Endoscopic surgery has become recognized as a less invasive and safe surgery for putaminal hemorrhage. However, the operative technique has remained controversial. The approach for endoscopic surgery for putaminal hemorrhage in our institution was examined. We started performing endoscopic surgery for putaminal hemorrhage in January 2006, and examined 92 patients treated with this approach. A rigid endoscope and irrigation suction were used, with a “Freehand Technique”, as previously described. The mean age of patients was 61.1 ± 11.3 years, and the mean hematoma volume was 65.4 ± 27.6 mL. Local anesthesia was used for endoscopic surgery in 66.3% (61/92) of patients. The mean operation time was 89.8 ± 30.2 min, and the mean hematoma removal rate was 94.2 ± 9.7%. The re-bleeding rate was 4.3%, and the rate of mortality caused by rebleeding was 2.2% (2/92). Based on this experience, a few points related to endoscopic hematoma evacuation of putaminal hemorrhage were identified. The first point is the use of a clear sheet, allowing visualization of operative markers such as the nasion and external auditory canal. The second point is the method of connection for the irrigation suction, which allows the operator to independently perform coagulation of bleeding points. Using a “Freehand Technique”, it is not necessary to use other precision instruments, and it is easy and safe to insert a sheath into the hematoma. We consider that this technique may be a less invasive, simple, and effective method for treating putaminal hemorrhage.
We have accumulated surgical experience with keyhole clipping for small anterior circulation aneurysms. Recently, we used not only motor evoked potentials (MEP) and indocyanine green video-angiography (ICG) but also a rigid scope during surgery to compensate for the narrow working angle, which is a major disadvantage of keyhole surgery. Between April 2013 and August 2014, we performed endoscope-assisted keyhole clipping for 27 aneurysms in 24 consecutive patients. A supraorbital keyhole for internal cerebral artery aneurysms (IC An.), lateral supraorbital keyhole for anterior communicating artery aneurysms (A-com An.), and pterional keyhole for middle cerebral artery aneurysms (MC An.) were conducted. The optimal keyhole and patient's head position were planned for each individual with a preoperative simulation system using three-dimensional computed tomography angiography. A rigid scope (EndoArm, OLYMPUS) was used to observe the aneurysms before and after clipping. Of 27 aneurysms in 24 operations, supraorbital keyhole, lateral supraorbital keyhole, and pterional keyhole were used for seven, nine (including one case of A-com An. and IC-posterior communicating artery An.), and eight (including two cases of multiple MC An.) operations, respectively. The endoscope provided a favorable enhancement of the visual field. No adverse effects were observed. All of the aneurysms but one IC An. (96.3%) were inspected using endoscopy both before and after clipping. The post-clipping inspection revealed two cases (7.7%) with incomplete clipping of the A-com An. We used an additional clip in one case and rearranged the clip in the other one. In one case (3.8%) of MC An., clip rearrangement after endoscopic evaluation was necessary because of branch occlusion. Although the 0 and 30-degree rigid scopes were very useful, the 70-degree scope was too difficult to guide to the aneurysms for observation. Endoscopic inspection before and after clipping during keyhole surgery might be an effective and safe method to increase treatment quality. Although a larger study is needed to support these findings, the likelihood of unexpected results could be decreased with the combined use of an endoscope, Doppler, ICG, and MEP.
