Amsterdam Acute Aneurysm Trial Collaborators. Amsterdam Acute Aneurysm Trial: Background, Design, and Methods

Strategy of endovascular versus open repair for patients with clinical diagnosis of ruptured abdominal aortic aneurysm: the IMPROVE RCT

BACKGROUND

Ruptured abdominal aortic aneurysm (AAA) is a common vascular emergency. The mortality from emergency endovascular repair may be much lower than the 40-50% reported for open surgery.

OBJECTIVE

To assess whether or not a strategy of endovascular repair compared with open repair reduces 30-day and mid-term mortality (including costs and cost-effectiveness) among patients with a suspected ruptured AAA.

DESIGN

Randomised controlled trial, with computer-generated telephone randomisation of participants in a 1 : 1 ratio, using variable block size, stratified by centre and without blinding.

SETTING

Vascular centres in the UK (n = 29) and Canada (n = 1) between 2009 and 2013.

PARTICIPANTS

A total of 613 eligible participants (480 men) with a ruptured aneurysm, clinically diagnosed at the trial centre.

INTERVENTIONS

A total of 316 participants were randomised to the endovascular strategy group (immediate computerised tomography followed by endovascular repair if anatomically suitable or, if not suitable, open repair) and 297 were randomised to the open repair group (computerised tomography optional).

MAIN OUTCOME MEASURES

The primary outcome measure was 30-day mortality, with 30-day reinterventions, costs and disposal as early secondary outcome measures. Later outcome measures included 1- and 3-year mortality, reinterventions, quality of life (QoL) and cost-effectiveness.

RESULTS

The 30-day mortality was 35.4% in the endovascular strategy group and 37.4% in the open repair group [odds ratio (OR) 0.92, 95% confidence interval (CI) 0.66 to 1.28; p = 0.62, and, after adjustment for age, sex and Hardman index, OR 0.94, 95% CI 0.67 to 1.33]. The endovascular strategy appeared to be more effective in women than in men (interaction test p = 0.02). More discharges in the endovascular strategy group (94%) than in the open repair group (77%) were directly to home (p < 0.001). Average 30-day costs were similar between groups, with the mean difference in costs being -£1186 (95% CI -£2997 to £625), favouring the endovascular strategy group. After 1 year, survival and reintervention rates were similar in the two groups, QoL (at both 3 and 12 months) was higher in the endovascular strategy group and the mean cost difference was -£2329 (95% CI -£5489 to £922). At 3 years, mortality was 48% and 56% in the endovascular strategy group and open repair group, respectively (OR 0.73, 95% CI 0.53 to 1.00; p = 0.053), with a stronger benefit for the endovascular strategy in the subgroup of 502 participants in whom repair was started for a proven rupture (OR 0.62, 95% CI 0.43 to 0.89; p = 0.009), whereas aneurysm-related reintervention rates were non-significantly higher in this group. At 3 years, considering all participants, there was a mean difference of 0.174 quality-adjusted life-years (QALYs) (95% CI 0.002 to 0.353 QALYs) and, among the endovascular strategy group, a cost difference of -£2605 (95% CI -£5966 to £702), leading to 88% of estimates in the cost-effectiveness plane being in the quadrant showing the endovascular strategy to be 'dominant'.

LIMITATIONS

Because of the pragmatic design of this trial, 33 participants in the endovascular strategy group and 26 in the open repair group breached randomisation allocation.

CONCLUSIONS

The endovascular strategy was not associated with a significant reduction in either 30-day mortality or cost but was associated with faster participant recovery. By 3 years, the endovascular strategy showed a survival and QALY gain and was highly likely to be cost-effective. Future research could include improving resuscitation for older persons with circulatory collapse, the impact of local anaesthesia and emergency consent procedures.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN48334791 and NCT00746122.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 31. See the NIHR Journals Library website for further project information.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) is a condition that can occur as a person ages. It is most commonly seen in men older than 65 years of age. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, which is fatal unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. Endovascular aneurysm repair (EVAR), a minimally invasive technique, has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. More recently emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in select patients; however, it is unclear if eEVAR will lead to significant improvements in outcomes for these patients or if indeed it can replace conventional open repair as the preferred treatment for this lethal condition. This is an update of the review first published in 2006.

OBJECTIVES

To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by comparing the effects of eEVAR and conventional open surgical repair on short-term mortality, major complication rates, aneurysm exclusion (specifically endoleaks in the eEVAR treatment group), and late complications.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register (last searched June 2016), CENTRAL (2016, Issue 5), and trials registries. We also checked reference lists of relevant publications.

