Clinical practice change requires more than comparative effectiveness evidence: abdominal aortic aneurysm management in the USA

Low profile endografts for the endovascular treatment of abdominal aortic aneurysms

INTRODUCTION

Favorable midterm outcomes have been reported with the use of low-profile endografts (LPE), but long-term data is still needed. Furthermore, it is unclear if each of these LPE may have advantages over the other, which may, in turn, affect the outcomes. We systematically reviewed the literature about complications and reintervention rates of patients submitted to endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) using LPE.

MATHERIALS AND METHODS

A literature search was conducted including articles that reported 30-days and follow-up mortality, complications, and reintervention rates of patients treated with EVAR using Incraft (Cordis), Zenith LP/Alpha (Cook Medical Inc) and Ovation (Endologix) endografts.

RESULTS

36 papers were evaluated, reporting results of 582 patients treated with Zenith device, 1211 with Incraft and 3449 with Ovation. During follow up, similar survival and freedom from reintervention rates were reported among the various types of endograft both at 1 and 3 years. The incidence of limb stenosis/kinking was significantly higher in patients treated with Zenith LP/Alpha (2.1%, P = 0.008), while the Incraft device had a significantly lower proportion of type III endoleaks (P < 0.001).

CONCLUSIONS

Long-term survival and freedom from reintervention rates were comparable among the three LPEs. The Cook Zenith device had the highest rates of limb stenosis/kinking, while the Incraft device had the lowest occurrence of type III endoleak.

PROSPERO

Registration number: CRD42022315875.

Early and midterm outcomes of endovascular aneurysm repair with an ultra-low-profile endograft from the Triveneto Incraft Registry

OBJECTIVE

We evaluated the early and midterm outcomes of the Incraft (Cordis Corp, Bridgewater, NJ) ultra-low-profile endograft by analyzing data from the Triveneto Incraft Registry (TIR).

METHODS

TIR is an independent multicenter cohort registry of 10 vascular surgery units in the Triveneto area (Northeast Italy). A prospective analysis of patients electively treated with Incraft from September 2014 to June 2019 was performed. The main outcomes were technical success, major 30-day complications, 30-day aneurysm-related death, freedom from reintervention, and mortality rate during follow-up and were analyzed using Kaplan-Meier curves. Univariable Cox regression was used to evaluate the associations between anatomic complexity factors and reintervention.

RESULTS

During the study period, 209 patients were included in the registry. Their mean age was 76.9 ± 7.7 years and the Society for Vascular Surgery comorbidity score was 0.97 ± 0.52. Most patients (n = 181; 86.6%) had presented with at least one complex anatomic factor: aortic neck angle α <135° in 31 patients (14.8%), conic neck in 17 patients (8.2%), iliac tortuosity index τ >1.5 in 102 (48.8%), iliac artery calcification >50% in 106 (50.7%), and external iliac artery <6 mm in 45 (21.5%). The concurrent presence of two or more complex iliac anatomic factors was present in 67 patients (32.1%). The technical success rate was 99.5%, and the early major complication rate was 1.5% (one limb occlusion, one iliac branch stenosis, one type III endoleak [EL]). No 30-day mortality was recorded. The mean follow-up period was 18.5 ± 13.2 months. The overall mortality was 9.5% (n = 18), none related to the aneurysm. The freedom from reintervention rate was 92.1%. Of these patients, six (3.2%) had been treated for type II EL embolization, one (0.5%) for type IA EL, four (2.1%) for iliac branch occlusion, and one (0.5%) for flow-limiting external iliac artery dissection. None of the single anatomic factors analyzed were predictive of reintervention. However, the association of two or more complex iliac anatomic factors was predictive of related reintervention (hazard ratio, 7.25; P = .014). The crude reintervention rate in this complex subgroup of patients was low (4 of 67; 6%).

CONCLUSIONS

Data from the TIR have demonstrated excellent early and midterm outcomes of endovascular aneurysm repair using the Incraft stent graft in patients with complex anatomy. The concurrent presence of two or more complex iliac anatomic factors still represent an issue for endovascular aneurysm repair success. However, the technical characteristics of this device resulted in low intervention rates, even for patients with these challenging issues.

