Aneurysmal remnants after microsurgical clipping: classification and results from a prospective angiographic study (in a consecutive series of 305 operated intracranial aneurysms)

The aim of this prospective study, carried out in a consecutive series of 305 microsurgically clipped aneurysms, was to check the absence of an aneurysmal remnant on post-operative angiography, and if a remnant was found to quantify its size in order to consider additional clipping to avoid the risk of rebleeding. Out of the 305 aneurysms, 292 (96%) were located in the anterior and 13 (4%) in the posterior circulation. Post-operative angiography was performed on average two weeks after surgery. Determination of the presence or not of an aneurysmal remnant and its quantification was done by an independent observer (JCA). Aneurysmal remnants were classified into 5 grades: grade I: less than 50% of neck size, grade II: more than 50% of neck size, grade III: residual lobe of a multilobulated sac, grade IV: residual sac of less than 75% of aneurysmal size and grade V: residual sac of more than 75% of aneurysmal size. Correlations between presence (and size) of the remnant and anatomical-surgical data obtained from the operative report were studied. Clipping was considered incomplete in 18 of the 305 aneurysms (5.9%). The group with residual neck only (grade I = 8 cases, Grade II = 4 cases) amounted to 4% of the whole series, whereas the group with residual neck + sac (grade III = 4, grade IV = 1, Grade V = 1) to 1.9%. Only this latter group was amenable to re-operation for complementary clipping without creating a stenosis of the parent artery. Our results are in the range of those of other published series. Anatomical-surgical factors for predisposition to incomplete clipping are discussed. The rates of sac obliteration using microsurgical clipping are to be compared with those recently achieved by electrically detachable coiling. The classification which we have developed is proposed for future comparison with endovascular results.     

Endovascular treatment of abdominal aortic aneurysms. Morphology of aneurysms as one of the deciding indicating factors

Endovascular treatment of aneurysms of the abdominal aorta is based on intravascular bridging of the aneurysm using of an endovascular prosthesis. The prosthesis must be safely anchored above and below the sac of the aneurysm in the non-dilated artery. Therefore the indication of endovascular treatment depends on the morphology of the aneurysm. The objective of the work was to analyse the morphology of the aneurysm with regard to the possibility of endovascular treatment. The morphology of the aneurysm was evaluated with regard to the angiographic examination and examination by computed tomography. The following parameters were investigated: diameter and length of the proximal and distal neck, diameter of the sac in two planes, diameter and tortousity of the iliac arteries, tortousity of the infrarenal aorta. A total of 70 patients with aneurysms of the abdominal aorta were examined. The patients were divided into three groups according to the morphology of the aneurysm. I. infrarenal aneurysms not affecting common iliac artery (n = 20) 28.5%, II. infrarenal aneurysms affecting common iliac artery (n = 38) 54.2%, III. juxtarenal aneurysms regardless of the affection of common iliac arteries (n = 12) 17.1%. Of the total of 70 examined patients 24 (34.2%) with infrarenal aneurysm and 6 (8.57%) with juxtarenal aneurysm were suitable for endovascular treatment.     

Partial thrombosis of canine carotid bifurcation aneurysms with cellulose acetate polymer

OBJECTIVE: To investigate the usefulness of a cellulose acetate polymer (CAP) solution for partial thrombosis of aneurysms. METHODS: We created 14 canine cervical carotid bifurcation aneurysms, 11 of which were subsequently thrombosed partially with CAP solution. We then conducted angiographic and histological investigations. RESULTS: Nine aneurysms were thrombosed 50 to 70% by volume, although a significant crescent crevice between the aneurysmal sac and the CAP mass was left in four of the aneurysms. In the remaining two aneurysms in which a crescent crevice had been seen in the initial stage of CAP injection, 80% and more than 95% thrombosis were needed to occlude the crevice, respectively. Follow-up angiograms of the seven aneurysms with no crescent crevice revealed no shifts of position of the CAP mass toward the bottom of the aneurysm sac, but slight ballooning of the remnants was observed in two of them. The angiograms of the other four aneurysms with significant crescent crevices demonstrated rupture with a massive hematoma in one and shifts of the CAP mass with marked enlargement of remnants in three. Histologically, the seven aneurysms with no enlarged remnants had newly developed membranes consisting of endothelium, infiltrated spindle-shaped cells, collagen, and elastic fibers. In contrast, in the three markedly enlarged aneurysms, there were only recent clots between the CAP mass and the aneurysm lumen and no development of endothelium. CONCLUSION: Partial thrombosis with CAP solution is useful to keep aneurysms in a stable configuration, unless a crescent crevice has been left.     

