Outcomes after cerebral aneurysm clip occlusion in the United States: the need for evidence-based hospital referral

2003 ◽  
Vol 99 (6) ◽  
pp. 947-952 ◽  
Author(s):  
John A. Cowan ◽  
Justin B. Dimick ◽  
Reid M. Wainess ◽  
Gilbert R. Upchurch ◽  
B. Gregory Thompson

Object. In an age of multimodality and multidisciplinary treatment of cerebral aneurysms, patient outcomes have improved significantly. For a number of complex surgical procedures, hospitals with high case volumes yield superior outcomes. The effect of hospital volume on the mortality rate after emergency and elective cerebral aneurysm clip occlusion in a nationally representative sample of patients is unknown. Methods. Using clinical data derived from the Nationwide Inpatient Sample for the years from 1995 through 1999, 12,023 patients who underwent clip occlusion of a cerebral aneurysm (International Classification of Diseases, Ninth Revision, Clinical Modification code 3951) were included. Patient age, comorbid conditions, nature of admission, and diagnosis of subarachnoid hemorrhage were abstracted. Hospital case volume was grouped into quartiles. Unadjusted and case-mix adjusted analyses were performed. The mean patient age was 53.2 ± 13.5 years. The overall crude postoperative mortality rates for emergency and elective aneurysm clip occlusion were 12.2 and 6.6%, respectively. Very low volume hospitals demonstrated higher mortality rates than very high volume hospitals for both emergency (14.7 compared with 8.9%, p < 0.001) and elective (9.4 compared with 4.5%, p < 0.001) aneurysm surgery. Patient-specific predictors of death in the multivariate model were renal disease (odds ratio [OR] 3.32, p < 0.042); age (> 60 years, OR 2.36, p < 0.001; 51–60 years, OR 1.63, p < 0.001; 40–50 years, OR 1.25, p = 0.047); chronic obstructive pulmonary disease (present, OR 1.52, p < 0.001); and nature of admission (emergency, OR 1.18, p = 0.03). Provider-specific predictors of death included very low volume (OR 1.59, p < 0.001); low-volume (OR 1.37, p = 0.001); and high-volume (OR 1.45, p < 0.001) hospitals compared with very high volume hospitals. Conclusions. A significant volume—outcome effect exists for surgical treatment of cerebral aneurysms in the US. Factors influencing this effect should be investigated to guide future healthcare policy and evidence-based referral. Whenever possible, healthcare practitioners should refer patients to centers in which superior outcomes are consistently demonstrated.

1995 ◽  
Vol 82 (2) ◽  
pp. 294-295 ◽  
Author(s):  
Alan Turtz ◽  
David Allen ◽  
Robert Koenigsberg ◽  
H. Warren Goldman

✓ The use of magnetic resonance (MR) angiography as a safe, accurate, and reliable substitute for invasive cerebral arteriography has been anticipated as refinements in this technique are introduced. We present the case of an unruptured, 11-mm pericallosal arterial aneurysm not visualized on high-resolution MR angiography. Although this case may be atypical, we caution against complete reliance on this test for exclusion of the presence of cerebral aneurysms.


2005 ◽  
Vol 103 (6) ◽  
pp. 1046-1051 ◽  
Author(s):  
Mohammad A. Jamous ◽  
Shinji Nagahiro ◽  
Keiko T. Kitazato ◽  
Junichiro Satomi ◽  
Koichi Satoh

