Is there a benefit of frequent CT follow-up after EVAR?

Estimation of the Added Cancer Risk Derived From EVAR and CTA Follow-Up

OBJECTIVE

The aim of this study was to assess the risk of radiation-induced cancer development in patients that have undergone an infrarenal EVAR, stratifying the relative contributions of the procedure and the preoperative and postoperative CTAs.

METHODS AND MATERIALS

The organ-specific absorbed radiation doses from CTA and the EVAR procedure were estimated from the radiation exposures of 95 and 45 male patients, respectively. Lifetime attributable risk (LAR) cancer predictions were calculated for 14 different organs. Life expectancy was assumed from a previous cohort of patients undergoing infra-renal EVAR.

RESULTS

The calculated total excess cancer risk was 0.0046, ie, 1 out of 220 patients will develop a neoplasm after being exposed to the ionizing radiation from the preoperative CTA, the EVAR and annual CTA examinations for 15 years. The procedure and the preoperative CTA contributed with 38% of the total excess risk, while the rest was derived from the follow-up. If the entire CTA based follow-up would have been eliminated, an excess risk of 0.0018 (1/560) would remain.

CONCLUSIONS

1 out of 219 patients who have undergone EVAR of an infra-renal AAA have a lifetime risk of developing cancer secondary to the radiation exposures related to the procedure and the CTAs used preoperatively and during follow-up. This risk derives mostly from the yearly postoperative CTAs, underlining the potential benefits of reducing or replacing their use.

CLINICAL IMPACT

A simulation-based estimation reinforced the potential deleterious effects of the radiation exposure for patients undergoing Endovascular Aneurysm Repair (EVAR) of Abdominal Aortic Aneurysms (AAA) and subsequently followed by yearly Computer Tomography Angiographies (CTAs). The risk could be as high as 1 out 219 patients developing a neoplasm after 15 years. The largest exposure derives from the follow-up CTAs and efforts to minimize their use as well as the intraoperative radiation are greatly needed. The simulation-based estimations done in this study reinforce potential deleterious effects of the radiation exposure for patients undergoing EVAR of AAA. Efforts should be done to minimize the intraoperative radiation and the number of CTAs used during follow-up.

Factors Influencing Compliance to Follow-Up After Endovascular Aneurysm Repair

OBJECTIVES

Regular follow-up after endovascular repair of aortic aneurysm is necessary to detect endoleak and/or migration of the stentgraft. However, absence or incomplete compliance to follow-up is common in this patient population. In this study we will analyse the frequency of non-compliance to post-EVAR follow-up and explore the underlying reasons.

METHODS

All patients undergoing EVAR for infrarenal aortic aneurysm between 1st January 2011 and 31st December 2020 were included in this retrospective study. Absence of compliance to FU was defined as not showing up at the out-patient clinic; incomplete FU was defined as a surveillance gap of >18 months.

RESULTS AND CONCLUSION

Non-compliance to follow-up was 35.9% (175 patients). In the multivariate analysis the patients who came with a ruptured aneurysm and patients who needed secondary therapy in the first 30 days more often did not comply with the FU protocol (P = .03 and P < .01). Other studies have confirmed the low attendance to follow-up after EVAR.

Endovascular Graft Suprarenal Bare Metal Stent Separation After Endovascular Aneurysm Repair: Case Reports and Literature Review

Objective

Suprarenal bare metal stent separation is a rare complication after endovascular aneurysm repair. In this report, two new cases of this type of device failure are presented and the literature is reviewed to identify similar cases and evaluate associated clinical characteristics.

Methods

A literature search was conducted in March 2022 using PubMed, Embase, and The Cochrane Library, with MeSH terms including aortic aneurysm, stents, and device failure. Two authors independently selected studies eligible for inclusion.

Results

Twelve patients with endovascular graft suprarenal bare metal stent separation were identified. Endovascular aneurysm repair (EVAR) devices were implanted between May 1996 and November 2017. Suprarenal bare metal stent separation was detected after a median duration of five years post-operatively.

Conclusion

Endovascular graft suprarenal bare metal stent separation demands a high level of awareness. A better understanding of the involved failure mechanisms and associated risk factors is required to further optimise EVAR follow up protocols.

Influence of Home Location on Follow-Up Compliance after Endovascular Treatment for Abdominal Aortic Aneurysm

BACKGROUND

The complications of EVAR require compliance to a close follow-up imaging. The purpose of this study was to determine whether home location predicted a poor compliance to imaging follow-up after EVAR.

METHODS

We analyzed a cohort of patients treated by EVAR at the Besançon University Hospital between 2007 and 2017. Follow-up imaging followed the French High Health Authority recommendations. Noncompliance with follow-up compliance was defined as a first missed postoperative appointment or 2 consecutive missed appointments after the first control CT-scan, and 2 groups of patients were identified: compliant (group C) or noncompliant (group NC). Univariate and multivariate analyzes were used to investigate compliance risk factors. Collected complications included endoleaks, limb thrombosis, infections, and secondary ruptures.

RESULTS

Two hundred and fifty-eight of the 359 patients treated during this period were enrolled, including 233 men (90.3%), with a mean age of 74.0 years (±9.0) and a mean follow-up of 5.0 years (±2.6). The compliance rate was 38.8% and the 1-year mortality rate was 12.0%. Using univariate and multivariate analysis, a place of residence greater located over 60 min away from the hospital had a poor effect on compliance (Odd ratio [OR] = 0.58; P = 0.047). Peripheral arterial occlusive disease (PAD) and an abdominal aortic aneurysm (AAA) diameter greater than 5.0 cm were protective factors (OR = 2.23; P = 0.006 and OR = 1.85, respectively; P = 0.002). Four-year all-cause mortality was 21.0% in group C and 17.0% in the NC group (P = 0.54). Complications were more significant in group C (59.0%) compared to group NC (39.0%) (P = 0.001). Two ruptures occurred in the NC group (1.3%), versus none in the C group (P = 0.25).

