Long-term outcomes of endovascular aneurysm repair according to instructions for use adherence status

A Greek Multicentre Study Assessing the Outcome of Late Rupture After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

Late rupture after endovascular aortic aneurysm repair (EVAR) for an abdominal aortic aneurysm (AAA) is an increasing complication associated with a high mortality rate. This study aimed to analyse the causes and outcomes in patients with AAA rupture after EVAR.

METHODS

A multi-institutional Greek study of late ruptures after EVAR between 2008 - 2022 was performed. Primary outcomes were intra-operative and in hospital death.

RESULTS

A total of 70 patients presented with late rupture after EVAR (proportion of ruptured EVARs among all EVARs, 0.6%; 69 males; mean age 77.2 ± 6.7 years). The mean time interval between EVAR and late rupture was 72.3 months (range 6 - 180 months). In all cases the cause of rupture was the presence of an endoleak (type I, 73%) with sac enlargement. Moreover, 34% of subjects with rupture after EVAR had been lost to follow up and 32% underwent a secondary intervention. Additionally, 57 patients (81%) were treated by conversion to open surgical repair (COSR) and the remainder by endovascular correction of endoleak (ECE). Eleven intra-operative deaths (16%) were recorded. The overall in hospital mortality rate was 41% (23% ECE vs. 46% COSR; p = .21). Of the patients who presented as initially haemodynamically stable, 23% died during hospitalisation, while the respective mortality rate for patients who presented as unstable was 78% (odds ratio [OR] 11.8, 95% confidence interval [CI] 3.6 - 39.1; p < .001). Multivariable logistic regression analysis revealed that severity of haemodynamic shock was the most significant risk factor for intra-operative (OR 7.15, 95% CI 1.58 - 32.40; p = .010) and in hospital death (OR 9.53, 95% CI 2.79 - 32.58; p < .001).

CONCLUSION

These data underline the devastating prognosis of late rupture after EVAR. Haemodynamic status at presentation was an important predictive factor for death both in the ECE and COSR groups. Rigorous follow up and prompt evaluation of an unstable patient in case of rupture after EVAR is recommended.

Computed tomography-based automated measurement of abdominal aortic aneurysm using semantic segmentation with active learning

Accurate measurement of abdominal aortic aneurysm is essential for selecting suitable stent-grafts to avoid complications of endovascular aneurysm repair. However, the conventional image-based measurements are inaccurate and time-consuming. We introduce the automated workflow including semantic segmentation with active learning (AL) and measurement using an application programming interface of computer-aided design. 300 patients underwent CT scans, and semantic segmentation for aorta, thrombus, calcification, and vessels was performed in 60-300 cases with AL across five stages using UNETR, SwinUNETR, and nnU-Net consisted of 2D, 3D U-Net, 2D-3D U-Net ensemble, and cascaded 3D U-Net. 7 clinical landmarks were automatically measured for 96 patients. In AL stage 5, 3D U-Net achieved the highest dice similarity coefficient (DSC) with statistically significant differences (p < 0.01) except from the 2D-3D U-Net ensemble and cascade 3D U-Net. SwinUNETR excelled in 95% Hausdorff distance (HD95) with significant differences (p < 0.01) except from UNETR and 3D U-Net. DSC of aorta and calcification were saturated at stage 1 and 4, whereas thrombus and vessels were continuously improved at stage 5. The segmentation time between the manual and AL-corrected segmentation using the best model (3D U-Net) was reduced to 9.51 ± 1.02, 2.09 ± 1.06, 1.07 ± 1.10, and 1.07 ± 0.97 min for the aorta, thrombus, calcification, and vessels, respectively (p < 0.001). All measurement and tortuosity ratio measured - 1.71 ± 6.53 mm and - 0.15 ± 0.25. We developed an automated workflow with semantic segmentation and measurement, demonstrating its efficiency compared to conventional methods.

Mid-term results of "off-label" use of the Endurant stentgraft in patients with infrarenal abdominal aortic aneurysms

OBJECTIVES

EVAR is the preferred treatment modality for patients with an infrarenal abdominal aortic aneurysm with suitable anatomy. Each manufacturer of aortic stentgrafts has specific anatomic requirements. In some patients, it is not possible to adhere to the instructions for use, but alternative treatment is also not possible. In these patients, EVAR can be performed outside instructions for use.