Objective: Distal anterior cerebral artery (distal ACA) aneurysms are relatively rare, and have unique clinical and surgical features compared with intracranial aneurysms at other sites. In this study, we reviewed 24 patients with distal ACA aneurysms with regard to preoperative planning and surgical strategies. Material and methods: Of 24 patients, 15 were women and nine were men. Nineteen had ruptured aneurysms, whereas the remaining five had unruptured aneurysms. The aneurysms were located in four different parts of the distal ACA: two in the superior part of A3, 15 in the anterior part of A3, six in the inferior part of A3, and one in the trunk of A2. Results: All patients underwent surgery via the unilateral frontal interhemispheric route. The location of craniotomy was adjusted anteriorly, depending on the positional relationship of the aneurysm and the genu of the corpus callosum identified through sagittal three-dimensional computed tomography maximum intensity projection (3D-CT MIP) imaging. In all cases, we first entered the interhemispheric fissure towards the back of the aneurysm. The distal segment of the pericallosal artery was identified and dissected in a retrograde manner toward the aneurysm. We were able to predict the location of the aneurysm by recognizing the branching points of the cortical arteries, such as the middle and posterior internal frontal artery. We were able to approach the distal neck of the aneurysm as expected. As the dome of the aneurysm usually extended to the right or left side, exploration of the proximal segment of the pericallosal artery could be achieved by passing the opposite side of the dome. In 22 of the 24 patients, proximal control of the parent artery was achieved before preparation of the neck. In the remaining two patients, proximal control was achieved using tentative clipping. At the time of clip placement, parallel clipping of the pericallosal artery was required in nine patients, double clipping in four, and shank clipping in two. No patient experienced premature rupture during the procedure. Discussion and conclusion: 3D-CT imaging was very useful in planning the surgical strategy; it not only indicated the location of the aneurysm but also the location of the frontal bridging vein and the genu of the corpus callosum. We were able to determine the optimal location of the craniotomy on the basis of sagittal 3D-CT MIP imaging. The procedure, which involves approaching the aneurysm in a retrograde manner from the distal segment of the pericallosal artery, is considered safe because of good orientation and a low incidence of premature rupture. The parent artery is generally small compared with the aneurysmal neck; therefore, maximum precautions against kinking of the parent artery should be taken during clip placement. We concluded that the surgical management of distal ACA aneurysms is challenging, but safe with sufficient preoperative evaluation and experience.
Distal anterior cerebral artery aneurysms (DACA-ANs) are relatively uncommon and lead to some unique operative difficulties. We retrospectively reviewed 18 cases of DACA-ANs, treated in our institute between April 2007 and October 2013, with regard to anatomical features and surgical approaches. DACA-ANs were categorized into three groups: infra-, anterior-, and supra-genu types, based on their anatomical relationship with the genu of the corpus callosum. The most common location was the bifurcation of the pericallosal and callosomarginal arteries (50%). DACA-ANs were infra- in 5, anterior- in 11, and supra- genu in 2 cases. The interhemispheric approach (IHA) was selected in all cases except in one. DACA-ANs were clipped via the basal, anterior, and superior IHA in 5, 11, and 1 cases, respectively. Selection of microsurgical trajectory to the aneurysm based on the anatomical architecture of the ACA and genu of the corpus callosum is vital to occlude aneurysms safely with proximal control established.
The surgical clipping of anterior choroidal artery (AChA) aneurysms has an increased risk of ischemic complications owing to the critical territory that is supplied by the AChA. We retrospectively analyzed 27 patients (28 AChA aneurysms; 10 men, 17 women; mean age: 57.6 years), including 16 patients with subarachnoid hemorrhages, who were treated with surgical clipping between April 1990 and October 2013. At our institution, we have been performing intraoperative monitoring of motor evoked potentials (MEPs) and indocyanine green videoangiography (ICG-VAG) since 2008. On the basis of preoperative cerebral angiography and intraoperative findings, we created the following new classification system of AChA aneurysms, according to the AChA branching point: A, artery type (4, 14.3%); B, neck type (19, 67.8%); C, dome type (1, 3.6%); and D, duplication type (4, 14.3%). Clinical outcomes were evaluated by the modified Rankin Scale at the last follow-up examination. There were three patients with AChA syndrome after clippings that were performed without MEP/ICG-VAG. However, after the introduction of MEP/ICG-VAG, the outcomes of surgical clippings significantly improved (p = 0.005). Three patients had incomplete clippings because the AChA branched from the aneurysmal neck and dome (types B, C, and D). Furthermore, in three cases, we could not detect the duplicated AChA (type D) with preoperative angiography. In some cases with AChA aneurysms, in which complete clipping is difficult because of the AChA branching type, MEP/ICG-VAG monitoring and a precise understanding of the AChA classification (branching pattern) are necessary for good outcomes.
