Endovascular repair of abdominal aortic aneurysm--round two

Standardization of outcome measures in clinical trials of pharmacological treatment for abdominal aortic aneurysm

An abdominal aortic aneurysm (AAA) is a common aortic wall disease with an increased prevalence in the elderly population (4-8% for those aged >65 years). Many AAAs are slow growing and remain insidious. Current standard of care for patients with small AAAs (<49 mm) is surveillance, with interventional therapy (open surgical repair or endovascular aneurysm repair) recommended for large (>50-55 mm), rapidly growing (>10 mm/year) or symptomatic AAAs. Although open surgical repair or endovascular aneurysm repair are effective, significant short- and long-term postoperative morbidity and mortality occurs. Currently, there is no pharmacological treatment specific for AAA; the need for the development of targeted pharmacological therapies based on clinically relevant and feasible outcomes acceptable to the medical community, regulatory agencies and third-party payers is high. A consensus on such end points will be critical to accelerating the development of pharmacological agents to prevent formation, arrest the expansion and reduce the rupture risk of AAA.

Thirty-day mortality and late survival with reinterventions and readmissions after open and endovascular aortic aneurysm repair in Medicare beneficiaries

OBJECTIVES

Late survival is similar after open and endovascular abdominal aortic aneurysm (AAA) repair (EVAR), despite a perioperative benefit with EVAR. AAA-related reinterventions are more common after EVAR, whereas laparotomy-related reinterventions are more common after open repair. The effect of reinterventions on survival, however, is unknown. We therefore evaluated the rate of reinterventions and readmission after initial AAA repair, 30-day mortality, and the effect on long-term survival.

METHODS

We identified AAA-related and laparotomy-related reinterventions for propensity score-matched cohorts of 45,652 Medicare beneficiaries undergoing EVAR and open repair from 2001 to 2004. Follow-up was up to 6 years. Hospitalizations for ruptured AAA without repair and for bowel obstruction or ventral hernia without abdominal surgery were also recorded. Event rates were calculated per year and are presented through 6 years of follow-up as events per 100 person-years. Thirty-day mortality was calculated for each reintervention or readmission.

RESULTS

Through 6 years, overall reinterventions or readmissions were similar between repair methods but slightly more common after EVAR (7.6 vs 7.0/100 person-years; relative risk [RR], 1.1; P < .001). Overall 30-day mortality with any reintervention or readmission was 9.1%. EVAR patients had more ruptures (0.50 vs 0.09 [RR, 5.7; P < .001]), with a mortality of 28%, but these were uncommon. EVAR patients also had more AAA-related reinterventions through 6 years (3.7 vs 0.9 [RR, 4.0; P < .001]; mortality, 5.6%), most of which were minor endovascular reinterventions (2.4 vs 0.2 [RR, 11.4; P < .001]), with a 30-day mortality of 3.0%. However, minor open (0.8 vs 0.5 [RR, 1.4; P < .001]; mortality, 6.9%) and major reinterventions (0.4 vs 0.2 [RR, 2.4; P < .001]; mortality, 12.1%) were also more common after EVAR than open repair. Conversely, EVAR patients had fewer laparotomy-related reinterventions than open patients (1.4 vs 3.0 [RR, 0.5; P < .001]; mortality, 8.1%) and readmissions without surgery (2.0 vs 2.7 [RR, 0.7; P < .001]; mortality 10.9%). Overall, reinterventions or readmission accounted for 9.6% of all EVAR deaths and 7.6% of all open repair deaths in the follow-up period (P < .001).

CONCLUSIONS

Reintervention and readmission are slightly higher after EVAR. Survival is negatively affected by reintervention or readmission after EVAR and open surgery, which likely contributes to the erosion of the survival benefit of EVAR over time.

Long-term outcome of open or endovascular repair of abdominal aortic aneurysm

BACKGROUND

For patients with large abdominal aortic aneurysms, randomized trials have shown an initial overall survival benefit for elective endovascular repair over conventional open repair. This survival difference, however, was no longer significant in the second year after the procedure. Information regarding the comparative outcome more than 2 years after surgery is important for clinical decision making.

