important factor for determining the clinical presentation, the treatment planning and the outcome. An endovascular procedure can be chosen as an initial treatment modality when feasible. Surgery is required for more complex and aggressive lesions with cortical venous reflux.

Dissecting Aneurysm of the Anterior Cerebral Artery with Spontaneous Subarachnoid Hemorrhage

A 58-year-old woman was admitted to our department due to headache. Brain computed tomography (CT) indicated subarachnoid hemorrhage (SAH), and emergency angiography showed dissecting aneurysm involving the left A1 segment. We performed trapping of dissecting A1 aneurysm and the postoperative course was uneventful. We present a case of dissecting aneurysm in the anterior cerebral artery with spontaneous SAH which was treated by early surgery and resulted in clinically good prognosis.

Central Nervous System Infection Related to Intracranial Indwelling Catheters / 대한뇌혈관외과학회지

OBJECTIVE: Infection of the intracranial catheter remains the main morbidity and mortality associated with this procedure. In this retrospective study we have collected the information regarding the occurrence of this disease in order to find ways to reduce the incidence of central nervous system (CNS) infection related to an intracranial indwelling catheter. METHOD: In a six-year retrospective study we selected and reviewed the records of 242 patients (with a total of 314 catheters). We analyzed the incidence of infection, etiologic bacteria and factors affecting the risk of infection: catheter duration, catheter sequence, concurrent craniotomy, subcutaneous tunneling of catheter, cerebrospinal fluid (CSF) draining catheter, urokinase irrigation. RESULTS: Nineteen patients were infected. the infection rate was thus 8%. Staphylococcus aureus and Coagulase-Negative Staphylococcus are the most frequently-involved pathogens. The onset of infection ranged from 6 days to 38 days (with a mean of 14 days). There was a significant association between infection and a CSF draining catheter, a concurrent craniotomy, no subcutaneous tunneling, the duration of the catheter and multiple sequential catheters in the univariate logistic regression model. There was, however, no significant association between a CSF draining catheter and infection in the multivariate logistic regression model. CONCLUSION: The result of this study suggests that long catheter duration, no subcutaneous tunneling, multiple sequential catheters, concurrent craniotomy increase the incidence of CNS infection related to an intracranial indwelling catheter. An intracranial catheter must be placed using aseptic procedures with subcutaneous tunneling and maintenance of a strict closed system alsoshort duration as possible as.

Use of Prophylactic Decompressive Craniectomy in Middle Cerebral Artery Aneurysmal Subarachnoid Hemorrhage Patients Presenting with Associated Large Hematoma / 대한뇌혈관외과학회지

OBJECTIVE: Patients who present with a poor Hunt-Hess grade (IV or V) after aneurysmal subarachnoid hemorrhage (SAH) often have a poor prognosis. However, there may be subgroups of these patients for whom the sustained increased intracranial pressure predominates due to a large sylvian hematoma and for which rapid decompression of these predominant pathological processes may result in an improved outcome. We report here on the use of prophylactic decompressive craniectomy in patients who present in a poor neurological condition or they have a focal neurologic deficit, such as motor aphasia, after SAH from middle cerebral artery aneurysms with associated large sylvian fissure hematomas. METHODS: Twelve patients (mean age: 52yr, age range: 13-71yr) presented with middle cerebral artery (MCA) aneurysmal SAH (one with Hunt-Hess grade III, five with Hunt-Hess grade IV and six Hunt-Hess grade V). They all had large hematomas (mean hematoma volume: 70ml, range: 30-120ml). All the patients underwent emergency operation. One patient whose Hunt-Hess grade was III underwent decompressive craniectomy because she had motor aphasia due to a focal mass effect of the hematoma. Five of them underwent operation without conventional angiography. All the patients were treated with large craniectomy and duraplasty. RESULTS: All patients underwent craniectomy without operative complications. The results for this study demonstrated that craniectomy patients had a remarkably high rate of good recovery or they had moderately disabled outcomes. The outcomes of the craniectomy patients were three grade 5s, four grade 4s, one grade 3 and four grade 1s for the GOS. CONCLUSION: The data in this study showed that decompressive craniectomy can be performed safely as part of the initial management for patients with SAH and who also present with large hematomas. We suggest decompressive craniectomy when patients with a large hematoma present not only with deteriorated mentality due to the increased intracranial pressure, but also with focal neurologic deficits such as motor aphasia due to the local mass effect.

