Endovascular repair or surveillance of patients with small AAA.

OBJECTIVE: To compare the outcome of patients with small abdominal aortic aneurysms (AAA) treated in a prospective trial of endovascular aneurysm repair (EVAR) to patients randomized to the surveillance arm of the UK Small Aneurysm Trial. METHOD: All patients with small AAA (< or = 5.5 cm diameter) treated with a stent graft (EVARsmall) in the multicenter AneuRx clinical trial from 1997 to 1999 were reviewed with follow up through 2003. A subgroup of patients (EVARmatch) who met the age (60-76 years) and aneurysm size (4.0-5.5 cm diameter) inclusion criteria of the UK Small Aneurysm Trial were compared to the published results of the surveillance patient cohort (UKsurveil) of the UK Small Aneurysm Trial (NEJM 346:1445, 2002). Endpoints of comparison were aneurysm rupture, fatal aneurysm rupture, operative mortality, aneurysm related death and overall mortality. The total patient years of follow-up for EVAR patients was 1369 years and for UK patients was 3048 years. Statistical comparisons of EVARmatch and UKsurveil patients were made for rates per 100 patient years of follow up (/100 years) to adjust for differences in follow-up time. RESULTS: The EVARsmall group of 478 patients comprised 40% of the total number of patients treated during the course of the AneuRx clinical trial. The EVARmatch group of 312 patients excluded 151 patients for age < 60 or > 76 years and 15 patients for AAA diameter < 4 cm. With the exception of age, there were no significant differences between EVARsmall and EVARmatch in pre-operative factors or post-operative outcomes. In comparison to the UKsurveil group of 527 patients, the EVARmatch group was slightly older (70 +/- 4 vs. 69 +/- 4 years, p = 0.009), had larger aneurysms (5.0 +/- 0.3 vs. 4.6 +/- 0.4 cm, p < 0.001), fewer women (7 vs. 18%, p < 0.001), and had a higher prevalence of diabetes and hypertension and a lower prevalence of smoking at baseline. Ruptures occurred in 1.6% of EVARmatch patients and 5.1% of UKsurveil patients; this difference was not significant when adjusted for the difference in length of follow up. Fatal aneurysm rupture rate, adjusted for follow up time, was four times higher in UKsurveil (0.8/100 patient years) than in EVARmatch (0.2/100 patient years, p < 0.001); this difference remained significant when adjusted for difference in gender mix. Elective operative mortality rate was significantly lower in EVARmatch (1.9%) than in UKsurveil (5.9%, p < 0.01). Aneurysm-related death rate was two times higher in UKsurveil (1.6/100 patient years) than in EVARmatch (0.8/100 patient years, p = 0.03). All-cause mortality rate was significantly higher in UKsurveil (8.3/100 patient years) than in EVARmatch (6.4/100 patient years, p = 0.02). CONCLUSIONS: It appears that endovascular repair of small abdominal aortic aneurysms (4.0-5.5 cm) significantly reduces the risk of fatal aneurysm rupture and aneurysm-related death and improves overall patient survival compared to an ultrasound surveillance strategy with selective open surgical repair.     

Smoking, Lung Function and the Prognosis of Abdominal Aortic Aneurysm

Background the UK Small Aneurysm Trial was established to test the benefit of prophylactic elective surgery for small abdominal aortic aneurysms (4.0–5.5 cm in diameter) and identify prognostic risk factors, including smoking. Patients, methods and outcomes one thousand and ninety patients (902 men and 188 women, mean age 69.3 years) were randomised to either early elective surgery or ultrasonography surveillance until the aneurysm diameter exceeded 5.5 cm, mean follow-up was 4.6 years. Baseline assessments included lung function tests and cotinine (a smoking marker). The principal outcome measures were all-cause mortality and aneurysm rupture. Results during the course of the trial, aneurysm rupture was diagnosed in 25 patients and 309 patients died. Whereas self-reported smoking status was not significantly associated with survival, patients without any trace of plasma cotinine had a significantly improved long-term (6-year) survival,p =0.02. Current smokers had a lower FEV₁than past- and never-smokers. FEV₁was the most powerful predictor of long-term (6-year) survival, the crude death rates per 100 person-years were 9.1, 6.9 and 4.6 for those with FEV₁<1.9 l, 1.9–2.5 l and >2.5 l respectively, p=0.001. Moreover, the rupture rate was 1.9% per year for patients positive for plasma cotinine compared with 0.5% in those without trace of plasma cotinine,p =0.004. Conclusions self-reported smoking status underestimates the effect of continued smoking on the prognosis of patients with small abdominal aortic aneurysm. Patients with high plasma cotinine concentrations (smokers) have an increased risk of aneurysm rupture and poorer long-term survival.     

