Aneurysm Sac Thrombus Volume Predicts Aneurysm Expansion with Type II Endoleak After Endovascular Aneurysm Repair

Two-Stage Endovascular Aneurysm Repair with Preemptive Embolization: A Retrospective Study

BACKGROUND

Type II endoleak is the most common complication of endovascular aneurysm repair. Retrograde perfusion from the aneurysmal sac side branch to the aneurysmal sac, including the inferior mesenteric artery and lumbar arteries, is associated with adverse events after endovascular aneurysm repair, such as aneurysm sac enlargement, reintervention, rupture, and abdominal aortic aneurysm-related death. Preemptive embolization of the aneurysmal sac side branch before endovascular aneurysm repair is an effective and safe procedure for preventing type II endoleak and reducing the size of the aneurysmal sac. Since 2019, we have been conducting preemptive embolization of the inferior mesenteric artery and lumbar arteries. Thus, we intended to work on a two-stage endovascular aneurysm repair in which embolization and endovascular aneurysm repair are performed on separate days, owing to concerns about prolonged operative time and increased contrast media use and radiation exposure from performing endovascular aneurysm repair simultaneously. This study aimed to evaluate the effects of a two-stage endovascular aneurysm repair.

METHODS

This retrospective study included 114 cases of endovascular aneurysm repair (95 men and 19 women) for AAA performed at our hospital between January 2019 and December 2022. Inferior mesenteric artery and lumbar artery embolization were performed simultaneously with endovascular aneurysm repair (simultaneous group) in 49 cases, and two-stage embolization was performed (two-stage group) in 30 cases. The primary endpoints included the occurrence of T2EL during follow-up and the embolization rate of the IMA or LAs.

RESULTS

Type II endoleak did not occur in the two-stage group (follow-up period: 35 ± 6.2 months), whereas it was observed in 8.2% of patients more than 6 months after EVAR in the simultaneous group (follow-up period: 28 ± 5.5 months). While the total operative time was 340 ± 111.2 min in the simultaneous group, the durations for embolization and endovascular aneurysm repair in the two-stage group were 169 ± 35.5 min and 135.0 ± 26.4 min (total time 304 ± 31.2 min, P = 0.21), respectively, indicating a reduction in the total time required for the 2 techniques. The total amounts of contrast media used in the simultaneous and two-stage groups were 200.0 ± 179.2 mL and 182.0 ± 51.2 mL (P = 0.42), respectively, and the corresponding total radiation doses were 2502.4 ± 690.5 mGy and 2114.6 ± 351.2 mGy (P = 0.28), respectively, showing a decrease in both in the two-stage group. The lumbar artery embolization rates were 74.3% and 87.9% (P < 0.01) in the simultaneous and two-stage groups, respectively, indicating a significant difference.

CONCLUSIONS

Two-stage endovascular aneurysm repair with preemptive embolization of the inferior mesenteric artery and lumbar arteries may be an effective strategy for reducing type II endoleak occurrence, overall operative time, contrast use, and overall radiation exposure.

Surgical Treatment for Sac Expansion Caused by Type II Endoleaks after Endovascular Aneurysm Repair of Abdominal Aortic Aneurysms/Iliac Aneurysms

BACKGROUND

This study aimed to examine the outcomes of open surgery techniques involving sacotomy and suturing of the feeding vessels in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR).

METHODS

Fourteen consecutive patients treated with sacotomy and suturing of feeding vessels for expanding aneurysm sacs with type II endoleaks following EVAR, between January 2018 and December 2022, were retrospectively included. All patients underwent preoperative digital subtraction angiography, and attempts were made to embolize the thick feeding vessels to reduce intraoperative bleeding. Age, sex, comorbidities, clinical presentation, aneurysm sac increase, morbidity, mortality, and follow-up were recorded.

