Endovascular Aortic Aneurysm Repair Patients Research Articles

The association between device instructions for use adherence and outcomes after elective endovascular aortic abdominal aneurysm repair

ObjectiveAortic neck anatomy has a significant impact on the complexity of endovascular aortic aneurysm repair (EVAR), with concern that neck characteristics outside of the instructions for use (IFU) may result in worse outcomes. Therefore, this study determined the impact of neck characteristics outside of the IFU on perioperative and 1-year outcomes and mid-term survival after EVAR. MethodsWe identified all patients undergoing elective infrarenal EVAR from December 2014 to May 2020 in the Vascular Quality Initiative database. Neck characteristics outside of the IFU were determined based the specific device IFU neck characteristics (neck diameter, length, and angulation). Patients without 1-year follow-up were excluded for the 1-year outcomes analyses (n = 6138 [40%]). We used multivariable adjusted logistic regression and Cox proportional hazard models to identify the independent associations between neck characteristics outside of the IFU and our outcomes. ResultsOf the 15,448 patients identified, 22.1% had neck characteristics outside of the IFU, including 6.6% with a infrarenal angle, 6.8% with a neck length, 10.4% with a neck diameter, and 1.1% with a suprarenal angulation outside of the IFU. Of these, 2.4% had more than one neck characteristic outside of the IFU. Patients with neck characteristics outside of the IFU were more often female (27.9% vs 15.0%; P < .001) and were older (median age, 75 years vs 73 years; P < .001). EVAR patients with neck characteristics outside of the IFU had higher rates of type Ia endoleaks at completion (4.8% vs 2.5%; P < .001), perioperative mortality (1.2% vs 0.6%; P < .001), 1-year sac expansion (7.1% vs 5.3%; P = .017), and 1-year reinterventions (4.4% vs 3.2%; P = .03). In multivariable adjusted analyses, neck characteristics outside of the IFU were independently associated with type Ia completion endoleaks (OR, 1.6; 95% CI, 1.3-2.0; P < .001), perioperative mortality (OR, 1.8; 95% CI, 1.2-2.7; P = .005), 1-year sac expansion (OR, 1.4; 95% CI, 1.0-1.8; P = .025), and 1-year reinterventions (OR, 1.4; 95% CI, 1.0-1.9; P = .039). The unadjusted midterm survival was lower for patients with neck characteristics outside of the IFU than for patients without (5-year survival 84.0% vs 86.7%; log-rank P < .001). However, after adjustment, survival was similar for patients with neck characteristics outside of the IFU to those within (hazard ratio, 1.1; 95% CI, 1.0-1.3; P = .22). ConclusionsNeck characteristics outside of the IFU are independently associated with completion type Ia endoleaks, perioperative mortality, 1-year sac expansion, and 1-year reinterventions among patients undergoing elective EVAR. These results indicate that continued effort is needed to improve the proximal seal in patients with neck characteristics outside of the IFU undergoing EVAR. Also, in patients with severe hostile neck characteristics, alternative approaches such as open repair, use of a fenestrated or branched device, or endoanchors should be considered.

Editor's Choice – A Comparison of Computed Tomography Angiography and Colour Duplex Ultrasound Surveillance Post Infrarenal Endovascular Aortic Aneurysm Repair: Financial Implications and Impact of Different International Surveillance Guidelines

Use of colour duplex ultrasound (CDUS) and computed tomography angiography (CTA) for infrarenal endovascular aortic aneurysm repair (EVAR) surveillance differs in internationally published guidelines. This study aimed firstly to compare CDUS detection of significant sac abnormalities with CTA. Secondly, a sensitivity analysis was conducted to compare financial estimates of the, predominantly CDUS based, local and Society of Vascular Surgery (SVS) protocols, the risk stratified European Society of Vascular Surgery (ESVS) protocol, and the CTA based National Institute of Health and Care Excellence (NICE) protocol. Agreement between CDUS and CTA was assessed for detection of significant sac abnormalities. Surveillance protocols were extrapolated from published guidelines and applied to infrarenal EVAR patients active on local surveillance at a large, single centre. Surveillance intensity was dependent on presence of endoleak and subsequent risk of treatment failure in accordance with surveillance recommendations. Estimates for each surveillance protocol were inclusive of a range of published incidences of endoleak, contrast associated acute kidney injury (AKI), and excess hospital bed days, and estimated for a hypothetical five year surveillance period. The kappa coefficient between CDUS and CTA for detecting sac abnormalities was 0.68. Maximum five year surveillance cost estimates for the 289 active EVAR patients were £272 359 for SVS, £230 708 for ESVS, £643 802 for NICE, and £266 777 for local protocols, or £1 270, £1 076, £3 003, and £1 244 per patient. Differences in endoleak incidence accounted for a 1.1 to 1.4 fold increase in costs. AKI incidence accounted for a 3.3 to 6.2 fold increase in costs. A combined CTA and CDUS EVAR surveillance protocol, with CTA reserved for early seal assessment and confirmatory purposes, provides an economical approach without compromising detection of sac abnormalities. AKI, as opposed to direct imaging costs, accounted for the largest differences in surveillance cost estimates.