Object. Estrogen has been shown to play a central role in vascular biology. Although it may exert beneficial vascular effects, its role in the pathogenesis of cerebral aneurysms remains to be determined. To elucidate the role of hormones further, the authors examined the effects of bilateral oophorectomy on the formation and progression of cerebral aneurysms in rats. Methods. Forty-five female, 7-week-old Sprague—Dawley rats were divided into three equal groups. Group I consisted of intact rats (controls). To induce cerebral aneurysms, the animals in Groups II and III were subjected to ligation of the right common carotid and bilateral posterior renal arteries. One month later, the rats in Group II underwent bilateral oophorectomy. Three months after the experiment began all animals were killed and cerebral vascular corrosion casts were prepared and screened for cerebral aneurysms by using a scanning electron microscope. Plasma was used to determine the level of estradiol and the gelatinase activity. Hypertension developed in all rats except those in the control group. The estradiol level was significantly lower in Group II than in the other groups (p < 0.01). The incidence of cerebral aneurysm formation in Group II (60%) was three times higher than that in Group III (20%), and the mean size of aneurysms in Group II (76 ± 27 µm, mean ± standard deviation) was larger than that in Group III (28 ± 4.6 µm) (p < 0.05). No aneurysm developed in control animals (Group I), and there was no significant difference in plasma gelatinase activity among the three groups. Conclusions. The cerebral aneurysm model was highly reproducible in rats. Bilateral oophorectomy increased the susceptibility of rats to aneurysm formation, indicating that hormones play a role in the pathogenesis of cerebral aneurysms.


2000 ◽  
Vol 93 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Toru Koyama ◽  
Kazuhiro Hongo ◽  
Yuichiro Tanaka ◽  
Shigeaki Kobayashi

✓ Despite recent advances in three-dimensional imaging based on a voxel-rendering method, these techniques do not simulate the morphological changes that occur during surgery. The authors' goal was to develop a computer-graphics model to simulate the manipulation that occurs during surgery when clipping a cerebral aneurysm.The authors developed an application program to interpolate the contours of models of an artery and an aneurysm clip. The center of displacement was determined inside the arterial model. The directions of displacement were changed to simulate saccular and broad-neck aneurysms, and the intensity of displacement was calculated by using a cosine-based formula. The morphological changes in a saccular aneurysm that may occur during clipping were calculated in x, y, and z coordinates by using sine- and cosine-based formulas. Clip movement was integrated with the aneurysm model, thus simulating the manipulation used during clipping of a cerebral aneurysm. Surgery performed to clip a basilar artery (BA) aneurysm via the transsylvian approach was simulated, in which displacement of the internal carotid artery and clipping of the BA aneurysm were necessary. The movements of an aneurysm clip and clip applicator were designed to represent those occurring when a surgeon actually manipulates a BA aneurysm.The authors have named this methodological tool “virtual clipping.” Use of this tool would assist the preoperative choice of clipping style and selection of the best clip.


1995 ◽  
Vol 82 (5) ◽  
pp. 898-899 ◽  
Author(s):  
Axel Perneczky ◽  
Georg Fries

✓ When operating on deep-seated cerebral aneurysms, the surgeon's visual control of clip application may be impaired by the clip holder unless adjacent structures are retracted. To improve visual control and reduce the necessity for retraction, the senior author (A.P.) developed a new concept: an aneurysm clip with an inverted-spring mechanism. The clip has two jaws that point away from the clip blades. The jaws of the clip holder articulate with the inner side of the clip jaws. By distending the jaws of the clip holder the blades of the clip are opened and vice versa. Thus the visual field increases while the clip application is proceeding. This instrumentation is useful, especially in cases of deep-seated aneurysms arising from the posterior circulation and in multiple aneurysms. In these latter cases even lesions located contralaterally could be reached with good visual control.


2005 ◽  
Vol 102 (3) ◽  
pp. 532-535 ◽  
Author(s):  
Mohammad A. Jamous ◽  
Shinji Nagahiro ◽  
Keiko T. Kitazato ◽  
Koichi Satoh ◽  
Junichiro Satomi

