March 19, 2020
NICE AAA Guidance Published: EVAR Options Preserved, But Controversy Continues
March 19, 2020—After nearly 2 years of discussion and debate regarding its draft guidance for abdominal aortic aneurysm (AAA) diagnosis and management, the United Kingdom's National Institute for Health and Care Excellence (NICE) has published its AAA guideline.
First circulated for comment in mid-2018, the draft guidance was controversial, meeting with criticism in large part for its proposing a substantially reduced role for endovascular aneurysm repair (EVAR) across most abdominal aortic indications, as well as its reliance on historic data sets believed to not reflect modern practice. However, the final guidance suggests a continued role for EVAR in certain standard as well as complex cases, while still favoring open repair in many settings.
In unruptured aneurysms, NICE suggests that some form of repair or management be considered for an aneurysm that is (1) symptomatic; (2) asymptomatic, > 4 cm and has grown by more than 1 cm in 1 year (measured inner-to-inner maximum anterior-posterior aortic diameter on ultrasound); or (3) asymptomatic and ≥ 5.5 cm or larger (measured inner-to-inner maximum anterior-posterior aortic diameter on ultrasound).
The guidance for standard AAA therapy is as follows:
1.5.3 Offer open surgical repair for people with unruptured AAAs meeting the criteria in recommendation 1.5.1, unless it is contraindicated because of their abdominal copathology, anesthetic risks, and/or medical comorbidities.
1.5.4 Consider endovascular aneurysm repair (EVAR) for people with unruptured AAAs who meet the criteria in recommendation 1.5.1 and who have abdominal copathology, such as a hostile abdomen, horseshoe kidney or a stoma, or other considerations, specific to and discussed with the person, that may make EVAR the preferred option.
1.5.5 Consider EVAR or conservative management for people with unruptured AAAs meeting the criteria in recommendation 1.5.1 who have anesthetic risks and/or medical comorbidities that would contraindicate open surgical repair.
Regarding complex endovascular aneurysm repair, NICE recommends the following:
1.5.6 If open surgical repair and complex EVAR are both suitable options, only consider complex EVAR if:
- the following has been discussed with the person:
- the risks of complex EVAR compared with the risks of open surgical repair
- the uncertainties around whether complex EVAR improves perioperative survival or long-term outcomes when compared with open surgical repair
- it will be performed with special arrangements for consent and for audit and research that will determine the clinical and cost-effectiveness of complex EVAR when compared with open surgical repair, and all patients are entered onto the National Vascular Registry.
1.5.7 For people who have anesthetic risks and/or medical comorbidities that would contraindicate open surgical repair, only consider complex EVAR if:
- the following has been discussed with the person:
- the risks of complex EVAR compared with the risks of conservative management
- the uncertainties around whether complex EVAR improves perioperative survival or long-term outcomes
- it will be performed with special arrangements for consent and for audit and research that will determine the clinical and cost-effectiveness of complex EVAR when compared with conservative management, and all patients are entered onto the National Vascular Registry.
Regarding ruptured aneurysms, the guidance suggests the consideration of EVAR or open repair but emphasizes that EVAR provides more benefit for most people, although an open repair may be more beneficial in men under 70 years of age, among other recommendations.
Guidance is also provided for endoleak management, anesthesia and analgesia, abdominal compartment syndrome, and surveillance.
Readers are encouraged to review not only the overall guidance but also its rationale sections, which are available on the NICE website. In these sections, the authors detail the evidence considered in creating the guidance but also the need for rebalancing practices toward open repair and the challenges inherent in doing so. These include (1) possible increased perioperative mortality with open surgical repair; (2) the risk that vascular units will have trouble meeting an increased demand for open repair; (3) potential shortage of beds in the National Health Service (NHS; presumably even before the COVID-19 outbreak); and (4) the possibility that reducing the number of EVAR procedures for unruptured aneurysms will make it difficult to provide EVAR for ruptured aneurysms.
Despite likely finding increased approval among those favoring the practice of EVAR when applicable, it appears controversy will continue to follow the published guidance. Although the AAA Guideline Development Committee (GDC) has welcomed the publication and believes it will "result in a much needed and long-overdue improvement in the management of people with AAA," it has also voiced "significant concerns with the way in which the NICE senior management team has conducted itself during the development [of the guideline]."
In a statement shared by committee member Dr. Christopher Hammond on Twitter, the GDC expressed unanimous disappointment in NICE's final recommendations for unruptured aneurysm repair, including the committee's belief that the recommendations do not reflect NICE's own technical analysis; are not concordant with NICE's own policies; do not accurately reflect the many discussions held between NICE and the GDC, nor the views of the GDC's professional or lay members. The GDC believes the recommendations "endorse the continuation of non–evidence-based, clinically and cost-ineffective practice that has the potential to put people with unruptured AAA at risk of avoidable harm and will result in the continued misallocation of NHS resources."
The GDC contends that its analysis shows open repair will result in a better clinical outcome, while costing less, for most unruptured candidates who are suitable for either option, and that for many candidates unfit for open repair, EVAR is neither a clinically effective nor cost-effective solution.
Commenting to Endovascular Today, several London-based vascular surgeons expressed their impressions of the NICE guideline and the lessons learned as it was developed and debated.
"I am generally relieved with the final guidance issued by NICE in that it comes much closer to allowing clinicians to select the best option for patients on an individual basis," said Tara M. Mastracci, MD, Clinical Lead, Complex Aortic Surgery, The Royal Free London NHS Foundation Trust, in London, United Kingdom. "The guidance takes into account patient factors but also real-world challenges that cannot be ignored."
Dr. Mastracci has been steadfast in her opinion that the 2018 draft guidance, if made permanent, would have been dangerous for patients due to the limits placed on patient-specific operator decision-making. However, she also believes that the process of formally addressing the draft guidance was perhaps a necessary look in the mirror for EVAR and its proponents. "Although we don't believe such critical guidance can be based solely on trials conducted using early-generation devices and historic decision-making, imaging technologies and follow-up protocols, we have been given a new imperative to address the shortfalls of more modern data sets, particularly those related to true long-term follow-up and outcomes," she said. "We are glad to continue to have the ability to offer EVAR as well as open repair, and we are committed to data-driven scrutiny of the remaining unanswered questions when it comes to anatomic suitability, cost-effectiveness, and long-term durability. This process has helped us understand the challenges of producing high-quality clinical research in a field where the pace of technological advancement is often greater than our ability to scrutinize it. We need to continue to prioritizing the routine and thorough auditing of outcomes, so we can evolve practices that put patient safety first.”
"I think there has been a reasonable compromise to account for patient and clinician choice and an acceptance that endovascular aneurysm repair will continue to have a role in vascular practice," added Ian Loftus, Professor of Vascular Surgery at St. George's Vascular Institute in London in comments to Endovascular Today. "Clearly this has been a wakeup call though. We need to see more responsible use of technology, better adherence to [instructions for use], robust reporting of complications and reinterventions, and better data on long-term outcomes."