Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial

Anemia is associated with abdominal aortic aneurysm (AAA) size and decreased long-term survival after endovascular AAA repair

OBJECTIVE

Anemia is a common comorbid condition in various inflammatory states and an established predictor of mortality in patients with chronic heart failure, ischemic heart disease, and end-stage renal disease. The present study of patients with abdominal aortic aneurysm (AAA) undergoing endovascular repair (EVAR) assessed the relationships between baseline hemoglobin concentration and AAA size, as well as anemia and long-term survival.

METHODS

Between March 1994 and November 2006, 711 patients (65 women, mean age 75.8 +/- 7.8 years) underwent elective EVAR. Anemia was defined as a hemoglobin level <13 g/dL in men and <12 g/dL in women. Post-EVAR mean follow-up was 48.3 +/- 32.0 months. Association of hemoglobin level with AAA size was assessed with multiple linear regression. Mortality was determined with use of the internet-based Social Security Death Index and the electronic hospital record. Kaplan-Meier survival curves of anemic and nonanemic patient groups were compared by the log-rank method. Multivariable logistic regression models were used to determine the influence of anemia on vital status after EVAR.

RESULTS

A total of 218/711 (30.7%) of AAA patients undergoing EVAR had anemia at baseline. After adjustment for various risk factors, hemoglobin level was inversely related to maximum AAA diameter (beta: - .144, 95%-CI: -1.482 - .322, P = .002). Post-EVAR survival was 65.5% at 5 years and 44.4% at 10 years. In long-term follow-up, survival was significantly lower in patients with anemia as compared to patients without anemia (P < .0001 by log-rank). Baseline hemoglobin levels were independently related to long-term mortality in multivariable Cox regression analysis adjusted for various risk factors (adjusted HR: 0.866, 95% CI: .783 to .958, P = .005). Within this model, statin use (adjusted HR: .517, 95% CI: .308 to .868, P = .013) was independently related to long-term survival, whereas baseline AAA diameter (adjusted HR: 1.022, 95% CI: 1.009 to 1.036, P = .001) was an independently associated with increased mortality.

CONCLUSIONS

Baseline hemoglobin concentration is independently associated with AAA size and reduced long-term survival following EVAR. Thus, the presence or absence of anemia offers a potential refinement of existing risk stratification instruments.

Long-term durability of open abdominal aortic aneurysm repair

OBJECTIVE

In multiple comparisons of open vs endovascular (EVAR) repair of abdominal aortic aneurysms, the prior assumption that open repair produced superior durability has been challenged by advocates of EVAR. Although focus on EVAR reintervention has been intense, few contemporary studies document late outcomes after open repair; this was the goal of this study.

METHODS

From January 1994 to December 1998 (chosen to ensure a minimum 5-year follow-up), 540 patients underwent elective open repair. Surveillance imaging (computed tomographic and magnetic resonance imaging scans) was obtained for 152 (57%) of the 269 patients who remained alive at a mean follow-up of 87 months. Study end points included freedom from graft-related interventions and aneurysm-related and overall survival (Kaplan-Meier test); factors predictive of these end points were determined by multivariate analysis.

RESULTS

The mean age at operation was 73 years. A total of 76% of patients were male; 11% had renal insufficiency (creatinine > or =1.5 mg/dL), and 13% had chronic obstructive pulmonary disease. The aortic cross-clamp position was suprarenal in 135 (25%) patients, and 284 (53%) of patients had bifurcated grafts placed. Operative mortality (30 days) was 3%, and the median length of hospital stay was 7 days. Postoperative complications occurred in 68 (13%) patients. Predictors of postoperative complications included a history of myocardial infarction (hazard ratio [HR], 2.0; P = .01) and renal insufficiency (HR, 2.5; P = .02). The mean follow-up for all patients was 87 months. Actuarial survival was 70.7% +/- 2% and 44.3% +/- 2.4% at 5 and 10 years, respectively. Negative predictors of long-term survival included advanced age (HR, 1.1; P < .001), history of myocardial infarction (HR, 1.37; P = .02), and renal insufficiency (HR, 1.5; P = .04). Freedom from graft-related reintervention was 98.2% +/- 0.8% and 94.3% +/- 3.4% at 5 and 10 years, respectively. There were 13 late graft-related complications in 11 (2%) patients (mean follow-up, 7.2 years). Findings included seven anastomotic pseudoaneurysms (five were repaired), four graft limb occlusions, and two graft infections. Aneurysms were identified in noncontiguous arterial segments in 68 (45%) of 152 patients, most of which involved the iliac arteries and required no treatment because of small size. Late aortic aneurysms proximal to the repair were identified in 24% of patients, and 29 (19%) patients had multiple late synchronous aneurysms.

CONCLUSIONS

Open repair remains a safe and durable option for the management of abdominal aortic aneurysms, with an excellent associated 10-year survival in patients who undergo operation at 75 years of age or younger. In addition, the freedom from graft-related reintervention is superior to that of EVAR. Finally, continued surveillance after open repair is appropriate and should be directed toward the detection of other aneurysms.

Secondary Interventions and Mortality Following Endovascular Aortic Aneurysm Repair: Device-specific Results from the UK EVAR Trials

OBJECTIVES

To compare secondary intervention rate, aneurysm-related mortality and all-cause mortality for patients receiving elective endovascular aneurysm repair (EVAR) for large abdominal aortic aneurysms with different commercially available endografts.

DESIGN, MATERIALS & METHODS

In the EVAR 1 and 2 multi-centre trials, the principal endografts used were Zenith and Talent and these are compared in 505 patients from EVAR 1 and 143 patients from EVAR 2 followed-up for an average of 3.8 years until 31st December 2005. Outcomes were analysed by Cox proportional hazards regression, with adjustments for potential confounding risk factors and centre. Gore/Excluder graft outcomes also are reported.

RESULTS

Across the two trials the secondary intervention rates were 7.0 and 9.4 per 100 patient years for Zenith and Talent grafts respectively, adjusted hazard ratio 0.77 [95%CI 0.52-1.12]. Aneurysm-related mortality was 1.2 and 1.4 per 100 patient years for Zenith and Talent grafts respectively, adjusted hazard ratio 0.90 [95%CI 0.37-2.19]. All-cause mortality was 8.5 and 10.3 per 100 patient years for Zenith and Talent grafts respectively, adjusted hazard ratio 0.81 [95%CI 0.58-1.14]. The direction of all results was similar when the two trials were analysed separately.

CONCLUSION

There was no significant difference in the performance of the two endografts but the direction of results was slightly in favour of patients with Zenith (versus Talent) endografts.