SELECTION CRITERIA

Randomised controlled trials in which participants with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified for potential inclusion for eligibility. Two review authors also independently completed data extraction and quality assessment. Disagreements were resolved through discussion. We performed meta-analysis using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

We included four randomised controlled trials in this review. A total of 868 participants with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low, but we considered one study that performed randomisation in blocks by week and performed no allocation concealment and no blinding to be at high risk of selection bias. Another study did not adequately report random sequence generation, putting it at risk of selection bias, and two studies were underpowered. There was no clear evidence to support a difference between the two interventions for 30-day (or in-hospital) mortality (OR 0.88, 95% CI 0.66 to 1.16; moderate-quality evidence). There were a total of 44 endoleak events in 128 participants from three studies (low-quality evidence). Thirty-day complication outcomes (myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation, and respiratory failure) were reported in between one and three studies, therefore we were unable to draw a robust conclusion. We downgraded the quality of the evidence for myocardial infarction, renal complications, and respiratory failure due to imprecision, inconsistency, and risk of bias. Odds ratios for complications outcomes were OR 2.38 (95% CI 0.34 to 16.53; 139 participants; 2 studies; low-quality evidence) for myocardial infarction; OR 1.07 (95% CI 0.21 to 5.42; 255 participants; 3 studies; low-quality evidence) for renal complications; and OR 3.62 (95% CI 0.14 to 95.78; 32 participants; 1 study; low-quality evidence) for respiratory failure. There was low-quality evidence of a reduction in bowel ischaemia in the eEVAR treatment group, but very few events were reported (OR 0.37, 95% CI 0.14 to 0.94), and we downgraded the evidence due to imprecision and risk of bias. Six-month and one-year outcomes were evaluated in three studies, but only results from a single study could be used for each outcome, which showed no clear evidence of a difference between the interventions. We rated six-month mortality evidence as of moderate quality due to imprecision (OR 0.89, 95% CI 0.40 to 1.98; 116 participants).

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. We found from the data available moderate-quality evidence suggesting there is no difference in 30-day mortality between eEVAR and open repair. Not enough information was provided for complications for us to make a well-informed conclusion, although it is possible that eEVAR is associated with a reduction in bowel ischaemia. Long-term data were lacking for both survival and late complications. More high-quality randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Endovascular repair or open repair for ruptured abdominal aortic aneurysm: a Cochrane systematic review

OBJECTIVES

Emergency endovascular aneurysm repair (eEVAR) may improve outcomes for patients with ruptured abdominal aortic aneurysm (RAAA). The study aim was to compare the outcomes for eEVAR with conventional open surgical repair for the treatment of RAAA.

SETTING

A systematic review of relevant publications was performed. Randomised controlled trials (RCTs) comparing eEVAR with open surgical repair for RAAA were included.

PARTICIPANTS

3 RCTs were included, with a total of 761 patients with RAAA.

INTERVENTIONS

Meta-analysis was performed with fixed-effects models with ORs and 95% CIs for dichotomous data and mean differences with 95% CIs for continuous data.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was short-term mortality. Secondary outcome measures included aneurysm-specific and general complication rates, quality of life and economic analysis.

RESULTS

Overall risk of bias was low. There was no difference between the 2 interventions on 30-day (or in-hospital) mortality, OR 0.91 (95% CI 0.67 to 1.22; p=0.52). 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation and respiratory failure. Reporting was incomplete, and no robust conclusion was drawn. For complication outcomes that did include at least 2 studies in the meta-analysis, there was no clear evidence to support a difference between eEVAR and open repair. Longer term outcomes and cost per patient were evaluated in only a single study, thus precluding definite conclusions.

CONCLUSIONS

Outcomes between eEVAR and open repair, specifically 30-day mortality, are similar. However, further high-quality trials are required, as the paucity of data currently limits the conclusions.

Endovascular treatment for ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) (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 aneurysm repair (EVAR), has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. Emergency endovascular aneurysm 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 assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by the effect on short-term mortality, major complication rates, aneurysm exclusion, and late complications when compared with the effects in patients who have had conventional open repair of RAAA.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched February 2014) and CENTRAL (2014, Issue 2). Reference lists of relevant publications were also checked.

SELECTION CRITERIA

Randomised controlled trials in which patients with a clinically or radiologically diagnosed RAAA 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 review authors. Data extraction and quality assessment were also completed independently by two review authors. Disagreements were resolved through discussion. Meta-analysis was performed using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data.