METHODS

In this study, all consecutive patients in whom an Endurant II or IIS stentgraft was used between 1 January and 31 December were reviewed. We compared the two patient groups in whom this stentgrafts was used outside and inside instructions for use. Patients with planned adjuvant therapy, for example, chimney procedure or iliac side branches, were excluded.

RESULTS

In 74 of 178 (41.6%) patients, the instructions for use were not adhered. The main reason was pathology of the aortic neck. There were more patients with type IA endoleak, this difference was borderline significant (p = .06). There were more patients with limb occlusion in the early postoperative period, but at the end of the follow-up period, the incidence was comparable. Aneurysm-related mortality and all-cause mortality were comparable in both groups.

CONCLUSION

In this study, real-life experience with the Endurant II and IIS stentgraft is described. Non-adherence with instructions for use was associated with a higher risk of endoleak type IA (p = .06). In the early postoperative period, there were more patients with limb occlusion; this finding was not observed anymore at the end of the follow-up period.

Reducing aneurysm sac growth and secondary interventions following endovascular abdominal aortic aneurysm repair by preemptive coil embolization of the inferior mesenteric artery and lumbar arteries

OBJECTIVE

Type II endoleak (EL-2) is the most common complication following endovascular aneurysm repair (EVAR), leading to continued sac growth and potential rupture. In this study, we examined the association between patency of the inferior mesenteric artery (IMA) and lumbar arteries (LAs) with respect to sac growth. The effect of preemptive embolization of the IMA and/or LAs on the need for secondary interventions for sac growth post-EVAR was also evaluated.

METHODS

A retrospective cohort study was performed on consecutive patients who underwent EVAR for non-ruptured, infrarenal abdominal aortic aneurysms (AAAs) from January 2012 to December 2020. A select group of patients underwent preemptive embolization of the IMA and/or LA. Patients with any types I, III, or IV endoleaks were excluded. Patency of the IMA and LA on preoperative computed tomography angiogram (CTA) was evaluated on TeraRecon workstation. All secondary interventions to treat EL-2 were recorded. Sac growth was defined as centerline axial diameter increase of ≥5 mm on follow-up CTA.

RESULTS

A total of 300 patients (mean age, 74 ± 8.5 years; 83.7% male) underwent EVAR. Ninety-nine patients had preemptive embolization of the IMA and/or LA. Mean follow-up of the cohort was 59.3 ± 30.5 months. Thirty-six patients (12%) demonstrated sac growth on follow-up; 12 of these (33.3%) had preemptive embolization. The median time until detection of sac growth was 28.8 months (interquartile range, 15.2-46.5 months), with a mean growth of 10.1 ± 6.4 mm. Sac growth was significantly associated with presence of EL-2: 27 of 36 (75%) with EL-2 vs 9 of 36 (25%) without EL-2 (P < .001). Patients with sac growth had a higher mean total number (2.6 ± 1.5) of patent lower LAs (L3, L4) compared with those without (2.0 ± 1.4; P = .03). Patency of L1, L2, and L3 LAs were not associated with sac growth. However, patency of at least one L4 LA was significantly associated with sac growth (14.8% vs 7.7%; P = .04). The highest incidence of sac growth (17.6%) was seen when both IMA and L4 LA were patent; significantly different from the lowest incidence (5.3%) when both were occluded preoperatively (P = .018). Preemptive coiling of the IMA and/or LA significantly reduced the need for post-EVAR secondary intervention for sac growth. Freedom from post-EVAR secondary intervention was achieved in 92 of 99 (92.9%) pre-EVAR coiled patients vs 163 of 201 (81.5%) patients who did not undergo pre-EVAR coiling (P = .009).

CONCLUSIONS

Preemptive coil embolization of the IMA and LAs, especially L4 LA, reduces the need for secondary interventions for sac growth, potentially improving the long-term durability of EVAR.

Long-Term Outcomes of Endovascular Repair Within and Outside the Instructions for Use in Korean Patients With Abdominal Aortic Aneurysm

OBJECTIVE

Endovascular aneurysm repair (EVAR) has been used worldwide to treat abdominal aortic aneurysms (AAAs). Outcomes after EVAR within and outside the instruction for use (IFU) remain controversial. We analyzed long-term outcomes of EVAR within-the-IFU compared with that outside-the-IFU and baseline clinical/anatomical characteristics that influence outcomes of EVAR.