Endovascular treatment of aortic aneurysms: techniques and clinical update

Open repair of abdominal and thoracic aortic aneurysms continues to be associated with considerable morbidity and mortality. Endovascular repair of abdominal and thoracic aortic aneurysms has evolved over the past few years and has significantly reduced the morbidity of aortic aneurysm repair compared with the standard open surgical procedures. Several devices have been approved for clinical use for this purpose. This has allowed the treatment of patients who are otherwise at high risk for open repair. This review paper aims to (1) describe the general principles of use for endovascular devices and review the radiographic features and clinical trials for the devices in current use, (2) present the results of the clinical trials that led to the approval and marketing of the current devices, and (3) review new techniques and approaches for the treatment of aortic aneurysms.

Who should we operate on and how do we decide: predicting rupture and survival in patients with aortic aneurysm

The decision to operate on a patient with an aortic aneurysm is based on the risk of aneurysm rupture versus the risk of aneurysm repair, within the context of the patient's overall life expectancy. Risk of rupture is still primarily based on the maximum aneurysm diameter, with some allowances made for factors that modify rupture risk, such as gender and current smoking. Newer methods for determining rupture risk, such as aneurysm-wall stress analysis, appear promising, but are not yet broadly available. Until then, diameter-based prediction rules for rupture risk will "fail" 10% to 25% of patients with both small and large abdominal aortic aneurysms. With regard to predicting operative mortality and life expectancy after open or endovascular aneurysm repair, multiple risk-stratification algorithms have been created. The best of these algorithms are accurate in 75% to 80% of patients, meaning that they fail in 20% to 25% of cases. Prediction algorithms provide significant guidance, but cannot take the place of an experienced clinician at this point. Somehow, experienced surgeons are able to sift through a massive amount of information and properly select patients who are appropriate for surgery, with quite reasonable perioperative and long-term mortality rates.

Thoracic aortic stent-graft devices: problems, failure modes, and applicability

Optimal treatment strategies for pathologies of the descending thoracic aorta are still controversial. Open surgery is complex, while endovascular devices allow nonsurgical access to the thoracic aorta. Endografts can be inserted via a peripheral artery while maintaining aortic blood flow without any need for clamping. Both short- and mid-term outcomes after endografting thoracic aneurysm and type B aortic dissection are encouraging, with significantly lower morbidity and early mortality compared with open surgery. However, despite emerging popularity and growing interest as an alternative to surgery, endograft design and manufacturing have not kept pace with growing clinical ambition. Major challenges associated with endovascular procedures using the current generation of endografts range from the relative rigidity and size of the delivery system to the failure of thoracic endografts to conform snugly to the anatomy of the aortic arch. Nonconformity of grafts may lead to graft instability, endoleak, and procedural failure. Current delivery systems are potentially traumatizing and, at times, too inflexible to track through tortuous, calcified vessels, and often require surgical exposure of the access vessel. Although efforts have been made by the industry to improve conformability and fixation in the aortic arch, given the spiraling movement of the thoracic aorta with each ventricular contraction, much work needs to be done on miniaturization and creation of disease-specific devices. The aim of this work is to give an overview on thoracic aortic stent-graft devices with focus on problems, failure modes and potential improvements.

Applicability of Glasgow Aneurysm Score and Hardman Index to elective endovascular abdominal aortic aneurysm repair

OBJECTIVE

This retrospective study aimed to explore the role of Glasgow Aneurysm Score (GAS) and Hardman Index (HI) in predicting outcome after elective endovascular aneurysm repair (EVAR).

METHODS

All 71 patients who underwent elective EVAR in a single centre over 9 years were reviewed. Clinical data were used to classify patients into the three standard GAS tertiles and to score patients according to the HI.

RESULTS

Fifty-one patients scored > or = 77 according to GAS. Actual and predicted mortality in this group were 3.9% and 9.3%. Seventeen patients scored between 69 and 77 with actual and predicted mortality of 0% and 4.1%. Three patients scored less than 69 with actual and predicted mortality of 0% and 2.4%. Ten patients scored > or = 3 on the HI with actual and predicted mortality of 10% and 100%, respectively. Twenty-four patients scored 2 with actual and predicted mortality of 4.2% and 55%. Twenty-seven patients scored 1 with actual and predicted mortality of 0% and 28%, respectively. Ten patients scored 0 with actual and predicted mortality of 0% and 16%, respectively. The chi(2) test showed extremely significant p value of 0.0001 in case of HI, and p value of 0.0800 for GAS, slightly less significant, probably due to the small sample size.

CONCLUSION

Contrary to their role in ruptured and open aortic aneurysm repair, GAS and HI overestimate both mortality and morbidity following EVAR and are poor predictors of outcome.

Endovascular Repair of Infrarenal Abdominal Aortic Aneurysms in High-Risk-Surgical Patients

PURPOSE

Following the publication of a prospective randomized trial (EVAR2) that questioned the benefit of endovascular repair of abdominal aortic aneurysms (AAA) for high-surgical-risk patients, we evaluated our own initial and long-term results with endovascular AAA repair for this patient population.

MATERIAL AND METHODS

Between January 2000 and December 2005, 115 patients with an AAA managed by an aortic endograft were entered in a registry. Data concerning diagnosis, operative risk, treatment, and follow-up were analyzed on an intention-to-treat basis for all patients considered to be poor candidates for surgery. Patients with a ruptured AAA and those who were good surgical candidates were excluded from analysis. The main goal was evaluation of the operative mortality and the long-term survival of these patients. Secondary goals were determination of the frequency of secondary operations, the outcome of the aneurysm sac, and primary and secondary patency rates after aortic endograft placement.

RESULTS

A total of 92 high-surgical-risk patients treated by an endograft were entered in this study. Sixty-seven patients (73%) were classed ASA III and 18 (20%) were ASA IV (20%). Mean aneurysm diameter was 58 mm+/-9 mm. The technical success rate was 99%. Operative mortality was 4.3% (4 cases). Four patients required re-intervention during the mean follow-up of 18 months. The survival rate at 3 yr was 85%. One type I endoleak (1%) and 9 type II endoleaks (9.7%) occurred during the follow-up period. Primary and secondary patency rates at 3 yr were respectively 96% and 100%.

CONCLUSION

Our initial and long-term results with endograft repair of AAA in high-surgical-risk patients were satisfactory. These results appear to justify endovascular repair for this patient population.

Persistent type 2 endoleak after endovascular repair of abdominal aortic aneurysm is associated with adverse late outcomes

OBJECTIVE

Type 2 endoleak occurs in up to 20% of patients after endovascular aneurysm repair (EVAR), but its long-term significance is debated. We reviewed our experience to evaluate late outcomes associated with type 2 endoleak.