Incidence and predictors of early and delayed renal function decline after aortic aneurysm repair in the Vascular Quality Initiative database

BackgroundPostoperative acute kidney injury (AKI) may complicate both open and endovascular aortic aneurysm repair (EVAR) and is associated with substantial morbidity, mortality, and health care expense. We aim to evaluate the incidence of postoperative AKI and factors associated with its occurrence and the effects of postoperative AKI on long-term renal function and mortality after open and EVAR in the Society for Vascular Surgery Vascular Quality Initiative registry. MethodsElective aneurysm cases were identified including thoracic endovascular aortic aneurysm repair (TEVAR) and complex endovascular aortic aneurysm repair (cEVAR), infrarenal endovascular repair (EVAR) and infrarenal open repair (OAR) from 2003 to 2019. The preoperative estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease formula and stratified based on chronic kidney disease (CKD) grades. Postoperative AKI was defined per the Vascular Quality Initiative definition as a creatinine increase of 0.5 mg/dL or if postoperative dialysis was required. Patients on preprocedural hemodialysis and those with previous renal transplant were excluded. Demographics and procedural factors were evaluated for predicting in-hospital postoperative AKI (all approaches) and at 9 to 21 months of long-term follow-up (EVAR only) using logistic regression modeling. ResultsWe identified a total of 2813 cEVAR, 2995 TEVAR, 39,945 EVAR, and 8143 OAR patients. Of those, postoperative AKI occurred in 377 cEVAR (13.5%), 199 TEVAR (6.7%), 1099 EVAR (2.8%), and 1249 OAR (15.5%). Risk factors for postoperative AKI across all groups were worse preoperative eGFR, total number of blood transfusions, perioperative anemia, reinterventions, and postoperative respiratory complications. Additional procedure-specific risk factors of postoperative AKI were preoperative hemoglobin of less than 10 and contrast volume of 125 to 150 mL, hypertension, a low ejection fraction, and a history of percutaneous revascularization for EVAR; for both EVAR/cEVAR, renal artery coverage was a risk factor, whereas for OAR, male sex, non-White race, hypertension, suprarenal aortic cross-clamp, and increased renal ischemic time were risk factors. Among 8133 EVAR patients with long-term follow-up, a decrease in kidney function occurred in 56.7% of patients with postoperative AKI vs 19.9% without postoperative AKI (P < .001). The following risk factors were associated with a decrease in renal function at long-term follow-up: postoperative AKI, a preoperative eGFR of less than 90, and hypertension. A preoperative hemoglobin of greater than 12 was protective. Postoperative AKI was associated with significantly lower survival compared with no postoperative AKI across all procedures (log rank <0.001). ConclusionsPostoperative AKI occurs more often in patients with worse preoperative renal function, lower preoperative hemoglobin, and in open surgeries with inter-renal or suprarenal cross-clamping. Importantly, postoperative AKI is associated with increased mortality across all types of aortic repair. Given the long-term impact of postoperative AKI on outcomes for all aortic repairs and the limitations of current insensitive functional indices, there is a need to seek more sensitive indicators of decreases in early renal structural in this population.

Detection of Late Complications After Endovascular Abdominal Aortic Aneurysm Repair and Implications for Follow up Based on Retrospective Assessment of a Two Centre Cohort

Endovascular aortic aneurysm repair (EVAR) is associated with the risk of late complications and mandates follow up. This retrospective study assessed post-EVAR complications in a two centre cohort. The study evaluated the rate of complications presenting with symptoms vs. those detected by imaging follow up. Additionally, the agreement between DUS and CTA in detecting complications was assessed in patients with both. All EVAR patients from 1998 to 2012 in two centres were included. Complications were classified based on whether they were symptomatic or detected by imaging, as well as based on imaging detection modality (DUS or CTA). For patients who had undergone DUS and CTA within three months of each other, the kappa coefficient of agreement was assessed. Four hundred and fifty-four patients treated by EVAR were identified. The median follow up time was 5.2 (IQR 2.8–7.6) years. One hundred and eighteen patients (26%) developed 176 complications. One hundred and six (60.2%) of the complications were asymptomatic, and 70 (39.8%) were symptomatic. Two hundred and fifty-three patients had imaging with both modalities within three months of each other; the kappa coefficient for agreement between CTA and DUS for detecting clinically significant complications was 0.91. Regarding CTA as the standard modality, DUS had a sensitivity of 88.8% (95% CI 77.3–95.8%) and a specificity of 99.4% (95% CI 97.1–99.9%). Three of the complications missed by DUS were related to loss of proximal and distal seal, all occurring in patients with short sealing length on first post-operative CT scan. Approximately a quarter of the patients developed complications, the majority of which were asymptomatic, underlining the importance of adequate surveillance. There was good agreement between CTA and DUS in detecting complications. Clinically significant complications related to inadequate seal were missed by DUS, suggesting that CTA still plays an important role in EVAR surveillance.

