Non-traumatic dissecting aneurysms on the intracranial internal carotid artery: report of three cases

Subarachnoid hemorrhage (SAH) due to non-traumatic dissecting aneurysms is uncommon. Most of such cases are reported to occur in the posterior circulation. We encountered three cases of non-traumatic dissecting aneurysms on the intracranial internal carotid artery. Two cases developing SAH from the dissecting aneurysms were surgically treated by such means as proximal ligation and trapping. Two cases, which were treated surgically during the acute phase, showed poor surgical outcome, because a large cerebral infarction took place during the course of vasospasm. Trapping of the ICA or the contralateral ICA with the dissecting aneurysm failed to keep enough blood supply despite hypervolemic hypertensive therapy. Operative results seemed to depend on the collateral circulation during vasospasm, so appropriate bypass surgery was recommended in cases of dissecting aneurysm on the ICA manifesting SAH. Furthermore, the mechanism of initiation of a dissecting aneurysm on the intracranial carotid artery was discussed from the biorheological aspect.     

Subarachnoid hemorrhage in the presence of both intracranial dissecting and saccular aneurysms--two case reports

Two patients presented with subarachnoid hemorrhage (SAH) associated with both intracranial dissecting and saccular aneurysms. Case 1, a 48-year-old woman, had a saccular aneurysm of the right internal carotid artery and dissecting aneurysms of the bilateral vertebral arteries. Case 2, a 52-year-old man, had three saccular aneurysms in the anterior circulation and a dissecting aneurysm of the unilateral vertebral artery. A saccular aneurysm was responsible for the SAH in both patients. Ruptured saccular aneurysms were treated with surgical clipping and unruptured dissecting aneurysms remained untreated. SAH recurred due to bleeding from an untreated dissecting aneurysm 4 days after the initial SAH in Case 1. Triple-H therapy, which causes increased hemodynamic stress, was not administered for symptomatic cerebral vasospasm after SAH in Case 2, because of the risk of bleeding from the untreated dissecting aneurysm, and the patient suffered cerebral infarction. The risk factors for this rare association are unclear, but both patients were smokers and had hypocholesterolemia including low apolipoprotein E levels. The clinical management of patients with SAH and both dissection and saccular aneurysms is complicated. Asymptomatic dissecting aneurysm has a benign clinical course in general, but hemodynamic stress related to stroke may induce abrupt development of dissecting aneurysms. Prophylactic obliteration during the acute stage of SAH may provide better outcomes if the unruptured dissecting lesion appears as obvious aneurysmal dilatation or pearl-and-string sign and is safely treatable with endovascular trapping.     

Non-saccular aneurysms of the supraclinoid internal carotid artery trunk causing subarachnoid hemorrhage: acute surgical treatments and review of literatures

Non-saccular aneurysms (NSAs) of the internal carotid artery trunk include blood blister-like aneurysms (BBAs) and dissecting aneurysms (DAs), which are susceptible to disastrous intra- and postoperative bleeding. This study was conducted to clarify the clinical features of NSAs and the results of early bypass and trapping. Nineteen ruptured NSAs were identified in 937 patients with subarachnoid hemorrhage (SAH). The principal treatment was to trap the aneurysm following bypass surgery as soon as possible after SAH onset. Angiography revealed nine BBAs and ten DAs. Eight patients (four BBA and four DA) were treated in the chronic stage because of delayed arrival (n = 3) or lack of aneurysm on initial angiography (n = 3), or other reasons (n = 2). The remaining 11 patients underwent early surgery using trapping after bypass, except for one BBA-type (clipped). During surgery, corresponding intraoperative findings were confirmed for each aneurysm type. There were six preoperative reruptures; five were determinant of patient outcome. In 14 patients without preoperative rerupture influencing outcome, 11 patients were independent at discharge and three patients dependent due to surgical complication. There was one case of minor intraoperative bleeding; no postoperative rerupture occurred. There was no delayed vasospasm-related deficit, although temporary symptomatic spasm occurred in three patients. Early bypass and trapping appeared to be an acceptable treatment strategy for these NSAs eliminating intra- and postoperative bleeding and not increasing a chance of delayed vasospasm.     