Runt determines cell fates in the Drosophila embryonic CNS

BACKGROUND AND PURPOSE: Our purpose was to evaluate the ability of transcranial color-coded Doppler sonography (TCCD) to 1) identify Guglielmi detachable coils (GDCs) within intracranial aneurysms, 2) show endovascular aneurysmal occlusion and patency of parent and branch arteries, 3) determine the flow velocities within parent arteries and major branches before and after treatment, and 4) assess persistence of aneurysmal occlusion. METHODS: The sonographic appearance of GDCs was established experimentally by TCCD (2 to 2.5 MHz), which was then performed in 40 patients with 43 aneurysms occluded by GDCs. The patency of parent arteries and major branches was assessed qualitatively and compared with the immediate posttherapeutic angiographic appearance in every patient. Flow velocities were selectively measured and compared before and after treatment in 21 parent arteries and 24 major branches. Follow-up TCCD studies performed in 26 patients were compared with angiographic (16 cases) and MR angiographic (10 cases) findings for signs of recanalization of the treated aneurysms. RESULTS: The GDCs were identified experimentally and in the patients as hyperechoic structures of the size and shape, and in the location of, the treated aneurysm in 41 of 43 cases. TCCD in accordance with angiography showed a lack of flow in 42 aneurysms and the presence of flow signal in one large aneurysm. Patency of the parent artery was shown in 40 aneurysms and in all branches. Follow-up TCCD showed the coils unchanged in 23 of 26 cases. In three large aneurysms, TCCD indicated recanalization and reappearance of a flow signal separate from the parent artery. CONCLUSION: TCCD is a reliable, noninvasive means to assess parent artery and major branch patency and to reveal a lack of hemodynamic compromise in the vicinity of aneurysms after endovascular therapy. On follow-up examinations, TCCD was able to detect signs of aneurysmal recanalization.     

Complex intracranial aneurysms: combined operative and endovascular approaches

OBJECTIVE: Endovascular management of complex intracranial aneurysms is increasingly being considered as an alternative to standard surgical clipping. However, little attention has been paid to the complementary nature of surgery and endovascular therapy. METHODS: Between September 1992 and May 1997, 12 patients with complex intracranial aneurysms were treated with combined operative and endovascular methods. Seven patients demonstrated subarachnoid hemorrhage (two of Grade II, two of Grade III, and three of Grade IV). Five patients demonstrated unruptured aneurysms, i.e., three giant aneurysms (one vertebrobasilar junction aneurysm, one middle cerebral artery bifurcation aneurysm, and one internal carotid artery-ophthalmic artery aneurysm), one large internal carotid artery-ophthalmic artery aneurysm, and one middle cerebral artery serpentine aneurysm. Management strategies involved either surgery followed by endovascular therapy (S-E; n = 5) or endovascular therapy followed by surgery (E-S; n = 7). S-E paradigms included aneurysm exploration followed by endovascular treatment (S-E1; n = 3), partial aneurysm clipping followed by endovascular aneurysm packing (S-E2; n = 1), and extracranial-to-intracranial bypass followed by endovascular parent vessel occlusion (S-E3; n = 1). E-S paradigms included superselective angiography followed by surgical clipping (E-S1; n = 2), Guglielmi detachable coil partial dome packing followed by delayed surgical clipping (E-S2; n = 2), proximal temporary vessel balloon occlusion followed by aneurysm clipping (E-S3; n = 2), and proximal permanent vessel occlusion followed by surgical aneurysm decompression for mass effect treatment (E-S4; n = 1). RESULTS: Eleven aneurysms (92%) were completely eliminated. The remaining aneurysm was 90% obliterated and remained quiescent at the 34-month follow-up examination, despite presenting with subarachnoid hemorrhage. No patient experienced repeat bleeding (follow-up period, 23+/-28 mo). There were no deaths. One patient achieved a fair outcome (Glasgow Outcome Scale score of III); all other patients experienced excellent outcomes (Glasgow Outcome Scale score of I). In all cases, the aneurysm management paradigm chosen had a positive effect on definitive therapy. CONCLUSION: Several factors can contribute to the complexity of intracranial aneurysms. Management strategies that combine operative and endovascular techniques in a complementary way, for the best possible outcomes for these patients, can be designed accordingly.     

