Risk Factors, Dynamics, and Clinical Consequences of Aortic Neck Dilatation after Standard Endovascular Aneurysm Repair

The Effect of EndoAnchors on Aneurysm Sac Regression for Patients Treated With Infrarenal Endovascular Repair With Hostile Neck Anatomies: A Propensity Scored Analysis

PURPOSE

To analyze sac evolution patterns in matched patients with hostile neck anatomy (HNA) treated with standard endovascular aneurysm repair (sEVAR) and endosutured aneurysm repair (ESAR).

METHODS

Observational retrospective study using prospectively collected data between June 2010 and December 2019. ESAR group data were extracted from the primary arm of the PERU registry with an assigned identifier (NCT04100499) at 8 centers and those from the sEVAR came from 4 centers. Suitability for inclusion required: no proximal endograft adjuncts (besides EndoAnchor use), ≤15 mm neck length and minimum of 12-months follow-up imaging. Bubble-shaped neck (noncylindrical short neck with discontinuous seal) aspect was analyzed. Both groups were analyzed using propensity score matching (PSM) for aortic neck length, width, angulation, and device fixation type. Main outcome assessed was sac evolution patterns (sac expansion and regression were defined as >5mm increase or decrease, of the maximum sac diameter respectively; all AAAs within this ±5 mm range in diameter change were considered stable) and secondary outcomes were type-Ia endoleaks; other endoleaks and mortality. A power analysis calculation >80% was confirmed for sac regression evaluation.

RESULTS

After exclusions, PSM resulted in 96 ESAR and 96 sEVAR patients. Mean imaging follow-up (months) was 44.4±21.3 versus 43.0±19.6 (p=0.643), respectively. The overall number of patients achieving sac regression was higher in the ESAR group (n=57, 59.4% vs n=31, 32.3%; p<0.001) and the cumulative sac regression achieved at 5 years was 65% versus 38% (p=0.003) in favor of the ESAR group. There were no statistically significant differences in type-Ia endoleak and/or other endoleaks. Univariate analysis for sac regression patients in the sEVAR and ESAR group individually showed the bubble-shape neck as a predictor of sac regression failure. There were no statistical differences in overall and aneurysm-related mortality.

CONCLUSION

Endosutured aneurysm repair provided improved rates of sac regression for patients with AAA and HNA when compared with sEVAR at midterm and up to 5 years, despite similar rates of type-Ia endoleaks, and the need to consider some important limitations. The presence of bubble-shaped neck was a predictor of sac regression failure for both groups equally.

CLINICAL IMPACT

The use of EndoAnchors aids and improves EVAR treatment in hostile neck anatomies by an increased rate of sac regression when compared to EVAR treatment alone in up to 5 year analysis. Moreover, a trend to reduced number of type Ia endoleaks is also achieved, although not significant in the present study. This data, adds to current and growing evidence on the usefulness of EndoAnchors for AAA endovascular treatment.

Midterm Outcomes and Aneurysm Sac Dynamics Following Fenestrated Endovascular Aneurysm Repair after Previous Endovascular Aneurysm Repair

OBJECTIVE

Fenestrated endovascular aneurysm repair (FEVAR) is a feasible option for aortic repair after endovascular aneurysm repair (EVAR), due to improved peri-operative outcomes compared with open conversion. However, little is known regarding the durability of FEVAR as a treatment for failed EVAR. Since aneurysm sac evolution is an important marker for success after aneurysm repair, the aim of the study was to examine midterm outcomes and aneurysm sac dynamics of FEVAR after prior EVAR.

METHODS

Patients undergoing FEVAR for complex abdominal aortic aneurysms from 2008 to 2021 at two hospitals in The Netherlands were included. Patients were categorised into primary FEVAR and FEVAR after EVAR. Outcomes included five year mortality rate, one year aneurysm sac dynamics (regression, stable, expansion), sac dynamics over time, and five year aortic related procedures. Analyses were done using Kaplan-Meier methods, multivariable Cox regression analysis, chi square tests, and linear mixed effect models.

RESULTS

One hundred and ninety-six patients with FEVAR were identified, of whom 27% (n = 53) had had a prior EVAR. Patients with prior EVAR were significantly older (78 ± 6.7 years vs. 73 ± 5.9 years, p < .001). There were no significant differences in mortality rate. FEVAR after EVAR was associated with a higher risk of aortic related procedures within five years (hazard ratio [HR] 2.6; 95% confidence interval [CI] 1.1 - 6.5, p = .037). Sac dynamics were assessed in 154 patients with available imaging. Patients with a prior EVAR showed lower rates of sac regression and higher rates of sac expansion at one year compared with primary FEVAR (sac expansion 48%, n = 21/44, vs. 8%, n = 9/110, p < .001). Sac dynamics over time showed similar results, sac growth for FEVAR after EVAR, and sac shrinkage for primary FEVAR (p < .001).

CONCLUSION

There were high rates of sac expansion and a need for more secondary procedures in FEVAR after EVAR than primary FEVAR patients, although this did not affect midterm survival. Future studies will have to assess whether FEVAR after EVAR is a valid intervention, and the underlying process that drives aneurysm sac growth following successful FEVAR after EVAR.

Midterm outcomes of "wide neck" abdominal aortic aneurysm after open or endovascular repair in two European centers: a propensity score matching analysis

BACKGROUND

The aim of this study was to compare mid-term clinical and morphological outcomes in patients undergoing open (OR) and endovascular aortic repair (EVAR) with a proximal wide neck abdominal aortic aneurysm (WN-AAA).

METHODS

Between 2009 and 2014 data of all patients undergoing OR at IRCCS San Raffaele Hospital and EVAR at German Aortic Center Hamburg were retrospectively analyzed. Primary endpoints were aneurysm-related mortality at 5 years, reintervention, and overall mortality. Secondary endpoint was proximal neck enlargement. A 1:1 propensity score matching (PSM) was performed. Survival and freedom from AAA-related reintervention were investigated in matched OR and EVAR group by Kaplan-Meier analysis.