Editor's Choice – Detection of Late Complications After Endovascular Abdominal Aortic Aneurysm Repair and Implications for Follow up Based on Retrospective Assessment of a Two Centre Cohort

Endovascular aortic aneurysm repair (EVAR) is associated with the risk of late complications and mandates follow up. This retrospective study assessed post-EVAR complications in a two centre cohort. The study evaluated the rate of complications presenting with symptoms vs. those detected by imaging follow up. Additionally, the agreement between DUS and CTA in detecting complications was assessed in patients with both. All EVAR patients from 1998 to 2012 in two centres were included. Complications were classified based on whether they were symptomatic or detected by imaging, as well as based on imaging detection modality (DUS or CTA). For patients who had undergone DUS and CTA within three months of each other, the kappa coefficient of agreement was assessed. Four hundred and fifty-four patients treated by EVAR were identified. The median follow up time was 5.2 (IQR 2.8-7.6) years. One hundred and eighteen patients (26%) developed 176 complications. One hundred and six (60.2%) of the complications were asymptomatic, and 70 (39.8%) were symptomatic. Two hundred and fifty-three patients had imaging with both modalities within three months of each other; the kappa coefficient for agreement between CTA and DUS for detecting clinically significant complications was 0.91. Regarding CTA as the standard modality, DUS had a sensitivity of 88.8% (95% CI 77.3-95.8%) and a specificity of 99.4% (95% CI 97.1-99.9%). Three of the complications missed by DUS were related to loss of proximal and distal seal, all occurring in patients with short sealing length on first post-operative CT scan. Approximately a quarter of the patients developed complications, the majority of which were asymptomatic, underlining the importance of adequate surveillance. There was good agreement between CTA and DUS in detecting complications. Clinically significant complications related to inadequate seal were missed by DUS, suggesting that CTA still plays an important role in EVAR surveillance.

Follow-Up after Endovascular Aortic Repair can be Stratified Based on First Postoperative Imaging

Introduction - Endovascular aortic aneurysm repair (EVAR) is now a day the standard method for treating abdominal aortic aneurysm (AAA). Surveillance to detect complications after EVAR, results in increasing costs, workload and patient dissatisfaction. We hypothesised that follow-up can be stratified based on the first postoperative computed tomography (CT). Methods - All EVAR-patients 2001-2012 in two Swedish centers were identified retrospectively. Patients were categorised based on the first postoperative CT into Low Risk (LR): proximal and distal sealing zone >=10mm and no endoleak, and High Risk (HR): sealing zone <10mm proximally or distally and/or presence of any endoleak. Follow-up imaging, AAA-related adverse events and re-interventions were registered. Logistic regression analysis was performed to assess predictors of AAA-related adverse events and AAA- related reinterventions; results are presented as the Odds ratio (OR) with 95% confidence interval (CI). Survival was analysed using the Kaplan-Meier method. Results - A total of 481 EVAR patients were identified, of which 347 (288 men) with a CT <1-year post-EVAR were included (LR n=224, HR n=123). There was no difference between the groups in gender, age, comorbidities, AAA-diameter, AAA-neck anatomy, stentgraft type or follow-up (median 4.7 years, range 0-14 years). In the HR group, 51% had short seal, and 67% endoleaks (50% type-II). Five-years freedom from AAA-related adverse events was LR 97%, HR 48%, p<0.001, and freedom from AAA-related re-intervention LR 97.5%, HR 53.5%, p<0.001. In a multivariable analysis, short sealing zone distally (Odds Ratio OR 62.642), proximally (OR 23.300) and type II endoleak (OR 9.235) were predictors for AAA-related adverse events, (p<0.001). The number of surveillance imaging per AAA-related adverse event was 176 in LR, versus 11 in HR during follow-up period. Conclusion - A majority of EVAR-patients have adequate seal and no endoleak on first postoperative CT, which is associated with a low risk for AAA-related events up to 5-years. These patients can safely be stratified to less vigilant follow-up early post-EVAR.

Suprarenal Aortic Remodeling after Endovascular Aortic Aneurysm Repair among Three Endografts with Different Types of Proximal Fixation System

Remodeling of suprarenal aorta after endovascular aortic aneurysm repair (EVAR) in relation to different endograft designs has not been thoroughly investigated. The aim of this study is to assess the anatomical configuration of the suprarenal aorta after using endografts with different proximal fixation during the first post-EVAR year. A retrospective study including EVAR patients using 3 types of endografts with different proximal fixation systems according to Instructions for Use was undertaken (50: Ovation, Endologix, Irvin, CA; 25: Endurant IIs, Medtronic, Santa Rosa, CA; 25: Excluder C3, W. L. Gore & Associates, Flagstaff, AZ). Comorbidities were recorded. Anatomic variables of the supra-aortic anatomy, abdominal aortic aneurysm (AAA) maximum diameter, and neck angulation were analyzed. Computed tomography angiography was obtained preoperatively at 1 and 12months post-EVAR, while a duplex scan was undertaken at 6months. Comorbidities were not different across the 3 groups. Presence and amount of neck calcification (P=0.139) and thrombus (P=0.116) was similar among groups. Maximum aortic diameter showed significant reduction from preoperative measurements to 12-month postoperative ones, for all groups. (Ovation: 56.5 to 53mm, P<0.001; Endurant: 57 to 51mm, P<0.001; Excluder: 55 to 50mm, P<0.001). Suprarenal angulation was decreased significantly in the Ovation (P<0.001) and Excluder groups (P=0.05), while the infrarenal angulation was decreased in all groups. Among endografts, the decrease in AAA maximum diameter was similar (P=0.99), while the suprarenal aortic diameter was significantly increased in Ovation patients in comparison to the other 2 endografts at the level of 5mm (P=0.02) and 25mm (P=0.01). Suprarenal angulation reduction was similar (P=0.7), while infrarenal angulation was significantly more decreased in Ovation endograft than the other 2 systems (P<0.001). Proximal endograft configuration appears to have different impact on supra-aortic anatomy. Longer follow-up is needed to clarify future remodeling and clinical impact of these observations.

