Estimating the risk of solid organ malignancy in patients undergoing routine computed tomography scans after endovascular aneurysm repair

Are current follow-up intervals justified in patients with non-emergent aortic surgeries?

OBJECTIVES

Evidence for different surveillance protocols following aortic treatment is still lacking. The aim of this study was to analyse the clinical relevance of a first follow-up visit after 6 months.

METHODS

Between January 2018 and December 2019, 464 patients treated for non-emergent aortic pathologies were retrospectively analysed. The incidence of aortic events during follow-up (ie, death, reintervention, endoleaks, anastomotic/new aneurysms and diameter progression over time) was investigated. A discrete-time non-homogeneous Markov Chain Model was used to analyse the data and to arrive at the number of skipped 6-month follow-up visits needed to harm a patient.

RESULTS

After 6 months, 2 (1.77%) patients had died, 15 (15.31%) patients suffered from aortic events and a total of 4 (3.67%) patients had undergone reintervention after endovascular surgery, compared to 0 deaths, 2 (0.59%) patients with aortic events and 5 (1.48%) reinterventions after open surgery. In our Markov Chain Model, after 6 months, 4.75% of patients showed aortic events, received a reintervention or died. Sixty patients would need to skip their 6-month follow-up visit for one indication for reintervention to go unnoticed. Only 24 would need to skip it for one complication to go by unnoticed. This number is 55 after open surgery and 9 after endovascular surgery.

CONCLUSIONS

After elective endovascular or open aortic surgery without immediate in-hospital postoperative aortic events, the first follow-up visit after 6 months is important. Extending the first interval to longer time periods might lead to a considerable increase in missed aortic events. The cost and radiation exposure of frequent follow-ups must be balanced against the benefits of early preventative aortic interventions, warranting further research.

Long-Term Outcomes and Late Complications of Thoracic Endovascular Aortic Repair Using the GORE TAG or Conformable GORE TAG

PURPOSE

Previous clinical studies have reported on the short- and mid-term prognoses of thoracic endovascular aortic repair (TEVAR) using the GORE thoracic aortic graft (TAG) or conformable GORE TAG. We evaluated the long-term prognoses of patients who underwent TEVAR using the GORE TAG or conformable GORE TAG in a real-world setting.

MATERIALS AND METHODS

This retrospective observational study analyzed the data of all consecutive patients aged 20 years or older who underwent TEVAR using either the GORE TAG or the conformable GORE TAG at a single center. The surgical criteria did not deviate from global standards. In principle, TEVAR was performed with the TAG or conformable thoracic aortic graft (CTAG) according to the manufacturer's instructions. The primary outcomes of this study were the 10-year overall survival rate and the rate of freedom from aorta-related deaths at 10 years.

RESULTS

Between January 2011 and December 2021, 331 patients underwent TEVAR, of whom 175 consecutive patients treated with TEVAR using either the GORE TAG or the conformable GORE TAG were enrolled. The mean age of the patients was 72.1 ± 9.3 years. In addition, the aneurysm and chronic dissection were 61.7% and 38.3%, respectively. Of all patients, 157 had a proximal landing zone ≥3, and 18 had a zone <3. The mean follow-up time was 46.5 ± 33.1 months. The 30-day mortality rate was 2.86%. The 3-, 5-, 7-, and 10-year overall survival rates were 76.9 ± 3.4%, 63.4 ± 4.1%, 55.9 ± 4.9%, and 42.4 ± 8.4%, respectively. The rate of freedom from aorta-related deaths at 3, 5, 7, and 9 years was 97.4 ± 1.3%, 95.0 ± 2.1%, 95.0 ± 2.1%, and 95.0 ± 2.1%, respectively. Late complications occurred in 23 (13.1%) patients. Endovascular re-intervention was performed because of endoleak, false lumen enlargement, or stent graft-induced new entry tear in 14 patients. Three patients required open conversion, and 6 were observed without re-intervention.

CONCLUSIONS

Thoracic endovascular aortic repair using the GORE TAG or conformable GORE TAG is a safe and effective procedure for the treatment of thoracic aortic aneurysms and aortic dissection.