METHODS

The study included 546 patients who underwent EVAR for infrarenal AAA from 1997 to 2021 at 2 Korean medical centers. The primary endpoint was graft-related adverse events (GRAEs), including type 1 or 3 endoleak, reintervention (included open conversion), aneurysm sac enlargement, aneurysm-related mortality (ARM), rupture, stent-graft migration, and stent thrombotic occlusion.

RESULTS

The patients who underwent EVAR outside the IFU were 287 (52.6%). A neck angle of >60° was most common outside the IFU criteria (n=146, 50.9%). This study revealed that patients outside the IFU had a higher rate of GRAEs compared with patients within the IFU (hazard ratio [HR]: 1.879; 95% confidence interval [CI]: 1.045-2.386). A neck angle of >60° was a significant risk factor for GRAEs (adjusted HR: 2.229; 95% CI: 1.418-3.503), type 1 or 3 endoleak (adjusted HR: 2.640; 95% CI: 1.343-5.189), and reintervention (adjusted HR: 1.891; 95% CI: 1.055-3.388).

CONCLUSIONS

Our study revealed EVAR with outside the IFU was associated with increased GRAEs, mainly attributed to endoleak and ARM, compared with EVAR with within the IFU. In addition, severe neck angulation was an independent risk factor for GRAEs, type 1 or 3 endoleak, and reintervention.

CLINICAL IMPACT

Our study revealed endovascular aneurysm repair (EVAR) with outside-the-instruction for use (IFU) was associated with increased graft-related adverse events (GRAEs) compared with EVAR with within-the-IFU. In the low-risk population, the incidence of GRAEs and Aneurysm related mortality were higher in the outside-the-IFU group rather than within-the-IFU group. In addition, severe neck angulation was an independent risk factor for GRAEs, type 1 or 3 endoleak and reintervention.

Possible implications of device-specific variability in post-endovascular aneurysm repair sac regression and endoleaks for surveillance categorization

OBJECTIVE

Significant sac regression during early surveillance has been shown to best predict reintervention-free long-term surveillance after endovascular aneurysm repair (EVAR). Furthermore, a persistent endoleak has been related to a worse outcome. Individualized surveillance algorithms based on these findings have been suggested. There are no studies comparing the performance of different stent grafts regarding sac regression, the presence of type II endoleaks, and their possible implications for individualized surveillance. The objective of this study was to evaluate device-specific differences and how these may affect patient categorization for surveillance.

METHODS

Patients were treated electively with standard EVAR between 2005 and 2015 using three different devices (Zenith by Cook, Excluder by Gore, and Endurant by Medtronic). The data were reviewed retrospectively until 2020. Patients' computed tomography angiographies (CTAs) at 30 days and at 2 years were analyzed for freedom from endoleaks and for sac regression of ≥5 mm. Reinterventions during long-term surveillance were counted. Patients were categorized according to the presence of any endoleak and sac regression at 30 days and 2 years, and the probability of reintervention-free long-term surveillance was evaluated based on these findings.

RESULTS

A total of 435 patients were treated for an abdominal aortic aneurysm with EVAR during the study period. At 30 days, 80.0% (n = 339) of the patients were free from endoleaks, and at 2 years, 78.9% (n = 273) were free from endoleaks. There was a significant difference in endoleak rate at 30 days and 2 years between the devices (P < .001 and P = .001). There was no significant difference in sac regression between the devices at 2 years (P = .096). The categorization at 30 days based on endoleak status had a sensitivity of 44.9%, specificity of 87.4%, and negative predictive value of 84.1% for finding a reintervention-requiring complication during long-term follow-up. The corresponding figures at 2 years were 63.3%, 91.4%, and 89.4%, respectively. The combination of freedom from endoleaks and sac regression of ≥5 mm in the 2-year CTA best predicted an uneventful long-term surveillance. Patients who met this criterion had a 95.6% probability (negative predictive value) of having a reintervention-free long-term surveillance.

CONCLUSIONS

There are significant differences in the prevalence of endoleaks between devices at 30 days and 2 years, but there is no difference in sac regression. Patients with sac regression of ≥5 mm and no endoleaks in the 2-year CTA can be safely categorized for infrequent surveillance regardless of the stent graft model that has initially been used.