RESULTS

The median age of the patients was 72.89 ± 5.13 years old, and 13 (92.9%) patients were male. The sac size at the time of the open procedure was 107.89 ± 22.58 mm, and the extent of sac growth at the time of the open procedure was 37.50 ± 18.29 mm. The initial technical success rate of laparotomy and open ligation of the culprit arteries causing type II endoleaks was 92.9% (13/14). Among the patients, 5 (35.7%) had been treated with interventional embolization before the open procedure. One endograft was removed and replaced by a bifurcated Dacron graft because of distal dislocation in one patient. All patients recovered, and no deaths were recorded postoperatively. No patients had an eventful postoperative course or any subsequent graft-related complications during follow-up.

CONCLUSIONS

Open surgical repair involving sacotomy and suturing of the feeding vessels appeared to have good outcomes in the treatment of patients with aneurysm sac expansion caused by type II endoleaks after EVAR. Preoperative embolization of feeding vessels can thus effectively reduce intraoperative bleeding.

Patent iliolumbar artery increase no risk of type II endoleaks after endovascular abdominal aortic aneurysm: a case-control study

Objective

The aims of the present study were to explore the risk factors for type 2 endoleaks (T2ELs) after endovascular aneurysm repair (EVAR) and the association between T2ELs and the iliolumbar artery.

Materials and methods

A single-center, retrospective case-control study in West China Hospital was conducted among patients with infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between June 2010 and June 2019. The associations of patient characteristics, anatomical factors, internal iliac artery embolization, and ILA with the primary outcome were analyzed. The secondary objective was to analyze survival and reintervention between the T2EL group and the non-T2EL group. Kaplan-Meier survival, propensity matching analysis and multivariate logistic regression analysis were used.

Results

A total of 603 patients were included. The median follow-up was 51 months (range 5.0-106.0). There was a significant difference in the diameter of the lumbar artery (LA), middle sacral artery (MSA) and inferior mesentery artery (IMA), proportion of thrombus and LA numbers. The univariate analysis showed that T2ELs were more likely to develop more thrombus in aneurysm cavity (OR = 0.294, p = 0.012), larger MSA (OR = 1.284, p = 0.04), LA (OR = 1.520, p = 0.015), IMA (OR = 1.056, p < 0.001) and more LAs (OR = 1.390, p = 0.019). The multivariate analysis showed that the number of LAs (HR: 1.349, 95% CI: 1.140-1.595, p < .001) and the diameter of the IMA (HR: 1.328, 95% CI: 1.078-1.636, p = 0.008) were significantly associated with T2ELs. There were no new findings from the propensity score matching. The reintervention-free survival rates were significantly different between the two groups (p = 0.048). Overall survival and AAA-related death rates were not different between the two group. This was consistent with the PSM analysis.

Conclusion

The iliolumbar artery and the different internal iliac artery interventions may not increase the incidence of T2ELs. But the numbers of LAs and IMA diameter were independent risk factors for T2Els. T2ELs was associated with the reintervention but did not affect long-term survival or increase aneurysm-related mortality after EVAR.

The Association Between the D-dimer Level at 1 Year After EVAR and Sac Diameter Change in Patients With Persistent Type 2 Endoleak

PURPOSE

Recent studies suggested that continuous clotting renewal in thrombi plays a central role in sac enlargement after endovascular aneurysm repair (EVAR). We reviewed patients with persistent type 2 endoleak (T2EL) to estimate the impact of D-dimer level on sac enlargement.