Efficacy and Rebleeding Risk of Preoperative Ventriculostomy in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: Despite the widespread use of preoperative ventriculostomy in aneurysmal subarachnoid hemorrhage (SAH), there is no general consensus regarding the risk of bleeding associated with its use before aneurysm repair. This study was conducted to define the efficacy and rebleeding risk of ventriculostomy in aneurysmal SAH. METHODS: The authors reviewed 339 consecutive patients with aneurysmal SAH who were treated at our hospital between January 1998 and December 2004. RESULTS: Preoperative ventriculostomy was performed on 73 patients for acute hydrocephalus after aneurysmal SAH. The Hunt-Hess (H-H) grades of patients who underwent ventriculostomy were higher. Out of the 73 patients who underwent preoperative ventriculostomy, 58 (79%) demonstrated immediate clinical improvement after ventriculostomy. Of those same 73 patients, 22 (30%) suffered aneurysmal rebleeding, whereas only 11 (4%) of the 266 patients who did not undergo ventriculostomy showed preoperative aneurysm rebleeding. The causes of rebleeding in the 22 patients who underwent ventriculostomy before surgery were related to the ventriculostomy procedure itself, subsequent cerebrospinal fluid (CSF) drainage, angiography and patient care procedures, such as endotracheal suction and nursing care. The mean time interval between SAH and surgery in the patients who underwent ventriculostomy was not statistically different from those who did not receive preoperative ventriculostomies (44.66 compared with 42.13 hours; p=0.73). CONCLUSION: The preoperative ventriculostomy improved patients' clinical condition but increased the risk of rebleeding after aneurysmal SAH. When necessary, however, rapid change in transmural pressure during ventriculostomy must be avoided, careful management during ventricular drainage is needed, and surgery should be performed as soon as possible to prevent or reduce the incidence of rebleeding.

Lymphangiohemangioma of the Mediastinum: A case report / 대한흉부외과학회지

A case report of lymphangiohemangioma of the mediastinum that was misdiagnosed as thymic origin mass on chest CT and MR angiography. Operative finding revealed vascular proliferation originated from innominate vein and the pathologic finding showed both lymphatic and vascular component which was diagnosed lymphangiohemangioma.

Cavernous Hemangioma in the Middle Cranial Fossa & Cavernous Sinus

Extracerebral cavernous hemangiomas are rare vascular tumors that are very difficult to remove because of severe intraoperative bleeding. We report a case of 57-year-old male with extracerebral cavernous hemangioma with review of 126 cases in the literature. Patient presented with blurred vision, diplopia, numbness on the left side of his face. Magnetic resonance imaging revealed a well defined mass of 3 x 4 x 3 cm size with heterogenous iso-or hypointensity on T1-weighted image showing strong homogenous contrast enhancement and marked hyperintensity on T2-weighted image. Digital subtraction angiography(DSA) revealed a faint tumor blush by feeders from the left internal carotid artery(ICA) and left external carotid artery(ECA) in the delayed phase. Even with profuse intratumoral bleeding, near total removal was achieved. In addition to preoperative neurologic deficits such as ophthalmoplegia, facial numbness in the V1-2 dermatomes, ptosis appeared postoperatively.

Delayed Hemorrhagic Manifestation of Blunt Carotid Artery Injury

Blunt carotid artery injury is uncommon, yet not rare. However, it is often underdiagnosed because of inconsistent early symptoms or masking by the presence of coexisting brain and spinal injuries. The delay between the accident and the onset of cerebral ischemic symptoms is variable and has been reported to range from minutes to ten years. However, to our knowledge, there has been no report on a case presented with delayed intracerebral hemorrhage 25months after blunt carotid artery injury. We report on a case with discussion of supporting evidence and possible mechanisms.

Comparative Study on Frameless Stereotactic Hematoma Aspiration versus Frame-Based Stereotactic Hematoma Aspiration in Deep Seated Intracerebral Hemorrhage: A Clinical Article / 대한뇌혈관외과학회지