Are we Ignoring the Importance of Ankle Pressures in Patients with Abdominal Aortic Aneurysm?

BACKGROUND AND PURPOSE: the ankle/brachial pressure index (ABPI) has been shown to be a reliable marker of cardiovascular risk in population studies. We investigated whether the ABPI was a useful prognostic index for patients with abdominal aortic aneurysm. METHODS: patients entered into the U.K. Small Aneurysm Trial and Study had their ABPI measured in both legs at baseline (mean ABPI reported) and were followed up until 30 June 1998, with information about cause of death being obtained from the Office of National Statistics. This study focussed on cardiovascular and all-cause mortality. RESULTS: a total of 1827 men and 478 women, mean age 69 years, median aneurysm diameter 4.4 cm, were followed up for a median of 5.7 years. A total of 829 deaths were reported (rate 8.1 per 100 person-years), 546 (66%) from cardiovascular causes. The all-cause mortality risk increased as the ABPI decreased, hazard ratio 1.25 per 0.2 unit decrease in ABPI (95% CI 1.17 to 1.34, p<0.001). For patients in the lowest tertile group (ABPI <0.87) there were 11.6 deaths per 100 person-years. This increased risk persisted after adjustment for age, sex, evidence of ischaemia on resting ECG and initial aneurysm diameter, adjusted hazard ratio 1.17 per 0.2 unit decrease in ABPI (95% CI 1.07 to 1.28, p<0.001). CONCLUSION: the ankle/brachial pressure index is an important prognostic indicator for patients with abdominal aortic aneurysm. Patients with an ABPI below 0.87 (limit of lowest tertile) have the highest mortality risk and best clinical practice demands that attention is focussed on active treatment to minimise their cardiovascular risk factors.     

Influence of sex on expansion rate of abdominal aortic aneurysms

BACKGROUND: The UK Small Aneurysm Trial suggested that female sex is an independent risk factor for rupture of abdominal aortic aneurysm (AAA). This study assessed the effect of sex on the growth rate of AAA. METHODS: Between January 1985 and August 2005 all patients who were referred to the Royal Infirmary of Edinburgh with an AAA who were not considered for early aneurysm repair were assessed by serial abdominal ultrasonography. Maximum anteroposterior and transverse diameters of the AAAs were measured. RESULTS: A total of 1255 patients (824 men and 431 women) were followed up for a median of 30 (range 6-185) months. A median of six examinations (range 2-37) was performed for each patient. Median diameter on initial examination was 41 (range 25-83) mm. Median growth rate overall was 2.79 (range - 4.80-37.02) mm per year. Median growth rate of AAA was significantly greater in women than men (3.67 (range - 1.2-37.02) versus 2.03 (range - 4.80-21.00) mm per year; P < 0.01). Weighted linear regression analysis revealed that large initial anteroposterior AAA diameter and female sex were significant predictors of faster aneurysm growth rate (P < 0.001 and P = 0.006 respectively). CONCLUSION: The growth rate of AAA was significantly greater in women than in men. This may have implications for the frequency of follow-up and timing of repair of AAA in women.     

Ultrasonographic screening for abdominal aortic aneurysm.

OBJECTIVE--To assess the prevalence of abdominal aortic aneurysm in a selected group of men over the age of 60, and define main risk factors. DESIGN--Population based screening study. SETTING--Private Norwegian health maintenance organisation. SUBJECTS--500 men over the age of 60 years. INTERVENTIONS--General examination by a general practitioner, together with measurements of blood glucose and serum cholesterol concentrations. Abdominal scan with a B-mode ultrasound imager. MAIN OUTCOME MEASURES--An increase in the diameter of the aorta of more than 150% over the diameter at the origin of the superior mesenteric artery, or maximum diameter of more than 29 mm. Correlation with history of smoking, serum cholesterol concentration, and general health. RESULTS--29 patients (5.8%) had small, and 12 (2.4%) had large, abdominal aortic aneurysms. There was a significant association between aortic aneurysm and history of smoking (p < 0.01), poor health (defined as coexistent hypertension, cardiovascular disease, or diabetes mellitus) (p < 0.01), and increasing age (p = 0.025). There was no association with hypercholesterolaemia. CONCLUSION--Ultrasonic screening of groups at risk followed by elective operation may reduce mortality of abdominal aortic aneurysm.     