PC018. Long-Term Outcomes Comparing Endovascular and Open Abdominal Aortic Aneurysm Repair in Octogenarians

Patients 80 years or older have significantly lower early mortality with endovascular aortic aneurysm repair (EVAR) when compared with open repair for abdominal aortic aneurysms (AAA). The long-term results in this older patient population remain poorly studied. We analyzed the results of emergent and elective AAA repair in patients 80 years or older who had at least 5 years of follow-up. A retrospective review of a prospectively collected vascular surgery database at a university-affiliated medical center was performed to identify all patients who underwent repair of an AAA between 2007 and 2012 and were 80 years of age or older at the time of surgery. Open and EVAR groups were compared for outcomes using univariate statistics. The study cohort comprised 314 patients (mean age, 83.5 ± 2.9 years) who underwent repair (96 open repair, 218 EVAR). Patients treated with open repair and EVAR had similar comorbidities, except that EVAR patients were more likely to be male, and open repair patients were more likely to have larger aneurysms. When compared with open repair, elective early postoperative mortality was significantly lower for EVAR patients (1% vs 14%; P < .001). Overall mean life expectancy was 5.9 years (5.8 years EVAR, 5.8 years open repair; P = .98). The 1-year survival was significantly higher for EVAR (92.9%) compared with open repair (84.1%; P = .02). Although 2-year survivals (83.4% EVAR, 74.6% open repair; P = .07), and 5-year survivals (57.8% EVAR, 60.3% open repair; P = .98) did not differ between EVAR and open repair (Fig 1). The most common causes of long-term mortality were malignant disease and cardiovascular events in both groups. Three patients (1.4%) initially treatment by endovascular intervention sustained a mortality related to their aneurysm, and no aneurysm-related mortalities occurred in the open group. Reintervention rates (14% EVAR, 2% open repair; P = .05) were higher in the endovascular treatment group (Fig 2). EVAR results in an improved 1-year mortality in octogenarians when compared with open repair, although 5-year survival is similar between the two groups. With average life expectancies over 5 years after surgery and a 14% reintervention rate, diligent follow-up is required after EVAR in these elderly patients.Fig 2Freedom from reintervention. Cum, Cumulative; EVAR, endovascular aortic aneurysm repair.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A Single-Institution Experience With Ruptured Aortic Aneurysms

With the continued advancement in aortic endografts and increasing surgeon experience, endovascular aortic aneurysm repair (EVAR) is now commonly used for ruptured abdominal aortic aneurysms (rAAAs). Although randomized controlled trials have shown improved short-term morbidity and mortality with EVAR compared to open repair in the elective setting, the data for rAAA remain scarce. This study reviewed the data on rAAA at our institution and compared outcomes of open repair vs EVAR. All patients admitted to the University of Iowa Hospitals and Clinics between 2008 and 2015 with rAAA were identified. Demographic and clinical characteristics of patients were described using simple summary statistics. The distance from the hospital and the patients’ mode of transportation were also included. Categoric and continuous variables were analyzed using SPSS 22 software (IBM, Armonk, NY). There were 86 patients admitted to our institution with rAAA. Four were managed by palliative care, and 82 underwent surgical repair. The average distance to the local hospital at presentation was 12.5 miles, with 62.8% transported by ground and 37.2% airlifted, with an average distance of 57.7 miles. An equal number of patients (n = 41) underwent open repair and EVAR. Open femoral access was used in 47.5% of those who underwent EVAR, and 52.5% had percutaneous access. The overall mortality rate was 9.3% at 24 hours and 27.5% at 30 days. When mortality at 30 days was evaluated, there was no statistically significant difference between mode of transportation, distance from the patient’s home to the local hospital, or open repair vs EVAR. Among EVAR patients, there was no difference in 30-day mortality between type of femoral access or type of anesthesia. The primary factors associated with increased mortality were older age and increased number of medical comorbidities. In patients with rAAA, mortality appears to be more related to their age and the number of medical comorbidities rather than to the type of repair or the proximity to the hospital at the time of rupture.

Elective Endovascular Aortic Aneurysm Repair Continues to Cost More than Open Abdominal Aortic Aneurysm Repair

Endovascular aortic aneurysm repair (EVAR) is now established as first-line treatment for infrarenal aortic aneurysms in the United States. Recent data from randomized trials suggest that elective EVAR is cost-effective compared with open abdominal aortic aneurysm repair (oAAA). Cost analysis for urgent aneurysm repair has not been reported. We evaluated the cost of elective and urgent EVAR and compared it with oAAA at a tertiary academic medical center. All infrarenal AAA repairs performed from 2004 to 2010 were retrospectively reviewed (n=172). Clinical characteristics of patients receiving EVAR and oAAA repair were compared. Direct costs, payments, and direct cost margin for the index inpatient episode were obtained from the hospital for all patients. Subsequent financial information including clinical, radiologic, and procedural cost was also available for 52 patients who had received all follow-up care in our institution for at least 1 year (EVAR 34, oAAA 18). Overall, elective EVAR patients were older, but oAAA patients had more comorbidities, with significantly more patients having dyspnea at rest and being totally dependent for activities of daily living. EVAR patients had significantly shorter lengths of stay, regardless of urgency and urgent AAA repair occurred more often by oAAA than EVAR (P<0.001; χ2). For elective patients, EVAR costs were 34.21% greater than for oAAA. There was a trend toward lower costs with EVAR versus oAAA in patients treated urgently by a ratio of 1.28:1. The hospital experienced a negative cost margin more often after elective EVAR versus oAAA. Negative cost margins were less frequent following urgent repair but still occurred twice as often in EVAR versus oAAA patients. Cost margins remained negative in all EVAR patients for at least 1 year and only 18% converted to a positive cost margin at a mean of 31months. At a tertiary academic institution, costs for elective EVAR are significantly higher than oAAA. EVAR may be relatively more cost-effective in urgent situations. Negative cost margins were more common in EVAR patients and 1-year follow-up with imaging in the same institution did not result in a positive margin.