Surgical results and the related topographic anatomy in paraclinoid internal carotid artery aneurysms

Paraclinoid internal carotid artery aneurysms arising between the roof of the cavernous sinus and the origin of the posterior communicating artery are of considerable interest with regard to their anatomical variations and technical surgical challenges. Twenty-seven patients with 30 paraclinoid aneurysms were treated surgically through pterional intradural approach. Neck clipping was performed in 22 (73%) of the 30 aneurysms, coating in seven, and trapping in one. The surgical outcome was excellent in 24 patients (24/27, 89%), with two patients showing ipsilateral partial visual field defect (2/27, 7%). There was one death (4%) due to infarction after unintended carotid artery trapping. The characteristic topographic anatomical features which we considered to pose technical difficulties and to be responsible for the complications or failure in neck clipping were aneurysmal dome extending into the anterior clinoid process, atheroma at the neck, multiple paraclinoid aneurysms, ophthalmic artery originating at the neck, and marked supero-medial shift of the C2 segment of the carotid artery. pre-operative depiction of the topographical anatomy around the paraclinoid aneurysm is essential but not always possible on the basis of conventional angiography. Magnetic resonance or three-dimensional computerized tomographic angiography, and their axial source imaging, were useful in delineating the topography with unusual aneurysmal growth, overlap of aneurysm with the parent artery, and uncommon variations of the surrounding structures.     

Abdominal aortic aneurysms in sheep: prevention of rupture with endoluminal stent-grafts

PURPOSE: The authors evaluated the ability of an aortic balloon-expandable endovascular stent-graft to prevent rupture in a model of spontaneously rupturing abdominal aortic aneurysms in sheep. MATERIALS AND METHODS: Aneurysms were created in 16 sheep by inserting a 60 x 18-mm segment of the left internal jugular vein, end-to-end anastomosed, to the sectioned infrarenal abdominal aorta. The sheep were randomly assigned into two groups; eight animals underwent endovascular implantation of an 80 x 12-mm balloon expandable stent-graft (group A), and eight were only followed up (group B). RESULTS: In group B, seven of eight animals had died of aneurysmal rupture by 3 months. In group A, six of the eight aortic aneurysms were immediately excluded, and six animals were alive at 3 months without rupture. The 3-month survival rate was 100% in group A and 12% in group B (P = .0023). Macro- and microscopic analysis of the section of the aorta in which the stent-graft had been placed revealed rapid retraction of the aneurysmal sac. CONCLUSION: Placement of an endovascular stent-graft induced regression of a branchless aneurysm and prevented rupture.     

Multiple pregnancy and microelements: zinc (preliminary report)

Incidence, causes and results of permanent ICA clipping during arterial cerebral aneurysm surgery were analyzed in randomized group of 470 patients. Permanent ICA clipping was performed in 6 cases (1.3% of all surgeries). The causes of permanent ICA clipping were ICA wall rupture in 4 (0.9%) cases, bleeding from aneurysms of the ophthalmic segment of the internal carotid artery (ICA) in 2 (0.4%). Atherosclerotic changes of ICA were found and verified by biopsy in all cases of ICA rupture. Two variants of rupture were identified. ICA aneurysm avulsion from the artery in the area of aneurysmal neck with vascular wall defect development in 2 (0.6%) cases; in the second variant, ICA rupture was caused by frontal lobe traction. In the study group aneurysms of ophthalmic segment of ICA were found in 19 cases: intraoperative bleeding rate was 31% (6 cases). ICA was clipped in 33% of all cases of intraoperative bleeding. Among 6 patients with permanent ICA clipping, 5 died. Deaths were caused by cerebral infarction in 4 cases and acute blood loss in 1 case.     

