Shortest Apposition Length at the First Postoperative Computed Tomography Angiography Identifies Patients at Risk for Developing a Late Type Ia Endoleak After Endovascular Aneurysm Repair.

PURPOSE: Imaging surveillance following endovascular aneurysm repair (EVAR) is strictly recommended. This study investigates the value of endograft apposition and position relative to the aortic neck on the first postoperative computed tomography angiography (CTA) in determining patients at risk for a late type Ia endoleak (T1aEL). MATERIALS AND METHODS: Patients with a T1aEL after the first postoperative CTA were selected from a consecutive database and matched with uncomplicated controls. Endograft apposition and position, including the shortest apposition length (SAL), were determined on the first postoperative CTA. The SAL is the shortest distance between the proximal endograft fabric and the first slice where circumferential apposition with the aortic wall is lost. Differences in endograft apposition at the first postoperative CTA were compared between groups. Logistic regression analysis identified independent predictors for late T1aEL. RESULTS: A total of 32 patients with a late T1aEL were included and matched with 32 uncomplicated controls. Median follow-up after primary EVAR was 62.0 (interquartile range [IQR]: 36.8, 83.5) months in the T1aEL group compared with 47.5 (IQR: 34.0, 79.3) months in the control group; p=0.265. Median preoperative neck diameter was significantly larger in the T1aEL group than in the control group (26.6 [IQR: 24.9, 29.6] mm versus 23.4 [IQR: 22.5, 25.3] mm); p<0.001. Patients in the T1aEL group had a median SAL of 11.6 (IQR: 4.3, 20.5) mm compared with 20.7 (IQR: 13.1, 24.9) mm in the control group; p=0.002. SAL <10mm on the first postoperative CTA (odds ratio [OR]: 9.63, 95% confidence interval [CI]: 1.60-57.99) and larger neck diameter (OR: 1.80, 95% CI: 1.26-2.57) were independent predictors for developing a late T1aEL. CONCLUSION: Preoperative neck diameter and SAL on the first postoperative CTA following EVAR are important predictors for the development of a late T1aEL. Patients with a SAL of <10mm had a significantly higher risk of developing a late T1aEL. Future research should determine whether these patients would benefit from reintervention before an actual T1aEL is present. CLINICAL IMPACT: Understanding the mechanisms of endovascular aneurysm repair failure is essential to further enhance clinical outcomes. Adequate proximal sealing is necessary to foster freedom from type 1a endoleak. This study demonstrates that the shortest apposition length (SAL) at the first postoperative computed tomography angiography (CTA) is able to identify patients at risk for a late type 1a endoleak. Especially patients with a SAL <10mm are at high risk. Currently, the guidelines advice repeated imaging with CTA in patients with a seal <10mm. Future research should determine whether these patients would benefit from re-intervention before an actual type 1a endoleak is present.

Cost of Follow Up After Endovascular Abdominal Aortic Aneurysm Repair in Patients With an Initial Post-Operative Computed Tomography Angiogram Without Abnormalities.

OBJECTIVE: The Observing a Decade of Yearly Standardised Surveillance in EVAR patients with Ultrasound or CT Scan (ODYSSEUS) study was conducted to assess differences in outcomes of patients with continued or discontinued yearly follow up after endovascular abdominal aortic aneurysm repair (EVAR). Earlier results of this study showed that discontinued follow up was not associated with poor outcomes. Therefore, an incremental cost analysis and budget impact analysis of de-implementation of yearly imaging following EVAR was performed. METHODS: In total, 1 596 patients from the ODYSSEUS study were included. The expected cost savings were assessed if yearly imaging was reduced in patients with a post-operative computed tomography angiogram without abnormalities made around 30 days after EVAR. Costs were derived from the Dutch costs manual, benchmark cost prices, and literature review. Costs were expressed in euros (€) and displayed at 2019 prices. Sensitivity analysis was performed by varying costs. RESULTS: A difference of 24% in cost was found between patients with continued and discontinued imaging follow up. The cost per patient was €1 935 in the continued group vs. €1 603 per patient in the discontinued group at five years post-EVAR, with a mean difference of €332 (95% bias corrected and accelerated bootstrap confidence interval -741 to 114). De-implementation of yearly imaging would result in an annual nationwide cost saving of €678 471. Sensitivity analysis with variation in adherence rates, imaging, or secondary intervention costs resulted in a saving of at least €271 388 per year. CONCLUSION: This study provided an in depth analysis of hospital costs for post-EVAR patients in the Netherlands with a modest impact on the Dutch healthcare budget.

Editor's Choice - Post-operative Surveillance and Long Term Outcome after Endovascular Aortic Aneurysm Repair in Patients with an Initial Post-operative Computed Tomography Angiogram Without Abnormalities: the Multicentre Retrospective ODYSSEUS Study.