Endograft Sizing for Endovascular Aortic Repair and Incidence of Endoleak Type 1A

ObjectiveIn endovascular aortic aneurysm repair (EVAR), proximal type 1A endoleaks can occur as a result of hostile neck anatomy or over- or undersizing of the endograft. As the current standard is based on the diameter or average of the short and long axes in a central lumen reconstruction image, it can falter in irregularly shaped aortic necks. An alternative method is circumference-based, therefore minimizing the measurement error. In this study we aimed to assess the degree of discrepancy between both methods and the association of this discrepancy with the occurrence of endoleak type 1A.MethodsAll patients with early (<30 days post-operative) endoleak type 1A after elective EVAR at our center between 2004 and 2016 were identified for a retrospective case-control study. Control patients were matched based on hostile neck anatomy, such as calcification, thrombus, reverse taper, and β-angulation. The aortic neck diameter was measured using the traditional, diameter-based method as well as an alternative method, based on the circumference of the aortic neck.ResultsIn 482 EVAR patients, 18 early endoleak type 1A cases were found (3.9%). After exclusion, 12 cases remained and 48 matching controls were found. No significant differences were found between the two measuring methods at any level below the renal arteries. The inter-observer variability was significant for the D(mean) (0.4 ± 1.69 mm, P = .02) and was larger than the D(circ) method (-0.1 ± 1.03 mm, P = .35). In only four out of 12 cases the endograft size was 10–20% larger than the D(mean) and D(circ) measurements. The differences between the diameter of the D(mean) and D(circ) and the chosen endograft were smaller for the case group (-8 ± 25.6% and -7 ± 24%) than for the control group. (-12.4 ± 12.4% and -11 ± 10.7%).ConclusionThe difference between the D(mean) and D(circ) methods for aortic neck measurement was not large enough to play a significant role in the incidence of endoleak type 1A. Inadequate oversizing and considerable β-angulation of the aortic neck may have been the cause of endoleak type 1A in this population. Robust and well-investigated sizing methods are paramount for accurate endograft sizing and prevention of endoleak type 1A. Therefore the lack of studies in this field and a sizeable inter-observer variability do not justify the widespread reliance on the traditional diameter-based methods for endograft sizing.

Compliance of postendovascular aortic aneurysm repair imaging surveillance

Imaging surveillance after endovascular aortic aneurysm repair (EVAR) is critical. In this study we analyzed compliance with imaging surveillance after EVAR and its effect on clinical outcomes. Retrospective analysis of prospectively collected data of 565 EVAR patients (August 2001-November 2013), who were followed using duplex ultrasound and/or computed tomography angiography. Patients were considered noncompliant (NC) if they did not have any follow-up imaging for 2 years and/or missed their first post-EVAR imaging over 6 months. A Kaplan-Meier analysis was used to compare compliance rates in EVAR patients with hostile neck (HN) vs favorable neck (FN) anatomy (according to instructions for use). A multivariate analysis was also done to correlate compliance and comorbidities. Forty-three percent were compliant (7% had no follow-up imaging) and 57% were NC. The mean follow-up for compliant patients was 25.4 months (0-119 months) vs 31.4 months for NC (0-140 months). The mean number of imaging was 3.5 for compliant vs 2.6 for NC (P < .0001). Sixty-four percent were NC for HN patients vs 50% for FN patients (P = .0007). The rates of compliance at 1, 2, 3, 4, and 5 years for all patients were 78%, 63%, 55%, 45%, and 32%; and 84%, 68%, 61%, 54%, and 40% for FN patients; and 73%, 57%, 48%, 37%, and 25% for HN patients (P = .009). The NC rate for patients with late endoleak and/or sac expansion was 58% vs 54% for patients with no endoleak (P = .51). The NC rate for patients with late reintervention was 70% vs 53% for patients with no reintervention (P = .1254). Univariate and multivariate analyses showed that patients with peripheral arterial disease had an odds ratio of 1.9 (P = .0331), patients with carotid disease had an odds ratio of 2 (P = .0305), and HN patients had an odds ratio of 1.8 (P = .0007) for NC. Age and residential locations were not factors in compliance. Overall, compliance of imaging surveillance after EVAR was low, particularly in HN EVAR patients, and additional studies are needed to determine if strict post-EVAR surveillance is necessary, and its effect on long-term clinical outcome.