METHODS

A retrospective review of elective EVAR for infrarenal abdominal aortic aneurysm performed between June 2007 and February 2020. Persistent T2EL was defined as T2EL confirmed at both the 6 and 12 month contrast-enhanced computed tomography (CECT) follow-ups. "Isolated" T2EL was defined as T2EL without other types of endoleak within 12 months. Patients with >2 year follow-up, persistent isolated T2ELs, and D-dimer level data at 1 year (DD1Y) were included. Patients with any reintervention within 12 months were excluded. The association between DD1Y and aneurysm enlargement (AnE), defined as a ≥5 mm diameter increase, within 5 years was analyzed. Among 761 conventional EVAR, 515 patients had >2 years of follow-up. Thirty-three patients with any reintervention within 12 months and 127 patients without CECT at either 6 or 12 months were excluded. Among 131 patients with persistent isolated T2ELs, 74 patients with DD1Y data were enrolled. During a 37 month median follow-up [25-60, IQR], 24 AnEs were observed. In the AnE patients, the median DD1Y was significantly higher than that in the other patients (12.30 [6.88-21.90] vs 7.62 [4.41-13.00], P=0.024). ROC curve analysis indicated that the optimal cutoff point of DD1Y for AnE was 5.5 µg/mL (AUC=0.681). In univariate analysis, angulated neck, occlusion of the inferior mesenteric artery, and DD1Y≥5.5 µg/mL were significantly associated with AnE (P= 0.037, 0.038, and 0.010). Cox regression analysis revealed that DD1Y≥5.5 µg/mL was correlated with AnE (P=0.042, HR [95% CI] 4.520 [1.056-19.349]).

CONCLUSION

A 1 year higher D-dimer level can potentially predict AnE within 5 years in persistent T2EL patients. AnE was considered improbable when the D-dimer level was low enough.

CLINICAL IMPACT

The present study suggests that a 1-year higher D-dimer level could potentially predict aneurysm expansion within 5 years in patients with persistent type 2 endoleak (T2EL). On the other hand, aneurysm expansion was considered unlikely if the D-dimer level was low enough.As there are many patients with T2EL who require regular follow-up, any predictor of future aneurysm expansion could be of great help in conserving medical resources. In patients with a low likelihood of future expansion, we might consider delaying follow-up, similar to patients with sac shrinkage.

Development and Comparison of Multimodal Models for Preoperative Prediction of Outcomes After Endovascular Aneurysm Repair

Objective

The aim of this study was to develop and compare multimodal models for predicting outcomes after endovascular abdominal aortic aneurysm repair (EVAR) based on morphological, deep learning (DL), and radiomic features.

Methods

We retrospectively reviewed 979 patients (January 2010—December 2019) with infrarenal abdominal aortic aneurysms (AAAs) who underwent elective EVAR procedures. A total of 486 patients (January 2010–December 2015) were used for morphological feature model development and optimization. Univariable and multivariable analyses were conducted to determine significant morphological features of EVAR-related severe adverse events (SAEs) and to build a morphological feature model based on different machine learning algorithms. Subsequently, to develop the morphological feature model more easily and better compare with other modal models, 340 patients of AAA with intraluminal thrombosis (ILT) were used for automatic segmentation of ILT based on deep convolutional neural networks (DCNNs). Notably, 493 patients (January 2016–December 2019) were used for the development and comparison of multimodal models (optimized morphological feature, DL, and radiomic models). Of note, 80% of patients were classified as the training set and 20% of patients were classified as the test set. The area under the curve (AUC) was used to evaluate the predictive abilities of different modal models.

Results

The mean age of the patients was 69.9 years, the mean follow-up was 54 months, and 307 (31.4%) patients experienced SAEs. Statistical analysis revealed that short neck, angulated neck, conical neck, ILT, ILT percentage ≥51.6%, luminal calcification, double iliac sign, and common iliac artery index ≥1.255 were associated with SAEs. The morphological feature model based on the support vector machine had a better predictive performance with an AUC of 0.76, an accuracy of 0.76, and an F1 score of 0.82. Our DCNN model achieved a mean intersection over union score of more than 90.78% for the segmentation of ILT and AAA aortic lumen. The multimodal model result showed that the radiomic model based on logistics regression had better predictive performance (AUC 0.93, accuracy 0.86, and F1 score 0.91) than the optimized morphological feature model (AUC 0.62, accuracy 0.69, and F1 score 0.81) and the DL model (AUC 0.82, accuracy 0.85, and F1 score 0.89).

Conclusion

The radiomic model has better predictive performance for patient status after EVAR. The morphological feature model and DL model have their own advantages and could also be used to predict outcomes after EVAR.

