Aneurysm Growth After Endovascular Sealing of Abdominal Aortic Aneurysms (EVAS) with the Nellix Endoprosthesis.

OBJECTIVE: The aim of this study was to measure the incidence of post endovascular aneurysm sealing (EVAS) abdominal aortic aneurysm (AAA) growth, and its association with stent migration, in a cohort of patients with differing compliance to old and new Instructions For Use (IFU). METHODS: A retrospective single centre study was conducted to review the computed tomography (CT) and clinical data of elective, infrarenal EVAS cases, performed as a primary intervention, between December 2013 and March 2018. All included patients had a baseline post-operative CT scan at one month and at least one year follow up. The primary outcome measure was the incidence of AAA growth and its association with stent migration. AAA growth was defined as a ≥5% increase in aortic volume between the lowermost renal artery and the aortic bifurcation post EVAS at any time during follow up, in comparison to the baseline CT scan. Migration was defined according to the ESVS guidelines, as > 10 mm downward movement of either Nellix stent frame in the proximal zone. RESULTS: Seventy-six patients were eligible for inclusion in the study (mean age 76 ± 7.4 years; 58 men). AAA growth was identified in 50 of 76 patients (66%); adherence to IFU did not affect its incidence (mean growth within IFU-2016 compliant cohort vs. non-compliant: 16% vs. 13%, p = .33). Over time, the incidence of AAA growth increased, from 32% at one year to 100% at four years. AAA growth by volume was progressive (p < .001), as its extent increased over time. Migration was detected in 16 patients and there was a statistically significant association with AAA growth (13 patients displayed migration and AAA growth, p = .036). CONCLUSION: Patients treated with EVAS are prone to AAA growth, irrespective of whether their aortic anatomy is IFU compliant. AAA growth by volume is associated with stent migration. Clinicians should continue close surveillance post EVAS, regardless of whether patients are treated within IFU.

Stent Frame Movement Following Endovascular Aneurysm Sealing in the Abdominal Aorta.

PURPOSE: To investigate the incidence and extent of stent frame movement after endovascular aneurysm sealing (EVAS) in the abdominal aorta and its relationships to aneurysm growth and the instructions for use (IFU) of the Nellix endograft. METHODS: A retrospective single-center study was conducted to review the clinical data and computed tomography (CT) images of 75 patients (mean age 76±7.6 years; 57 men) who underwent infrarenal EVAS and had a minimum 1-year follow-up. The first postoperative CT scan at 1 month and the subsequent scans were used to measure the distances between the proximal end of the stent frames and a reference visceral vessel using a previously validated technique. Device migration was based on the Society of Vascular Surgery definition of >10-mm downward movement of either Nellix stent frame in the proximal landing zone; a more conservative proximal displacement measure (downward movement ⩾4 mm) was also recorded. Patients were categorized according to adherence to the old (2013) or new (2016) Nellix IFU. Aneurysm diameter was measured for each scan; a change ⩾5 mm was deemed indicative of aneurysm growth. RESULTS: Over a median follow-up of 24 months (range 12-48), proximal displacement ⩾4 mm occurred in 42 (56%) patients and migration >10 mm in 16 (21%), with similar incidences in the right and left stent frames. Proximal displacement was significantly more frequent among patients whose anatomy did not conform to any IFU (p=0.025). Presence of aneurysm growth ⩾5 mm was observed in 14 (19%) patients and was significantly associated with proximal displacement ⩾4 mm (p=0.03). CONCLUSION: Infrarenal EVAS may be complicated by proximal displacement and migration, particularly when performed outside the IFU. The definition of migration used for endovascular aneurysm repair may be inappropriate for EVAS; a new consensus on definition and measurement technique is necessary.

Clinical Outcome after Endovascular Sealing of Abdominal Aortic Aneurysms: A Retrospective Cohort Study.