METHODS

We conducted a long-term, multicenter, randomized, controlled trial comparing open repair with endovascular repair in 351 patients with an abdominal aortic aneurysm of at least 5 cm in diameter who were considered suitable candidates for both techniques. The primary outcomes were rates of death from any cause and reintervention. Survival was calculated with the use of Kaplan-Meier methods on an intention-to-treat basis.

RESULTS

We randomly assigned 178 patients to undergo open repair and 173 to undergo endovascular repair. Six years after randomization, the cumulative survival rates were 69.9% for open repair and 68.9% for endovascular repair (difference, 1.0 percentage point; 95% confidence interval [CI], -8.8 to 10.8; P=0.97). The cumulative rates of freedom from secondary interventions were 81.9% for open repair and 70.4% for endovascular repair (difference, 11.5 percentage points; 95% CI, 2.0 to 21.0; P=0.03).

CONCLUSIONS

Six years after randomization, endovascular and open repair of abdominal aortic aneurysm resulted in similar rates of survival. The rate of secondary interventions was significantly higher for endovascular repair. (ClinicalTrials.gov number, NCT00421330.)

A single-institution experience with the AneuRx Stent Graft for endovascular repair of abdominal aortic aneurysm

We report our experience of endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) using the modular AneuRx Stent Graft System. We retrospectively reviewed the outcomes of 113 patients who underwent EVAR with the AneuRx system performed at our institution between October 1999 and August 2003. The mean age of this group was 72.5 years, with 71% (n = 80) over the age of 70 years and 95% (n = 107) males. Aneurysm diameter ranged 4.0-9.0 cm, with 33% (n = 37) >6.0 cm. The average duration of late follow-up was 32.6 +/- 24.8 months (median = 37). Successful deployment of the modular AneuRx system was noted in all patients. There were no immediate operative conversions, deaths within 24 hr of operation, or type I or III endoleaks observed at the completion of the procedure. Thirty-day mortality was 3.5% (n = 4). Acute deployment-related complications occurred in 10% (n = 13) of patients and included misdeployment, operative bleeding, arterial perforation/dissection, and access site complications. Acute systemic complications were present in nine patients, predominantly renal and cardiac complications. An endoleak noted at any time occurred in 25% of patients, with 40% of those requiring a secondary intervention. Two patients suffered late aneurysm rupture due to a type I endoleak and graft infection. Kaplan-Meier analysis revealed 5-year freedom from secondary intervention of 72.4%; freedom from aneurysm-related death of 93.9%; and probability of survival based on all-cause mortality of 60.1%. Endovascular treatment with the modular AneuRx Stent Graft System is safe and effective, producing acceptable rates of disease-free survival and mid-term clinical outcome.

Outcome and quality of life after surgical and endovascular treatment of descending aortic lesions

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) represents an attractive alternative to open aortic repair (OAR). The aim of this study was to assess outcome and quality of life in patients treated either by TEVAR or OAR for diseased descending thoracic aorta.

METHODS

A post hoc analysis of a prospectively collected consecutive series of 136 patients presenting with surgical diseases of the descending aorta between January 2001 and December 2005 was conducted. Fourteen patients were excluded because of involvement of the ascending aorta. Assessed treatment cohorts were TEVAR (n = 52) and OAR (n = 70). Mean follow-up was 34 +/- 18 months. End points were perioperative and late mortality rates and long-term quality of life as assessed by the Short Form Health Survey (SF-36) and Hospital Anxiety and Depression Score questionnaires.

RESULTS

Mean age was significantly higher in TEVAR patients (69 +/- 10 years versus 62 +/- 15 years; p = 0.002). Perioperative mortality rates were 9% (OAR) and 8% (TEVAR), respectively (p = 0.254). Accordingly, cumulative long-term mortality rates were similar in both cohorts. Overall quality-of-life scores were 93 (63-110, OAR) and 83 (60-112, TEVAR), respectively. Normal quality-of-life scores range from 85 to 115. Anxiety and depression scores were not increased after open surgery.

