Identification of Anatomical Risk Factors for Type II Endoleak to Guide Selective Inferior Mesenteric Artery Embolization

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.

Five-year follow-up of randomized clinical trial for pre-emptive inferior mesenteric artery embolization during endovascular aneurysm repair

OBJECTIVE

Type II endoleak (T2EL) is the most common type of endoleak after endovascular aneurysm repair (EVAR) and a common indication for reintervention due to late sac enlargement. Although pre-emptive embolization of the inferior mesenteric artery (IMA) has been proposed to prevent this, no studies have prospectively demonstrated its efficacy. This study aimed to prove the validity of IMA embolization during EVAR in selective cases by analyzing the mid-term outcomes of a randomized clinical trial (RCT).

METHODS

This single-center, parallel-group, non-blinded RCT included participants at high risk of T2EL, characterized by a patent IMA in conjunction with one or more following risk factors: a patent IMA ≥3 mm in diameter, lumbar arteries ≥2 mm in diameter, or an aortoiliac-type aneurysm. The participants were randomly assigned to two groups in a 1:1 ratio: one undergoing EVAR with IMA embolization and the other without. The primary endpoint was T2EL occurrence. The secondary endpoints included aneurysm sac changes and reintervention. In addition to RCT participants, outcomes of patients with low risk of T2EL were also analyzed.

RESULTS

The embolization and non-embolization groups each contained 53 patients. Five-year follow-up after the last patient enrollment revealed that T2ELs occurred in 28.3% and 54.7% of patients in the IMA embolization and non-embolization groups, respectively (P = .006). Both freedom from T2EL-related sac enlargement ≥5 mm and cumulative incidence of sac shrinkage ≥5 mm were significantly higher in the IMA embolization group than in the non-embolization group (95.5% vs 73.6% at 5 years; P = .021; 54.2% vs 33.6% at 5 years; P = .039, respectively). The freedom from T2EL-related sac enlargement ≥10 mm, an alternative indicator for T2EL-related reintervention, showed similar results (100% vs 90.4% at 5 years; P = .019). Outcomes in the low-risk group were preferable than those in the non-embolization group and comparable to those in the IMA embolization group.

CONCLUSIONS

A lower threshold for pre-emptive IMA embolization when implementing EVAR would be more appropriate if limited to patients at high risk of T2ELs.

Midterm outcomes of endovascular repair for abdominal aortic aneurysm using the cuff-first technique to prevent type II endoleaks

OBJECTIVE

The aim of this study was to evaluate the initial and midterm outcomes of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) using the cuff-first technique (CFT) to prevent type II endoleak (T2EL).

METHODS

CFT involves deploying an aortic cuff inside the AAA to cover the ostium of the aortic side branch vessels before deploying the main body. We performed a retrospective review of all patients undergoing EVAR with CFT or side branch embolization (SBE) for AAAs at The Jikei University Hospital between 2016 and 2022. Primary endpoint was the rate of aneurysm sac shrinkage. Secondary endpoints were procedure time, radiation exposure, technical and clinical success rates, occurrence of T2EL, and freedom from reintervention or aneurysm-related death.

RESULTS

Of 406 patients who underwent EVAR for AAAs, CFT was utilized in 56 (CFT group) and SBE in 35 (SBE group); all 91 patients were included in this study. There were no differences in patient demographics between groups, but there were differences in patency rate of the inferior mesenteric artery and absent intraluminal thrombus. The technical success rate per target vessel in the CFT and SBE group was 97.8% and 91.8%, and the clinical success rate was 91.0% and 100%, respectively. The median procedure time was shorter for CFT than for SBE: CFT, 10 (interquartile range [IQR], 6-14) minutes vs SBE, 25 (IQR, 18.5-45) minutes; P < .05), and median radiation exposure was lower for CFT than for SBE (CFT, 1455 (IQR, 840-2634) mGy vs SBE, 2353 (IQR, 1552-3586) mGy; P < .05). During the median follow-up of 25 months (IQR, 12.5-47 months), sac shrinkage occurred at similar rates in both groups (CFT, 37.5% vs SBE, 40.0%; P = .812), and there were no differences in freedom from reintervention (CFT, 96.2% and 91.4% at 12 and 36 months vs SBE, 100% and 89.5% at 12 and 36 months; log-rank P = .761) and freedom from aneurysm-related death (100% at 36 months in both groups; log-rank P = .440). The odds ratio of CFT vs SBE for sac regression was calculated by adjusting for inferior mesenteric artery patency and absent intraluminal thrombus, resulting in no statistical significance (odds ratio, 1.231; 95% confidence interval, 0.486-3.122).

CONCLUSIONS

CFT is feasible with a shorter procedure time and lower radiation exposure than SBE and comparable mid-term outcomes, including sac shrinkage rate, compared with SBE. We believe that CFT, if anatomically suitable, is an alternative to SBE for the prevention of T2EL during EVAR.

Intraoperative evaluation for endoleaks using the SCORPION procedure during endovascular aortic repair

OBJECTIVES

Endoleaks are important complications of endovascular aortic repair. Usually, endoleaks are judged indirectly by aortography or postoperative computed tomography. However, findings from these modalities are difficult to distinguish because of the divergency of endoleaks. Few studies have reported direct visualization of endoleaks. Herein, we introduce a direct procedure for intraoperatively evaluating endoleaks using angioscopy.

METHODS

From April 2023, consecutive patients with an abdominal aortic aneurysm, except emergency cases and those of narrow access, seen at Sunagawa City Medical Center were enrolled in our study. Endoleaks were detected by intraoperative angioscopy using a novel endovascular procedure.

RESULTS

Seven patients underwent endovascular aortic repair of an abdominal aortic aneurysm with intraoperative angioscopy. None of the enrolled patients experienced complications. The procedure revealed types 2, 3a, and 4 endoleaks.

CONCLUSIONS

This is the first study to demonstrate intraoperative visualization of endoleaks using angioscopy. Direct findings observed by this novel procedure might provide information on the velocity and volume of the endoleak, providing comprehensive insights into the intra-sac hemodynamics after the endovascular aortic repair.

Impact of the Patency of Inferior Mesenteric Artery on 7-Year Outcomes After Endovascular Aneurysm Repair

PURPOSE

The impact of preoperative patent inferior mesenteric artery (IMA) on late outcomes following endovascular aneurysm repair (EVAR) remains unclear. This study aimed to investigate the specific influence of IMA patency on 7-year outcomes after EVAR.

MATERIALS AND METHODS

In this retrospective cohort study, 556 EVARs performed for true abdominal aortic aneurysm cases between January 2006 and December 2019 at our institution were reviewed. Endovascular aneurysm repairs performed using a commercially available device with no type I or type III endoleak (EL) during follow-up and with follow-up ≥12 months were included. A total of 336 patients were enrolled in this study. The cohort was divided into the patent IMA group and the occluded IMA group according to preoperative IMA status. The late outcomes, including aneurysm sac enlargement, reintervention, and mortality rates, were compared between both groups using propensity-score-matched data.