Subarachnoid hemorrhage caused by a dissecting aneurysm of the internal carotid artery: case report and review of the literature

A case of subarachnoid hemorrhage (SAH) resulting from a ruptured intracranial dissecting aneurysm of the internal carotid artery (ICA) is reported. A 58-year-old woman presented with headache and vomiting. A CT showed diffuse SAH. A cerebral angiography demonstrated a dissecting aneurysm at the C2 segment of the right ICA. In the present case, trapping with STA-MCA anastomosis was performed and the postoperative course was uneventful. Postoperative follow-up cerebral angiogram detected no aneurysm. SAH caused by the rupture of a dissecting aneurysm of the ICA has been considered rare. To our knowledge, there have been only 29 cases. We discuss the clinical characteristics with a review of the literature.     

Ruptured "blisterlike" aneurysm with a pseudoaneurysm formation requiring delayed intervention with endovascular coil embolization. Case report

A ruptured blisterlike aneurysm of the supraclinoid ICA rarely occurs. Nevertheless, it is recognized as a dangerous lesion because of the high risk of intraoperative bleeding associated with this lesion's wide fragile neck. There has been only one report of a blisterlike aneurysm treated by endosaccular packing after surgical wrapping. The authors describe the case of a ruptured blisterlike aneurysm with a pseudoaneurysm cavity, which was treated by coil embolization. This 63-year-old woman suffered a subarachnoid hemorrhage (SAH). Three cerebral aneurysms were identified on cerebral angiograms. A large saccular aneurysm at the ophthalmic portion of the right ICA was embolized with Guglielmi Detachable Coils (GDCs). Two small hemipherically shaped aneurysms on the C-2 and C-3 portions of the left ICA were observed conservatively. Thirteen days later, recurrent SAH was identified on computerized tomography scans. Angiography demonstrated the formation of a pseudoaneurysm from the aneurysm on the C-2 portion of the left ICA. Endosaccular embolization with GDCs was performed 40 days after admission. Disappearance of the pseudoaneurysm cavity and residual dome filling was seen immediately after the procedure. Follow-up angiography performed 9 months after embolization demonstrated complete obliteration of the aneurysm. This case illustrates that when treatment options for a blisterlike aneurysm with a pseudoaneurysm are unsuitable during the acute phase, coil embolization can be applied following progression of the lesion into a saccular aneurysm during the chronic stage.     

Ruptured intracranial dissecting aneurysms: management considerations with a focus on surgical and endovascular techniques to preserve arterial continuity

Background. The present retrospective analysis was undertaken to review an institutional experience with 13 intracranial dissecting aneurysms as source of subarachnoid haemorrhage (SAH) among a total of 585 ruptured intracranial aneurysms. Methods and results. In 6 patients the vertebral artery (VA) was affected, in 2 patients the basilar artery (BA), in 3 the internal carotid (ICA), in 1 the middle cerebral (MCA) and in 1 the postcommunicating (A2) segment of the anterior cerebral artery (ACA). Maintaining arterial patency was aimed at in all patients. Tangential clipping or circumferential wrapping were used as surgical methods. Endovascular stenting and/or coiling was applied in 2 instances. Four of the 6 VA dissecting aneurysms underwent surgical exploration between 1 and 22 days after haemorrhage. Two patients were in WFNS grade V and died subsequently with the aneurysms untreated, one after rehaemorrhage. In the patients with secured VA aneurysms the postoperative course was uncomplicated with the exception of additional caudal cranial nerve injury in 1 instance. Both BA aneurysms were initially treated by endovascular methods. In the first patient incomplete packing with Gugliemi detachable (GDC) coils was achieved. Follow-up angiography 6 months later showed growth and coil compaction and subsequent wrapping with Teflon fibres resulting in angiographic stabilization. The other BA aneurysm was treated by a combination of a coronary stent and GDC coils. The 3 dissecting ICA aneurysms were all explored surgically. In only 1 instance ICA continuity could be preserved by wrapping, in the other 2 cases a major portion of the vessel wall disintegrated upon removal of the surrounding clot. The only ACA dissecting aneurysm, on A2, was successfully treated with a Dacron cuff. In the single patient with a MCA aneurysm, a decision for conservative management was taken, because neither a surgical nor an endovascular solution was seen as a possibility that did not risk occlusion of lenticulostriate branches. The patient suffered a fatal rehaemorrhage 4 weeks later at her home. Conclusions. The reported experience suggests that in Western countries also dissecting aneurysms are an occasional source of SAH. The outcome in our conservatively managed patients confirms the poor prognosis of conservative management. Wrapping and endovascular stent based methods can achieve stabilization of the dissected artery without sacrificing the artery. Results of treatment appear to depend largely on the location of the dissecting aneurysm.     

