Technical Feasibility and Safety of a Snare-Less, EVAR-First Technique for Iliac Branch Endoprosthesis

OBJECTIVE

The purpose of this study was to evaluate the technical feasibility, safety, and early outcomes of a snare-less, endovascular abdominal aortic aneurysm repair (EVAR)-first technique (SET) for iliac branch endoprosthesis (IBE) placement.

METHODS

We retrospectively reviewed all patients who received IBEs between July 2018 and March 2022. Patients were divided into 2 categories based on method of IBE deployment: SET or Standard. Primary endpoints were technical success, major adverse events, mortality, reintervention, internal iliac artery (IIA) patency, and freedom from IIA branch instability. Technical success was defined by successful deployment of both the EVAR and the IBE with maintained patency of the IIA and no stent graft migration.

RESULTS

There were 20 patients (90% male, median age 72 [65.4-74.5] years) who underwent IBE placement. Among these, 5 (33.3%) underwent SET to treat 5 common iliac artery (CIA)/IIA aneurysms, while the remaining 15 (66.7%) underwent standard IBE deployment with through-and-through femoral access (n=13) or trans-brachial access (n=2) to treat 19 CIA/IIA aneurysms. Overall median renal to iliac bifurcation length was 169 (152-177) mm, with 9 patients falling short of the minimum of 165 mm for on-label IBE placement. Median contrast used was 148 (120-201) mL, fluoroscopy time 42.8 (35.0-49.8) minutes, estimated blood loss 200 (100-275) mL, and procedure time 192 (167-246) minutes, with no significant differences between the 2 groups. Technical success was achieved in 100% of cases. At 30 days, there were no mortalities or major adverse events in either group; there were 100% IIA patency, no IIA instability, and no reinterventions in both groups. Median follow-up in the SET group was 5.7 (5.5-6.2) months, with 1 death at 6 months and 1 type 1B endoleak at 6 months requiring reintervention. Median follow-up for the Standard group was 1.6 (0.8-2.1) years with 2 non-aneurysm-related deaths and no reinterventions at 1 year.

CONCLUSIONS

SET for IBE is a safe and effective approach that decreases technical complexity and mitigates anatomic barriers to IBE placement.

CLINICAL IMPACT

SET for IBE is a safe and effective approach to IBE placement that decreases technical complexity. A critical component to this technique is a large bore sheath with a stiff steerable tip. Importantly, this approach also mitigates anatomic barriers to IBE placement, expanding applicability of IBE technology to patients who may be otherwise ineligible.

Predicting Features of Visceral Stent Failure in Fenestrated Endovascular Aortic Aneurysm Repair

PURPOSE

Visceral stents in fenestrated endovascular aortic repair (FEVAR) have a significant risk of complications and carry a considerable burden of reinterventions. The aim of this study is to identify preoperative and intraoperative predictors of visceral stent failure.

MATERIALS

A retrospective review of 75 consecutive FEVARs in a single center from 2013 to 2021 was undertaken. Data on mortality, stent failure, and reintervention pertaining to 226 visceral stents were collected.

METHODS

Anatomical features including aortic neck angulation, aneurysm diameter, and angulation of target viscerals were obtained from preoperative computed tomography (CT) scans. Stent oversizing and intraprocedural complications were recorded. Postoperative CT scans were analyzed to determine the length of cover of target vessels.

RESULTS

Only bridging stents through fenestrations to visceral vessels were considered; 28 (37%) cases had 4 visceral stents, 24 (32%) had 3, 19 (25%) had 2, 4 (5%) had 1. Thirty day mortality was 8%, a third of which was related to visceral stent complications. Intraprocedural complexity was documented during the cannulation of 8 (3.5%) target vessels, with a technical success rate of 98.7%. A significant endoleak or visceral stent failure was identified in 22 stents (9.8%) postoperatively, of which 7 (3%) had in-patient reintervention within 30 days. Further reinterventions at 1, 2, and 3 years were 12 (5.4%), 2 (1%), and 1 (0.4%), respectively. Most reinterventions were for renal stents (n=19, 86%). A smaller stent diameter and a shorter length of visceral stent were significant predictors of failure. No other anatomical feature or stent choice was found to be a significant predictor of failure.

CONCLUSIONS

The modality of visceral stent failures varies, but renal stents with a smaller diameter and/or shorter length are more likely to fail over time. Their complications and reinterventions are common and carry a significant burden; therefore, close surveillance must be continued long term.

