Late angiographic follow-up review of surgically treated aneurysms

De novo basilar tip aneurysm. Case report and literature review

The de novo aneurysms are the formation of new aneurysms in a location previously observed to be normal by a cerebral angiography or direct microsurgical exploration. In this report, we present a review of the theme and describe a case of a ruptured de novo basilar tip aneurysm in a patient previously treated with carotid occlusion for a giant intracavernous aneurysm and microsurgical clipping of contralateral posterior communicating artery aneurysm.

Feasibility of flat panel angiographic CT after intravenous contrast agent application in the postoperative evaluation of patients with clipped aneurysms

BACKGROUND AND PURPOSE

Important findings, such as aneurysm remnants or major arterial occlusion, can be detected on intra- or postoperative angiography after surgical clipping of intracranial aneurysms. The purpose of this study was to evaluate the feasibility of IV-ACT for the postoperative detection of residual aneurysms and parent vessel patency compared with IA-DSA, which was selected as the standard reference method.

MATERIALS AND METHODS

Twenty-two patients with 27 aneurysms treated by surgical clipping were examined by using both IA-DSA and IV-ACT. Both diagnostic procedures were performed on an FPD-equipped angiography system. Postprocessing of IV-ACT acquisitions was performed on a dedicated workstation producing multiplanar reformations and maximum intensity projections of the clip region and other intracranial arteries. Three interventional neuroradiologists independently evaluated both procedures.

RESULTS

A residual aneurysm was delineated in 10 cases with IA-DSA. Sufficient opacification of the intracranial vessels was assigned in 26 IV-ACT cases. Due to metal artifacts, IV-ACT images were tagged as "not diagnostic" on 8 occasions. In the other 19 aneurysms, a residual aneurysm was delineated in 6 cases-all 6 being true-positive compared with IA-DSA-and was excluded in the remaining 13 cases-all true-negative. Even small aneurysm remnants with a diameter of 1.5 mm were detected with IV-ACT.

CONCLUSIONS

Currently IV-ACT cannot be recommended as a routine tool for postoperative evaluation of clipped aneurysms due to metal artifacts in 30% of the examinations. These artifacts appear with multiple normal-sized or large clips. In patients with single or multiple small clips, IV-ACT can reliably show aneurysm remnants.

Middle cerebral artery aneurysms in children: case series and review

OBJECT

Pediatric intracranial aneurysms are rare lesions that differ from their adult counterparts. Aneurysms involving the middle cerebral artery (MCA) are particularly challenging to treat in children, as they are often fusiform and cannot undergo direct clipping alone. The authors recently treated a patient with a heavily calcified, dysplastic, left-sided MCA aneurysm. The present study was performed to evaluate the authors' previous operative and follow-up experience with these difficult lesions.

METHODS

The authors performed a review of a prospectively maintained database of all aneurysms treated at Methodist Hospital in Indianapolis, Indiana, from January 1990 through November 2010. Relevant operative notes, clinical charts, and radiological reports were reviewed for all patients 18 years of age or younger.

RESULTS

A total of 2949 patients with aneurysms were treated over the study period, including 28 children (0.95%). Seven children harbored MCA aneurysms. Five of these 7 aneurysms (71.4%) were fusiform. Two patients were treated with direct clipping, 2 underwent parent vessel occlusion without bypass, and 3 underwent aneurysm trapping with extracranial-intracranial vessel bypass. Long-term follow-up data were available in 6 cases. All 6 patients had a 1-year follow-up Glasgow Outcome Scale score of 5. Long-term radiological follow-up was available in 4 patients. One patient required a reoperation for a recurrent aneurysm 4 years after the initial surgery.

CONCLUSIONS

Middle cerebral artery aneurysms in children are often fusiform, giant, and incorporate the origins of proximal artery branches. Direct clipping may not be possible; trapping of the lesion may be required. Children seem to tolerate surgical trapping with or without bypass extremely well. Aggressive therapy of these rare lesions in children is warranted, as even patients presenting with a poor clinical grade may have excellent outcomes. Long-term surveillance imaging is necessary because of the risk of aneurysm recurrence.

Extended follow-up of unruptured intracranial aneurysms detected by presymptomatic screening in patients with autosomal dominant polycystic kidney disease

BACKGROUND AND OBJECTIVES

Autosomal dominant polycystic kidney disease (ADPKD) patients have an increased risk for intracranial aneurysms (IAs). The importance of screening for unruptured IAs (UIAs) depends on their risks for growth and rupture.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

ADPKD patients with UIAs found by presymptomatic screening with magnetic resonance angiography (MRA) during 1989 to 2009 were followed initially at 6 months and annually, and less frequently after demonstration of stability.

RESULTS

Forty-five saccular aneurysms were detected in 38 patients from 36 families. Most were small (median diameter 3.5 mm) and in the anterior circulation (84%). Median age at diagnosis was 49 years. During cumulative imaging follow-up of 243 years, one de novo UIA was detected and increased in size from 2 to 4.4 mm over 144 months and two UIAs grew from 4.5 to 5.9 mm and 4.7 to 6.2 mm after 69 and 184 months, respectively. Seven patients did not have imaging follow-up. No change was detected in the remaining 28 patients. During cumulative clinical follow-up of 316 years, no aneurysm ruptured. Five patients died from unrelated causes and two were lost to follow-up after 8 and 120 months. Three patients underwent surgical clipping.

CONCLUSIONS

Most UIAs detected by presymptomatic screening in ADPKD patients are small and in the anterior circulation. Growth and rupture risks are not higher than those of UIAs in the general population. These data support very selective screening for UIAs in ADPKD patients, and widespread screening is not indicated.

De Novo Aneurysm: Case Reports and Literature Review

BACKGROUND AND IMPORTANCE:

Formation of cerebral de novo aneurysms (CDNAs) is rare, and the pathogenesis remains obscure. We analyzed factors involved in formation of CDNAs and suggest guidelines for follow-up of patients.

CLINICAL PRESENTATION:

We retrospectively reviewed intracranial aneurysms at our institute and published reports from 1964 to 2008. Eleven patients were found with CDNAs, and 138 patients were collected from the published literature. We assessed the clinical characteristics, such as sex, size, and site of CDNA, past history, and time to occurrence of CDNAs. Of 11 patients, 10 were female and 1 was male; the mean age of the first onset was 53 years (range, 25-69 years). The mean time between first aneurysms and CDNAs was 10.6 years (range, 3-29 years). The most common site of occurrence was anterior circulation. One patient experienced contralateral occurrence, and 2 patients changed from anterior to posterior circulation CDNAs. Six (54.5%) patients had a history of arterial hypertension. Results from analysis of the whole series from the literature revealed that the risk of rupture increased with a previous history of hemorrhage. Contralateral occurrence of CDNAs was related to previous location, and multiplicity, whereas the occurrence of anterior to posterior changes of CDNAs and shorter interval only correlated with an older age group.