CONCLUSIONS

In this study, a long distance from the home to the hospital was a detrimental factor for follow up compliance. However, a good compliance did not decrease the 4-year mortality rate. The high rate of noncompliance found should lead to a more personalized follow-up strategy taking into account the anatomical elements but also the comorbidities and some social aspects.

Two decades of experience in explantation and graft preserving strategies following primary endovascular aneurysm repair and lessons learned

Objectives

We aim to scrutinize our evolving re-intervention strategies following primary endovascular aortic aneurysm repair (EVAR) - EVAR GORE SalvAge Fabric Technique (ARAFAT), aortic sac double breasting with endograft preservation, and stent-graft explantation.

Methods

We performed 1,555 aortic interventions over the study period, including 910 EVARs. Factors associated with the need for reintervention and the likelihood of chronic fabric fatigue failure (CFFF) were investigated. Using conventional and innovative diagnostic modalities with Prone contrASt enHanced computed tomography Angiography (PASHA), 136 endoleaks (ELs) were identified (15 type I, 98 type II; 18 type III; 5 type IV).

Results

Forty-four (4.84%) patients underwent re-intervention post-primary EVAR; 18 ARAFATs, 12 double breastings, and 14 explantations. Choice of re-intervention was based on patient fitness and mode of failure. Mean EL detection duration following primary EVAR was 53.3 ± 6.82 months, while mean time to re-intervention was 70.20 ± 6.98 months. The mean sac size before the primary EVAR and re-intervention was 6.00 ± 1.75 cm and 7.51 ± 1.94 cm, respectively. Polyester (61.40%) was the most commonly employed stent-graft material. Use of more than three modular stent-graft components (3.42 ± 1.31, p = 0.846); with the proximal stent-graft diameter of 31.6 ± 3.80 cm (p = 0.651) and the use of iliac limbs more than 17 mm (p = 0.364), all added together are contributing factors. We had one peri-operative mortality following explantation due to sepsis-induced multiorgan failure.

Conclusions

Our re-intervention strategies matured from stent graft explantation to graft preservation with endovascular relining of the stent-graft. Graft preservation with aortic sacotomy and double breasting were used to manage concealed ELs due to aortic hygroma.

Computed tomography follow-up after elective proximal aortic surgery: Less is more?

STUDY OBJECTIVE

The added value of computed tomography (CT) follow-up after elective proximal aortic surgery is unclear. We evaluated the benefit of CT follow-up by assessing the incidence of aorta-related complications and reinterventions detected during routine CT follow-up.

METHODS

Data on 314 patients undergoing first time elective proximal aortic surgery between 2000 and 2015 were collected. The primary study end points were aorta-related complications and reinterventions, detected during routine CT follow-up. Secondary study endpoints included all aorta-related complications and reinterventions, irrespective of the mode of detection and survival.

RESULTS

Median CT follow-up time was 6.8 (IQR 4.1-9.8) years, during which a total of 1303 routine follow-up CT-scans (median 4, IQR 3-5) were performed. During CT follow-up, aorta-related complications were detected in 18 (5.7%) patients, of which 6 (1.6%) underwent reintervention. In total, 28 aorta-related complications were observed in 23 (7.3%) patients, of which 9 led to reintervention. In order to detect 1 aorta-related complication leading to reintervention, 218 routine follow-up CT-scans were required. The unadjusted and EuroSCORE II adjusted hazard ratios of not undergoing CT follow-up on mortality were 1.260 (95% CI 0.705-2.251) and 0.830 (95% CI 0.430-1.605), respectively.

CONCLUSIONS

Following first time elective proximal aortic surgery, aorta-related complications are uncommon, are not always detected during CT follow-up and, if detected, often do not result in reintervention. Therefore, a more conservative CT follow-up protocol could be considered in selected patients to reduce lifetime radiation burden and health care costs.

Patient-Reported Outcomes of Yearly Imaging Surveillance in Patients Following Endovascular Aortic Aneurysm Repair

Little is known about the impact of standardized imaging surveillance on anxiety levels and well-being of patients after endovascular aortic aneurysm repair (EVAR). We hypothesize that patient anxiety levels increase just before receiving the imaging results compared with standard anxiety levels.

METHODS

Prospective cohort study from November 2018 to May 2020 including post-EVAR patients visiting the outpatient clinics of 4 Dutch hospitals for imaging follow-up. The Patient-Reported Outcomes Measurement Information System (PROMIS) was used. Patients completed the PROMIS Anxiety v1.0 Short Form (SF) 4a, PROMIS-Global Health Scale v1.2, and PROMIS-Physical Function v1.2 SF8b at 2 time points: prior to the result of the imaging study (T1: pre-visit) and 6-8 months later (T2: reference measurement). Mean T-scores at T1 were compared to T2, and T2 to the general 65+ Dutch population.

RESULTS

Altogether 342 invited patients were eligible, 214 completed the first questionnaire, 189 returned 2 completed questionnaires and 128 patients did not participate. Out of 214 respondents, 195 were male (91.1%) and the mean (standard deviation) age was 75.2 (7.0) years. There were no significant differences between T1 and T2 in anxiety levels (0.48; 95% confidence interval[CI] -0.42-1.38), global mental health (0.27; 95% CI -0.79-0.84), global physical health (0.10; 95% CI -0.38-1.18) and physical function (0.53; 95% CI -0.26-1.32). Compared with the 65+ Dutch population, at T2 patients experienced more anxiety (3.8; 95% CI 2.96-5.54), had worse global physical health (-3.2; 95% CI -4.38 - -2.02) and physical function (-2.4; 95% CI -4.00 - -0.80). Global mental health was similar (-1.0; 95% CI -2.21 - 0.21).

CONCLUSIONS

Post-EVAR patients do not experience more anxiety just before receiving surveillance imaging results than outside this period, but do suffer from more anxiety and worse physical outcomes than the 65+ Dutch population.