CLINICAL IMPACT

Thoracic endovascular aortic repair using the GORE thoracic aortic graft (TAG) or conformable GORE TAG is a safe and effective procedure for the treatment of thoracic aortic aneurysms and aortic dissection. The 30-day mortality rate was 2.86%. During 10 years of follow-up, the overall survival rate was low; however, the risk of aorta-related deaths was also low. No significant differences in freedom from late complications and re-intervention are seen between the TAG and conformable thoracic aortic graft (CTAG) groups. Further investigations into the treatment of late complications are required.

Duplex Ultrasound-Only Surveillance after Endovascular Abdominal Aortic Aneurysm Repair is Associated with Favorable Long-Term Outcomes

BACKGROUND

Long-term data surrounding the impact of different endovascular abdominal aortic aneurysm repair (EVAR) surveillance strategies are limited. Therefore, the purpose of this study was to characterize postoperative imaging patterns, as well as to evaluate the association of duplex ultrasound surveillance after the first postoperative year with 5-year EVAR outcomes.

METHODS

EVAR patients (2003-2016), who survived at least 1 year without aneurysm rupture, conversion to open repair, and reintervention in the Vascular Implant Surveillance and Interventional Outcomes Network were examined to provide all subjects ≥3 years of follow-up time. Patients were categorized into 6 cohorts after the first postoperative year: No imaging (N = 953); computed tomography (CT)/magnetic resonance imaging (MRI)-only (N = 2,976); duplex ultrasound-only (DUS; N = 1,808); combined CT/MRI + DUS with >50% being CT/MRI (N = 1,937); combined CT/MRI + DUS with >50% being DUS (N = 2,253); and mixed (CT + DUS + MRI N = 1,272). Abdominal aortic aneurysm (AAA)-related reintervention, rupture, conversion to open repair, and all-cause mortality were estimated using Kaplan-Meier analysis. Multivariable logistic regression models identified variables associated with using DUS-only imaging (versus CT/MRI only). Cox regression models compared 5-year outcomes between patients receiving DUS-only versus CT/MRI-only imaging.

RESULTS

A total of 11,199 EVAR patients were examined (mean age 76 ± 7 years; female: 20%; nonelective: 10%). DUS-only imaging surveillance after the first postoperative year was more likely to occur after elective repairs, as well as among older, male patients. Smaller (<6 cm) preoperative AAA diameter and absence of documented concurrent iliac aneurysm was also associated with DUS-only follow-up. Additionally, no endoleak detection on index EVAR completion imaging, as well as a documented >5 mm decrease in AAA sac diameter at 1-year follow-up was more common with DUS-only surveillance protocols. Post-EVAR DUS-only imaging after the first postoperative year had the lowest incidence of reintervention, conversion to open repair, and rupture (as well as the composite reintervention/open conversion/rupture; log-rank P < 0.001 for all). Further, patients receiving exclusively DUS after their first postoperative year had better overall survival (log-rank P < 0.001). These outcome advantages that were associated with DUS-only surveillance compared with CT/MRI-only surveillance after EVAR persisted when controlling for baseline covariates, preoperative AAA diameter, prior aortic surgery history, sac growth, and presence of endoleak (all P < 0.01).

CONCLUSIONS

EVAR patients selected for DUS-only surveillance after the first postoperative year have excellent freedom from AAA-related reintervention, conversion to open repair, rupture and all-cause mortality. These findings remained on multivariable analysis after adjusting for baseline characteristics, endoleak status and sac diameter changes within the first year. This is the first registry-based investigation to document long-term EVAR outcomes for patients entered into a DUS-only monitoring protocol which serves to corroborate the growing evidence base that DUS may be able to supplant CT surveillance in certain subgroups. A prospective randomized multicenter trial comparing DUS versus CT-based imaging after EVAR is needed to validate these findings which may serve to change current practice guidelines, as well as industry and regulatory stakeholder requirements.

A procedural step analysis of radiation exposure in fenestrated endovascular aortic repair

OBJECTIVE

Radiation exposure during complex endovascular aortic repair may be associated with tangible adverse effects in patients and operators. This study aimed to identify the steps of highest radiation exposure during fenestrated endovascular aortic repair (FEVAR) and to investigate potential intraoperative factors affecting radiation exposure.