OBJECTIVE: Lifelong imaging surveillance is recommended following endovascular aneurysm repair (EVAR). This study aimed to examine the association between adherence to post-operative surveillance and survival and secondary interventions in patients with an initial post-operative computed tomography angiogram (CTA) without abnormalities. METHODS: All consecutive patients undergoing EVAR for intact abdominal aortic aneurysm (AAA) in 16 hospitals between 2007 and 2012 were identified retrospectively, with follow up until December 2018. Patients were included if the initial post-operative CTA showed no types I - III endoleak, kinking, infection, or limb occlusion. Discontinued follow up was defined as at least one 16 month period in which no imaging surveillance was performed. Primary outcomes were aneurysm related mortality and secondary interventions, and secondary outcome all cause mortality. Kaplan-Meier analysis was used to estimate survival, and Cox regression analyses to identify the association between independent variables and outcome. Sensitivity analyses were performed by varying the definition of continued yearly follow up. The study protocol was published (bmjopen-2019-033584). RESULTS: 1 596 patients (552 continued, 1 044 discontinued follow up) were included with a median (interquartile range) follow up of 89.1 months (52.6). Cumulative aneurysm related, overall, and intervention free survival was 99.4/94.8/96.1%, 98.5/72.9/85.9%, and 96.3/45.4/71.1% at 1, 5, and 10 years, respectively. American Society of Anesthesiologists (ASA) classification (ASA IV hazard ratio [HR] 3.810, 95% confidence interval [CI] 1.296 - 11.198), increase in AAA diameter (HR 3.299, 95% CI 1.408 - 7.729), and continued follow up (HR 3.611, 95% CI 1.780 - 7.323) were independently associated with aneurysm related mortality. The same variables and age (HR 1.063 per year, 95% CI 1.052 - 1.074) were significantly associated with all cause mortality. No difference in secondary interventions was observed between patients with continued vs. discontinued follow up (89/552; 16% vs. 136/1044; 13%; p = .091). Sensitivity analyses showed worse aneurysm related and overall survival in patients with continued follow up. CONCLUSION: Discontinued follow up is not associated with poor outcomes. Future prospective studies are indicated to determine in which patients imaging follow up can be safely reduced.

Analysis of Outcomes After Endovascular Abdominal Aortic Aneurysm Repair in Patients With Abnormal Findings on the First Postoperative Computed Tomography Angiography.

PURPOSE: Lifelong follow-up after endovascular abdominal aortic aneurysm repair (EVAR) is recommended due to a continued risk of complications, especially if the first postoperative imaging shows abnormal findings. We studied the long-term outcomes in patients with abnormalities on the first postoperative computed tomography angiography (CTA) following EVAR. MATERIALS AND METHODS: This is a retrospective study of all consecutive patients who underwent elective EVAR for nonruptured abdominal aortic aneurysm (AAA) between January 2007 and January 2012 in 16 Dutch hospitals with follow-up until December 2018. Patients were included if the first postoperative CTA showed one of the following abnormal findings: endoleak type I-IV, endograft kinking, infection, or limb occlusion. AAA diameter, complications, and secondary interventions during follow-up were registered. Primary endpoint was overall survival, and other endpoints were secondary interventions and intervention-free survival. Kaplan-Meier analyses were used to estimate overall and intervention-free survival. Cox regression analyses were used to identify the association of independent determinants with survival and secondary interventions. RESULTS: A total of 502 patients had abnormal findings on the first postoperative CTA after EVAR and had a median follow-up (interquartile range IQR) of 83.0 months (59.0). The estimated overall survival rate at 1, 5, and 10 years was 84.7%, 51.0%, and 30.8%, respectively. Age [hazard ratio (HR) 1.06, 95% confidence interval (CI) 1.05 to 1.10] and American Society of Anesthesiologists (ASA) classification (ASA IV HR 3.20, 95% CI 1.99 to 5.15) were significantly associated with all-cause mortality. Overall, 167 of the 502 patients (33.3%) underwent 238 secondary interventions in total. Fifty-eight patients (12%) underwent an intervention based on a finding on the first postoperative CTA. Overall survival was 38.4% for patients with secondary interventions and 44.5% for patients without (log rank; p=0.166). The intervention-free survival rate at 1, 5, and 10 years was 82.9%, 61.3%, and 45.6%, respectively. CONCLUSIONS: Patients with abnormalities on the first postoperative CTA after elective EVAR for infrarenal AAA cannot be discharged from regular imaging follow-up due to a high risk of secondary interventions. Patients who had a secondary intervention had similar overall survival as those without secondary interventions.

Type 2 Endoleak With or Without Intervention and Survival After Endovascular Aneurysm Repair.