Safety and Validity of the Proposed European Society for Vascular Surgery Infrarenal Endovascular Aneurysm Repair Surveillance Protocol: A Single Centre Evaluation

OBJECTIVE

Long term surveillance after endovascular aneurysm repair (EVAR) is essential to detect late complications, but there is variation in practice. The European Society for Vascular Surgery (ESVS) made a recommendation for a new surveillance protocol; one element involves risk stratifying patients depending on sac size reduction and presence of endoleak at their 30 day computed tomography angiogram into low risk groups (delayed imaging to five years) or higher risk groups (continue with the current protocol). The aim was to test this suggested protocol retrospectively within an EVAR patient cohort.

METHODS

Data on EVARs performed from October 2009 to October 2019 were collected. Information gathered from an existing surveillance programme was used to assess the proposed ESVS protocol. All patients who underwent re-intervention were reviewed to see whether adopting the proposed ESVS protocol would have detected these events.

RESULTS

In total, 309 procedures were included. Altogether, 219 of these patients had no endoleak (70.9%) and 86 had a type II (27.8%) endoleak. Only four developed a type I or III endoleak. No patient in the low risk cohort (no initial endoleak or sac shrinkage > 1 cm) required secondary intervention. Five year follow up data were available for 103 patients. In the type II endoleak group, there were 28 secondary interventions in 22 patients. No patient experienced a ruptured aneurysm within five years post-operatively. Had the proposed ESVS protocol been followed, all patients requiring a secondary intervention or with increasing sac size would have been detected/captured. Further, adherence to the ESVS guidelines would have resulted in 103 patients with a five year follow up history qualifying for reduced surveillance. A further 120 patients who had reached the three and four year follow up timepoints could have qualified for a reduced surveillance, reducing imaging cost further.

CONCLUSION

Adopting the proposed ESVS EVAR surveillance protocol safely identified "low risk" patients who did not go on to require a secondary intervention. These patients could benefit from reduced surveillance scanning.

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.

Simple diameter measurements with ultrasound can be safely used to follow the majority of patients after infrarenal endovascular aneurysm repair

BACKGROUND

The optimal imaging follow-up after infrarenal EVAR is still undefined. The objective was to study the outcome of a personalized follow-up program after infrarenal EVAR based on ultrasound AAA diameter measurements for low-risk patients.

METHODS

All consecutive patients followed-up locally after elective and acute infrarenal EVAR between 2010 and 2015 were retrospectively reviewed. Patients underwent CTA at 1 month post-EVAR whereby the attending surgeon defined the subsequent follow-up. Patients considered at low risk were followed with ultrasound only assessing AAA diameter at 1, 2, 3 and every 5 years postoperatively (group A). Low-risk required a favourable preoperative anatomy especially regarding the aneurysm neck, satisfactory intraoperative result and uneventful 1 month CTA (type 2 endoleaks acceptable). Patients not fulfilling the criteria for group A were followed with yearly 3-phase-CTAs (group B).

RESULTS

222 patients with a AAA median diameter of 58 (54-68) mm were included. 191 were allocated into group A and 31 in group B. Median follow-up time was 36 (24-59) months. Five year primary and primary assisted success was 82 ± 5 % and 93 ± 3 % for group A and 70 ± 13% and 93 ± 5% for group B, respectively (P= 0.042 and P= 0.504, respectively). 16 late aneurysm-related re-interventions were performed in 12 patients (7 in group A and 9 in group B). In group A, 5 re-interventions were rupture-preventing and 2 were symptomatic. All late re-interventions in group B were performed following findings on follow-up imaging. Five-year late re-intervention-free survival was 95 ± 2 % and 84 ± 7 % for groups A and B, respectively (P=0.046). Five-year survival was 80 ± 3 % and 63 ± 10 % for group A and B, respectively (P= 0.024).

CONCLUSIONS

A customized follow-up program after infrarenal EVAR based on ultrasound AAA diameter measurements in low-risk patients seems to be effective in maintaining a very high mid-term clinical success rate.

Establishment of Carotid Artery Dissection and MRI Findings in a Swine Model

Carotid artery dissection (CAD) is the leading cause of ischemic stroke in young patients; however, the etiology and pathophysiology of CAD remain largely unknown. In our study, two types of dissections (length × width: 1.5 cm × 1/3 circumference of intima, Group I, n = 6; or 1.5 cm × 2/3 circumference of intima, Group II, n = 6) were created between the media and intima. Ultrasound (within 2 h after dissection) showed a dissociated intima in the lumen and obstructed blood flow in the surgical area. Digital subtraction angiography (DSA, 72 h after dissection), magnetic resonance imaging (MRI, 72 h after dissection), and hematoxylin–eosin (H&E, 7 days after dissection) staining confirmed stenosis (33.67 ± 5.66%) in Group I and total occlusion in Group II. In 10 out of 12 swine, the CAD model was established using a detacher and balloon dilation, and morphological outcomes (stenosis or occlusion) after CAD were determined by the size of intimal incision.

Type II Endoleak Nidus Volume on Arterial and Delayed Phases of Initial CT Angiography after Endovascular Abdominal Aortic Aneurysm Repair Predicts Persistent Endoleak and Aneurysm Sac Enlargement

Purpose

To evaluate type II endoleak nidus volume (ENV) in the arterial phase (ENV_AP) and delayed phase (ENV_DP) of the first postoperative CT angiography (CTA) as a predictor of persistent endoleak and aneurysm sac enlargement at follow-up CTA in patients with endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm.

Materials and Methods

Ninety-three patients (mean age ± standard deviation, 72 years ± 8; range, 56-88 years) with EVAR and type II endoleak were included in a single-institution retrospective study conducted between March 1, 2005, and December 31, 2018. ENV_AP, ENV_DP, change of volume (ENV_DP-AP), and percentage of ENV_AP and ENV_DP in aneurysm sac volume (ASV) (ENV_AP/ASV%, ENV_DP/ASV%, respectively) were measured on first postoperative CTA images. The mean follow-up was 31.6 months ± 26.6 (range, 6-163.8 months). Patients were divided into two groups (group A, spontaneous resolution of endoleak without intervention [n = 29] and group B, persistent endoleak at follow-up CTA [n = 64]) and compared by using the Mann-Whitney U, Wilcoxon signed rank, and Pearson χ² tests. Receiver operating characteristic (ROC) analysis was used to compare accuracies of parameters at first postoperative CTA.

