Technical Challenges Encountered During Deployment of the Ovation Abdominal Aortic Stent-Graft System

A Misdiagnosed Case of Endoleak Type-III Caused by Inadvertent Bilateral Limb Insertion in the Same Limb Gate of the Ovation Endograft

We describe an infrequent case of endoleak Type-III due to an unrecognized, inadvertent bilateral limb deployment into the same limb gate of the Ovation aortic endograft, accompanied by thrombosis and acute ischemia. The following computed tomography angiography revealed the open limb gate with the characteristic of radio-opaque polymer in the sealing rings. Intraoperative angiographies via the brachial route identified the open limb gate and facilitated the successful use of an occluding plug to manage the Type-III endoleak.

Meta-Analysis of the Crossed Versus Standard Limb Configuration in Endovascular Aneurysm Repair

OBJECTIVE

To investigate whether the crossed-limb technique confers better or worse clinical outcomes compared to the standard straight limb configuration in standard endovascular aneurysm repair (EVAR).

METHODS

We conducted a systematic review to identify studies comparing outcomes of EVAR with the crossed versus standard limb configuration. MEDLINE, EMBASE, CINAHL, and CENTRAL were searched in March 2021 using the Healthcare Databases Advanced Search interface developed by the National Institute for Heath and Care Excellence. The risk of bias was assessed with the Newcastle-Ottawa scale (NOS) and the Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) tool. Summary estimates were calculated using the odds ratio (OR), risk difference (RD), or mean difference (MD) and 95% confidence interval (CI), applying the Mantel-Haenszel or inverse variance statistical method. Random-effects models were employed.

RESULTS

Four observational studies qualified for inclusion, reporting a total of 1132 patients. All presented contemporary experiences. Baseline clinical characteristics were largely similar between patients with and without the crossed-limb configuration, but the anatomy tended to be less favourable in patients treated with the crossed-limb technique. No statistically significant difference was found in the primary outcomes: limb occlusion (OR 1.44, 95% CI 0.65 - 3.19), type Ib endoleak (RD 0.01, 95% CI -0.03 - 0.04), type III endoleak (RD 0.01, 95% CI -0.01 - 0.03); or secondary outcomes: perioperative mortality (RD 0.00, 95% CI -0.03 - 0.03), type Ia endoleak (RD 0.00, 95% CI -0.03 - 0.02), type II endoleak (OR 1.38, 95% CI 0.51 - 3.74), procedure duration (MD 18.07 min, 95% CI -1.14-37.29). Inconsistency across studies was low for all outcomes. The studies were judged to be of high quality on the NOS. The main bias identified using the ROBINS-I tool was due to confounding.

CONCLUSIONS

The crossed-limb technique was not found to confer inferior clinical outcomes in the medium term compared to the standard limb configuration in patients who undergo standard EVAR.

Comparison of manual versus robot-assisted contralateral gate cannulation in patients undergoing endovascular aneurysm repair

PURPOSE

Robotic endovascular technology may offer advantages over conventional manual catheter techniques. Our aim was to compare the endovascular catheter path-length (PL) for robotic versus manual contralateral gate cannulation during endovascular aneurysm repair (EVAR), using video motion analysis (VMA).

METHODS

This was a multicentre retrospective cohort study with fluoroscopic video recordings of 24 EVAR cases (14 robotic, 10 manual) performed by experienced operators (> 50 procedures), obtained from four leading European centres. Groups were comparable with no statistically significant differences in aneurysm size (p = 0.47) or vessel tortuosity (p = 0.68). Two trained assessors used VMA to calculate the catheter PL during contralateral gate cannulation for robotic versus manual approaches.

RESULTS

There was a high degree of inter-observer reliability (Cronbach's α > 0.99) for VMA. Median robotic PL was 35.7 cm [interquartile range, IQR (30.8-51.0)] versus 74.1 cm [IQR (44.3-170.4)] for manual cannulation, p = 0.019. Robotic cases had a median cannulation time of 5.33 min [IQR (4.58-6.49)] versus 1.24 min [IQR (1.13-1.35)] in manual cases (p = 0.0083). Generated efficiency ratios (PL/aorto-iliac centrelines) was 1.6 (1.2-2.1) in robotic cases versus 2.6 (1.7-7.0) in manual, p = 0.031.

CONCLUSION

Robot-assisted contralateral gate cannulation in EVAR leads to decreased navigation path lengths and increased economy of movement compared with manual catheter techniques. The benefit could be maximised by prioritising robotic catheter shaping over habituated reliance on guidewire manipulation. Robotic technology has the potential to reduce the endovascular footprint during manipulations even for experienced operators with the added advantage of zero radiation exposure.

Preliminary experience with the use of ultra-low profile endografts

PURPOSE

We aimed to report a preliminary single-center experience of elective endovascular aortic repair (EVAR) using ultra-low profile (ULP) endografts of 14 F outer diameter.

METHODS

Data of 67 consecutive patients who underwent EVAR using either Ovation (group A, n=30) or Incraft (group B, n=37) endografts were retrospectively analyzed.

RESULTS

Aorto-iliac anatomy was significantly different between the two groups, as patients of group A had a greater thrombotic apposition on proximal aortic neck (thrombus thickness: 7.2±1 mm vs. 3.3±1.6 mm, P = 0.042; percentage of the circumference covered by thrombus: 45.2%±10.4% vs. 18.7%±10.6%, P = 0.0003), while patients of group B had a more angulated proximal neck in the coronal axis (35.9°±6.4° vs. 16.7°±5°, P = 0.012). Procedural success was 93.3% and 97.3%, respectively, in groups A and B. One patient in group A required an immediate conversion to open surgery for persistent occlusion of both iliac limbs. Another patient required implantation of a conical endograft with a femoro-femoral right-to-left bypass for occlusion of the contralateral gate during the cannulation. In group B, one intraoperative type Ia endoleak was immediately corrected. Neither deaths nor major adverse events were recorded within 30-days. During a median follow-up of 15.2 months (range, 1-56.7 months) two type Ia endoleaks in group A required open conversion after 12.1 and 40.5 months, respectively. Three patients in group B required a reintervention after 30 days. Neither deaths nor aortic ruptures were recorded during follow-up.