Object. The formation of cerebral aneurysms involves complex processes and little is known about the mechanisms by which they originate, grow, and rupture. The purpose of this study was to identify early ultrastructural morphological changes that lead to the formation of experimental cerebral aneurysms. Methods. Twenty male Sprague—Dawley rats were subjected to cerebral aneurysm induction (renal hypertension and right common carotid artery ligation); 10 intact rats served as the control group. The animals were killed after 2 months, and a vascular corrosion cast of their cerebral arteries was prepared and screened for aneurysm development by using a scanning electron microscope. Sequential morphological changes observed at the cerebral artery bifurcation in response to hemodynamic shear stress included endothelial changes, intimal pad elevation, and saccular dilation. Endothelial cell changes were the first observed morphological changes; they were followed by various degrees of artery wall dilation. No aneurysmal changes developed in any of the control rats. Of the 20 surgically treated rats, 11 displayed aneurysmal changes. In five of these animals only changes in the endothelial cell imprints could be identified. In the other six rats morphological changes in endothelial cells were associated with different stages of aneurysmal dilation. Conclusions. This is the first study to demonstrate in vivo early morphological changes that lead to the formation of cerebral aneurysms. The morphological findings indicate the principal role of endothelial cells in the pathogenesis of cerebral aneurysms and suggest that hemodynamic shear stress and blood flow patterns may precipitate these early changes.


1972 ◽  
Vol 37 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Masahiro Mizukami ◽  
Takashi Tomita ◽  
Toru Mine ◽  
Hiroshi Mihara

✓ In a series of 1107 patients with cerebrovascular disease studied by four-vessel angiography, the authors have found 10 cases of a bypass anomaly of the vertebral artery. Six of the cases also had cerebral aneurysms, and two cerebral arteriovenous malformations. The authors discuss the possible origins for this relationship.


1991 ◽  
Vol 74 (1) ◽  
pp. 133-135 ◽  
Author(s):  
Kevin Gibbons ◽  
Leo N. Hopkins ◽  
Roberto C. Heros

✓ Two cases are presented in which clip occlusion of a third distal anterior cerebral artery segment occurred during treatment of anterior communicating artery aneurysms. Case histories, angiograms, operative descriptions, and postmortem findings are presented. The incidence of this anomalous vessel is reviewed. Preoperative and intraoperative vigilance in determining the presence of this anomaly prior to clip placement is emphasized.


1999 ◽  
Vol 90 (5) ◽  
pp. 865-867 ◽  
Author(s):  
Harry J. Cloft ◽  
Nasser Razack ◽  
David F. Kallmes

Object. The aim of this study was to determine the prevalence of cerebral saccular aneurysms in patients with persistent primitive trigeminal artery (PPTA). The prevalence of cerebral saccular aneurysms in patients with PPTA previously has been reported to be 14 to 32%, but this rate range is unreliable because it is based on collections of published case reports rather than a series of patients chosen in an unbiased manner.Methods. The authors retrospectively evaluated their own series of 34 patients with PPTA to determine the prevalence of cerebral aneurysms in this population. The prevalence of intracranial aneurysms in patients with PPTA was approximately 3% (95% confidence interval 0–9%).Conclusions. The prevalence of intracranial aneurysms in patients with PPTA is no greater than the prevalence of intracranial aneurysms in the general population.


1977 ◽  
Vol 47 (3) ◽  
pp. 463-465 ◽  
Author(s):  
Antti Servo ◽  
Matti Puranen

✓ An aneurysm of the left middle cerebral artery was treated by clipping with a Heifetz clip. The correct placement was confirmed angiographically immediately after the operation. At carotid angiography 1 year later the clip was found to have broken, and the aneurysm had increased in size.


1989 ◽  
Vol 71 (2) ◽  
pp. 175-179 ◽  
Author(s):  
David W. Newell ◽  
Peter D. LeRoux ◽  
Ralph G. Dacey ◽  
Gary K. Stimac ◽  
H. Richard Winn

✓ Computerized tomography (CT) infusion scanning can confirm the presence or absence of an aneurysm as a cause of spontaneous intracerebral hemorrhage. Eight patients who presented with spontaneous hemorrhage were examined using this technique. In five patients the CT scan showed an aneurysm which was later confirmed by angiography or surgery; angiography confirmed the absence of an aneurysm in the remaining three patients. This method is an easy effective way to detect whether an aneurysm is the cause of spontaneous intracerebral hemorrhage.


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