Surgery for aortic aneurysms

Aortic aneurysms, the majority of which affect the infrarenal abdominal portion of the aorta, are responsible for 1–2% of all deaths in men aged over 65 years in the Western world. The disease most commonly represents a multifactorial degenerative process involving both genetic and environmental risk factors and is characterized pathologically by a reduction in elastic lamellae within the aortic wall. The natural history of the condition is one of progressive enlargement with an associated increase risk of aneurysm rupture. Although aneurysm rupture remains a catastrophic event, with an overall mortality of approximately 80%, the majority of patients are asymptomatic. Asymptomatic aneurysms are usually diagnosed as an incidental finding and management relies on an assessment of the risks of future aneurysm rupture weighed against the risks associated with elective surgical repair. Aneurysm repair may be accomplished by traditional open surgery or minimally invasive endovascular repair. Although the latter confers a short-and medium-term survival advantage in selected patients, long-term follow-up data suggest this benefit may not persist. Thoracoabdominal aortic aneurysm disease is considerably more complex, with intervention, even in specialist centres, associated with significant morbidity and mortality. Best medical management of aortic aneurysm disease requires control of blood pressure, smoking cessation together with aspirin and statin therapy. Screening has been introduced in an effort to identify a largely silent killer although with better medical management the overall prevalence may be in decline.     

Long-term results of endovascular abdominal aortic aneurysm treatment with the first generation of commercially available stent grafts

HYPOTHESIS: Little information about the long-term results of endovascular abdominal aortic aneurysm repair is available. This study was performed to evaluate the long-term data of patients treated with the first generation of commercially available stent grafts. DESIGN: Multicenter registry. SETTING: Sixty-two European centers that participated in the EUROSTAR (EUROpean collaborators on Stent-graft Techniques for abdominal aortic Aneurysm Repair) registry. PATIENTS: A total of 1190 patients with a follow-up of up to 8 years, who underwent endovascular abdominal aortic aneurysm repair with a stent graft (Stentor or Vanguard). INTERVENTION: Elective endovascular abdominal aortic aneurysm repair. MAIN OUTCOME MEASURES: The morbidity and mortality data of patients treated with the first-generation stent graft who enrolled in the EUROSTAR registry were analyzed. Incidence rates of complications were calculated to quantify annual risks. Life-table analyses and multivariate Cox proportional hazards models were used for the survival analysis. RESULTS: Conversion to open repair, aneurysm rupture, all-cause death, and aneurysm-related death occurred in 7.1%, 2.4%, 19.9%, and 3.0% of the patients, respectively. The cumulative percentage of the combined outcome event, conversion-free and rupture-free survival, after 8 years was 48.0%. Procedure-related complications that frequently occurred were endoleak (13.0 cases per 100 patient-years), stenosis/thrombosis (4.6 cases per 100 patient-years), and stent migration (4.3 cases per 100 patient-years). CONCLUSIONS: Patients treated with the first generation of stent grafts will need lifelong surveillance because of a considerable risk of late complications. How these findings translate to the outcome of newer-generation stent grafts is unknown. For this reason, vigilant surveillance remains indicated in all patients who undergo endovascular abdominal aortic aneurysm repair.     

