Proximal Endoleak Research Articles

Prediction of Late Proximal Endoleak Risk after EVAR by Preoperative Estimation of Endograft/Aortic Neck Apposition Surface

The aim of this study was to evaluate a new measurement tool for the pre-operative computed tomography (CT) scan to estimate the endograft apposition surface on the proximal aortic neck of the aneurysm that would predict the risk of late type IA endoleak (EL1A). From databases of four high-volume centres, between 2004 and 2020 all patients who underwent EVAR with the possibility of analysing pre- and post-EVAR scans and who presented late (>2 years) EL1A in follow-up were included retrospectively (EL1A group). A control group of randomly selected EL1A-free patients were included (control group) and follow-up beyond four years. The measurement tool (Endosize®, Therenva) was used to model a virtual cylinder constrained by the centreline whose diameter was determined from the diameter of the implanted endograft. The apposition surface was calculated by determining the areas of the virtual cylinder mesh outside the mesh of the neighbouring portion of the segmented aorta by an intersection calculation of surface normals. This apposition surface and the usual anatomical data of the proximal neck were compared between the groups with univariate and multivariate analyses. Intra- and inter-observer variability in the measurement of apposition surface was analyzed using the intraclass correlation coefficient (ICC) and the method of Bland and Altman. Sixty-six comparable patients were included, 33 in the EL1A group and 33 in the control group. The mean time to EL1A onset was 50.2 ± 24.6 months in the EL1A group and the mean follow-up time was 79.8 ± 26.8 months in the control group. In univariate analysis, only the endograft apposition surface ratio on the proximal neck was significantly lower in the EL1A group compared with the control group (50.3% vs. 75.5%; p <0.0001). There was no significant difference in classic anatomical neck characteristics. There was no difference in proximal endograft oversizing or in the length from the lowest renal artery to the beginning of the covered portion of the endograft. In multivariate analysis, only the apposition surface ratio was independently correlated with the presence of EL1A (p <0.0001). The estimation of the intra- and inter-observer variability, indicates excellent reliability (ICC = 0.992; ICC = 0.956). The method estimating the pre-operative endograft apposition surface on the proximal aortic neck appears to be a reliable measuring in predicting the risk of occurrence of late EL1A after EVAR.

A biomechanical analysis of novel endovascular implants for aortic valve replacement and ascending aortic repair

Advances in medical technology have enabled minimally invasive treatment of type A aortic dissection with accompanying aortic regurgitation. Implants include endovascular stent grafts (ESG) and heart valve substitute (HVS) modules. Traditional implants can be divided into two types based on the assembly relationship between ESG and HVS: separated z-shaped implants (SZ) and separated diamond-shaped implants (SD). This study proposes a novel linked diamond-shaped implant (LD). To evaluate the safety and effectiveness of this new implant, finite element simulation models were created to assess the risks of endoleak, migration, and vascular wall rupture under annulus displacement load. After the SZ, SD, and LD implants were grafted in virtual release method, all the implants can cover tear-entry located in the ascending aorta, but space distance (δ) which exposed to blood was 14.5, 13.1, and 7.4 mm, respectively; the maximum areas of contact gap was 76.5, 51.5 and 6.3 mm2; the maximum migration distance (ΔL1) were 1.27, 1.06, and 0.1 mm; the maximum stress on ascending aorta was 0.19, 0.24, and 0.51 MPa, which were lower than failure stress (0.9 MPa). This study showed that both SZ and SD implants had minimal effects on the ascending aorta; however, higher risks were associated with implant migration and proximal endoleak. In contrast, the LD implant can simplify the surgical procedure, has a lower risk of endoleak and migration, and limited stress stimulation of the aorta. This study validated the feasibility and effectiveness of this novel implant using the finite element method, indicating its potential as a secure and reliable treatment option.

