Interpretation of the CAESAR trial: when should we (if at all) treat small AAA?

Transcription

1 Interpretation of the CAESAR trial: when should we (if at all) treat small AAA? Piergiorgio Cao, MD, FRCS Chief of Vascular Surgery Azienda Ospedaliera S. Camillo Forlanini, Rome Professor of Vascular Surgery, University of Perugia

2 Randomized studies on EVAR vs surveillance in small AAA p=0.99 aneurysm-related death or aneurysm rupture JVS 2010

3 Randomized studies on EVAR vs surveillance in small AAA EJVES 2011 K-M estimates of survival in early EVAR and surveillance arm (54 months)

4 Randomized studies on EVAR vs surveillance in small AAA K-M estimates of repair in surveillance arm

5 Causes for open intervention (suitability loss) in 14/85 (16.5%) pts under surveillance requiring repair N % Neck shortening 8 57 Neck enlargement 2 14 Neck thrombus 1 7 Iliac access problem 1 7 New onset contrast allergy 1 7 Patient preference 1 7

6 Eur J Vasc Endovasc Surg (2011) 41, 2e10 54 potentially eligible reports Rupture rates available in 14 studies (9779 pt) Rupture rates specified for the diameter range cm available only in 7 studies

7 J.T. Powell et al. Eur J Vasc Endovasc Surg (2011) 41, 2e10 The rupture rate of small abdominal aortic aneurysms ( cm diameter) appears to lie between 0 and 1.61 per 100 person-years but the studies are very heterogeneous and suffer from absence of clear reporting standards for aneurysm rupture

8 Eur J Vasc Endovasc Surg (2011) We have not yet determined for how long a small aortic aneurysm will maintain that small size at negligible rupture risk. We cannot identify which small aneurysms grow faster than others to significantly increase their risk of rupture. The baseline diameter being obviously the main but not the only risk factor

9 Powell s review clearly confirmed that no rupture occurred within 12 months in aneurysms smaller than 4.0 cm. These data indicate that studies regarding the management of small AAAs should focus merely on the 1-cm aneurysm diameter range of cm. Not all small are equal

10 Combining 3.5 cm or less with 4.0 e 5.0 cm diameter aneurysms would confuse outcomes and growth rates

11 3 months

12 surveillance intervals of several years may be clinically acceptable for the majority of patients with small AAA but 3 cm is too small patients under US surveillance Probability to reach 5.5 cm and the risk of growth for >4cm is considerable if applied to a US surveilled population JAMA 2013

13 patients under US surveillance growth rates Growth rate was increased in smokers (by 0 35 mm/year) and decreased in patients with diabetes (by 0 51 mm/year) British Journal of Surgery 2012

14 patients under US surveillance Rupture rates were almost fourfold higher in women than men (P < 0 001), were double in current smokers (P = 0 001) and increased with higher blood pressure (P = 0 001) British Journal of Surgery 2012

15 5 057 patients under US surveillance Annual AAA growth Lipid-lowering drug treatment and initial AAA diameter appear to be independently associated with lower AAA growth rates JVS 2008

16 Subgroup analysis of CAESAR trial J Vasc Surg 2012 SURVIVAL GROWTH >5mm

17 Subgroup analysis of CAESAR trial For most diabetics with small AAA, the slower aneurysm enlargement and the higher CV mortality, suggest surveillance For nondiabetic, usually considered at lower CV risk, the higher aneurysm enlargement suggests Implementing screening protocols for small AAA Helpful finding in selecting strategies for management of small AAA

18 CAESAR Study messages for small AAA No difference in survival of patients after early EVAR vs those under surveillance

19 CAESAR Study suggestions in small AAA Small AAA may grow rapidly (three over five), quickly reaching thresholds of high rupture and loss of EVAR suitability: More than half (57%) of the patients under surveillance with AAA diameter cm will need aortic intervention within 36 months 90% of AAA > 5 cm will be operated in 36 months

20 CAESAR Study suggestions in small AAA At 72 months 80% of patient in surveillance has undergone aortic intervention Of these patients 17% has lost the suitability for EVAR

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