Adherence to endovascular aortic aneurysm repair device instructions for use guidelines has no impact on outcomes

Prior reports have suggested unfavorable outcomes after endovascular aortic aneurysm repair (EVAR) performed outside of the recommended instructions for use (IFU) guidelines. We report our long-term EVAR experience in a large multicenter registry with regard to adherence to IFU guidelines. Between 2000 and 2010, 489 of 1736 patients who underwent EVAR had preoperative anatomic measurements obtained from the M2S, Inc, imaging database (West Lebanon, NH). We examined outcomes in these patients with regard to whether they had met the device-specific IFU criteria. Primary outcomes were all-cause mortality and aneurysm-related mortality. Secondary outcomes were endoleak status, adverse events, reintervention, and aneurysm sac size change. The median follow-up for the 489 patients was 3.1 years (interquartile range, 1.6-5.0 years); 58.1% (n = 284) had EVAR performed within IFU guidelines (IFU-adherent group), and 41.9% (n = 205) had EVAR performed outside of IFU guidelines (IFU-nonadherent group). Preoperative anatomic data showed that 62.4% of the IFU-nonadherent group had short neck length, 10.2% had greater angulation than recommended, 7.3% did not meet neck diameter criteria, and 20% had multiple anatomic issues. A small portion (n = 49; 10%) of the 489 patients were lost to follow-up because of leaving membership enrollment (n = 28), moving outside the region (n = 10), or discontinuing image surveillance (n = 11). There was no significant difference in any of the primary or secondary outcomes between the IFU-adherent and IFU-nonadherent groups. Aneurysm sac size change at any time point during follow-up also did not differ significantly between the two groups. A Cox proportional hazard model showed that IFU nonadherence was not predictive of all-cause mortality (hazard ratio, 1.0; P = .91). Similarly, IFU nonadherence was not identified as a risk factor for aneurysm-related mortality or adverse events in stepwise Cox proportional hazards models. In our cohort of EVAR patients with detailed preoperative anatomic information and long-term follow-up, overall mortality and aneurysm-related mortality were unaffected by IFU adherence. In addition, rates of endoleak and reintervention after initial EVAR were similar, suggesting that lack of IFU-based anatomic suitability was not a driver of outcomes.

Duplex Ultrasonography and its Use in Surveillance Post-EVAR

After endovascular aortic aneurysm repair (EVAR), patients require annual surveillance with either CT scan or duplex ultrasonography (DU). These studies should be used to identify patients who require reintervention for EVAR complications. DU, a less expensive and radiation free option, has been shown to accurately predict aneurysm sac size and endoleak. In addition, using criteria of PSV<300 cm/s and PSV ratio <3.5, DU can rule out limb stenosis. After a normal post-procedure DU, only 2.2% of patients require reintervention within the first 3 years suggesting that less frequent follow-up may be utilized. DU is an important tool in the surveillance of EVAR patients.

Remodeling of aortic aneurysm and aortic neck on follow-up after endovascular repair with suprarenal fixation

The objective of this study was to evaluate the remodeling of abdominal aortic aneurysms after endovascular aortic aneurysm repair (EVAR) with the Zenith (Cook Medical, Bloomington, Ind) device. This was a retrospective study of anatomic data related to characteristics of the aortic neck diameter, iliac artery diameter, and aneurysm sac diameter collected during a clinical study of the Zenith device. In this study, 739 patients were observed for 2 years and 158 of them were observed for 5 years. The monthly rate of change for the neck diameter was more rapid in the early postoperative period (postoperative-30 days), with an expansion of 0.7 ± 0.09 mm/month, and during the third year of follow-up (24-36 months), with a monthly expansion rate of 0.10 ± 0.24 mm. The iliac arteries were also more prone to expansion during the first postoperative month (right iliac, 0.95 ± 0.08 mm/month; left iliac, 0.91 ± 0.08 mm/month) and in the next 6 months with a monthly expansion rate of 0.18 ± 0.02 mm and 0.21 ± 0.02 mm for the right and left iliac arteries, respectively. Remodeling of the aneurysm sac occurred mainly in the first postoperative year with a regression rate of 0.89 ± 0.05 mm/month between 1 and 6 months and 0.44 ± 0.04 mm/month for the second half of the year. The aneurysm sac regression rate dropped to 0.2 mm/month in the second postoperative year. Changes in the aortic neck diameter were statistically significant (P < .001) only at the 24- to 36-month postoperative interval. Changes in the aortic sac diameter were statistically significant (P < .001) at the 30-day to 6-month, 6- to 12-month, and 12- to 24-month intervals. Among patients who underwent reintervention, aortic sac expansion occurred primarily in the 24- to 36-month interval. Expansion of the aortic neck after EVAR for the Zenith endograft occurs mainly between 24 and 36 months; aortic aneurysm sac regression occurs more obviously at 1 to 12 months. Iliac arteries at the landing zone expand more rapidly in the first postoperative year. Late surveillance of EVAR patients is essential to avoid late complications after aortic remodeling.