Results

The accuracy of ENV_DP (area under the ROC curve [AUC], 0.78) was superior to the accuracy of ENV_DP/ASV% (AUC, 0.76), ENV_DP-AP (AUC, 0.74), ENV_AP (AUC, 0.71), and ENV_AP/ASV% (AUC, 0.69) in indicating persistent endoleak. In group B, 46 patients (72%) showed ASV enlargement and 44 patients (69%) underwent endoleak embolization. ENV_AP (1.7 cm³ ± 2.9 vs 3.4 cm³ ± 4.2; P = .001), ENV_DP (2.9 cm³ ± 3.8 vs 8.0 cm³ ± 9.6; P < .001), ENV_DP-AP (1.1 cm³ ± 1.8 vs 4.5 cm³ ± 7.8; P < .001), ENV_AP/ASV% (0.9% ± 1.5 vs 1.7% ± 2.2; P = .003), and ENV_DP/ASV% (1.6% ± 2.2 vs 3.7% ± 3.6; P < .001) were smaller in group A than in group B.

Conclusion

ENV_DP of the first postoperative CTA is an accurate predictor of persistent endoleak compared with ENV_AP, and persistent endoleak is associated with aneurysm sac enlargement, in which earlier intervention is recommended.© RSNA, 2021.

Early periaortic hematoma development after EVAR in the presence of severely calcified and modestly conical-shaped aortic neck: A potential trigger for sudden aneurysm progression toward rupture

OBJECTIVE

The aim of this report is to present a singular case of early post-endovascular aneurysm repair abdominal aortic aneurysm rupture and discuss the possible etiopathogenic mechanism promoting the sudden aneurysm progression toward rupture.Methods/Results: An 84-year-old man was submitted to endovascular aneurysm repair via second-generation endograft (Cordis-Incraft Stent-graft) during which, the left occluded common iliac artery was recanalized via balloon-expandable covered-stent-graft (Atrium-Advanta-V12). The aneurysm presented a severely calcified and modestly conical-shaped aortic-neck. The post-operative course was complicated by a broncho pneumonic infiltrate and a CT scan performed two weeks postoperatively accidentally revealed a relatively small hematoma surrounding the aortic wall. No active bleeding, endoleak, or aneurysm increase in diameter was documented. Nevertheless, the patient remained closely monitored. Three days later, he suffered from abdominal aortic aneurysm rupture. A CT scan revealed an arterial wall tear at the neck level. Intra-operatively the reanalyzed common iliac artery was intact and a good endograft-sealing was confirmed. Following this event, small lumbar arteries suture saccotomy was performed. The patient eventually died of multiorgan failure one month later.

CONCLUSIONS

The apparently "self-limiting" post-endovascular aneurysm repair CT-scan finding of periaortic hematoma may have represented a potential trigger for abdominal aortic aneurysm rupture. The possibility of developing undetected aortic lesions during endovascular aneurysm repair, specifically in the presence of potentially "at risk" anatomical conditions, should always be considered.

Color Doppler ultrasound for surveillance following EVAR as the primary tool

OBJECTIVE

As aneurysm-related events and rupture is not eliminated, postoperative lifelong surveillance is mandatory after endovascular aneurysm repair (EVAR). For surveillance colored Doppler ultrasound (CDUS) is a standard method of noninvasive evaluation having the advantages of availability, cost-effectiveness, and lack of nephrotoxicity and radiation. We evaluated CDUS for primary surveillance tool after elective EVAR by comparing with computerized tomography.

METHODS

Between January 2018 and March 2020, 84 consecutive post-EVAR patients were evaluated. First, CDUS was performed by two Doppler operators from the Radiology Department and then computed tomographic angiography (CTA) was performed. The operators were blind to CTA reports. A reporting protocol was organized for endoleak detection and largest aneurysm diameter.

RESULTS

Among 84 patients, there were 11 detected endoleaks (13.1%) with CTA and seven of them was detected with CDUS (r = .884, p < .001). All Type I and III endoleaks were detected perfectly. There is an insufficiency in detecting low flow by CDUS. Eliminating this frailty, there was a strong correlation of aneurysm sac diameter measurement between CTA and CDUS (r = .777, p < .001). The sensitivity and specificity of CDUS was 63.6% and 100%, respectively. The accuracy was 95.2%. Positive and negative predictive values were 100% and 94.8%. Bland-Altman analysis and linear regression analysis showed no proportional bias (mean difference of 1.5 ± 2.2 mm, p = .233).

CONCLUSIONS

For surveillance, CDUS promises accurate results without missing any potential complication requiring intervention as Type I or III endoleak. Lack of detecting Type II endoleaks may be negligible as sac enlargement was the key for reintervention in this situation and CDUS has a remarkably high correlation with CTA in sac diameter measurement. CDUS may be a primary surveillance tool for EVAR and CTA will be reserved in case of aneurysm sac enlargement, detection of an endoleak, inadequate CDUS, or in case of unexplained abdominal symptomatology. By this way we not only avoid ionizing radiation and nephrotoxic agents, but also achieve cost saving issue also.

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.

