Unruptured aneurysms

Anévrismes intracrâniens non rompus : que proposer ?

Intracranial unruptured aneurysm (ICUA) has become a common condition for patient consultation. The mortality rate after fissuration is estimated to be between 52% and 85.7%. The final therapeutic decision results from a balance between the risk of rupture and risks related to the aneurysmal exclusion. Analysis of the risk of rupture risk enables a classification of risk factors. Depending on the circumstances of diagnosis, we considered the ICUA at high risk of rupture for incidental ICUA larger than 7 mm and in the event of associated aneurysms. Classifying by morphologic features, high-risk ICUA were located in the vertebrobasilar system (RR: 4.4; 95%CI: 2.7-6.8), those with a size between 7 and 12 mm (RR: 3.3; 95%CO: 1.3-8.2), larger than 12 mm (RR: 17; 95%CI: 8-36.1), those that were multilobular or a larger size and those ones with a index P/L superior to 3.4 (risk x20). Familial ICUA would expose to a major rupture risk (2 to 7 times sporadic ICUA). Some systemic factors were related to ICUA rupture: arterial hypertension (RR: 1.46; 95%CI: 1.01-2.11) and smoking addiction (RR: 3.04; 95%CI: 1.21-7.66). After microsurgical exclusion, the morbidity and mortality rates were 10% and 2% respectively. Some microsurgical morbidity factors were identified: age (32%>65 years), size (14%>15 mm), vertebrobasilar location and temporary occlusion. The rupture incidence after microsurgical exclusion was estimated 0.26%/year. After endovascular exclusion, the morbidity and mortality rates were 8% and 1% respectively. The complete exclusion rate varied between 47% and 67%. The rupture risk was estimated at 0.9%/year. Treatment recommendations were classified into 3 categories.

A randomized trial on the safety and efficacy of endovascular treatment of unruptured intracranial aneurysms is feasible

SUMMARY

The safety and efficacy of endovascular treatment of unruptured intracranial aneurysms remain undetermined. A randomized trial may be the best way to demonstrate the potential benefits of endovascular management. We propose a randomized, prospective, controlled trial comparing the incidence of subarachnoid haemorrage of patients treated by endovascular coiling as compared to conservative management. We would also study a composite outcome combining SAH and the morbidity of treatment. All patients with one or more unruptured aneurysm >> 3 mm eligible for endovascular treatment would be proposed to participate. The study would be conducted in 40-50 centres. The entire study would enrol 1800 patients, recruited over three years and followed for five years, but would be preceded by a feasibility study on 200 patients. A randomized trial comparing endovascular and conservative treatment could have an important impact on the clinical management of intracranial aneurysms.

Anatomical and clinical outcomes after endovascular treatment for unruptured cerebral aneurysms. A single-center experience

SUMMARY

To describe the immediate and follow-up anatomical outcomes as well as procedure-related morbidity after endovascular procedures for unruptured cerebral aneurysms, we reviewed 68 patients with 78 unruptured aneurysms treated with detachable coils from may 1996 to february 2002. Angiograms were retrospectively reviewed for the nature of the aneurysms and the degree of therapeutic obliteration. Periprocedural complications, immediate clinical outcome and longterm neurological status were analyzed. Immediate anatomical outcomes were complete in 35 aneurysms (45%); residual neck in 24 (31%), partial contrast filling in 17 (22%), and failed embolization in two (2%). Of 27 aneurysms with follow-up angiography, 12 of the 13 aneurysms that were completely occluded in the initial treatment were still completely occluded at the end of a mean follow-up period of 17 months. Periprocedural complications were thromboembolic (n=6), haemorrhagic (n=3), coil protrusion (n=7) and other unrelated complications (n=3). Only two patients, with thromboembolic complications were moderately disabled with permanent neurological deficits in immediate clinical outcome, and their condition improved to independent in 1.5 and three months each. Small aneurysms and posterior circulation location showed more protective immediate results than aneurysms of large and anterior circulation after endovascular treatment (p values: 0.01 and 0.02). Our experiences of endovascular treatment for unruptured cerebral aneurysms were comparable to the results of recent series. Endovascular treatment for small posteriorly located aneurysms produced significantly better results than for large anteriorly located lesions.

