UK-COMPASS maps out complex aneurysm treatment in England, points to possible overtreatment

Rao Vallabhaneni

Data from the UK-COMPASS trial provide new insights into the management of complex aneurysm treatment in England and, according to lead investigator Srinivasa Rao Vallabhaneni (University of Liverpool, Liverpool, UK), underscore the need for appropriate patient and technique selection to avoid overtreatment.

UK-COMPASS is a cohort study of 2,202 patients treated across all hospitals in England over a consecutive two-year period. Speaking to Vascular News, Vallabhaneni reports that researchers were able to show “extremely good results” out to three years across three groups of patients based on aneurysm neck length: pararenal (0–4mm), juxtarenal (5–9mm), and those 10mm or more that were deemed unsuitable for an on-label, standard endovascular aneurysm repair (EVAR). Vallabhaneni notes that, in the pararenal group, both open repair and fenestrated repair are being delivered with “very good safety”.

Results from the study were presented for the first time at the 2022 Vascular Society of Great Britain and Ireland (VSGBI) annual scientific meeting (23–25 November, Brighton, UK). First, Shaneel Patel (Royal Liverpool University Hospital, Liverpool, UK) delivered a presentation on study and corelab methods, after which Michael Jenkins (Imperial College Healthcare NHS Foundation Trust, London, UK) outlined early results. He shared the headline finding that open repair does worst, EVAR does best, and FEVAR is “in between” with regard to perioperative (in-hospital and 30-day) mortality. He specified that these results were “fairly consistent” across neck lengths, and also noted a high rate of secondary interventions at this early stage.

Later in the session, Jon Boyle (Cambridge University Hospitals NHS Trust, Cambridge, UK) outlined results out to median follow-up. Reporting unadjusted all-cause mortality at three years, he noted a “significant divergence” of results just beyond a year favouring open repair in terms of survival, and at a three-year mortality rate of around 21%.

“In the long term, you have got about twice the risk of dying if you have had an EVAR over open repair, and similarly about twice the risk if you have had FEVAR [fenestrated EVAR] over open repair at long-term follow-up,” the presenter informed attendees at the November meeting.

Looking specifically at the different treatment groups, Boyle noted that, if a patient with no aortic neck has a standard EVAR, survival in the long term is “significantly worse” than with either open repair and FEVAR—groups in which he noted the outcomes are similar.

For longer aortic necks, Boyle stated that open repair in the longer term has better outcomes than both EVAR and FEVAR, and that in patients with aortic necks greater than 10mm in diameter, open repair has “significantly better” outcomes at three years.

In terms of secondary interventions, he said that “not surprisingly,” there were “significantly greater numbers” of reinterventions within the first three years if a patient had EVAR or FEVAR, and that results were “significantly worse” with FEVAR when compared to EVAR.

“In conclusion,” Boyle relayed, “there is no doubt that the longer-term all-cause mortality is significantly better for open repair,” noting a hazard ratio (HR) for EVAR of around 2.27 and for FEVAR of about 1.91. Outlining the results of a subgroup analysis, he said that FEVAR “does appear to be equivalent to open repair for short-necked aneurysms at three years,” again noting “significantly higher” reintervention rates for both EVAR (HR, 2.18) and FEVAR (HR, 2.67).

Closing the session, Vallabhaneni addressed the trial design of UK-COMPASS, informing delegates that there was very little support for an RCT due to a lack of equipoise, citing optimism among practitioners that FEVAR would give superior results. Putting this factor aside, the presenter also referenced various technological and methodological issues that would have made designing a “good quality” RCT “difficult,” including the issues associated with defining various anatomical inclusion criteria, and the frequent use of off-label standard EVAR in complex aneurysms, which he described as “quite rampant”.

Taking into account all of these factors, Vallabhaneni summarised that putting together an RCT was simply “not possible” at the trial design stage.

Are we repairing too many aortic aneurysms?

Considering the wider context of the trial results, Vallabhaneni addressed the question of overtreatment of aortic aneurysms in the President’s Symposium at the VSGBI meeting. “We have always presented to our patients that aneurysm repair is a decision balancing the risk of operative death on one side against the risk of rupture death,” he began, noting however that factors that influence decision-making in aneurysm repair are “actually a lot more complex and dynamic”.

“Effective clinical decision-making in aneurysm repair calls for personalised decision-making,” he stressed. While Vallabhaneni stated that the facets of the “clinical practice ecosystem” in which practitioners are making aneurysm repair decisions—namely evidence, governance structures, and professional attitudes and aspirations—are “all important in their own way,” they provide “in combination, very little scope to provide personalised decision-making in aneurysm practice”.

Reflecting on the UK-COMPASS study results, the presenter posited that “perhaps we are doing too many aneurysm repairs,” adding that there is “relatively good quality evidence to suggest that many a patient who survives the operation may not gain the overall survival benefit we hope for”.

Selection of the appropriate patients and techniques is crucial here, Vallabhaneni reiterated, specifying that clinic-ready tools are needed that would allow practitioners to make personalised decisions regarding aneurysm repair. “Until then,” he lamented, “we are doomed to continue to do too many aneurysm repairs.”


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