Incidence and Risk Factors for Sac Expansion after Endovascular Aneurysm Repair of Abdominal Aortic Aneurysms

Effects of Pre-emptive Aortic Side Branch Embolization on Early-Stage Type II Endoleaks and Sac Changes After Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

Purpose

This study evaluated the effect of pre-emptive embolization of the aortic side branches on the short-term incidence of type II endoleaks (T2ELs) and aneurysm sac changes following endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs).

Materials and Methods

Data of 157 patients with degenerative large AAAs (≥50 mm for males and ≥45 mm for females) treated between January 2019 and October 2024 were retrospectively analyzed. The patients were categorized into the pre-emptive embolization (n=30, 19.1%) and non-embolization (n=127) groups. Embolization was considered for patients with high-risk factors for T2EL, specifically an inferior mesenteric artery (IMA) diameter ≥3 mm and a large lumbar artery diameter. Outcomes were assessed 1 month and 1 year postoperatively. The primary outcome was T2EL incidence, and the secondary outcomes were changes in aneurysm size and reintervention rates.

Results

At 1 month postoperatively, T2EL incidence was significantly lower in the embolization group (3.3%, 1/30) than in the non-embolization group (22.8%, 29/127) (P=0.015). At 1 year postoperatively, the T2EL incidence was 8.0% (2/25) in the embolization group and 23.0% (23/100) in the non-embolization group, although the difference was not statistically significant (P=0.094). Sac expansion was absent in the embolization group, whereas 4.0% of patients in the non-embolization group experienced expansion (P=0.583). Subgroup analysis for 37 patients with patent IMA ≥3 mm showed a significantly lower T2EL incidence at 1 month (5.6% vs. 52.6%, P=0.002) and 1 year (12.5% vs. 52.9%, P=0.014) postoperatively in the embolization group. Additionally, sac shrinkage was higher in the embolization group than in the non-embolization group (56.2% vs. 23.5%, P=0.055). Multivariable analysis confirmed pre-emptive embolization as an independent protective factor for T2EL at 1 year postoperatively (odds ratio 0.071, 95% confidence interval, 0.008-0.663; P=0.020).

Conclusion

Pre-emptive embolization reduced the incidence of early T2EL after EVAR and showed stable outcomes at the 1-year follow-up, particularly in patients with large patent IMA diameters.

Validation of the Vascular Study Group of New England (VSGNE) risk prediction model for abdominal aortic aneurysm repair in Korea: a single-center retrospective study

Purpose

The Vascular Study Group of New England (VSGNE) risk prediction model is a simple method for estimating risk for elective abdominal aortic aneurysm (AAA) repair. The model considers both treatment methods and the physical characteristics of the aneurysm type as well as comorbidities. This research aimed to validate its effectiveness by analyzing retrospective data on Korean patients.

Methods

Our single-center retrospective analysis included 1,227 patients who underwent elective open repair surgery (ORS) or endovascular aortic repair (EVAR) from 2005 to 2021. We assessed the discrimination of the risk score and the effects of several risk factors.

Results

Most patients (66.7%) were classified as low risk in the model, with only 5.6% considered high risk. The mean risk score was 2.81, significantly lower than reported in previous studies. The actual 30-day mortality was only 0.7%, less than the predicted 1.1%. The accuracy of the model in predicting 30-day mortality was statistically significant (area under the curve, 0.822). Patients with high scores were associated with significantly increased mortality (odds ratio, 3.9; P < 0.001). Factors such as advanced age, cerebrovascular disease, and elevated creatinine levels were influential in mortality outcomes. However, a significant difference was not found in short-term mortality between ORS and EVAR.

Conclusion

Although the VSGNE model is an objective tool for assessing death risk in elective AAA repair, the actual risk scores in our patient population were lower than predicted. To create a more representative tool for the Korean population, we suggest developing a novel model based on multicenter data collection.

Identifying Patients at High Risk for Post-EVAR Aneurysm Sac Growth

PURPOSE

Post-EVAR (endovascular aneurysm repair) aneurysm sac growth can be seen as therapy failure as it is a risk factor for post-EVAR aneurysm rupture. This study sought to identify preoperative patient predictors for developing post-EVAR aneurysm sac growth.