Early and delayed rupture after endovascular abdominal aortic aneurysm repair in a 10-year multicenter registry

Rupture after abdominal endovascular aortic aneurysm repair (EVAR) is a function of graft maintenance of the seal and fixation. We describe our 10-year experience with rupture after EVAR. From 2000 to 2010, 1736 patients with abdominal aortic aneurysm (AAA) from 17 medical centers underwent EVAR in a large, regional integrated health care system. Preoperative demographic and clinical data of interest were collected and stored in our registry. We retrospectively identified patients with postoperative rupture, characterized as "early" and "delayed" rupture (≤30days and >30days after the initial EVAR, respectively), and identified predictors associated with delayed rupture. The overall follow-up rate was 92%, and the median follow-up was 2.7years (interquartile range, 1.2-4.4years) in these 1736 EVAR patients. We identified 20 patients with ruptures; 70% were male, the mean age was 79years, and mean AAA size at the initial EVAR was 6.3cm. Six patients underwent initial EVAR for rupture (n= 2) or symptomatic presentation (n= 4). Of the 20 post-EVAR ruptures, 25% (five of 20) were early, all occurring within 2days after the initial EVAR. Of these five patients, four had intraoperative adverse events leading directly to rupture, with one type I and one type III endoleak. Of the five early ruptures, four patients underwent endovascular repair and one received repair with open surgery, resulting in two perioperative deaths. Among the remaining 15 patients, the median time from initial EVAR to rupture was 31.1months (interquartile range, 13.8-57.3months). Most of these delayed ruptures (10 of 15) were preceded by AAA sac increases, including three patients with known endoleaks who underwent reintervention. Atthe time of delayed rupture, nine of 15 patients had new endoleaks. Among all 20 patients, six patients did not undergo repair (all delayed patients) and died, nine underwent repeated EVAR, and five had open repair. For patients who underwent repair for delayed rupture, mortality at 30days and 1year were 44.4% and 66.7%, respectively. Multivariable Cox regression analysis identified age 80 to 89 (hazard ratio, 3.3; 95% confidence interval, 1.1-9.4; P= .03), and symptomatic or ruptured initial indication for EVAR (hazard ratio, 7.4; 95% confidence interval, 2.2-24.8; P< .01) as significant predictors of delayed rupture. Rupture after EVAR is a rare but devastating event, and mortality after repair exceeds 60% at 1year. Most delayed cases showed late AAA expansion, thereby implicating late loss of seal and increased endoleaks as the cause of rupture in these patients and mandating vigilant surveillance.

Pelvic ischemia and quality of life scores after interventional occlusion of the hypogastric artery in patients undergoing endovascular aortic aneurysm repair

The aim of this study was to analyze the pelvic ischemic complications and their impact on quality of life after interventional occlusion of the hypogastric artery (IOHA) in patients undergoing endovascular aortic aneurysm repair (EVAR). Between January 2004 and April 2012, 638 consecutive patients with aortoiliac aneurysm treated by EVAR were prospectively registered in two teaching hospitals. We identified all EVAR patients who underwent IOHA. Demographic, clinical, and radiologic data were extracted from electronic databases and patient records as requested. All patients who survived the postoperative period took part in a quality of life survey, the Walking Impairment Questionnaire (WIQ), which included four items: pain, distance, walking speed, and stair climbing. Outcome measures included the 30-day rate of pelvic ischemic complications, the buttock claudication (BC) rate at 30 days and during follow-up, and the comparative WIQ scores between patients with persistent BC, those with regressive BC, and those who never had BC after the IOHA procedure. A total of 71 patients (97% men; mean age, 76 years ± 7.69) required 75 IOHA procedures. These were deemed proximal in 44 cases and distal in 31, with use of coil embolization in 64%, Amplatzer plug in 24%, or a combination of coils and plugs in 12%. The technical success rate was 100%. Two patients (2.8%) experienced fatal acute pelvic ischemic complications in the postoperative period after EVAR. Another patient died of iliac rupture during EVAR, leading to an operative mortality rate of 4.3%. Eighteen patients (25.3%) suffered BC, among whom 11 cases resolved at a median follow-up of 42 months. Young age (odds ratio, 0.92; 95% confidence interval, 0.85-0.99; P = .03) and distal IOHA (odds ratio, 3.5; 95% confidence interval, 1.01-11.51; P = .04) were independent predictors of BC occurrence. The actuarial rate of persistent BC was 85% at 18 months. The WIQ scores were lower for patients with persistent BC (median score, 35.04; interquartile range, 16.36; P = .001) compared with patients with regressive BC (median score, 76.5; interquartile range, 36.66; P = .02) or those who never experienced BC after the IOHA procedure (median score, 65.34; interquartile range, 10.94; P < .0003). Pelvic ischemia associated with IOHA may be severe and lead to fatality after EVAR. Our data show that BC may lead to severe quality of life impairment when it does not regress during follow-up.