Dissecting aneurysms of the vertebral artery: a management strategy

OBJECT: The authors present a retrospective analysis of their experience in the treatment of vertebral artery (VA) dissecting aneurysms and propose a management strategy for such aneurysms, with special emphasis on the most formidable VA dissecting aneurysms, which involve the origin of the posterior inferior cerebellar artery (PICA). METHODS: Since 1998, 18 patients with VA dissecting aneurysms, 11 of whom presented with subarachnoid hemorrhage (SAH), have been treated by endovascular surgery at the authors' institution. Obliteration of the entire segment of the dissected site with coils (internal trapping) was performed for aneurysms without involvement of the origin of the PICA (12 cases; among these the treatment-related morbidity rate was 16.7%). The treatment strategy applied to PICA-involved VA dissecting aneurysms presenting with SAH (three cases) included proximal occlusion of the parent artery followed by internal trapping of the aneurysm (one case), proximal occlusion of the parent artery followed by occipital artery (OA)-PICA bypass (one case), and two-staged internal trapping of the aneurysm involving double PICAs (one case). For PICA-involved VA dissecting aneurysms that were not associated with SAH at presentation (three cases), OA-PICA bypass was performed and followed by internal trapping of the aneurysm (two cases). In the remaining case in which a fetal-type posterior communicating artery was present, internal trapping was performed following successful balloon test occlusion (BTO). Overall, there was no sign of infarction in the PICA territory, despite complete occlusion of aneurysms involving the PICA. There was no recurrent bleeding or ischemic symptoms during the follow-up periods. The overall treatment-related morbidity rate for the VA dissecting aneurysms involving the PICA was 16.7%. CONCLUSIONS: Dissecting VA aneurysms that do not involve the PICA can be safely treated by internal trapping. For those lesions that do involve the PICA, a decision-making algorithm is advocated to maximize the efficacy of the treatment as well as to minimize the risks of treatment-related morbidity based on BTO.     

Endovascular management of dissecting vertebrobasilar artery aneurysms in patients presenting with acute subarachnoid hemorrhage

OBJECT: The authors report on a series of 29 patients presenting with acute subarachnoid hemorrhage (SAH) related to the rupture of a vertebrobasilar dissecting aneurysm. Special attention was focused on embolization techniques and immediate and midterm anatomical and clinical outcomes. METHODS: Between March 1994 and January 2003, 29 patients presented with acute SAH caused by the rupture of a vertebrobasilar dissecting aneurysm. Eleven patients (37.9%) had Hunt and Hess Grade I SAH, four (13.8%) Grade II, six (20.7%) Grade III, five (17.2%) Grade IV, and three (10.3%) Grade V. Aneurysms were classified into five groups based on lesion location, and treatment courses were decided. All patients except two were treated by endovascular trapping of the aneurysm with concomitant occlusion of the involved vertebral artery (VA). No technical or clinical complication was observed in 28 patients (97%). Aneurysm perforation occurred during the procedure in one patient (3%). There was evidence of aneurysm recanalization in one patient. One patient with Hunt and Hess Grade IV SAH and two patients with Grade V SAH died. One patient died of respiratory infection 1 year after aneurysm trapping. One patient presented with a recurrent hemorrhage 1 month after treatment and died. Overall morbidity and mortality rates were 13.8 and 17.2%, respectively. CONCLUSIONS: Twenty-nine patients with acute SAH due to rupturing of vertebrobasilar dissecting aneurysms were treated using endovascular techniques. In most cases, endovascular trapping of the aneurysm and concomitant occlusion of the VA was technically and clinically successful.     