Positive association between calcium channel blocker treatment and persistent type II endoleak

BACKGROUND

Type II endoleaks are the most common complication occuring after endovascular abdominal aortic aneurysm repair (EVAR). The aim of our study was to evaluate the impact of persistent type II endoleak on sac dynamics post-EVAR, and to study the association between non-anatomical factors including polymorphisms associated with abdominal aortic aneurysm (AAA) and persistent type II endoleak.

METHODS

The cohort comprises of 210 patients undergoing EVAR between January, 2010 and December, 2018. A persistent type II endoleak was defined as any type II endoleak lasting longer than six months and included also a type II endoleak diagnosed after six months or more post-EVAR during the 36-month follow-up period confirmed with CT-angiography. Anteroposterior AAA maximum diameter and AAA volume were measured pre-EVAR and 36 months post-EVAR using CT-angiographic pictures. Sac progression was defined as at least 5 mm increase, sac regression as at least 5 mm decrease in the sac diameter in relation to the preprocedural diameter. Sociodemographic information, comorbidities, treatment, laboratory parameters, selected anatomical and genetic factors were all analysed to determine their impact on persistent type II endoleak. The adjustments included age, hypertension, diabetes mellitus, dyslipidaemia, sex, smoking in multivariate analyses. When postprocedural diameter and volume were evaluated, adjustments included also preprocedural diameter/volume.

RESULTS

After exclusion, 178 pacients with mean age 72.4±7.60 years remained for analysis. Persistent type II endoleak was found in 27.5% of patients (n=49) and 2.94-times increased risk of sac progression in multivariate analysis (p=0.033). In multivariate analysis, AAA diameter in patients with persistent type II endoleak was 4.31 mm greater than in patients without (B=4.31; p=0.014); and its presence was also associated with 22.0 cm³ greater sac volume (B=22.0; p=0.034) compared to patients without persistent type II endoleak. Treatment with calcium channel blockers increased risk of persistent type II endoleak 2.11-times in multivariate analysis (OR 2.11; 95% CI 1.05-4.25; p=0.037). No association between persistent type II endoleak and selected polymorphisms associated with AAA and other observed factors was found.

CONCLUSIONS

Risk of persistent type II endoleak was more than doubled in patients taking calcium channel blockers. Patients with persistent type II endoleak had greater anteroposterior sac diameter and sac volume compared to patients without persistent type II endoleak.

Persisting Type 2 Endoleaks Following EVAR for AAA Are Associated With AAA Expansion

PURPOSE

To determine the evolution of abdominal aortic aneurysm (AAA) diameter in the presence of persisting type 2 endoleaks (pEL2) following endovascular abdominal aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

This is a retrospective, single-center, case-control study. All patients with pEL2 (pEL2 group, persisting for > 12 months) between 2004 and 2018 were identified and compared with a 1:1 age- and gender-matched control with no endoleak (control group). Primary outcome measures were freedom from AAA expansion and freedom from AAA shrinkage over time. AAA diameter measurements were performed on computed tomography angiography (CTA). Secondary outcome measures were survival, AAA-related mortality, reinterventions for pEL2, incidence of secondary type 1 endoleaks (EL1), and infrarenal aortic branch vessel anatomy.

RESULTS

A total of 773 patients were treated with EVAR for AAA between 2004 and 2018. Of them, 286 patients demonstrated type 2 endoleaks (EL2) in postoperative CTA or intraoperative angiography (37%). Forty-five of 286 EL2 (15.7%) were pEL2 (pEL2 group). Freedom from AAA expansion in the pEL2 group was 100%, 96.7%, 85.2%, and 54.3% after 1, 2, 3, and 4 years, respectively, compared with 100% after 1, 2, 3, and 4 years in the control group (p<0.01). Freedom from AAA shrinkage in the pEL2 group after 1, 2, 3, and 4 years was 95.5%, 90.4%, 90.4%, and 79.1%, respectively, compared with 86.7%, 34.8%, 19.3%, and 19.3% in the control group (p<0.01). Overall survival at 1, 2, 3, and 4 years was 100%, 97.6%, 95.0% and 95.0% in the pEL2 group and 100% at 1, 2, 3, and 4 years in the control group (p=0.17). There were no AAA-related deaths in either group. Patients with pEL2 had a significantly increased number of infrarenal aortic branches (p<0.05, respectively). Eighteen patients (40.0%) in the pEL2 group underwent 34 reinterventions for pEL2, with a median follow-up (FU) of 925 days (0-4173). Clinical success was achieved in 9 patients (50.0%). Four patients (8.9%) with pEL2 developed secondary EL1 after a median FU of 1278 days (662-2121).

