Follow-up after endovascular aortic aneurysm repair can be stratified based on first postoperative imaging.

BACKGROUND: Lifelong postoperative surveillance is recommended following endovascular aneurysm repair (EVAR). Although the purpose is to prevent and/or identify complications early, it also results in increased cost and workload. This study was designed to examine whether it may be possible to identify patients at low risk of complications based on their first postoperative CT angiogram (CTA). METHODS: All patients undergoing EVAR in two Swedish centres between 2001 and 2012 were identified retrospectively and categorized based on the first postoperative CTA as at low risk (proximal and distal sealing zone at least 10 mm and no endoleak) or high risk (sealing zone less than 10 mm and/or presence of any endoleak) of complications. RESULTS: Some 326 patients (273 men) with a CTA performed less than 1 year after EVAR were included (low risk 212, 65·0 per cent; high risk 114, 35·0 per cent). There was no difference between the groups in terms of sex, age, co-morbidities, abdominal aortic aneurysm (AAA) diameter, preoperative AAA neck anatomy, stent-graft type or duration of follow-up (mean(s.d.) 4·8(3·2) years). Five-year freedom from AAA-related adverse events was 97·1 and 47·7 per cent in the low- and high-risk groups respectively (P < 0·001). The corresponding freedom from AAA-related reintervention was 96·2 and 54·1 per cent (P < 0·001). The method had a sensitivity of 88·3 per cent, specificity of 77·0 per cent and negative predictive value of 96·6 per cent to detect AAA-related adverse events. The number of surveillance imaging per AAA-related adverse event was 168 versus 11 for the low-risk versus high-risk group. CONCLUSION: Two-thirds of patients undergoing EVAR have an adequate seal and no endoleak on the first postoperative CTA, and a very low risk of AAA-related events up to 5 years. Less vigilant follow-up after EVAR may be considered for these patients.

Management of Aortic Sac Enlargement Following Successful EVAR in a Frail Patient.

BACKGROUND: An enlarging aneurysm after endovascular aneurysm repair (EVAR) without clear endoleak is a clinical challenge. Management of this problem is guided by the current evidence for adequate EVAR follow up and recommended thresholds for re-intervention. In a frail patient, careful risk assessment of aneurysm related mortality against the risks associated with examinations and interventions is required. METHODS: The literature was reviewed for imaging modalities for EVAR follow up and their advantages and disadvantages. The current evidence and guideline recommendations regarding follow up and re-intervention after EVAR were assessed in relation to the presented case. RESULTS: To detect sac expansion after EVAR, repeated examinations with the same imaging modality are needed. Verified expansion must be above the inter-observer variation of the method used. Although duplex ultrasound is an excellent modality for EVAR follow up, the finding of a significant expansion on duplex requires further examination, primarily with computed tomography angiography to assess sealing, stent graft integrity, and presence of endoleak. A frail patient should be assessed thoroughly before any kind of surgical intervention, the extent of which is related to the identified or suspected cause of expansion. CONCLUSION: Failure to totally exclude the aneurysm from continuing circulation, pressure and endoleak remains a potential shortcoming of EVAR. Significant sac expansion is an indication of EVAR failure. Decisions regarding further examinations or intervention are guided by the stability of the initial EVAR performed, the cause and extent of expansion, and the patient's comorbidities.

Early sac shrinkage predicts a low risk of late complications after endovascular aortic aneurysm repair.

BACKGROUND: Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). Patients with early postoperative shrinkage may experience fewer subsequent complications, and consequently require less intensive surveillance. METHODS: Patients undergoing EVAR from 2000 to 2011 at three vascular centres (in 2 countries), who had two imaging examinations (postoperative and after 6-18 months), were included. Maximum diameter, complications and secondary interventions during follow-up were registered. Patients were categorized according to early sac dynamics. The primary endpoint was freedom from late complications. Secondary endpoints were freedom from secondary intervention, postimplant rupture and direct (type I/III) endoleaks. RESULTS: Some 597 EVARs (71.1 per cent of all EVARs) were included. No shrinkage was observed in 284 patients (47.6 per cent), moderate shrinkage (5-9 mm) in 142 (23.8 per cent) and major shrinkage (at least 10 mm) in 171 patients (28.6 per cent). Four years after the index imaging, the rate of freedom from complications was 84.3 (95 per cent confidence interval 78.7 to 89.8), 88.1 (80.6 to 95.5) and 94.4 (90.1 to 98.7) per cent respectively. No shrinkage was an independent risk factor for late complications compared with major shrinkage (hazard ratio (HR) 3.11; P < 0.001). Moderate compared with major shrinkage (HR 2.10; P = 0.022), early postoperative complications (HR 3.34; P < 0.001) and increasing abdominal aortic aneurysm baseline diameter (HR 1.02; P = 0.001) were also risk factors for late complications. Freedom from secondary interventions and direct endoleaks was greater for patients with major sac shrinkage. CONCLUSION: Early change in aneurysm sac diameter is a strong predictor of late complications after EVAR. Patients with major sac shrinkage have a very low risk of complications for up to 5 years. This parameter may be used to tailor postoperative surveillance.