METHODS

Prospective data of 31 consecutive patients managed exclusively with four-fenestration endografts between March 1, 2020, and July 1, 2022 were retrospectively analyzed. Leveraging the conformity of the applied technique, every FEVAR operation was considered a combination of six overall stages composed of 28 standardized steps. Intraoperative parameters, including air kerma, dose area product, fluoroscopy time, and number of digital subtraction angiographies (DSAs) and average angulations were collected and analyzed for each step.

RESULTS

The mean procedure duration and fluoroscopy time was 140 minutes (standard deviation [SD], 32 minutes), and 40 minutes (SD, 9.1 minutes), respectively. The mean air kerma was 814 mGy (SD, 498 mGy), and the mean dose area product was 66.8 Gy cm2 (SD, 33 Gy cm2). The percentage of air kerma of the entire procedure was distributed throughout the following procedure stages: preparation (13.9%), main body (9.6%), target vessel cannulation (27.8%), stent deployment (29.1%), distal aortoiliac grafting (14.3%), and completion (5.3%). DSAs represented 23.0% of the total air kerma. Target vessel cannulation and stent deployment presented the highest mean lateral angulation (67 and 63 degrees, respectively). Using linear regression, each minute of continuous fluoroscopy added 18.9 mGy of air kerma (95% confidence interval, 17.6-20.2 mGy), and each DSA series added 21.1 mGy of air kerma (95% confidence interval, 17.9-24.3 mGy). Body mass index and lateral angulation were significantly associated with increased air kerma (P < .001).

CONCLUSIONS

Cannulation of target vessels and bridging stent deployment are the steps requiring the highest radiation exposure during FEVAR cases. Optimized operator protection during these steps is mandatory.

Individualizing Surveillance after Endovascular Aortic Repair Using a Modular Imaging Algorithm

OBJECTIVES

Surveillance after endovascular aortic repair (EVAR) and fenestrated EVAR (FEVAR) is mainly directed by one-size-fits-all approaches instead of personalized decision making, even though treatment strategies and often endografts themselves are tailor-made to adjust for individual patients. We propose a modular imaging algorithm that escalates surveillance imaging based on invasiveness and need.

MATERIALS AND METHODS

In this retrospective observational study of single-center data, results of a modular imaging algorithm were analyzed. The algorithm is characterized by initiating the examination with standard B-mode then transitioning to Duplex ultrasound, B-Flow, and CEUS. Additional CT(A) studies are conducted where required. The study population included both patients receiving EVAR or FEVAR. A comparative analysis was conducted regarding endoleak detection.

RESULTS

The study population included 28 patients receiving EVAR and 40 patients receiving FEVAR. They accounted for 101 follow-up visits, which led to 431 distinct imaging studies. CEUS has the highest endoleak detection rate, followed by CTA and B-Flow. Duplex ultrasound and B-Flow resulted in 0 and 1 false positive cases, respectively, considering CEUS the reference standard. In a select group of six patients, CEUS was omitted after endoleaks were displayed by Duplex ultrasound or B-Flow, leading to a successful type II coiling and no aneurysm-related adverse events.

CONCLUSIONS

The proposed modular algorithm showed great potential to incorporate principles of personalized medicine in surveillance after endovascular aortic treatment. Since Duplex ultrasound and B-Flow rarely cause false positive endoleaks, more resource-intensive and invasive imaging studies such as CEUS and CTA can be omitted after positive identification.

Ultrasound Surveillance is Feasible After Endovascular Aneurysm Repair

BACKGROUND

Surveillance after endovascular aneurysm repair (EVAR) is traditionally done with computed tomography angiography (CTA) scans that exposes patient to radiation, nephrotoxic contrast media, and potentially increased risk for cancer. Ultrasound (US) is less labor intensive and expensive and might thus provide a good alternative for CTA surveillance. The aim of this study was to evaluate in real-life patient cohorts whether US is able to detect post-EVAR aneurysm-related complications similarly to CTA.

