Characterization and management of type II and complex endoleaks after fenestrated/branched endovascular aneurysm repair

Effect of Aortic Thrombus on Outcomes Following Repair of Juxtarenal Aneurysms Using Physician Modified Endografts

OBJECTIVE

Studies have suggested that aortic thrombus may be associated with adverse outcomes following endovascular repair of aortic aneurysms, while other reports have suggested higher rates of sac regression and a reduced risk of endoleak. However, the effect of thrombus burden on outcomes following physician modified endografts (PMEGs) remains unknown. This study aimed to assess the volume and morphology of thrombus burden and the effect on outcomes following PMEG for juxtarenal abdominal aortic aneurysm.

METHODS

This was a retrospective cohort study of patients who underwent PMEG from 2009 to 2021 in a single centre, investigational device exemption trial. Thrombus burden was measured as a percentage of luminal volume using pre-operative computed tomography scans from the lowest renal artery to the level of the aortic bifurcation using centreline reconstruction software. Morphology was documented by the presence of finger like projections. Univariable and multivariable analyses evaluated the impact on peri-operative and long term outcomes.

RESULTS

Volumetric and morphological measures of thrombus burden were assessed in 142 patients; 40.1% of the cohort were classified as having a high thrombus burden (≥ 50% luminal volume) on volumetric assessment and 22.5% had finger like projections on morphological assessment. Type II endoleak was more frequently observed in those with low thrombus burden (60.0% vs. 33.3%; p = .008) and persisted after multivariable analysis (odds ratio 2.5, 95% confidence interval 1.1 - 5.8), but there were no other statistically significant differences in peri-operative adverse events or late outcomes, including sac behaviour, freedom from re-intervention, and overall survival when stratifying thrombus burden by quantitative or qualitative measures. There were no observed differences in operative or anatomical characteristics, including landing zone characteristics and rates of inferior mesenteric artery patency.

CONCLUSION

While thrombus burden and morphology were not associated with adverse peri-operative events or survival, low thrombus burden was associated with an increase in type II endoleak. These findings suggest that thrombus burden should not deter treatment for patients requiring PMEG.

Trends and outcomes over time with fenestrated and branched endovascular aortic repair in the United States Aortic Research Consortium

OBJECTIVE

To characterize trends and outcomes with fenestrated and branched endovascular aortic repair (F/B-EVAR) performed at centers participating in the US Aortic Research Consortium.

METHODS

F/B-EVARs performed in 10 prospective, nonrandomized, physician-sponsored investigative device exemption studies from 2015 to 2023 were studied retrospectively. Outcomes included 30-day major adverse event (MAE) and 1-year secondary reintervention. Outcome determinants were modeled with mixed effects multivariable regression. Adjusted observed minus expected cumulative sum analysis was used to evaluate outcomes achieved over time.

RESULTS

In the study period, 2377 patients underwent F/B-EVAR. The median follow-up was 2.3 years (interquartile range [IQR], 0.7-3.5 years). The proportion of thoracoabdominal aneurysms (P = .01) and aortic dissections (P = .001) increased over the study period while technical failure rates (P = .6) and length of hospital stay (P = .1) remained stable. Fusion imaging (P = .0005), low-profile devices (P < .0001), and completely transfemoral repair (P = .0005) were adopted increasingly over time. There were decreases in fluoroscopy time, procedure time, radiation dosage, and blood loss throughout the study (all P < .0001). Adjusted 30-day survival was 99.6% (IQR, 99.3%-99.8%) and MAE occurred in 240 (10%). MAE determinants included age (odds ratio [OR], 1.3 per 10-years; 95% confidence interval [CI], 1.1-1.6; P = .005), estimated glomerular filtration rate (OR, 0.9 per 10-mL/min/1.73 m2; 95% CI, 0.82-0.95; P = .001), thoracoabdominal aneurysm (OR, 1.8; 95% CI, 1.3-2.6; P = .002), operative time (OR, 1.04 per 10 minutes; 95% CI, 1.03-1.06; P < .0001), and technical failure (OR, 3.0; 95% CI, 1.7-5.1; P = .0001). The cumulative rate of 30-day MAE remained stable, reflecting expected outcomes rates. The 1-year reintervention rate was 18% (n = 435). Secondary intervention determinates included patient-specific device use (OR, 0.4; 95% CI, 0.28-0.65; P = .045), technical failure (OR, 3.1; 95% CI, 1.9-5.3; P < .0001), total target vessels (OR, 1.3 per vessel; 95% CI, 1.05-1.6; P = .002), and prior aortic dissection (OR, 1.9; 95% CI, 1.3-2.6; P = .0005). The cumulative rate of 1-year reintervention remained stable during the study period.

CONCLUSIONS

Data from multiple US centers demonstrate that F/B-EVAR can be performed safely and with acceptable outcomes. Despite increasing repair extent and complexity, the rates of technical failure, adverse events, and reintervention remained stable, likely driven, in part, by evolutions in minimally invasive techniques.

The Role of Dynamic Computed Tomography Angiography in Endoleak Detection and Classification After Endovascular Aneurysm Repair: A Comprehensive Review

Backgroud: The use of dynamic computed tomography angiography (dCTA) for the detection of endoleaks in patients who underwent endovascular repair of abdominal aortic aneurysms is gaining interest. This study aims to provide an overview of the current applications of dCTA technologies in vascular surgery. Methods: We performed a comprehensive review by searching in the PubMed database and Cochrane Library (last search: 1 November 2024). We included studies considering endoleak investigation after endovascular aneurysm repair (EVAR). We included papers that reported the outcome of applications of dCTA, excluding case reports or very limited case series (≤4). Finally, 14 studies regarding 377 computed tomography angiographies (CTA) were included and evaluated. Results: Persistent perfusion of the aneurysm sac is the most common complication after EVAR. Imaging-based surveillance post-EVAR is essential with the aim of early detection, characterization, and localization of endoleaks to guide therapeutic intervention or follow-up. dCTA detected 36 type I endoleaks versus 16 identified with standard CTA and 138 versus 95 type II endoleaks. Conclusions: The emergence of dCTA offers a promising solution through enhanced temporal resolution, allowing the visualization of real-time flow dynamics within the aneurysmal sac essential to establishing endoleak treatment or post-EVAR follow-up.