CONCLUSION:

Although the formation of CDNAs is rare, several factors may contribute to its occurrence. Female patients with a history of arterial hypertension were at a higher risk for CDNA occurrence. We recommend follow-up imaging studies within 10 years after the initial aneurysms; therefore, at least 50% of CDNAs can be found before rupture.

Role of calcification in the outcomes of treated, unruptured, intracerebral aneurysms

PURPOSE

This study examined clinical and aneurysm characteristics in patients with unruptured aneurysms, treated with either coiling or clipping at a single institution, with the primary outcome-Glasgow Outcome Score (GOS)-measured at 6 months after treatment.

METHODS

Data was obtained by a retrospective review of a prospective registry of consecutive cases of unruptured intracranial aneurysms treated at a single institution from 2002 to mid 2007. Demographic data, number, location, and size of aneurysms, calcification, mode of treatment, ASA score, presence of a stroke on post-op imaging, and GOS were recorded. Medical 9.4 for PC was utilized for statistical analysis.

RESULTS

There were 225 procedures performed in 208 patients to treat 252 aneurysms. The mean age was 54.6 years, 74.5% were female, the mean ASA score was 2.45, and 72.2% were smokers. Mean aneurysm size was 8.6 mm. A total of 157 (70%) craniotomies and 68 (30%) coiling procedures were performed. Coiling was utilized more frequently in the posterior circulation [18/32 (56%) posterior circulation, 50/193 (29.9%) anterior circulation, p < 0.001 Chi-square]. Length of hospital stay averaged 5.3 days [6.2 vs. 3.2 clip/coil, p < 0.001, Mann-Whitney]. Overall favorable outcome of GOS 4-5 measured at 6 months post-procedure was 93.3% [145/157 (92.3%) clip, 66/68 (97%) coil, p = 0.3 Chi-square], with a single mortality in the coil group. There was radiographic evidence of a post-procedure stroke on CT in 31 (13.8%) [28/157 (17.8%) clip, 3/68 (4.4%) coil, p < 0.001, Chi-square], but only 11(35%) were symptomatic. All long-term morbidity was attributable to stroke except for one case of late hydrocephalus. Utilizing a logistic regression multivariate analysis (forward), none of the examined factors (age, ASA score, sex, surgeon, posterior circulation, number of aneurysms treated at one sitting, size of aneurysm, smoking status, or type of therapy) related to outcome except calcified aneurysm [20/25 (80%) calcified, 191/200 (95.5%) non-calcified, p < 0.01 Chi-square] with an OR = 7.8 (2.2-28.4, 95% C.I.). Although a univariate analysis of aneurysm size versus outcome achieves statistical significance [p = 0.05, logistic regression (forced)], when the calcified cases are removed from consideration, it does not [p = 0.55, OR = .95, (.82-1.1), 95% C.I.]. Excluding patients with calcified aneurysms resulted in the following calculation of favorable outcome: 94.2% (130/138) clip and 98.4% (61/62) coil [p = 0.33, Chi-square].

CONCLUSIONS

In this study, the presence of calcification in an aneurysm was the sole marker of adverse outcome. Larger aneurysms tended to be more likely to be calcified. Size by itself did not have an adverse affect on outcome. Clipping or clip reconstruction of calcified aneurysms is a significant source of morbidity in the treatment of unruptured aneurysms (Odds ratio 7.8).

Treatment Outcome of Aneurysmal Subarachnoid Hemorrhage in Patients Aged 70 Years and Older

BACKGROUND:

The incidence of subarachnoid hemorrhage is increasing, especially in the elderly as life expectancy increases. Aggressive treatment of aneurysms in the elderly is usually avoided because of a presumed poor prognosis.

OBJECTIVE:

The aim of this study was to assess the outcome of treatment in patients older than 70 years old.

METHODS:

We performed a retrospective chart review of 150 patients aged 70 years and older who were treated at Jefferson Hospital from 2004 to 2009. Data including World Federation of Neurological Surgeons grade and Hunt and Hess classification, specific management components, and treatment outcome on discharge were analyzed.

RESULTS:

One hundred ten patients had aneurysms coiled, 9 patients had aneurysms clipped, 11 patients had aneurysms that were not treated, and 20 patients had no visible aneurysms. Overall, increased World Federation of Neurological Surgeons grades correlated strongly with poor clinical outcome. Statistical tests indicate that patients who died (mean, 78.8, n = 35) or who went into rehabilitation (mean, 76.5, n = 81) were significantly older than patients who were discharged home (mean, 73.1, n = 20). However, day of presentation after initial symptom(s) of subarachnoid hemorrhage and placement of ventriculoperitoneal shunt also influenced clinical outcome. Patients who had a ventriculoperitoneal shunt were more likely to go into rehabilitation than patients who did not, and patients without a ventriculoperitoneal shunt were more likely to die.

CONCLUSION:

Older age should not preclude a patient from aneurysm treatment. Factors such as low Hunt and Hess or World Federation of Neurological Surgeons grades, earlier presentation to the hospital after initial symptoms, early shunting, prompt interventions, and tailored postoperative management can result in favorable clinical outcomes.

Single-center experience of surgical and endovascular treatment of ruptured intracranial aneurysms

BACKGROUND AND PURPOSE

ISAT provided valuable data on patient outcome after endovascular coiling and surgical clipping of ruptured aneurysms. The purpose of this study was to retrospectively review the ≥1-year outcome (in terms of survival, independence, and rebleeding) of patients who were treated in a routine clinical setting.

MATERIALS AND METHODS

Records of patients presenting with an SAH from a ruptured aneurysm between 2000 and 2008 were reviewed. The 403 patients who met the inclusion criteria harbored 443 treated aneurysms; 173 were managed surgically and 230 by endovascular means. Mean clinical follow-up was 33.9 months (range, 12-106 months).

RESULTS

The pretreatment clinical condition according to the HH was significantly better in the surgically treated patients (P = .018). Death occurred in 11.6% after surgery and in 17.4% after endovascular treatment (P = .104). Of the surviving patients in the surgical and endovascular groups, 80.3% and 87.2%, respectively, were able to live independently with grades 0-2 on the mRS (P = .084). Complete aneurysm occlusion was achieved significantly more often after surgical treatment (P < .001). Rebleeding occurred in 3.1% and 2.3% of the patients after surgical treatment and endovascular coiling, respectively. The occurrence of a residual aneurysm at the end of a coiling procedure was significantly related to the frequency of rebleeding (P = .007).

CONCLUSIONS

The management of patients with intracranial aneurysms in a routine clinical setting shows good and comparable rates of mortality and independence. Coiling results in lower rates of complete aneurysm occlusion. Postcoiling angiography showing a residual aneurysm is a good predictor of the risk of rebleeding.