Natural history of abdominal aortic aneurysm: A survey of 63 patients treated nonoperatively

During a 10-year period in which 735 patients presented with abdominal aortic aneurysms to our clinic, 63 were not offered operative treatment. The primary reason for choosing conservative treatment was concomitant diseases that increased the risk of operation. After 2 years of follow-up, half of the patients died, and the cumulative 5-year survival rate was 15%. Aneurysm rupture was the primary cause of death. The cumulative 5-year mortality hazard rate from rupture was 0.36, corresponding to an annual risk of rupture of 7%. The cumulative 5-year hazard rate of death from all other causes was 1.53, corresponding to an annual risk of 30%. Diameter of the aneurysm was found to be the only factor with a significant impact on the rate of rupture. The cumulative 5-year hazard rate of rupture among patients with aneurysms <6 cm and 6 cm was 0.2 and 0.6, respectively, corresponding to an annual risk of rupture of less than 5% and 10% to 15%, respectively. However, neither diameter nor other risk factors had significant influence on the time of rupture. In our opinion, once the diagnosis is confirmed the patient should be offered aneurysm resection if the general health status permits anesthesia.     

The evolving technique of endovascular stenting of abdominal aortic aneurysm; time for reappraisal.

PURPOSE: to investigate the occurrence of intra-operative device-related complications during stent-grafting for abdominal aortic aneurysm. MATERIALS AND METHODS: data on patient characteristics, vascular morphology, operative technical details, procedural and device-related complications were obtained from the European collaborators on stent-graft techniques for abdominal aortic aneurysm repair (EUROSTAR) registry. Only intra-operative device-related complications were taken into account. Potential risk factors for device-related complications were examined by logistic regression analysis. The association between these complications and conversion to open surgery and death were determined. RESULTS: between January 1994 and July 2000, 2862 patients in 90 participating hospitals underwent endovascular abdominal aortic aneurysm repair. Device-related complications occurred in 238 (8.3%) patients. Complications were associated with the age of the patient (p=0.002), gender (p=0.05), smoking habit (p=0.001), pre-operative aneurysm diameter (p=0.005), type of device implanted (p=0.0001), fitness of the patient for open surgery (p=0.002), and year of operation (p=0.001). Adjusted for risk factors, the occurrence of complications decreased between 1994 to 2000 from 21.7% to 7.3%, respectively. Patients with device-related complications were 13.6 times (95% CI; 9.2-20.1) more likely to have conversion to an open procedure and 2.4 times (95% CI; 1.4-4.0) more likely to die within 30 days of the operation. CONCLUSIONS: intra-operative device-related complications were common, although appear to be decreasing in frequency, and were significantly related to conversion and post-operative death.     

The natural history of abdominal aortic aneurysms

This study examines the rate of expansion of abdominal aortic aneurysms and the risk of rupture in relation to their size. To assess these variables, we conducted a prospective study of 300 consecutive patients who presented over a 6-year interval with abdominal aortic aneurysms (AAA) that were initially managed nonoperatively. The mean age of the patients was 70.4 years, and 211 (70%) were men. The mean initial aneurysm diameter was 4.1 cm. Among the 208 patients who underwent more than one ultrasound or computed tomographic (CT) scan, the diameter of the aneurysm increased by a median of 0.3 cm per year. The 6-year cumulative incidence of rupture was 1% and 2% among patients with aneurysms less than 4.0 cm and 4.0 to 4.9 cm in diameter, respectively (p greater than 0.05). In comparison, the 6-year cumulative incidence of rupture was 20% among patients with aneurysms greater than 5.0 cm in diameter (p less than 0.004). We conclude that (1) abdominal aortic aneurysms expand at a median rate of 0.3 cm per year; and (2) the risk of rupture of abdominal aortic aneurysms less than 5.0 cm is substantially lower than the risk of rupture of aneurysms 5.0 cm or more in diameter.     

Open Repair for Ruptured Abdominal Aortic Aneurysm: Is It Possible to Predict Survival?

The aim of the study was to determine variables that could be used to predict survival in patients with ruptured abdominal aortic aneurysm (RAAA) and to assess the accuracy of the Glasgow Aneurysm Score (GAS) and the Acute Physiology Chronic Health Evaluation II (APACHE-II). From January 1998 to July 2006, 103 patients underwent operations for RAAA. For each patient, 44 variables were retrospectively recorded in a database. Data were analyzed with univariate and multivariate methods. In the univariate analysis significant predictors of death were hypotension (p=0.001), preexisting peripheral vascular disease (p<0.001), renal insufficiency (p=0.037), chronic obstructive pulmonary disease (p=0.028), level of HCO(3)(-) (p<0.001), intraperitoneal rupture (p=0.001), blood transfused (p<0.001), cardiac complications (p<0.001), and APACHE-II score (p=0.001). Multivariate analysis confirmed statistical significance for coexisting peripheral vascular disease (p<0.001), diastolic blood pressure at admission <60 mm Hg (p=0.039), APACHE-II score >18.5 (p=0.025), HCO(3)(-) <21 mg/dL (p<0.001), and intraperitoneal rupture of the aneurysm (p=0.011) as predictors of death. Results of the study suggested that different factors can be helpful in identifying those patients whose operative risk is prohibitive. APACHE-II, contrary to GAS, is an accurate system to predict postoperative death after repair for RAAA.     

