Microsurgical clipping for cerebral aneurysms should be performed under adequate preparations and proper clipping techniques. The patient's head position and surgeon's posture should be determined to minimize brain retraction and ensure the smooth and safe use of surgical tools. The operative field should be wide enough to perform safe and stable clipping, which mainly depends on the surgeon's skills. Proper clips should be applied to proper positions to maintain normal blood flow of parent arteries and preserve perforators. Surgeons must have precise knowledge about materials and mechanical characteristics of clips to avoid incomplete clipping, unnecessary artifacts and side effects.
We investigated the clinical characteristics of intracerebral hemorrhage (ICH) under anticoagulant and/or antiplatelet therapy in 371 cases with spontaneous ICH treated during 2 years between November 2001 and October 2003. Forty-eight out of these 361 cases had received either anticoagulant and/or antiplatelet therapy before and at the onset of ICH. We compared the clinical characteristics of these 48 patients with those who had not received anticoagulant or antiplatelet treatment. Patients were classified into 4 groups: those who had received anticoagulant only (Group A, n=11), both anticoagulant and antiplatelet (Group B, n=11), antiplatelet only (Group C, n=26), and those who had not received anticoagulant or antiplatelet treatment (control group, n=313). There was no significant difference between the control and group A, B, or C in age, sex, history of hypertension, blood pressure at the time of admission, hematoma location, or initial hematoma size. The rebleeding rate was higher in groups with anticoagulant treatment (A, B) than control. Rankin Scale at the time of discharge was significantly worse in groups with anticoagulant treatment (A, B) than control. However, the outcome did not significantly differ between group C (antiplatelet only) and control. Anticoagulant therapy may be a risk factor of rebleeding, clinical deterioration, and poor outcome. In contrast, antiplatelet therapy may not be a risk factor of rebleeding, clinical deterioration or poor outcome.
We evaluated the surgical and long-term follow-up results of VA-CCA transposition in patients with bilateral VA occlusive lesions. Indications for this operation are: 1) symptomatic patients with the infarction in the cerebellum, brain stem or occipital lobe, 2) symptomatic patients with more than 50% VA stenosis with contralateral VA occlusion, 3) symptomatic patients with more than 75% bilateral VA stenosis at origin. In 13 patients, there were no deaths and no major complications. During the follow-up period, 1 patient died of a cardiac event, and another patient had a reattack due to the restenosis of VA stenosis. Another 11 patients showed no reattacks and good patency of VA. Although there have been no prospective randomized studies for this disease, VA-CCA transposition is a safe and useful treatment for patients with bilateral VA origin occlusive lesions.
The surgical treatment of the middle cerebral artery (M1-2 bifurcation) aneurysm (MCA AN) employs the pterional approach and comprises much of aneurysm surgeries. But the surgical management of MCA AN remains a technically challenging problem especially for inexperienced neurosurgeons. This is largely caused by the difficulty of securing the M1 artery as the parent artery before exposing the whole aneurysm. In this study, we retrospectively analyzed the relationship between the approaches and operative difficulties in 90 MCA ANs in 86 of our patients operated on by the same neurosurgeon (K.U.). The variations of the MCA ANs were classified according to the following 3 points: the length of M1, M1 configuration on the angiogram (antero-posterior view), and the aneurysmal dome direction to M2. We subdivided the pterional approach into the following 4 groups: 1) the proximal approach (PA) to secure the proximal M1 after having controlled the internal carotid artery, 2) the distal approach (DA) to secure the distal M1 in the space between M2 arteries after having opened the distal sylvian fissure, 3) the superior approach (SA) to secure the distal M1 after having opened the distal sylvian fissure and followed the medial surface of M2 superior trunk, and 4) the inferior approach (IA) to secure the distal M1 after having opened the distal sylvian fissure and followed the lateral surface of M2 inferior trunk. The PA is effective in the cases of short M1 but in the cases of long M1 the DA is effective. The PA is safe for the cases in which the direction of the aneurysm is at the medial side of M2 arteries. On the other hand, in the cases in which the direction of the aneurysm is lateral to the M2 arteries, DA and SA are safe. In view of the results, we designed a scoring system to indicate the difficulties of securing M1 as the parent artery regarding the above-mentioned 3 points. Using these scores, we were able to decide the optimum approach preoperatively. To secure the parent artery is indispensable to safe aneurysm surgery. Comparing the points of each approach to the aneurysm with this scoring system, we were able to construct a better and safer micro-dissection plan with the goal of securing the parent M1 artery, and perform the operation by following the pre-operative plan. Surgical success or failure is determined by preoperative planning.