RESULTS

After propensity score matching, 86 patients were included in each group. The median follow-up period was 56 months (interquartile range: 32-94 months). The incidence of type II EL at discharge was 50% in the patent IMA group and 19% in the occluded IMA group (p<0.001). The type II EL from IMA and lumbar arteries was significantly higher in the patent IMA group than in the occluded IMA group (p<0.001 and p=0.002). The rate of freedom from aneurysm sac enlargement with type II EL was significantly higher in the occluded IMA group than in the patent IMA group (94% vs 69% at 7 years; p<0.001). The rate of freedom from reintervention was significantly higher in the occluded IMA group than in the patent IMA group (90% vs 74% at 7 years; p=0.007). Abdominal aortic aneurysm-related death and all-cause mortality did not significantly differ between groups (p=0.32 and p=0.34).

CONCLUSIONS

Inferior mesenteric artery patency could affect late reintervention and aneurysm sac enlargement but did not have a significant impact on mortality. Preoperative assessment and embolization of IMA might be an important factor for improvement in late EVAR outcomes.

CLINICAL IMPACT

The preoperative patency of the inferior mesenteric artery was significantly associated with a higher incidence of sac enlargement and reintervention with type II endoleak following endovascular aneurysm repair, even after adjustment for patient background. Preoperative assessment and embolization of inferior mesenteric artery might be an important factor for improvement in late EVAR outcomes.

Efficacy of Sac Coil Embolization in Endovascular Aortic Repair for Sac Shrinkage in Patients at a High Risk of Type II Endoleak from Lumbar Arteries

BACKGROUND

In endovascular aortic repair (EVAR), preemptive embolization of sac branch vessels is effective in preventing postoperative type II endoleak (T2EL). However, this technique has not been widely adopted especially for lumbar arteries (LAs) because of technical difficulties and time constraints. This study aimed to investigate the efficacy of nonselective sac coil embolization, which is a simpler surgical method, in postoperative sac shrinkage for patients at a high risk of T2EL from LAs.

METHODS

We retrospectively assessed 76 patients who underwent elective EVAR for abdominal aortic aneurysm with 4 or more patent LAs or at least 1 patent LA of ≥2 mm at our hospital between January 2014 and December 2022. The patients who underwent sac coil embolization were included in Group Ⅰ (n = 20), and the others were divided into 2 groups: those with an inferior mesenteric artery that was originally occluded or embolized by coils or stent graft bodies (Group Ⅱ, n = 21), and those without that (Group Ⅲ, n = 35). In Group Ⅰ, 0.035-inch coils were inserted into the sac after complete stent graft deployment. The cumulative incidence of sac shrinkage (≥5 mm) was compared between the groups. Further, univariable and multivariable Cox regression analyses were used to determine the predictors of sac shrinkage.

RESULTS

Sac shrinkage (≥5 mm) was observed more frequently in Group Ⅰ (50%) than in Group Ⅱ (19%) and Group Ⅲ (17%) (P = 0.052 and 0.043, respectively). The cumulative incidence of sac shrinkage was significantly higher in Group Ⅰ than in Group Ⅱ (log-rank P = 0.039) and Group Ⅲ (log-rank P = 0.024). Multivariable Cox regression analyses revealed that sac embolization was a significant predictor of sac shrinkage (hazard ratio, 4.23; 95% confidence interval, 1.66-10.8; P = 0.003).

CONCLUSIONS

Nonselective sac coil embolization in EVAR is potentially effective for sac shrinkage in the early postoperative phase in patients at high risk of T2EL from LAs. This simple procedure may improve prognosis after EVAR.

Pre-emptive Aortic Side Branch Embolization during Endovascular Aneurysm Repair Using the Excluder Stent-Graft System: A Prospective Multicenter study

PURPOSE

To evaluate the effectiveness and safety of pre-emptive transcatheter arterial embolization (P-TAE) for aortic side branches (ASBs) to prevent Type 2 endoleaks (EL2) before endovascular aneurysm repair (EVAR) using the Excluder stent-graft system (Excluder).

MATERIALS AND METHODS

In this prospective, multicenter study, 80 patients (mean age, 79.1 years [SD ± 6.7]; 85.0% were men; mean aneurysmal sac diameter, 48.4 mm [SD ± 7.4]) meeting the eligibility criteria were prospectively enrolled from 9 hospitals. Before EVAR, P-TAE was performed to embolize the patent ASBs originating from the abdominal aortic aneurysm. Contrast-enhanced computed tomography (CT) was performed at 1 month and 6 months after EVAR. The primary endpoint was EL2 incidence at 6 months, and the secondary endpoints were aneurysmal sac diameter changes at 6 and 12 months, P-TAE outcomes, adverse events related to P-TAE, reintervention, and aneurysm-related mortality.

RESULTS

All patients successfully underwent P-TAE without serious. Coil embolization was successful in 81.6% of ASBs. EL2 incidence at 6 months was identified in 18 of 70 (25.7%) patients. Aneurysmal sac diameter shrinkage (≥5 mm) was observed in 30.0% of patients at 6 months and in 40.9% at 12 months. Only 1 patient required reintervention for EL2 within 1 year of EVAR; aneurysm-related deaths were not observed.

CONCLUSIONS

P-TAE for ASBs before EVAR using Excluder is a safe and effective strategy. It aids in achieving early aneurysmal sac shrinkage and reduces EL2 reintervention at 1 year after EVAR.

Side branch embolization before endovascular abdominal aortic aneurysm repair to prevent type II endoleak: A prospective multicenter study

PURPOSE

The purpose of the study was to evaluate the efficacy and safety of pre-emptive transcatheter arterial embolization (P-TAE) of aortic side branches to prevent type II endoleak in patients with abdominal aortic aneurysm after endovascular abdominal aneurysm repair (EVAR).

MATERIALS AND METHODS

This multicenter, prospective, single-arm trial enrolled 100 patients with abdominal aortic aneurysm from nine hospitals between 2018 and 2021. There were 85 men and 15 women, with a mean age of 79.6 ± 6.0 (standard deviation) years (range: 65-97 years). P-TAE was attempted for patent aortic side branches, including the inferior mesenteric artery, lumbar arteries, and other branches. The primary endpoint was late type II endoleak incidence at 6 months post-repair. Secondary endpoints included changes in aneurysmal sac diameter at 6- and 12 months, complications, re-intervention, and aneurysm-related mortality. Aneurysm sac changes at 6- and 12 months was compared between the late and no-late type II endoleak groups.

RESULTS

Coil embolization was successful in 80.9% (321/397) of patent aortic side branches, including 86.3% of the inferior mesenteric arteries, 80.3% of lumbar arteries, and 55.6% of other branches without severe adverse events. Late type II endoleak incidence at 6 months was 8.9% (8/90; 95% confidence interval: 3.9-16.8%). Aneurysm sac shrinkage > 5 mm was observed in 41.1% (37/90) and 55.3% (47/85) of the patients at 6- and 12-months post-EVAR, respectively. Patients with late type II endoleak had less aneurysm sac shrinkage than those without type II endoleak at 12 months (-0.2 mm vs. -6.0 mm; P = 0.040). No patients required re-intervention for type II endoleak, and no aneurysm-related mortalities occurred.