Comparison of bare and nonbare stent grafts during thoracic endovascular aneurysm repair of the aortic arch

ObjectiveWe compared the outcomes of patients treated with nonbare stents (NBS) and proximal bare stents (PBS) endografts with a proximal landing zone in the aortic arch during thoracic endovascular aortic repair (TEVAR). MethodsWe conducted a retrospective cohort, observational, multicenter study that included 361 consecutive TEVAR procedures undertaken between November 2005 and December 2021. TEVAR patients with both BS and NBS Relay stent graft configurations with proximal landing in zones 1, 2, or 3 were enrolled. Preoperative anamnestic and morphological data, clinical outcomes, and aortic modifications 30 days after surgery and at the latest follow-up available were collected. The primary outcome was freedom from proximal endoleak (type IA) comparing the two configurations. Total and detailed endoleak rates, clinical and technical success, intraoperative additional maneuvers, major adverse events, and reinterventions were secondary outcomes. ResultsThe median follow-up was 4.9 (interquartile range, 2.0-8.1) years. No statistically significant difference between NBS and PBS patients concerning 30-day major adverse events, retrograde aortic dissection, disabling stroke, or late type IA endoleak (10.8% vs 7.8%; P = .597). Aneurysmal disease (P = .026), PLZ diameter of >34 mm (P = .026), aortic tortuosity index of >1.4 (P = .008), type III aortic arch (P = .068), and PLZ thrombus (P = .014) identified as risk factors by univariate Cox regression analysis. PLZ thrombus was the only type IA endoleak risk factor at multivariate Cox regression (P = .016). ConclusionsWe found no statistically significant difference in freedom from type IA endoleak, retrograde dissection, or disabling stroke observed between the NBS and the BS configuration of the Relay endograft. Proximal landing zone thrombotic apposition was a prominent risk factor for type IA endoleak after TEVAR.

Computational prediction of proximal sealing in endovascular abdominal aortic aneurysm repair with unfavorable necks

Background and ObjectiveEndovascular aortic aneurysm repair (EVAR) has become the standard treatment for abdominal aortic aneurysms in most centers. However, proximal sealing complications leading to endoleaks and migrations sometimes occur, particularly in unfavorable aortic anatomies and are strongly dependent on biomechanical interactions between the aortic wall and the endograft. The objective of the present work is to develop and validate a computational patient-specific model that can accurately predict these complications. MethodsBased on pre-operative CT-scans, we developed finite element models of the aorta of 10 patients who underwent endovascular aortic aneurysm repair, 7 with standard morphologies and 3 with unfavorable anatomies. We simulated the deployment of stent grafts in each aorta by solving mechanical equilibrium with a virtual shell method. Eventually we compared the actual stent ring positions from post-operative computed-tomography-scans with the predicted simulated positions. ResultsA successful deployment simulation could be performed for each patient. Relative radial, transverse and longitudinal deviations were 6.3 ± 4.4%, 2.5 ± 0.9 mm and 1.4 ± 1.1 mm, respectively. ConclusionsThe numerical model predicted accurately stent-graft positions in the aortic neck of 10 patients, even in complex anatomies. This shows the potential of computer simulation to anticipate possible proximal endoleak complications before EVAR interventions.

A modified aortic arch "island anastomosis" with stent graft technique for acute type A aortic dissection: a retrospective analysis.

A modified aortic arch "island anastomosis" with a stent graft technique was used in 33 patients with acute type A aortic dissection. We retrospectively reviewed our experience of this procedure and the short-term follow-up results. This retrospective analysis included 33 patients with acute type A aortic dissection undergoing the modified aortic arch island anastomosis with stent graft procedure. Postoperatively, computed tomography angiography images were obtained before discharge and at 12 months. All patients underwent successful surgery without intraoperative death. Three patients received dialysis because of postoperative renal insufficiency, 1 patient received tracheotomy because of postoperative respiratory insufficiency, and 5 patients had postoperative delirium. Surgery caused stroke in 1 patient. No paraplegia was found, and no re-exploration for bleeding was performed. One patient died in the hospital due to multiple organ failure, and the other patients were discharged as expected. Only 1 patient had a proximal endoleak, and the patient was stable under close follow-up. The diameter of the descending thoracic aorta was smaller at 12 months postoperatively than preoperatively (34.5±2.5 mm versus 36.7±2.9 mm, P<0.05). The average diameter of the true lumen of the descending thoracic aorta was larger at 12 months postoperatively than preoperatively (24.1±3.1 mm versus 14.9±2.3 mm, P<0.05). The modified aortic arch island anastomosis with stent graft technique is a feasible and safety surgical strategy for acute type A aortic dissection. Short-term outcomes are satisfactory.