METHODS

During the interval January 1994 to December 2005, 873 patients underwent EVAR. Computed tomography (CT) scan assessment was performed < or =1 month of the operation and at least annually thereafter. Sequential 6-month CT scan follow-up was adopted for those patients with persistent type 2 endoleaks, and reintervention was limited to those with sac enlargement >5 mm. Study end points included overall survival, aneurysm sac growth, reintervention rate, conversion to open repair, and abdominal aortic aneurysm (AAA) rupture. Preoperative variables and anatomic factors potentially associated with these endpoints were assessed using multivariate analysis.

RESULTS

We identified 164 (18.9%) patients with early (at the first follow-up CT scan) type 2 endoleaks. Mean follow-up was 32.6 months. In 131 (79.9%) early type 2 endoleaks, complete and permanent leak resolution occurred < or =6 months. Endoleaks persisted in 33 patients (3.8% of total patients; 20.1% of early type 2 endoleaks) for >6 months. Transient type 2 endoleak (those that resolved < or =6 months of EVAR) was not associated with adverse late outcomes. In contrast, persistent endoleak was associated with several adverse outcomes. AAA-related death was not significantly different between patients with and without a type 2 endoleak (P = .78). When evaluating patients with no early endoleak vs persistent endoleak, freedom from sac expansion at 1, 3, and 5 years was 99.2%, 97.6%, and 94.9% (no leak) vs 88.1%, 48.0%, and 28.0% (persistent) (P < .001). Patients with persistent endoleak were at increased risk for aneurysm sac growth vs patients without endoleak (odds ratio [OR], 25.9; 95% confidence interval [CI] 11.8 to 57.4; P < .001). Patients with a persistent endoleak also had a significantly increased rate of reintervention (OR, 19.0; 95% CI, 8.0 to 44.7); P < .001). Finally, aneurysm rupture occurred in 4 patients with type 2 endoleaks. Freedom from rupture at 1, 3, and 5 years for patients with a persistent type 2 endoleak was 96.8%, 96.8%, and 91.1% vs 99.8%, 98.5%, and 97.4% for patients without a type 2 endoleak. Multivariate analysis demonstrated persistent type 2 endoleak to be a significant predictor of aneurysm rupture (P = .03).

CONCLUSIONS

Persistent type 2 endoleak is associated with an increased incidence of adverse outcomes, including aneurysm sac growth, the need for conversion to open repair, reintervention rate, and rupture. These data suggest that patients with persistent type 2 endoleak (>6 months) should be considered for more frequent follow-up or a more aggressive approach to reintervention.

Epidemiology and Long-Term Prognostic Factors in Acute Type B Aortic Dissection

The epidemiological data and reports on long-term predictors of mortality after medically or endovascularly and medically treated patients with acute type B aortic dissection (AD) are scarce. Patients with type B AD between 2000 and 2004 were identified through the inpatient endovascular or autopsy registry at Malmö-Lund University Hospital, Sweden. Seventy-two patients had acute type B AD, of whom eight were found at autopsy. Shock due to ruptured type B AD was associated with in-hospital mortality (P = 0.006) in the 64 eligible patients. Renal insufficiency (odds ratio [OR] = 4.7, 95% confidence interval [CI] 1.1-19.4) and coexistent aortic disease (OR = 4.1, 95% CI 1.0-16.9) remained as independent predictors for long-term mortality after multivariate logistic regression analysis. Endovascular intervention (n = 32) was associated with neither short- nor long-term mortality. The estimated overall incidence of acute type B AD was 2.1/100,000 person-years, and the highest incidence rates were found in men aged 65-74 years (14.6/100,000 person-years) and women aged 75-84 years (19.0/100,000 person-years). Survival in patients with complicated acute type B AD managed with the endovascular technique was the same as in uncomplicated medically treated patients. Renal insufficiency and coexistent aortic disease were strong predictors for long-term mortality.

Aneurysmen und Dissektionen der thorakalen und abdominellen Aorta

One to four per cent of all deaths in patients over 65 are caused by aneurysmatic diseases of the abdominal or thoracic aorta. For elective surgery in abdominal aneurysms, open surgery and endovascular treatment both demonstrate brilliant overall results. In the thoracic aorta, new endovascular procedures have led to considerable reductions of postoperative morbidity and mortality. Nevertheless, in view of the endovascular procedure's high cost and the still unclear long-term behaviour of the stent device, a second opinion from a specialised centre is an absolute necessity.

Endovascular Graft Limb Occlusion After an Anterior Resection for Rectal Cancer: Report of a Case

An endovascular aneurysm repair has become an important therapeutic option for the management of patients with aortic aneurysms. Early advantages of the endovascular technique have been well documented. Patients with aortic aneurysms undergoing these procedures are usually elderly, which increases the likelihood of comorbidities. With the increased use of vascular devices, potential complications such as graft limb occlusion need to be widely understood, so they can be recognized and treated early. We recently treated an 85-year-old man with acute endovascular graft limb occlusion after an elective anterior resection for rectal cancer, and we discuss some factors that may have contributed to this complication.

Infrarenal Abdominal Aortic Aneurysm Repair: Time-trends during a 20-year Period

BACKGROUND

The goal of the present study was to investigate the number of operations for abdominal aortic aneurysm (AAA) including time-trends in treatment during a 20-year period. Operating time and anesthesia time were also studied.

METHOD

During the period 1983-2002, a total of 1,041 patients with AAA were treated with open surgery (905) or EVAR (136). Number of operations, type of graft, anesthesia time, and operating time were the variables investigated. Data were collected retrospectively from the patients' medical records.

RESULTS

There was an increase in the number of operations both for ruptured and non-ruptured AAA in men during the study period. Among women, an increase was observed only for ruptured aneurysm. Operating time and anesthesia time increased significantly during the 20-year period. The number of patients treated by EVAR increased significantly, beginning in 1995.

CONCLUSIONS

In conclusion, there has been an increase in the number of AAA operations, and the proportion of patients treated with EVAR is increasing. Furthermore, we found an increase in both anesthesia time and operating time. These trends may be important for allocation of resources needed for the treatment of patients with AAA.

Objective scoring systems of medical risk: A clinical tool for selecting patients for open or endovascular abdominal aortic aneurysm repair

BACKGROUND

Objective scoring systems have been developed for risk stratification of open infrarenal aneurysm repair. To date, none have been applied for the selection of patients who would most benefit from either an open or an endovascular approach. This study assessed the utility of comorbidity-based objective scoring systems for defining subgroups of patients who might most benefit from open or endovascular aneurysm repair.