Role of intraoperative microvascular Doppler in the microsurgical management of intracranial aneurysms

BACKGROUND

The outcome of surgical treatment of intracranial aneurysms may be influenced by incomplete exclusion of the aneurysm or stenosis of the parent vessels. The goal of this study was to evaluate the usefulness and reliability of intraoperative microvascular Doppler (IMD) in guiding optimal clip placement in aneurysm surgery.

METHODS

We conducted a retrospective analysis of 79 patients, with a total of 85 intracranial aneurysms, operated between January 2004 and April 2009, who were evaluated with IMD using a 20-MHz probe before and after clip application. IMD was used to examine the aneurysmal sac and adjacent vessels.

RESULTS

The findings of IMD helped in adjusting the clip placement. In 9 (10.6%) of the 85 aneurysms, IMD revealed a persistent blood flow through the aneurysmal sac after clip application and the clip was repositioned. IMD showed relevant stenosis of adjacent vessels induced by the clip positioning in 10 of 79 (12.7%) cases. In six cases (7.6%), a blood flow reduction in the artery feeding the aneurysm was evident after clipping; in the other four cases (5.1%), the clip produced a severe blood flow reduction in other adjacent vessels. In addition, in two of these cases, an initial stenosis induced by clip positioning that had escaped detection by visual inspection through the operating microscope was identified by IMD. There were no complications related to the use of IMD.

CONCLUSIONS

IMD is a safe, feasible, and very reliable technique and should be used routinely in intracranial aneurysm surgery.

Surgical indications and techniques for failed coiled aneurysms

For two decades, endovascular coiling has revolutionized the treatment of intracranial aneurysms. However, as with all techniques, it has limitations and endovascular radiologists and neurosurgeons are regularly confronted by what we call "failed" coiled aneurysms. Failed coiled aneurysms can occur in different situations: a) presence of a significant remnant at the end of an endovascular procedure; b) recanalization of an initially satisfactory occlusion; and c) coil extrusion deemed too thrombogenic or threatening the blood flow in the parent vessel. We and other teams around the world have developed strategies to manage these difficult cases. Here, we compare our own experience with other reports in the literature.

Clinical presentation and outcomes of coil embolization of remnant or recurred intracranial aneurysm after clipping

OBJECTIVE

To evaluate clinical presentation, safety, techniques, clinical and angiographic outcomes, and prognostic factors of coiling for remnant/recurred aneurysm after clipping.

METHODS

Twenty-four consecutive patients (11 men and 13 women; mean age, 52 years) with 24 recurred/remnant aneurysms after clipping underwent coil embolization between September 2000 and December 2008. Clinical presentations of remnant/recurred aneurysms, safety, techniques, clinical and angiographic outcomes, and prognostic factors of coil embolization were retrospectively evaluated.

RESULTS

Twenty-two aneurysms initially presented with subarachnoid hemorrhage and the other two, with mass effect. Eight aneurysms presented with rebleeding and 16 aneurysms were found on follow-up CT angiogram (n = 12) or catheter angiogram (n = 4). The interval between clipping and coiling ranged from 8 days to 114 months (mean, 31 months). Twelve were treated by using single-catheter, 6 by stent-assisted, 4 by multicatheter, 1 by both balloon- and catheter-assisted, and 1 by balloon-in-stent technique. Immediate postembolization angiogram revealed complete obliteration (n = 19) or residual neck (n = 5). Procedure-related permanent morbidity and mortality rates were 4.2% (1 of 24) and 0%, respectively. There was no rebleeding during clinical follow-up for 3 to 82 months (mean, 24 months). Presentation with rupture after clipping was the only significant predictor of poor outcome (P < .05).

CONCLUSION

Coiling seems to be a safe and effective retreatment option for remnant/ recurred aneurysm after clipping. Presentation with rupture after clipping is the only predictor of poor outcome. For routine/regular follow-up after clipping, CT angiography may be the imaging modality advisable for detection of remnant/recurred aneurysm.

Microsurgical treatment of ruptured intracranial aneurysm: a 120-case analysis

OBJECTIVE

to investigate the influence of pre-operative conditions and microsurgical skill on the post-operative outcomes of intracranial aneurysms by retrospective analysis of 120 cases with microsurgical treatment.

METHODS

120 patients with 134 intracranial aneurysms received microsurgical treatment via pterional approach or improved pterional approach.

RESULTS

of 134 aneurysms, 122 were clipped, one was coated, three were isolated and there was parent artery deligation in one case. 111 Patients were cured, seven cases gave up therapy post-operation, and two died. According to GOS standard, the outcome in the discharge stage was good in 94 cases, mild disability in 12 cases, moderate disability in three cases and severe disability in two cases. Long-term follow-up was performed in all patients, of whom 95 recovered well, mild disability in 12 cases, moderate disability in two cases and severe disability in one case.

CONCLUSION

surgical clipping was the most effective method to treat intracranial aneurysm. Optimal chance and microsurgical technique, as well as microanatomical knowledge, are keys for successful treatment.

Histomorphology of thrombus organization, neointima formation, and foreign body response in retrieved human aneurysms treated with hydrocoil devices

Biological processes, such as thrombus organization, endothelialization, and foreign body response, that occur following embolization of intracranial aneurysms are poorly understood. We examined 13 human aneurysms (retrieved at autopsy 1-74 days postembolization) treated with hybrid hydrogel-platinum coil devices and platinum coils. The specimens were embedded in methyl methacrylate and ground sections were surface stained. Using light microscopy, thrombus organization in the sac, endothelialization of the neck, and foreign body response to the embolic devices were determined. The area percentages of the sac occupied by embolic devices and unorganized thrombus were quantified using image analysis. Thrombus organization increased over time, but was incomplete up to 74 days post-treatment. Neointima formation had started at 5 days upon dense fibrin depositions and progressed to form a new vessel wall at 74 days. The foreign body response to the hydrogel was characterized by mononuclear macrophages, while platinum coils were surrounded by multinuclear foreign body giant cells. Histometric aneurysm occlusion ranged from 89 to 100% and embolic devices occupied 31-64% of the aneurysm sac. These findings showed that the hydrogel-based devices occupied a large percentage of the aneurysm sac, provided a framework for thrombus organization to occur, and elicited less severe foreign body response than platinum coils.

Near-infrared indocyanine green videoangiography versus microvascular Doppler sonography in aneurysm surgery

INTRODUCTION

The quality of surgical treatment of intracranial aneurysms is determined by complete aneurysm occlusion and restoration of flow in the parent, branching and perforating vessels. In postoperative digital subtraction angiography (DSA), unexpected aneurysm residuals and vessel occlusions are frequently detected. Here, the value of two nearly noninvasive and cost-effective techniques for intraoperative flow evaluation (near-infrared indocyanine green video angiography (ICG-VA) and microvascular Doppler sonography (mDs)) is investigated in a prospective study.