Late open conversion after failed endovascular aortic aneurysm repair

Endovascular aortic aneurysm repair (EVAR) is widely used for the treatment of abdominal aortic aneurysms. Complications secondary to EVAR are also treated with endovascular techniques. When this is not applicable, open surgical repair is mandatory. This study aims to present our experience in open surgical repair after failed EVAR. Within the period from 2004 through 2013, 18 patients (17 men; mean age, 73.9 years) were operated on because of EVAR failure due to persistent type II endoleak (n = 10), type I or III endoleak (n = 3), mixed-type endoleaks (n = 2), stent graft thrombosis (n = 2), and aortoenteric fistulae (n = 1). Stent grafts used for EVAR were Zenith (n = 8), Talent (n = 4), Excluder (n = 4), and Anaconda (n = 2). Mean time interval between EVAR and open conversion was 36 months (range, 2-120 months). Fifteen (83.3%) operations were elective, and three (16.7%) were urgent due to aneurysm rupture (n = 2) and aortoenteric fistula (n = 1). Six (33.3%) patients with type II endoleak were treated with simple ligation of the culprit vessels, without aortic clamping and stent graft explantation. In six (33.3%) patients, the stent graft was partially removed except from the segment attached to the proximal neck, while in five (27.8%) patients, complete removal of the stent graft was necessary. Finally, in one patient, with type III endoleak, a hybrid endovascular and open repair was performed. Clamping of the aorta was necessary in 12 (66.7%) patients (infrarenal, n = 10 or suprarenal, n = 2). Overall operative mortality was 5.6%. Postoperative complications included one abdominal wall defect requiring surgical revision and paroxysmal atrial fibrillation both in the same patient, and one case of pulmonary infection, requiring prolonged intubation and intensive care unit stay for 6 days. Late open conversion after failed EVAR remains challenging. Avoidance of aortic cross-clamping and if possible, partial or total preservation of the stent graft may improve outcomes in terms of operative mortality and morbidity. Elective operations seem to be associated with better outcomes, prompting thus for close follow-up of EVAR patients and early decision for conversion if other options are doubtful.

Predictors of percutaneous access failure requiring open femoral surgical conversion during endovascular aortic aneurysm repair

To determine predictors of percutaneous (PEVAR) access failure requiring conversion to an open approach (OEVAR) during endovascular aortic aneurysm repair (EVAR). A single-center retrospective review of all EVAR patients from January 2009 through June 2011 with multivariate analysis of clinical and anatomic variables that could impact access outcome was conducted. Target vessel calcification was categorized as mild, moderate, or severe based on circumferential calcium arc (<⅓, ⅓ to ½, and >½ respectively), dyslipidemia (defined as low-density lipoprotein >130 mg/dL or receiving lipid lowering medication), and obesity (defined as body mass index [BMI] >30). We investigated 400 access sites for 200 patients who underwent EVAR. The study cohort's characteristics included an average age of 72.8 ± 9.0 years, vessel size of 9.6 ± 1.8 mm, sheath size of 17.1 ± 3.0 Fr, BMI of 27.6 ± 5.3, and estimated glomular filtration rate of 68.5 ± 24.2 mL/min. Comorbidities included dyslipidemia in 129 patients (64.5%) and diabetes in 54 patients (27%). There were 132 OEVAR (66 patients), two mixed OEVAR with contralateral PEVAR (one patient), and 266 (133 patients) PEVAR approaches. Use of PEVAR increased over time (45.5% [2009], 77.8% [2010], and up to 88.5% [2011]; P = .001) while conversions decreased (24.3% [2009], 8.7% [2010], and 4.3% [2011]; P = .001]. More OEVAR patients (35.8%) stayed longer than 3 days compared with 21.1% for PEVAR (P = .028). For the 266 PEVAR approaches, 32 access sites (12.0%) had to be converted. Severely calcified arteries were most predictive of conversion (odds ratio [OR], 36.4; P < .001). Year of procedure (2010; OR, 0.17; P = .001; 2011, OR, 0.20; P = .049), female gender (OR, 3.1; P = .017), moderately calcified arteries (OR, 2.5; P = .085), and age (OR, 2.3 [per decade]; P = .002) were all also significant. Vessel size, sheath size, and BMI were found to be nonsignificant predictors of conversion. PEVAR was found to be safe, reliable, and feasible. Several factors, including learning curve, vessel calcification, age, and female gender predicted conversion of PEVAR to OEVAR.

Duplex ultrasound imaging alone is sufficient for midterm endovascular aneurysm repair surveillance: A cost analysis study and prospective comparison with computed tomography scan

Early in our experience with endovascular aortic aneurysm repair (EVAR) we performed both serial computed tomography scans and duplex ultrasound (DU) imaging in our post-EVAR surveillance regimen. Later we conducted a prospective study with DU imaging as the sole surveillance study and determined cost savings and outcome using this strategy. From September 21, 1998, to May 30, 2008, 250 patients underwent EVAR at our hospital. Before July 1, 2004, EVAR patients underwent CT and DU imaging performed every 6 months during the first year and then annually if no problems were identified (group 1). We compared aneurysm sac size, presence of endoleak, and graft patency between the two scanning modalities. After July 1, 2004, patients underwent surveillance using DU imaging as the sole surveillance study unless a problem was detected (group 2). CT and DU imaging charges for each regimen were compared using our 2008 health system pricing and Medicare reimbursements. All DU examinations were performed in our accredited noninvasive vascular laboratory by experienced technologists. Statistical analysis was performed using Pearson correlation coefficient. DU and CT scans were equivalent in determining aneurysm sac diameter after EVAR (P < .001). DU and CT were each as likely to falsely suggest an endoleak when none existed and were as likely to miss an endoleak. Using DU imaging alone would have reduced cost of EVAR surveillance by 29% ($534,356) in group 1. Cost savings of $1595 per patient per year were realized in group 2 by eliminating CT scan surveillance. None of the group 2 patients sustained an adverse event such as rupture, graft migration, or limb occlusion as a result of having DU imaging performed as the sole follow-up modality. Surveillance of EVAR patients can be performed accurately, safely, and cost-effectively with DU as the sole imaging study.