RESULTS

Of all OR performed at IRCCS San Raffaele Hospital 70 were found to have a proximal neck >28 mm (mean age: 69.8±7.2 years, 67 [95.71%] male); of all consecutive EVAR performed at German Aortic Center Hamburg, 52 required an endograft size of at least 32 mm (mean age of 73.1±8.7 years, 49 [94.2%] male). After PSM, the study cohort consisted of 30 OR and EVAR. One early mortality was registered in both groups (P=NS). Mid-term freedom from reintervention compared in OR and EVAR, with no statistically significant differences (P=0.979). Eight (15.4%) patients treated with EVAR developed a significant proximal diameter enlargement (≥3 mm) while only 1 (1.4%) patient in the OR group had the same evolution (P<0.01).

CONCLUSIONS

In WN-AAA neck enlargement is observed more frequently in patients undergoing EVAR, but reintervention rate was similar in the 2 groups, demonstrating that both options were safe and effective.

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

PURPOSE

Imaging surveillance following endovascular aneurysm repair (EVAR) is strictly recommended. This study investigates the value of endograft apposition and position relative to the aortic neck on the first postoperative computed tomography angiography (CTA) in determining patients at risk for a late type Ia endoleak (T1aEL).

MATERIALS AND METHODS

Patients with a T1aEL after the first postoperative CTA were selected from a consecutive database and matched with uncomplicated controls. Endograft apposition and position, including the shortest apposition length (SAL), were determined on the first postoperative CTA. The SAL is the shortest distance between the proximal endograft fabric and the first slice where circumferential apposition with the aortic wall is lost. Differences in endograft apposition at the first postoperative CTA were compared between groups. Logistic regression analysis identified independent predictors for late T1aEL.

RESULTS

A total of 32 patients with a late T1aEL were included and matched with 32 uncomplicated controls. Median follow-up after primary EVAR was 62.0 (interquartile range [IQR]: 36.8, 83.5) months in the T1aEL group compared with 47.5 (IQR: 34.0, 79.3) months in the control group; p=0.265. Median preoperative neck diameter was significantly larger in the T1aEL group than in the control group (26.6 [IQR: 24.9, 29.6] mm versus 23.4 [IQR: 22.5, 25.3] mm); p<0.001. Patients in the T1aEL group had a median SAL of 11.6 (IQR: 4.3, 20.5) mm compared with 20.7 (IQR: 13.1, 24.9) mm in the control group; p=0.002. SAL <10mm on the first postoperative CTA (odds ratio [OR]: 9.63, 95% confidence interval [CI]: 1.60-57.99) and larger neck diameter (OR: 1.80, 95% CI: 1.26-2.57) were independent predictors for developing a late T1aEL.

CONCLUSION

Preoperative neck diameter and SAL on the first postoperative CTA following EVAR are important predictors for the development of a late T1aEL. Patients with a SAL of <10mm had a significantly higher risk of developing a late T1aEL. Future research should determine whether these patients would benefit from reintervention before an actual T1aEL is present.

CLINICAL IMPACT

Understanding the mechanisms of endovascular aneurysm repair failure is essential to further enhance clinical outcomes. Adequate proximal sealing is necessary to foster freedom from type 1a endoleak. This study demonstrates that the shortest apposition length (SAL) at the first postoperative computed tomography angiography (CTA) is able to identify patients at risk for a late type 1a endoleak. Especially patients with a SAL <10mm are at high risk. Currently, the guidelines advice repeated imaging with CTA in patients with a seal <10mm. Future research should determine whether these patients would benefit from re-intervention before an actual type 1a endoleak is present.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Implications of aortic neck dilation following thoracic endovascular aortic repair

OBJECTIVE

This article reports on a retrospective observational study designed to evaluate the incidence, etiology, and clinical implications of aortic neck dilation following thoracic endovascular aortic repair (TEVAR) for aneurysms with landing zones II and III.

METHODS

The study included 37 patients who underwent TEVAR and had postoperative computed tomography angiography available within 30 days and at least one computed tomography angiography at 1 year postoperatively. The primary end point was proximal aortic dilation (defined as growth ≥5 mm or ≥10% of the original diameter), and secondary end points included annual growth of the aneurysmal sac, device migration, endoleak, and reintervention with additional neck-related adverse events. The measurements taken during follow-up included the maximum diameter of the aneurysm and aortic diameter at various locations relative to the stent graft.

RESULTS

During follow-up, a significant increase in aortic diameter was observed at the proximal edge of TEVAR. The estimated freedom from 5 mm or 10% proximal aortic neck growth at 1, 2, and 3 years was 81%, 70%, and 65%, respectively. At the proximal edge of TEVAR the type III aortic arch was significantly associated with 5 mm growth during follow-up (P = .047) and this growth (5 mm or 10%) as well as a 10% increase at +20 mm were significantly associated with more aortic-related reinterventions. Moreover, an aortic diameter at the start <36 mm was associated with a greater increase during follow-up (area under curve in receiver operating characteristic >80%; P < .05).

CONCLUSIONS

The study concludes that proximal aortic dilation after TEVAR is a common and progressive phenomenon, and the management strategies for aortic neck dilation, including surveillance, secondary interventions, and open conversion, should be considered carefully to optimize patient outcomes and improve the long-term success of the procedure.

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

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

A Scoping Review on the Incidence, Risk Factors, and Outcomes of Proximal Neck Dilatation after Standard and Complex Endovascular Repair for Abdominal Aortic Aneurysms

Background: To define proximal neck dilation (PND) after standard endovascular aneurysm repair (EVAR) and fenestrated EVAR (FEVAR), determining: incidence and risk factors; evidence base that links PND to outcomes of patients; recurring themes or gaps in the literature. Methods: We performed a scoping review and included only full-text English articles with follow-up focusing on PND in patients undergoing EVAR or FEVAR, published between 2000 and 2022. The following PICO question was used to build the search equation: in patients with abdominal-aortic-aneurysm (AAA) (Population) undergoing endovascular repair (Intervention), what are the incidence, risk factors and prognosis of radiologically defined PND (Comparison) on short-term and long-term outcomes (Outcomes)? Results: 15 articles were included after review. Measurement protocols for proximal aortic neck (PAN) varied among individual studies and the definition of PND resulted as heterogeneous. Rate of patients with a PND ranged between 0% and 41%. Large proximal neck (>28 mm) and excessive graft sizing (30%) were predictors for PND. New endografts with low outward radial forces and FEVAR seemed to be protective. Surgical conversion was the definitive option in the case of patients unfit for other endovascular treatments. Conclusions: PND is a frequent finding after EVAR and FEVAR. Excessive graft oversizing and large baseline PAN were predictors of neck enlargement, independently by the type of standard endograft used. FEVAR may be considered protective against complications, together with endografts using low outward radial forces. Lifelong radiological follow-up is mandatory.