Endovascular coil trapping for ruptured vertebral artery dissecting aneurysms by using double microcatheters technique in the acute stage

Summary ?Background. In the treatment of vertebral artery (VA) dissecting aneurysms, only proximal occlusion of the VA does not necessarily prevent rerupture. We evaluated the efficacy of coil trapping for the ruptured VA dissecting aneurysms using the double microcatheters technique. Methods. We treated 11 patients who presented with subarachnoid haemorrhage (SAH) due to rupture of a VA dissecting aneurysm which did not involve the posterior inferior cerebellar artery at the site of dissection. All patients tolerated the balloon occlusion test. Within 3 days of the SAH, the dissection site was trapped with a Guglielmi detachable coil (GDC) using the double microcatheters technique. The proximal and distal sites of the dissecting aneurysm were embolized simultaneously. Findings. GDC trapping at the affected site was successful in all 11 patients. Radiographic findings showed complete occlusion of the dissection site and patency of the unaffected artery. Although one patient experienced transient dysphagia, there were no major complications. Interpretation. The double microcatheters technique is effective for coil trapping of ruptured VA dissecting aneurysms in selected patients. The risks posed by this simple technique are minimal, even in the acute stage. Published online May 26, 2003     

Dissecting aneurysm of the intracranial vertebral artery associated with proximal focal degeneration of the elastica: a comparative pathological study of the vertebral artery in patients with and without aneurysms

BACKGROUND: The pathogenesis underlying intracranial dissecting aneurysms remains unclear. We performed a detailed study using vertebral artery specimens obtained at autopsy from patients with and without aneurysms to identify the primary abnormality resulting in weakness of the elastica. We compared our observations with those made in specimens manifesting the normal atherosclerotic process. METHODS: Using histologic methods, we examined intracranial vertebral artery specimens from two autopsied aneurysm patients and 13 autopsied control cases to compare the state of atherosclerosis and the weakness of the elastica at this aneurysm predilection site. RESULTS: Case 1: A 54-year-old woman with 2 dissecting aneurysms of the bilateral vertebral arteries (VA) who died from recurrent subarachnoid hemorrhage (SAH). Case 2: A 53-year-old woman who died from SAH. Microscopically, all 3 vertebral aneurysms were typical transmural dissecting aneurysms. They manifested areas of focal, severe degeneration of the elastic lamina and calcification at VA sites proximal to the aneurysms. These lesions could be differentiated from secondary changes attributable to the aneurysms because of their separate location only proximal to the site of aneurysmal rupture. Atherosclerotic changes were minimal in both cases. In the controls, the degenerative state of the elastic lamina of the VA reflected an atherosclerotic process. CONCLUSIONS: We postulate that focal degeneration of elastic tissue not involved in the atherosclerotic process was the vasculopathy resulting in aneurysm formation in our SAH cases.     

A case of traumatic dissecting aneurysm of the C1-2 portion of the internal carotid artery]

The authors report a case of traumatic dissecting aneurysm of the C1-2 portion of the internal carotid artery (ICA) in a 54-year-old woman. She suffered from traumatic SAH due to closed head trauma as a result of a motor vehicle accident. Twenty-five days after this accident, traumatic dissecting aneurysm of the C1-2 portion of the ICA that was caused by closed head trauma was ruptured and increased in size, as revealed by serial angiographic studies. In intraoperative finding, dissection involved the entire circumference of the C1-2 portion of the ICA. Clipping procedures were impossible, so internal carotid ligation and STA-MCA anastomosis was performed. To our knowledge, this traumatic dissecting aneurysm of the C1-2 portion of the ICA was the first case that presented with SAH. We discussed the mechanism of dissection of the ICA and operative strategy suitable for this aneurysm.     

Dissecting aneurysms of the intracranial vertebral artery

Among 86 patients with aneurysms arising from the vertebral artery or its branches, 24 had dissecting aneurysms. The patients with dissecting aneurysms were characteristically relatively young males. Twenty-one patients presented with subarachnoid hemorrhage (SAH) and three with ischemia. Severe headache or neck pain occurred in all three patients with ischemia. Five of the 21 patients with SAH and all three patients with ischemia experienced recurrent episodes. Angiography typically showed fusiform dilatation and proximal and/or distal narrowing of the affected artery. The difficulty of diagnosing this disorder is pointed out. Surgery was performed in 19 patients, the most common technique being clip-occlusion of the proximal vertebral artery. There were no postoperative deaths or rebleeding; a lateral medullary syndrome developed in three patients. The observation at surgery of intramural clot with characteristic discoloration was limited to the cases operated on within 36 days after the ictus. After this period, the aneurysm was whitish gray in color and had become firm. Of 36 other cases of vertebral dissecting aneurysm reported in the literature, 20 were operated on. The indications for surgery are discussed.     