METHODS

A retrospective database review was performed for the period January 1999 to December 2004 to identify patients who had undergone elective open aneurysm repair (open repair) or elective endovascular aneurysm repair (EVAR). Validation of the Glasgow Aneurysm Score (GAS), the Modified Leiden Score (M-LS), and the Modified Comorbidity Severity Score (M-CSS) was performed for perioperative mortality risk in the open repair group. GAS, M-LS, and M-CSS were then calculated for the EVAR group. Differences in open repair vs EVAR mortalities were evaluated.

RESULTS

During the time period, 558 patients underwent open repair and 304 underwent EVAR. Overall mortality was 4.7% for open repair patients and 2.0% for EVAR. All three scoring systems were validated to our open repair data set (C statistic: GAS, 0.72; M-LS, 0.71; M-CSS, 0.74). A score was calculated for each system that separated patients into groups of either low or high risk of death for open repair. This score (cut point) was 76.5 for the GAS, 5.2 for the M-LS, and 8 for the M-CSS. Analysis of the EVAR population revealed that patients at low medical risk for open repair did not derive statistically significant mortality benefit with EVAR; however, patients at high medical risk for open repair derived significant benefit from EVAR (GAS>76.5 mortality: open repair, 7.8%; EVAR, 1.9% [P<.01]; M-LS mortality: open repair, 8.1%; EVAR, 2.5% [P<.01]; and M-CSS mortality: open repair, 10.3%; EVAR, 3.4% [P<.025]). Despite a very small number of deaths (n=6), receiver operator curve analysis identified M-LS and M-CSS as having some predictive ability for mortality risk with EVAR (C statistic: M-LS, 0.70; M-CSS, 0.69).

CONCLUSION

Three validated objective scoring systems can be used to categorize patients into two groups of medical risk: one that has excellent outcome with open repair and derives no early mortality benefit from EVAR, and another that has significant mortality with open repair and derives important benefit with EVAR.

The Current Status of AAA Stent Grafting

It is now 16 years since the endovascular treatment of abdominal aortic aneurysm (AAA) was first described. It is probably true to say that, with current device technology, > 50% of all patients with an infrarenal aneurysm can be treated with an endograft. Endografting has become an important tool in the treatment of AAA. There are many reasons for this success. Rapid technical development followed the initial "homemade" devices, allowing easy accurate insertion. In early cohort series it was always the case that the operative mortality of endografting in AAA was lower than surgical treatment. In addition, postoperative management was easier and hospital stay was shorter after an endograft. No evidence indicated that quality of life improved after the perioperative period, however, and it was unclear whether the reduction in intensive hospital care requirement justified the considerable extra costs for an endovascular device. Despite these shortcomings, early widespread public awareness pushed endograft treatment forward. Patients started to ask for this new treatment option. But long-term outcome data then, and to some extent today, are still lacking.

Patient fitness and survival after abdominal aortic aneurysm repair in patients from the UK EVAR trials

Background

The aim was to use a validated fitness score to determine whether fitter patients with a large abdominal aortic aneurysm (AAA) benefited from having open rather than endovascular repair.

Methods

The Customized Probability Index (CPI) was applied to patients in the Endovascular Aneurysm Repair (EVAR) I and II trials. Interaction tests between CPI and randomized group assessed the effect of fitness and type of AAA repair on elective 30-day mortality and 4-year survival.

Results

The mean(s.d.) CPI scores were 3·6(9·3) for 1252 EVAR I patients and 10·0(11·3) for 404 EVAR II patients (range − 25 to + 43) (P &lt; 0·001). The fitness of EVAR I patients was classified as good (579 patients, mean CPI − 4·2), moderate (331 patients, mean CPI 5·7) or poor (338 patients, mean CPI 15·1). Only in the good fitness group did 30-day mortality convincingly favour endovascular repair (odds ratio 0·24, P = 0·030), but overall the test of interaction was not significant (P = 0·363). For 4-year all-cause and aneurysm-related mortality, there was no benefit for either treatment across all fitness scores (P = 0·281 and P = 0·371 respectively).

Conclusion

The benefit of endovascular repair was most convincing in the fittest patients. There was no evidence that the fittest patients benefited more from open surgery.

Myocardial Damage in High-risk Patients Undergoing Elective Endovascular or Open Infrarenal Abdominal Aortic Aneurysm Repair

OBJECTIVE

Dobutamine stress echocardiography (DSE) provides an objective assessment of the presence and extent of coronary artery disease. Therefore we compared cardiac outcome in patients at high-cardiac risk undergoing open or endovascular repair of infrarenal AAA using preoperative DSE results.

METHODS

Consecutive patients with >or=3 cardiac risk factors (age >70 years, angina pectoris, myocardial infarction, heart failure, stroke, renal failure, and diabetes mellitus) undergoing infrarenal AAA repair were reviewed retrospectively. All underwent cardiac stress testing using DSE. Postoperatively data on troponin release and ECG were collected on day 1, 3, 7, before discharge, and on day 30. The main outcome measures were perioperative myocardial damage and myocardial infarction or cardiovascular death.

RESULTS

All 77 patients (39 endovascular, 38 open) had a history of cardiac disease. The number and type of cardiac risk factors were similar in both groups. Also DSE results were similar: 55 vs 56%, 24 vs 28%, and 21 vs 18% had no, limited, or extensive stress induced myocardial ischemia respectively. The incidence of perioperative myocardial damage (47% vs 13%, p=0.001) and the combination of myocardial infarction or cardiovascular death (13% vs 0%, p=0.02) was significantly lower in patients receiving endovascular repair.

CONCLUSION

In patients with similar high cardiac risk, endovascular repair of infrarenal aortic aneurysms is associated with a reduced incidence of perioperative myocardial damage.

Survival Benefit of Endovascular Descending Thoracic Aortic Repair for the High-Risk Patient

BACKGROUND

Despite acceptable results reported with endovascular thoracic aortic repair (TEVAR), recent studies have questioned the merit of repair in asymptomatic patients considered high risk for open surgery. In this group, advanced age or comorbid conditions may reduce life expectancy, thus limiting the benefit of elective aneurysmectomy. This study was conducted to determine whether elective TEVAR improves survival for this cohort.

METHODS

Forty-six asymptomatic patients with descending thoracic aortic disease were considered high risk for open surgery for reasons of age of 80 years or older (47.8%) or comorbid conditions (84.8%), and were subsequently evaluated for elective TEVAR. Of these, 21 underwent TEVAR, while another 25 patients were excluded from TEVAR on the basis of unfavorable anatomy or refused intervention.