Surgery for small asymptomatic abdominal aortic aneurysms

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal ballooning of the major abdominal artery. Some AAAs present as emergencies and require surgery; others remain asymptomatic. Treatment of asymptomatic AAAs depends on many factors, but the size of the aneurysm is important, as risk of rupture increases with aneurysm size. Large asymptomatic AAAs (greater than 5.5 cm in diameter) are usually repaired surgically; very small AAAs (less than 4.0 cm diameter) are monitored with ultrasonography. Debate continues over the roles of early repair versus surveillance with repair on subsequent enlargement in people with asymptomatic AAAs of 4.0 cm to 5.5 cm diameter. This is the fourth update of the review first published in 1999.

OBJECTIVES

To compare mortality and costs, as well as quality of life and aneurysm rupture as secondary outcomes, following early surgical repair versus routine ultrasound surveillance in people with asymptomatic AAAs between 4.0 cm and 5.5 cm in diameter.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, two other databases, and two trials registers to 10 July 2019. We handsearched conference proceedings and checked reference lists of relevant studies.

SELECTION CRITERIA

We included randomised controlled trials where people with asymptomatic AAAs of 4.0 cm to 5.5 cm were randomly allocated to early repair or imaging-based surveillance at least every six months. Outcomes had to include mortality or survival.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, which were cross-checked by other team members. Outcomes were mortality, costs, quality of life, and aneurysm rupture. For mortality, we estimated risk ratios (RR) (endovascular aneurysm repair only), hazard ratios (HR) (open repair only), and 95% confidence intervals (CI) based on Mantel-Haenszel Chi² statistics at one and six years (open repair only) following randomisation.

MAIN RESULTS

We found no new studies for this update. Four trials with 3314 participants fulfilled the inclusion criteria. Two trials compared early open repair with surveillance and two trials compared early endovascular repair (EVAR) with surveillance. We used GRADE to access the certainty of the evidence for mortality and cost, which ranged from high to low. We downgraded the certainty in the evidence from high to moderate and low due to risk of bias concerns and imprecision (some outcomes were only reported by one study). All four trials showed an early survival benefit in the surveillance group (due to 30-day operative mortality with repair) but no evidence of differences in long-term survival. One study compared early open repair with surveillance with an adjusted HR of 0.88 (95% CI 0.75 to 1.02, mean follow-up 10 years; HR 1.21, 95% CI 0.95 to 1.54, mean follow-up 4.9 years). Pooled analysis of participant-level data from the two trials comparing early open repair with surveillance (maximum follow-up seven to eight years) showed no evidence of a difference in survival (propensity score-adjusted HR 0.99, 95% CI 0.83 to 1.18; 2226 participants; high-certainty evidence). This lack of treatment effect did not vary to three years by AAA diameter (P = 0.39), participant age (P = 0.61), or for women (HR 0.84, 95% CI 0.62 to 1.11). Two studies compared EVAR with surveillance and there was no evidence of a survival benefit for early EVAR at 12 months (RR 1.92, 95% CI 0.73 to 5.06; 846 participants; low-certainty evidence). Two trials reported costs. The mean UK health service costs per participant over the first 18 months after randomisation were higher in the open repair surgery than the surveillance group (GBP 4978 in the repair group versus GBP 3914 in the surveillance group; mean difference (MD) GBP 1064, 95% CI 796 to 1332; 1090 participants; moderate-certainty evidence). There was a similar difference after 12 years. The mean USA hospital costs for participants at six months after randomisation were higher in the EVAR group than in the surveillance group (USD 33,471 with repair versus USD 5520 with surveillance; MD USD 27,951, 95% CI 25,156 to 30,746; 614 participants; low-certainty evidence). After four years, there was no evidence of a difference in total medical costs between groups (USD 48,669 with repair versus USD 46,112 with surveillance; MD USD 2557, 95% CI -8043 to 13,156; 614 participants; low-certainty evidence). All studies reported quality of life but used different assessment measurements and results were conflicting. All four studies reported aneurysm rupture. There were very few ruptures reported in the trials of EVAR versus surveillance up to three years. In the trials of open surgery versus surveillance, there were ruptures to at least six years and there were more ruptures in the surveillance group, but most of these ruptures occurred in aneurysms that had exceeded the threshold for surgical repair.