A systematic review and meta-analysis of proximal aortic neck dilatation after endovascular abdominal aortic aneurysm repair

OBJECTIVE

To provide an updated systematic literature review summarizing current evidence on aortic neck dilatation (AND) after endovascular aortic aneurysm repair (EVAR) in patients with infrarenal abdominal aortic aneurysm.

METHODS

An extensive electronic search in major electronic databases was conducted between January 2000 and December 2021. Eligible for inclusion were observational studies that followed up with patients (n ≥ 20) undergoing EVAR with self-expanding endografts, for 12 or more months, evaluated AND with computed tomography angiography and provided data on relevant outcomes. The primary end point was the incidence of AND after EVAR, and the secondary end points were the occurrence of type Ia endoleak, stent graft migration, secondary rupture, and reintervention.

RESULTS

We included 34 studies with a total sample of 12,038 patients (10,413 men; median age, 71 years). AND was defined clearly in 18 studies, but significant differences in AND definition were evidenced. The pooled incidence of AND based on quantitative analysis of 16 studies with a total of 9201 patients (7961 men; median age, 72 years) was calculated at 22.9% (95% confidence interval [CI], 14.4-34.4) over a follow-up period ranging from 12 months to 14 years. The risk of a type Ia endoleak was significantly higher in AND patients compared with those without AND (odds ratio, 2.95; 95% CI, 1.10-7.93; P = .030). Similarly, endograft migration was more common in the AND group compared with the non-AND group (odds ratio, 5.95; 95% CI, 1.80-19.69; P = .004). The combined incidence of secondary rupture and reintervention did not differ significantly between the two groups, even though the combined effect was in favor of the non-AND group.

CONCLUSIONS

Proximal AND after EVAR is common and occurs in a large proportion of patients with infrarenal abdominal aortic aneurysm. AND can influence the long-term durability of proximal endograft fixation and is significantly related to adverse outcomes, often leading to reinterventions.

Abdominal aortic aneurysm neck dilatation and sac remodeling in fenestrated compared to standard endovascular aortic repair

OBJECTIVE

Contemporary commercially available endovascular devices for the treatment of abdominal aortic aneurysm (AAA) include standard endovascular aortic repair (sEVAR) or fenestrated EVAR (fEVAR) endografts. However, aortic neck dilatation (AND) can occur in nearly 25% of patients following EVAR, resulting in loss of proximal seal with risk of aortic rupture. AND has not been well characterized in fEVAR, and direct comparisons studying AND between fEVAR and sEVAR have not been performed. This study aims to analyze AND in the infrarenal and suprarenal aortic segments, including seal zone, and quantify sac regression following fEVAR implantation compared to sEVAR.

METHOD

A retrospective review of prospectively collected data on 20 consecutive fEVAR patients (Cook Zenith® Fenestrated) and 20 sEVAR (Cook Zenith®) patients was performed. Demographic data, anatomic characteristics, procedural details, and clinical outcome were analyzed. Pre-operative, post-operative (1 month), and longest follow-up CT scan at an average of 29.3 months for fEVAR and 29.8 months for sEVAR were analyzed using a dedicated 3D workstation (iNtuition, TeraRecon Inc, Foster City, California). Abdominal aortic aneurysm neck diameter was measured in 5 mm increments, ranging from 20 mm above to 20 mm below the lowest renal artery. Sub-analysis comparing the fEVAR to the sEVAR group at 12 months and at greater than 30 months was performed. Standard statistical analysis was done.

RESULTS

Demographic characteristics did not differ significantly between the two cohorts. The fEVAR group had a larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length. On follow-up imaging, the suprarenal aortic segment dilated significantly more at all locations in the fEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared to the sEVAR group. Compared to the sEVAR cohort, the fEVAR patients demonstrated significantly greater positive sac remodeling as evident by more sac diameter regression, and elongation of distance measured from the celiac axis to the most cephalad margin of the sac. Device migration, endoleak occurrence, re-intervention rate, and mortalities were similar in both groups.

CONCLUSION

Compared to sEVAR, patients undergoing fEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in fEVAR patients, appears more stable in the post-operative period as compared to sEVAR. Moreover, the fEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in fEVAR may result in a previously undescribed increased level of protection against infrarenal neck dilatation. We hypothesize that the resultant decreased endotension conferred by better seal zone may be responsible for a more dramatic sac shrinkage in fEVAR.

Clinical presentation, operative management, and long-term outcomes of rupture after previous abdominal aortic aneurysm repair

OBJECTIVE

The aim of the present study was to evaluate the presentation trends, intervention, and survival of patients who had been treated for late abdominal aortic aneurysm rupture (LAR) after open repair (OR) or endovascular aortic aneurysm repair (EVAR).

METHODS

We reviewed the clinical data from a single-center, retrospective database for patients treated for LAR from 2000 to 2020. The end points were the 30-day mortality, major postoperative complication, and survival. The outcomes between LAR managed with EVAR (group I) vs OR were compared (group II).

RESULTS

Of 390 patients with infrarenal aortic rupture, 40 (10%) had experienced aortic rupture after prior aortic repair and comprised the LAR cohort (34 men; age 78 ± 8 years). LAR had occurred before EVAR in 30 and before OR in 10 patients. LAR was more common in the second half of the study with 32 patients after 2010. LAR after prior OR was secondary to ruptured para-anastomotic pseudoaneurysms. After initial EVAR, LAR had occurred despite reintervention in 17 patients (42%). The time to LAR was shorter after prior EVAR than after OR (6 ± 4 vs 12 ± 4 years, respectively; P = .003). Treatment for LAR was EVAR for 25 patients (63%; group I) and OR for 15 (37%, group II). LAR after initial OR was managed with endovascular salvage for 8 of 10 patients. Endovascular management was more frequent in the latter half of the study period. In group I, fenestrated repair had been used for seven patients (28%). Salvage for the remaining cases was feasible with EVAR, aortic cuffs, or limb extensions. The incidence of free rupture, time to treatment, 30-day mortality (8% vs 13%; P = .3), complications (32% vs 60%; P = .1), and disposition were similar between the two groups. Those in group I had had less blood loss (660 vs 3000 mL; P < .001) and less need for dialysis (0% vs 33%; P < .001) than those in group II. The median follow-up was 21 months (interquartile range, 6-45 months). The overall 1-, 3-, and 5-year survival was 76%, 52%, and 41%, respectively, and was similar between groups (28 vs 22 months; P = .48). Late mortality was not related to the aorta.