METHODS

This retrospective study compared the outcome of consecutive patients who underwent EVAR for intact abdominal aortic aneurysm and were surveilled solely by CTA (CTA-only cohort, n = 168) in 2000-2010 or by combined CTA and US (CTA/US cohort, n = 300) in 2011-2016, as a standard surveillance protocol in the department of vascular surgery, Helsinki University Hospital. The CTA-only patients were imaged at 1, 3, and 12 months and annually thereafter. The CTA/US patients were imaged with CTA at 3 and 12 months, US at 6 months and annually thereafter. If there were suspicion of >5 mm aneurysm growth, CTA scan was performed. The patients were reviewed for imaging data, reinterventions, aneurysm ruptures, and death until December 2018. The 2 groups were compared for secondary rupture, aneurysm-related and cancer-related death, reintervention related to abdominal aortic aneurysm, and maximum aneurysm diameter increase ≥5 mm. The mean follow-up in the CTA-only cohort was 67 months and in CTA/US cohort 43 months.

RESULTS

The 2 cohorts were alike for basic characteristics and for the mean aneurysm diameter. The total number of CT scans for detecting aneurysm was 84.1/100 patient years in the CTA-only cohort compared to 74.5/100 patient years for US/CTA cohort. Forty percent of patients under combined CTA/US surveillance received 1 or more additional CTA scans. The 2 cohorts did not differ for 1-year, 5-year and 8-year freedom from aneurysm related death, secondary sac rupture, nor the incidence of rupture preventing interventions.

CONCLUSIONS

Based on the follow-up data of this real-life cohort of 468 patients, combined surveillance with US and additional CTA either per protocol or due to suspicion of aneurysm-related complications had comparable outcome with sole CTA-surveillance. Thus, US can be considered a reasonable alternative for the CTA. However, our study showed also that the need of additional CTAs due to suspicion of endoleak or aneurysm nonrelated reasons is substantial.

Patients' Radiation Exposure During Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

To investigate associations between patient characteristics, intraprocedural complexity factors, and radiation exposure to patients during endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

Elective standard EVAR procedures between January 2015 and December 2020 were retrospectively analyzed. Patient characteristics and intraprocedural data (i.e., type of device, endograft configuration, additional procedures, and contralateral gate cannulation time [CGCT]) were collected. Dose area product (DAP) and fluoroscopy time were considered as measurements of radiation exposure. Furthermore, effective dose (ED) and doses to internal organs were calculated using PCXMC 2.0 software. Descriptive statistics, univariable, and multivariable linear regression were applied to investigate predictors of increased radiation exposure.

RESULTS

The 99 patients were mostly male (90.9%) with a mean age of 74 ± 7 years. EVAR indications were most frequently abdominal aortic aneurysm (93.9%), penetrating aortic ulceration (2.0%), focal dissection (2.0%), or subacute rupture of infrarenal abdominal aortic aneurysm (2.0%). Median fluoroscopy time was 19.6 minutes (interquartile range [IQR], 14.1-29.4) and median DAP was 86,311 mGy cm2 (IQR, 60,160-130,385). Median ED was 23.2 mSv (IQR, 17.0-34.8) for 93 patients (93.9%). DAP and ED were positively correlated with body mass index (BMI) and CGCT. Kidneys, small intestine, active bone marrow, colon, and stomach were the organs that received the highest equivalent doses during EVAR. Higher DAP and ED values were observed using the Excluder endograft, other bi- and tri-modular endografts, and EVAR with ≥2 additional procedures. Multivariable linear regression analysis revealed that BMI, ≥2 additional procedures during EVAR, and CGCT were independent positive predictors of DAP and ED levels after accounting for endograft type.

CONCLUSIONS

Patient-related and procedure-related factors such as BMI, ≥2 additional procedures during EVAR, and CGCT resulted predictors of radiation exposure for patients undergoing EVAR, as quantified by higher DAP and ED levels. The main intraprocedural factor that increased radiation exposure was CGCT. These data can be of importance for better managing radiation exposure during 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.