MAIN RESULTS

Three randomised controlled trials were included in this review. A total of 761 patients with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low but one study did not adequately report random sequence generation, putting it at risk of selection bias, two studies did not report on outcomes identified in their protocol, indicating reporting bias, and one study was underpowered. There was no clear evidence to support a difference between the two interventions on 30-day (or in-hospital) mortality, OR of 0.91 (95% CI 0.67 to 1.22; P = 0.52). The 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, re-operation, amputation, and respiratory failure. Individual complication outcomes were reported in only one or two studies and therefore no robust conclusion can currently be drawn. For complication outcomes that did include at least two studies in the meta-analysis there was no clear evidence to support a difference between eEVAR and open repair. Six-month outcomes were evaluated in only a single study, which included mortality and re-operation, with no clear evidence of a difference between the interventions and no overall association. Cost per patient was only evaluated in a single study and therefore no overall associations can currently be derived.

AUTHORS' CONCLUSIONS

The conclusions of this review are currently limited by the paucity of data. From the data available there is no difference in the outcomes evaluated in this review between eEVAR and open repair, specifically 30-day mortality. Not enough information was provided for complications in order to make a well informed conclusion at this time. Long-term data are lacking for both survival and late complications. More high quality, randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed in order to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Endovascular Treatment versus Open Repair for Abdominal Aortic Aneurysms: The Influence of Fitness in Decision Making

Two methods of repair are currently available for an abdominal aortic aneurysm (AAA), open aneurysm repair and endovascular aneurysm repair (EVAR). The decision making depends on the balance of risks and benefits. The treating physician must take into account the patient's life expectancy, the patient's fitness, the anatomic suitability that makes endovascular repair possible, and finally the patient's preference. The patient's fitness is an important variable predicting the outcome of AAA surgical reconstruction. The hypothesis is that the impact of risk factors upon perioperative mortality might differ between patients undergoing open repair and endovascular repair. The purpose of this review article is to investigate whether fitter patients with a large AAA benefit more from having endovascular rather than open repair. According to the available data, there is emerging evidence that patients at high medical risk for open repair may benefit from EVAR while in low risk patients with suitable anatomy for EVAR, both techniques have similar effects. There is rising evidence that a patient with ruptured AAA would benefit more from an endovascular procedure if eligible, and thus fitness in such emergencies is not the first priority but anatomical suitability for EVAR.

Improved results in the management of ruptured abdominal aortic aneurysm may not be on the basis of endovascular aneurysm repair alone

Recent improvement in the survival of patients presenting with a ruptured abdominal aortic aneurysm (rAAA) has been credited to endovascular aneurysm repair (EVAR). We present our clinical series in the management of rAAA from 2007 to 2011. A total of 55 consecutive patient charts were reviewed. Thirty-eight patients underwent EVAR, 17 of the 55 patients did not have favorable anatomy for EVAR. Nine of the 17 patients underwent standard open repair. Eight patients underwent a 'hybrid repair' defined as suprarenal aortic endovascular balloon control followed by open repair. Overall 30-day mortality for all 55 patients was 22%. Mortality for the patients managed by endovascular aortic aneurysm repair was 26% compared with 22% with open repair. There were no deaths in the eight patients undergoing the hybrid repair. Endovascular balloon control of the aorta followed by open rAAA repair in patients who are not candidates for rEVAR has produced good results in our experience. Improved results being reported in the management of rAAA may not be on the basis of endovascular repair alone.

Semiautomatic sizing software in emergency endovascular aneurysm repair for ruptured abdominal aortic aneurysms

PURPOSE

In emergency endovascular repair (EVAR) of ruptured aneurysms of the aorta (rAAA), anatomical suitability must be determined. Semiautomatic three-dimensional assessment of the aortoiliac arteries has the potential to standardise measurements. This study assesses the fitness for purpose of such a semiautomatic approach for rAAA and determined interobserver agreement on suitability.

MATERIALS AND METHODS

Interobserver study with six trained observers (4 vascular surgeons, 2 radiologists) blindly assessing preoperative computed tomography angiography scans of 50 consecutive patients with rAAA. A central lumen line (CLL) was generated, and perpendicular diameters, length along the CLL, and EVAR suitability were determined using dedicated sizing software (3mensio; 3mensio Vascular; Bilthoven, The Netherlands). Success of generating a CLL, time of assessment, and interobserver agreement was determined.

RESULTS

In the majority of the patients (median 76 %, range 64-78 %), a CLL was semiautomatically generated. The median duration of CLL generation and performance measurements was 7.5 min (interquartile range 5.5-10.6). Agreement on suitability was moderate for the entire group (Fleiss' κ = 0.55, confidence interval 0.48-0.62) and ranged from moderate to good (Cohen's κ = 0.40-0.72) between observer pairs.