CONCLUSIONS

LAR after abdominal aortic aneurysm repair has been encountered more frequently in clinical practice, likely driven by the frequency of EVAR. However, most LARs, including those after previous OR, can now be salvaged with endovascular techniques with lower morbidity and mortality.

Midterm outcomes of AFX2 endografts used in combination with aortic cuffs

OBJECTIVE

Type III endoleaks after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with the Endologix unibody endograft remain a major concern, despite fabric, system, and instructional updates. The purpose of this study was to examine real-world outcomes of repairing AAAs using the current version of the AFX2 main body in combination with an aortic cuff, specifically focusing on type III endoleaks and morphological changes of the endograft.

METHODS

We recruited facilities in Japan that used AFX2 combined with an aortic cuff for at least five cases between April 2017 and March 2018. A total of 175 cases in 24 facilities were analyzed. Patients' background information, including anatomic factors, operative findings, device component variations, and midterm outcomes at 3 years after the EVAR were collected. The data on computed tomography scans from cases registered as types I and III endoleaks and migration from each institute were sent to our department for verification.

RESULTS

The mean patient age was 74.6 ± 8.1 years, and 48 cases (27%) were saccular aneurysms. The mean fusiform and saccular AAA diameters were 50.5 ± 5.8 mm and 43.5 ± 8.9 mm, respectively. No in-hospital deaths occurred. Data at 3 years, including computed tomography images, of 128 cases were analyzed. Overall survival, freedom from aneurysm-related mortality, and freedom from reintervention rates at 3 years were 85.8%, 99.3%, and 87.3%, respectively. There were three, one, and three cases of types I, IIIa, and IIIb endoleaks without sac dilatations, respectively. Among five migration cases, one case of aortic cuff migration presented as a type Ia endoleak, and four cases demonstrated sideways displacement, one of which presented as a type IIIa endoleak. The sac regression and enlargement rates at 3 years were 41.4% and 20.5% in the fusiform group and 44.2% and 16.7% in the saccular group, respectively. The proximal neck diameter slightly increased from 20.8 ± 2.7 mm before the EVAR to 22.2 ± 4.6 mm after the repair.

CONCLUSIONS

Midterm outcomes of the AFX2 used in combination with an aortic cuff were acceptable, considering the rates of types I and III endoleaks. However, there were cases of sideways displacement that could cause future type IIIa endoleaks. When the AFX2 is used in combination with an aortic cuff, close surveillance for endograft deformations and subsequent adverse events, including type III endoleaks, is needed.

A Statistical Shape Model of Infrarenal Aortic Necks in Patients With and Without Late Type Ia Endoleak After Endovascular Aneurysm Repair

PURPOSE

Hostile aortic neck characteristics, including short length, severe suprarenal and infrarenal angulation, conicity, and large diameter, have been associated with increased risk for type Ia endoleak (T1aEL) after endovascular aneurysm repair (EVAR). This study investigates the mid-term discriminative ability of a statistical shape model (SSM) of the infrarenal aortic neck morphology compared with or in combination with conventional measurements in patients who developed T1aEL post-EVAR.

MATERIALS AND METHODS

The dataset composed of EVAR patients who developed a T1aEL during follow-up and a control group without T1aEL. Principal component (PC) analysis was performed using a parametrization to create an SSM. Three logistic regression models were created. To discriminate between patients with and without T1aEL, sensitivity, specificity, and the area under the receiver operating characteristic (ROC) curve (AUC) were calculated.

RESULTS

In total, 126 patients (84% male) were included. Median follow-up time in T1aEl group and control group was 52 (31, 78.5) and 51 (40, 62.5) months, respectively. Median follow-up time was not statistically different between the groups (p=0.72). A statistically significant difference between the median PC scores of the T1aEL and control groups was found for the first, eighth, and ninth PC. Sensitivity, specificity, and AUC values for the SSM-based versus the conventional measurements-based logistic regression models were 79%, 70%, and 0.82 versus 74%, 73%, and 0.85, respectively. The model of the SSM and conventional measurements combined resulted in sensitivity, specificity, and AUC of 81%, 81%, and 0.92.

CONCLUSION

An SSM of the infrarenal aortic neck determines its 3-dimensional geometry. The SSM is a potential valuable tool for risk stratification and T1aEL prediction in EVAR. The SSM complements the conventional measurements of the individual preoperative infrarenal aortic neck geometry by increasing the predictive value for late type Ia endoleak after standard EVAR.

CLINICAL IMPACT

A statistical shape model (SSM) determines the 3-dimensional geometry of the infrarenal aortic neck. The SSM complements the conventional measurements of the individual pre-operative infrarenal aortic neck geometry by increasing the predictive value for late type Ia endoleaks post-EVAR. The SSM is a potential valuable tool for risk stratification and late T1aEL prediction in EVAR and it is a first step toward implementation of a treatment planning support tool in daily clinical practice.

The effect of supraceliac versus infraceliac landing zone on outcomes following fenestrated endovascular repair of juxta-/pararenal aortic aneurysms

OBJECTIVE

With increasing experience in fenestrated endovascular aneurysm repair (FEVAR) over time, devices designed to treat juxta-/pararenal aortic aneurysms have evolved in complexity to extend to more proximal landing zones and incorporate more target vessels. We assessed perioperative outcomes in patients who underwent juxta-/pararenal FEVAR with supraceliac vs infraceliac sealing in the Vascular Quality Initiative.