Endoleak Detection after Endovascular Aortic Repair via Coded-Excitation Ultrasound-A Feasibility Study

Endoleaks are the most common complication after endovascular aortic repair (EVAR). Their correct identification is one of the main objectives of surveillance protocols after EVAR. So far, computed tomography angiography (CTA), contrast-enhanced (CEUS) and Duplex ultrasound (DUS), as well as magnetic resonance angiography, have been investigated for their ability to detect endoleaks. In general, all technologies have distinct benefits and disadvantages, with CTA and CEUS emerging as the reference standard for surveillance after EVAR. However, they are both contrast-enhancer-dependent, and CTA additionally exposes patients to ionizing radiation. In the present study, we investigated B-Flow, a type of coded-excitation ultrasound that was specifically designed to optimize the visualization of blood flow, for its ability to detect endoleaks, and compared its performance to CEUS, CTA, and DUS. In total, 34 patients were included in the analysis that accumulated in 43 distinct B-Flow investigations. They underwent a total of 132 imaging investigations. Agreement between B-Flow and other imaging modalities was high (>80.0%), while inter-method reliability can be interpreted as good. However, with B-Flow, six and one endoleaks would have been missed compared to CEUS and CTA, respectively. Regarding endoleak classification, all metrics were lower but retained an adequate level of comparison. In a subset of patients requiring intervention, B-Flow had 100% accuracy regarding both endoleak detection and classification. Ultrasonography enables endoleak detection and classification without the need for pharmaceutical contrast enhancement or radiation. Ultrasound coded-excitation imaging in the application of B-Flow could further simplify surveillance after EVAR by offering adequate accuracy without requiring intravenous contrast enhancement. Our findings may promote subsequent investigations of coded-excitation imaging for endoleak detection and classification in the surveillance after EVAR.

Imaging and Surveillance of Chronic Aortic Dissection: A Scientific Statement From the American Heart Association

All patients surviving an acute aortic dissection require continued lifelong surveillance of their diseased aorta. Late complications, driven predominantly by chronic false lumen degeneration and aneurysm formation, often require surgical, endovascular, or hybrid interventions to treat or prevent aortic rupture. Imaging plays a central role in the medical decision-making of patients with chronic aortic dissection. Accurate aortic diameter measurements and rigorous, systematic documentation of diameter changes over time with different imaging equipment and modalities pose a range of practical challenges in these complex patients. Currently, no guidelines or recommendations for imaging surveillance in patients with chronic aortic dissection exist. In this document, we present state-of-the-art imaging and measurement techniques for patients with chronic aortic dissection and clarify the need for standardized measurements and reporting for lifelong surveillance. We also examine the emerging role of imaging and computer simulations to predict aortic false lumen degeneration, remodeling, and biomechanical failure from morphological and hemodynamic features. These insights may improve risk stratification, individualize contemporary treatment options, and potentially aid in the conception of novel treatment strategies in the future.

Survival and cause of death after aortic arch aneurysm repair

BACKGROUND

This study aimed to identify differences in prognosis, causes of death, and outcomes between open and endovascular repair for aortic arch aneurysms.

METHODS

We retrospectively analyzed the survival status and causes of death determined from the medical records of 124 consecutive elderly patients (age>70 years) with aortic arch aneurysms that were treated between 2010 and 2018 at our hospital. Forty patients (male, N.=30; mean age, 76 years) underwent open repair and 84 (male, N.=68; mean age, 78 years) underwent endovascular repair.

RESULTS

Early postoperative complications (10.0% vs. 6.3%; P=0.4) and rates of in-hospital death (2.5% vs. 6.3%; P=0.2) did not significantly differ between open and endovascular repair. Cumulative long-term and event free survival rates at eight years were similar in both groups (78.7% vs. 66.3%, P=0.1 and 66.6% vs. 58.4%; P=0.4, respectively). The causes of death at follow-up after endovascular repair comprised malignancies in 11 (52.4%) patients and cardiopulmonary and cerebral events unrelated to aortic aneurysms in 10 (47.6%).

CONCLUSIONS

Early and late outcomes did not statistically differ after both procedures. However, the prevalence of cancer-related death occurring late after arch repair was significantly higher after endovascular repair. The most important observation from this series was that significantly more patients died of malignant disease during follow-up after endovascular repair than open repair.

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.

Late-Onset Malignant Neoplasms and Their Prognostic Factors after Abdominal Aortic Aneurysm Repair

BACKGROUND

Little is known about late-onset primary malignant neoplasms after repair of abdominal aortic aneurysms (AAAs) despite malignancy being one of the primary causes of late death. We investigated the incidence and prognostic factors related to the occurrence of malignancy after AAA repair.