AUTHORS' CONCLUSIONS

There was no evidence of an advantage to early repair for small AAA (4.0 cm to 5.5 cm), regardless of whether open repair or EVAR is used and, at least for open repair, regardless of patient age and AAA diameter. Thus, neither early open nor early EVAR of small AAAs is supported by currently available evidence. Long-term data from the two trials investigating EVAR are not available, so, we can only draw firm conclusions regarding outcomes after the first few years for open repair. Research regarding the risks related to and management of small AAAs in ethnic minorities and women is urgently needed, as data regarding these populations are lacking.

Initial Experience with the E-liac® Iliac Branch Device for the Endovascular Aortic Repair of Aorto-iliac Aneurysm

PURPOSE

Occlusion of internal iliac arteries during endovascular treatment (EVAR) of abdominal aortic (AAA) and common iliac artery aneurysms might be associated with ischemic pelvic complications. This study evaluates technical and clinical success, safety and mid-term results of a novel iliac branch device (IBD) for revascularization of the internal iliac artery (IIA) during EVAR.

MATERIALS AND METHODS

Retrospectively, we identified 21 men (mean age 73.3 ± 6.2 years) treated for aorto-iliac aneurysms by use of a novel IBD (E-liac^®, Jotec Hechingen, Germany). We analyzed safety (30-day survival), technical (no type I and III endoleaks, "EL"), clinical (no ischemic complications) success, mid-term patency of this IBD, peri-procedural complications, occurrence of type II ELs, rate of re-interventions and additional treatment of the revascularized IIA for landing zone preparation.

RESULTS

Twenty-three IBDs were implanted. Aneurysms of the ipsilateral IIA were present in 6/23 IIAs (26.1%). Super-selective branch embolization was performed in these patients and the landing zone for the iliac sidebranch stent-graft was within the superior gluteal artery. Mean follow-up was 341 days (range 4-1103 days). Technical success and 30-day survival were 100%. Clinical success was 95.2%. Primary patency of the IBDs was 100% at 12 months. Peri-procedural complications occurred in 3/21 patients (14.3%), none of them related to the IBD. AAA-related type II ELs were found in 6 patients (28.6%), IBD-related ELs in 4/23 IBDs (17.4%) (two type Ib, two type II endoleaks). Overall re-intervention rate was 23.8%, IBD-related 8.7%.

CONCLUSION

Utilization of the E-liac^® IBD is safe and effective for the treatment of aorto-iliac aneurysms.

Valuing technology: A qualitative interview study with physicians about insulin pump therapy for children with type 1 diabetes

Insulin pumps for children with type 1 diabetes have been broadly adopted despite equivocal evidence about comparative effectiveness. To understand why and inform policy related to public funding for new technologies, we explored how physicians interpret the value of pumps. We conducted open-ended, semi-structured interviews with 16 physicians from a pediatric diabetes network in Ontario, Canada, and analyzed the data using interpretive description. Respondents recognized that pumps fell short of expectations because they required hard work, as well as family and school support. Yet, pumps were valued for their status as new technologies and as a promising step in developing future technology. In addition, they were valued for their role within a therapeutic relationship, given the context of chronic childhood disease. These findings identify the types of beliefs that influence the adoption and diffusion of technologies. Some beliefs bear on hopes for new technology that may inappropriately hasten adoption, creating excess cost with little benefit. On the other hand, some beliefs identify potential benefits that are not captured in effectiveness studies, but may warrant consideration in resource allocation decisions. Still others suggest the need for remediation, such as those bearing on disparity in pump use by socioeconomic status. Understanding how technologies are valued can help stakeholders decide how to address such beliefs and expectations in funding decisions and implementation protocols.

Surgery for small asymptomatic abdominal aortic aneurysms

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal ballooning of the major abdominal artery. Some AAAs present as emergencies and require surgery; others remain asymptomatic. Treatment of asymptomatic AAAs depends on many factors, but an important one is the size of the aneurysm, as risk of rupture increases with aneurysm size. Large asymptomatic AAAs (greater than 5.5 cm in diameter) are usually repaired surgically; very small AAAs (less than 4.0 cm diameter) are monitored with ultrasonography. Debate continues over the appropriate roles of immediate repair and surveillance with repair on subsequent enlargement in people presenting with asymptomatic AAAs of 4.0 cm to 5.5 cm diameter. This is the third update of the review first published in 1999.