METHODS

We identified all patients who underwent elective FEVAR (commercially available FEVAR and physician-modified endografts) for juxta-/pararenal aortic aneurysms in the Vascular Quality Initiative between 2014 and 2021. Supraceliac sealing was defined as proximal sealing in aortic zone 5, or zone 6 with a celiac scallop/fenestration/branch or celiac occlusion. Primary outcomes were perioperative and 3-year mortality. Secondary outcomes included completion endoleaks, in-hospital complications, and factors associated with 3-year mortality. We calculated propensity scores and used inverse probability-weighted Cox regression and logistic regression modeling to assess outcomes.

RESULTS

Among 1486 patients identified, 1246 patients (84%) underwent infraceliac sealing, and 240 patients (16%) underwent supraceliac sealing. Of the supraceliac patients, 74 (31%) had a celiac scallop, 144 (60%) had a celiac fenestration/branch, and 22 (9.2%) had a celiac occlusion (intentional or unintentional). After risk-adjusted analyses, there were no differences in perioperative mortality following supraceliac sealing compared with infraceliac sealing (2.3% vs 2.5%; hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.26-1.8; P = .42), or 3-year mortality (12% vs 15%; HR, 0.89; 95% CI, 0.53-1.5; P = .67). Compared with infraceliac sealing, supraceliac sealing was associated with lower odds of type-IA completion endoleaks (odds ratio [OR], 0.24; 95% CI, 0.05-0.67), but higher odds of any complication (12% vs 6.9%; OR, 1.6; 95% CI, 1.01-2.5) including cardiac complications (5.5% vs 1.9%; OR, 2.6; 95% CI, 1.3-5.1), lower extremity ischemia (3.0% vs 0.9%; OR, 3.2; 95% CI, 1.02-9.5), and acute kidney injury (16% vs 11%; OR, 1.6; 95% CI, 1.05-2.3). Though non-significant, there was a trend towards higher risk of spinal cord ischemia following supraceliac sealing compared with infraceliac sealing (1.7% vs 0.8%; OR, 2.2; 95% CI, 0.70-6.4). There were no differences in bowel ischemia between groups (1.7% vs 1.5%; OR, 0.83; 95% CI, 0.24-1.23). A more proximal aneurysm disease extent was associated with higher 3-year mortality (HR zone 8 vs 9, 1.7; 95% CI, 1.1-2.5), whereas procedural characteristics had no influence.

CONCLUSIONS

Compared with sealing at an infraceliac level, supraceliac sealing was associated with lower risk of type IA endoleaks and similar mortality. However, clinicians should be aware that supraceliac sealing was associated with higher perioperative morbidity. Future studies with longer follow-up are needed to adequately assess durability differences to comprehensively weigh the risks and benefits of utilizing a higher sealing zone within the visceral aorta for juxta-/pararenal FEVAR.

Risk factors and adverse events related to supra- and infra-renal aortic dilation at twelve months after endovascular abdominal aortic aneurysm repair

BACKGROUND

Aortic remodeling and its effect on adverse events after endovascular abdominal aneurysm repair (EVAR) remain under investigation. This study aimed to assess aortic diameter alterations after EVAR, related risk factors and consequences to proximal sealing at 12 months.

METHODS

A single-center retrospective analysis of consecutive EVAR patients was undertaken. All patients underwent computed tomography angiography, preoperatively, at 1^st and 12^th month. The infrarenal diameter was measured just below the inferior renal artery, at 7 mm and 15 mm while the suprarenal, just above the superior renal artery (SRA), superior mesenteric artery (SMA) and just below the celiac trunk. Neck-related adverse events included migration and endoleak Ia.

RESULTS

A hundred fifty patients were included. At 1^st month, no significant diameter alteration was recorded at any level. At 12^th month, all infra-renal diameters increased (P<0.001) and diameters at SRA and SMA also augmented (P=0.024 and P=0.007, respectively). Neck diameter >29 mm, supra-renal fixation and oversizing >20% were associated to dilation at 12^th month. Neck adverse events were related to diameter alterations below the inferior renal artery (P=0.017), SRA (P=0.007) and SMA (P=0.05).

CONCLUSIONS

During the 12-month follow-up, aortic dilation may be detected from the supra-renal aorta to the total neck length. Neck dilation may be attributed to large neck diameter, supra-renal fixation, and aggressive oversizing. Neck-related adverse events are more common in patients with aortic dilation at 12 months.

Incidence, Prognostic Significance, and Risk Factors of Acute Kidney Injury Following Elective Infrarenal and Complex Endovascular Aneurysm Repair

OBJECTIVE

Acute kidney injury (AKI) is a well known complication following cardiovascular procedures. The objective was to assess the incidence, risk factors, and prognostic significance of AKI after infrarenal endovascular aneurysm repair (EVAR) and complex EVAR (cEVAR; fenestrated or branched EVAR).

METHODS

Consecutive patients undergoing elective infrarenal EVAR or cEVAR between 2000 and 2018 in two large teaching hospitals in the Netherlands were included. AKI was determined by serum creatinine levels increasing > 1.5 times or by an absolute increase of 26.5 mmol/L from baseline value (KDIGO criteria). The primary outcome was incidence of peri-operative AKI development. Secondary outcomes included mid-term renal function (RIFLE criteria), overall survival, and risk factors for AKI development. To determine survival and risk factors for AKI, multivariable Cox regression and logistic regression analyses were performed, accounting for pre-operative renal function and other confounders.