Human leukocyte antigen class II immune response genes,female gender,and cigarette smoking as risk and modulating factors in abdominal aortic aneurysms

OBJECTIVE: Aortic inflammation and the genes that regulate the immune response play an important role in abdominal aortic aneurysm pathogenesis. However, the modulating effects of such genetic and other environmental factors on the severity on aneurysm inflammation is not known. The objective of this study was to determine the influence of the human leukocyte antigen (HLA) class II genes, gender, and environmental factors on degree of abdominal aortic aneurysm tissue inflammation. METHODS: Aneurysm specimens were obtained at the time of operation from 96 consecutive patients who underwent abdominal aortic aneurysm repair and were graded for degree of histologic inflammation. Multivariate analysis was used to determine the association of genetic and environmental factors with degree of inflammation and to determine the HLA-associated disease risk for aneurysm. RESULTS: Active cigarette smoking and female gender were independently associated with high-grade tissue inflammation identified histologically (odds ratio [OR], confidence interval [CI]: 5.6, 1.6 to 19.3; and 6.0, 1.4 to 26.2, respectively), and a specific HLA allele (DR B1(*)01) was inversely associated with inflammation (OR, CI: 0.2, 0.04 to 0.7). Overall, the HLA-DR B1(*)02 and B1(*)04 alleles were significantly associated with disease risk, more than doubling risk for abdominal aortic aneurysm (OR, CI: 2.5, 1.4 to 4.3; and 2.1, 1.2 to 3.7, respectively). CONCLUSION: Active cigarette smoking and female gender are significant disease-modulating factors associated with increased abdominal aortic aneurysm inflammation. In addition, the HLA class II immune response genes possess both disease modulating and disease risk properties, which may be useful in early aneurysm detection and surveillance.     

Simulations of the effects of scheduled abdominal aortic aneurysm repair on survival

I simulated survival with and without scheduled repair of abdominal aortic aneurysms with different diameters in different populations. The results imply that scheduled repair should be determined by the combination of a patient's monthly mortality hazard and aneurysm diameter. The median survival of some patients will be extended by the scheduled repair of aneurysms smaller than 55 mm, whereas the median survival of other patients will be curtailed by repair of any aneurysm. The results also suggest that, on average, surveillance is futile: the effect of scheduled aneurysm repair on an individual's median survival did not change but the cohort effect diminished as patients died during surveillance. The results of the UK Small Aneurysm Study were reproduced in simulation and are compatible with the repair of aneurysms smaller than 55 mm diameter. Epidemiological simulations suggest that past randomised controlled trials underestimate the effect of aneurysm repair today.     

Risk factors for endoleak and the evidence for stent-graft oversizing in patients undergoing endovascular aneurysm repair.

OBJECTIVES: the aim of this study was to assess the relationship between patient factors, the anatomy of the proximal aneurysm neck; the type of endovascular graft; and the consequences of graft/neck size mismatch and the occurrence of proximal endoleak. Design multicentre clinical study. MATERIALS: of a total of 2194 patients, 2146 underwent successful endovascular repair of infra-renal abdominal aortic aneurysms (AAA). METHODS: endoleaks were identified by radiological imaging immediately after completion of the procedure as per study protocols. Clinical and anatomical features of AAA in patients with endoleak were compared to patients without endoleak and data were analysed using the Chi-square test. A multivariate logistic regression model was constructed by selecting variables found to be significantly associated with complications in a univariate analysis. RESULTS: intra-operative endoleak was observed in 16.7% overall, and 3.3% were noted to have proximal endoleak. Aneurysm size larger than 60 mm (p =0.004), ex-smokers ( p =0.005) and age over 75 years ( p =0.01) were independently associated with endoleak of all types. Univariate and multivariate analysis revealed correlation between proximal endoleak and (i) diameter of the aneurysm neck-proximal (D2a), middle (D2b), distal (D2c), at all levels (p <0.005); (ii) proximal aortic neck length ( p =0.0001); (iii) aortic device diameter ( p =0.0024). No correlation was identified for angulation and form of the aortic neck. A model of the frequency of proximal endoleak, in relation to the ratio of the aortic device diameter to the distal aortic neck diameter, revealed that endoleak decreased when the aortic device diameter became oversized by more than 10% and confidence intervals remained tight for up to and over 20% oversize.     

