The fate of endovascular aortic aneurysm repair after 5 years monitored with duplex ultrasound imaging

Longer follow-up intervals following EVAR are safe and appropriate after marked aneurysm sac regression

BACKGROUND

Abdominal aortic aneurysm (AAA) shrinkage after endovascular aortic aneurysm repair (EVAR) is a surrogate marker for successful exclusion. Our study characterized aneurysm sac remodeling after EVAR to identify a pattern that may be associated with benign AAA behavior and would safely allow a less rigorous follow-up regimen after EVAR.

METHODS

Elective infrarenal EVARs performed between 2008 and 2011 at our institution were retrospectively reviewed. AAA sac diameters using the minor axis measurement from ultrasound imaging or computer tomography angiogram imaging were compared with the baseline diameter from the 1-month postoperative computer tomography angiogram. The primary outcome was a composite of freedom from postoperative reintervention or rupture. We compared those with AAA sacs who regressed to predefined minimum diameter thresholds with those who did not. Outcomes were plotted with Kaplan-Meier curves and compared using log-rank testing and Fine-Gray regression using death as a competing risk, clustered on graft type. For patients whose AAA reached the minimum sac diameter, landmark analysis evaluated ongoing size changes including further regression and sac re-expansion.

RESULTS

A total of 540 patients (aged 75.1 ± 8.2 years; 82.0% male) underwent EVAR with an average preoperative AAA size of 55.2 ± 11.5 mm. The median postoperative follow-up was 5.3 years (interquartile range, 1.4-8.7 years) during which 64 patients underwent reintervention and 4 ruptured. AAA sac regression to ≤40 mm in diameter was associated with improved freedom from reintervention or rupture overall (log-rank, P < .01), which was maintained after controlling for the competing risk of death (P < .01). In 376 patients (70%) whose aneurysm sac remained >40 mm, 99 reinterventions were performed on 63 patients. Of 166 (31%) patients whose sac regressed to ≤40 mm, only 1 patient required a reintervention, and no one ruptured. The mean time to a diameter of ≤40 mm was 2.3 ± 1.9 years. Only eight patients (5%) developed sac re-expansion to >45 mm; all but two occurred at least 3 years after initially regressing to ≤40 mm.

CONCLUSIONS

In long-term follow-up, patients whose minimum AAA sac diameter regressed ≤40 mm after EVAR experienced a very low rate of reintervention, rupture, or sac re-expansion. Most sac re-expansion occurred at least 3 years after reaching this threshold and did not result in clinical events. Increasing follow-up frequency up to 3-year intervals once the AAA sac regresses to 40 mm would carry minimal risk of aneurysm-related morbidity.

Combined Detection of Plasma Tumor Necrosis Factor-α Converting Enzyme and Notch1 is Valuable in Screening Endoleak After Endovascular Abdominal Aortic Aneurysms Repair

OBJECTIVES

Endoleaks may be present in up to 25% of patients after endovascular abdominal aortic aneurysm repair (EVAR) and there is no clear consensus on valuable biomarkers to determine endoleak presence. The aim of this study was to examine the potential value of plasma tumor necrosis factor-α converting enzyme (TACE) and Notch1 concentrations in determining endoleak presence after EVAR.

METHODS

A total of 110 patients with abdominal aortic aneurysm who underwent EVAR were enrolled in our study, and plasma TACE and Notch1 concentrations were measured prior to and 6 months after EVAR. Logistic regression was performed to assess the association of postoperative plasma TACE and Notch1 concentrations with endoleak after adjusting for potential confounders. The ability of plasma TACE and Notch1 concentrations to determine endoleak presence was assessed using receiver operating characteristic curves and area under the curve (AUC).

RESULTS

Twenty-four patients developed endoleaks 6 months after EVAR. Both postoperative plasma TACE and Notch1 concentrations were higher in patients with endoleak than in those without endoleak (2376.4 ± 28.1 pg/ml vs. 2094.1 ± 27.3 pg/ml, P < 0.01; 218.6 ± 1.9 pg/ml vs. 195.0 ± 2.1 pg/ml, P < 0.01, respectively). The AUCs from receiver operating characteristic curve analysis of plasma TACE and Notch1 concentrations in determining endoleak presence were 0.844 (95% CI 0.771 to 0.918, P < 0.01) and 0.860 (95% CI 0.791 to 0.930, P < 0.01), respectively. Combining the detection of plasma Notch1 and TACE concentrations could improve the accuracy in determining endoleak presence (AUC 0.930, 95% CI 0.883 to 0.978, P < 0.01). The predicted probability cutoff of 0.22 yielded a sensitivity of 95.8% and a specificity of 82.6% for endoleak presence.

CONCLUSIONS

Plasma TACE and Notch1 levels can discriminate patients with and without endoleak 6 months after EVAR, and have a potential role in screening patients requiring computed tomography angiography.

Patient satisfaction and chronic illness are predictors of postendovascular aneurysm repair surveillance compliance

OBJECTIVE

Although lifelong surveillance is recommended by the Society for Vascular Surgery for patients undergoing endovascular aneurysm repair (EVAR) reported that compliance with long-term follow-up has been poor. We sought to identify factors that predict compliance with EVAR surveillance through analysis of patient variables and post-EVAR questionnaire results.