RESULTS

In total, 540 patients who underwent infrarenal EVAR with 147 patients who underwent cEVAR also included. The incidence of AKI was 8.7% (n = 47) in infrarenal EVAR patients and 23% (n = 34) in cEVAR patients (fenestrated EVAR 18%; branched EVAR 38%). In contrast to patients without AKI, the renal function of surviving patients with AKI remained significantly reduced at six weeks and did not return to pre-operative values following infrarenal EVAR (three year estimated glomerular filtration rate [eGFR] 59.3 ± 23.1 mL/min/1.73m2vs. pre-operative eGFR 74.0 ± 21.7 mL/min/1.73m2; p = .006) or following cEVAR (three year eGFR 52.0 ± 23.7 mL/min/1.73m2vs. pre-operative eGFR 65.4 ± 18.6 mL/min/1.73m2; p = .082). After risk adjusted analysis, compared with non-AKI, post-operative AKI development was associated with a higher three year mortality rate following both infrarenal and cEVAR (infrarenal EVAR mortality hazard ratio [HR 1.6, 95% confidence interval [CI] 1.01 - 2.7 [p = .046]; cEVAR mortality HR 2.4, 95% CI 1.1 - 5.2 [p = .033]). Following multivariable logistic regression, pre-operative chronic kidney disease (eGFR < 60 mL/min/1.73m2; odds ratio [OR] 2.2, 95% CI 1.03 - 4.8) and neck diameter (OR 1.1, 95% CI 1.01 - 1.2) were significantly associated with AKI following infrarenal EVAR, whereas for cEVAR only contrast volume (OR 1.1, 95% CI 1.0 - 1.2]) was found to be statistically significantly associated with AKI.

CONCLUSION

AKI is a well described complication following infrarenal EVAR and is common after cEVAR. As AKI seems to be associated with permanent renal deterioration and lower survival, efforts to prevent AKI are essential. Future studies are required to assess what factors are associated with a higher risk of developing AKI following cEVAR.

Contemporary incidence, outcomes, and survival associated with endovascular aortic aneurysm repair conversion to open repair among Medicare beneficiaries

OBJECTIVE

The widespread application of endovascular abdominal aortic aneurysm repair (EVAR) has ushered in an era of requisite postoperative surveillance and the potential need for reintervention. The national prevalence and results of EVAR conversion to open repair, however, remain poorly defined. The purpose of this analysis was to define the incidence of open conversion and its associated outcomes.

METHODS

The SVS Vascular Quality Initiative EVAR registry linked to Medicare claims via Vascular Implants Surveillance and Interventional Outcomes Network was queried for open conversions after initial EVAR procedures from 2003 to 2016. Cumulative conversion incidence within up to 5 years after EVAR and outcomes after open intervention were determined. Multivariable logistic regressions were used to identify independent predictors of conversion and mortality.

RESULTS

Among 15,937 EVAR patients, 309 (1.9%) underwent an open conversion: 43% (n = 132) early (<30 days) and 57% (n = 177) late (>30 days). The longitudinally observed rate of conversion was constant over time, as well as by geographic region. Independent predictors of conversion included female sex (hazard ratio [HR], 1.49; P < .001), aneurysm diameter or more than 6.0 cm at the time of index EVAR (HR, 1.74; P < .001), nonelective repair (compared with elective presentation: HR, 1.72; P < .001), and aortouni-iliac repairs (HR, 2.19; P < .001). In contrast, adjunctive operative procedures such as endo-anchors or cuff extensions (HR, 0.62; P = .06) were protective against long-term conversion. Both early (HR, 1.6; P < .001) and late (HR, 1.26; P = .07) open conversions were associated with significant 30-day (total cohort, 15%) and 1-year mortality (total cohort, 25%). Patients undergoing open conversion experienced high rates of 30-day readmission (42%) and cardiac (45%), renal (32%), and pulmonary (30%) complications.

CONCLUSIONS

This large, registry-based analysis is among the first to document the incidence and outcomes for open conversion after EVAR in a national cohort with long-term follow-up. Importantly, women, patients with large aneurysms, and complex anatomy, as well as urgent or emergent EVARs are at an increased risk for open conversion. It seems that more conversions are performed in the early postoperative period, despite perceptions that conversion is a delayed phenomenon. In all instances, conversion is associated with significant morbidity and mortality and highlights the importance of appropriate patient selection at the time of index EVAR.

The Impact of Iliac Artery Anatomy on Distal Landing Zone After EVAR During the 12-Month Follow-Up

BACKGROUND

Proximal sealing zone has been the main interest in endovascular abdominal aortic aneurysm repair (EVAR), although the distal landing zone remodeling may also affect EVAR durability. The aim of this study was to assess iliac anatomy and its potential impact on distal landing zone adverse events after EVAR during the 12-month follow-up.

METHODS

A prospective data collection of patients treated with standard bifurcated EVAR devices for abdominal aortic aneurysm was undertaken between 2017 and 2019. Patients that received extension to the external iliac artery were excluded. Follow-up included computed tomography angiography (CTA) at the 1st and 12th month postoperatively. The common iliac artery (CIA) diameter was assessed in three levels: origin (just below the aortic bifurcation), distally (just above the iliac bifurcation) and the middle of the distance between these two landmarks. Iliac angle, tortuosity indexes, relining and oversizing were also analyzed. Distal landing zone-related adverse events were any limb related re-intervention, endoleak type Ib, graft migration, limb stenosis, or occlusion.

RESULTS

In total, 268 iliac limbs (134 patients) were included. In all three levels, the mean iliac artery diameters increased at 12-month follow-up. At the origin of the CIA, the diameter increased from 18.7 ± 10.5 mm to 19.9 ± 9.4 mm (P = 0.04), at the middle portion of the CIA, the diameter changed significantly from 15.5 ± 5.1 mm to 17.4 ± 5.4 mm (P < 0.001) and at the distal CIA, from 14.6 ± 3.3 mm to 15.1 ± 3.9 mm (P = 0.03). The iliac angle remained stable (P = 0.14) while the CIA index decreased significantly from 1.17 ± 0.13 to 1.11 ± 0.09 (P < 0.001). The mean value of oversizing was 21.5 ± 14.5% and affected distal iliac diameter increase (P < 0.001). The composite outcome of distal landing zone adverse events was not associated to diameter changes at any level. In 57 cases, a distal iliac diameter ≥18 mm was recorded. The estimated oversizing was lower (16.3 ± 11.8%) compared to <18 mm arteries (22.5 ± 14.9%, P = 0.01). At 12-month follow-up, iliac diameters remained stable in the ≥18 mm group. Endoleak type Ib was more common in iliac arteries ≥18 mm [3 (5.3%) vs. 1 (0.5%) (P = 0.04)] at 12-months.

CONCLUSIONS

Post-EVAR iliac artery dilation does not seem to have an impact on distal landing zone adverse events during the 12-month follow-up. Aggressive oversizing may be related to iliac dilation. EVAR patients with iliac arteries ≥18 mm are at higher risk for ET Ib.