CONCLUSION

pEL2 are associated with AAA expansion during midterm FU. Further studies are warranted to evaluate the association of AAA expansion due to pEL2 with clinical outcomes to allow recommendations with regard to treatment indications.

Endovascular Aneurysm Repair Compared With Open Repair Does Not Improve Survival in Octogenarians

BACKGROUND

Not every elderly person is frail, and whether it would be beneficial to perform endovascular aneurysm repair (EVAR) solely because a patient is older is unclear. This study aimed to compare the results of EVAR and open surgical repair (OSR) in elderly individuals.Methods and Results:From May 1998 to March 2021, 828 EVAR patients and 886 OSR patients with abdominal aortic aneurysm (AAA) were reviewed. Patients aged ≥80 years were included among them. After propensity score matching by age, sex, and American Society of Anesthesiologists (ASA) classification, the outcomes were compared between patients who underwent EVAR and OSR. The study cohort was composed of 351 EVAR patients and 90 OSR patients. The groups had similar comorbidities, except that EVAR patients were significantly older and had higher ASA classifications. After propensity score matching, 79 pairs of patients were selected. The 30-day mortality (0 vs. 1.2%) and aneurysm-related death (ARD) rates during follow up (2.3% vs. 2.3%, respectively) were similar between the groups. Kaplan-Meier curves revealed that estimated overall survival and freedom from ARD were also similar.

CONCLUSIONS

This study suggests that EVAR cannot improve survival outcomes compared with OSR if applied solely because a patient is aged ≥80 years. Not only age but also other risk factors and quality of life after surgery need to be further studied.

Risk Analysis of Aneurysm Sac Enlargement Caused by Type II Endoleak after Endovascular Aortic Repair

BACKGROUND

Although the preoperative risk factors associated with the occurrence of type II endoleak (ETII) after endovascular aortic repair (EVAR) have gradually become more evident, the preoperative risk factors associated with aneurysm sac enlargement caused by ETII remain unclear. This study aimed to determine the preoperative risk factors associated with aneurysm sac enlargement caused by ETII after EVAR.

METHODS

This retrospective cohort study reviewed 519 EVARs performed for true abdominal aortic aneurysm between January 2006 and December 2018 at our institution. EVARs using commercially available bifurcated devices with no type I or III endoleaks during follow-up and with ≥12 months follow-up were included. A total of 320 patients were enrolled in the study. To identify the preoperative risk factors of sac enlargement after EVAR, Cox regression analysis was used to assess preoperative data.

RESULTS

The median follow-up period was 60.8 months. Overall, 135 of 320 patients (42%) had ETII during follow-up, and 47 of 135 patients (35%) developed aneurysm sac enlargement. Multivariate analysis revealed that chronic kidney disease (CKD) stage ≥4 (hazard ratio [HR], 4.65; 95% confidence interval [CI], 2.13-10.15; P = 0.001), patent inferior mesenteric artery (IMA) (HR, 17.85; 95% CI, 2.46-129.73; P< 0.001), and number of patent lumbar arteries (LAs) (HR, 1.37; 95% CI, 1.13-1.68; P= 0.002) were risk factors of aneurysm sac enlargement caused by ETII.

CONCLUSIONS

CKD stage ≥4, patent IMA, and number of patent LAs were independent risk factors for aneurysm sac enlargement after EVAR. In particular, patent IMA had the highest HR and seemed to have the greatest impact on long-term aneurysm sac enlargement. Hence, taking preoperative measures to address a patent IMA appears to be important in reducing the incidence of sac enlargement.