Modified fenestrated/branched endovascular aortic repair with short bridging stent to treat complex aortic dissection

Objectives

This study aims to improve fenestrated/branched endovascular aortic repair (F/B EVAR) through fabricating physician-modified stent grafts (PMSG) with short bridging stent to treat complex aortic dissection.

Methods

From November 2018 to January 2024, a total of 82 aortic dissection patients were treated by F/B EVAR combined with short bridging stents, including 19 aortic arch dissection patients and 63 thoracoabdominal aortic dissection patients. Inner or outer short bridging stents were applied to fabricate PMSG with the help of 3D-printing models intraoperatively. All patients underwent postoperative evaluation by enhanced computed tomography in follow-up.

Results

All aortic dissections were successfully repaired. In aortic arch group, the average operative time was 289.2 ± 88.8 min. The perioperative mortality rate was 5.3%. The total reintervention rate was 5.3%. The average follow-up duration of 36.2 ± 9.5 months. The total incidence of endoleak after surgery was 15.8%. In thoracoabdominal aorta group, the average operative time was 345.5 ± 112.0 min. The perioperative mortality rate was 1.6%. The total reintervention rate was 1.6%. The average follow-up duration of 32.4 ± 19.2 months. The total incidence of endoleak after surgery was 11.1%.

Discussion

The application of short bridging stents has shown promising results in reducing endoleak rates after F/B EVAR. 3D-printing is a feasible way to assist the precise fenestration and design of short bridging stents. However, the safety and reliability of this method need to be further validated.

Type II endoleaks after fenestrated/branched endografting for juxtarenal and pararenal aortic aneurysms

OBJECTIVE

Persistent type II endoleaks (pEL2s) are not uncommon after endovascular aneurysm repair and their impact on long-term outcomes is well-documented. However, their occurrence and natural history after fenestrated/branched endografting (F/B-EVAR) for juxtarenal and pararenal aneurysms (J/P-AAAs) have been scarcely investigated. Aim of this study was to report incidence, risk factors, and natural history of pEL2 after F/B-EVAR in J/P-AAAs.

METHODS

Between 2016 and 2022, all J/P-AAAs undergoing F/B-EVAR were prospectively collected and retrospectively analyzed. EL2 were assessed at the completion angiography, at 30 days and after 6 months as primary outcomes. Preoperative risk factors for pEL2, follow-up survival, freedom from reinterventions (FFR) and aneurysm shrinkage (≥5 mm) were considered as secondary outcomes.

RESULTS

Of 132 patients, there were 88 (67%) JAAAs and 44 (33%) PAAAs. Seventeen EL2 (13%) were detected at the completion angiography and 36 (27%) at 30-day computed tomography angiography. The mean follow-up was 28 ± 23 months. Eleven (31%) EL2 sealed spontaneously within 6 months and three new cases were detected, for an overall of 28 pEL2/107 patients (26%) with available radiological follow-up of ≥6 months. Preoperative antiplatelet therapy (odds ratio, 4.7; 95% confidence interval [CI[, 1-22.1; P = .05), aneurysm thrombus volume of ≤40% and six or more patent aneurysm afferent vessels (odds ratio, 7.2; 95% CI, 1.8-29.1; P = .005) were independent risk factors for pEL2. The estimated 3-year survival was 80%, with no difference between cases with and without pEL2 (78% vs 85%; P = .08). The estimated 3-year FFR was 86%, with no difference between cases with and without pEL2 (81% vs 87%; P = .41). Four cases (3%) of EL2-related reinterventions were performed. In 65 cases (49%), aneurysm shrinkage was detected. pEL2 was an independent risk factor for absence of aneurysm shrinkage during follow-up (hazard ratio, 3.2; 95% CI, 1.2-8.3; P = .014). Patients without shrinkage had lower follow-up survival (64% vs 86% at 3-year; P = .009) and FFR (74% vs 90% at 3 years; P = .014) than patients with shrinkage.

CONCLUSIONS

PEL2 is not infrequent (26%) after F/B-EVAR for J/P-AAAs and is correlated with preoperative antiplatelet therapy, aneurysm thrombus volume of ≤40%, and six or more patent sac afferent vessels. Patients with pEL2 have a diminished aneurysm shrinkage, which is correlated with lower follow-up survival and FFR compared with patients with aneurysm shrinkage.

Plug-Based Embolization Techniques of Aortic Side Branches during Standard and Complex Endovascular Aortic Repair

Vascular plugs are an evolving family of vessel occluders providing a single-device embolization system for large, high-flow arteries. Nitinol mesh plugs and polytetrafluoroethylene membrane plugs are available in different configurations and sizes to occlude arteries from 3 to 20 mm in diameter. Possible applications during complex endovascular aortic procedures are aortic branch embolization to prevent endoleak or to gain an adequate landing zone, directional branch occlusion, and false lumen embolization in aortic dissection. Plugs are delivered through catheters or introducers, and their technical and clinical results are comparable to those of coil embolization. Plugs are more accurate than coils as repositionable devices, less prone to migration, and have fewer blooming artifacts on postoperative computed tomography imaging. Their main drawback is the need for larger delivery systems. This narrative review describes up-to-date techniques and technology for plug embolization in complex aortic repair.