Identifying high risk for proximal endograft failure after EVAR in patients suitable for both open and endovascular elective aneurysm repair

INTRODUCTION

Proximal endograft failure (type Ia endoleak or migration) after endovascular aneurysm repair (EVAR) is associated with hostile aneurysm neck morphology. Neck scoring systems were developed to predict proximal endograft failure but were studied in retrospective studies, which due to selection bias may have led to an overestimation of bad outcomes after EVAR. To predict patients who benefit from open repair, preoperative neck morphology and occurrence of long-term proximal endograft failure were investigated in patients enrolled in the endovascular arm of the DREAM-trial who were suitable for open repair by definition and have long-term follow-up.

METHODS

A post-hoc on-treatment analysis of patients after EVAR was performed in 171 patients. Aneurysm neck morphology was quantified using the aneurysm severity grading (ASG)-neck score calculated on pre-operative CT-angiography images. The ASG-neck score was used to predict proximal endograft failure. ROC analysis was performed to calculate a threshold to divide favorable and unfavorable aneurysm necks (low and high-risk), positive and negative likelihood-ratios were calculated accordingly. Freedom from proximal endograft failure was compared between groups using Kaplan Meier analysis.

RESULTS

During a median follow-up of 7.6 years, 20 patients suffered proximal endograft failure. ROC analysis showed an AUC 0.77 (95% CI 0.65-0.90; p<0.001) indicating acceptable prediction. The threshold was determined at ASG-neck score ≥5, 30 patients had unfavorable neck morphology of whom 11 developed proximal endograft failure. The positive likelihood-ratio was 4.4 (95% CI 2.5-7.8) and the negative likelihood-ratio was 0.51 (95% CI 0.3-0.8). Twelve years postoperatively, freedom from proximal endograft failure was 91.7% in favorable and 53.2% in unfavorable groups, difference 38.5% (95% CI 13.9-63.1; p<0.001).

CONCLUSION

In this study, the ASG-neck score predicted proximal endograft failure during the entire follow-up. This exhibits the persistent risk for proximal endograft failure long after EVAR and calls for ongoing surveillance especially in patients with unfavorable aneurysm necks.

Fenestrated EVAR Promotes Positive Infrarenal Neck Remodeling and Greater Sac Shrinkage compared to EVAR

OBJECTIVES

Endovascular aortic aneurysm repair (EVAR) has become the standard of care treatment for abdominal aortic aneurysms (AAA) in the modern era. While numerous devices exist for standard infrarenal AAA repair, fenestrated endovascular aneurysm repair (fEVAR) offers a minimally invasive alternative to traditional open repair in patients with short infrarenal necks. Over time, aortic neck dilation can occur leading to loss of proximal seal, endoleaks, and AAA sac growth. This study analyzes aortic remodeling following EVAR versus fEVAR and further evaluates whether fEVAR confers a benefit in terms of sac shrinkage.

METHODS

A retrospective review of prospectively collected data on 120 patients undergoing EVAR was performed: 30 patients were treated with fEVAR (Cook Zenith© Fenestrated) and 90 patients were treated with EVAR devices (30 with each Medtronic Endurant ©, Gore Excluder ©, and Cook Zenith ©). Demographic data were recorded, and anatomic measurements were taken for each patient pre-operatively, 30 days post-operatively, and at the longest point of follow-up using three-dimensional reconstruction software.

RESULTS

There were no significant differences in demographics data between the 4 groups. fEVAR was used more often in aortas with large necks and irregular morphology (p= 0.004). At the time of longest follow up, the suprarenal aorta encompassing 5, 10, and 15mm above the lowest renal artery (ALRA) dilated the most for fEVAR versus all EVAR groups. Despite this, the infrarenal segment tended to increase by the least, or even regress, for fEVAR compared to all EVAR groups, and was associated with the overall greatest proportion of sac shrinkage for the fEVAR group compared to Medtronic, Gore, and Cook devices, respectively (-13.90% vs. -5.75% vs. -2.31% vs. -4.68%, p=0.025).

CONCLUSIONS

Compared to EVAR, patients treated with fEVAR had greater suprarenal dilation over time, consistent with an overall greater burden of disease in the proximal native aorta. However, the infrarenal segment dilated significantly less over time in the fEVAR group compared to all EVAR groups, suggesting that fEVAR may stabilize the infrarenal neck, promoting positive sac remodeling, as evidenced by the greatest degree of decrease in largest AAA diameter in the fEVAR group.

Supra- and Infra-Renal Aortic Neck Diameter Increase after Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm

Hypovolemia-induced hypotension may lead to an aortic diameter decrease in patients with a ruptured abdominal aortic aneurysm (rAAA). This study investigates the changes in supra- and infra-renal aortic neck diameters before and after endovascular aortic aneurysm repair (EVAR) for rAAA and the possible association with endograft apposition. A retrospective cohort study was conducted including 74 patients treated between 2010 and 2019 in two large European vascular centers. Outer-to-outer wall diameters were measured at +40, +10, 0, −10, and −20 mm relative to the lowest renal artery baseline on the last pre- and first post-EVAR computed tomography angiography (CTA) scan in a vascular workstation. Endograft apposition was determined on the first post-EVAR CTA scan. The post-operative diameter was significantly (p < 0.001) larger than the preoperative diameter at all aortic levels. The aortic diameter at +40 mm (supra-renal) and −10 mm (infra-renal) increased by 6.2 ± 7.3% and 12.6 ± 9.8%, respectively. The aortic diameter at +40 mm increased significantly more in patients with low preoperative systolic blood pressure (<90 mmHg; p = 0.005). A shorter apposition length was associated with a higher aortic diameter increase (R = −0.255; p = 0.032). Hypovolemic-induced hypotension results in a significant decrease in the aortic diameter in patients with an rAAA, which should be taken into account when oversizing the endograft.

Proximal Seal Dilatation following Fenestrated Endovascular Repair for Complex Abdominal Aortic Aneurysms

OBJECTIVES

Although Proximal neck dilatation following infrarenal endovascular aneurysm repair (EVAR) is common and is associated with proximal graft failure, little is known about sealing zone dilatation and its clinical relevance following fenestrated EVAR (FEVAR). We studied proximal seal dilatation (PSD) dynamics following FEVAR and assessed its clinical significance.