Object: Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease improves tissue oxygen metabolism by increasing perfusion pressure. On the basis of the hypothesis that an improvement in oxygen metabolism may increase venous oxygen saturation (SO2), we assessed changes in venous redness, which reflect venous SO2, during the revascularization surgery. Methods: In this study, venous redness in subjects was quantitatively measured as an R value of RGB (red, green and blue) on the digital images of operative fields. First, to ensure whether redness of blood reflects SO2, we studied the relationship between R values and the SO2 levels of seven blood samples with various degrees of SO2. Subsequently, by reviewing the video recordings of consecutive 14 STA-MCA anastomosis for moyamoya disease, changes in the R value (ΔR) of the cortical veins were compared with those in the regional cerebral blood flow (ΔrCBF) after the surgery. Results: A positive correlation was noted between R values and SO2 of the 7 blood samples (r2 =0.847, P=0.003). The ΔR of the cortical veins during surgery positively correlated with ΔrCBF (r2 =0.473, p=0.007). Notably, prominent venous reddening was associated with an excess increase in postoperative CBF (>150%). Conclusions: During STA-MCA anastomosis, reddenings of cortical veins is proportional to increases in postoperative CBF. Prominent venous reddening, which may reflect excess oxygen supply, suggests postoperative hyperperfusion.
Until 2001, subarachnoid hemorrhage (SAH) patients aged 80 years or older were, as a rule, treated with delayed surgery or conservative methods at our department. Since 2002, with the introduction of endovascular treatments, we have offered acute surgery as a treatment option for SAH patients aged ≥80 years. In the present study, we examined the effect of acute surgery on clinical outcomes in these elderly patients. The subjects were 34 patients aged ≥80 years who had been admitted to our hospital with a diagnosis of SAH (Hunt and Kosnik grade 1 to 4). The subjects were divided into two groups according to the admission time: the early group included patients admitted through 2001, and the late group included those admitted in 2002 or later. Patients in the early group received conservative treatment, while those in the late group were offered acute surgery as a treatment option. Neurological conditions, cerebral aneurysm localization, and clinical outcomes at the time of discharge were compared between the two groups. The early group consisted of 13 patients ranging in age from 81 to 88 years. On admission, 6 patients had severe neurological conditions (Hunt and Kosnik grade 4). Cerebral aneurysms were located at the internal carotid artery (n = 2), anterior communicating artery (n = 1), and vertebral or basilar artery (n = 2). The remaining patients were not tested (n = 8). The modified Rankin scale scores at discharge were 0 to 3 (2 patients) and 6 (11 patients). The late group included 21 patients ranging in age from 80 to 92 years. On admission, 9 patients had severe neurological conditions (Hunt and Kosnik grade 4). Cerebral aneurysms were located at the internal carotid artery (n = 12), middle cerebral artery (n = 5), anterior communicating artery (n = 2), and vertebral or basilar artery (n = 2). Fifteen of the 21 patients underwent acute surgery (clipping in 8 patients and coil embolization in 7 patients). The modified Rankin scale scores at discharge were 0 to 4 (9 patients), 5 (6 patients), and 6 (6 patients). There were no significant differences in age or neurological condition between the two groups. Mortality at the time of discharge was significantly lower in the late group than in the early group. Although it was not statistically significant, the percentage of patients who were discharged to their home (modified Rankin scale scores of 0 to 4) in the late group was approximately three times higher than that in the early group. Of the patients who underwent surgery, 6 had poor clinical outcomes at the time of discharge (modified Rankin scale scores of 5 or 6), attributable mainly to symptomatic cerebral vasospasm and complications of surgery. The incidence of symptomatic cerebral vasospasm was noted to be significantly higher in these subjects than in SAH patients younger than 80 years. We consider prevention of symptomatic cerebral vasospasm and complications of surgery to be essential for improving the clinical outcomes of elderly SAH patients undergoing acute surgery.
Cerebral venous thrombosis is a rare and uncommon type of stroke, and the deep venous system is affected in approximately 10% of cases of cerebral venous thrombosis. The clinical presentation of deep cerebral venous thrombosis is variable and nonspecific, and hence, it is difficult to diagnose this condition. In this report, we describe three cases of deep cerebral venous thrombosis. All the cases presented with mild decreased consciousness, and two cases also experienced quadriparesis. Magnetic resonance (MR) images demonstrated vasogenic edema in the thalamus/thalami, and T2* -weighted MR images indicated a thrombus in the deep venous system in all the cases. Hence, T2* -weighted MR images and magnetic resonance venography is useful for the early diagnosis of deep cerebral venous thrombosis, which can be followed by prompt treatment.
