Multicenter Nellix EndoVascular Aneurysm Sealing system experience in aneurysm sac sealing.
Despite improvements in endograft devices, operator technique, and patient selection, endovascular repair has not achieved the long-term durability of open surgical aneurysm repair. Persistent or recurrent aneurysm sac flow from failed proximal sealing, component failure, or branch vessel flow underpins a significant rate of reintervention after endovascular repair. The Nellix device (Endologix, Irvine, Calif) employs a unique design with deployment of polymer-filled EndoBags surrounding the endograft flow lumens, sealing the aneurysm sac space and potentially reducing complications from persistent sac flow. This retrospective analysis represents the initial experience in consecutive patients treated with the device in real-world practice.
This study was performed at six clinical centers in Europe and one in New Zealand during the initial period after commercialization of the Nellix device. Patients underwent evaluation with computed tomography and other imaging modalities following local standards of care. Patients were selected for treatment with Nellix and treated by each institution according to its endovascular repair protocol. Clinical and imaging end points included technical success (successful device deployment and absence of any endoleak at completion angiography), freedom from all-cause and aneurysm-related mortality, endoleak by type, limb occlusion, aneurysm rupture, and reintervention.
During a 17-month period, 171 patients with abdominal aortic aneurysms were treated with the Nellix device and observed for a median of 5 months (range, 0-14 months). The 153 male and 18 female patients with mean age of 74 ± 7 years had aneurysms 61 ± 9 mm in diameter with an average infrarenal neck length of 28 ± 15 mm and infrarenal angulation of 37 ± 22 degrees. Technical success was achieved in all but two patients (99%); one patient had a type Ib endoleak and another had a type II endoleak. Through the last available follow-up, type Ia endoleak was observed in five patients (3%), type Ib endoleak in four patients (2%), and type II endoleak in four patients (2%). There were eight limb occlusions (5%), among which seven were evident at the 1-month follow-up visit. Aneurysm-related reinterventions were performed in 15 patients (9%). There were no aneurysm ruptures or open surgical conversions.
This first multicenter postmarket report of the Nellix device for infrarenal abdominal aortic aneurysm repair demonstrates satisfactory results during the initial learning phase of this new technology. The rate of aneurysm exclusion was high, and frequency of complications was low. More definitive conclusions on the value of this novel device await the results of the ongoing Nellix EVAS FORWARD Global Registry and the EVAS FORWARD investigational device exemption trial.
Böckler D
,Holden A
,Thompson M
,Hayes P
,Krievins D
,de Vries JP
,Reijnen MM
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Management of Nellix migration and type Ia endoleak from proximal endovascular aneurysm sealing relining to late open conversion.
Despite promising early results, midterm failures of the Nellix endovascular aneurysm sealing (EVAS) system (Endologix Inc, Irvine, Calif) have been reported at higher than expected rates. The management of proximal endoleaks and migration differs from those after conventional endovascular aortic aneurysm repair (EVAR) owing to the peculiar design of the Nellix device. In the present study, we report a monocentric experience in the management of EVAS complications using various techniques. We also performed a comprehensive review of the relevant literature on both open surgical and endovascular management of proximal failure of EVAS from the MEDLINE database.
We retrospectively analyzed the reinterventions for type Ia endoleak and migration after elective infrarenal EVAS at our institution. We collected preoperative, intraoperative, and follow-up data. Open and endovascular techniques are described. Overall survival, aortic-related mortality, and the technical success rate (rate of exclusion of endoleaks) with endovascular techniques were the primary outcomes.
We performed 101 infrarenal elective EVAS procedures from 2013 to 2018. Of the 101 patients, 20 (19.8%) had required reintervention for proximal sealing failure. The indications were type Ia (Is2, Is3) endoleak, migration >5 mm, sac expansion >5 mm, and secondary rupture. Of the 20 patients, 6 (30%) were treated with endovascular techniques-2 with a chimney Nellix-in-Nellix application and 4 with proximal relining with a covered stent. The remaining 14 patients (70%) were treated with late open conversion (OC). The average time from EVAS to reintervention was 36.1 months (range, 3-65 months). Six patients (30%) had undergone OC in an emergent setting because of secondary rupture. The technical success rate for the patients treated with endovascular reinterventions was 100%. The 30-day mortality was 20% (4 of 20), all emergent cases (four of six emergent repairs; 67%). The overall survival for the 20 patients was 75% (n = 15) at a mean follow-up of 15.1 months (range, 2-47 months). One patient had died after 7 months of non-aortic-related causes.
The high reintervention rate of the Nellix graft mandates careful evaluation for its further use with the revised instructions for use, and it should not be used off-label. OC remains the strategy of choice when managing Nellix proximal sealing failures in fit patients. Chimney Nellix-in-Nellix application and transcatheter embolization are feasible alternative techniques. Proximal relining also appears to be an effective alternative to more complex interventions, although it requires further studies for validation.
Mortola L
,Ferrero E
,Quaglino S
,Ferri M
,Viazzo A
,Manzo P
,Gaggiano A
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One-year pivotal trial outcomes of the Nellix system for endovascular aneurysm sealing.
The Nellix EndoVascular Aneurysm Sealing (EVAS) System (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) treatment whereby polymer is used to fill the AAA sac. We report 1-year results of the investigational device exemption pivotal trial.
Eligible patients were treated at 30 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with a neck length ≥10 mm and ≤60° angle, iliac artery blood lumen diameter 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine ≤2 mg/dL. Follow-up included computed tomography angiography scans at 30 days, 6 months, and 1 year that were evaluated by a core laboratory. The primary safety end point was 30-day major adverse events (MAEs), which were compared with a performance goal of <56% (the Society for Vascular Surgery open repair control group rate). The primary effectiveness end point was treatment success at 1 year, which was compared with a performance goal of >80%. Treatment success required procedural technical success and absence of AAA rupture during follow-up, conversion to open surgical repair, endoleak (type I or III) at 1 year, migration >10 mm causing complications or requiring secondary intervention, aneurysm enlargement, or secondary procedures through 1 year for resolution of endoleak, device obstruction or occlusion, or device defect.
Of 150 treated patients, 149 (99.3%) completed 1-year follow-up. The MAEs rate at 30 days was 2.7% (95% confidence interval, 0.7%-6.7%), satisfying the primary safety end point (<56%). The 1-year treatment success was 94% (95% confidence interval, 88.6%-97.4%), achieving the primary effectiveness end point (>80%). At 1 year, key secondary outcomes included 6.7% MAEs, 4.7% serious device-related events, 1.3% AAA-related mortality, 3.7% secondary interventions, and 0.7% surgical conversions. MAEs through 1 year included death (n = 6), stroke (n = 3), bowel ischemia (n = 2), renal failure (n = 2), respiratory failure (n = 2), and myocardial infarction (n =1). One iatrogenic AAA rupture occurred and one AAA rupture was reported during follow-up. AAA sac enlargement (>5 mm) was 1.5% at 1 year. Endoleaks were present in four patients (3.1%) at 1 year (1 type Ib and 3 type II). Migration >10 mm occurred in three patients (2.3%), but none required secondary intervention.
Outcomes with this novel endovascular therapy for AAA, the Nellix EVAS System, are encouraging. The primary safety and effectiveness end points have been met. Low morbidity, low mortality, and high procedural and treatment success were achieved despite the inevitability of a learning curve and unique risks associated with a new device and technique. Long-term follow-up is in progress.
Carpenter JP
,Cuff R
,Buckley C
,Healey C
,Hussain S
,Reijnen MM
,Trani J
,Böckler D
,Nellix Investigators
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