Case of spontaneous bilateral VA dissecting aneurysm presenting with SAH

We report a case of bilateral vertebral artery (VA) dissecting aneurysm presenting subarachnoid hemorrhage (SAH). It was difficult to decide which side was responsible for SAH because the patient's symptom and head CT suggested that the left VA aneurysm had ruptured, but angiography and MRA showed an irregular pearl and string sign on the right side. He was successfully treated by trapping of the right VA dissecting aneurysm and we confirmed by intraoperative evaluation that the right VA dissecting aneurysm had ruptured. The left unruptured aneurysm decreased its size spontaneously. In the treatment of the bilateral VA dissecting aneurysms, angiography needs to be performed over and over again because contralateral unruptured aneurysm may grow or rupture due to increased hemodynamic stress. Various combinations of direct sugery with or without arterial reconstruction and endovascular treatment should be considered when treating bilateral VA dissecting aneurysms.     

Comparison between perimesencephalic nonaneurysmal subarachnoid hemorrhage and subarachnoid hemorrhage caused by posterior circulation aneurysms

OBJECT: Some authors have questioned the need to perform cerebral angiography in patients presenting with a benign clinical picture and a perimesencephalic pattern of subarachnoid hemorrhage (SAH) on initial computerized tomography (CT) scans, because the low probability of finding an aneurysm does not justify exposing patients to the risks of angiography. It has been stated, however, that ruptured posterior circulation aneurysms may present with a perimesencephalic SAH pattern in up to 10% of cases. The aim of the present study was twofold: to define the frequency of the perimesencephalic SAH pattern in the setting of ruptured posterior fossa aneurysms, and to determine whether this clinical syndrome and pattern of bleeding could be reliably and definitely distinguished from that of aneurysmal SAH. METHODS: Twenty-eight patients with ruptured posterior circulation aneurysms and 44 with nonaneurysmal perimesencephalic SAH were selected from a series of 408 consecutive patients with spontaneous SAH admitted to the authors' institution. The admission unenhanced CT scans were evaluated by a neuroradiologist in a blinded fashion and classified as revealing a perimesencephalic SAH or a nonperimesencephalic pattern of bleeding. Of the 28 patients with posterior circulation aneurysms, five whose grade was I according to the World Federation of Neurosurgical Societies scale were classified as having a perimesencephalic SAH pattern on the initial CT scan. The data show that the likelihood of finding an aneurysm on angiographic studies obtained in a patient with a perimesencephalic SAH pattern is 8.9%. Conversely, ruptured aneurysms of the posterior circulation present with an early perimesencephalic SAH pattern in 16.6% of cases. CONCLUSIONS: This study supports the impression that there is no completely sensitive and specific CT pattern for a nonaneurysmal SAH. In addition, the authors believe that there is no specific clinical syndrome that can differentiate patients who have a perimesencephalic SAH pattern caused by an aneurysm from those without aneurysms. Digital subtraction angiography continues to be the gold standard for the diagnosis of cerebral aneurysms and should be performed even in patients who have the characteristic perimesencephalic SAH pattern on admission CT scans.     

Urgent treatment of severe subarachnoid hemorrhage caused by ruptured traumatic aneurysm of the cavernous internal carotid artery using coil embolization followed by superficial temporal artery-middle cerebral artery anastomosis: a case report

BACKGROUND: Traumatic aneurysm of the cavernous internal carotid artery (ICA) with extension into the subarachnoid space is associated with increased risk of fatality especially when it is accompanied by severe subarachnoid hemorrhage (SAH). Only cases of patients who survived the acute stage and who were treated in a delayed setting have been reported. There has been no successfully treated case immediately after an injury. CASE DESCRIPTION: We encountered a 48-year-old man who presented with dense SAH immediately after being involved in a motor vehicle accident. Emergent angiography revealed traumatic aneurysm of the left cavernous ICA with extension beyond the superior wall of the cavernous sinus into the subarachnoid space and concomitant direct high-flow carotid cavernous fistula. Detachable platinum coil occlusion of the cavernous ICA followed by superficial temporal artery-middle cerebral artery anastomosis on day 0 and aggressive therapy to SAH, including ventriculocisternal irrigation and drainage, was performed. The patient eventually made a good recovery. CONCLUSION: Considering the extremely poor prognosis and unstable nature of a ruptured traumatic aneurysm with extensive SAH in the acute stage, definitive and immediate prevention of rebleeding in conjunction with proper revascularization would be warranted, such as in the present case.     