MATERIAL AND METHODS

A systematic review was conducted to select potential predictive preoperative factors for post-EVAR sac growth (including a total of 34.886 patients), which were evaluated by a retrospective single-center analysis of patients undergoing EVAR between 2009 and 2019 (N=247) with pre-EVAR computed tomography scans and at least 1 year follow-up. The primary study outcome was post-EVAR abdominal aortic aneurysm (AAA) sac enlargement (≥5 mm diameter increase). Multivariate Cox regression and Kaplan-Meier survival curves were constructed.

RESULTS

Potential correlative factors for post-EVAR sac growth included in the cohort analysis were age, sex, anticoagulants, antiplatelets, renal insufficiency, anemia, low thrombocyte count, pulmonary comorbidities, aneurysm diameter, neck diameter, neck angle, neck length, configuration of intraluminal thrombus, common iliac artery diameter, the number of patent lumbar arteries, and a patent inferior mesenteric artery. Multivariate analysis showed that infrarenal neck angulation (hazard ratio, 1.014; confidence interval (CI), 1.001-1.026; p=0.034) and the number of patent lumbar arteries (hazard ratio, 1.340; CI, 1.131-1.588; p<0.001) were associated with post-EVAR growth. Difference in estimated freedom from post-EVAR sac growth for patients with ≥4 patent lumbar arteries versus <4 patent lumbar arteries became clear after 2 years: 88.5% versus 100%, respectively (p<0.001). Of note, 31% of the patients (n=51) with ≥4 patent lumbar arteries (n=167) developed post-EVAR sac growth. In our cohort, the median maximum AAA diameter was 57 mm (interquartile range [IQR] = 54-62) and the median postoperative follow-up time was 54 months (IQR = 34-79). In all, 23% (n=57) of the patients suffered from post-EVAR growth. The median time for post-EVAR growth was 37 months (IQR = 24-63). In 46 of the 57 post-EVAR growth cases (81%), an endoleak was observed; 2.4% (n=6) of the patients suffered from post-EVAR rupture. The total mortality in the cohort was 24% (n=60); 4% (n=10) was AAA related.

CONCLUSIONS

This study showed that having 4 or more patent lumbar arteries is an important predictive factor for postoperative sac growth in patients undergoing EVAR.

CLINICAL IMPACT

This study strongly suggests that having 4 or more patent lumbar arteries should be included in preoperative counseling for EVAR, in conjunction to the instructions for use (IFU).

Endotension Following Endovascular Aneurysm Repair: Retrospective Review of Treatment and Clinical Outcome

Purpose

: Endotension is a rare late complication characterized by an increase in sac size without any type of endoleak following endovascular aortic aneurysm repair (EVAR). Due to its rarity, few studies have demonstrated the mechanism behind and the management of endotension. In this study, we aimed to better understand the treatment and the long-term outcome of endotension in a single-center cohort.

Materials and Methods

: This study was designed for a retrospective review of the patients diagnosed with endotension between January 2006 and December 2017. The study patients were categorized into two groups (primary versus secondary) based on the presence of any type of endoleak before the diagnosis of endotension. We collected data related to endotension treatment, intraoperative findings, and long-term outcomes.

Results

: In a cohort of 15 patients diagnosed with endotension following EVAR, eight were classified into the primary endotension (PE) group without prior endoleak, and seven exhibited secondary endotension (SE). Among the eight PE patients, endovascular intervention for a preemptive purpose was conducted in six patients; however, three (50%) showed continuous sac expansion and finally received open conversion. Overall, eight patients (five in PE and three in SE) underwent open conversion, and one (12.5%) presented with an undetected endoleak during the operative findings. Postoperative morbidity was observed in three patients with no operative mortality.

Conclusion

: Endotension can be managed initially through simple observation for changes on serial images, along with preemptive endovascular intervention. However, surgical intervention should be considered for patients with specific indications including continuous aneurysm sac enlargement, presence of symptoms, suspicions of migration of stent-graft with endoleak, and infection.

Novel Strategies for the Hostile Iliac Artery during Endovascular Aortic Aneurysm Repair

Successful endovascular aneurysm repair can be achieved with favorable aortic and iliac arterial anatomies. However, patients with challenging iliac anatomy, such as stenotic, calcified, tortuous arteries, or concomitant iliac artery aneurysms, are commonly encountered. Such a hostile iliac anatomy increases the risk of intraprocedural complications and worsens long-term outcomes. This review addresses various technical options for treating patients with a hostile iliac anatomy, including innovative endovascular solutions, physician-modified endografts, and hybrid procedures. These considerations demonstrate the wide scope of therapies that may be offered to patients with an unfavorable iliac anatomy.