CONCLUSION

P-TAE is safe and effective in preventing type II endoleak, leading to early sac shrinkage at 12 months following EVAR.

Outcomes of Late Partial Conversion With Graft Replacement for Sac Enlargement After Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

Outcomes of late open conversion with graft replacement for enlargement after endovascular aortic repair remain unclear. Here, we report the outcomes of graft replacement after endovascular aortic repair.

MATERIALS AND METHODS

Fourteen patients who underwent graft replacement after endovascular aneurysm repair between November 2016 and October 2022 were included. Graft replacement was indicated in cases of rupture and enlargement of the aneurysm sac and when reintervention with endovascular therapy could not be performed.

RESULTS

The mean age at graft replacement was 80 ± 7 years. The follow-up period from endovascular aortic repair to graft replacement was 73 ± 41 months. The endoleaks that caused enlargement of the aneurysm sac were type I in 8 patients and type II in 6 patients. Ruptures were observed in 5 patients. One patient had paraplegia as a postoperative complication, and 2 patients died within 30 days. Morbidity and mortality were observed in cases of rupture, and no morbidity or mortality was observed in any elective surgery cases.

CONCLUSION

Late open conversion with graft replacement after endovascular aortic repair is a feasible elective surgery. However, morbidity and mortality have been observed in cases of rupture.

CLINICAL IMPACT

In elective surgery, postoperative outcomes are good for late open conversion with graft replacement after endovascular aortic repair. On the other hand, morbidity and mortality were observed in case of rupture. Therefore, it is important to perform elective surgical reintervention at the appropriate time.

Safety of preoperative branch embolization in patients undergoing evar

The purpose of this systematic review is to evaluate the safety of pre-endovascular abdominal aortic aneurysm repair (EVAR) embolization of aortic side branches - the inferior mesenteric artery and lumbar arteries. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. A search of MEDLINE and DIMENSION databases identified 9 studies published from 2011 to 2021 that satisfied the inclusion and exclusion criteria. These studies were analyzed to detect the incidence of embolization-related complications. A total of 482 patients underwent preoperative aortic side branch embolization, 30 (6.2%) of whom suffered some kind of minor complication. The only major complication observed was ischemic colitis in 4 (0.82%) patients, two (0.41%) of whom died after bowel resection surgery. Regarding these findings, aortic side branch embolization seems to be a safe procedure, with very low percentages of both minor and major complications.

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.

Preemptive Embolization of the Lumbar Arteries and Inferior Mesenteric Artery to Prevent Abdominal Aortic Aneurysm Enlargement Associated with Type 2 Endoleak Following Endovascular Aneurysm Repair

Purpose

This study aims to evaluate the efficacy of preemptive embolization (PE) of the lumbar arteries (LAs) and inferior mesenteric artery (IMA) (PELI) for preventing abdominal aortic aneurysm (AAA) enlargement associated with type 2 endoleak (T2EL).

Material and Methods

Patients who underwent endovascular aneurysm repair (EVAR) between January 2015 and December 2020 were classified into the control (without PE), IMA (PE of a patent IMA with a diameter ≥2.5 mm), and PELI (PE of patent LAs with a diameter ≥2 mm and IMA) groups. The rate of freedom from AAA enlargement following EVAR (enlargement ≥5 mm from pre-EVAR) was compared using the log-rank test. The prevalence of T2EL at 6 months and 1 year after EVAR was compared using Fisher's exact test.

Results

The cumulative rates of freedom from AAA enlargement at 54 months after EVAR (maximum observational period in the PELI group) were as follows: control group, 77.5%; IMA group, 62.5%; and PELI group, 100%. The mean CT follow-up periods of the control, IMA, and PELI groups were 46.4 ± 22.3, 31.1 ± 20.6, and 22.9 ± 15.5 months, respectively. None of the 31 patients in the PELI group experienced AAA enlargement after EVAR, whereas 2 out of the 16 patients in the IMA group and 20 out of the 98 patients in the control group had AAA enlargement. No significant differences were observed in the rate of freedom from AAA enlargement (PELI group vs. IMA group, P = 0.11; PELI group vs. control group, P = 0.11). The prevalence of T2EL was significantly lower in the PELI group than in the control group at 6 months (13.6% in PELI group vs. 42.1% in control group, P = 0.02) and 1 year (14.3% in PELI group vs. 40.0% in control group, P = 0.04).

Conclusions

PELI was significantly associated with a low prevalence of T2EL and may prevent T2EL-associated AAA enlargement.

Impact of Patent Lumbar Arteries on Aneurysm Sac Enlargement with Type II Endoleak after Endovascular Aneurysm Repair

OBJECTIVE

This study aimed to investigate the impact of the number of patent lumbar arteries (LAs) on sac enlargement after endovascular aneurysm repair (EVAR).

METHODS

This was a retrospective cohort single centre registry study. Between January 2006 and December 2019, 336 EVARs were reviewed using a commercially available device excluding type I or type III endoleaks during a follow up of ≥ 12 months. Patients were divided into four groups based on the pre-operative patency of the inferior mesenteric artery (IMA) and high (≥ 4) or low (≤ 3) number of patent LAs: Group 1, patent IMA and high number of patent LAs; Group 2, patent IMA and low number of patent LAs; Group 3, occluded IMA and a high number of patent LAs; Group 4, occluded IMA and low number of patent LAs.

RESULTS

Groups 1, 2, 3, and 4 included 124, 104, 45, and 63 patients, respectively. The median follow up duration was 65.1 months. Significant differences in the incidence of overall type II endoleak (T2EL) at discharge between Group 1 and Group 2 (59.7% vs. 36.5%, p < .001) and between Group 3 and Group 4 (33.3% vs. 4.8%, p < .001) were observed. In patients with a pre-operatively patent IMA, the rate of freedom from aneurysm sac enlargement was significantly lower in Group 1 than in Group 2 (69.0% vs. 81.7% five years after EVAR, p < .001). In patients with a pre-operatively occluded IMA, the freedom rate from aneurysm sac enlargement was not significantly different between Groups 3 and Group 4 (95.0% vs. 100% five years after EVAR, p = .075).

CONCLUSION

A high number of patent LAs seemed to have a significant role in sac enlargement with T2EL when the IMA was patent pre-operatively, whereas a high number of patent LAs seemed to have limited influence on sac enlargement when the IMA was occluded pre-operatively.

Early- and Mid-Term Results of Abdominal Endovascular Aneurysm Repair Using an Aortic Cuff Prior to the Main Body to Prevent Type II Endoleaks

PURPOSE

Postoperatively persistent type II endoleaks (T2ELs) in abdominal endovascular aneurysm repair (EVAR) are known risk factors for long-term aneurysm enlargement. Therefore, various measures have been proposed to prevent T2ELs. Notably, the Kilt technique, which can be used in patients with dumbbell-shaped morphology, employs an aortic cuff deployed in the distal seal zone before the main body. Although previous studies have successfully applied this technique for preventing T2ELs, the mid- and long-term outcomes remain unclear. This study aimed to report the early- to mid-term outcomes in cases where an aortic cuff technique was used to prevent T2ELs.

