O-071 - INCREASED AORTIC EXCLUSION IN ENDOVASCULAR TREATMENT OF COMPLEX AORTIC ANEURYSMS CALLS FOR A REVISED AORTIC ANEURYSM CLASSIFICATION.

TOPIC:
Thoraco-abdominal Aortic Disease
AUTHORS:
Verhagen M. (Leiden University Medical Center ~ Leiden ~ Netherlands) , Eefting D. (Leiden University Medical Center ~ Leiden ~ Netherlands) , Van Rijswijk C. (Leiden University Medical Center ~ Leiden ~ Netherlands) , Van Der Meer R. (Leiden University Medical Center ~ Leiden ~ Netherlands) , Hamming J. (Leiden University Medical Center ~ Leiden ~ Netherlands) , Van Der Vorst J. (Leiden University Medical Center ~ Leiden ~ Netherlands) , Van Schaik J. (Leiden University Medical Center ~ Leiden ~ Netherlands)
Introduction:
In endovascular repair (ER) of complex aortic aneurysms additional segments of healthy aorta are covered to ensure an adequate proximal and distal seal, compared to open repair (OR). The current aortic aneurysm classification system does not take length of aortic exclusion into account, as it was developed for risk assessment and reporting in open repair. Taking into consideration that the length of aortic exclusion contributes to perioperative risk, there is a need for a uniform system applicable to open, as well as endovascular treatment. The aim of this study was to assess differences in aortic exclusion between ER and OR of complex aortic aneurysms, as a guidance for the development of a revised aortic aneurysm classification.
Methods:
This was a retrospective observational study, which included patients that underwent complex endovascular aortic aneurysm repair by means of a fenestrated endovascular aneurysm repair (FEVAR), combined fenestrated and branched EVAR (FBEVAR), or BEVAR, between 2013 and 2020. The length of aortic exclusion, number of patent segmental arteries and treated visceral arteries was determined per case in hypothetical OR and actual ER, by means of central luminal line reconstructions using 3-mensio vascular. A Wilcoxon signed-rank test was used to compare aortic exclusion and patent segmental arteries in ER and OR.
Results:
A total of 71 patients were included, which were treated with FEVAR (n=44), FBEVAR (n=8), or BEVAR (n=19), for Crawford type I (n=5), II (n=7), III (n=6), IV (n=7), V (n=2) thoracoabdominal, or juxtarenal (n=44) aneurysm (table 1). There was a significant increase in median exclusion of type I, II, III, IV and juxtarenal aneurysms (P<0.05) in ER, compared to hypothetical OR. There was a small increase in exclusion in ER of type V aneurysms (P>0.05). The number of patent segmental arteries in ER of type I-IV and juxtarenal aneurysms was significantly lower than in hypothetical OR (P<0.05). ER of juxtarenal aneurysms led to an increase in treated visceral arteries compared to hypothetical OR. The median extents of aortic exclusion in ER of complex aneurysms roughly translated to the lengths in OR according to the following principle: the median extent of a conventional Crawford type III aneurysm treated endovascularly was 402 mm, which agreed with the length of exclusion in OR of a Crawford type II (418 mm) (table 1). Juxtarenal aneurysms required a median extent of 207 mm, which corresponds to the length of open repair of a Crawford type IV (i.e., 202 mm). Conventional Crawford type's I, II, III, V could be considered a Crawford type II in case of ER (E-Crawford), a type IV as an E-Crawford type III, and a juxtarenal aneurysm as an E-Crawford type IV (figure 1).
Conclusion:
There are significant differences in length of aortic exclusion between ER and hypothetical OR of complex aortic aneurysms. This makes the general use of the classical Crawford classification, based on anatomical dimensions, ill-suited. A revised classification for complex aneurysms, as suggested in our study, which includes categories for OR (conventional Crawford) as well as ER (E-Crawford) is necessary for uniformity in reporting, and to facilitate comparison of treatments and prognostic risks.
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