OBJECTIVES

To compare mortality, quality of life, and cost effectiveness of immediate surgical repair versus routine ultrasound surveillance in people with asymptomatic AAAs between 4.0 cm and 5.5 cm in diameter.

SEARCH METHODS

For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (February 2014) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 1). We checked reference lists of relevant articles for additional studies.

SELECTION CRITERIA

Randomised controlled trials in which men and women with asymptomatic AAAs of diameter 4.0 cm to 5.5 cm were randomly allocated to immediate repair or imaging-based surveillance at least every six months. Outcomes had to include mortality or survival.

DATA COLLECTION AND ANALYSIS

Three members of the review team independently extracted the data, which were cross-checked by other team members. Risk ratios (RR) (endovascular aneurysm repair only), hazard ratios (HR) (open repair only), and 95% confidence intervals based on Mantel-Haenszel Chi(2) statistic were estimated at one and six years (open repair only) following randomisation. We included all relevant published studies in this review.

MAIN RESULTS

For this update, four trials with a combined total of 3314 participants fulfilled the inclusion criteria. Two trials compared surveillance with immediate open repair; two trials compared surveillance with immediate endovascular repair. Overall, the risk of bias within the included studies was low and the quality of the evidence high. The four trials showed an early survival benefit in the surveillance group (due to 30-day operative mortality with surgery) but no significant differences in long-term survival (adjusted HR 0.88, 95% confidence interval (CI) 0.75 to 1.02, mean follow-up 10 years; HR 1.21, 95% CI 0.95 to 1.54, mean follow-up 4.9 years; HR 0.76, 95% CI 0.30 to 1.93, median follow-up 32.4 months; HR 1.01, 95% CI 0.49 to 2.07, mean follow-up 20 months). A pooled analysis of participant-level data from two trials (with a maximum follow-up of seven to eight years) showed no statistically significant difference in survival between immediate open repair and surveillance (propensity score-adjusted HR 0.99; 95% CI 0.83 to 1.18), and that this lack of treatment effect did not vary by AAA diameter (P = 0.39) or participant age (P = 0.61). The meta-analysis of mortality at one year for the endovascular trials likewise showed no significant association (RR at one year 1.15, 95% CI 0.60 to 2.17). Quality-of-life results among trials were conflicting.

AUTHORS' CONCLUSIONS

The results from the four trials to date demonstrate no advantage to immediate repair for small AAA (4.0 cm to 5.5 cm), regardless of whether open or endovascular repair is used and, at least for open repair, regardless of patient age and AAA diameter. Thus, neither immediate open nor immediate endovascular repair of small AAAs is supported by currently available evidence.

Welcome to the Journal of Comparative Effectiveness Research

As the Senior Editors of the Journal of Comparative Effectiveness Research (JCER) we are delighted to present you with the first issue of this exciting new publication, focusing on the socially and clinically impactful field of comparative effectiveness research (CER).

Interview: Achieving STEEEP healthcare: a journey supported by comparative effectiveness research