CLINICAL IMPACT

With this work we share the methodology adopted at our centre to treat juxtarenal aneurysm with FEVAR. Thanks to this detailed review of anatomical and technical features we provide guidance for endovascular surgeons to face hostile aneurysm with peculiar visceral vessels anatomy. With our findings will also motivate industries in their attempt to produce improved technologies able to overcome issues identified in this paper.

Realignment of Migrated Celiac Stent Graft After Branched Stent Graft Implantation Through Retrograde Cannulation of the Superior Mesenteric Artery Using a Single Vascular Access

PURPOSE

The purpose of the study was to present an endovascular management of a type IIIc endoleak (EL) in a patient with migration of the bridging stent graft of the celiac trunk (CT) after branched aortic aneurysm repair with retrograde cannulation of the superior mesenteric artery (SMA).

TECHNIQUE

The therapy was applied in a 62-year-old man who underwent a branched EVAR 2 years ago. Meanwhile, the patient was treated due to type Ia EL 6 months ago. The patient suffered in the last days from unclear hemorrhage clinically correlated with weakness. In the computed tomography angiography (CTA), an EL IIIc with a migration of the bridging stent graft from the CT branch was displayed. As vascular access, the left axillar artery was used. Due to the misaligned bridging stent graft, an antegrade cannulation was impossible, so cannulation was performed retrograde through the SMA using pancreaticoduodenal and gastroduodenal arteries. Thereafter, the EL could be repaired with bridging stent grafts. The postinterventional control showed a satisfying reconstruction without EL or embolization.

CONCLUSION

Most of the complications such as type IIIc EL after complex endovascular repair can also be treated endovascularly. This sophisticated treatment requires that necessary materials and experience are available.

In Vitro Geometry Analysis of Fenestrations in Endovascular Aneurysm Repair

PURPOSE

Changes in the flared end of balloon-expandable covered stent (BECS) may precede BECS-associated complications but are not regularly assessed with computed tomographic angiography (CTA) after fenestrated endovascular aneurysm repair (FEVAR). Validation of the flare geometric analysis (FGA) and assessment of intraobserver and interobserver variability are investigated in this study.

METHODS

Two series of 3 BeGraft BECSs (Bentley InnoMed GmbH, Hechingen, Germany) and 1 series of 3 Advanta V12 BECSs (Getinge AB, Göteborg, Sweden) were deployed in 3 side branches (45°, 60°, and 90° aortic branch angles) of an aorta phantom model. A standard post-FEVAR CTA scan was acquired. Computed tomographic angiography-derived measurements consisted of centerline reconstructions and placement of 3-dimensional coordinate markers by 2 observers in a vascular workstation. Flare geometric analysis calculates 3 BECS parameters: the circumferential flare-to-fenestration distance (FFD), which is the distance from the proximal end of the flare to fenestration, and diameters at the proximal end of the flare (Dflare) and at the fenestration (Dfenestration). Computed tomographic angiography-derived measurements were validated against microscopy measurements. Bland-Altman plots were used to determine the intraobserver and interobserver variability of the BECS parameters and intraclass correlation coefficient (ICC).

RESULTS

For each BECS, the FFD at 4 equidistant quadrants of the circumference, Dflare, and Dfenestration were calculated. The mean difference and repeatability coefficient (RC) of the validation were 0.8 (2.1) mm for FFD, 0.4 (1.0) mm for Dflare, and -0.2 (1.2) mm for Dfenestration. The mean intraobserver and interobserver difference (RC) was 0.5 (1.6) mm and 0.7 (2.6) mm for FFD, 0.1 (0.6) mm and 0.1 (0.7) mm for Dflare, and -0.1 (0.8) mm and -0.8 (1.0) mm for Dfenestration. The mean ICC of intraobserver variability was 0.86 for FFD, 0.94 for Dflare, and 0.78 for Dfenestration. The mean ICC of interobserver variability was 0.77 for FFD, 0.92 for Dflare, and 0.48 for Dfenestration.

CONCLUSION

This study showed that FGA of the flared ends of BECS can be performed with high accuracy in a phantom model, with good intraobserver and interobserver variability. Flare geometric analysis can be used to determine flare geometry of the BECS on standard post-FEVAR CTA scans.