PATIENTS AND METHODS

Over a period of 10 months, the authors surgically clipped 50 aneurysms under intraoperative pre- and post-clipping evaluation of flow in the parent, branching and perforating vessels and the aneurysm sack by the two techniques. Intraoperative applicability of each technique was compared to each other and to postoperative digital subtraction angiography as standard evaluation technique.

RESULTS

Forty-five aneurysms were totally occluded without vessel compromise (90%). Intraoperatively, ICG-VA was considered useful in 43 cases (86%) and mDs in 44 cases (88%), respectively. Both techniques could compensate each other's weak points to a certain degree; but two branch occlusions (4%) and three neck remnants (6%) were revealed by postoperative DSA.

CONCLUSION

Both techniques have specific drawbacks that could be compensated by each other, to a certain extent. Intraoperatively, ICG-VA and mDs should not be considered competitive, but complementary. This study implicates that the combination of both applications on a routine basis assures the quality of aneurysm surgery by nearly noninvasive and cost-effective techniques. However, DSA remains the gold standard for evaluation of aneurysm occlusion.

Microsurgical Treatment of Pediatric Intracranial Aneurysms

BACKGROUND

Pediatric aneurysms are rare and complex to treat. Long-term angiographic and clinical data after microsurgical or endovascular therapies are lacking.

OBJECTIVE

To study the clinical and radiographic outcomes in aneurysms in pediatric patients treated with microsurgery.

METHODS

Between 1989 and 2005, 48 patients ≤ 18 years of age (28 boys, 20 girls; mean age, 12.3 years) were treated for intracranial aneurysms. Patient charts were reviewed retrospectively for age, presentation, type and location of aneurysm(s), surgical approach, complications, and clinical and angiographic outcomes. Rates of aneurysm recurrence and de novo formation were calculated.

RESULTS

Seventy-two aneurysms were treated. Presentations included incidental aneurysm (35%), aneurysmal subarachnoid hemorrhage (17%), stroke (13%), and traumatic subarachnoid hemorrhage (10%). Location was anterior circulation in 76% and posterior circulation in 24%. Twenty-eight (39%) were fusiform/dissecting, and 16 (23%) were giant. Most aneurysms were clipped directly. A vascular bypass with parent-vessel occlusion was used to treat 13 aneurysms (18%). Hypothermic circulatory arrest was used to treat 10 aneurysms (14%), all involving the basilar artery. The perioperative morbidity rate was 25%. There were no deaths. The long-term morbidity rate was 14%, and the mortality rate was 3%. Clinical outcome was favorable in 92% and 94% at discharge and follow-up, respectively (mean, 59 months; median, 32 months). At angiographic follow-up (mean, 53 months; median, 32 months), the annual recurrence rate was 2.6%, and the annual rate of de novo formation or growth was 7.8%.

CONCLUSION

Pediatric aneurysms require complex microsurgical techniques to achieve favorable outcomes. They leave higher rates of recurrence and de novo formation or growth than their adult counterparts, which mandates lifelong follow-up.

Surgical and endovascular treatments for intracranial aneurysms

The goals of microsurgical and endovascular treatment of intracranial aneurysms are to prevent subarachnoid hemorrhage and/or eliminate mass effect symptoms. Debate has raged regarding which aneurysms to treat and with which technique or combination of techniques. It is our impression that studies that have assessed aneurysm natural history and treatment options are compromised by the inherent limitations of clinical trials, with many natural history studies likely underestimating rupture risk over long-term follow-up. Endovascular therapy and open neurosurgery should both be used strategically, and our current interest is in integrating these techniques in a fashion extending beyond the simplistic clip-versus-coil debate.

Inappropriate application of Yaşargil aneurysm clips: a new observation and technical remark

OBJECTIVE

Recurrences after complete surgical clipping of an aneurysm base are rare. We describe a potential reason for such recurrences: the inappropriate application of a popular aneurysm clip.

CLINICAL PRESENTATION

We present 3 cases in which intraoperative indocyanine green video angiography after clipping clearly demonstrates filling of the aneurysm.

INTERVENTION

During surgery, the necks of the aneurysms were clipped with Yaşargil aneurysm clips (Aesculap AG & Co., Tuttlingen, Germany) without any problems; however, indocyanine green video angiography after clipping showed filling of the aneurysms through the point located at the junction of the blade and spring portions of the clips. In the first patient, the aneurysm sac was further coagulated, and a second, smaller clip was applied to completely occlude the untreated part. In the second patient, the clip was replaced with a different clip that had longer blades. In the third patient, 2 additional clips were applied, and the aneurysm sac was also coagulated. The postoperative computed tomographic angiographic examinations showed total occlusion of the aneurysms and patency of the parent arteries. All patients achieved full recovery after the operations.

CONCLUSION

We present here, for the first time, evidence that the small orifice located at the junction of the blade and spring portions of Yaşargil aneurysm clips can lead to failure of initial surgery and/or recurrence. This can be avoided by using clips with slightly longer blades to keep the orifice away from the aneurysm or by applying a second clip to occlude the untreated part.

Usefulness of multislice computerized tomographic angiography in the postoperative evaluation of patients with clipped aneurysms

BACKGROUND

The aim of our study was to evaluate the diagnostic efficacy of multislice computed tomographic angiography (MSCTA) regarding exclusion quality after aneurysm clipping.

METHODS

Sixty patients (74 aneurysms) underwent microsurgical exclusion using titanium clips. The presence of aneurysm remnants on MSCTA was compared by a neuroradiologist to 2D digital subtraction angiography (DSA), which was considered as a reference examination. The contribution of 3D DSA was assessed in a subpopulation of 29 patients (35 aneurysms).

RESULTS

With 2D DSA, six aneurysm remnants (8%) were diagnosed, and only five (7%) by MSCTA. The specificity and sensitivity were 98.5 and 83%, respectively. MSCTA failed to demonstrate one large remnant (>2 mm) because of clip artifacts (six clips). With 3D DSA six supplementary remnants were diagnosed. Two were large remnants blinded by vessel overlaps and clip artifacts. Four were small "dog-eared" remnants (< or =2 mm). No additional treatment was required for small remnants.

CONCLUSION

In the postoperative period, MSCTA was considered a useful tool to evaluate the large remnants as well as a non-invasive ulterior examination for suspected bifurcation. Nevertheless, 3D DSA is still required for an accurate evaluation of aneurysms treated by more than three clips.

Three-dimensional digital subtraction angiographic evaluation of aneurysm remnants after clip placement

OBJECTIVE

The aneurysm remnants rate was evaluated via three-dimensional digital subtraction angiography (3D-DSA) in the postoperative evaluation of clipped aneurysms.