MATERIALS AND METHODS

This retrospective single-center study analyzed 9 patients (mean age, 79 years; range, 69-88 years; 8 men) with abdominal aortic aneurysms. All patients underwent EVAR using an aortic cuff to prevent T2ELs. The primary end points were technical success (successful deployment) and clinical success (no T2ELs). Secondary end points included morbidity, reintervention, and aortic remodeling during follow-up.

RESULTS

The technical success rate was 100%. There were no intraprocedural or postoperative complications. No deaths or reinterventions occurred. Postoperative computed tomography showed no endoleaks in 6 patients, while T2ELs from the lumbar artery outside the aortic cuff deployment range were noted in 3 patients. However, no T2ELs were observed in the artery in the aortic cuff deployment range in any patient. The average number of successfully occluded arteries was 4.2 (range, 2-8). All patients had follow-up >6 (mean, 18.6; range, 6-36) months. Aneurysm sac shrinkage occurred in 5 patients during the follow-up period, whereas aneurysm size was stable in 3 patients. In contrast, only 1 patient showed transient dilation of the aneurysm sac enlargement; however, this dilation remained unchanged even after 1.5 years.

CONCLUSION

The aortic cuff technique is a favorable endovascular method for preventing T2ELs in EVAR. The present study showed that a single aortic cuff could easily and reliably occlude arteries branched from the aneurysm sac.

Detection of Endoleaks Following Thoracic and Abdominal Aortic Endovascular Aortic Repair-: A Comparison of Standard and Dynamic 4D-Computed Tomography Angiography

PURPOSE

Endoleaks are a common complication after endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR). The detection and correct classification of endoleaks is essential for the further treatment of affected patients. However, standard computed tomography angiography (CTA) provides no hemodynamic information on endoleaks, which can result in misclassification in complex cases. The aim of this study was to compare standard CTA (sCTA) with dynamic, dual-energy CTA (dCTA) for detection and classification of endoleaks following EVAR or TEVAR.

MATERIALS AND METHODS

This retrospective evaluation compared 69 sCTA diagnostic examinations performed on 50 different patients with 89 dCTA diagnostic examinations performed on 69 different patients.

RESULTS

In total, 15.9% of sCTA examinations and 49.4% of dCTA examinations led to the detection of endoleaks. With sCTA, 20.0% of patients were diagnosed with endoleaks, while with dCTA, 37.7% of patients were diagnosed with endoleaks. With sCTA, mainly Type 1 endoleaks were detected, whereas, with dCTA, the types of detected endoleaks were more evenly distributed. In comparison with the literature, the frequencies of endoleak types detected with dCTA better reflect the natural distribution than the frequencies detected with standard CTA.

CONCLUSION

Based on the retrospective comparative evaluation, dCTA could pose a valuable supplementary diagnostic tool resulting in a more accurate and realistic detection and classification of suspected endoleaks.

Inferior mesenteric artery revascularization can supplement salvage of mesenteric ischemia

The inferior mesenteric artery (IMA) has often been overlooked in favor of the celiac or superior mesenteric artery in arterial mesenteric ischemia, owing to the typically robust visceral collateral networks. In the present report, we have described a case series of patients in whom "salvage" revascularization of the IMA was performed after attempted celiac or superior mesenteric artery revascularization had been unsuccessful. The restored IMA inflow had resolved the symptoms for three patients. However, sole IMA revascularization was insufficient to reverse the course for two other patients with severe acute-on-chronic mesenteric ischemia. The IMA should be considered for salvage revascularization in the appropriate clinical scenario.

Role of Aggressive Aneurysm Sac Embolization Before Endovascular Abdominal Aneurysm Repair in Preventing Type II Endoleak and Sac Expansion

Background

This study aimed to evaluate the effect of aggressive embolization of side branches arising from the aneurysmal sac before endovascular aneurysm repair.

Methods

This retrospective study included 95 patients who underwent endovascular infrarenal abdominal aortic aneurysm repair at Tottori University Hospital between October 2016 and January 2021. Of these, 54 underwent standard endovascular aneurysm repair (conventional group), and 41 underwent coiling of the inferior mesenteric and lumbar arteries before undergoing endovascular aneurysm repair (embolization group). The occurrence of type II endoleak, change in aneurysmal sac diameter, and reintervention rate due to type II endoleak during follow-up were evaluated.

Results

Compared to the conventional group, the embolization group had a significantly lower incidence of type II endoleak, more frequent aneurysmal sac shrinkage, and lower aneurysmal sac growth related to type II endoleak.

Conclusion

Our results demonstrated the effectiveness of aggressive aneurysmal sac embolization before endovascular aneurysm repair to prevent type II endoleak and the consequent long-term aneurysmal sac enlargement.

Feasibility of aortic aneurysm sac embolization using a novel shape memory polymer embolic device

BACKGROUND

We investigated the feasibility of aneurysm sac embolization using a novel self-expanding porous shape memory polymer (SMP) device during endovascular aortic abdominal or thoracic aneurysm repair (EVAR).

METHODS

Retrospective analysis of consecutive patients treated at 2 centers in Germany. Patients were treated from January 2019 to July 2021 with follow-up at 7 days and 3, 6, and 12 months. Aneurysm sacs were implanted with SMP devices immediately following endograft placement during the same procedure. Primary endpoint was technically successful SMP-device deployment into the aneurysm sac outside the endograft. Secondary endpoints were changes in aneurysm volume and associated complications (e.g., endoleaks).

RESULTS

We included 18 patients (16 males), aged 72 ± 9 years, achieving 100% technical success. Mean preprocedure aortic aneurysm sac volume was 195 ± 117 mL with a perfused aneurysm volume of 97 ± 60 mL. A mean of 24 ± 12 SMP devices per patient were used (range 5-45, corresponding to 6.25-56.25 mL expanded embolic material volume). All evaluable patients exhibited sac regression except 2 patients yet to reach 3-month follow-up. At mean 11 ± 7 months (range 3-24), change in aneurysm volume from baseline was -30 ± 21 mL (p < 0.001). In 8 patients, aneurysm regression was observed despite type 2 endoleaks in 6 and type 1A endoleaks in 2, none of them requiring further intervention to date. No morbidity or mortality related to this treatment occurred.

CONCLUSIONS

SMP devices for aortic aneurysm sac embolization during endovascular repair appear feasible and safe in this small case series. Prospective studies are needed.

KEY POINTS

• Shape memory polymer is a novel, self-expanding, porous, and radiolucent embolic device material. • Aortic aneurysm sacs were treated with polymer devices immediately following endograft placement. • Aortic aneurysm sac regression was observed in all patients with over 3-month follow-up. • Aortic aneurysm sac regression was observed even in the presence of endoleaks.

Routine Inferior Mesenteric Artery Embolisation is Unnecessary Before Endovascular Aneurysm Repair

OBJECTIVE

A type II endoleak is the most common complication during surveillance after endovascular aneurysm repair (EVAR), and a patent inferior mesenteric artery (IMA) is a known risk factor for an endoleak. The effect of routine IMA embolisation prior to EVAR on overall outcome is unknown. The aim of the study was to compare two strategies: routine attempted IMA embolisation prior to EVAR (strategy in centre A) and leaving the IMA untouched (strategy in centre B).