Endosaccular occlusion of basilar artery bifurcation aneurysms using electrically detachable coils

Thirteen patients with basilar artery bifurcation aneurysms, treated by electrothrombosis using electrically detachable coils, are presented. Nine of them presented after hemorrhage, two with mass effect, and two were found coincidentally with other ruptured aneurysms. Selection for endovascular therapy was based on the following criteria: 1) poor clinical condition (Hunt and Hess III-V); 2) high surgical risk; 3) age and poor medical condition; 4) morphological features (small necked aneurysms). With endovascular Guglielmi detachable coils aneurysm occlusion ranging from 70-100% was achieved in all cases. All five small necked and two large broad necked aneurysms were totally occluded. Two large aneurysms had a 95% occlusion and two other large aneurysms were 90% occluded. In another patient with a large broad based aneurysm only an 80% occlusion was achieved, because of tortuosity of the vertebrobasilar system. Our last patient, who presented as grade V clinically, was partially treated with a 70% aneurysmal occlusion. The clinical results were excellent in 10 and good in 2. The only poor outcome was seen in the grade V patient. There was no morbidity or mortality related to therapy. The only complication was an asymptomatic dissecting aneurysm at the origin of the vertebral artery. Angiographic follow up time ranged from 6 to 20 months with a mean of 9 months. Four patients were treated too recently to have their angiographic follow up at 6 months. Two patients were lost to follow up. Clinical follow up ranged from 1 to 17 months with a mean of 8.9 months. The analysis of our cases clearly shows that aneurysms, which were densely packed with coils, especially if small necked, were less likely to be reperfused and showed a longlasting stable result. Large broad based aneurysms were more likely to be reopened by blood flow after the first procedure, especially if loosely filled with coils, and needed up to 3 interventions to achieve a satisfying result, whereas later in the series a high percentage rate of occlusion was seen after the first procedure. We consider now also a less than 100% occlusion acceptable, because most of the aneurysms will rupture at the dome, which was occluded in all our cases. We conclude, that this new endovascular method is a viable alternative in the treatment of posterior circulation aneurysms with a high surgical risk, in old patients and those in poor clinical and medical condition.     

MR angiography with ultrashort echo time in cerebral aneurysms treated with Guglielmi detachable coils

We evaluated a time-of-flight three-dimensional MR angiographic sequence with an ultrashort echo time for its ability to characterize the perfusional state of cerebral aneurysms that had been treated with Guglielmi detachable coils and to depict adjacent cerebral arteries. The results were compared with findings at conventional MR angiography and digital subtraction angiography. Adjacent vessels were seen better in 36% of patients imaged with the new technique. Both MR angiographic methods detected residual cerebral aneurysmal perfusion with a tendency to overestimate the patent portion of the aneurysm.     

The microsurgical treatment of large and giant aneurysms of the internal carotid artery located parasphenoidally

Internal carotid aneurysms in the ophthalmic area presents a challenge in cerebrovascular neurosurgery. The study was undertaken to provide evidence for the application of intravascular aspiration during direct surgical interventions and to outline their variants used at the N. N. Burdenko Institute of Neurosurgery. The study included 4 (3 females and 1 male) patients with large and giant internal carotid aneurysms of parasphenoidal site who were treated at the Institute. Clipping of the aneurysmal neck was made by employing intravascular blood aspiration from the aneurysm. The technique proved to be effective in proximal monitoring the carotid artery at surgery. It substantially reduced aneurysmal blood flow and wall tension, thus favouring aneurysmal dissection to make clipping.     

Neurosurgical management of cerebral aneurysms following unsuccessful or incomplete endovascular embolization

Modern endovascular techniques permit treatment of intracranial aneurysms in many circumstances when surgery is associated with significant morbidity. Occasionally, embolization of aneurysms is unsuccessful or incomplete or followed by complications, in which case surgical management is required. Since 1986, 196 patients have undergone embolization of intracranial aneurysms at the authors' institution and 21 (11%) required subsequent surgical treatment. Attempted embolization failed in five patients (Group A). Ten patients (Group B) had only partial occlusion of the aneurysm or demonstrated recanalization on follow-up studies. Eight of these Group B patients underwent embolization with Guglielmi detachable coils (GDCs), representing 5.7% of the 141 GDC-treated patients in this experience. Surgical treatment in these two groups consisted of clipping (eight cases), surgical parent vessel occlusion (one case), and parent vessel occlusion with extracranial-intracranial bypass (six cases). Fourteen (93%) of the 15 patients in these two groups had an excellent or good outcome with complete aneurysm occlusion. Six patients underwent surgery to treat complications related to the endovascular procedure (Group C). Of these, four patients had neurological improvement compared to their preoperative state, and two died. This series of cases demonstrates that surgical treatment of aneurysms is usually possible with good results following incomplete embolization and emphasizes the need for close and continued neurosurgical involvement in the endovascular management of intracranial aneurysms.     

