Use of linked registry claims data for long term surveillance of devices after endovascular abdominal aortic aneurysm repair: observational surveillance study
BMJ 2022; 379 doi: https://doi.org/10.1136/bmj-2022-071452 (Published 25 October 2022) Cite this as: BMJ 2022;379:e071452Linked Editorial
Tracking the performance of endovascular devices
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Editors
Goodney et al clearly demonstrate the potential utility of routine administrative databases as a means to facilitate post-market device surveillance [1]. The median aneurysm diameter was 55mm with an interquartile range of 51 to 61mm. The interquartile range implies that approximately 1 in 4 study patients had an AAA diameter of 50mm or less. A further 1 in 4 had an aneurysm between 51 and 55mm.
Given that a large proportion of the included patients had AAA sizes below the generally agreed treatment threshold (55mm), it would be useful to learn whether an analysis of late rupture events according to AAA size at implantation has been undertaken. Contemporary screening data report a cumulative 8-year rupture rate of 0.62% for medium sized aneurysms (4.5 to 5.4cm) under surveillance [2]. This compares favourably to the overall cumulative post-EVAR 8 year-rupture rates of 3 to 6% (Figure 2, excluding the 9% figure for early AFX devices) reported here.
The two trials of EVAR versus surveillance for patients with small AAAs reported results with medium term follow up (about 3 years) but no longer-term follow up [3,4]. The large dataset compiled by the Vascular Quality Initiative Registry provides an opportunity to evaluate the long-term implications of EVAR for small to medium aneurysms and establish whether, in the long-term, it is a case of more harm than good.
References
1. Goodney P, Mao J, Columbo J, Suckow B, Schermerhorn M, Malas M, et al. Use of linked registry claims data for long term surveillance of devices after endovascular abdominal aortic aneurysm repair: observational surveillance study. BMJ. 2022;379:e071452.
2. Oliver-Williams C, Sweeting MJ, Jacomelli J, Summers L, Stevenson A, Lees T et al. Safety of Men With Small and Medium Abdominal Aortic Aneurysms Under Surveillance in the NAAASP. Circulation 2019 Mar 12;139(11):1371-1380.
3. Cao P, De Rango P, Verzini F, Parlani G, Romano L, Cieri E; CAESAR Trial Group. Comparison of surveillance versus aortic endografting for small aneurysm repair (CAESAR): results from a randomised trial. Eur J Vasc Endovasc Surg 2011 Jan;41(1):13-25.
4. Ouriel K, Clair DG, Kent KC, Zarins CK; Positive Impact of Endovascular Options for treating Aneurysms Early (PIVOTAL) Investigators. Endovascular repair compared with surveillance for patients with small abdominal aortic aneurysms. J Vasc Surg 2010 May;51(5):1081-7.
Competing interests: No competing interests
Re: Use of linked registry claims data for long term surveillance of devices after endovascular abdominal aortic aneurysm repair: observational surveillance study
Dear Editor,
We appreciate the response by Mansoor and colleagues regarding the utility of routine administrative datasets as a means to facilitate post-market surveillance after endovascular repair (EVAR) of abdominal aortic aneurysm (AAA). The editorialist is indeed correct in noting that approximately half of our patients underwent EVAR below the typically accepted thresholds – 50mm in females and 55 mm in males.
The editorialist also nicely outlines the relevant studies which characterizing the risk of rupture for patients with small aortic aneurysms. While many may debate the absolute thresholds and risk estimates, most will agree that a small AAA less than 55mm in a male has an annualized rupture risk which is less than 1% per year. As such, any therapy offered to patients with a small AAA must have a long-term risk profile which is less harmful simple observation.
Within our cohort, we explored associations between AAA size at the time of repair and long-term rupture rate. Late rupture was uncommon for patients with AAA <50mm in diameter, ranging from 1.0% to 3.1% in total at five years across device other than the early Endologix AFX device, which implies an annualized rupture rate which is less than 1% per year. For patients who underwent repair <55mm, this range was similar, ranging from 1-2% at five years, with an annualized rupture rate which was again less than 1% per year.
How these findings will be interpreted will be a matter of debate. For those favoring early intervention for AAA below the typical size threshold, our data will affirm that EVAR is effective in preventing late rupture for nearly all patients with small aneurysms. For those with less enthusiasm for early intervention, these data will reinforce that even an early EVAR does not always prevent rupture. The rupture risk for these small aneurysms after repair is not dramatically different than the natural history of a small, stable AAA maintained under surveillance.
Finally, it is worth noting that the highest late rupture risks occurred in the patients with the largest aneurysms, as we expected. Late rupture rates varied from 3.5% to 6.5% at five years for devices other than the early Endologix AFX. For clinicians, regulatory agencies, and patients, these findings reinforce the need for systematic surveillance of long-term EVAR outcomes in real-world practice.
Sincerely,
Philip P. Goodney, MD, MS on behalf of the VQI-VISION Steering Committee
Competing interests: No competing interests