METHODS

We analyzed 28 patient variables gathered from our computerized registry, patient charts, and phone questionnaires of patients who underwent EVAR between January 1, 2010, and December 31, 2014. These factors included patient demographics, education, postoperative complications, satisfaction with vascular surgery care, transportation mode, distance to our medical center, and living situation. Compliance was defined as a patient who underwent the most recent recommended follow-up surveillance study within the prescribed timeframe. Post-EVAR surveillance protocol consisted of office evaluation and duplex ultrasound examination performed in our accredited noninvasive vascular laboratory at 1 week, 6 months, then annually. Computed tomography angiography was obtained only if duplex ultrasound examination suggested endoleak, sac enlargement of more than 5 mm, or a failing limb.

RESULTS

Of 144 patients who underwent EVAR during this time period, 89 patients (62%) were compliant with the most recent recommended follow-up study. One hundred two patients completed the questionnaire or their families did if patients died or were incapacitated. Of those, 80 were compliant with follow-up and 22 were not. Based on the questionnaires of these 102 patients, estimated compliance at 3 years after EVAR was 69.6 ± 6.0% based on Kaplan-Meier analysis. In the compliant vs noncompliant groups, the estimated 3-year survival rate was 93.2 ± 3.4% vs 52.4 ± 12.7%, respectively (P < .001), and the estimated 5-year survival rate was 83.1 ± 6.4% vs 34.4 ± 13.4%, respectively (P < .001), respectively. However, none of the mortalities observed in the noncompliant group were aneurysm related. Adverse neurologic events after EVAR demonstrated a trend predicting noncompliance after 5 years based on multivariate Cox regression analysis (hazard ratio [HR], 2.57; 95% confidence interval [CI], 0.95-6.90; P = .062). Patient dissatisfaction with their vascular surgeon and hospital care predicted noncompliance with recommended postoperative surveillance (HR, 5.0; 95% CI, 1.52-16.7; P = .008). College education or higher was associated with compliance (HR, 0.28; 95% CI, 0.06-1.23; P = .092). No other variables, including postoperative complications or distance from the hospital, predicted follow-up noncompliance.

CONCLUSIONS

Patient satisfaction with their vascular surgeon and hospital experience predicted compliance with post-EVAR surveillance regardless of postoperative complications. Noncompliant patients had decreased survival, but mortality and surveillance noncompliance were likely due to disabling chronic disease.

Late type II endoleaks after endovascular aneurysm repair require intervention more frequently than early type II endoleaks

OBJECTIVE

Type II endoleaks (T2ELs) are commonly observed after endovascular aneurysm repair (EVAR). We sought to determine whether time at onset of T2ELs correlated with the need to intervene based on sac expansion or rupture.

METHODS

Between 1998 and 2015, 462 EVARs performed at our institution had duplex ultrasound surveillance in our accredited noninvasive vascular laboratory. Computed tomography and arteriography were reserved for abnormal duplex ultrasound findings. The need for intervention for T2ELs was classified according to time at onset after EVAR. Interventions for T2ELs were performed only for sac expansion >5 mm or rupture. We defined early-onset T2ELs as <1 year after EVAR and delayed or late onset as >1 year of follow-up.

RESULTS

Of the 462 EVARs, 96 patients (21%) developed T2ELs after implantation. Of these, 65 (68%) had early and 31 (32%) had late onset (mean, 12 months; range, 1-112 months). Early T2ELs resolved without treatment in 75% (49/65) of cases compared with only 29% (9/31) of late T2ELs (P < .0001). Intervention was required for only 8% (5/65) of patients with early T2ELs (5 sac expansions, 0 ruptures) compared with 55% (17/31) for late T2ELs (16 sac expansions, 1 rupture; P < .0001). The remaining patients were observed for persistent T2ELs with no sac growth (17% [11/65] early vs 16% [5/31] late; P = .922).

CONCLUSIONS

Less than one-third (29%) of T2ELs that develop after 1 year will resolve spontaneously and about half (55%) will require intervention for sac growth or rupture. T2ELs that develop >1 year after EVAR should be followed up with a more frequent surveillance protocol and perhaps with a lower threshold to intervene.

Circulating biomarkers are not associated with endoleaks after endovascular repair of abdominal aortic aneurysms

OBJECTIVE

Endoleak is a common complication of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) but can be detected only through prolonged follow-up with repeated aortic imaging. This study examined the potential for circulating matrix metalloproteinase 9 (MMP9), osteoprotegerin (OPG), D-dimer, homocysteine (HCY), and C-reactive protein (CRP) to act as diagnostic markers for endoleak in AAA patients undergoing elective EVAR.

METHODS

Linear mixed-effects models were constructed to assess differences in AAA diameter after EVAR between groups of patients who did and did not develop endoleak during follow-up, adjusting for potential confounders. Circulating MMP9, OPG, D-dimer, HCY, and CRP concentrations were measured in preoperative and postoperative plasma samples. The association of these markers with endoleak diagnosis was assessed using linear mixed effects adjusted as before. The potential for each marker to diagnose endoleak was assessed using receiver operating characteristic curves.

RESULTS

Seventy-five patients were included in the study, 24 of whom developed an endoleak during follow-up. Patients with an endoleak had significantly larger AAA sac diameters than those who did not have an endoleak. None of the assessed markers showed a significant association with endoleak. This was confirmed through receiver operating characteristic curve analyses indicating poor diagnostic ability for all markers.

CONCLUSIONS

Circulating concentrations of MMP9, OPG, D-dimer, HCY, and CRP were not associated with endoleak in patients undergoing EVAR in this study.