Early Institutional Experience with One-Piece Bifurcated-Fenestrated Stentgraft in the Treatment of Abdominal Aortic Aneurysms

Purpose: To review the early experience of the use of a bifurcated-fenestrated endograft (Bif-FEVAR) to treat abdominal aortic aneurysms (AAA) in a high-volume aortic center. Methods: A retrospective single-center analysis was conducted between March 2019 and April 2021 including consecutive patients that underwent Bif-FEVAR. Only patients without a proper infrarenal neck and a distance <70 mm between the lowest target artery and the native or prosthetic aortic bifurcation were considered. All Bif-FEVAR custom-made devices were manufactured by Cook Medical (Inc., Bloomington, Indiana). Demographics, anatomical features, technical success, major adverse events, 30-day mortality, and survival according to Kaplan–Meier were analyzed according to Society for Vascular Surgery standards. Results: Overall, 10 patients (100% male with median age 78) were included. The median preoperative maximal aneurysm diameter was 68 mm [51–84]. Eight patients were treated for a proximal type I endoleak after endovascular aneurysm repair. A total of 36 fenestrations were planned. The median operative time was 144 min [127–168], with a median fluoro time of 40.5 min [34–54] and a median dose area product of 73 Gy cm2 [61–89]. Technical success rate was 100%. No patients experienced a major postoperative adverse event. Median follow-up time was 8 months [6–13]. Conclusion: Bif-FEVAR is technically feasible when there is a short distance below the lowest target artery and the aortic bifurcation, with favorable short-term results. Clinical Impact This study assessed the use of an innovative one-piece bifurcated fenestrated stent-graft as a primary procedure or in the treatment of proximal endoleak after standard infrarenal EVAR. We demonstrated these custom-made devices can be used safely with favorable short-term results. One-piece bifurcated fenestrated stent-grafts extend the indications of FEVAR for patients with an unusually short distance between the lowest renal artery and the aorto-iliac bifurcation or the diverter flow of a preexisting bifurcated infrarenal stent-graft.

Chimney Stenting Versus Surgical Debranching for the Treatment of Aortic Arch Pathologies—A Propensity-Matched Analysis

Endovascular repair of aortic arch lesions requires revascularization of epiaortic vessels in case of coverage. The objective of this study was to compare the outcomes of surgical bypass versus endovascular reconstruction with a chimney graft. A retrospective analysis of a multicenter register between January 2005 and December 2019 was performed. A total of 127 patients were included and divided into 2 groups: thoracic endovascular aortic repair+surgical debranching (n=72) and thoracic endovascular aortic repair+chimney stenting (n=55). The main end points were major neurologic sequelae and type IA endoleak. Propensity score matching was performed to analyse baseline variables related to these outcomes. The mean follow-up was 35.6months for the debranching group and 34.1 for the chimney group (P=0.65). The incidence of stroke was higher in the chimney group although not statistically significant (7.3% vs. 4.1%; P=0.46); for both groups, a wide angle between the ostium of the target vessel and the aorta and landing in Ishimaru Zone 0 was found to be the main predictors for major neurologic sequelae (P=0.002 and P=0.003, respectively). During follow-up, 9 (12.5%) type IA endoleaks occurred in the debranching group and 12 (21.8%) in the chimney group (P=0.14). Aortic diameter larger than 66mm and arch angle >46° had a strong association with proximal endoleak incidence (P=0.001 and P=0.011, respectively) CONCLUSIONS: Surgical debranching showed better results than chimney stenting in terms of major neurologic events incidence and type IA endoleak, although the difference between the groups was not statistically significant. Further research with larger cohorts is needed to establish the indications for these procedures.

Prediction of the risk of proximal endoleak after EVAR by preoperative estimate of the stentgraft/aortic neck surface of contact

Despite the compliance with the anatomical recommendations on the proximal neck, type 1a endoleaks (EL1A) may occur after EVAR and their correction is complex. The objective of this study was to evaluate a new measuring instrument obtained from the preoperative CT by estimating the surface of apposition of the stentgraft on the proximal neck of the aneurysm, which would allow predicting the risk of EL1A.