Canine fucosidosis: a model for retroviral gene transfer into haematopoietic stem cells

To investigate the role of endovascular treatment we performed a retrospective study of our patients with multiple intracranial aneurysms seen in our institution between October 1992 and March 1995. This period was chosen to study a homogeneous group of patients since the appearance of controlled detachable coils, and to obtain the largest number of patients with angiographic follow-up of the aneurysms treated. We studied 53 patients with a total of 128 aneurysms, in 46 of whom we treated 67 aneurysms by the endovascular approach. Of these, 5 aneurysms in 3 patients were treated by occlusion of the parent vessel and 62 aneurysms in 43 patients with coils, 52 with Guglielmi detachable coils and 10 with mechanically detachable spirals. Complete occlusion was obtained in 58 aneurysms, and partial occlusion in 9. The therapy caused permanent neurological deficit in 3 cases (6.5%), and there was 1 case of rebleeding (incomplete occlusion of the aneurysm). No deaths occurred. All aneurysms were treated in 29 of the 53 patients. Endovascular procedures were used for 16 patients (30%), surgery was performed in 1 patient (2%) and the two were combined in 12 (23%). In 23 of 53 cases (43%), unruptured aneurysms were left untreated, usually because of their small size. In 1 patient with unruptured aneurysms, the endovascular approach failed and the patient refused surgery.     

A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneurysms

BACKGROUND: The treatment of giant and large paraclinoid aneurysms remains challenging. To improve exposure, facilitate the dissection of aneurysms, assure vascular control, reduce brain retraction and temporary occlusion time, enable simultaneous treatment of associated lesions, and achieve more successful treatment of "difficult" (atherosclerotic and calcified) aneurysms, we combined the skull-base approach with endovascular balloon occlusion of the internal carotid artery (ICA) and suction decompression of the aneurysm. METHODS: Sixteen female patients were treated, eight with giant aneurysms and eight with large aneurysms. Eight aneurysms occurred on the right side and eight on the left. Eight patients had an additional aneurysm; five were clipped during the same procedure. Three patients had infundibular arterial dilation. One patient had an associated hemangioma of the ipsilateral cavernous sinus. The cranio-orbital-zygomatic approach was used for all patients. The anterior clinoid was drilled, and the optic nerve was decompressed, dissected, and mobilized. Transfemoral temporary balloon occlusion of the ICA in the neck was followed by placement of a temporary clip proximal to the posterior communicating artery. Suction decompression was then applied. All aneurysms were then successfully clipped, except one that had a calcified neck and wall that could not be collapsed. Intraoperative angiography performed in 13 of 15 patients with clipped aneurysms confirmed obliteration of the aneurysm and patency of the blood vessels. RESULTS: Postoperative results were good in 14 patients. One patient had right-sided hemiplegia and expressive aphasia, which improved after rehabilitation. One patient with an additional basilar tip aneurysm clipped simultaneously died on the fifth postoperative day because of intraventricular hemorrhage. The origin of bleeding could not be determined on autopsy. Surgical difficulties and morbidity stemmed mainly from a severely calcified or atherosclerotic aneurysmal neck. CONCLUSION: The combination of skull-base approaches and endovascular balloon occlusion coupled with suction decompression is a successful option for the treatment of these challenging aneurysms.     