OBJECTIVE: The aims of the present study were to examine the impact of type 2 endoleaks (T2EL) on overall survival and to determine the need for secondary intervention after endovascular aneurysm repair (EVAR). METHODS: A multicentre retrospective cohort study in the Netherlands was conducted among patients with an infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between 2007 and 2012. The primary endpoint was overall survival for patients with (T2EL+) or without (T2EL-) a T2EL. Secondary endpoints were sac growth, AAA rupture, and secondary intervention. Kaplan-Meier survival and multivariable Cox regression analysis were used. RESULTS: A total of 2 018 patients were included. The median follow up was 62.1 (range 0.1 - 146.2) months. No difference in overall survival was found between T2EL+ (n = 388) and T2EL- patients (n = 1630) (p = .54). The overall survival estimates at five and 10 years were 73.3%/69.4% and 45.9%/44.1% for T2EL+/T2EL- patients, respectively. Eighty-five of 388 (21.9%) T2EL+ patients underwent a secondary intervention. There was no difference in overall survival between T2EL+ patients who underwent a secondary intervention and those who were treated conservatively (p = .081). Sac growth was observed in 89 T2EL+ patients and 44/89 patients (49.4%) underwent a secondary intervention. In 41/44 cases (93.1%), sac growth was still observed after the intervention, but was left untreated. Aneurysm rupture occurred in 4/388 T2EL patients. In Cox regression analysis, higher age, ASA classification, and maximum iliac diameter were significantly associated with worse overall survival. CONCLUSION: No difference in overall survival was found between T2EL+ and T2EL- patients. Also, patients who underwent a secondary intervention did not have better survival compared with those who did not undergo a secondary intervention. This study reinforces the need for conservative treatment of an isolated T2EL and the importance of a prospective study to determine possible advantages of the intervention.

Secondary Interventions and Long-term Follow-up after Endovascular Abdominal Aortic Aneurysm Repair.

BACKGROUND: Early morbidity and mortality are low after endovascular abdominal aneurysm repair (EVAR), but secondary interventions and late complications are common. The aim of the present multicenter cohort study is to detail the frequency and indication for interventions after EVAR and the impact on long-term survival. METHODS: A retrospective multicenter cohort study of secondary interventions after elective EVAR for an infrarenal abdominal aortic aneurysm was conducted. Consecutive patients (n = 349) undergoing EVAR between January 2007 and January 2012 were analyzed, with long-term follow-up until December 2018. Those requiring intervention were classified in accordance with the indications and specific nature of the intervention and treatment. The primary study end point was overall survival classified for patients with and without intervention. Kaplan-Meier analysis was used to estimate overall survival for those who did and who did not undergo secondary interventions. Univariable and multivariable Cox regression were performed to identify independent variables associated with mortality. RESULTS: Some 56 patients (16%) underwent 72 secondary interventions after EVAR during a median (interquartile range) follow-up period of 53.2 months (60.1). Some 45 patients (80.4%) underwent one intervention. Indications for intervention included mainly endograft kinking/outflow obstruction and type II endoleak. An endovascular technique was used in 40.3% of interventions. Median time to secondary intervention was 24.1 months. In 93 patients with abnormalities on imaging, no intervention was performed mainly because the abnormality had disappeared on follow-up imaging (43%). Kaplan-Meier curves showed no difference in survival for patients with and without secondary interventions (P = 0.153). Age (hazard ratio [HR]: 1.089, 95% confidence interval [CI]: 1.063-1.116), ASA classification (ASA III, IV HR: 1.517, 95% CI: 1.056-2.178) were significantly related to mortality. CONCLUSIONS: Secondary intervention rates are still considerable after EVAR. Endograft kinking/outflow obstruction and endoleak type II are the most common indications for a secondary intervention. Secondary interventions did not adversely affect long-term overall survival after EVAR.

Diminishing Endograft Apposition during Follow-Up Is an Important Indicator of Late Type 1a Endoleak after Endovascular Aneurysm Repair.

Late type 1a endoleaks (T1aELs) after endovascular aneurysm repair (EVAR) are hazardous complications which should be avoided. This study investigated the evolution of the shortest apposition length (SAL) post-EVAR and hypothesised that a declining apposition during follow-up may be an indicator of T1aEL development. Patients with a late T1aEL were selected from a consecutive multicentre database. For each T1aEL patient, the preoperative computed tomography angiography (CTA), first postoperative CTA, and pre-endoleak CTA were analysed. T1aEL patients were matched 1:1 to uncomplicated controls, based on endograft type and follow-up duration. Anatomical characteristics and endograft dimensions, including the post-EVAR SAL, were measured. Included were 28 patients with a late T1aEL and 28 matched controls. The SAL decreased from 11.2 mm (5.6-20.6 mm) to 3.9 mm (0.0-11.4 mm) in the T1aEL group (p = 0.006), whereas an increase in SAL was seen in the control group from 21.3 mm (14.1-25.8 mm) to 25.4 mm (19.0-36.2 mm; p = 0.015). On the pre-endoleak CTA, 18 patients (64%) in the T1aEL group had a SAL < 10 mm, and one (4%) patient in the control group had a SAL < 10 mm on the matched CTAs. Moreover, three mechanisms of decreasing sealing zone were identified, which might be used to determine optimal imaging or reintervention strategies. Diminishing SAL < 10 mm is an indicator for T1aEL during follow-up, it is imperative to include apposition analysis during follow-up.