RESULTS

The mean age of the cohort was 77.0 +/- 7.0 years (p = 0.9 between groups). Prevalent comorbid conditions were similar between groups, and included coronary artery disease (p = 1.0), chronic obstructive pulmonary disease (p = 1.0), and peripheral vascular disease (p = 0.23). Mean maximum aortic diameter was 6.0 +/- 1.4 cm (p = 0.54 between groups). Indications for intervention included fusiform aneurysm (65.2%) and pseudoaneurysm or penetrating ulcer (32.6%). No 30-day mortality was observed after TEVAR. All-cause mortality in the entire cohort was 50%. Median actual time to mortality was different between groups (control, 9.2 months versus TEVAR, 24.9 months; p = 0.01). Life-table analysis demonstrated improved survival for TEVAR at 24 months (p = 0.05).

CONCLUSIONS

Although the overall prognosis for the asymptomatic patient with descending thoracic aortic disease at high risk for open surgery is poor, elective endovascular repair improves survival and should be considered a therapeutic option in this setting.

Mid-term survival after abdominal aortic aneurysm surgery predicted by cardiopulmonary exercise testing

Background

Cardiopulmonary exercise (CPX) testing measures how efficiently subjects meet increased metabolic demand. This study aimed to determine whether preoperative CPX testing predicted postoperative survival following elective abdominal aortic aneurysm (AAA) repair.

Methods

Some 130 patients had CPX testing before elective open AAA repair. Additional preoperative, operative and postoperative variables were recorded prospectively. Median follow-up was 35 months. The correlation of variables with survival was assessed by single and multiple regression analyses.

Results

CPX testing identified 30 of 130 patients who had been unfit before surgery. Two years after surgery the Kaplan–Meier survival estimate was 55 per cent for the 30 unfit patients, compared with 97 per cent for the 100 fit patients. The absolute difference in survival between these two groups at 2 years was 42 (95 per cent confidence interval 18 to 65) per cent (P &lt; 0·001).

Conclusion

Preoperative CPX testing, combined with simple co-morbidity scoring, identified patients unlikely to survive in the mid-term, even after successful AAA repair.

A clinical randomized trial to evaluate the safety of a noninvasive approach in high-risk patients undergoing major vascular surgery: the DECREASE-V Pilot Study

OBJECTIVES

The purpose of this research was to perform a feasibility study of prophylactic coronary revascularization in patients with preoperative extensive stress-induced ischemia.

BACKGROUND

Prophylactic coronary revascularization in vascular surgery patients with coronary artery disease does not improve postoperative outcome. If a beneficial effect is to be expected, then at least those with extensive coronary artery disease should benefit from this strategy.

METHODS

One thousand eight hundred eighty patients were screened, and those with > or =3 risk factors underwent cardiac testing using dobutamine echocardiography (17-segment model) or stress nuclear imaging (6-wall model). Those with extensive stress-induced ischemia (> or =5 segments or > or =3 walls) were randomly assigned for additional revascularization. All received beta-blockers aiming at a heart rate of 60 to 65 beats/min, and antiplatelet therapy was continued during surgery. The end points were the composite of all-cause death or myocardial infarction at 30 days and during 1-year follow-up.

RESULTS

Of 430 high-risk patients, 101 (23%) showed extensive ischemia and were randomly assigned to revascularization (n = 49) or no revascularization. Coronary angiography showed 2-vessel disease in 12 (24%), 3-vessel disease in 33 (67%), and left main in 4 (8%). Two patients died after revascularization, but before operation, because of a ruptured aneurysm. Revascularization did not improve 30-day outcome; the incidence of the composite end point was 43% versus 33% (odds ratio 1.4, 95% confidence interval 0.7 to 2.8; p = 0.30). Also, no benefit during 1-year follow-up was observed after coronary revascularization (49% vs. 44%, odds ratio 1.2, 95% confidence interval 0.7 to 2.3; p = 0.48).

CONCLUSIONS

In this randomized pilot study, designed to obtain efficacy and safety estimates, preoperative coronary revascularization in high-risk patients was not associated with an improved outcome.

Cost-effectiveness of abdominal aortic aneurysm repair: A systematic review

Objectives: A systematic review of the cost-effectiveness of abdominal aortic aneurysm (AAA) repair was conducted. Although open surgery has been considered the gold standard for prevention of AAA rupture, emerging less-invasive endovascular treatments have led to increased interest in evaluating the cost and cost-effectiveness of treatment options.

Methods: A systematic review of studies published in MEDLINE between 1999 and 2005 reporting the cost and/or cost-effectiveness of endovascular and/or open surgical repair of nonruptured AAAs was conducted. Case series studies with less than fifty patients per treatment were excluded.

Results: Of twenty eligible articles, three were randomized controlled trials, twelve case series, four Markov models, and one systematic review. Regardless of time frame, all studies found that endovascular repair costs more than open surgery. Although the high cost of the endovascular prosthesis was partially offset by reduced intensive care, hospital length of stay, operating time, blood transfusions, and perioperative complications, hospital costs were still greater for endovascular than open surgical repair. For patients medically fit for open surgery, mid-term costs were greater for endovascular repair with no difference in overall survival or quality of life. For patients medically unfit for open surgery, endovascular repair costs more than no intervention with no difference in survival.

Conclusions: Although conclusions regarding the cost-effectiveness of AAA treatment options are time dependent and vary by institutional perspective, from a societal perspective, endovascular repair is not currently cost-effective for patients with large AAA regardless of medical fitness.

Endovascular abdominal aortic aneurysm repair

The operative mortality following conventional abdominal aortic aneurysm (AAA) repair has not fallen significantly over the past two decades. Since its inception in 1991, endovascular aneurysm repair (EVAR) has provided an alternative to open AAA repair and perhaps an opportunity to improve operative mortality. Two recent large randomised trials have demonstrated the short and medium term benefit of EVAR over open AAA repair, although data on the long term efficacy of the technique are still lacking. This review aimed at providing an overview of EVAR and a discussion of the potential benefits and current limitations of the technique.

Large infra-renal abdominal aortic aneurysms: endovascular vs. open repair--single centre experience

Endovascular aneurysm repair (EVAR) has become an established alternative to open repair (OR). We present a consecutive series of 486 elective patients with large infra-renal aortic abdominal aneurysm, comparing OR with EVAR. Prospective data collected during an 8-year period from January 1997 to October 2005 was reviewed. Statistical analysis performed using SPSS data editor with chi(2) tests and Mann-Whitney U-tests. There were 486 patients with 329 OR (293 males, 36 females) with median age of 72 years with median diameter 6.3 cm and 157 EVAR (148 males, 9 females) with median age 75 years with median diameter 6.1 cm. Mortality was 13 (4%) for OR and 5 (3.2%) for EVAR (three of whom were in the UK EVAR 2 trial). Blood loss was significantly less for EVAR 500 ml vs. 1500 ml for OR. Sixty-five (19.8%) patients with OR had significantly more peri-operative complications compared with 14 (8.9%) with EVAR. The length of stay in hospital was significantly less for EVAR. This non-randomised study shows that although EVAR does not have a statistically significantly lower mortality, it does have statistically significantly lower complication rates compared with OR. EVAR can be achieved with good primary success, but long-term follow-up is essential to assess durability.