CONCLUSION

Assessing EVAR suitability of rAAA patients using dedicated sizing software is possible in the majority of patients. The measurements can be performed in a reasonable amount of time, and the agreement of suitability for EVAR in patients with rAAA is moderate. Improvements and additional research are necessary to replace the current axial measurement.

Ruptured abdominal aortic aneurysm: the state of play

BACKGROUND

Ruptured abdominal aortic aneurysm (rAAA) remains a challenging problem: 2,410 cases were treated in Germany in 2010. Ruptured abdominal aortic aneurysm should be suspected in patients over age 50 who complain of pain in the abdomen or back and in whom examination reveals a pulsatile abdominal mass. The incidence of hospitalization for rAAA is 12 per 100,000 persons over age 65 per year (statistics for Germany, 2010), and rAAA carries an overall mortality of 80%.

METHODS

The current state of knowledge of rAAA was surveyed in a selective review of pertinent literature retrieved by an electronic search in the PubMed, Web of Science, and Cochrane Library databases with the keywords "abdominal aortic aneurysm," "ruptured," "open repair," and "endovascular." Publications in English or German up to and including March 2012 were considered, among them the Clinical Practice Guidelines of the European Society for Vascular Surgery (1).

RESULTS AND CONCLUSIONS

Recent reports show that the treatment of rAAA is still fraught with high mortality and high perioperative morbidity. Improvement is needed. It would be advisable for the care of rAAA to be centralized in specialized vascular centers implementing defined treatment pathways. Systematic screening, too, would be beneficial. An increasing number of reports suggest that endovascular treatment with stent prostheses improves outcomes; more definitive evidence on this matter will come from prospective, randomized trials that are now in progress.

Early and mid-term results of a prospective observational study comparing emergency endovascular aneurysm repair with open surgery in both ruptured and unruptured acute abdominal aortic aneurysms

The aim of the paper is to prospectively describe early and mid-term outcomes for emergency endovascular aneurysm repair (eEVAR) versus open surgery in acute abdominal aortic aneurysms (aAAAs), both unruptured (symptomatic) and ruptured. We enrolled all consecutive patients treated for aAAA at our center between April 2002 and April 2008. The main outcome parameters were 30-day, 6- and 12-month mortality (all-cause and aneurysm-related). Two hundred forty patients were enrolled in the study. In the unruptured aAAA group ( n = 111), 47 (42%) underwent eEVAR. The 30-day, 6- and 12-month mortality rates were 6, 13 and 15% in the eEVAR group versus 11% (NS), 13% (NS) and 16% (NS) in the open group, respectively. In the ruptured aAAA group ( n = 129), 25 (19%) underwent eEVAR (mortality rates: 20, 28 and 36%, respectively) compared with 104 (81%) patients who underwent open surgery (mortality rates: 45% ( P = 0.021), 60% ( P = 0.004) and 63% ( P = 0.014), respectively). In conclusion, the present study showed a reduced 30-day, 6- and 12-month mortality of eEVAR compared with open surgery in all patients with aAAA, mainly due to a lower mortality in the ruptured aAAA group. Late aneurysm-related mortality occurred only in the eEVAR group.

Early Mortality Following Endovascular Versus Open Repair of Ruptured Abdominal Aortic Aneurysms

Purpose: To determine whether endovascular repair (EVAR) offers a survival advantage over open repair (OAR) with ruptured abdominal aortic aneurysms (RAAA). Methods: Retrospective analysis of RAAA patients treated between 2003 and 2008. Univariate and multivariate analyses were performed. Results: 167 patients presented with RAAA (OAR = 135, 80.8%, EVAR = 32, 19.2%). On univariate analysis, EVAR was associated with a decreased mortality relative to OAR, (15.6% vs 43.7%, P = .004). Patients who survived were younger (P < .0005), had a higher blood pressure (P < .0005), level of consciousness (P < .0005), and hemoglobin (P = .018), and a lower urea (P = .005) and international normalized ratio (INR; P = .001). On multivariate analysis, type of repair remained an independent predictor of 30-day mortality (OR: 0.121; 95% CI: 0.021-0.682, P = .017). Conclusion: Controlling for preoperative factors, EVAR is an independent predictor of lower 30 day mortality relative to open repair after RAAA. This supports the wider use of endovascular repair in all patients with RAAA.

The future of EVAR in the management of ruptured AAAs

Endovascular repair of ruptured abdominal aortic aneurysms is an evolving technique. Data from nonrandomized series suggest that it may be beneficial in selected patients. In the next few years, a number of large randomized clinical trials will clarify its role. Issues regarding anatomical suitability, techniques, perioperative care, and service provision need to be addressed in order to optimize outcomes.