METHODS

Data on surgically clipped aneurysms of anterior circulation obtained via postoperative 3D-DSA from February 2007 to March 2009 were gathered. The results of the postoperative 3D-DSA and of two-dimensional digital subtraction angiography (2D-DSA) for the detection of aneurysm remnants were compared, and an investigation was performed as to why 2D-DSA had missed some aneurysm remnants that were detected in the 3D-DSA. Various surgical factors that revealed aneurysm remnants in the 3D-DSA were also evaluated.

RESULTS

A total of 39 neck remnants of 202 clipped aneurysms (19.3%) were confirmed in 3D-DSA, and these were classified according to Sindou's classification of aneurysm remnants. Patients with only a neck remnant found in the 3D-DSA represented 17.3% (35/202 aneurysms) of the whole series, and those with a residuum of neck plus sac found in the 3D-DSA represented 1.9% (4/202 aneurysms). The causes of aneurysm remnants were no full visualization (14/39, 35.9%), parent and perforator artery protection (10/39, 25.6%), clip design problems (8/39, 20.5%), and broad-necked aneurysm (7/39, 17.9%).

CONCLUSION

Patients with </= 2 mm aneurysm remnants showed an increased risk of undetectable aneurysm remnants in the 2D-DSA. The most frequent location of the missed aneurysm in 2D-DSA was the anterior communicating artery. 3D-DSA showed more aneurysm remnants than what is indicated in the existing literature, the 2D-DSA.

[Treatment of grade 0 intracranial aneurysms: Retrospective study of 79 cases]

AIM

Without precise international recommendations, despite the advances of the ISUAA study, the superiority of microsurgery or endovascular treatment for unruptured intracranial aneurysm (UIA) over the natural history of this disease has not been proved. In this context, the authors evaluate their experience with the aim of assessing the results and risks of the different therapeutics and comparing them with the natural risk of this disease.

MATERIAL AND METHOD

From January 1993 to July 2000, 79 patients harboring 110 UIAs were treated. These patients were divided retrospectively into two groups. Group A included 45 operated patients. Group B included 37 patients treated with endovascular coiling. The therapeutic choice was not randomized and was approved by a multidisciplinary neurovascular staff.

RESULTS

The two populations were homogeneous in terms of age and sex. In group A, 12 patients presented early complications (26.6 %), with one death. In group B, 15.6 % of the patients presented an ischemic complication. After 1 year of follow-up, morbidity was 11.4 % in group A and 4.8 % for group B. Angiography found a partial recanalization in 12.5 % of the operated patients and in 33 % of the patients treated with endovascular coiling.

DISCUSSION

Many factors are involved in the therapeutic decision: UIA location and size and individual risks. Progress in both surgery and interventional neuroradiology has led to good results conforming with the data reported in the literature but does not demonstrate the superiority of one technique over another.

Application of microscope integrated indocyanine green video-angiography during microneurosurgical treatment of intracranial aneurysms: a review

Indocyanine Green Video Angiography (ICG-VA) is recently introduced to the practice of cerebrovascular neurosurgery. This technique is safe and noninvasive and provides reliable real-time information on the patency of blood vessels of any size, as well as residual filling of aneurysms. In this article, a review of the literature and our experience with ICG-VA during microneurosurgery of intracranial aneurysms is presented.

Results of surgical management for posterior cerebral artery aneurysms: 7-year experience in the endovascular era

PURPOSE

Unlike most posterior circulation aneurysms, posterior cerebral artery (PCA) aneurysms can be surgically approached, we believe, without significant technical difficulty or procedural morbidity. We report our recent experience to assess procedural complications and clinical outcomes for PCA aneurysms.

METHODS

In our retrospective review of 15 consecutive patients with PCA aneurysms, six patients underwent surgical treatment, six patients had endovascular coiling, (three patients from the endovascular group also underwent surgical revascularization), and three patients were treated conservatively (medical or observation) (2001-2007). Clinical records were reviewed for: patient demographics; clinical presentation; aneurysm location, size, and morphology; treatment; procedural complications; outcome (clinical and angiographic).

RESULTS

Complete aneurysm obliteration with parent vessel or bypass patency was demonstrated by intraoperative angiography in all patients. One patient died and two patients suffered procedure-related permanent neurologic injury. Considering both surgical end endovascular treatment modalities, mortality was 8.3% and permanent morbidity was 16.6%. At mean clinical follow-up of 2-96 months (15.8 +/- 10.5 months), nine of ten patients had a Glasgow Outcome Score of 4 or 5. In patients who underwent bypass procedures, computed tomographic (CT) angiography or cerebral angiography demonstrated a patent functional bypass before the PCA occlusion.

CONCLUSIONS

Our findings for these 15 patients suggest the value of a multimodality of treatments for PCA aneurysms. Revascularization of the PCA can be performed with favorable technical results and clinical outcomes when the patency of the PCA cannot be preserved.

Recurrent subarachnoid hemorrhage after complete obliteration of intracranial aneurysm

The authors report a case of recurrent subarachnoid hemorrhage (SAH) after complete occlusion of an intracranial aneurysm. It is known that regrowth of an aneurysm after the complete clipping is a rare event. For detection of recurrence, however, it may be necessary to follow up with the patient regularly after the initial operation for intracranial aneurysms, because re-rupture of an aneurysm can cause a fatal result, and the cumulative risk of a recurrent SAH is thought to be not low over time.

The combined approach to intracranial aneurysm treatment

BACKGROUND

A consecutive series of patients with intracranial aneurysms in the practice of one neurovascular surgeon was retrospectively reviewed to illustrate that one physician can become proficient in microneurosurgery as well as endovascular surgery and achieve favorable outcomes in both disciplines. This supports one model of training for cerebrovascular surgeons that includes the complimentary practice of open microneurovascular surgery with endovascular surgery.

METHODS

The senior author (HAR) treated 351 patients with 413 aneurysms between July 2001 and March 2007. Of these, 172 patients (216 aneurysms) were treated with open microneurosurgical techniques and 179 patients (197 aneurysms) were treated using endovascular techniques.

RESULTS

Complete obliteration was attained in 94.3% of clipped aneurysms, and 61.9% and 65.9% of coiled aneurysms immediately and after at least 6 months of follow-up, respectively. At latest evaluation, 93% of endovascular patients and 90% of microneurosurgical patients had good clinical outcomes (GOS, 4 or 5; mean follow-up, 23 months; combines ruptured and unruptured cohorts). Procedure-related mortality included 1 surgical patient and 2 endovascular patients.

CONCLUSIONS

Because the fields of microvascular and endovascular surgeries are both technically complex, there has been concern that hybrid cerebrovascular surgeons cannot perform each technique with the skill necessary to achieve good outcomes. When compared to clipping and coiling reviews in the neurosurgical literature, we illustrate that one hybrid neurovascular surgeon is capable of attaining great facility in both techniques and that this type of physician will represent one practice model of cerebrovascular specialist in the future. This has potential implications for the training of hybrid cerebrovascular surgeons.