Improved survival after introduction of an emergency endovascular therapy protocol for ruptured abdominal aortic aneurysms

BACKGROUND

The study was conducted to demonstrate improved survival (30-day mortality) after the introduction of an emergency endovascular therapy protocol for ruptured abdominal aortic aneurysms (rAAA). Numerous authors have successfully demonstrated reduced mortality in patients with rAAA using endovascular techniques. Comparison of endovascular aneurysm repair (EVAR) with open repair for rAAA may be misleading, however, because EVAR cannot be performed on all patients, and selection bias may explain the superior performance of any given surgical or endovascular strategy. We developed a model to predict mortality in patients before the introduction of EVAR (preprotocol population), applied this model to predict 30-day mortality among prospective patients (postprotocol population), and compared observed vs expected results.

METHODS

We assessed 126 patients with rAAA. Primary outcome was 30-day mortality. Potential confounding variables were age, sex, presurgical lowest recorded systolic blood pressure (SBP), and glomerular filtration rate (GFR). A logistic regression model incorporating significant confounders was used to evaluate changes in 30-day mortality for all patients with rAAA after introduction of the EVAR protocol. Separate logistic regressions were done to compare 30-day mortality for preprotocol vs patients receiving EVAR and preprotocol vs patients receiving postprotocol open repair. Cumulative sum (CUSUM) analysis was used to assess shifts in the performance of the rAAA program over time.

RESULTS

Significant confounders were SBP, absence of SBP, and GFR. Logistic regression found evidence of lower mortality after the protocol was introduced, 17.9% vs 30.0% (odds ratio [OR], 0.385; 95% confidence interval [CI], 0.141 to 0.981; P = .046). Comparison of all open repairs (preprotocol and postprotocol) and EVAR demonstrated decreased risk for EVAR of 5.0% vs 28.3% (OR, 0.109; 95% CI, 0.013 to 0.906; P = .0084). Unstable patients (SBP <or=80) showed a trend towards improved survival with EVAR relative to open repair (14.3% vs 56.0%, P = .061). Comparison of preprotocol surgery with open repair after the introduction of the protocol found no evidence of a difference between mortality rates for the open procedures-30.0% (preprotocol) vs 25.0% (postprotocol; OR, 0.688; 95% CI, 0.335 to 1.415, P = .3031)-demonstrating that the improved performance observed with CUSUM analysis was related to the introduction of the EVAR protocol.

CONCLUSION

Our predictive model using "weighted" CUSUM analysis (a measure of performance over time) demonstrated that a predefined strategy of management of rAAA that includes EVAR is associated with improved (P < .05) mortality. Unstable patients with rAAA may be particularly benefited by EVAR and should not be excluded from repair. Appropriate patients with rAAA who are undergoing treatment in experienced vascular centers should be offered EVAR as the treatment of choice.

Predictors for Outcome after Open and Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

OBJECTIVES

The aims of the present study were to analyze patient- and management-related predictors for outcome after open (OR) and endovascular repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA).

DESIGN

Retrospective study.

MATERIALS

The in-hospital registry of Malmö University Hospital identified 162 patients operated on due to rAAA between 2000 and 2004.

METHODS

Patient- and management-related predictors for outcome were analysed.

RESULTS

Preoperative CT in 39 out of 62 circulatory unstable patients was not associated with increased mortality (p=0.60). There was a significant increase in repairs performed by EVAR during the study period (p<0.001), and in 2004 EVAR exceeded the annual rate of OR. Patients in the EVAR group were older (p=0.025), whereas patients in the OR group more often suffered from unconsciousness after presentation (p=0.004). Age, unconsciousness after presentation and haemoglobin were significantly associated with in-hospital mortality when tested in a multivariate logistic regression model (p=0.002, p=0.003 and p<0.001, respectively). The in-hospital mortality for patients undergoing OR and EVAR was 45% (48/106) and 34% (19/56), respectively (p=0.16). Diagnosis of abdominal compartment syndrome (p=0.005) and intestinal infarction (p=0.002) was associated with poor survival.

CONCLUSIONS

Patient-related factors such as age, loss of consciousness and haemoglobin predicts outcome in a population where both emergency OR and EVAR for the treatment of rAAA is feasible.

The outcome of endovascular repair of small abdominal aortic aneurysms

OBJECTIVE

To assess the outcome of endovascular repair (EVAR) of small abdominal aortic aneurysms (AAA, <or=5.5 mm maximum diameter) in Australia.

SUMMARY BACKGROUND DATA

Randomized trials have suggested that small AAAs should not be treated by open surgery. EVAR is associated with less perioperative mortality than open surgery for large AAAs. We assessed the outcome of EVAR of small AAAs as part of a national audit.

METHODS

ASERNIP-S carried out a prospective audit of EVAR performed between November 1999 and May 2001 in Australia. A total of 478 of the 961 patients entered underwent treatment of a small AAA. Data were collected regarding preoperative characteristics, procedural outcome, and intermediate success. Median follow-up was 3.2 years. Data were analyzed using Kaplan-Meier and Cox proportional hazard analyses.

RESULTS

The 30-day mortality and technical success rates were 1.1% and 98%, respectively. Postoperative complications occurred in 29%. Survival was 84% and 52% at 3 and 5 years, respectively. Primary, assisted primary, and secondary clinical success rates were 72%, 79%, and 82%, respectively, at 3 years. Reintervention rate was 11% at 3 years; however, 15% of patients continued to have significant aortic sac enlargement. Survival was reduced in patients considered unfit for general anesthesia (odds ratio = 2.6; 95% confidence interval, 1.4-4.8, P = 0.002) or those who had elevated preoperative serum creatinine (odds ratio = 2.0; 95% confidence interval, 1.3-3.0, P = 0.001).

CONCLUSIONS

EVAR can be carried with good perioperative outcome in patients with small AAA; however, intermediate success is hampered by the need for reintervention and continued aortic sac enlargement. At present, widespread treatment of small AAAs by EVAR would appear inappropriate.

Should usual criteria for intervention in abdominal aortic aneurysms be "downsized," considering reported risk reduction with endovascular repair?