METHODS

We included all consecutive patients treated for a juxta-/supra-renal aneurysm with fenestrated EVAR using the Zenith Fenestrated Endovascular Graft (Cook Medical, Bloomington, Ind) from 2008 to 2018 in two large teaching hospitals in the Netherlands. The primary outcome was PSD over time and was determined using a linear mixed-effects model. Secondary outcomes included associations for early PSD and difference in aortic dilatation at the level of the covered-stent compared to the bare-stent. Proximal seal related adverse events were also obtained.

RESULTS

Our cohort included 84 patients with a median CTA follow-up time of 24.5 months [IQR 17-42]. Maximum aneurysm-diameter was 60.1 mm (IQR 56.9-67.2). Mean proximal seal diameter at baseline was 26.2 mm (±2.8), mean stent oversizing was 20.1% (±9.1), and mean proximal seal length was 29.5 mm (±11.7). Proximal seal dilatation of 1.7 mm (95%CI:1.4-2.1) was found in the first year, decelerating thereafter (2^nd-year: 0.9mm/year [95%CI:0.7-1.1]). Over 10% PSD at one year occurred in 22 patients (27%) and was associated with stent-graft oversizing (OR: 1.1 [95%CI:1.03-1.2], p=.008) and a lower number of target vessels (four fenestrations/ref two fenestrations: OR: 0.13 [95%CI:0.02-0.74], p=.029). At last available imaging, dilatation difference was higher at the level of the covered stent compared with the bare stent (3.0mm [IQR 1.3-5.1] vs. 1.6mm [IQR 0.8-2.5], p<.001). During the study period, only one patient (1.2%) developed a proximal seal related-adverse event (type-IA endoleak).

CONCLUSION

PSD is present following FEVAR, occurring at a faster rate in the first year and subsequently decelerating thereafter, similarly to neck dilatation after standard infrarenal EVAR. Although its clinical implication seems to remain limited in the first years following implantation, further research is required to assess the effect of PSD on long-term FEVAR outcomes.

Profile of the Ovation ALTO abdominal stent graft for the treatment of abdominal aortic aneurysms: overview of its safety and efficacy

INTRODUCTION

The Ovation ALTO is the next generation aortic stent graft from Endologix for the treatment of infra-renal abdominal aortic aneurysms. The device uses polymer-injected rings to create a proximal seal at the aneurysm neck.

AREAS COVERED

Results from the first clinical study of the ALTO graft are analyzed and the potential benefits of the graft in minimizing post-treatment aneurysmal neck dilation discussed. The implications of the ALTO's Instructions-For-Use (IFU) and low-profile delivery system are also reviewed.

EXPERT OPINION

The re-positioning of the sealing rings higher on the graft and an integrated compliant balloon are the most significant improvements on the Ovation iX, facilitating accurate placement of the proximal sealing ring and prompt balloon dilation of the polymer rings. The expansion the IFU to include neck lengths of ≥7 mm will mean more patients are eligible for infra-renal EVAR within IFU with the ALTO device. The published data on the device to date is limited. With over 1000 implants worldwide we would hope for more published data to become available. If this demonstrates similar mid-term results to that seen with the Ovation iX in arguably more hostile neck anatomy, then the Ovation ALTO is likely to be more widely used.

Endograft apposition and infrarenal neck enlargement after endovascular aortic aneurysm repair

BACKGROUND

Sufficient apposition and oversizing of the endograft in the aortic neck are both essential for durable endovascular aneurysm repair (EVAR). These measures are however not regularly stated on post-EVAR computed tomography angiography (CTA) scan reports. In this study endograft apposition and neck enlargement (NE) after EVAR with an Endurant II(s) endograft were analyzed and associated with supra- and infrarenal aortic neck morphology.

METHODS

In 97 consecutive elective patients, the aortic neck morphology was measured on the pre-EVAR CTA scan on a 3mensio vascular workstation. The distance between the lowest renal artery and the proximal edge of the fabric (shortest fabric distance, SFD), and the shortest length of circumferential apposition between endograft and aortic wall (shortest apposition length, SAL) was determined on the early post-EVAR CTA scan. NE, defined as the aortic diameter change between pre- and post-EVAR CTA scan, was determined at eight levels: +40, +30, +20, +15, +10, 0, -5 and -10 mm relative to the lowest renal artery baseline. The aortic neck diameter and preoperative oversizing were correlated to NE with the Pearson correlation coefficient. The effective post-EVAR endograft oversizing is calculated from the nominal endograft diameter and the post-EVAR neck diameter where the endograft is circumferentially apposed.

RESULTS

The median time (interquartile range, IQR) between the EVAR procedure and the pre- and post-EVAR CTA scan was 40 (25, 71) days and 36 (30, 46) days, respectively. The Endurant II(s) endograft was deployed with a median (IQR) SFD of 1.0 (0.0, 3.0) mm. The SAL was <10 mm in 9% of patients and significantly influenced by the pre-EVAR aortic neck length (p=0.001), hostile neck shape (p=0.017), and maximum curvature at the suprarenal aorta (p=0.039). The median (interquartile range) SAL was 21.0 (15.0, 27.0) mm with a median (IQR) pre-EVAR infrarenal neck length of 23.5 (13.0, 34.8) mm. The median (IQR) difference between the SAL and neck length was -5.0 (-12.0, 2.8) mm. Significant (p<.001) NE of 1.7 (0.9, 2.5) mm was observed 5 mm below the renal artery baseline, which resulted in an effective post-EVAR endograft oversizing <10% in 43% of the patients. No correlation was found between NE and aortic neck diameter or preoperative oversizing.

CONCLUSIONS

Circumferential apposition between an endograft and the infrarenal aortic neck, SAL, and NE can be derived from standard postoperative CT scans. These variables provide essential information about the post-procedural endograft and aortic neck morphology regardless of the preoperative measurements. Patients with SAL <10 mm or effective oversizing <10% due to NE may benefit from intensified follow-up, but clinical consequences of SAL and NE should be evaluated in future longitudinal studies with longer term follow-up.