BACKGROUND: The aim of this study is to present the clinical outcome of endovascular aneurysm sealing (EVAS) with the Nellix endoprosthesis in patients with abdominal aortic aneurysms treated in our institution. METHODS: This is a retrospective, single center, observational cohort study. A departmental database was interrogated to extract demographics, clinical information, and outcome of all patients treated with EVAS between December 2013 and December 2015. Outcome measures included technical success (successful device deployment and absence of any endoleak at completion angiography), mortality, major complications, incidence of endoleaks, aneurysm rupture, and reintervention. RESULTS: Sixty-five patients (49 men) with a mean (standard deviation) age of 78 (6.9) years were successfully treated with EVAS, with no 30-day mortality. The cohort included 1 patient with ruptured aneurysm, 9 patients with late complications of previous aortoiliac repairs (2 open, 7 endovascular), and 4 patients who required a total of 9 visceral chimneys for juxtarenal aneurysms. Six patients (9%) suffered major postoperative complications and 4 (6%) required intervention. There were no early or late endoleaks or aneurysm ruptures. After a median (range) follow-up of 12 (0-24) months, there was no aneurysm-related mortality; 2 patients (3%) required late aneurysm-related interventions. CONCLUSIONS: EVAS can be performed with good outcomes up to 2 years postoperatively. Longer follow-up on larger cohorts is needed to prove the efficacy of this technique.

Development of a Scoring System for the Prediction of Early Graft Failure after Peripheral Arterial Bypass Surgery.

BACKGROUND: An occluded lower limb arterial bypass is associated with poor prognosis for the limb. Currently, no risk assessment method to estimate the risk of early graft failure exists. Aim of this study was to investigate the effect of various potential factors on early graft failure of infrainguinal bypass surgery and to develop a risk-scoring model to predict it. METHODS: A prospective observational clinical study was performed. One hundred infrainguinal bypass procedures (60 autologous and 40 synthetic grafts), throughout a 3-year period were included. Nearly, 84 patients suffered by chronic limb ischemia, whereas 16 by acute limb ischemia or popliteal aneurysm disease. Various possible factors including demographic data, atherosclerosis predisposing factors, and technical details of the procedure were examined as possible causes of early graft failure. Using a combination of univariable and multivariable analysis techniques, the most significant factors were extracted, and a simple predicting risk-scoring system of early graft failure was calculated. RESULTS: The overall early graft failure rate was 14%. The factors related to it at a statistically significant level, 0.05, were the female gender, a bypass performed after a previous ipsilateral lower limb angioplasty, a redo procedure on the same limb, and a distal anastomosis at an inframalleolar level (pedal bypass). After internal validation, the FARP2-predicting scoring system was formed as following: Female gender 1 point (F), bypass after a previous Angioplasty 1 point (A), Redo bypass 1 point (R), and Pedal bypass 2 points (P2). An overall score equal or greater than 2, provided an early graft failure prediction with sensitivity of 100%, specificity 86%, positive predictive value 54%, and negative predictive value of 100% (area under the receiver operator characteristic curve: 0.959). CONCLUSIONS: FARP2 is a simple scoring system for predicting early graft failure after an infrainguinal bypass procedure. Further external validation in larger populations is needed.

Endovascular Aneurysm Sealing (EVAS) Alone or in Combination with Chimney Grafts (chEVAS) for Treating Complications of Previous Endovascular Aneurysm Repair (EVAR) Procedures.

OBJECTIVE: Late complications after previous endovascular aneurysm repair (EVAR) procedures include type I/III endoleaks causing aneurysm growth and rupture. We reviewed our results from the management of such complications with endovascular aneurysm sealing (EVAS) techniques. METHODS: Analysis of our prospectively maintained aneurysm database was performed (December 2013-May 2017). Primary outcomes were: (1) success of the procedure in excluding the primary complication, (2) perioperative mortality, (3) post-operative complications and (4) survival. RESULTS: Ten consecutive patients were treated for complications of EVAR procedures performed 2-12 years previously. All patients underwent EVAS with/without chimney grafts for 6 type Ia,1 type IIIb and 3 undetermined (but presumed type IIIb) endoleaks. Overall, 19 Nellix® devices were used. The technical success with type Ia endoleaks was 100%. All sealed using proximal extension through chimney EVAS with 1 target vessel loss. There were no perioperative deaths. All but 1 type Ia endoleak remained eliminated at follow-up (range 2-29 months) as did the proven type IIIb endoleak. Two of the 3 undetermined endoleaks demonstrated continued sac expansion requiring surgical exploration by laparotomy, during which type II endoleaks were identified. CONCLUSIONS: EVAS provides effective short-term treatment of type Ia/IIIb endoleaks after EVAR. However, late complications may occur due to disease progression. LEVEL OF EVIDENCE: Level 4, case series.