Fenestrated Aortic Aneurysm Repair in Patients Treated Inside Versus Outside of Instructions for Use

Objectives: The aim of this study was to compare outcomes of patients treated with the Cook Zenith Fenestrated (ZFEN) device for juxtarenal aortic aneurysms inside versus outside the IFU. Methods: We retrospectively reviewed our institutional ZFEN database for cases performed between 2012 and 2018, with analysis performed in 2020 in order to report midterm outcomes. The cohort was stratified based on treatment inside (IFU group) and outside (non-IFU group) the IFU for criteria involving the proximal neck: neck length 4 to 14 mm, neck diameter 19 to 31 mm, and neck angulation ≤45°. Patients with thoracoabdominal aneurysms or concurrent chimney grafting were excluded. The primary outcomes in question were mortality, type 1a endoleak, and reintervention. Univariate and multivariate analyses were performed to determine associations between adherence to IFU criteria and outcomes. Results: We identified 100 consecutive patients (19% female, mean age 73.6 years) for inclusion in this analysis. Mean follow-up was 21.6 months. Fifty-four patients (54%) were treated outside the IFU because of inadequate neck length (n=48), enlarged neck diameter (n=10), and/or excessive angulation (n=16). Eighteen patients were outside IFU for two criteria, and one patient was outside IFU for all three. Non-IFU patients were exposed to higher radiation doses (3652 vs 5445 mGy, p=0.008) and contrast volume (76 vs 95 mL, p=0.004). No difference was noted between IFU and non-IFU groups for 30-day mortality (0% vs 3.7%, p=0.18), or type 1a endoleak (0% vs 1.9%, p=0.41). Reintervention was also similar between cohorts (13% vs 27.8%, p=0.13). Being outside IFU for neck diameter or length was each borderline significant for higher reintervention on univariate analysis (p=0.05), but this was not significant on multivariate Cox proportional hazard modeling (HR 1.82 [0.53–6.25]; 2.03 [0.68–7.89]), respectively. No individual IFU deviations were associated with the primary outcomes on multivariate analysis, nor being outside IFU for multiple criteria. Conclusions: Patients with juxtarenal aortic aneurysms may be treated with the ZFEN device with moderate deviations from the IFU. While no differences were seen in mortality or proximal endoleak, larger studies are needed to examine the potential association between IFU nonadherence and reinterventions and close follow-up is warranted for all patients undergoing such repair.

Late Type 1A Endoleaks: Associated Factors, Prognosis and Management Strategies

Unlike periprocedural Type 1A endoleaks, late appearing proximal endoleaks have been poorly described. We studied all elective EVAR from 2010 -2018 in a single institution. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late Type 1A endoleaks and survival. Of 477 EVAR during the study period, 411 (86%) had follow-up imaging, revealing 24 Type 1A endoleaks; 4 early and 20 late. Freedom from Type 1A endoleaks was 99%, 92-81% at 1, 5 and 8 years with a median time to occurrence of 2.5 years (.01-8.2 years). On completion angiogram, only 10% of patients with a late Type 1A had a proximal endoleak, and 60% had no endoleak. Only 21% of late Type 1As were diagnosed on routine 1-year CT angiogram, but 79% had stable or expanding sacs. Two thirds (65%) of the patients eventually diagnosed with late Type 1A endoleaks had previously been treated for other endoleaks, mostly Type 2 (10/13). Age (HR 1.07/year [1.02-1.12], P=0.01), neck diameter >28mm (HR 3.5 [1.2-10.3], P=0.02), neck length <20mm (HR 3.0 [1.1-8.6], P=0.04), and neck angle>60 degrees (HR 3.4 [1.5-7.9], P=0.004) were associated with higher rates of Type 1A endoleak, but not female sex, endograft, or the use of suprarenal fixation. 2 patients had proximal degeneration and 5 experienced graft migration. There were 2 ruptures (10%), and 13 patients underwent repair with 5 open conversions. Median survival after late Type 1A repair was 6.6 years (0-8.4 years). Late appearing Type 1A endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful surveillance is needed in patients with hostile neck anatomy and those who undergo intervention for other endoleaks. Adverse neck anatomy may be better suited for open repair or fenestrated/branched devices rather than conventional EVAR.