We report a case of convexity subarachnoid hemorrhage (cSAH) associated with vertebral artery (VA) stenosis. A 65-year-old man was admitted to our hospital with a complaint of headache and recurrent transient diplopia. An MRI-fluid attenuated inversion recovery revealed subarachnoid hematoma localized in the cerebral sulci of both occipital lobes. An MRI-gradient echo T2 weighted image revealed an older hematoma in the sulci of both parietal lobes. Vertebral angiography revealed severe stenosis of the right VA at the V4 segment. The left VA was not visualized after the origin of the posterior inferior cerebellar artery, and the territory of the posterior cerebral artery was mainly perfused by the leptomeningeal anastomosis derived from the middle cerebral artery. 123I-IMP SPECT showed reduced cerebrovascular reserve capacity in both occipital regions. We performed balloon angioplasty to treat the right VA stenosis. The VA was dilated successfully and there were no remarkable complications associated with the procedure. After angioplasty, the patient's headache and diplopia resolved completely. cSAH can occur due to several causes. In this case, the insufficient cerebral blood flow and the dilation of the pial arteries due to VA stenosis were thought to cause rupture of the fragile subarachnoid vessels. Angioplasty was found to be an effective treatment.
In an epidemiological study in Japan, tentorial dural arteriovenous fistulas (DAVFs) were less common than cavernous sinus and transverse-sigmoid sinus DAVFs (3.2% versus 45.5% and 28.3%, respectively); however, tentorial DAVFs have the most aggressive neurological behavior, with 97% causing hemorrhage or progressive focal neurological deficits. Tentorial DAVFs were classified into six types by Lawton et al. in 2008. In their literature, Type I Lawton classification was defined as a Galenic DAVF, all of which were Borden Type 3. Neuroendovascular therapy has become the predominant treatment modality for intracranial DAVFs because the arterial supply from the external carotid artery (ECA) can be embolized safely, and the localization near the dural venous sinuses facilitates access and occlusion through that sinus. The combination of transarterial and transvenous embolization results in high obliteration rates for most DAVFs, but tentorial DAVFs are an exception. Their arterial supply is extensive, involving meningeal arteries from the internal carotid artery and vertebral artery, both of which are difficult to cannulate, and embolization is more risky compared to that of the ECA feeders. Transvenous navigation in deeper locations around the tentorium is difficult. More importantly, tentorial DAVFs (especially, Galenic DAVFs) often drain exclusively into the subarachnoid veins rather than into their associated sinuses (Borden Type 3), which prevents transvenous access. Therefore, the management of tentorial DAVFs may require microsurgical interruption, unlike most other DAVFs. We report a case of an isolated Galenic DAVF associated with Marfan syndrome that could be completely cured with transvenous embolization alone.
Coil embolization for cerebral aneurysms of the vertebral basilar artery system includes trans-femoral, trans-brachial, and trans-radial approaches. However, these approaches are affected by stenosis or flexion of the proximal vertebral artery in many cases. In this study, we report the case of a patient in whom unilateral hypoplasia of the vertebral artery and marked cervical flexion on the contralateral side was used to treat a ruptured basilar aneurysm using the trans-femoral approach alone, combined with direct percutaneous puncture of the cervical vertebral artery. A 73-year-old woman was hospitalized because of subarachnoid hemorrhage, and a broad-neck aneurysm was detected at the bifurcation between the posterior cerebral artery on the left side of the basilar artery and the superior cerebellar artery. The aneurysm was present at a high position, and the basilar artery was convoluted at the origin of the aneurysm, because of which clipping was difficult. We planned coil embolization with balloon remodeling technique or double catheters, but the left vertebral artery, primarily supplying the basilar artery, was markedly convoluted at 2 points in the cervical region, because of which inserting a parent catheter was difficult. As the right vertebral artery was extremely thin before the vertebrobasilar junction, there was no blood flow after the balloon was inserted for remodeling, and it was impossible to insert a microcatheter. The balloon was left in place, and the left cervical vertebral artery was percutaneously punctured distal to the site of convolution to insert a microcatheter. Embolization was performed using the balloon remodeling technique without any serious complication. According to previous studies, the methods for direct percutaneous puncture of the cervical vertebral artery include: 1) changing the position after initially reaching the vertebral body, 2) using a roadmap, and 3) using an ultrasound-guided method. In terms of complications, hemorrhage at the puncture site, arterial dissociation, arteriovenous fistula formation, and aneurysm formation have been reported. Although this procedure is useful, it is technically difficult, and complications may develop. Therefore, it should be indicated for patients in whom all other methods are impossible.