Best Practice Guidelines: Imaging Surveillance After Endovascular Aneurysm Repair

OBJECTIVE. Abdominal aortic aneurysm is a significant cause of morbidity and mortality in the United States. Endovascular aneurysm repair (EVAR) is the preferred treatment modality. Surveillance imaging after EVAR detects potential complications. The most common complication is endoleak, which can predispose the aorta to rupture. This article provides a comprehensive and evidence-based review regarding surveillance imaging after EVAR to help readers understand current societal guidelines, guide institutional protocols, and provide a framework to facilitate safe, cost-effective, and clinically relevant imaging of patients after EVAR. CONCLUSION. Lifelong surveillance is necessary for patients who have undergone EVAR. Triple-phase CT angiography (CTA) within 30 days after EVAR is necessary to triage patients appropriately and guide future imaging. Patients without endoleak on initial CTA can be monitored with annual duplex ultrasound. Patients with type I or type III endoleaks should be referred for intervention. Patients with type II and type V endoleaks should be referred for intervention only if the sac diameter grows by more than 1 cm. MR angiography should be used primarily as a problem-solving modality or in patients with contraindications to contrast media or radiation. Strong consideration should be given to more frequent surveillance in patients who have undergone EVAR who have aneurysms with a hostile neck anatomy compared with those patients with favorable neck anatomy.

Postoperative surveillance and long-term outcome after endovascular aortic aneurysm repair in the Netherlands: study protocol for the retrospective ODYSSEUS study

INTRODUCTION

Strict imaging surveillance protocols to detect complications following endovascular aneurysm repair (EVAR) are common practice. However, controversy exists as to whether all EVAR patients need intense surveillance. The 2019 European Society for Vascular Surgery guidelines for management of abdominal aortic aneurysm (AAA) suggest that patients may be considered for limited follow-up with imaging if classified as 'low risk' for complications based on their initial postoperative imaging. The current study aims to investigate the intervention-free survival and overall survival stratified for patients with and without yearly imaging surveillance.

METHODS AND ANALYSIS

The Observing a Decade of Yearly Standardised Surveillance in EVAR patients with Ultrasound or CT Scan study comprises a national multicentre retrospective cohort study in 17 medical centres. Consecutive patients with an asymptomatic or symptomatic infrarenal AAA who underwent EVAR between January 2007 and January 2012 will be included in this study with follow-up until December 2018. Clinical variables and all follow-up information will be retrieved in extensive data collection from the patient's medical records. In addition, an e-survey was sent to vascular surgeons at the 17 participating centres to gauge their opinions regarding the possibility of safely reducing the frequency of imaging surveillance. Primary endpoints are intervention after EVAR and aneurysm-related mortality. The initial estimated sample size is 1997 patients.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Ethics Review Committee of the Amsterdam UMC, location Academic Medical Centre, Amsterdam, the Netherlands. Study findings will be disseminated via presentations at conferences and publications in peer-reviewed journal.

TRIAL REGISTRATION NUMBER

The Netherlands Trial Registry, NL6953 (old: NTR28773).

Tight systolic blood pressure control with combination therapy decreases type 2 endoleaks in patients undergoing endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysm (AAA) disease. However, the survival advantage is lost in the long term due the occurrence of endoleaks affecting the late rupture of aneurism sac. Few data are available on the role of blood pressure control in affecting the incidence of type 2 endoleaks in patients undergoing EVAR.

OBJECTIVE

Aim of this study was to evaluated whether systolic blood pressure (SBP) control to target 130 mmHg reached after preoperative cardiology consultant might decrease the incidence of type II endoleak(T2E), sac expansion and related aortic reintervention after elective endovascular aneurysm repair(EVAR).

METHODS

We analyzed 386 patients undergoing EVAR between 2008 and 2016. The primary endpoints were T2E, sac expansion and related aortic re-intervention or sac shrinkage during a median follow-up of 24 months [12-48]. The secondary endpoint was every cause of vascular or cardiac morbidity and mortality.

RESULTS

The SBP value of 130 mmHg at the time of EVAR resulted, at ROC curve analysis, the most sensitive and specific for all the analyzed endpoints (T2E, n = 74; sac expansion n = 19; re-intervention, n = 10, sac shrinkage, n = 72). The combination antihypertensive therapy showed a significant inverse relationship with T2E occurrence. The incidence of primary endpoints was significantly higher (p < 0.001) in patients with SBP ≥ 130 mmHg. Cardiovascular death was significantly more prevalent (p < 0,001) in patients with SBP ≥130 mmHg. These findings were confirmed at the multivariable Cox regression analysis [primary endpoint HR = 0.09(0.06-0.15), p < 0.001; cardiovascular death HR = 0.33(0.12-0.85), p = 0.023].

CONCLUSIONS

Tight SBP control at the target of 130 mmHg at the time of elective EVAR significantly decreases TE2 occurrence, need of re-intervention and cardiovascular death in a prolonged follow-up of a large sample of patients.

Effect of Imaging Surveillance After Endovascular Aneurysm Repair on Reinterventions and Mortality: A Systematic Review and Meta-analysis

Purpose: To study the effects of imaging surveillance after endovascular aortic repair (EVAR) on reintervention and mortality. Materials and Methods: A systematic review was conducted comparing complication rates in EVAR patients compliant with the imaging surveillance protocol vs partially or noncompliant patients. Two authors independently selected articles and performed quality assessment and data extraction. Risk differences for reintervention and mortality between compliant and partially/noncompliant patients were meta-analyzed. The pooled risk difference (RD) is reported with the 95% confidence interval (CI). The review protocol is registered at Prospero (CRD42017080494). Results: A total of 11 cohort studies involving 21,838 patients were included. Studies differed in imaging, their surveillance protocols, and definitions of compliance subgroups. Median follow-up was 31.7 months (interquartile range 29.8, 49.3). The overall reintervention rate was 5%, while the overall mortality was 31%. The RD for the reintervention rate was 4% (95% CI 1% to 7%) in favor of partial/noncompliance [number needed to harm 25 (95% CI 14 to 100)], while mortality showed a nonsignificant RD of 12% (95% CI −2% to 26%) in favor of partial/noncompliance. Two studies reported that 41% to 53% of reinterventions were performed for complications detected through imaging surveillance; the other events were detected through patient symptoms. Conclusion: Patients who are compliant with imaging surveillance appear to undergo more reinterventions than those who are partially or noncompliant. However, imaging surveillance does not seem to protect against mortality. This suggests that the recommended yearly imaging surveillance may not be beneficial for all EVAR patients.