Two randomized trials have demonstrated the safety of waiting until abdominal aortic aneurysm (AAA) diameter reaches 5.5 cm for repair in most patients. Other recent randomized trials have demonstrated lower perioperative mortality and morbidity with endovascular aneurysm repair (EVAR) compared to open surgery. Therefore, it is logical to assume that endovascular repair may change the appropriate threshold for intervention. However, endovascular repair is not as durable as open surgery and is associated with ongoing risks of rupture and reintervention. Decision analysis based on data available in 1998 showed that endovascular repair should not change the threshold for intervention. Since that time retrospective data have emerged to suggest that outcomes with endovascular repair are improved in smaller AAAs, although this may simply represent selection bias and the natural history of small AAAs. Randomized trials are appropriate to determine whether improved endovascular outcomes in small AAAs reduce late rupture and reintervention enough to justify early intervention in patients with appropriate anatomy. In the absence of data from these trials, the threshold for intervention should not be changed.

Performance of endovascular aortic aneurysm repair in high-risk patients: Results from the Veterans Affairs National Surgical Quality Improvement Program

OBJECTIVE

Recent results after endovascular abdominal aortic aneurysm repair (EVAR) have brought into question its value in patients deemed at high-risk for surgical intervention. The Department of Veteran Affairs (VA) National Surgical Quality Improvement Program (NSQIP) is the largest prospectively collected and validated United States surgical database representing current clinical practice. The purpose of our study was to evaluate outcomes after elective EVAR performed in high-risk veterans.

METHODS

Using NSQIP data from 123 participating VA hospitals, we retrospectively evaluated patients who underwent elective aneurysm repair from May 2001 to December 2004. High-risk criteria were used to identify a cohort for analysis (EVAR, n = 788; open, n = 1580). High-risk criteria analyzed included age > or =60 years, American Society of Anesthesiology (ASA) classification 3 or 4, and the comorbidity variables of history of cardiac, respiratory, or hepatic disease, cardiac revascularization, renal insufficiency, and low serum albumin level. Our primary end points were 30-day and 1-year all-cause mortality, and we evaluated a secondary end point of perioperative complications. Statistical analysis included univariate analysis and multivariate modeling.

RESULTS

Veterans who were classified as high-risk underwent elective EVAR with significantly lower 30-day (3.4% vs 5.2%, P = .047) and 1-year all-cause mortality (9.5% vs 12.4%, P = .038) than patients having open repair. EVAR was associated with a decrease in 30-day postoperative mortality (adjusted odds ratio [OR], 0.65; 95% confidence interval [CI], 0.42 to 1.03; P = .067) as well as 1-year mortality (adjusted OR, 0.68; 95% CI, 0.51 to 0.91; P = .0094) despite the presence of severe comorbid conditions. The risk of perioperative complications was significantly lower after EVAR (16.2% vs 31.0%; P < .0001; adjusted OR, 0.41; 95% CI, 0.33 to 0.52; P < .0001). A subset analysis of higher-risk patients (ASA 4 and the above comorbidity variables) still demonstrated an acceptable 30-day mortality rate.

CONCLUSION

In veterans deemed high-risk for surgical therapy, outcomes after elective EVAR are excellent, and the procedure is relatively safe in this special patient population. Our retrospective data demonstrate that patients with considerable medical comorbidities and infrarenal abdominal aortic aneurysms benefit from and should be considered for primary EVAR.

Systematic Review and Meta-analysis of 12 Years of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (ER) of abdominal aortic aneurysm (AAA) is a new technique, and reported rates of endoleak, conversion to open repair, rupture and mortality vary widely. The aim of this study was to estimate these rates from the published data, and examine how this has changed as more patients have undergone ER.

METHODS

A systematic review and meta-analysis of publications identified through searches of the electronic databases EMBASE and Medline. All publications quoting endoleak, conversion to open repair, rupture and mortality rates for a series of patients undergoing ER were included.

RESULTS

163 studies pertaining to 28,862 patients undergoing ER were identified as relevant for the review and meta-analysis. The pooled estimate for operative mortality was 3.3% (95% confidence interval 2.9 to 3.6%). The pooled estimate for type 1 endoleaks was 10.5% (95% confidence interval 9.0 to 12.1%), with an annual rate of 8.4% (95% confidence interval 5.7% to 12.2%). The pooled estimate of type 2,3 and 4 endoleaks was 13.7% (95% confidence interval 12.3 to 15.3%), with an annual rate of 10.2% (95% confidence interval 7.4% to 14.1%). The pooled estimate for primary conversion to open repair was 3.8% (95% confidence interval 3.2 to 4.4%), and for secondary conversion to open repair 3.4% (95% confidence interval 2.8 to 4.2%). The pooled estimate for post-operative rupture was 1.3% (95% confidence interval 1.1 to 1.7%), with an annual rupture rate of 0.6% (95% confidence interval 0.5% to 0.8%). Multivariate meta-regression analysis showed that rates of operative mortality, post-operative rupture and total number of endoleaks all fell significantly (p<0.05) over time.

CONCLUSIONS

This study demonstrates a low mortality and a gradual reduction in vascular morbidity and mortality associated with endovascular repair since it was first introduced.

Biomechanics of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a condition whereby the terminal aorta permanently dilates to dangerous proportions, risking rupture. The biomechanics of AAA has been studied with great interest since aneurysm rupture is a mechanical failure of the degenerated aortic wall and is a significant cause of death in developed countries. In this review article, the importance of considering the biomechanics of AAA is discussed, and then the history and the state-of-the-art of this field is reviewed--including investigations into the biomechanical behavior of AAA tissues, modeling AAA wall stress and factors which influence it, and the potential clinical utility of these estimates in predicting AAA rupture.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (the pathological enlargement of the aorta) can develop in both men and women as they grow older. It is most commonly seen in men over the age of 65 years. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, a fatal event unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. A newer minimally invasive technique, endovascular repair, has been shown to reduce early morbidity and mortality, as compared to conventional open surgery, for planned AAA repair. Emergency endovascular repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in selected patients. However, it is not yet known if eEVAR will lead to significant improvements in outcomes for these patients or indeed if it can replace conventional open repair as the preferred treatment for this lethal condition.

OBJECTIVES

To compare the advantages and disadvantages of eEVAR in comparison with conventional open surgical repair for the treatment of RAAA.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group searched their trials register (last searched October 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL) database (last searched Issue 4, 2006). We searched a number of electronic databases and handsearched relevant journals until March 2006 to identify studies for inclusion.

SELECTION CRITERIA

Randomised controlled trials in which patients with a confirmed ruptured abdominal aortic aneurysm were randomly allocated to eEVAR, or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Studies identified for potential inclusion were independently assessed for eligibility by at least two reviewers, with excluded studies further checked by the agreed arbitrators. As no randomised controlled trials were identified at present no tests of heterogeneity or sensitivity analysis were performed.