METHODS

We performed a retrospective analysis of 589 patients who underwent AAA repair, including 264 endovascular AAA repairs and 325 open surgical repairs; 482 patients had no history of previous malignancy or concomitant malignancy, 72 had previous malignancy, and 35 had concomitant malignancy in remission at the time of AAA repair. The cumulative incidence rates of late-onset malignancy occurrence and cancer death were estimated using the cumulative incidence function in the presence of competing risks, that is, noncancer death, and prognostic factors were investigated using the Fine-Gray hazard model.

RESULTS

After hospital discharge, 128 malignancies occurred in 116 patients. Overall cumulative incidence rates of late-onset malignancy occurrence at 1, 3, 5, and 10 years were 4.0%, 11.7%, 18.2%, and 38.1%, respectively. Multivariate analysis revealed that significant prognostic factors for late-onset malignancy included history of previous malignancy, current smoker, higher intraoperative blood loss, absence of allogeneic blood transfusion, lower C-reactive protein levels, and lower serum high-density lipoprotein-cholesterol levels. The type of surgical procedures for AAA repair did not affect the occurrence of malignancy. In addition, current smoker and higher intraoperative blood loss significantly increased the risk of cancer death.

CONCLUSIONS

Current smoker and higher intraoperative blood loss were independent risk factors for late-onset malignancy after AAA repair. Late-onset malignancy after AAA repair should be monitored among patients at high risk and requires aggressive management to improve long-term survival.

Identifying and addressing the limitations of EVAR technology

INTRODUCTION

Endovascular aortic repair (EVAR) has improved over the last two decades. Approximately 80% of the patients presenting with an abdominal aortic aneurysm (AAA) is nowadays primarily treated with EVAR.

AREAS COVERED

In this review, the differences between endovascular and open repair, the clinical characteristics needed for EVAR, the role of clinical imaging and the developments in EVAR technology will be discussed. Early mortality is lower in EVAR as compared to open repair, whereas this benefit is lost after 3 years postoperatively. EVAR comes with a high reintervention rate, with endoleak being the most important predictive factor for reintervention. Expanding technical possibilities have allowed surgeons to choose from a palate of endovascular approaches in aneurysm patients with challenging anatomies.

EXPERT COMMENTARY

Although EVAR has taken a giant leap forward in development, the new developments have seemed to surpass the long-term limitations with older devices. It is important to start focusing on the current limitations of EVAR, in particular the durability of devices in the human variable anatomic and dynamic environment.

Angiossarcoma mimetizando endoleak tardio pós-reparo endovascular de aneurisma de aorta infrarrenal: relato de caso

Resumo Em todo paciente submetido a reparo endovascular do aneurisma de aorta abdominal (REVA) que se apresente subitamente com quadro de dor abdominal ou sinais de choque, a hipótese de endoleak ou vazamento, com expansão do aneurisma e ruptura deve ser aventada. Apresentamos o caso de um paciente em pós-operatório de REVA que apresentou uma neoplasia de duodeno mimetizando um endoleak.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Incidental extravascular findings in computed tomographic angiography for planning or monitoring endovascular aortic aneurysm repair: Smoker patients, increased lung cancer prevalence?

AIM

To validate the feasibility of high resolution computed tomography (HRCT) of the lung prior to computed tomography angiography (CTA) in assessing incidental thoracic findings during endovascular aortic aneurysm repair (EVAR) planning or follow-up.

METHODS

We conducted a retrospective study among 181 patients (143 men, mean age 71 years, range 50-94) referred to our centre for CTA EVAR planning or follow-up. HRCT and CTA were performed before or after 1 or 12 mo respectively to EVAR in all patients. All HRCT examinations were reviewed by two radiologists with 15 and 8 years’ experience in thoracic imaging. The results were compared with histology, bronchoscopy or follow-up HRCT in 12, 8 and 82 nodules respectively.