Editor's Choice – Four Fenestration Endovascular Aortic Aneurysm Repair Without Stenting of the Coeliac Artery in Selected Cases

Editor's Choice – Four Fenestration Endovascular Aortic Aneurysm Repair Without Stenting of the Coeliac Artery in Selected Cases

Funnel technique for wide infrarenal aneurysm neck with Lifetech Ankura™ Stent Graft System.

Background In this study, we present our mid-term results in patients undergoing treatment with the funnel technique and describe technical issues for this bailout technique in extra-wide infrarenal necks. Methods Between January 2018 and June 2020, a total of seven male, symptomatic patients (median: 74.5 years; range, 64 to 84 years) who had comorbidities and were in the American Society for Anesthesiologists Class IV and treated by the funnel technique in an endovascular fashion were included. Pre- and post-procedural data of the patients, early mortality and technical success rates were evaluated. Results There was no early mortality. Technical success rate was 100%. There was no type I or III endoleaks at the completion angiography. All patients were discharged without any problem on the second or third day of the procedure. The median follow-up was 13 (range, 6 to 28) months. The aneurysm sac shrinkage was achieved in all patients over six months of follow up. During the follow-up period, no proximal endoleak or infrarenal aortic neck diameter enlargement was found. Conclusion Based on our limited experience, the funnel technique may be considered more than a bailout procedure under special circumstances.

Long-term outcomes of the conformable TAG thoracic endoprosthesis in a prospective multicenter trial

BackgroundThe Gore conformable TAG thoracic endoprosthesis (CTAG) was engineered to enhance conformability in the thoracic aorta and has demonstrated greater deployment accuracy and wall apposition than the original TAG device. The Food and Drug Administration approved the CTAG in 2011 based on the 1-year results of the pivotal trial for the CTAG device. In the present report, we have documented the outcomes for those patients through 5 years. MethodsThe CTAG aneurysm study was a prospective, multicenter trial that assessed the safety and effectiveness of the CTAG device as treatment of descending thoracic aortic aneurysms. Follow-up imaging assessments consisted of radiographs and computed tomography at annual intervals through 5 years. A core imaging laboratory was used to assess the aneurysm size, device integrity, and endoleaks. ResultsA total of 66 patients were enrolled (51 pivotal arm patients and 15 continued access patients) from October 2009 through September 2011. The baseline characteristics, procedural characteristics, and outcomes through 2 years were reported previously. Through 5 years, five patients (7.6%) had required device-related reintervention (one type Ia endoleak or contained rupture of the descending thoracic aorta, one type Ib endoleak, two indeterminate endoleaks, and one thoracic aortic pseudoaneurysm). Four patients (6.1%) had died of aneurysm-related causes, with one death occurring within 30 days of the index procedure. A total of 24 patients (36.3%) had died during the 5-year study period. Seven patients (10.6%) had experienced stroke or transient ischemic attack through 5 years, with one early stroke (postoperative day 28). Prosthesis or intercomponent migration was observed in six patients (9.1%) through 5 years; however, no patient had developed a type III junctional endoleak. No stent-graft fracture or compression was observed through 5 years. At 5 years, 14 patients (50.0%) showed sac regression, 5 (17.9%) showed sac expansion, and 9 (32.1%) showed sac stability using on a 5-mm threshold for change. ConclusionsThoracic endovascular aortic repair with the CTAG device was associated with low rates of aneurysm-related mortality and reintervention through 5 years. Proximal endoleak was rare, and most patients showed sac regression or stability at 5 years after the initial thoracic endovascular aortic repair.

FDG PET/CT in infected abdominal aortic aneurysm due to Brucellosis

A 66-year-old man with a history of aortic aneurysm, treated 5 years before by endovascular aneurysm repair (EVAR), underwent a follow-up CT angiography showing an increased aneurysm size to 64 mm, a proximal endoleak, and an inflammatory thickening of the aneurysm wall. The patient did not have fever or abdominal pain. Laboratory tests showed a normal blood count, a slightly elevated C-reactive protein and a normal procalcitonin.