True juxta-anastomotic aneurysms in the residual infra-renal abdominal aorta.

INTRODUCTION: abdominal aortic dilatation can occur above the graft following repair of infra-renal abdominal aortic aneurysm (AAA). This study aimed to determine the incidence and possible aetiological associations of recurrent juxta-anastomotic aneurysms following open repair of AAA. METHODS: the diameter of the infra-renal aorta above the graft of 135 patients who had previously undergone open AAA repair was determined using ultrasound. In those where the diameter was greater than 40 mm a CT scan was undertaken. Co-morbid and operative details were determined from the patients and their clinical notes. RESULTS: seven patients had true juxta-anastomotic aneurysms (>40 mm) in the residual infra-renal abdominal aorta, the occurrence of which was associated with tobacco smoking and hypertension. There was no association with other co-morbid factors, surgical operative details or the development of iliac aneurysms (which occurred in 3% of patients). CONCLUSIONS: true juxta-anastomotic aneurysms develop in the residual infra-renal neck of patients following open repair of abdominal aortic aneurysm. Tobacco smoking and hypertension are significant factors associated with the development of these aneurysms. This group of patients may warrant surveillance to prevent aneurysm rupture.     

Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture

OBJECT: The authors conducted a study to investigate the long-term natural history of unruptured intracranial aneurysms and the predictive risk factors determining subsequent rupture in a patient population in which surgical selection of cases was not performed. METHODS: One hundred forty-two patients with 181 unruptured aneurysms were followed from the 1950s until death or the occurrence of subarachnoid hemorrhage or until the years 1997 to 1998. The annual and cumulative incidence of aneurysm rupture as well as several potential risk factors predictive of rupture were studied using life-table analyses and Cox's proportional hazards regression models including time-dependent covariates. The median follow-up time was 19.7 years (range 0.8-38.9 years). During 2575 person-years of follow up, there were 33 first-time episodes of hemorrhage from previously unruptured aneurysms, for an average annual incidence of 1.3%. In 17 patients, hemorrhage led to death. The cumulative rate of bleeding was 10.5% at 10 years, 23% at 20 years, and 30.3% at 30 years after diagnosis. The diameter of the unruptured aneurysm (relative risk [RR] 1.11 per mm in diameter, 95% confidence interval [CI] 1-1.23, p = 0.05) and patient age at diagnosis inversely (RR 0.97 per year, 95% CI 0.93-1, p = 0.05) were significant independent predictors for a subsequent aneurysm rupture after adjustment for sex, hypertension, and aneurysm group. Active smoking status at the time of diagnosis was a significant risk factor for aneurysm rupture (RR 1.46, 95% CI 1.04-2.06, p = 0.033) after adjustment for size of the aneurysm, patient age, sex, presence of hypertension, and aneurysm group. Active smoking status as a time-dependent covariate was an even more significant risk factor for aneurysm rupture (adjusted RR 3.04, 95% CI 1.21-7.66, p = 0.02). CONCLUSIONS: Cigarette smoking, size of the unruptured intracranial aneurysm, and age, inversely, are important factors determining risk for subsequent aneurysm rupture. The authors conclude that such unruptured aneurysms should be surgically treated regardless of their size and of a patient's smoking status, especially in young and middle-aged adults, if this is technically possible and if the patient's concurrent diseases are not contraindications. Cessation of smoking may also be a good alternative to surgery in older patients with small-sized aneurysms.     

Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture

OBJECT: The authors conducted a study to investigate the long-term natural history of unruptured intracranial aneurysms and the predictive risk factors determining subsequent rupture in a patient population in which surgical selection of cases was not performed. METHODS: One hundred forty-two patients with 181 unruptured aneurysms were followed from the 1950s until death or the occurrence of subarachnoid hemorrhage or until the years 1997 to 1998. The annual and cumulative incidence of aneurysm rupture as well as several potential risk factors predictive of rupture were studied using lifetable analyses and Cox's proportional hazards regression models including time-dependent covariates. The median follow-up time was 19.7 years (range 0.8-38.9 years). During 2575 person-years of follow up, there were 33 first-time episodes of hemorrhage from previously unruptured aneurysms, for an average annual incidence of 1.3%. In 17 patients, hemorrhage led to death. The cumulative rate of bleeding was 10.5% at 10 years, 23% at 20 years, and 30.3% at 30 years after diagnosis. The diameter of the unruptured aneurysm (relative risk [RR] 1.11 per mm in diameter, 95% confidence interval [CI] 1-1.23, p = 0.05) and patient age at diagnosis inversely (RR 0.97 per year, 95% CI 0.93-1, p = 0.05) were significant independent predictors for a subsequent aneurysm rupture after adjustment for sex, hypertension, and aneurysm group. Active smoking status at the time of diagnosis was a significant risk factor for aneurysm rupture (RR 1.46, 95% CI 1.04-2.06, p = 0.033) after adjustment for size of the aneurysm, patient age, sex, presence of hypertension, and aneurysm group. Active smoking status as a time-dependent covariate was an even more significant risk factor for aneurysm rupture (adjusted RR 3.04, 95% CI 1.21-7.66, p = 0.02). CONCLUSIONS: Cigarette smoking, size of the unruptured intracranial aneurysm, and age, inversely, are important factors determining risk for subsequent aneurysm rupture. The authors conclude that such unruptured aneurysms should be surgically treated regardless of their size and of a patient's smoking status, especially in young and middle-aged adults, if this is technically possible and if the patient's concurrent diseases are not contraindications. Cessation of smoking may also be a good alternative to surgery in older patients with small-sized aneurysms.     

Should abdominal aortic aneurysm be managed differently in women?

Although abdominal aortic aneurysm (AAA) is 4 to 6 times more common in men than in women, more than a third of all AAA deaths occur in women. In several reports from the UK Small Aneurysm Trial group, the rupture rate for women was 3-4 times that seen in men. A joint council of several vascular societies responded to these observations with the recommendation that AAA should be repaired earlier in women, at 4.5 cm to 5.0 cm rather than the 5.5 cm established in randomized trials for men. However, this recommendation does not appear to reflect a full consideration of the evidence. For example, population-based studies have reported mortality following AAA repair to be 40-60% higher in women than in men. Also, in the UK Small Aneurysm Trial itself, there was no trend toward a benefit from early repair in women. The totality of evidence available at present provides no good reason to alter for women the 5.5 cm threshold for elective repair established for men by the small AAA trials.     

Abdominal aortic aneurysm: epidemiology,screening and work-up for repair

Abdominal aortic aneurysm (AAA) is a dilatation of the infra-renal abdominal aorta to greater than 3 cm. Population screening is offered to men in the year of their 65th birthday in the UK. Patients with small, asymptomatic AAAs (<5.5 cm) are entered into surveillance programmes and have their cardiovascular risk factors managed aggressively. An AAA ≥5.5 cm diameter, or one which is symptomatic, should be considered for surgical repair to prevent rupture. Aneurysm repair can be undertaken using either an open surgical or endovascular approach; the decision should be tailored to the individual patient and made by the surgeon and patient, with input from a multi-disciplinary team.     

Treatment for intracranial aneurysms

Aneurysm rupture is suspected in case of sudden, intense headache, sometimes associated with nausea or vomiting, focal neurologic deficit or loss of consciousness. Aneurysm rupture is a diagnostic and therapeutic emergency that has to be managed in highly specialized centers. Ruptured aneurysms have to be treated in emergency to avoid rebleeding. Endovascular approach is the first line treatment. The indications for treatment of unruptured have to be discussed according to several factors including patient's age, aneurysm size and location. Follow-up examinations are needed after aneurysm treatment (CTA, MRA, DSA). According to aneurysm risk factors, patients with aneurysms have to stop smoking and their blood pressure should be controlled on a regular basis and treated if needed.