METHODS

Patients were treated with EVAR in two centres during the period 2005 - 2015, and the data were reviewed retrospectively. The primary endpoints were re-intervention rate due to type II endoleaks and the late IMA embolisation rate. Secondary endpoints included EVAR related re-intervention, sac enlargement, aneurysm rupture, and open conversion rates.

RESULTS

Strategy A was used to treat 395 patients. The IMA was patent in 268 (67.8%) patients, and embolisation was performed in 164 (41.5%). The corresponding figures for strategy B were 337 patients with 279 (82.8%) patent IMAs, two (0.6%) of which were embolised. The mean duration of follow up was 70 months for strategy A and 68.2 months for strategy B. The re-intervention rates due to a type II endoleak were 12.9% and 10.4%, respectively (p = .29), with no significant difference in the rate of re-interventions to occlude a patent IMA (2.0% and 4.7%, respectively; p = .039). The EVAR related re-intervention rate was similar, regardless of strategy (24.1% and 24.6%, respectively; p = .93). Significant sac enlargement was seen in 20.3% of cases treated with strategy A and in 19.6% treated with strategy B (p = .82). The rupture and conversion rates were 2.5% and 2.1% (p = .69) and 1.0% and 1.5% (p = .40), respectively.

CONCLUSION

The strategy of routinely embolising the IMA does not seem to yield any significant clinical benefit and should therefore be abandoned.

Preoperative predictive factors for type II endoleak: Trying to define high-risk patients

OBJECTIVE

Type 2 endoleaks (T2E) continue to be the "Achilles Heel" of endovascular aneurysm repair (EVAR). The aim of this study is to analyze preoperative factors of patients who underwent EVAR to define risk factors for T2E.

METHODS

From January 2015 to June 2020, 140 of 191 patients who underwent EVAR in our institution meet inclusion criteria for this study. Postoperative image control were performed using duplex ultrasound or CT scan. All T2E detected during follow-up were confirmed by angio CT. Preoperative anatomic and clinical variables were analyzed for T2E using t-test, Mann-Whitney U test and Fisher exact test. ROC curves and the corresponding area under the curve (AUC) were used to describe the predictive accuracy for endoleak.

RESULTS

T2E was detected in 16 patients (11.43%)0.12 of them (75%) were persistent and 10 (62.5%) provoked sac enlargement. Predictive factors for T2E were a greater IMA diameter (2.5 ± 0.5 vs. 3.3 ± 0.5, p < 0.001) and an increasing number of LA (4.8 ± 1.6 vs. 6.7 ± 1.4, p < 0.001). ROC curve analysis stablished thresholds of 3.5 mm for IMA diameter (sensitivity 77%, specificity 86%) and 5.5 for patent LA (sensitivity 88%, specificity 59%) as risk factor to develop T2E.

CONCLUSIONS

Preoperative aortic side branches embolization to avoid T2E is not still standarised. We tried to define a group of high-risk patients for T2E. According to our findings, patients with a preoperative IMA> 3 mm and more than 5 patent LA should be considered for pre-EVAR embolization.

Five-year outcomes of the Bi- versus Trimodular EndurantTM stent-graft in 100 patients with infrarenal abdominal aortic repair

BACKGROUND

Recent studies on the Endurant™ endografts mainly compared outcomes of the bimodular stent-graft to other manufacturer's endografts or reported results for cases outside manufacturer's instructions for use (IFU), while data on the experience of standard endovascular aortic repair (EVAR) of infrarenal abdominal aortic aneurysms (AAA) inside manufacturer's IFU comparing the bi- with the trimodular device is limited.

METHODS

Inclusion criteria were: 1) infrarenal aneurysms (>50 mm diameter) treated by Endurant^TM II (END II) or Endurant^TM IIs (END IIs) stent-graft inside manufacturer's IFU; 2) available CTA with 1 mm reconstruction of the entire aorta prior to intervention. Endpoints comparing the devices included technical success, 30-day mortality, rate of complications (bleeding with conversion to open repair, stent-graft stenosis/occlusion, acute distal embolism, infection or postprocedural necessity of dialysis), endoleaks and reinterventions (5-year follow-up). Aneurysm sac diameters were compared between baseline preinterventional CTA and last post-interventional CTA.

RESULTS

One hundred patients (90% male, mean age 74 years) treated with END II (N.=66) or END IIs (N.=34) were included. Technical success was 99%. One procedure-related active bleeding occurred ending up in surgical conversion (END II N.=1). 30d mortality was 0%. No initial type I/III endoleaks were present. Re-interventions were required in 19/100 (19%) of patients (END II N.=10; END IIs N.=9, P=0.17). The outcome of EVAR including technical success, 30d mortality, rate of complications, endoleaks and re-interventions showed no significant differences comparing END II/IIs.

CONCLUSIONS

Five-year outcomes of EVAR show consistently safe and effective results for either END II or IIs device.

Laparoscopic Management of Concomitant Sigmoid Colon Cancer and Type 2 Endoleak Following Endovascular Aneurysm Repair

The co-occurrence of abdominal aortic aneurysm (AAA) and colorectal malignancy creates a significant surgical dilemma over which entity should be addressed first. A 73-year-old male was referred to our hospital due to a painful pulsatile abdominal mass. Computed tomographic angiography revealed an infrarenal aortic aneurysm measuring 5.8 cm in diameter and incidentally, a synchronous mass lesion in the sigmoid colon. The patient underwent an emergency EVAR using a Gore Excluder endograft. Postoperative CT staging for colon cancer revealed a type 2 endoleak on the grounds of a patent wide inferior mesenteric artery. The patient underwent a standard laparoscopic left colectomy with high ligation of the inferior mesenteric artery in order to simultaneously address the ongoing type 2 endoleak. Follow-up examinations with computed tomographic angiography were performed confirming the resolution of the endoleak. Synchronous laparoscopic sigmoidectomy and high ligation of inferior mesenteric artery for type 2 endoleak treatment appears to be applicable with hopeful results.

Significance of preoperative thrombus burden in the prediction of persistent Type II endoleak and re-intervention following infra-renal EVAR

BACKGROUND

Persistent Type II endoleak has necessitated prolonged surveillance and is a reason for re-intervention following infra-renal endovascular aneurysm repair (EVAR). The aim of this study was to assess the association of thrombus burden (TB) within the aneurysmal sac in the prediction of persistent Type II endoleaks.

METHODS

Consecutive patients undergoing infra-renal EVAR from October 2009 to October 2017 in a single vascular network were included. TB was assessed on preoperative CT-angiogram and was defined as a percentage of thrombus across the maximal sac diameter in comparison to the luminal diameter measured orthogonally at the same level. Patients were categorised into 3 groups; Low TB (<25%), Medium TB (25%-50%) and High TB (>50%). All patients underwent postoperative EVAR surveillance comprising of computed tomographic angiography or duplex ultrasound. Type II endoleak observed for more than one year was defined as persistent Type II endoleak. Odds ratio and Student's T-test were used to determine significance.