Management of Nellix migration and type Ia endoleak from proximal endovascular aneurysm sealing relining to late open conversion

BackgroundDespite promising early results, midterm failures of the Nellix endovascular aneurysm sealing (EVAS) system (Endologix Inc, Irvine, Calif) have been reported at higher than expected rates. The management of proximal endoleaks and migration differs from those after conventional endovascular aortic aneurysm repair (EVAR) owing to the peculiar design of the Nellix device. In the present study, we report a monocentric experience in the management of EVAS complications using various techniques. We also performed a comprehensive review of the relevant literature on both open surgical and endovascular management of proximal failure of EVAS from the MEDLINE database. MethodsWe retrospectively analyzed the reinterventions for type Ia endoleak and migration after elective infrarenal EVAS at our institution. We collected preoperative, intraoperative, and follow-up data. Open and endovascular techniques are described. Overall survival, aortic-related mortality, and the technical success rate (rate of exclusion of endoleaks) with endovascular techniques were the primary outcomes. ResultsWe performed 101 infrarenal elective EVAS procedures from 2013 to 2018. Of the 101 patients, 20 (19.8%) had required reintervention for proximal sealing failure. The indications were type Ia (Is2, Is3) endoleak, migration >5 mm, sac expansion >5 mm, and secondary rupture. Of the 20 patients, 6 (30%) were treated with endovascular techniques—2 with a chimney Nellix-in-Nellix application and 4 with proximal relining with a covered stent. The remaining 14 patients (70%) were treated with late open conversion (OC). The average time from EVAS to reintervention was 36.1 months (range, 3-65 months). Six patients (30%) had undergone OC in an emergent setting because of secondary rupture. The technical success rate for the patients treated with endovascular reinterventions was 100%. The 30-day mortality was 20% (4 of 20), all emergent cases (four of six emergent repairs; 67%). The overall survival for the 20 patients was 75% (n = 15) at a mean follow-up of 15.1 months (range, 2-47 months). One patient had died after 7 months of non–aortic-related causes. ConclusionsThe high reintervention rate of the Nellix graft mandates careful evaluation for its further use with the revised instructions for use, and it should not be used off-label. OC remains the strategy of choice when managing Nellix proximal sealing failures in fit patients. Chimney Nellix-in-Nellix application and transcatheter embolization are feasible alternative techniques. Proximal relining also appears to be an effective alternative to more complex interventions, although it requires further studies for validation.

Endovascular aortic repair with EndoAnchors demonstrate good mid-term outcomes in physician-initiated multicenter analysis-The PERU registry.

We aim to describe real-world outcomes from multicenter data about the efficacy of adjunct Heli-FX EndoAnchor usage in preventing or repairing failures during infrarenal endovascular aneurysm repair (EVAR), so-called EndoSutured-aneurysm-repair (ESAR). The current study has been assigned an identifier (NCT04100499) at the US National Library of Medicine (https://ClinicalTrials.gov). It is an observational retrospective study of prospectively collected data from seven vascular surgery departments between June 2010 and December 2019. Patients included in the ANCHOR registry were excluded from this analysis. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. Follow-up imaging was scheduled according to each center's protocol, which necessarily included either abdominal ultrasound or radiography or computed tomographic scan imaging. The main outcomes analyzed were technical success, freedom from type Ia endoleaks (IaEL), all-cause and aneurysm-related mortality, and sac variation and trends evaluated for those with at least six months imaging follow-up. Two hundred and seventy-five patients underwent ESAR in participating centers during the study period. After exclusions, 221 patients (184 males, 37 females, mean age 75 ± 8.3 years) were finally included for analysis. Median follow-up for the cohort was 27 (interquartile range 12-48) months. A median 6 (interquartile range 3) EndoAnchors were deployed at ESAR, 175 (79%) procedures were primary and 46 (21%) revision cases, 40 associated with type IaEL. Technical success at operation (initial), 30-day, and overall success were 89, 95.5, and 96.8%, respectively; the 30-day success was higher due to those with subsequent spontaneous proximal endoleak seal. At two years, freedom from type IaEL was 94% for the whole series; 96% and 86% for the primary and revision groups, respectively; whereas freedom from all-cause mortality, aneurysm-related mortality, and reintervention was 89%, 98%, and 87%, respectively. Sac evolution pre-ESAR was 66 ± 15.1 vs. post ESAR 61 ± 17.5 (p < 0.001) and for 180 patients with at least six-month follow-up, 92.2% of them being in a stable (51%) or regression (41%) situation. This real-world registry demonstrates that adjunct EndoAnchor usage at EVAR achieves high rates of freedom from type IaEL at mid-term including in a high number of patients with hostile neck anatomy, with positive trends in sac-size evolution. Further data with longer follow-up may help to establish EndoAnchor usage as a routine adjunct to EVAR, especially in hostile necks.