David J Ballard, MD, MSPH, PhD, FACP, is the Chief Quality Officer for Baylor Scott & White Health (TX, USA), the largest not-for-profit healthcare system in the state of Texas, founded on 1 October 2013 from the combination of Baylor Health Care System and Scott & White Healthcare. David joined Baylor Health Care System in 1999 as its first Chief Quality Officer and was responsible in that role for designing, implementing and evaluating initiatives related to clinical effectiveness, patient safety and other dimensions of healthcare quality improvement across the healthcare system. Under his leadership, the system earned several awards for healthcare quality improvement, including the 2010 Medical Group Preeminence Award of the American Medical Group Association, the 2008 National Quality Healthcare Award of the National Quality Forum, and the 2007 Leapfrog Patient-Centered Care Award. A board-certified internist, David trained at the Mayo Clinic (MN, USA) following completion of degrees in chemistry, economics, epidemiology and medicine at the University of North Carolina (NC, USA) where he was a Morehead Scholar and served as professor of medicine and epidemiology at Emory University (GA, USA). In addition to his role as Chief Quality Officer for Baylor Scott & White Health, he is President and Founder of the STEEEP® Global Institute (TX, USA), which is dedicated to helping other organizations deliver healthcare that is safe, timely, effective, efficient, equitable and patient-centered. Among several national and international leadership roles, he was President of the International Society for Quality in Healthcare (2001–2003), and is the 2013–2014 Chair of the Steering Committee for the Centers on Education and Research in Therapeutics for the US Agency for Healthcare Research and Quality. He serves on several editorial boards, including Health Services Research, the Journal of Comparative Effectiveness Research and the Mayo Clinic Proceedings (for which he serves as Health Policy Section Editor). David was the 1995 recipient of the AcademyHealth New Investigator Award, given annually to the outstanding health services research scholar in the USA less than 40 years of age, and the 2012 recipient of the John M Eisenberg Article-of-the-Year in Health Services Research. In 2008, he received the Distinguished Alumnus Award of the University of North Carolina School of Medicine.

Surgery for small asymptomatic abdominal aortic aneurysms

BACKGROUND

An abdominal aortic aneurysm (AAA) is an abnormal ballooning of the major abdominal artery. Some AAAs present as emergencies and require surgery; others remain asymptomatic. Treatment of asymptomatic AAAs depends on many factors but an important one is size of the aneurysm, as risk of rupture increases with aneurysm size. Large asymptomatic AAAs (> 5.5 cm in diameter) are usually operated on; very small AAAs (< 4.0 cm diameter) are monitored with ultrasonography. The optimal timing of surgery would benefit from further evidence.

OBJECTIVES

This review compared long-term survival in patients with AAAs of diameter 4.0 to 5.5 cm who received immediate repair versus routine ultrasound surveillance.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (February 2012) and CENTRAL (2012, Issue 1). Reference lists of relevant articles were checked for additional studies and the searches were supplemented by handsearches of recent conference proceedings and information from experts in the field. 

SELECTION CRITERIA

Randomised controlled trials in which men and women with asymptomatic AAAs of diameter 4.0 to 5.5 cm were randomly allocated to immediate repair or imaging-based surveillance at least every six months. Outcomes had to include mortality or survival.

DATA COLLECTION AND ANALYSIS

Two authors (GF, MAMM) abstracted the data, which were cross-checked by the other authors (DJB, JTP). Due to the small number of trials, formal tests of heterogeneity and sensitivity analyses were not conducted.

MAIN RESULTS

Four trials with a combined total of 3314 patients, the UK Small Aneurysm Trial (UKSAT), the Aneurysm Detection and Management (ADAM) trial, the Comparison of Surveillance Versus Aortic Endografting for Small Aneurysm Repair (CAESAR), and the Positive Impact of Endovascular Options for treating Aneurysms Early (PIVOTAL) fulfilled the inclusion criteria. The four trials showed an early survival benefit in the surveillance group (due to 30-day operative mortality with surgery) but no significant differences in long-term survival (adjusted hazard ratio (HR) 0.88, 95% confidence interval (CI) 0.75 to 1.02, mean follow up 10 years (UKSAT); HR 1.21, 95% CI 0.95 to 1.54, mean follow up 4.9 years (ADAM); HR 0.76, 95% CI 0.30 to 1.93, median follow up 32.4 months (CAESAR); HR 1.01, 95% CI 0.49 to 2.07, mean follow up 20 months (PIVOTAL)). The meta analyses of mortality at one year (CAESAR and PIVOTAL only) and six years (UKSAT and ADAM only) revealed a non-significant association (Peto odds ratio at one year 1.15, 95% CI 0.59 to 2.25; Peto odds ratio at six years 1.11, 95% CI 0.91 to 1.34).  

AUTHORS' CONCLUSIONS

The results from the four trials to date demonstrate no advantage to early repair (via open or endovascular surgery) for small AAA (4.0 to 5.5 cm) and suggest that 'best care' for these patients favours surveillance. Furthermore, the more recent trials focused on the efficacy of endovascular aneurysm repair and still failed to show benefit. Thus, both open and endovascular repair of small AAAs are not supported by currently available evidence.