Positron Emission Tomography/Computed Tomography Predicts and Detects Complications After Endovascular Repair of Abdominal Aortic Aneurysms

Purpose: To assess if aortic 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) could play a role in predicting complications after endovascular aneurysm repair (EVAR). Materials and Methods: This study involved 2 cohorts of men with abdominal aortic aneurysm treated by EVAR: those who underwent a PET/CT scan before EVAR (n=17) and those who had a PET/CT during follow-up (n=34). Uptake of FDG was measured as the standardized uptake value (SUV). D-dimer, a marker of fibrinolysis, was measured in blood drawn concomitantly with the PET/CT. Results: A significant uptake of FDG in the aneurysm wall was detected by PET/CT before EVAR in 6 of 17 patients. During the first year after EVAR, type II endoleaks developed in 5 of these FDG+ patients vs 3 of 11 FDG- patients (p=0.04). Two of the FDG+ patients had continued sac growth and required conversion to open repair. A significant association between sac growth rate, SUV, and the presence of endoleak was found in the 34 patients who underwent PET/CT after EVAR. Finally, D-dimer was significantly increased in patients with both endoleak and positive PET/CT in the post-EVAR group. Conclusion: This study suggests that the presence of FDG uptake in the aortic wall might be a useful tool to predict patients at high risk of developing post-EVAR complications.

Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance.

DATA SOURCES

Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016.

METHODS

We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis.

RESULTS

We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups.

LIMITATIONS

Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data.

CONCLUSIONS

Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases.

FUTURE WORK

Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016036475.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Contemporary imaging methods for the follow-up after endovascular abdominal aneurysm repair: a review

Abdominal aortic aneurysm (AAA) is defined as a localized enlargement of the aortic cross-section where the diameter is greater than 3 cm or more than 50% larger than the diameter in a normal segment. The most important complication of AAA is rupture, which, if untreated, results in mortality rates of up to 90%. Conventional open surgical repair is associated with significant 30-day mortality. Endovascular aneurysm repair (EVAR) is a significantly less invasive procedure; it is related to a lower early mortality rate and a lower number of perioperative complications. Although EVAR is a minimally invasive technique, lifelong follow-up imaging is necessary due to possible late complications including endoleak, recurrent aneurysm formation, graft infection, migration, kinking and thrombosis. The total rate of complications after EVAR is estimated at approximately 30%, and the rate of complications that require intervention is 2–3%. Early detection and progression analysis of such situations is crucial for proper intervention.

Editor's Choice - The Implications of Non-compliance to Endovascular Aneurysm Repair Surveillance: A Systematic Review and Meta-analysis

OBJECTIVE/BACKGROUND

Increasingly, reports show that compliance rates with endovascular aneurysm repair (EVAR) surveillance are often suboptimal. The aim of this study was to determine the safety implications of non-compliance with surveillance.

METHODS

The study was carried out according to the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An electronic search was undertaken by two independent authors using Embase, MEDLINE, Cochrane, and Web of Science databases from 1990 to July 2017. Only studies that analysed infrarenal EVAR and had a definition of non-compliance described as weeks or months without imaging surveillance were analysed. Meta-analysis was carried out using the random-effects model and restricted maximum likelihood estimation.

RESULTS

Thirteen articles (40,730 patients) were eligible for systematic review; of these, seven studies (14,311 patients) were appropriate for comparative meta-analyses of mortality rates. Three studies (8316 patients) were eligible for the comparative meta-analyses of re-intervention rates after EVAR and four studies (12,995 patients) eligible for meta-analysis for abdominal aortic aneurysm related mortality (ARM). The estimated average non-compliance rate was 42.0% (95% confidence interval [CI] 28-56%). Although there is some evidence that non-compliant patients have better survival rates, there was no statistically significant difference in all cause mortality rates (year 1: odds ratio [OR] 5.77, 95% CI 0.74-45.14; year 3: OR 2.28, 95% CI 0.92-5.66; year 5: OR 1.81, 95% CI 0.88-3.74) and ARM (OR 1.47, 95% CI 0.99-2.19) between compliant and non-compliant patients in the first 5 years after EVAR. The re-intervention rate was statistically significantly higher in compliant patients from 3 to 5 years after EVAR (year 1: OR 6.36, 95% CI 0.23-172.73; year 3: OR 3.94, 85% CI 1.46-10.69; year 5: OR 5.34, 95% CI 1.87-15.29).

CONCLUSION

This systematic review and meta-analysis suggests that patients compliant with EVAR surveillance programmes may have an increased re-intervention rate but do not appear to have better survival rates than non-compliant patients.

Unexplained rupture after endovascular aneurysm repair

We present a case of a 70-year-old man who was admitted with rupture of an abdominal aneurysm 4 years after endovascular aneurysm repair. He was compliant with yearly follow-up computed tomography angiography. One month earlier, his computed tomography angiogram showed perfect exclusion of the aneurysm and no endoleak. We explanted the stent graft and confirmed effective sealing, and the graft was intact. We found no signs of infection during 2 years of follow-up. This rupture is nonpredictable and unexplained and illustrates that unremarkable imaging does not guarantee prevention of rupture. This case shows that the ultimate failure of endovascular aneurysm repair cannot be prevented despite surveillance protocols.

Radiation exposure in patients treated with endovascular aneurysm repair: what is the risk of cancer, and can we justify treating younger patients?