Factors affecting the occurrence of proximal endoleak after endovascular abdominal aortic repair for abdominal aneurysms.

ObjectiveThis retrospective study was performed to assess the clinical and radiological variables associated with proximal type IA endoleak (EL) in patients treated with elective endovascular repair for abdominal aortic aneurysms.MethodsThe chi-square test, t-test, and logistic regression analysis were performed as appropriate. A P value of <0.05 was considered statistically significant.ResultsThe data of 79 patients were analyzed. No mortality occurred. During follow-up (median, 28.5 months; interquartile range, 12.8–43.0 months), 10 patients developed type IA EL. In the logistic regression analysis, undersizing of the endograft diameter by <10% significantly affected the occurrence of type IA EL. When the diameter was used for measurements, less oversizing was significantly associated with a higher risk of type IA EL. When the area was used for measurements, oversizing of >20% significantly affected the occurrence of type IA EL.ConclusionWhen sizing endografts, a discrepancy was noted between the measurements of the diameter and area of the proximal neck. The area might represent a more accurate measurement than the axial diameter to optimize the proximal sealing and lower the risk of developing type IA EL.

Natural History of Late Type IA Endoleaks

Although early type IA endoleaks are well described, late-appearing proximal endoleaks are less understood. All patients who underwent elective endovascular aneurysm repair without prior aortic surgery at a single institution from 2010 to 2018 were studied. Only type IA endoleaks diagnosed on postoperative computed tomography scans were considered, not completion angiograms. Late endoleaks were defined as those appearing after 1 year. We used Cox regression to study factors associated with late type IA endoleaks. There were 477 patients who underwent endovascular aneurysm repair, of whom 411 (86%) had adequate follow-up. There were 24 type IA endoleaks, 4 early and 20 late. The freedom from type IA endoleaks was 99%, 92%, and 81% at 1 year, 5 years, and 8 years, with a median time to occurrence of 2.5 years (3 days-8.2 years). Only 40% of patients with type IA endoleaks were treated within the initial graft instructions for use. Although 75% of the early type IA endoleaks appeared on completion angiography, only 10% of patients with a late type IA endoleak had a proximal endoleak on completion angiography, and 60% had no endoleak at the completion of the index case. Only 21% of late type IA endoleaks were evident by 1 year, but 79% had stable or expanding sacs. Twelve (60%) late type IA endoleaks had prior interventions for other endoleaks, mostly type II (10/12). Age (hazard ratio [HR], 1.07 per year [1.02-1.12]; P = .01), neck diameter >28 mm (HR, 3.5 [1.2-10.3]; P = .02), neck length <20 mm (HR, 3.0 [1.1-8.6]; P = .04), and neck angle >60 degrees (HR, 3.4 [1.5-7.9]; P = .004) were all independently associated with higher rates of type IA endoleak, but not female sex, endograft, or the use of suprarenal fixation. Two patients had proximal degeneration and five experienced graft migration. There were two ruptures (10%), and 14 patients underwent repair (5 open, 9 endovascular), 3 of whom underwent multiple interventions. Median survival after late type IA endoleak repair was 6.6 years (0-8.4 years). Late-appearing type IA endoleaks have a high rate of rupture and present significant diagnostic and management challenges. Careful follow-up is needed, especially in patients with hostile neck anatomy and those undergoing intervention for other endoleaks.