RESULTS

Some 275 EVARs were performed in the study period. 45 procedures were excluded due to either iliac-only intervention (n=9), no pre-operative information (n=7), abandoned (n=1) or less than 1 year's follow-up data (n=28). For the 230 procedures included, the median follow-up was 43 (12-102) months. There were no significant differences between the groups for age, gender, co-morbidities nor preoperative sac diameter. There was high inter-observer reliability with a kappa value of 0.89 (0.84-0.94) with a total discordance of 7% across the cohorts. Persistent Type II endoleak occurred significantly more frequently with reduced TB: 41% of the low TB cohort compared with 4% of the high TB cohort [OR 15.36 (3.5-67.3) p=0.0003]. Re-intervention was also significantly more likely to occur in the presence of a persistent Type II endoleak compared to its absence; n=12/13 (92%) patients who underwent re-intervention had a persistent Type II endoleak [OR 43.4 (5.5-242) p=0.0003]. Sac size reduction was significantly greater in medium TB and high TB cohorts when compared to low TB; -25% and -27% vs. -15% (p=0.0046 and p<0.0001). Decreased TB was associated with a significant increase in Inferior Mesenteric Artery (IMA) patency; the mean TB, where the IMA was patent, being 29% compared to 40% where the IMA was occluded p<0.0001. When considered together, patients with a low TB and a patent IMA were even more likely to have a persistent Type II endoleak when compared to those with a high TB and an occluded IMA; [OR 34.1 (1.99-583) p=0.015].

CONCLUSION

Low thrombus burden is associated with increased rates of persistent Type II endoleak, especially in the presence of a patent IMA. High thrombus burden is associated with increased sac regression and low re-intervention rates. Thrombus burden can be assessed reliably and could be used for risk stratification in the planning of infra-renal EVAR. Pre-emptive embolization of IMA or lumbar vessels in those with low thrombus burden may be beneficial. Thrombus burden could be a useful tool for designing post-EVAR surveillance regimen.

Midterm Outcomes of Endovascular Abdominal Aortic Aneurysm Repair with Prevention of type 2 Endoleak by Intraoperative Aortic Side Branch Coil Embolization

OBJECTIVE

The midterm results of endovascular abdominal aortic aneurysm repair (EVAR) with aortic side branch coil embolization during EVAR was evaluated.

METHODS

Our center began coil embolization for all patent inferior mesenteric artery (IMA) and lumbar artery (LA) with an inner diameter more than 2.0 mm during EVAR since June 2015. When four or more LA were patent, coil embolization for LA with inner diameter 2.0 mm or less was done. EVAR without aortic side branches coil embolization was performed for 59 patients prior to June 2015 (control group) and 79 patients underwent EVAR with coil embolization during EVAR (coil group). The success rate of coil embolization for IMA and LA was evaluated in coil group. The frequency of type 2 endoleak (T2EL), freedom from aneurysm sac expansion (5 mm or more) rate and the rate of the aneurysm sac shrinkage (10 mm or more) were compared between the coil and control groups. Additionally, multiple logistic regression analysis for all patients was conducted to analyze whether IMA patency and the number of patent lumbar artery at the end of EVAR were the risk factors of the aneurysm sac expansion of 5 mm or more.

RESULTS

The success rate of IMA coil embolization was 96.4% and that of LA was 74.5%. Compared to the control group, the frequency of T2EL was significantly lower in coil group at 7 days (1.3% vs. 60.4%, P <0.0001) and at 6 months (2.1% vs 38.2%, P <0.0001) after EVAR. The freedom from aneurysm sac expansion rate was significantly better in the coil group at 5 years (100% in coil group and 65.2% in control group, P = 0.002). The rate of aneurysm sac shrinkage was significantly better in coil group (15.5% vs. 2.0% at 1 year, 42.8% vs. 6.3% at 2 years and 53.4% vs. 17.8% at 3 years, p = 0.0007). The risk of aneurysm sac expansion of 5 mm or more was estimated to be 11 times greater when the IMA was patent, and 4.9 times greater when 3 or more LAs were patent at the end of EVAR.

CONCLUSION

When IMA was occluded and the number of patent LA became 2 or less by aortic side branch coil embolization during EVAR, favorable mid-term results were safely obtained and good long-term result could be expected with EVAR.

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.

Effectiveness of collateral arteries embolization before endovascular aneurysm repair to prevent type II endoleaks: A systematic review and meta-analysis

OBJECTIVES

This study aimed to evaluate the effect of preventive collateral arteries embolization before endovascular aneurysm repair (EVAR) to reduce type II endoleaks (T2EL), aneurysm enlargement, and re-interventions.

METHODS

A comprehensive search of PubMed, MEDLINE, Web of Science, and Embase was conducted to identify articles in English, related to preventive collateral arteries embolization before EVAR, published until October 2020.

RESULTS

A total of 12 relevant studies, including 11 retrospective studies and one randomized controlled trial, were identified and fulfilled the specified inclusion criteria. A total of 1706 patients in 11 studies were involved in the meta-analysis. The overall incidence of T2EL was 17.3% in the embolization group vs. 34.5% in the control group (OR 0.36, p < 0.01). The incidence of persistent T2EL was 15.3% vs. 30.0% (OR 0.37, p < 0.01). Five studies reported the incidence of sac enlargement, with the rate 10.2% vs. 24.9% (OR 0.25, p < 0.01). Nine studies reported T2EL related re-interventions, and it was 1.3% in the embolization group and 10.4% in control (OR 0.14, p < 0.01). The technical success of collateral arteries embolization was 92.1% (455/494) in the 12 studies. 1.2% (10/829) patients suffered a mild complication of collateral arteries embolization, and 2/829 patients died because of the embolization.

CONCLUSION

Collateral arteries embolization is a promising measure to prevent the occurrence of T2EL, sac enlargement, and re-intervention. High-quality studies need to be conducted to provide stronger evidence-based medical suggestions about the embolize operation.

Predictive Factor of the Possibility for Aortic Side Branches Coil Embolization during Endovascular Abdominal Aortic Aneurysm Repair

Objective: Coil embolization of aortic side branches has been additionally performed to prevent type II endoleak during EVAR in our institute. In this study, we evaluated the predictive factors of the possibility for coil embolization of the inferior mesenteric artery (IMA) and lumbar artery (LA) during EVAR.

Methods: Seventy-four EVAR patients during June 2015 and April 2019 were included in the study. The coil embolization procedural time for one vessel is limited to 10 min. Aortic side branches were selected with 4 Fr Shepherd hook type catheter (Medikit, Tokyo, Japan) and were embolized with Interlock (Boston Scientific, MA, USA) via microcatheter. As predictive factors, internal diameter of aortic side branches and the aortic diameter perpendicular to the origin of LA (aortic diameter) were evaluated.