Mid-term outcomes of hypogastric artery embolization in endovascular aneurysm repair: a case series

Hypogastric artery embolization is performed during endovascular aneurysm repair (EVAR) involving the common iliac artery. Within this case series, we have observed elevated rates of sac expansion subsequent to this intervention. April 2009 to March 2021, 22 patients underwent EVAR with hypogastric artery embolization. We evaluated the mid-term outcomes for these patients. The mean follow-up period was 57 months. We achieved a 100% technical success rate without open conversion and no hospital deaths. The rates of freedom from aneurysm expansion at 1, 3, and 5 years were 90.5%, 59.1%, and 37.5%, respectively. The percentage of sac expansion exceeding 5 mm was 54.5% (12/22). Combined endovascular aortic aneurysm repair and embolization of the hypogastric artery might be associated with a high rate of remote sac expansion. Larger trials are needed to verify risks and benefits.

[Late Open Semi-conversion with Endograft Preservation for (Type II) Endoleaks with Late Aneurysm Sac Enlargement after EVAR - Indications, Method and Results in Our Own Patient Collective]

EVAR (endovascular aortic repair) is the most common method for treating an abdominal aortic aneurysm, but according to the latest findings it carries the risk of subsequent complications. These can be caused by (late) aneurysm sac growth. If conservative and surgical therapies fail to treat the aneurysm sac growth, open conversion is necessary to prevent aneurysm rupture. There are several options for open conversion, in which the EVAR prosthesis can be completely preserved or is (partially) removed. Late open semi-conversion with complete in-situ preservation of the EVAR-prosthesis and gathering of the aneurysm sac are a less invasive method than complete conversion and may be performed instead for selected patients. The aim of the present work is to present the surgical method, including indications and technical information, as well as the presentation of the results in our recent patient collective.All patients semi-converted in our department of vascular surgery and phlebology due to (type II) endoleak were included. All data are presented as n (%) or median (range).Between 6/2019 and 3/2023, 13 patients underwent semi-conversion 6 (2-12) years (median, range) after the initial EVAR. The aneurysm sac diameter at the time of semi-conversion was 69 mm (58-95 mm), the operating time was 114 min (97-147 min), the blood loss was 100 ml (100-1500 ml). Five (38%) patients received blood transfusion intraoperatively and 2 (15%) postoperatively. The stay in the intensive care unit lasted 1 (1-5) days, the hospitalisation time was 8 (6-11) days. Postoperative complications were intestinal atony (3 [23%], 1 [8%] with nausea/emesis and gastric tube insertion), anaemia (2 [15%]), hyponatraemia (2 [15%]), delirium (1 [8%]), COVID-19 infection (1 [8%]) and 1 [8%] intra-abdominal postoperative bleeding with the indication for surgical revision and the transfusion of 8 erythrocyte concentrates.Semi-conversion is a safe and practicable surgical method with few severe complications for a selected group of patients, which should be considered as an alternative to more invasive methods with (partial) removal of the EVAR-prosthesis. Further long-term studies comparing semi-conversion to full conversion are needed to demonstrate its benefits.

Predictors of Abdominal Aortic Aneurysm Shrinkage after Endovascular Repair

Recent studies demonstrate that patients with a shrinking abdominal aortic aneurysm (AAA), one-year after endovascular repair (EVAR), have better long-term outcomes than patients with a stable AAA. It is not known what factors determine whether an AAA will shrink or not. In this study, a range of parameters was investigated to identify their use in differentiating patients that will develop a shrinking AAA from those with a stable AAA one-year after EVAR. Hundred-seventy-four patients (67 shrinking AAA, 107 stable AAA) who underwent elective, infrarenal EVAR were enrolled between 2011-2018. Long-term survival was significantly better in patients with a shrinking AAA, compared to those with a stable AAA (p = 0.038). Larger preoperative maximum AAA diameter was associated with an increased likelihood of developing AAA shrinkage one-year after EVAR-whereas older age and larger preoperative infrarenal β angle were associated with a reduced likelihood of AAA shrinkage. However, this multivariate logistic regression model was only able to correctly identify 66.7% of patients with AAA shrinkage from the total cohort. This is not sufficient for implementation in clinical care, and therefore future research is recommended to dive deeper into AAA anatomy, and explore potential predictors using artificial intelligence and radiomics.