Investigation of the surgically treated and untreated unruptured cerebral aneurysms of the anterior circulation

BACKGROUND

The natural history of unruptured cerebral aneurysms and the surgical risks are modified by several factors including size, location, and presence of subarachnoid hemorrhage (SAH). The main confusion arises because the backgrounds of the past reports describing the natural history or the surgical complication of unruptured cerebral aneurysms were different. The present study aimed to adjust the backgrounds and investigate the surgical indication with close monitoring of both surgically treated and untreated unruptured cerebral aneurysms.

METHODS

In the past 9 years, 201 patients who had unruptured anterior circulation aneurysms were monitored. The decision of the operation was not randomized. The patients were divided into three subgroups by the size of the aneurysms (small group: below 5 mm, medium group: between 5 and 15 mm, large group: over 15 mm). In both surgically untreated and treated patients, overall mortality and morbidity corresponding to Rankin score II or worse was counted as unruptured aneurysm related event. The ratio of event free was compared between surgically treated and untreated patients using Log-rank test.

RESULTS

In untreated patients, SAH was noted in 1 in the small group and 4 in the medium group. The annual rupture rate of the medium group was 12 times higher than that of the small group. In surgically treated patients, overall mortality and morbidity of the surgery was 2.3% in the small group, 3.6% in the medium group, and 20% in the large group. One surgically treated patient had SAH because of regrowth of aneurysm. When ratio of event free was compared, no significant advantage of surgery was noted in the small group and in all of the patients. However, the benefit of surgery was significant in the medium group (Log-rank p = 0.0189).

CONCLUSIONS

The present results indicated that prophylactic surgery has a benefit for the medium-size aneurysms (5-15 mm) of the anterior circulation. For large aneurysms, individual investigation is necessary because of the variety of surgical difficulties, and the complex symptoms because of rupture and the mass effect as well as cerebral embolism. In small aneurysms, careful observation may be a reasonable choice unless the aneurysm is at a specially high risk of rupture.

Prevalence of asymptomatic incidental aneurysms: review of 4568 arteriograms

OBJECT

The prevalence of unruptured cerebral aneurysms is unknown, but is estimated to be as high as 5%. The goal of this study was to determine the prevalence of asymptomatic incidental aneurysms.

METHODS

The authors studied all cerebral arteriography reports produced at a single institution, the University of Virginia, between April 1969 and January 1980. A review of 3684 arteriograms demonstrated 24 cases of asymptomatic aneurysms, yielding a prevalence rate of 0.65%. The majority (67%) of the 24 patients harboring unruptured aneurysms were women. More than 90% of the unruptured aneurysms were located in the anterior circulation and in locations similar to those found in patients with ruptured aneurysms. Nearly 80% of the aneurysms were smaller than 1 cm in their greatest diameter. The frequency of asymmetrical unruptured aneurysms (0.6-1.5%) was constant throughout all relevant age ranges (35-84 years).

CONCLUSIONS

While keeping in mind appropriate caveats in extrapolating from these data, the prevalence rate of asymptomatic unruptured aneurysms found in the present study allows an estimation of the yearly rate of rupture of these lesions. The authors suggest that this yearly rate of rupture falls within the range of 1 to 2%.

Vascular complications in anterior thoracolumbar spinal reconstruction

OBJECT

Anterior approaches in thoracic and lumbar spinal surgery have potentially serious vascular injury-related complications. In this study the authors evaluate the incidence of vascular complications in anterior approaches to the thoracic and lumbar spine in cases requiring reconstructive surgery.

METHODS

The authors retrospectively reviewed the medical records of 207 patients who underwent anterior thoracic and lumbar spinal reconstructive surgery during the period from 1992 through 1999 to determine the incidence, causes, and management of vascular complications. Overall, the incidence of vascular complications following reconstructive spinal surgery was 5.8% (12 patients) and the mortality rate was 1% (two patient deaths). In seven patients (3.4%), direct vascular injuries developed as a result of surgical techniques or error; one patient died as a result. Five patients (2.4%) developed deep venous thromboses, and one patient in this subgroup died of pulmonary embolism.

CONCLUSIONS

Vascular injury to the great vessels is a known and potentially serious complication associated with anterior spinal reconstructive procedures. The authors found, however, that the incidence is relatively low in cases in which venous injuries occurred acutely and arterial injuries presented in a delayed fashion.