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

Objective

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

Methods

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

Results

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

Conclusion

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

The Effect of Age on Peri-Operative Outcomes after FEVAR

INTRODUCTION

Fenestrated endovascular aortic repair (FEVAR) has become a popular custom-made treatment option for juxtarenal and pararenal aneurysms. It has been previously investigated whether octogenarians as a distinct subgroup are at increased risk for adverse outcomes after FEVAR. With diverging results and an inconclusive understanding of age as a risk factor in general, an analysis of the historical data of a single center was conducted to add to the available body of evidence and further investigate the effect of age as a continuous risk factor.

METHODS

A retrospective data analysis of a prospectively maintained single-center database of all patients who underwent FEVAR at a single department of vascular surgery was performed. The main endpoint was post-operative survival. In addition to association analyses, potential confounders such as co-morbidities, complication rates, or aneurysm diameter were examined. In terms of sensitivity analyses, logistic regression models were created for the dependent variables of interest.

RESULTS

During the observation period from April 2013 to November 2020, 40 patients over the age of 80 and 191 patients under the age of 80 were treated by FEVAR. The 30-day survival showed no significant difference between the groups (95.1% in octogenarians and 94.3% in patients under 80 years of age). The sensitivity analyses conducted also showed no difference between the two groups, and complication and technical success rates were comparable. The aneurysm diameter was 67 ± 13 mm in the study group and 61 ± 15 mm in those under 80 years of age. Additionally, the sensitivity analyses showed that age as a continuous variable exhibits no effect on the outcomes of interest.

DISCUSSION

In the present study, age was not associated with adverse peri-operative outcomes after FEVAR, including mortality, lower technical success rates, complications, or length of hospital stay. Essentially, the most highly associated factor with hospital and ICU length of stay was time spent in surgery. However, octogenarians had a significantly larger aortic diameter at the time of treatment, which might indicate the potential introduction of bias by pre-interventional patient selection. Nevertheless, the usefulness of research on octogenarians as a distinct subgroup might be questionable regarding the scalability of results, and future studies might focus on age as a continuous risk factor instead.

Hybrid Surgical Technique for Open AAA Repair in the Setting of Severe Iliac Artery Calcification

In the present report, we describe the case of a patient with an infrarenal abdominal aortic aneurysm that had been incidentally noted on an imaging study. Treatment decisions for this case were complicated by the presence of a hostile infrarenal aortic neck and significant bilateral iliac artery circumferential calcification, precluding iliac artery clamping and standard distal anastomotic techniques. We performed a hybrid surgical procedure, deploying bilateral iliac stent grafts into the distal aneurysmal aorta and sewing our aortic graft to the proximal extent of these stents. The findings from the present case add to the previously reported techniques of hybrid surgical management of abdominal aortic aneurysms with iliac disease and expand the technique to a larger application.

Endovascular Repair of Abdominal Aortic Aneurysms is a Valid Alternative to Open Repair also in Patients Treated Outside of Instructions for Use Criteria

Purpose

It remains unclear whether endovascular aneurysm repair, in the long term, is less effective than open surgery due to need for reinterventions and close monitoring. We aimed to evaluate this matter in a real-life cohort.

Methods

We collected consecutive patients treated with EVAR or OSR between January 2005 and December 2013. Primary outcomes were 30-day, 90-day and long-term all-cause mortality. Secondary outcomes were 30-day reintervention rate and reintervention-free survival. We evaluated also a subpopulation who did not adhere to IFU.

Results

The inclusion criteria were met by 416 patients. 258 (62%) received EVAR, while 158 (38%) underwent OSR. The 30- or 90-day mortality was similar between groups (p = 0.272 and p = 0.346), as ARM (p = 0.652). The 30-day reintervention rate was higher in the OSR group (p < 0.001), but during follow-up, it was significantly higher in the EVAR group (log-rank: 0.026).

There were 114 (44.2%) non-IFU patients in the EVAR group, and we compared them with OSR group. There was no significant difference in all-cause mortality at 30 or 90 days, nor in the long term (p = 1; p = 1 and p = 0.062). ARM was not affected by the procedure technique (p = 0.136). The short-term reintervention rate was higher in the OSR group (p = 0.003), while in the long-term EVAR, patients experienced more reinterventions (log-rank = 0.0.43).

Conclusion

No significant difference in survival was found between EVAR and OSR, independent of adherence to IFU. EVAR may be considered for surgical candidates.