Blood blister-like aneurysms of the internal carotid artery trunk causing subarachnoid hemorrhage: treatment and outcome

OBJECT: The object of this study was to evaluate cases of subarachnoid hemorrhage (SAH) from ruptured blood blister-like aneurysms (BBAs) of the internal carotid artery (ICA) trunk. METHODS: The authors performed a single-center, retrospective study. Data analyzed were patient age, sex, Hunt and Hess grade, Fisher grade, time from SAH to hospitalization, aneurysm size and location, collateral capacity of the circle of Willis, time from hospitalization to aneurysm repair, type of aneurysm repair, complications, and Glasgow Outcome Scale (GOS) score at follow-up. RESULTS: A total of 211 patients suffered SAH from ICA aneurysms. Of these, 14 patients (6.6%) had ICA trunk BBAs; 6 men and 8 women. The median age was 47.8 years (range 29.9-67.7 years). The Hunt and Hess grade was IV or V in 7 cases, and SAH was Fisher Grade 3 + 4 in 6. All aneurysms were small (< 1 cm), without relation to vessel bifurcations, and usually located anteromedially on the ICA trunk. Three patients were treated with coil placement and 11 with clip placement. Of the 7 patients in whom the ICA was preserved, only 1 had poor outcome (GOS Score 2). In contrast, cerebral infarcts developed in all patients treated with ICA sacrifice, directly postoperatively in 2 and after delay in 5. Six patients died, 1 survived in poor condition (GOS Score 3; p < 0.001). CONCLUSIONS: Internal carotid BBAs are rare, small, and difficult to treat endovascularly, with only 2 of 14 patients successfully treated with coil placement. The BBAs rupture easily during surgery (ruptured in 6 of 11 surgical cases). Intraoperative aneurysm rupture invariably led to ICA trap ligation. Sacrifice of the ICA within 48 hours of an SAH led to very poor outcome, even in patients with adequate collateral capacity on preoperative angiograms, probably because of vasospasm-induced compromise of the cerebral collaterals.     

Large ophthalmic segment aneurysms with anterior optic pathway compression: assessment of anatomical and visual outcomes after endosaccular coil therapy

OBJECT: The optimal therapy for ophthalmic segment aneurysms with anterior optic pathway compression (AOPC) is undecided. Surgical results have been described, but the results of endovascular coil therapy have not been well documented. METHODS: The authors retrospectively reviewed data obtained in all patients who harbored unruptured ophthalmic segment aneurysms with AOPC who underwent endovascular coil therapy at their institution. They analyzed baseline and outcome visual function, aneurysm features, extent of aneurysm closure, internal carotid artery (ICA) occlusion, additional interventions, and neurological outcome. In 17 patients (16 women), age 38 to 83 years, there were 28 affected eyes. All aneurysms were greater than 10 mm in diameter. In the initial procedures 16 of 17 patients received endosaccular coils and the ICA was preserved; in one patient the aneurysm was trapped and the ICA occluded. Patients then underwent follow up for a mean of 2.90 years (range 1 month-1 1.2 years) after the last procedure. One patient died of subarachnoid hemorrhage (SAH) 1 month postoperatively and thus no follow-up data were available for this case. Vision worsened in six patients, stabilized in four, and improved in six. Twelve patients underwent 13 subsequent procedures, including endovascular ICA occlusion in seven, repeated coil therapy in five, and optic nerve decompression in one; vision improved in 83% of these cases after ICA occlusion. A second patient died of SAH 5 months after repeated coil treatment. At the final follow up, vision had improved in eight patients (50%), stabilized in four (25%), and worsened in four (25%). In 16 patients with follow-up studies, aneurysm closure was complete in eight (50%) and incomplete in eight (50%). CONCLUSIONS: The authors found that in patients with ophthalmic segment aneurysms causing chronic AOPC, endosaccular platinum coil therapy, with ICA preservation, may not benefit vision and that additional procedures may be needed. Evaluation of their results suggests that endovascular trapping of the aneurysm and sacrifice of the ICA appear to result in good visual, clinical, and anatomical outcomes.     