MAIN RESULTS

There were no randomised controlled trials identified at present comparing eEVAR with conventional open surgical repair for the treatment of RAAA.

AUTHORS' CONCLUSIONS

There is no high quality evidence to support the use of eEVAR in the treatment of RAAA. However, evidence from prospective controlled studies without randomisation, prospective studies, and retrospective case series suggest that eEVAR is feasible in selected patients, with outcomes comparable to best conventional open surgical repair for the treatment of RAAA . Furthermore, endovascular repair in selected patients may be associated with a trend towards reductions in blood loss, duration of intensive care treatment, and mortality.

Hybrid treatment for complex aortic problems combining surgery and stenting in the integrated operating theater

OBJECTIVES

Conventional surgical treatment of complex aortic pathologies involving several thoracoabdominal aortic segments necessitates extended incisions or subsequent surgeries, resulting in significant mortality and morbidity rates. The combination of surgery and simultaneous stenting in the operating theater may reduce the surgical trauma.

METHODS

A total of nine patients (62 +/- 10 years, range 44-70) underwent a combined surgical and endovascular treatment of thoracic or thoracoabdominal aortic aneurysms or chronic dissection. Five patients were treated with viscero-renal artery translocation followed by transfemoral stenting of the entire thoracoabdominal aorta. Two patients underwent debranching of the supraaortic vessels followed by immediate transfemoral stenting of the aortic arch, and two patients with a history of an ascending aortic aneurysm repair were treated with open surgical debranching of the supraaortic trunks and repair of the ascending aorta and aortic arch with elephant trunk technique. Preoperatively, magnetic resonance imaging was used to check supraaortic and intracranial vessels as well as the completeness of the Circle of Willisi prior to arch stenting and/or supraaortic vessel surgery. Cerebrospinal fluid drainage and induced mild hypertension have been used for one-step thoracoabdominal aortic stenting.

RESULTS

Thirty-day mortality rate and incidence of paraplegia was 0%. There was a single reversible perioperative stroke after aortic arch stenting. One patient required temporary renal replacement therapy using continuous arterio-venous hemofiltration. There was one early reoperation at the superior mesenteric artery after viscero-renal translocation. Four type I endoleaks occurred in three patients requiring two interventions. All patients have been discharged to home.

CONCLUSION

The innovative combination of simultaneous conventional surgery and stenting reduces the operative burden for patients with complex aortic pathologies involving several segments of the thoracic and thoracoabdominal aorta. Arch debranching and viscero-renal artery translocation may avoid the use of thoracoabdominal incisions, cardiopulmonary bypass techniques, deep hypothermia, and circulatory arrest.

Current trends in the management of small abdominal aortic aneurysms

Over the past decade, there have been revolutionary changes in the diagnosis and treatment of abdominal aortic aneurysms. Minimally invasive endovascular technologies have decreased length of stay and, more importantly, improved at least the early outcomes compared with conventional open surgical therapy. Several large, randomized, prospective trials have re-evaluated the optimal size to treat abdominal aortic aneurysms. The guidelines and conclusions from these studies, the UK Small Aneurysm Trial and The Veterans Affairs Administration aneurysm Detection And Management Trial recommend intervening on aortic aneurysms when they reach 5.5 cm in transverse diameter. However, these studies do not bear direct relevance to contemporary management of aneurysms with endovascular techniques. Clinical trials are currently underway to assess the optimal size for treating abdominal aortic aneurysms with endovascular stent grafts.

Pathology, natural history and treatment of abdominal aortic aneurysms

With increasing age of the population and improvement of diagnostic tools, the incidence of abdominal aortic aneurysms (AAA) has been rising steadily. Despite an improvement in operative and interventional treatment options, AAA is the cause of death in 1-3% of men over 65 years of age in industrial countries, mostly due to rupture [1]. Therefore, routine screening for AAA by ultrasonography has been postulated in the past: a 60 year old man with an abdominal aortic diameter of less than 3 cm has a life-time risk of developing AAA close to zero. However, routine screening has not been found to be cost effective. Despite of the results of two well-designed studies, the limits of AAA qualifying the patient for surgery or intervention in contrast to conservative treatment is still a matter of debate. The present review article summarizes the current knowledge of the pathology, incidence, risks, natural course as well as symptoms and current treatment strategies of AAA on the basis of the recent literature.

Contemporary management of the infra-renal abdominal aortic aneurysm

Abdominal aortic aneurysms (AAAs) principally affect men over 60 years of age. Aneurysms are usually asymptomatic and detected coincidentally or following the onset of symptoms. Elective repair of an AAA is considered when the diameter reaches 5.5cm or annual expansion exceeds 1 cm. Rupture represents a catastrophic event and carries an unacceptably high mortality. The advent of endovascular repair heralds an improvement in operative outcome for this disease process. In this review we provide an overview of the recent trials investigating the management of non-ruptured and ruptured aneurysms and the strategies that may be invoked to lower the mortality of this disease process

Review of Interventional Repair for Abdominal Aortic Aneurysm

Abdominal aortic aneurysm is associated with high mortality rate. For over 50 years, open surgical repair was the standard approach for large aneurysms. However, over the past decade, endovascular aneurysm repair (EVAR) has emerged as a viable alternative. EVAR is associated with lower operative and short-term morbidity and mortality and similar long-term survival (up to 4 years) compared with surgical repair. Endoleak remains a significant limitation associated with aneurysm expansion and reintervention. With newer, more versatile endograft designs, improvements in durability, and better surveillance techniques, the utilization of EVAR is likely to continue to expand.

From Innumeracy to Insight: The Uncertainty of Help versus Harm in Treatment of Asymptomatic Aortic Aneurysms

There is insufficient evidence that the surgical treatment of asymptomatic infrarenal aneurysms > 5.5 cm. is beneficial to patients. This is the result of serious complications of aneurysm surgery and the dearth of information from randomized trials. Based on evidence from the literature we defined scenarios and translated data into natural frequency trees to improve understanding of the uncertainty of help versus harm due to treatment of aneurysms. Our analysis shows that the majority of patients can expect little on longevity from surgery while they are at risk of dying from surgery or suffering from serious morbidity. We conclude that, as long as uncertainty persist, patients should be treated in hospitals that can show very low surgical mortality and major morbidity rates. To further resolve the problem of uncertainty randomized trials for larger aneurysms should be performed. Important issues to discuss are the lower and upper limits of the diameter of the aneurysms and the age and risk profiles of the patients to be included in such trials.