CONCLUSIONS

Thoracic endovascular aortic repair and OAR both provide excellent long-term results in treatment of thoracic aortic disease. Long-term quality of life, however, is reduced after thoracic aortic repair. Interestingly, TEVAR patients did not score higher in overall quality of life despite all advantages of minimized access trauma. Similarly, anxiety and depression scores are not reduced by TEVAR, possibly reflecting a certain caution against the new technology.

A Summary of the Contributions of the VA Cooperative Studies on Abdominal Aortic Aneurysms

The Department of Veterans Affairs Cooperative Studies Program has completed two studies on abdominal aortic aneurysm (AAA) and is currently conducting a third. The first, the Aneurysm Detection and Management (ADAM) Study, consisted of both a screening program, which provided information on the prevalence and associations of AAA, and a randomized trial, which found that survival is not improved by repair of small AAA. The second was a prospective observational study to determine the incidence of rupture in patients with large AAA for whom elective repair was not planned due to medical contraindications or patient refusal. AAA in this population had a high risk of rupture, about 10% per year for AAA > 5.5 cm, and 25% within 6 months for AAA larger than 8.0 cm. The third, the Open Versus Endovascular Repair (OVER) Trial, is a multicenter randomized trial comparing long-term survival following two methods of elective AAA repair.

Randomized EVAR Trials and Advent of Level I Evidence: A Paradigm Shift in Management of Large Abdominal Aortic Aneurysms?

The recent endovascular aneurysm repair (EVAR) 1 and 2 and Dutch Randomized Endovascular Aneurysm Management (DREAM) trials addressed management of abdominal aortic aneurysms (AAAs) larger than 5.5 cm in diameter. The DREAM and EVAR 1 trials randomized patients appropriate for open repair between endovascular repair (EVAR) and open repair (OR), and the EVAR 2 trial randomized patients unfit for OR between EVAR and conservative nonoperative management (No Rx). The EVAR 1 trial showed a 3% lower initial mortality for EVAR, with a persistent reduction in aneurysm-related death at 4 years. Improvement in overall late survival was not demonstrated. Similarly, the DREAM trial observed an initial mortality advantage for EVAR, but overall 1-year survival was equivalent in both groups. Both trials found significantly higher complication and intervention rates and higher hospital costs with EVAR, and by 1 year a quality of life (QOL) benefit was not evident. The EVAR 2 trial did not demonstrate a survival advantage of EVAR with respect to nonoperative management, while noting that EVAR was associated with greater likelihood of treatment complications, subsequent interventions, and threefold higher costs. Both EVAR trials were limited by long delays between randomization and treatment. Moreover, 27% of patients in EVAR 2 crossed over from nonoperative to endovascular repair, and these patients had a lower procedure mortality from EVAR than those originally assigned to it (2% v 9%). These 47 cases, and the exclusion of 14 patients dying while waiting for EVAR, appears to confer a survival advantage to those receiving EVAR over those receiving no treatment in a post-hoc analysis, but per-protocol analysis of the EVAR 2 trial data performed by the EVAR investigators did not show a significant difference in either all-cause or aneurysm-related mortality. Thus, outcomes of the EVAR 2 trial have not settled the choice between EVAR and no treatment in this scenario to everyone's satisfaction. In patients with large AAAs who are fit for OR, EVAR offers an initial mortality advantage over OR, with a persistent reduction in AAA-related death at 4 years. However, EVAR offers no overall survival benefit, is more costly, and requires more interventions and indefinite surveillance with only a brief QOL benefit. It may or may not offer a mortality benefit over nonoperative management in patients with large AAAs who are unfit for open repair, but the statistical significance of this comparison is inconclusive.

Mid-term results of endovascular repair of abdominal aortic aneurysm

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