Safety and efficacy of endovascular treatment of acutely ruptured aneurysms

OBJECTIVE: To study the safety and efficacy of endovascular treatment of acutely ruptured aneurysms with Guglielmi detachable coils. METHODS: From August 1992 until December 1995, 75 patients were referred for endovascular treatment of acutely ruptured aneurysms. There were 49 women and 26 men, with a mean age of 55 years. Patients were classified according to the Hunt and Hess grading system. There were 18 Grade I patients (24%), 13 Grade II patients (17%), 30 Grade III patients (40%), 11 Grade IV patients (15%), and 3 Grade V patients (4%). Fifty patients (66%) were treated within 48 hours, and 64 (85%) were treated within 1 week of hemorrhage. The most frequently treated aneurysms were located at the basilar bifurcation (32%), anterior communicating artery (16%), posterior communicating artery (15%), and ophthalmic segment of the carotid artery (11%). Most of the aneurysms were smaller than 15 mm (77%). Fifty-six percent of the aneurysms had small (4 mm) necks, and 44% had wide (> 4 mm) necks. Clinical follow-up was performed at 6 months, and results were classified according to the Glasgow Outcome Scale (GOS). Control angiograms were performed immediately, at 6 months, and yearly thereafter. RESULTS: Immediate angiographic results were considered to be satisfactory in 58 patients (77%) (complete obliteration, 40%; residual neck and dog ear, 37%). Technical failures occurred in 5 patients (7%), and 12 patients experienced some residual opacification of their aneurysms (16%). The procedure-related mortality and morbidity rate was 8%. At 6 months, the outcomes were as follows: GOS score of 1, 50 patients (66.7%); GOS score of 2, 4 patients (5.3%); GOS score of 3, 4 patients (5.3%); and GOS score of 5, 17 patients (22.7%). The main causes of death and disability at 6 months were the direct effect of the initial hemorrhage (9%), delayed ischemia (6.7%), subsequent bleeding (4%), intraprocedural rupture (4%), open surgical complications (3%), and unrelated deaths (4%). Six-month angiographic follow-up data were available for 50 patients (67%). The morphological results were considered to be satisfactory in 44 of these 50 patients (88%) (complete occlusion, 46%; residual neck or dog ear, 42%). CONCLUSION: Endovascular treatment of acutely ruptured aneurysms was attempted without clinically significant complication in 92% of the patients. The morphological results were unsatisfactory in 23% of the patients. Complete obliteration of the sac, with or without residual neck, is essential to prevent subsequent bleeding, which occurred in 5% of the patients. The overall outcome at 6 months was similar to that of surgical series, despite a selected group of patients with negative prognostic factors.     

Treatment of intracranial aneurysm in interventional neuroradiology. What problems for the anesthetist?

AIM: To outline the most occurring complications during endovascular treatment of intracranial aneurysms. DESIGN: Retrospective review of thirty-four patients treated from October 1994 to February 1996 with the placement of mechanically detachable microcoils inside the aneurysmal sac. SETTING: Interventional neuroradiology suite equipped for anesthetic care. PATIENTS: Thirty-four patients with ruptured (88%) or unruptured (12%) intracranial aneurysm submitted to elective (38%) or emergency (62%) endovascular treatment. Aneurysms were located in the anterior circulation in twenty-six patients (76%) and in the posterior circulation in eight patients (24%). INTERVENTIONS: A microcatheter was introduced into the arterial cerebral circulation to deliver tungsten microcoils to aneurysmal sac. The transfemoral approach was used in most cases. All patients were treated under general anesthesia with tracheal intubation, conventional mechanical ventilation and neuromuscular blockade. The procedure was performed under anticoagulation with heparin and intravenous nimodipine administration. MEASUREMENTS: Neurological assessment was performed at the time of treatment (H&H 1) and six hours after the end of intervention (H&H 2) using Hunt and Hess classification system. The outcome was scored at four weeks following treatment using Glasgow Outcome Scale (GOS). RESULTS: Twenty-two (65%) interventions were successful. Attempted embolization failed in twelve (35%) patients due to intraoperative complications (17.6%) or technical difficulties (17.6%). Failures were more frequently determinated by vasospasm and haemorrhage. CONCLUSIONS: The time of intervention, the use of heparin and the patient medical conditions need to be considered in preventing the complications of endovascular treatment.     

Arteriography using helicoidal computerized tomography in the study of complex aneurysms of the circle of Willis

INTRODUCTION: Computed tomography angiography (CTA) can add information to digital subtraction angiography (DSA) in selected cases of aneurysms of the circle of Willis. CLINICAL CASES: 1. Patient with progressive visual loss and headache. CT and DSA showed an image of partially thrombosed suprasellar aneurysm. CTA better defined the relationship between the lesion and regional vessels. 2. Woman with subarachnoid hemorrhage (SAH). CTA defined the aneurysmal neck and its relationship to the clinoid process. 3. Man with SAH, CT and DSA showed an arteriovenous malformation and three arterial aneurysms one of which was in a tortuous vessel. CTA confirmed digital angiographic data. CONCLUSION: CTA is a new image technique that can either add or confirm DSA findings in complex aneurysms of the circle of Willis.     