Concept of ideal closure line for clipping of middle cerebral artery aneurysms--technical note

The concept of optimum closure line was applied to a series of 51 consecutive middle cerebral artery aneurysms (14 ruptured, 37 unruptured) in 41 patients, 16 men and 25 women aged 29-79 years (mean 59.1 years). Visual inspection through the operating microscope revealed 3 types of aneurysm based on the origin of the aneurysm: bifurcation type (n = 39), trunk type (n = 9), and combined type (n = 3). Clipping along the optimum closure line should restore the vascular structure to the original configuration. Combination clip techniques were useful to form a curved closure line. This technique requires adequate operative fields with dissection of the aneurysm and related arteries from the neighboring structures as far as possible. The closure line concept is helpful to decide how to apply clips for particular aneurysms to avoid risks of ischemic complication and future recurrence. Combination clip techniques are often necessary to match a curved closure line.

Cost-effectiveness of clipping vs coiling of intracranial aneurysms after subarachnoid hemorrhage in a developing country--a prospective study

BACKGROUND

Endovascular coil treatment is being used increasingly as an alternative to clipping for some ruptured intracranial aneurysms. The relative benefits of these 2 approaches have yet to be fully established. The aim of this study was to compare the clinical outcome, resource consumption, and cost-effectiveness of endovascular treatment vs surgical clipping in a developing country.

METHODS

The study population consisted of 55 patients with aneurysmal subarachnoid hemorrhage (SAH) identified prospectively from January 2004 to June 2007. Of the 55 patients with ruptured intracranial aneurysms, 31 underwent surgical clipping, whereas 24 were treated via interventional coils. Clinical outcome at 6 months, using the modified Rankin Scale, and cost of treatment related to all aspects of the inpatient stay were evaluated in both groups.

RESULTS

The average age of the patients in the endovascular group was 38 years, whereas in the surgical group, it was 45 years. Most patients (43) were found to be in grades (1 and 2). Of these patients, 18 received coils and 25 were clipped. The remaining 12 patients were of poor grades (3 and 4), of which 6 had coiling and 6 underwent clipping. Most the patients (46/55) had anterior circulation aneurysms, and the rest of the patients (9/55) had posterior circulation aneurysms. The clinical outcome was similar in comparison (good in 81% for clipping and 83% for coiling). The average total cost for patients undergoing endovascular treatment of the aneurysms was $5080, whereas the average total cost of surgical clipping was $3127.

CONCLUSION

Patients with aneurysmal SAH whom we judged to require coiling had higher charges than patients who could be treated by clipping. The benefits of apparent decrease in length of stay in the endovascular group were offset by higher procedure price and cost of consumables. There was no significant difference in clinical outcome at 6 months. We have proposed a risk scoring system to give guidelines regarding the choice of treatment considering size of aneurysm and resource allocation.

Angiography postclipping and coiling of cerebral aneurysms

Postclipping cerebral angiography is generally not practised in the UK. The International Subarachnoid Trial (ISAT) data show that coiling compared favourably with clipping in the early posttreatment phase. We present a 4-year, single unit experience comparing cerebral angiography at 6 months postclipping and postcoiling, defining the proportion of aneurysms in either group, which were incompletely excluded from the cerebral circulation after treatment. There were 4 'dog-ear' remnants (4.6%) in the clipping group of 86 aneurysms, one of which required further surgery. Thirty-one out of 82 (37.8%) coiled aneurysms that underwent check angiography were inadequately excluded from the cerebral circulation at 6 months. Of these, to date, four patients have undergone re-coiling. Although the immediate complications of coiling may be less than those of clipping (ISAT), it seems that the degree and permanence of exclusion of an aneurysm from the cerebral circulation may be more secure with surgery. In summary, the rates of incomplete aneurysmal exclusion from the cerebral circulation, the requirement for reintervention and the requirement for continuing surveillance were all higher in the coiled population than in the clipped population.

Techniques of reoperation for a giant regrown anterior communicating artery aneurysm harboring long-implanted clips and compacted coil mesh

A 57-year-old woman presented with a progressive deterioration of vision. She had previously undergone clipping for a ruptured small anterior communicating artery (Acom) aneurysm 7 years prior to admission and additional coiling for recurrence 2 years prior to admission. Angiography showed regrown out-pouching of the sac, which measured 27 x 18 mm. A decision was made to perform surgical treatment to alleviate the mass effect of the aneurysm. Unique techniques for revision of the scarred surgical corridor, removal of old clips, resection of the coiled mass, thrombectomy, and intra-aneurysmal endarterectomy were required to allow placement of the final clips. The patient recovered uneventfully, and her vision was satisfactorily restored.

EVALUATION OF ONYX HD-500 EMBOLIC SYSTEM IN THE TREATMENT OF 84 WIDE-NECK INTRACRANIAL ANEURYSMS

OBJECTIVE

We report our results using Onyx HD-500 (Micro Therapeutics, Inc., Irvine, CA) in the endovascular treatment of wide-neck intracranial aneurysms, which have a high rate of incomplete occlusion and recanalization with platinum coils.

METHODS

Sixty-nine patients with 84 aneurysms were treated. Most of the aneurysms were located in the anterior circulation (80 of 84 aneurysms), were unruptured (74 of 84 aneurysms), and were incidental. Ten presented with subarachnoid hemorrhage, and 15 were symptomatic. All aneurysms had wide necks (neck &gt;4 mm and/or dome-to-neck ratio &lt;1.5). Fifty aneurysms were small (&lt;12 mm), 30 were large (12 to &lt;25 mm) and 4 were giant. Angiographic follow-up was available for 65 of the 84 aneurysms at 6 months, for 31 of the 84 aneurysms at 18 months, and for 5 of the 84 aneurysms at 36 months.

RESULTS

Complete aneurysm occlusion was seen in 65.5% of aneurysms on immediate control, in 84.6% at 6 months, and in 90.3% at 18 months. The rates of complete occlusion were 74%, 95.1%, and 95.2% for small aneurysms and 53.3%, 70%, and 80% for large aneurysms at the same follow-up periods. Progression from incomplete to complete occlusion was seen in 68.2% of all aneurysms, with a higher percentage in small aneurysms (90.9%). Aneurysm recanalization was observed in 3 patients (4.6%), with retreatment in 2 patients (3.3%). Procedural mortality was 2.9%. Overall morbidity was 7.2%.

CONCLUSION

Onyx embolization of intracranial wide-neck aneurysms is safe and effective. Morbidity and mortality rates are similar to those of other current endovascular techniques. Larger samples and longer follow-up periods are necessary.