Results: Coil embolization was tried for 52 patent IMAs and all IMAs except two IMAs with ostial stenosis were successfully coil embolized (96.2%). Totally 190 LAs were patent and coil embolization was tried for 144 LAs. Among 144 LAs, 106 LAs (73.6%) were successfully coil embolized and the diameter was significantly longer (2.30±0.51 mm vs. 2.04±0.41 mm, p=0.007) and aortic dimeter was significantly shorter (30.0±8.1 mm vs. 40.5±11.6 mm, p<0.001) in successfully embolized LAs. Cut off value of successful LA coil embolization was 2.06 mm for internal diameter and 36.1 mm for aortic diameter by receiver operating characteristic curve analysis. Successful coil embolization rate for LAs with internal diameter longer than 2.0 mm and aortic diameter less than 36.2 mm was 90% (72 among 80 LAs).

Conclusion: Coil embolization during EVAR for IMA was highly successful, if there was no calcified ostial stenosis. LA embolization was feasible especially for LAs with internal diameter ≥2.0 mm and aortic diameter ≤36.1 mm. This information would be useful to select the target vessel for aortic side branches coil embolization during EVAR. (This is a translation of Jpn J Vasc Surg 2019; 28: 389–396.)

Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm: A Comprehensive Review

Abdominal aortic aneurysm (AAA) can be defined as an abnormal, progressive dilatation of the abdominal aorta, carrying a substantial risk for fatal aneurysmal rupture. Endovascular aneurysmal repair (EVAR) for AAA is a minimally invasive endovascular procedure that involves the placement of a bifurcated or tubular stent-graft over the AAA to exclude the aneurysm from arterial circulation. In contrast to open surgical repair, EVAR only requires a stab incision, shorter procedure time, and early recovery. Although EVAR seems to be an attractive solution with many advantages for AAA repair, there are detailed requirements and many important aspects should be understood before the procedure. In this comprehensive review, fundamental information regarding AAA and EVAR is presented.

Multicentre randomised controlled trial to evaluate the efficacy of pre-emptive inferior mesenteric artery embolisation during endovascular aortic aneurysm repair on aneurysm sac change: protocol of Clarify IMA study

INTRODUCTION

Type II endoleak (EL) is frequently seen after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) and is often considered responsible for aneurysm sac enlargement if it persists. In order to reduce type II EL and consequent sac enlargement, pre-emptive embolisation of the inferior mesenteric artery (IMA), which is a main source for persistent type II EL, has been introduced in many vascular centres. At present, there is a lack of robust evidence to support the efficacy of pre-emptive embolisation of IMA on reduction of persistent type II EL with subsequent sac shrinkage.

METHOD AND ANALYSIS

This multicentre, randomised controlled trial will recruit 200 patients who have fusiform AAA ≥50 mm/rapidly enlarging fusiform AAA, with patent IMA, and randomly allocate them either to a pre-emptive IMA embolisation group or non-embolisation control group in a ratio of 1:1. The primary endpoint is the difference of aneurysm sac volume change assessed by CT scans between the pre-emptive IMA embolisation group and the control group at 12 months after EVAR. The secondary endpoints are defined as change of aneurysm sac volume in both groups at 6 and 24 months, freedom from sac enlargement at 12 and 24 months after EVAR, prevalence of type II EL at 1, 6, 12 and 24 months evaluated by contrast-enhanced CT, reintervention rate, aneurysm related mortality, overall survival, perioperative morbidity, volume of contrast media used during EVAR and dosage of radiation.

ETHICS AND DISSEMINATION

The protocol has been reviewed and approved by the ethics committee of Nara Medical University (No. 2113). The findings of this study will be communicated to healthcare professionals, participants and the public through peer-reviewed publications, scientific conferences and the University Hospital Medical Information Network Clinical Trials Registry home page.

TRIAL REGISTRATION NUMBER

UMIN000035502.

Recent Update of Endovascular Type 2 Endoleak Management

EVAR has been used clinically for almost three decades, and it has been widely applied in clinical practice and has been applied to difficult cases as devices and techniques have evolved. Although the major advantage of EVAR is its lower perioperative mortality, compared with open surgery, late-onset complications such as endoleaks have become major issues, requiring lifelong follow-up after EVAR. The clinical guidelines have been updated, and many systematic reviews/meta-analyses and multi-center registries have been published; surgeons must keep up-to-date regarding these changes. In this review, the author reviews evidence on the recent update of the type 2 endoleak management.

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

BACKGROUND

Several studies have analyzed risk factors that may influence the incidence of type II endoleak with sac expansion after endovascular aneurysm repair (EVAR). However, the impact of intraluminal thrombus volume on the incidence of sac expansion with type II endoleak requires further analysis. This study examined the correlation between preoperative intraluminal thrombus and the incidence of type II endoleak and late sac expansion by measuring the thrombus volume.

METHODS

Between June 2007 and March 2014, 423 patients underwent EVAR at our institution. Two hundred and eighty patients with preoperative and postoperative computed tomography angiography (CTA) were included in this study. Data were collected prospectively and supplemented with a retrospective review of the medical records and radiologic images, and demographic and clinical characteristic profiles were collected. Logistic regression and Cox regression analyses were used to assess each variable's association with the incidences of persistent or new endoleak and sac expansion.

RESULTS

Of the 280 patients, 46.7% (131 patients) had persistent type II endoleak, and 19.6% (55 patients) had persistent type II endoleak with significant sac expansion (≥5 mm). The mean follow-up duration was 60 months (interquartile range, 24-72 months). Cox regression analysis showed that older age (P = 0.001), intraluminal thrombus volume ratio (thrombus volume [T vol]/aortic aneurysm volume [A vol]) (P = 0.042) and IMA diameter (P = 0.004) were significant predictors of the incidence of sac expansion with persistent or new type II endoleak. The receiver operating characteristic curve analysis revealed a cutoff of 51% T vol/A vol (area under the curve [AUC]: 0.59) and 2.9 mm (area under the curve [AUC]: 0.60). The rate of freedom from sac expansion (≥5 mm) during followup was significantly higher in patients with ≥51% T vol/A vol than in those with a lower T vol/A vol (P = 0.010).

CONCLUSIONS

Preoperative sac thrombus volume, IMA diameter, and older age predict the incidence of aneurysm expansion with type II endoleak after EVAR.

Fate of Pure Type II Endoleaks Following Endovascular Aneurysm Repair

Purpose

Type II endoleaks (T2ELs) are the most common type of endoleaks observed after endovascular aneurysm repair (EVAR). However, whether T2ELs should be treated remains debatable. In the present study, we aimed to describe the natural course of T2ELs and suggest the direction of their management.

Materials and Methods

We reviewed the data of 383 patients who underwent EVAR between 2007 and 2016. Data, including demographic and anatomical details, were collected, and patients with T2ELs were compared to those without them. Patients with T2ELs were categorized into subgroups according to changes in sac size and treatment requirement.

Results

We found patent lumbar artery count and lesser thickness of mural thrombi to be significant risk factors for T2ELs. Among the 383 patients, 85 (22.2%) patients were diagnosed with pure T2ELs. Among these 85 patients, the sac size increased in 29 (34.1%) patients, showed no significant change in 39 (45.9%) patients, and decreased in 17 (20.0%) patients. Fifteen (17.6%) patients, among 85 with initial pure T2ELs, showed spontaneous resolution. Five (5.9%) patients among 29, in whom the sac size increased, developed combined-type endoleaks. No sac ruptures were noted among the patients with T2ELs.