CONCLUSION

Both ULP endografts showed satisfying early and mid-term results.

Endovascular aneurysm repair with the Ovation TriVascular Stent Graft System utilizing a predominantly percutaneous approach under local anaesthesia

OBJECTIVE

To present our experience with the Ovation Abdominal Stent Graft System (TriVascular Inc., Santa Rosa, CA) during endovascular aneurysm repair (EVAR) and compare results according to the type of anaesthesia.

METHODS

We conducted a single-centre retrospective study including patients who underwent EVAR using the Ovation endograft between May 2011 and July 2014. Outcome was evaluated regarding pre-, peri- and immediate postoperative and follow-up measures. Overall results are reported, while additional analysis was performed to compare the outcome between groups of patients undertaking either local or regional/general anaesthesia (LA vs RGA).

RESULTS

66 patients were included. Median follow-up was 13 months (range, 1-39 months). Median age was 72 years and median abdominal aortic aneurysm diameter was 58 mm (range, 54-100 mm). Technical success was 63 (95%), while there were 2 (3%) conversions to open surgery. A total percutaneous approach was used in 50/66 (76%) cases. Overall, 9/66 (14%) subjects suffered from any kind of morbidity. Median hospitalization was 3 days (range, 1-16 days). Immediate and midterm mortality rate was 0%. No endoleak Type I, III, IV or stent migration was observed. There were 8 (13%) Type II endoleaks. Overall, additional endovascular procedures were required in 6 (9%), while surgery was performed in 4 (6%) patients. 44 (67%) patients underwent LA and 22 (23%) RGA. Differences between groups were significant for procedural time (85 vs 107 min; p < 0.001), percutaneous access (91% vs 45%; p < 0.001) and systematic complications (2.3% vs 14%; p = 0.05).

CONCLUSION

EVAR with the use of the Ovation endograft shows promising short-term and midterm results regarding safety and effectiveness. Completion of the procedures under LA using a total percutaneous approach seems advantageous and may be used in routine practice.

ADVANCES IN KNOWLEDGE

The Ovation Abdominal Stent Graft System is an ultra-low profile stent graft system that allows percutaneous deployment for EVAR and offers excellent overall efficacy and safety. Totally percutaneous EVAR under LA seems advantageous and may be used as a routine with this specific endograft.

Emergent conversion of the Ovation Stent Graft System to aortouniiliac modification via occlusion of a unilateral internal iliac artery with a stentgraft as a bailout solution

Purpose

To present a case of inadvertent collapse of the contralateral limb gate caused by misorientation during the deployment of the Ovation Abdominal Stent Graft System in a narrow aortic lumen and the bailout conversion to aortouniiliac modification, using a covered stent to exclude the orifice of the internal iliac artery (IIA).

Technique description

Despite the repeated efforts from the femoral and brachial site, the collapsed/occluded contralateral limb gate could not be catheterized. In order to exclude successfully the orifice of the IIA, an oversized stentgraft was placed immediately at the common-to-external iliac artery (CIA-EIA) transition followed by peripheral ligation of the latter. The procedure was completed with crossover femorofemoral bypass.

Conclusion

Occlusion the IIA orifice with an oversized stentgraft in the CIA-EIA transition can be considered as a safe, simple, fast, and efficient bailout maneuver, followed by EIA ligation and crossover bypass.

Initial single-center experience with the Ovation stent-graft system in the treatment of abdominal aortic aneurysms: application to challenging iliac access anatomies

BACKGROUND

To present our preliminary results with the Ovation(™) abdominal stent-graft system in abdominal aortic aneurysms (AAA) with narrow (≤7 mm) or angulated iliac vessels.

METHODS

From April 2012 to January 2014, 42 patients (97% men; mean age, 71 years; range, 55-89 years) with AAAs of 55.5 mm (50-79 mm) were treated with the Ovation device. Primary end points included technical success and freedom from early secondary interventions, any type of endoleak, and aneurysm-related death. Limb occlusion was studied with respect to iliac access diameter and angulation. Iliac angulation between 90° and 120° or <90° was considered moderate or severe, respectively.

RESULTS

The postoperative follow-up was 7.8 ± 4.6 months (mean ± standard deviation). Infrarenal neck angulation was 26° ± 26°. AAA neck length and diameter were 27.3 ± 10.5 and 24.1 ± 3.2 mm, respectively. Forty-five percent of patients had at least 1 vessel of ≤7-mm diameter, and almost half of patients (24 of 44) had at least 1 iliac artery of moderate or severe angulation. Technical and treatment success were 100% and 95%, respectively. No stent-graft migration or type I, III, or IV endoleaks occurred. Type II endoleaks were identified in 5 patients, leading to sac enlargement in 2 and necessitating an embolization attempt that was unsuccessful in 1 case. No limb occlusion occurred, irrespective of the iliac diameter or angulation.

CONCLUSIONS

Our 1-year results of the Ovation stent-graft system demonstrate excellent safety and effectiveness. The easy navigation through highly angulated and stenosed iliac vessels ensures high technical success in cases of challenging iliac anatomy. Follow-up is ongoing.