Intraoperative angiography during aneurysm surgery: a prospective evaluation of efficacy

OBJECT: Indications for intraoperative angiography during aneurysm surgery remain unclear. To define its use, the authors report the results of a prospective study in which this modality was used in all patients undergoing surgery for intracranial aneurysms. METHODS: Intraoperative angiography was performed prospectively in the surgical treatment of 517 consecutive aneurysms regardless of the lesion's location, size, or complexity. In 64 (12.4%) of 517 aneurysms intraoperative angiography findings prompted a change in surgical treatment. Residual aneurysm (47%) was the most frequent finding leading to clip revision. In 44% of cases, intraoperative angiography revealed vessel compromise. Surgery for aneurysms of the proximal internal carotid artery (ICA) was the most frequently altered, with lesions located at the superior hypophyseal artery (SHA) and clinoidal region having the highest revision rates, eight (40%) of 20 and eight (44%) of 18, respectively. Aneurysm size predicted the need for revision; giant aneurysms (> 24 mm) underwent revision in nine (29%) of 31 cases, whereas large aneurysms (15-24 mm) were revised in 12 (22%) of 54 cases. In a multivariate logistic regression model, factors related to increased revision rates included the SHA and clinoidal locations, as well as giant and large size. Ninety-five patients underwent both intraoperative and postoperative angiography. Five discrepancies were noted (95% accuracy); four were flow-related and one involved a previously unrecognized residual aneurysm. Complications attributable to intraoperative angiography occurred in 0.4% of cases. CONCLUSIONS: Proximal ICA location and large aneurysm size significantly predicted revision of surgery following intraoperative angiography. Unexpected findings, even in less complex locations, are frequently identified on intraoperative angiography. Low complication rates, high accuracy, and the unexpected need for clip readjustments favor a more widespread use of intraoperative angiography.     

Fusiform vertebral artery aneurysms as a cause of dissecting aneurysms. Report of two autopsy cases and a review of the literature.

Two autopsy cases of angiographically determined fusiform aneurysms of the vertebral arteries (VAs) are reported and the appropriate literature is reviewed to investigate the pathological characteristics of both fusiform and dissecting VA aneurysms and the pathogenesis of dissecting aneurysms. One patient had suffered a subarachnoid hemorrhage (SAH) due to dissection of a previously documented incidental fusiform aneurysm. The other patient had harbored incidental fusiform aneurysms coexistent with a ruptured aneurysm of the posterior inferior cerebellar artery. The location and pathological features of the aneurysms were similar in the two cases. The aneurysms in both cases displayed intimal thickening, disruption of the internal elastic lamina, and degeneration of the media. A mural hemorrhage and patchy calcification were also found in the case that included SAH. Based on their pathological investigation of these two cases and a review of reported cases, the authors propose that incidental fusiform aneurysms in the VAs are characterized by weakness in the internal elastic lamina and, therefore, have the potential to become dissecting aneurysms, resulting in a fatal prognosis. This suggests that long-term control of blood pressure is mandatory in patients with incidental fusiform aneurysms in the VAs.     

Dissecting posterior inferior cerebellar artery aneurysm presenting with subarachnoid hemorrhage right after anticoagulant and antiplatelet therapy against ischemic event

BACKGROUND: Dissecting aneurysms with initial ischemic manifestations may present with subsequent subarachnoid hemorrhage (SAH), and their treatment is controversial. This is a case report that illustrates the dilemma when dealing with an immediate post-SAH period dissecting posterior inferior cerebellar artery (PICA) aneurysm initially presenting with an ischemic event. METHODS: We present a 57-year-old man with a dissecting PICA aneurysm who had SAH right after anticoagulant and antiplatelet therapy for cerebral infarction. The aneurysm was not detected by magnetic resonance angiography performed at the time of admission. RESULTS: On admission, he was treated with both anticoagulant and antiplatelet therapy. After the SAH episode, he underwent emergent resection of the dissecting aneurysm and left OA-PICA anastomosis. CONCLUSION: If hemorrhagic transformation occurs at the site of an ischemic dissecting aneurysm, surgical or endovascular intervention should be considered immediately. Although the optimal treatment of dissecting aneurysms with ischemic onset remains controversial, anticoagulant and antiplatelet therapy should not be rejected out of hand.