Microscope-integrated near-infrared indocyanine green videoangiography during surgery of intracranial aneurysms: the Helsinki experience

BACKGROUND

Microscope-integrated near-infrared indocyanine green videoangiography (ICG-VA) is a new method of intraoperative blood flow assessment. The objective of this study was to evaluate the reliability of this technique in the evaluation of neck residuals and patency of branches after microneurosurgical clipping of intracranial aneurysms (IAs).

METHODS

During a period of 14 months, between November 2005 and December 2006, 289 patients with intracranial aneurysms were operated on in our institution. Intraoperative ICG-VA was performed during microneurosurgical clipping of 239 IAs in 190 patients. Postoperative computed tomography and computed tomography angiography (CTA) were performed for all patients. Intraoperative interpretation of ICG-VA in assessing the neck residual or the patency of vessels after clipping of each single aneurysm were recorded and correlated with postoperative CTA and/or digital subtraction angiography.

RESULTS

Postoperative imaging studies revealed no incomplete occlusions of aneurysm domes. Unexpected neck residuals were observed in 14 aneurysms (6%). There were no parent artery occlusions. Unexpected branch occlusions including both major and minor branching arteries were observed in 15 aneurysms (6%).

CONCLUSIONS

Indocyanine green videoangiograph is a simple and fast method of blood flow assessment with acceptable reliability. Indocyanine green videoangiograph can provide real-time information to assess blood flow in vessels of different size as well as the occlusion of the aneurysm. Intraoperative assessment of blood flow in the perforating branches is one of the most important advantages. In selected cases such as giant, complex, and deep-sited aneurysms or when the quality of image in ICG-VA is not adequate, other methods of intraoperative blood flow assessment should be considered.

Clinical and angiographic follow-up of ruptured intracranial aneurysms treated with endovascular embolization

BACKGROUND AND PURPOSE

Endovascular embolization is a well-established treatment of ruptured intracranial aneurysms, but concern about its long-term stability and its ability to prevent rehemorrhage are still present. We evaluated the long-term clinical and angiographic follow-up of patients with ruptured cerebral aneurysms treated with coiling, focusing on rehemorrhage and changes in aneurysm morphologic features.

MATERIALS AND METHODS

A total of 377 patients with ruptured aneurysms that were treated with endovascular approaches at our institution between 1994 and 2008 were reviewed. Clinical and angiographic data were analyzed from a prospectively collected data base.

RESULTS

There were 377 patients with 391 ruptured aneurysms treated for 14 years. Good outcome (Glasgow Outcome Score [GOS], 5) was achieved in 74% of patients, moderate disability or poor outcome in 18%, and 8.8% died. Permanent morbidity or mortality from procedural complications occurred in 2.9%. Complete follow-up was available for 85% of surviving patients, with mean follow-up of 22.3 months. Re-treatment was required in 11% (31 patients). Eight (2.1%) patients had rebleeding, 6 (1.6%) in the hospital within 30 days of treatment, 5 in the first 48 hours. Follow-up imaging was available in 276 aneurysms in 270 patients. Recanalization occurred in 56 of 276 aneurysms (20.3%) regardless of the initial angiographic result, but the risk was higher if a body remnant was left (chi2, 11.791; P = .0006).

CONCLUSIONS

Long-term clinical and angiographic follow-up demonstrates the efficacy of endovascular treatment of ruptured intracranial aneurysms. Rebleeding after treatment is rare, with the greatest risk during the first 48 hours after treatment. Initial angiographic results are not a useful predictor of clinical outcome or rehemorrhage.

Treatment of unruptured intracranial aneurysms: surgery, coiling, or nothing?

The decision of whether and how to treat an unruptured intracranial aneurysm (UIA) is complex. The goal in caring for patients with UIAs is to maximize their duration of high-quality life by optimally balancing the risks of aneurysm rupture--the "natural history" of the aneurysm--with those of treatment-related adverse outcomes. In this article, we review the literature concerning the natural history of UIAs and summarize the procedure-associated morbidity and mortality and efficacy of surgical clipping and endovascular coiling. Using this information, we make recommendations regarding the optimal management of patients with UIAs.

Comparison of multislice computed tomography angiography and digital subtraction angiography in the detection of residual or recurrent aneurysm after surgical clipping with titanium clips

PURPOSE

To determine the diagnostic accuracy of 3D-CTA using volume rendering (VR) in the detection of residual or recurrent cerebral aneurysms after clipping.

MATERIAL AND METHODS

Between January 2006 and November 2007, 45 patients (20 female, 25 male) with 50 intracranial aneurysms treated using titanium clips were enrolled in this study. IADSA and 3D-CTA were performed within 1 month after surgery in 27 (60%) patients, after 1 year in 12 (26%) patients and after 5 years in six (13%) patients. In blinded fashion, CTA and DSA images were independently interpreted by two senior neuroradiologists with 7 years of experience in vascular diagnostic neuroradiology. The diagnostic performance of MDCTA compared with DSA for the detection of aneurysm remnants was measured by receiver operating characteristic (ROC) analysis. The area under the ROC curve, 95% confidence interval (CI), sensitivity, and specificity were calculated.

RESULTS

For the detection of residue-recurrent aneurysm; the sensitivity and specificity of MDCTA were 87.5% (95% CI = 52.9-97.8%) and 97.4% (95% CI = 86.5-99.5%) for the first reader and 87.5% (95% CI = 52.9-97.8%) and 100% (95% CI = 90.8-100%) for the second reader respectively. Receiver operating characteristic (ROC) analysis revealed good diagnostic performance for 3D-CTA (mean area under ROC curve (Az) = 0.98 and 0.99 for the first and the second observer, respectively) The kappa values extracted from the interobserver concordance analysis for agreement observers regarding the use of MDCTA for assessment of a remnant neck was 0.62.

CONCLUSION

Using MDCTA, it is possible to demonstrate the status of intracranial aneurysms after surgical clipping in the immediate postoperative period as well as long-term follow-up with an high sensitivity and specificity when comparing with the findings of DSA.

RESULTS, OUTCOMES, AND FOLLOW-UP OF REMNANTS IN THE TREATMENT OF OPHTHALMIC ANEURYSMS

OBJECTIVE

Ophthalmic aneurysms present unique challenges to a vascular team. This study reviews the 16-year experience of a multidisciplinary neurovascular service in the treatment, complications, outcomes, and follow-up of patients with ophthalmic aneurysms from 1990 to 2005.

METHODS

A retrospective analysis of prospectively collected data of 134 patients with 157 ophthalmic aneurysms is presented. Subgroup analysis is performed based on treatment and clinical presentation of the patients.