The prevention of future stroke is an important issue in hemorrhagic type moyamoya disease. However, the surgical treatment of moyamoya disease in adult hemorrhagic type is still controversial. We undertook the present study to analyze the effect of direct surgery of STA-MCA anastomosis on the prevention of future stroke in patients with the hemorrhagic type of moyamoya disease. We analyzed 30 patients with adult moyamoya disease whose mean age was 44 years old. The follow-up period was from 0.8 to 15.1 years after initial onset of intracerebral hemorrhage. Direct bypass surgery was performed on 10 patients and recurrence of hemorrhage was observed in 1 patient (10%) 9.3 years after first onset of hemorrhage. Indirect surgery was done on 6 patients, and 3 patients had future strokes (50%). Of the remaining 14 patients treated conservatively, stroke recurred in 8 patients (57%) during follow-up (average 2.71 years). The rate of future strokes and stroke-free time in the patients treated with direct bypass surgery was significantly lower (P<0.05) than that of patients managed conservatively or with indirect bypass surgery. In conclusion, in case of adult hemorrhagic type of moyamoya disease, direct bypass of STA-MCA anastomosis effectively prevents rebleeding and ischemic events.
To establish the optimal therapeutic strategy for paraclinoid aneurysms, we retrospectively analyzed our clinical experiences in 51 patients with 54 paraclinoid aneurysms who had been admitted to our institute since April 1994. The aneurysms were classified as Ia (7), Ib (7), II (17), III (21) and IV (2), according to Al-Rodhan et al., and the sizes of aneurysms (mm) were 3-5 in 27, 6-10 in 15, 11-15 in 3, 16-20 in 6 and >21 in 3 cases. Eight cases showed progressive aggravation of visual symptoms, and 3 cases suffered from SAH. Thin-slice CT provided useful anatomical information of the skull base bony structure and subarachnoid space. Open surgery (OS) (clipping 23, coating 2) resulted in complete anatomical cure in 22 cases (88%), and endovascular surgery (ES) (endosaccular occlusion, 23; IC occlusion, 3) resulted in complete anatomical cure in 18 cases (69%). Aneurysms in Groups Ia and II obtained relatively lower anatomical cure in ES when compared with other groups and OS. Treatment-related complications occurred in 2 large cases (aggravation of visual acuity, basal ggl infarction) of OS and in 3 cases (2 premature rupture, 1 borderzone infarction) of ES. OS is recommended for Groups I and II considering anatomical curability. In Group III, OS is recommended for large symptomatic cases and ES for small ruptured cases to prevent symptomatic aggravation. Small asymptomatic cases in Group III should be treated considering treatment-related risks. Observation is recommended in cases of Group IV if they are asymptomatic.
To determine the risk and benefit of emergency helicopter transport of island patients for treatment of subarachnoid hemorrhage (SAH), we retrospectively analyzed 96 consecutive patients with SAH treated in our institution over the last 2 years. The island group consisted of 55 island patients who received emergency helicopter transport, the mean distance and duration of which were 140 km and 40 minutes, respectively. The land group consisted of 41 land patients transported by ambulance. Only one rerupture during flight was confirmed among the island group. Age, sex, and the time interval between onset and admission did not significantly differ between the 2 groups. At admission, there were 3 patients with Hunt & Kosnik (H & K) Grade 5 in the island group, and 7 with H & K Grade 5 in the land group, and the poor-grade patients were fewer in the former (p=0.09). Fifty-two of 55 patients in the island group, and 29 of 41 patients in the land group were treated operatively or interventionally, and 2 of the former and 12 of the latter were conservatively treated mainly because of poor grade, which was significantly different (p=0.003). At discharge, the number of patients with modified Rankin Scale Grade 0, 1, and 2 were 27 in the island group, and 12 in the land group, and the outcome of patients in the former tended to be better (p=0.09). The emergency helicopter medical transport of the patients with SAH was thought to be safe and effective.