RESULTS

There were a total of 102 suspected nodules in 92 HRCT examinations, with a mean of 1.79 nodules per patient and an average diameter of 9.2 mm (range 4-56 mm). Eighty-nine out of 181 HRCTs resulted negative for the presence of suspected nodules with a mean smoking history of 10 pack-years (p-y, range 5-18 p-y). Eighty-two out of 102 (76.4%) of the nodules met criteria for computed tomography follow-up, to exclude the malignant evolution. Of the remaining 20 nodules, 10 out of 20 (50%) nodules, suspected for malignancy, underwent biopsy and then surgical intervention that confirmed the neoplastic nature: 4 (20%) adenocarcinomas, 4 (20%) squamous cell carcinomas, 1 (5%) small cell lung cancer and 1 (5%) breast cancer metastasis); 8 out of 20 (40%) underwent bronchoscopy (8 pneumonia) and 2 out of 20 (10%) underwent biopsy with the diagnosis of sarcoidosis.

CONCLUSION

HRCT in EVAR planning and follow-up allows to correctly identify patients requiring additional treatments, especially in case of lung cancer.

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 versus open repair of abdominal aortic aneurysm in 15-years' follow-up of the UK endovascular aneurysm repair trial 1 (EVAR trial 1): a randomised controlled trial

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) versus open repair of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is lost after a few years. We investigated whether EVAR had a long-term survival benefit compared with open repair.

METHODS

We used data from the EVAR randomised controlled trial (EVAR trial 1), which enrolled 1252 patients from 37 centres in the UK between Sept 1, 1999, and Aug 31, 2004. Patients had to be aged 60 years or older, have aneurysms of at least 5·5 cm in diameter, and deemed suitable and fit for either EVAR or open repair. Eligible patients were randomly assigned (1:1) using computer-generated sequences of randomly permuted blocks stratified by centre to receive either EVAR (n=626) or open repair (n=626). Patients and treating clinicians were aware of group assignments, no masking was used. The primary analysis compared total and aneurysm-related deaths in groups until mid-2015 in the intention-to-treat population. This trial is registered at ISRCTN (ISRCTN55703451).

FINDINGS

We recruited 1252 patients between Sept 1, 1999, and Aug 31, 2004. 25 patients (four for mortality outcome) were lost to follow-up by June 30, 2015. Over a mean of 12·7 years (SD 1·5; maximum 15·8 years) of follow-up, we recorded 9·3 deaths per 100 person-years in the EVAR group and 8·9 deaths per 100 person-years in the open-repair group (adjusted hazard ratio [HR] 1·11, 95% CI 0·97-1·27, p=0·14). At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0·61, 95% CI 0·37-1·02 for total mortality; and 0·47, 0·23-0·93 for aneurysm-related mortality, p=0·031), but beyond 8 years of follow-up open-repair had a significantly lower mortality (adjusted HR 1·25, 95% CI 1·00-1·56, p=0·048 for total mortality; and 5·82, 1·64-20·65, p=0·0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture (13 deaths [7%] in EVAR vs two [1%] in open repair), with increased cancer mortality also observed in the EVAR group.

INTERPRETATION

EVAR has an early survival benefit but an inferior late survival compared with open repair, which needs to be addressed by lifelong surveillance of EVAR and re-intervention if necessary.

FUNDING

UK National Institute for Health Research, Camelia Botnar Arterial Research Foundation.

Cumulative radiation dose and radiation risk from medical imaging in patients subjected to endovascular aortic aneurysm repair

PURPOSE

This study was undertaken to quantify the cumulative effective dose (CED) of radiation and the dose to relevant organs in endovascular aortic repair (EVAR) patients, to assess radiation risks and to evaluate the clinical usefulness of multi-detector computed tomography (MDCT) follow-up.

MATERIALS AND METHODS

The radiation exposures were obtained from 71 consecutive EVAR patients with a follow-up duration ≥1 year. Dose calculations were performed on an individual basis and expressed as effective doses and organ doses. Radiation risk was expressed as risk of exposure-induced death (%), using the biological effects of ionising radiation model. Two radiologists independently assessed the images for abdominal aortic aneurysm expansion without endoleaks, thrombotic occlusion, endoleaks and device migration. They first reviewed arterial imaging alone and subsequently added non-contrast and delayed phases to determine the overall performance.

RESULTS

The median total CED and annual CED were 224 and 104 mSv per patient-year. The median cumulative organ doses were 191, 205, 230, 269 and 271 mSv for lung, bone marrow, liver, colon and stomach, respectively. The average risk of exposure-induced death was 0.8 % (i.e., odds 1 in 130). All the findings related to EVAR outcome and leading to a change in patient management were visible during the arterial phase of the MDCT angiography. Omission of the unenhanced scan and the venous phase of the MDCT angiography would have led to a significant reduction of about 60 % of the associated MDCT radiation exposure in a single patient.