Tooth structure loss apical to preparations for fixed partial dentures when using self-limiting burs

BACKGROUND: Endovascular treatment of cerebral aneurysms is a relatively new method, since only a few animal models and data are available. The present experimental study was performed in order to establish an appropriate aneurysm animal model, to determine the rate of permanent occlusion, and to correlate radiologic and morphologic findings. METHODS: End-to-side anastomoses of both common carotid arteries were performed microsurgically in 53 chinchilla rabbits. Venous pouches were adapted into the newly created bifurcation, resulting in berry-shaped aneurysms comparable to those in humans with regard to size and hemodynamics. Platinum and tungsten coils were used for endovascular embolization. The embolized aneurysms were investigated radiologically and morphologically. RESULTS: Twenty-three carotid bifurcation aneurysms remained for testing endovascular therapeutic approaches. The morphologic examinations of 13 embolized aneurysms revealed in no instance a complete obliteration, even in the three cases that were considered completely embolized according to angiographic criteria. CONCLUSIONS: The present animal model is an optimal tool for endovascular research. Analysis of the results of coil obliteration revealed a considerable discrepancy between radiologic and pathologic findings. The radiologic degree of aneurysm occlusion was overestimated.     

Experience with computed tomographic angiography for the detection of intracranial aneurysms in the setting of acute subarachnoid hemorrhage

OBJECTIVE: To objectively compare computed tomographic angiography (CTA) with selective digital subtraction angiography (DSA) in the detection and anatomic definition of intracranial aneurysms, particularly in the setting of acute subarachnoid hemorrhage (SAH). METHODS: In a blinded prospective study, 40 patients with known or suspected intracranial saccular aneurysms underwent both CTA and DSA, including 32 consecutive patients with SAH in whom CTA was performed after CT images were obtained diagnostic for SAH. The CT angiograms were interpreted for presence, location, and size of the aneurysms, and anatomic features, such as the number of aneurysms lobes, aneurysm neck size (< or = 4 mm), and the number of adjacent arterial branches were suggested. The images obtained with CTA were then compared with the images obtained with DSA, with the later images serving as controls. RESULTS: DSA revealed 43 aneurysms in 30 patients and ruled out intracranial aneurysms in the remaining 10 patients. For aneurysm presence alone, the sensitivity and specificity for CTA was 86 and 90%, respectively. For the presence of an aneurysms, six CT angiogram showed false negative results and one CT angiogram showed a false positive result. False negative results were usually caused by technical problems with the image, tiny aneurysm domes (< 3 mm), and unusual aneurysm locations (i.e., intracavernous carotid or posterior inferior cerebellar artery aneurysms). The results obtained with CTA were, compared with the results obtained with DSA, more than 95% accurate in determining dome and neck size of aneurysm, aneurysm lobularity, and the presence and number of adjacent arterial branches. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning. CONCLUSION: CTA is useful for rapid and relatively noninvasive detection of aneurysms in common locations, and the anatomic information provided in images showing positive results is at least equivalent to that provided by DSA. In cases of SAH in which the nonaugmented CT and CTA results indicate a clear source of bleeding and provide adequate anatomic detail, we think it is possible to forego DSA before urgent early aneurysm surgery. In all other cases, DSA is indicated.     

False aneurysm of the left ventricle and coronary aneurysms in Beh?et disease

A false left ventricular aneurysm and coronary artery aneurysm were discovered in a 29 year old patient with Beh?et's syndrome. The operation under cardiopulmonary bypass consisted of closing the neck of the false aneurysm by an endo-aneurysmal approach with a Gore-Tex patch. The coronary artery aneurysms were respected. There were no postoperative complications. Cardiac involvement is rare in Beh?et's syndrome (6%). The originality of this case is the association of two aneurysmal pathologies: the coronary and ventricular aneurysms due to the angiitis and the myocardial fragility induced by ischaemia.