We clinically examined the efficacy of motor evoked potential (MEP) by transcranial high-voltage electrical stimulation for intraoperative monitoring in cerebro-vascular disease. In 49 neurosurgical operations for cerebro-vascular disease, transcranial MEP (TCMEP) was recorded by 300-1000 V bipolar stimulation using the screw electrodes with the anode on the affected side. Surface electrodes for electromyographic responses were placed on the bilateral abductor pollicis brevis (APB) and bilateral abductor hallucis (AH) muscles. To remove effects of muscle relaxants on TCMEP, compound muscle action potential (CMAP) by supra-maximum stimulation of the median nerve 2 seconds after transcranial stimulation was recorded in 30 recent operations. In all 40 operations under propofol anesthesia and 6 among 7 cases under volatile anesthesia, MEP was successfully recorded. Postoperative motor paresis occurred in 6 limbs of 4 patients among 54 limbs of 30 patients who had received TCMEP compensated by CMAP by peripheral nerve stimulation and all compensated relative amplitude indexes (CRAIs) of these 6 limbs were less than 0.2. In contrast, in all 48 limbs of 26 patients who had no postoperative motor dysfunction, CRAI had been more than 0.2. These results suggest that our intraoperative TCMEP monitoring by relatively low-voltage (300-400 V) stimulation and compensated by CMAP after peripheral nerve stimulation was safe, easy (no need to expose the motor cortex), relatively accurate and less invasive, and useful especially in cerebro-vascular disease, which often requires a temporary occlusion of the cerebral arteries.
We review our experience treating 25 so-called high-risk patients with asymptomatic high-grade carotid stenosis complicated with coronary artery disease. Twelve patients underwent carotid endarterectomy (CEA) for 13 lesions and 14 patients underwent 15 carotid stentings (CAS). The order and choice (CEA vs. CAS; CABG vs. PCI) of carotid and coronary revascularization were decided case by case, considering mainly the degree of therapeutic emergency. Overall, neurological deficits were seen in 0% after CEA and in 25.6% after CAS each, mainly caused by embolic complications. Deterioration of the modified Rankin scale was seen in only 1 CAS case. Mortality was 0% and no major cardiac complications were seen in any group. The management strategy of combined coronary and asymptomatic carotid stenosis should be decided case by case, considering the degree of systemic atherosclerosis, cardiac conditions, and plaque morphology.
We present 2 cases of arteriovenous malformation (AVM) in children that recurred 5 and 16 years, respectively, after initial total extirpation confirmed by cerebral angiography. In the first case, a parasplenial AVM that presented initially as a hemorrhage in a 5-year-old patient was completely resolved. Sixteen years later, it reappeared posterior to its initial location in the nidus and then ruptured. The second case also presented initially with AVM-related hemorrhage. Five years following extirpation of the diffuse paracallosal AVM in the right frontal lobe, the defect reappeared surrounding the location of the initial lesion and continued to grow. These cases demonstrate that even in cases where cerebral angiography and operative findings confirm total extirpation of an AVM, the AVM may recur after 10 years or longer. Thus, long-term follow-up is recommended in such cases, especially for children.
Various kinds of intraoperative monitoring are used in carotid endarterectomy (CEA) such as somatosensory encephalogram or transcranial Doppler for detection of cerebral ischemia or microembolism. However, anatomical information about arterial wall, which is manipulated directly, is poorly monitored during operation. Postoperative ischemic complication and restenosis can be occasionally caused by failure of manipulation of intimal stump during CEA. Technical defects can be repaired if intramural problems are detected by ultrasonography (USG) during operation. In 24 cases of CEA between October 2001 and March 2004, we performed intraoperative USG to monitor the arterial wall and hemodynamics. Intraoperative digital angiography (DSA) was performed to compare USG findings. We were able to grasp characteristics and extension of plaque before arteriotomy. It was especially useful for the cases whose plaque end was obscure by DSA. An intimal stump on both sides after CEA could be recognized by B-mode scans. Peak systolic velocities measured by the pulse Doppler method were decreased in all cases after CEA. Three cases were repaired following recognition of technical defects by USG. One was an intimal flap over 2 mm; the others were due to residual common carotid artery lesion. In conclusion, intraoperative USG in CEA was useful in terms of grasping both information of vascular wall and intraluminal hemodynamics in real time, and allowed the detection of technical defects that required surgical repair. Intraoperative USG monitoring may improve operative results by reducing technical defects.