Background Endovascular aneurysm repair (EVAR) is becoming the mainstay treatment of abdominal aortic aneurisms (AAA). The postoperative follow-up regime includes a lifelong series of CT angiograms (CTAs) at different intervals in addition to EVAR, which will confer significant cumulative radiation exposure over time. Purpose To examine the impact of age and follow-up regime over time on cumulative radiation exposure and attributable cancer risk after EVAR. Material and Methods We calculated a mean effective dose (ED) for the EVAR procedure, CTA, and plain abdominal X-rays (PAX). Cumulative ED was calculated for standard, complex, and simplified surveillance over 5, 10, and 15 years for different age groups. Results For EVAR, the mean ED was 34 mSv (range, 12-75 mSv) per procedure. For PAX, the ED was 1.1 mSv (range, 0.3-4.4 mSv), and for CTA it was 8.0 mSv (range, 2-20 mSv). For a 55-year-old man, an attributable cancer risk (ACR) in standard surveillance at 5 and 15 years of follow-up was 0.35% and 0.65%, respectively. The corresponding values were 0.22% and 0.37% for a 75-year-old man. When using a simplified follow-up, the ACRs for a 55-year-old at 5 and 15 years were 0.30% and 0.37%, respectively. These values were 0.18% and 0.21% for a 75-year-old man. A complex follow-up with half-yearly CTA over similar age and time span doubled the ACR. Conclusion Treating younger patients with EVAR poses a low ACR of 0.65% (15-year standard surveillance) compared to a lifetime cancer risk of 44%. A simplified surveillance should be used if treating younger patients, which will halve the ACR over 15 years.

Endovascular aneurysm repair patients who are lost to follow-up have worse outcomes

BACKGROUND

Society for Vascular Surgery practice guidelines recommend 1- and 12-month follow-up with computed tomography imaging for the year after endovascular aneurysm repair (EVAR). We describe the incidence, risk factors, and outcomes of EVAR patients who are lost to follow-up (LTF).

METHODS

All patients undergoing elective EVAR in the Vascular Quality Initiative (VQI) data set (January 2003-December 2015) were stratified according to long-term follow-up method (in-person vs phone call vs LTF). Mortality was captured for all patients by linkage with the Social Security Death Index. Univariable statistics, Kaplan-Meier estimated survival curves, and Cox proportional hazard modeling were used to compare groups. Coarsened exact matching analysis was then performed to refine the association between LTF and risk of post-EVAR death.

RESULTS

During the study period, 11,309 patients underwent elective EVAR (78% in-person follow-up, 11% phone call follow-up, 11% LTF). On univariable analysis, LTF patients had larger baseline aneurysms, higher American Society of Anesthesiologists scores, more comorbidities, and worse baseline functional status compared to patients with in-person or phone call follow-up (P ≤ .05). Procedural factors (contrast material volume, blood transfusions, postoperative vasopressor use) were higher in the LTF group, as was the incidence of postoperative complications (P ≤ .05). Accordingly, LTF patients had longer postoperative lengths of stay and were less frequently discharged to home (P < .001). Five-year survival was lower for LTF vs phone call follow-up vs in-person follow-up (62% vs 68% vs 84%; P < .001). On multivariable analysis correcting for baseline differences between groups, there was a significantly higher risk of death for both the LTF group (hazard ratio, 6.45; 95% confidence interval, 4.89-8.51) and phone call follow-up group (hazard ratio, 3.48; 95% confidence interval, 2.66-4.57) compared with patients who followed up in person (P < .001). After coarsened exact matching on 30 preoperative and perioperative variables, 5-year survival after EVAR for LTF vs phone call follow-up vs in-person follow-up was 84.9% vs 84.8% vs 91.9%, respectively (log-rank, P < .001). Notably, patients with phone call follow-up had a lower prevalence of documented postoperative imaging compared with patients with in-person follow-up (56.1% vs 85.1%; P < .001).

CONCLUSIONS

EVAR patients with more comorbidities and a higher incidence of in-hospital complications tend to be more frequently LTF and ultimately have worse survival outcomes. In-person follow-up is associated with better post-EVAR survival and a higher rate of postoperative imaging. Phone follow-up confers a mortality risk equivalent to lack of follow-up, possibly as a result of inadequate postoperative imaging. Surgeons should stress the importance of office-based postoperative follow-up to all EVAR patients, particularly those with poor baseline health and functional status and more complicated perioperative courses.

Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study

Objective

To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair.

Materials and Methods

This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined.

Results

The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%.

Conclusion

Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation.

Diagnostic imaging methods applied in long-term surveillance after EVAR. Will computed tomography angiography be replaced by other methods?

Endovascular implantation of a stent graft in the abdominal aorta (endovascular aneurysm repair – EVAR) is a widely accepted alternative to open surgery in treatment of abdominal aortic aneurysms. Although EVAR is connected with a significant reduction in the risk of peri- and post-operative complications, it does not eliminate them totally. Long-term surveillance of post-EVAR patients is aimed at early detection of and fast reaction to a group of complications called endovascular leaks. Currently, the gold standard in leak diagnostics is computed tomography angiography (CTA). The other methods are ultrasonography, magnetic resonance (MR) angiography, intra-aneurysm sac pressure measurement, X-ray, and digital subtraction angiography (DSA). Despite many analyses based on long-term research, emphasising the high value and competitiveness of less invasive tests such as US or X-ray compared to CTA, it is still difficult for them to win the trust and acceptance of clinicians. The persisting view is that computed tomography is the test that finally resolves any inaccuracies. Consequently, a patient with a number of concurrent diseases is subject to absurdly high radiation exposure and effects of a radiocontrast agent within a short time. It is therefore logical to acknowledge that the EVAR-related risk is catching up with the open surgery risk, while the endovascular procedure is much more costly. Nevertheless, the status of CTA as the gold standard ultimately seems to be unthreatened. This paper presents a description of the diagnostic imaging tests that make it possible to detect any vascular leaks and to develop strategies for therapeutic processes.