Quantification of suprarenal aortic neck dilation after fenestrated endovascular aneurysm repair

ObjectiveSuprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) with commercially available devices has not yet been well characterized. The aim of this study was to measure diameter changes in the supravisceral aorta after FEVAR. MethodsThis is a single-center retrospective review involving patients with juxtarenal aneurysms treated with Cook ZFEN devices (Cook Medical, Bloomington, Ind). Patients with at least 1 year of cross-sectional radiologic follow-up were included. AND was defined as ≥3 mm at any measured location. Aortic diameter, defined as the average outer to outer diameter on three-dimensional centerline imaging, was measured at seven locations along the length of the ZFEN device from the proximal fixation struts to the bottom of the second seal stent. The first postoperative CT scan (≤1 month) served as a baseline from which subsequent measurements at annual intervals were compared. ResultsA total of 43 patients who underwent FEVAR from 2012 to 2018 met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Mean follow-up time was 30.3 months. Any AND was found to occur in 32 (74.4%) patients. Aortic diameter dilation at latest follow-up was found to occur at all measured locations from the top of the fixation struts (1.9 ± 2.4 mm; P < .0001) to the middle of the second seal stent (1.3 ± 3.8 mm; P < .01). Diameter growth was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm. At this location, the aorta experienced nearly linear annual growth of 0.99 mm (95% confidence interval, 0.7-1.28 mm) per year. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of postoperative neck diameter growth (1.34 mm per 10% increase in oversizing; P = .02), whereas increasing proximal seal length was protective of growth (−1.82 mm per 10-mm increase in seal length; P = .016). Proximal seal lengths ≥3 cm were associated with less neck dilation compared with <3 cm (2.6 mm vs 4.9 mm; P = .022). Type IA endoleak in this cohort was rare (n = 1) and not associated with AND (P = .256). ConclusionsDilation of the suprarenal aorta is a common finding in midterm follow-up after FEVAR and not associated with proximal endoleak. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone. These results support the continued use of FEVAR for juxtarenal aneurysms, particularly in patients in whom ≥3 cm of healthy seal length can be obtained.

Maximizing proximal seal zone in fenestrated endografting: Evolution in the approach to graft configuration

ObjectiveFenestrated endografting for juxtarenal and pararenal abdominal aortic aneurysms affords the ability to seal stent grafts in normal aorta at and above the renal arteries. The Zenith fenestrated graft (ZFEN; Cook Medical, Bloomington, Ind) is custom-made to surgeon specifications, subject to certain manufacturing limitations. The most common configuration in the pivotal trial and in commercial use after approval has been as a scallop for the superior mesenteric artery (SMA) and two small fenestrations for the renal arteries (configuration A). An alternative configuration to maximize the seal zone length, consisting of a large fenestration for the SMA and two small fenestrations for the renal arteries (configuration B) has been routinely adopted at our institutions to potentially prevent type IA endoleak. MethodsThe present retrospective cohort study examined 100 consecutive ZFEN grafts designed for patients at two university centers from 2012 through 2019. The proximal seal length, measured from the top of the graft to the beginning of the aneurysm, was determined from the preoperative computed tomography angiograms. Alternative configurations were evaluated to determine whether they would have provided a longer proximal seal length. ResultsThe two most common configurations were B (n = 45) and A (n = 38). For the cases in which A had been chosen but B could have been built, 5.8 ± 1.9 mm of seal zone length was lost. For the cases in which B was chosen but A could have been built, 5.8 ± 2.8 mm of seal zone length was gained. Owing, in part, to the increased proximal seal length with configuration B, this configuration has been used more frequently in the past 4 years of the present study compared with the first four (53% vs 25%; P = .004). Of 95 patients who had completed surgery and follow-up, type IA endoleaks were observed in 12 (13%) on completion angiography, all of which had resolved on follow-up imaging without intervention. No SMA was compromised by misalignment of the large fenestration in configuration B. ConclusionsA significantly longer proximal seal length can be obtained using a ZFEN with a large fenestration for the SMA and two small fenestrations for the renal arteries. Whenever possible, surgeons should consider this configuration to maximize the proximal seal length and potentially reduce the risk of proximal endoleak. An additional advantage of this approach is that stenting of the SMA to prevent shuttering will be unnecessary or impossible, making the procedure more technically facile.