Conclusion

T2ELs with sac expansion potentially contribute to other types of endoleaks. Therefore, periodic screening is important for these patients, particularly for those showing an increasing sac size. In addition, intervention should be considered when other types of endoleaks occur.

Nonsteroidal anti-inflammatory drug use is a risk factor for early Type II endoleak after endovascular abdominal aortic repair

Objectives

Type II endoleak is a problem after endovascular abdominal aneurysm repair. Preoperative risk factors for Type II endoleak include anatomical factors in the lumbar artery and inferior mesenteric artery; however, preventable postoperative risk factors are unknown. Postimplantation syndrome is associated with lower incidence of Type II endoleak. Therefore, we focused on inflammation, and our aim was to investigate nonsteroidal anti-inflammatory drugs as a postoperative risk factor for Type II endoleak.

Methods

This was a retrospective study of patients with aortic aneurysm who underwent endovascular aneurism repair at the Department of Cardiovascular Surgery, Beppu Medical Center, Oita, Japan, from January 2011 to August 2018. Clinical characteristics were retrieved from patients’ medical records and included age, sex, body mass index, smoking history, comorbidities, treatment devices, medications, and perioperative information, including postimplantation syndrome. Postimplantation syndrome was defined as body temperature >38.5°C with 12,000/dL white blood cells or >10.0 mg/dL C-reactive protein. The primary outcome was the presence or absence of Type II endoleak assessed on the first postoperative enhanced computed tomography scan. Risk factors for Type II endoleak were assessed. Results and conclusions: Of the eligible 84 patients, 20 (24%) had Type II endoleak identified in the first enhanced computed tomographic scans after endovascular aneurism repair. Nonsteroidal anti-inflammatory drug use (odds ratio (OR): 21.2; 95% confidence interval (95% CI): 1.5–308.4; P = 0.026), cerebrovascular disease (OR: 7.27; 95% CI: 1.06–49.99; P = 0.044), and body mass index <22 kg/m2 (OR: 17.3; 95% CI: 2.1–141.8; P = 0.008) were independent risk factors for Type II endoleak after endovascular aneurism repair. Comparing the rate of Type II endoleak among patients who did not receive nonsteroidal anti-inflammatory drugs within 24 h after endovascular aneurism repair, patients who first used nonsteroidal anti-inflammatory drugs 12–24 h after endovascular aneurism repair, and those who received nonsteroidal anti-inflammatory drugs within 12 h after endovascular aneurism repair, we found a significant difference among the groups (4%, 18%, 45%, respectively; P = 0.001). Nonsteroidal anti-inflammatory drug use within 24 h after endovascular aneurism repair is a risk factor for Type II endoleak. We should know nonsteroidal anti-inflammatory drugs within 24 h after endovascular aneurism repair can be a risk of Type II endoleak.

Recent Advances and Mid-to-Long Term Results of Endovascular Aneurysm Repair for Abdominal Aortic Aneurysms

Endovascular aneurysm repair (EVAR) has become the standard therapy alongside open surgery repair (OSR) for abdominal aortic aneurysm (AAA) and it is rapidly becoming prevalent. There has been substantial technical progress with respect to EVAR since its introduction. Technical contrivance can be used to manage even inappropriate EVAR cases, including those involving a hostile neck, deficient access route, or aneurysm rupture. However, there are some controversies over reinterventions in relation to long-term outcomes. Although a long-term result has not yet been analyzed in Japan a randomized controlled trial (RCT) held in the West reported that OSR is superior to EVAR for avoiding reinterventions and aneurysm-related death. The RCT involved the use of older devices and proceeded in a different way from the present study; therefore, different results may be obtained for Japanese EVAR outcomes. However, this Western RCT result should be considered as an important warning. Type II endoleak also must be managed in order to improve long term outcomes of EVAR. Efforts to improve both technical methodology and long-term outcomes are necessary to ensure EVAR as a minimally invasive therapy for patients with AAA. (This is a translation of Jpn J Vasc Surg 2018; 27: 405-411.).

Type II Endoleak After Endovascular Aortic Aneurysm Repair Using the Endurant Stent Graft System for Abdominal Aortic Aneurysm with Occluded Inferior Mesenteric Artery

PURPOSE

To evaluate the incidence of type II endoleak (EL-II) and aneurysm enlargement after endovascular aneurysm repair (EVAR) using the Endurant stent graft in patients with abdominal aortic aneurysm (AAA) with occluded inferior mesenteric artery (IMA).

MATERIALS AND METHODS

Between 2012 and 2017, 103 patients who underwent EVAR using the Endurant stent graft for AAA with occluded IMA (50 patients with prophylactic embolized IMA and 53 with spontaneous occluded IMA) were retrospectively reviewed. The incidence of EL-II and aneurysm enlargement was evaluated. Predictive factors for persistent EL-II were evaluated based on patient characteristics, preprocedural anatomical characteristics, intraprocedural details, and postprocedural complications.

RESULTS

Incidence rates of early EL-II and persistent EL-II were 6.8% (7/103 patients) and 4.9% (5/103 patients), respectively. Aneurysm enlargement was found in 10 patients (9.7%), including all 5 patients with persistent EL-II, 3 with de novo EL-II, and 2 with no EL-II. The rates of freedom from aneurysm enlargement at 1, 2, and 3 years were 98.7%, 97.0%, and 93.1% for the group without persistent EL-II, and 80.0%, 60.0%, and 20.0% for the group with persistent EL-II (p < 0.001), respectively. The maximum aneurysm diameter (odds ratio (OR), 1.16; 95% confidence interval (CI), 1.01-1.34; p = 0.0362) and the number of patent lumbar arteries (OR, 2.72; 95% CI, 1.07-6.90; p = 0.0357) were predictive of persistent EL-II.

CONCLUSIONS

The incidence of EL-II after EVAR using the Endurant stent graft for AAA with occluded IMA was low, but most early EL-II persisted and resulted in aneurysm enlargement. Level of Evidence Level 4, Case Series.

Effectiveness of Embolization of Inferior Mesenteric Artery to Prevent Type II Endoleak Following Endovascular Aneurysm Repair: A Review of the Literature

Type II endoleak is a common complication that develops after endovascular aneurysm repair. Patients with type II endoleak, which has persisted for 6 months, have a significantly higher rate of aneurysmal sac enlargement, reintervention, and rupture. To date, several studies have examined the effectiveness of preoperative embolization of branch vessels for the prevention of type II endoleak. Particularly, the embolization of the large inferior mesenteric artery (IMA) seems to be a precise, safe, and effective method. IMA is a significant risk factor for type II endoleak. However, there is currently no strong evidence to prove which patients would benefit from preventive IMA embolization. In addition, considering the incidence of type II endoleak and the adverse event rate, routine embolization seems to be unreliable and time-consuming. Moreover, previous reports of preoperative IMA embolization were retrospective. Thus, prospective and randomized studies are necessary so that the usefulness of IMA embolization can be proved and the potential benefits can be assessed. To establish preventive IMA embolization as one of the effective therapeutic strategies to prevent type II endoleak and to maximize its therapeutic effect, we should provide a wide range of therapeutic strategies to suit the state of the patient.