Postoperative CT Evaluation After EVAR

Purpose: To compare the postoperative computed tomography angiography (CTA) assessment made by vascular surgeons and interventional radiologists after endovascular aneurysm repair (EVAR) at a tertiary vascular clinic to an outside core review facility. Methods: One hundred patients (mean age 78.7 years, range 88–55; 84 men) with consecutive, elective, routine CTA controls after EVAR were retrospectively studied. Consultant vascular surgeons or radiologists had evaluated all original scans and written the original report. All scans were then reevaluated by an independent core clinic. Findings were classified as vascular or extravascular and stratified as clinically significant or clinically nonsignificant by an independent external reviewer. Results: The number of vascular findings detected by the vascular clinic was 72 vs 69 by the core clinic. The vascular clinic reported more clinically significant findings (primarily stent compression or kinks) as well as endoleaks and their origin. The core clinic reported more pseudoaneurysms (24 vs 12). None of the patients with puncture complications needed reintervention. Interrater analysis of all findings between the 2 clinics showed good agreement when comparing endoleaks overall (without subclassification) and moderate agreement when assessing aneurysm growth. The core clinic reported extravascular findings in 58 patients; 37 of these were classified as clinically significant. The vascular clinic reported extravascular findings in 23 patients; 7 of these were clinically significant. The core clinic also reported 2 cases of suspected malignancies, which had not been reported by the vascular clinic. Conclusion: During routine CTA follow-up after EVAR, a significant number of vascular and nonvascular findings are detected. Whereas a highly dedicated vascular clinic identifies most vascular findings regardless of the specialty of the reader, some extravascular findings are missed. However, the frequency of clinically significant findings or findings that might warrant reintervention was low in this study.

Stent graft types for endovascular repair of abdominal aortic aneurysms

BACKGROUND

The UK prevalence of abdominal aortic aneurysm (AAA) is estimated at 4.9% in over 65-year olds. Progressive and unpredictable enlargement can lead to rupture. Endovascular repair of AAAs involves a stent graft system being introduced via the femoral artery and manipulated within the aorta under radiological guidance. Following endograft deployment, a seal is formed at the proximal and distal landing zones to exclude the aneurysm sac from the circulation. With the increasing popularity of endovascular repair there has been an increase in the number of commercially available stent graft designs on the market. This is an update of the review first published in 2013.

OBJECTIVES

This review aimed to assess the different stent graft types for endovascular repair of AAA.

SEARCH METHODS

The Cochrane Vascular Group Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched February 2015) and the Cochrane Register of Studies (2015, Issue 1). Trial databases were searched by the TSC for details of ongoing and unpublished studies.

SELECTION CRITERIA

All published and unpublished randomised controlled trials (RCTs) of stent graft types in the repair of AAAs were sought without language restriction and in consultation with the Cochrane Vascular Group TSC.

DATA COLLECTION AND ANALYSIS

We planned to conduct data collection and analysis in accordance with the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

No studies were identified that met the inclusion criteria. It was not possible to review the quality of the evidence in the absence of studies eligible for inclusion in the review.

AUTHORS' CONCLUSIONS

Unfortunately, no data exist regarding direct comparisons of the performance of different stent graft types. High quality randomised controlled trials evaluating stent graft types in abdominal endovascular aneurysm repair are required.

An Artificial Neural Network Stratifies the Risks of Reintervention and Mortality after Endovascular Aneurysm Repair; a Retrospective Observational study

Background

Lifelong surveillance after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is considered mandatory to detect potentially life-threatening endograft complications. A minority of patients require reintervention but cannot be predictively identified by existing methods. This study aimed to improve the prediction of endograft complications and mortality, through the application of machine-learning techniques.

Methods

Patients undergoing EVAR at 2 centres were studied from 2004-2010. Pre-operative aneurysm morphology was quantified and endograft complications were recorded up to 5 years following surgery. An artificial neural networks (ANN) approach was used to predict whether patients would be at low- or high-risk of endograft complications (aortic/limb) or mortality. Centre 1 data were used for training and centre 2 data for validation. ANN performance was assessed by Kaplan-Meier analysis to compare the incidence of aortic complications, limb complications, and mortality; in patients predicted to be low-risk, versus those predicted to be high-risk.

Results

761 patients aged 75 +/- 7 years underwent EVAR. Mean follow-up was 36+/- 20 months. An ANN was created from morphological features including angulation/length/areas/diameters/volume/tortuosity of the aneurysm neck/sac/iliac segments. ANN models predicted endograft complications and mortality with excellent discrimination between a low-risk and high-risk group. In external validation, the 5-year rates of freedom from aortic complications, limb complications and mortality were 95.9% vs 67.9%; 99.3% vs 92.0%; and 87.9% vs 79.3% respectively (p<0.001)

Conclusion

This study presents ANN models that stratify the 5-year risk of endograft complications or mortality using routinely available pre-operative data.

International validation of a risk score for complications and reinterventions after endovascular aneurysm repair

Background

Lifelong surveillance is considered mandatory after endovascular repair (EVAR) of abdominal aortic aneurysms to detect endograft complications and prevent aneurysm rupture. Current protocols are not cost-effective or clinically effective. The international validity of the St George's Vascular Institute (SGVI) score for EVAR complications was examined.

Methods

The ENGAGE registry recruited patients undergoing EVAR at 79 centres in 30 countries. Reinterventions and endograft complications were recorded for up to 3 years after surgery. Preoperative aneurysm morphology was extracted from the registry database, and used to predict whether patients would be at low or high risk of complications after EVAR based on the SGVI score. Kaplan–Meier analysis was used to compare the incidence of endograft complications and reinterventions in patients predicted to be at low risk compared with those predicted to be at high risk.

Results

Some 1207 patients underwent EVAR, with follow-up of up to 3 years. The SGVI score accurately discriminated freedom from reinterventions (90·5 versus 79·3 per cent in low- versus high-risk patients; P &lt; 0·001), freedom from endograft complications (77·9 versus 69·6 per cent in low- versus high-risk patients; P = 0·012), and freedom from a composite outcome measure of reinterventions or endograft complications (75·0 versus 66·1 per cent in low- versus high-risk patients; P = 0·006) during mid-term follow-up.

Conclusion

This study has provided international validation of a morphological risk score that predicts mid-term reinterventions and endograft complications. The results may enable risk-stratified surveillance after EVAR.