RESULTS

Clinical outcomes are reported using the Glasgow Outcome Scale. A “good” outcome is defined as a Glasgow Outcome Scale score of 4 or 5, and a “poor” outcome is defined as a Glasgow Outcome Scale score of 1 to 3. Outcome was related to patient age (P = 0.0002) and aneurysm size (P = 0.046). Outcomes for patients with ruptured aneurysms were related to hypertension (P &lt; 0.0001) and clinical admission grade (P = 0.001). In patients with unruptured aneurysms, a good clinical outcome was noted in 103 (92.7%) of 111 patients at discharge and 83 (94.3%) of 88 patients at the time of the 1-year follow-up evaluation. Complete clipping was attained in 89 (79.5%) of 112 patients with angiographic follow-up. Patients with aneurysm remnants from both coiling and clipping had a low risk of regrowth, and there were no rehemorrhages. One of 25 patients with angiographic follow-up (average, 4.3 ± 4.1 years) after “complete” clipping showed recurrence of the aneurysm.

CONCLUSION

Despite the difficulties presented by ophthalmic aneurysms, these lesions can be successfully managed by a multidisciplinary team. Imaging follow-up of patients is important, as there is a risk of aneurysm regrowth after either coiling or clipping.

MR angiography follow-up 5 years after coiling: frequency of new aneurysms and enlargement of untreated aneurysms

BACKGROUND AND PURPOSE

Patients with intracranial aneurysms are at risk for future development of new aneurysms and growth of additional untreated aneurysms. Because in previous long-term studies duration of follow-up varied widely, the time interval after which screening could be effective remains largely unknown. The purpose of this study was to assess the incidence of de novo aneurysm formation and the growth of additional untreated aneurysms in patients with coiled aneurysms followed up with MR angiography (MRA) after a fixed period of 5 years.

MATERIALS AND METHODS

In 65 patients with coiled intracranial aneurysms, high-resolution 3T MRA was performed 5.1 +/- 0.2 years after coiling. MRA follow-up imaging was compared with MRA or CT angiography at the time of coiling. Additional aneurysms detected at MRA follow-up were classified as unchanged, grown, de novo, or incomparable with previous imaging.

RESULTS

In 13 of 65 patients (20%), 24 additional aneurysms were found. Four aneurysms were incomparable with previous imaging and 2 of these were clipped. Of the remaining 20 additional aneurysms, 1 was de novo, 1 had grown slightly, and 18 were unchanged. The incidence of de novo aneurysm formation after 5 years was 1.54% (95% confidence interval, 0.01-9.0%). For additional aneurysms known at the time of initial coiling and for the 1 de novo aneurysm, no treatment was indicated.

CONCLUSIONS

MRA screening 5 years after coiling for detection of de novo aneurysms and growth of additional untreated aneurysms has a low yield in terms of finding aneurysms that need to be treated.

Endovascular histologic effects of ultrathin gold- or vitronectin-coated platinum aneurysm coils in a rodent arterial occlusion model: a preliminary investigation

BACKGROUND AND PURPOSE

Novel stratagems to improve the efficacy of platinum coils in occluding cerebral aneurysms have primarily involved coating coils with materials thought likely to provoke more desirable histologic reactions. No investigations to date, however, have evaluated the utility of gold or vitronectin coatings, despite known endovascular histologic effects of these agents, which may be favorable for treating cerebral aneurysms. This study was conducted to evaluate the degree of endovascular histologic change associated with ultrathin gold- or vitronectin-coated platinum coils. It was hypothesized that such coatings would increase intra-aneurysmal intimal hyperplasia and the degree of luminal occlusion compared with standard platinum coils.

MATERIALS AND METHODS

The ligated carotid artery rat model was used to study 4 different aneurysm coil conditions: no coil (sham-surgery controls), uncoated platinum coil, and gold- or vitronectin-coated platinum coil. Two weeks postimplantation, the aneurysms were harvested and stained with hematoxylin-eosin. Slides were evaluated for the degree of neointimal response by a pathologist blinded to treatment. Additional quantitative evaluation was performed blindly by using the ratio of intimal-to-luminal cross-sectional area.

RESULTS

A gold- or vitronectin-coated platinum aneurysm coil produced a statistically significant increase in neointimal response compared with a sham (no coil). Arterial segments treated with gold-coated platinum coils also demonstrated a statistically significant 100% increase in neointimal response compared with those treated with bare platinum coils.

CONCLUSIONS

In concordance with our hypothesis, ultrathin coatings of gold provoked a neointimal response and degree of luminal occlusion greater than that of plain platinum aneurysm coils in a rat arterial occlusion model.

Post-treatment hemodynamics of a basilar aneurysm and bifurcation

To investigate whether or not a successful aneurysm treatment procedure can subject a parent artery to harmful hemodynamic stresses, computational fluid dynamics simulations are performed on a patient-specific basilar aneurysm and bifurcation before and after a virtual endovascular treatment. Prior to treatment, the aneurysm at systole is filled with a periodic train of vortex tubes, which form at the aneurysm neck and advect upwards into the dome. Following the treatment procedure however, the motion of the vortex train is inhibited by the aneurysm filling material, which confines the vortex tubes to the region beneath the aneurysm neck. Analysis of the post-treatment flow field indicates that the impingement of the basilar artery flow upon the treated aneurysm neck and the close proximity of a vortex tube to the parent artery wall increase the maximum wall shear stresses to values approximately equal to 50 Pa at systole. Calculation of the time-averaged wall shear stresses indicates that there is a 1.4 x 10(-7) m(2) area on the parent artery exposed to wall shear stresses greater than 37.9 Pa, a value shown by Fry [Circ. Res. 22(2):165-197, 1968] to cause severe damage to the endothelial cells that line the artery wall. The results of this study demonstrate that it is possible for a treatment procedure, which successfully isolates the aneurysm from the circulation and leaves no aneurysm neck remnant, to elevate the hemodynamic stresses to levels that are injurious to the artery wall.

Combined endoscope-assisted transclival clipping and endovascular stenting of a basilar trunk aneurysm: case report

OBJECTIVE

We describe a patient with a mid-basilar aneurysm treated with combined endoscope-assisted transsphenoidal clipping and endovascular stenting.

CLINICAL PRESENTATION

A 28-year-old woman was transferred to the cranial base surgery center with an acute Grade III subarachnoid hemorrhage. Cerebral angiography demonstrated a small basilar trunk aneurysm that was not amenable to acute endovascular treatment.

INTERVENTION

The patient underwent sublabial transsphenoidal/transclival endoscope-assisted clipping of the aneurysm and subsequent stenting of the affected segment. The aneurysm was repaired with a low-profile Weck clip (Weck Closure Systems Research, Triangle Park, NC) that permitted a watertight closure of the clival dura using cardiac Medtronic U-clips (Medtronic, Inc., Minneapolis, MN). Postoperatively, the patient had no evidence of cerebrospinal fluid leakage.

CONCLUSION

Watertight dural closure was possible due to the use of a low-profile aneurysm clip that did not protrude through the dural defect, as well as self-tying sutures.