OBJECTIVE: We compare the frameless stereotactic hematoma aspiration (FSA) with frame-based stereotactic hematoma aspiration (FBSA) in intracerebral hemorrhage (ICH) about operative advantage and result. MATERIAL AND METHODS: Between January 2002 and December 2002, we surgically treated 30 patients presenting with spontaneous ICH at our hospital. 15 patients underwent FBSA via Codman-Roberts-Wells system and catheter placement with urokinase infusion and drainage, and 15 patients underwent FSA and catheter placement via neuronavigator with urokinase infusion and drainage. RESULTS: The amount of remaining hematoma and removal rate were from 1 to 26 and 76% in FSA and from 2 to 55 and 60.4% in FBSA. The entry point was selected within 2.03+/-0.85 cm in a frontal direction from Kocher's point and 2.86+/-0.57 cm in lateral direction from Kocher's point and the trajectory was selected toward the distal margin of hematoma along the long axis of hematoma in FSA but the entry point was restricted within Kocher's point and the trajectory was selected toward the center of the maximum axial section of hematoma in FBSA. The mean time of operative preparation was mean 61 minutes in FSA and 78 minutes in FBSA. The number of patients not required with infusion of urokinase was 10 in FSA and 7 in FBSA. The mean duration of urokinase infusion was 3.6 day in FSA and 4.1 day in FBSA. CONCLUSION: FSA is fast, simple and effective procedure. In comparison with FBSA, FSA has advantage in selecting the entry point and the trajectory for hematoma aspiration and catheter placement, and in a less time-consuming procedure.

Perivascular Delivery of Paclitaxel with F-127 Pluronic Gel Inhibits Neointimal Hyperplasia in a Rat Carotid Artery Injury Model

BACKGROUND AND OBJECTIVES: The local delivery of drugs to the arterial wall represents a strategy for the treatment of fibroproliferative vascular disease. Paclitaxel has been shown to inhibit vascular smooth muscle cell proliferation and migration, which contribute to neointimal formation. This study tested whether the perivascular delivery of paclitaxel can prevent neointimal formation in a rat carotid artery injury model. MATERIALS AND METHODS: The ability of locally-administered paclitaxel to prevent the neointimal hyperplastic response was tested by incorporating 10 microgram paclitaxel into 40% F-127 pluronic gel, which was then applied to the adventitial surface of the rat carotid artery immediately following balloon injury. Fourteen days after angioplasty, the neointimal growth was compared between paclitaxel- (n=12) and pluronic gel only treated (control group, n=11) rats. RESULTS: The paclitaxel-treated group showed significant neointimal formation reductions compared to the control group (0.10+/-0.05 versus 0.21+/-0.05 mm2, p<0.05). The perivascular application of paclitaxel produced a highly localized pattern of neointimal growth inhibition in the arterial cross-section. Although 10 microgram paclitaxel showed no significant cytotoxicity, 20 microgram paclitaxel (n=3) demonstrated cytotoxicity, with medial cell drop out in the region of application. CONCLUSION: We have demonstrated that the local extravascular application of 40% F-127 pluronic gel containing paclitaxel provides an effective mechanism for inhibiting the proliferative response to vascular injury in the rat. The cellular response to paclitaxel is highly focal. Locally sustained delivery of paclitaxel, as little as 10 microgram, was effective in preventing neointimal growth, without destroying medial wall smooth muscle cells.

Frequency of Aneurysmal Subarachnoid Hemorrhage in Perimesencephalic Subarachnoid Hemorrhage and Need of 4-vessel Angiography

OBJECTIVE: In this study, each of the frequency of nonaneurysmal perimesencephalic subarachnoid hemorrhage(N-PMSH), and the clinical and radiologic features, incidence and location of aneurysmal perimesencephalic subarachnoid hemorrhage(A-PMSH), based on aneurysmal rupture and nonaneurysmal subarachnoid hemorrhage in patients with spontaneous subarachnoid hemorrhage, are investigated for clinical application. METHODS: Patients who showed perimesencephalic subarachnoid hemorrhage, among the 388 patients with subarachnoid hemorrhage admitted into the our hospital from March 1994 to November 2002, were extracted ; and their charts and angiographies were examined retrospectively. They were divided into two groups - aneurysmal perimesencephalic subarachnoid hemorrhage group and nonaneurysmal perimesencephalic subarachnoid hemorrhage group - and comparative analysis was conducted on the clinical patterns and radiologic characteristics of each group. RESULTS: There were 22 patients(5.68%) with perimesencephalic subarachnoid hemorrhage(PMSH) among 388 patients with spontaneous subarachnoid hemorrhage. Of the 22 PMSH, 8 patients(36%) were aneurysmal PMSH(A-PMSH), 14 patients(64%) were nonaneurysmal PMSH(N-PMSH). N-PMSH occurred not only in the posterior circulation(5 cases), but also in the anterior circulation(3 cases). There was no difference in the CT features of PMSH between aneurysmal and nonaneurysmal cause. CONCLUSION: According to the above results, 4-vessel angiography is essential for patients with perimesencephalic subarachnoid hemorrhage, and CTA and MRA can be used as assisting diagnosis methods.