CONCLUSIONS

EVAR patients received high radiation doses and the excess cancer risk attributable to radiation exposure is not negligible. The unenhanced scan and the venous phase of the MDCT angiography could have been omitted without compromising the utility of the examination and with a significant reduction of doses and associated risks.

Contemporary outcomes of open repair of thoracoabdominal aortic aneurysm in young patients

Background

Endovascular technology now permits total endovascular thoracoabdominal aortic aneurysm (TAAA) repair with high volume centres reporting encouraging results. The long-term durability of such stent grafts is unknown, leading to concerns regarding their use in younger patients. This study reports contemporary outcomes of open repair in young patients.

Methods

Outcomes for patients age 60 or younger undergoing open TAAA repair between June 1999 and August 2013 with prospective collected data were analysed retrospectively.

Results

Thirty-seven patients (31 men, 84%) with a median age of 56 (range 22–60) were identified with a median TAAA diameter of 6.9 cm (range 5.6-11). Aneurysm aetiology included degenerative change (18), dilation of chronic dissection (10), connective tissue disease (7) and mycotic degeneration (2). Crawford Type IV TAAA were most commonly treated (17), followed by Type II (10), Type III (7) and Type I (3). Two (5%) patients died in hospital, one from multiple organ failure and one from respiratory failure. Three patients (8%) developed temporary paraplegia, all of whom made a complete recovery and 4 (11%) patients required temporary renal replacement therapy. Median critical care stay was 5 days (range 2–28) with an in-hospital stay of 14 days (range 7–83). During a median follow-up of 72 months (range 13–171), no patient subsequently required any further aneurysm related surgical or radiological intervention. The mean (SEM) survival time was 138.5 (11) months. The 5 year survival was 79.7% (8.3) including early deaths, with no aneurysm related complications.

Conclusions

The outcome of open TAAA repair in patients aged less than 60 years is favorable. It is against these results that evolving endovascular interventions must be compared.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0195-4) contains supplementary material, which is available to authorized users.

Review of the Use of Ionizing Radiation in Endovascular Aneurysm Repair

Endovascular repair for aortic aneurysm (EVAR) is rapidly increasing in popularity. The nature of this intervention requires significant exposure to ionizing radiation both during the procedure and for postoperative surveillance, generally in the form of computed tomography. Here the authors review the literature for radiation exposure during EVAR, both for the patient and the physician.

Radiation exposure among patients with the highest CT scan utilization in the emergency department

The risk of cancer from computed tomography (CT) scan radiation is a rising concern in the medical field. Our objectives were to determine how many patients received more than ten CT scans in an academic emergency department (ED) over the course of 7 years and to quantify their radiation exposure and lifetime attributable risk of cancer. An electronic chart review was performed at our urban academic institution with an annual census of 110,000 patients. All patients who underwent a CT scan performed during ED management between the dates of January 2001 and December 2007 were identified. Specific predetermined data elements (e.g., subject demographics, type of CT scan) were extracted by two researchers blinded to hypothesis, using a preformatted data form. After identifying patients with more than ten CTs performed during the study period, radiation exposure was calculated based on accepted and reported radiation doses for the respective anatomic CTs, and lifetime attributable cancer risk was calculated based on the seventh report of the Biological Effects of Ionizing Radiation (BEIR VII) projections. Over the 7-year study period, 24,393 patients received 34,671 CT scans. The vast majority of patients (17,909) received a single CT. Twenty-six (0.1 %) patients received more than ten CTs totaling 374 scans with an average radiation exposure of 83.4 mSv. The maximum lifetime attributable risk for any individual in this cohort was 1.7 % above the baseline cancer risk. Among those undergoing CT imaging in our ED, high-exposure patients (greater than ten scans) constituted a significant minority, while more than one in four patients underwent more than one CT scan during the study period. While the presumed overall risk of radiation-induced cancer continues to be low, it is important for the emergency physician to use clinical knowledge as well as concern for the patient when utilizing radiographic imaging. Increasing attributable cancer risk may have important public health implications in the future, regardless of the low individual risk.