Management of Nellix migration and type Ia endoleak from proximal endovascular aneurysm sealing relining to late open conversion

ALTURA™ Stent Graft Shortening and Its Implications After EVAR

Objectives: The ALTURA™ stent graft system is designed for the treatment of abdominal aortic and/or aorto-iliac aneurysms. This study evaluates the performance of the ALTURA™ stent graft, focusing on AAA diameter, landing zones, stent graft length, and migration following endovascular aortic repair (EVAR). Methods: This is a retrospective analysis of computed tomography (CT) images focuses on patients with infrarenal abdominal aortic aneurysm (AAA) treated with the ALTURA™ stent graft system (Lombard, Ltd., Didcot, UK) at Pauls Stradins Clinical University Hospital in Riga, Latvia, and University Hospital Düsseldorf in Düsseldorf, Germany. The study population consisted of patients with asymptomatic AAAs who underwent elective treatment between January 2014 and June 2017. Follow-up CT scans were performed at one month, six months, one, two, and three years after implantation. Changes in stent graft length, aneurysm sac diameter, and the proximal and distal sealing zones were evaluated. Results: A retrospective analysis was conducted on computed tomography (CT) images from 40 patients (mean age 70.4 ± 8.5 years, 34 males, 6 females) who were treated with the ALTURA™ stent graft system for infrarenal abdominal aortic aneurysms (mean aneurysm diameter 5.6 ± 1.0 cm). The mean follow-up duration was 24.2 ± 10.6 months, with CT scans completed for all patients at one month and for 80% at one year. The mean total shortening of the stent graft one year after EVAR was 4 ± 3 mm (p < 0.001), 7 ± 5 mm after two years (p < 0.001), and 9 ± 6 mm after three years (p < 0.001). The iliac extensions shortened by 4 ± 3 mm after one year (p < 0.001), 6 ± 4 mm after two years (p < 0.001), and 8 ± 4 mm after three years (p < 0.001). Significant shortening was observed in the iliac extension, while changes in the aortic stent graft were not statistically significant. The reduction in the distal sealing zone and upward migration of the stent graft were 3 ± 3 mm after one year (p < 0.001), 5 ± 5 mm after two years (p < 0.001), and 7 ± 7 mm after three years (p < 0.001). Over the follow-up period, significant stent graft shortening and loss of the distal sealing zone were observed. However, these changes remained within a clinically acceptable range and did not lead to type I endoleak. Aneurysm sac shrinkage greater than 10 mm one year after treatment was observed in 25% of patients (p < 0.001). No aneurysm ruptures or AAA-related deaths were reported. Conclusions: Significant shortening of ALTURA™ stent graft, migration, and sealing zone reduction were observed without clinical impact after three years. However, in patients with short distal sealing zones, these changes could increase the risk of type Ib endoleak. Longer follow-up is needed to assess long-term durability.

First Case of Nellix Stent Rupture in a Huge Symptomatic Abdominal Aortic Aneurysm Who Underwent Endovascular Aneurysm Sealing 7 Years Before

PURPOSE

Despite encouraging early results, mid- and long-term follow-up of endovascular aneurysm sealing (EVAS) has shown increased rates of failure mainly associated with endoleak detection and progressive bag separation with aneurysm reperfusion.

CASE REPORT

We present the first case of a Nellix endograft stent fracture detected in a 91-year-old male patient, presenting with widespread abdominal pain, 7 years after elective treatment of an abdominal aortic aneurysm by EVAS. Considering the sudden and unexpected nature of the event, an in-depth analysis of the possible causes of this structural failure has been performed.

CONCLUSION

Material fatigue could be another significant cause of late EVAS failure and should be carefully assessed in addition to endoleak detection during follow-up.

CLINICAL IMPACT

The case presented in this article further underlines the importance of a strict long term follow-up protocol in every patients who underwent EVAS.

Combining Endovascular Aneurysm Sealing with Chimney Grafts - 5 Year Follow-Up after 47 Procedures

BACKGROUND

To evaluate longer-term results of a cohort treated with primary chimney endovascular aneurysm sealing (ChEVAS) for complex abdominal aortic aneurysms or secondary ChEVAS after failed endovascular aneurysm repair/endovascular aneurysm sealing.

METHODS

A single-center study was conducted of 47 consecutive patients (mean age 72 ± 8 years, range 50-91; 38 men) treated with ChEVAS from February 2014 to November 2016 and followed through December 2021. The main outcome measures were all-cause mortality (ACM), aneurysm-related mortality, occurrence of secondary complications and conversion to open surgery. Data are presented as the median (interquartile range [IQR]) and absolute range.

RESULTS

35 patients received a primary ChEVAS (=group I) and 12 patients a secondary ChEVAS (=group II). Technical success was 97% (group I) and 92% (group II); 30-day mortality was 3% and 8%, respectively. The median proximal sealing zone length was 20.5 mm (IQR 16, 24; range 10-48) in group I and 26 mm (IQR 17.5, 30; range 8-45) in group II, respectively. During a median time of follow-up of 62 months (range 0-88), ACM amounted to 60% (group I) and 58% (group II); aneurysm mortality was 29% and 8%, respectively. An endoleak was seen in 57% (group I: 15 type Ia endoleaks, four isolated type Ib, and 1 endoleak type V) and 25% (group II: 1 endoleak type Ia, one type II, and 2 type V), aneurysm growth in 40% and 17%, migration in 40% and 17%, resulting in 20% and 25% conversions in group I and II, respectively. Overall a secondary intervention was performed in 51% (group I) and 25% (group II), respectively. The occurrence of complications did not significantly differ between the 2 groups. Neither the number of chimney grafts, nor the thrombus ratio significantly affected the occurrence of abovementioned complications.

CONCLUSIONS

While initially delivering a high technical success rate, ChEVAS fails to provide acceptable longer-term results both in primary and secondary ChEVAS, resulting in high rates of complications, secondary interventions and open conversions.

Editor's Choice - Focused Update on Patients Treated with the Nellix EndoVascular Aneurysm Sealing (EVAS) System from the European Society for Vascular Surgery (ESVS) Abdominal Aortic Aneurysm Clinical Practice Guidelines

OBJECTIVE

After alerts on EndoVascular Aneurysm Seal (EVAS) failure were raised, the European Society for Vascular Surgery (ESVS) Abdominal Aortic Aneurysm (AAA) Clinical Practice Guidelines Writing Committee (WC) initiated a task force with the aim to provide guidance on surveillance and management of patients with implanted EVAS devices.

METHODS

Based on a scoping review of risk for late serious aortic-related adverse events in patients treated with EVAS for AAA, the ESVS AAA Guidelines WC agreed on recommendations graded according to the European Society of Cardiology (ESC) grading system.

RESULTS

EVAS has a very high incidence of late endograft migration resulting in proximal type 1 endoleak with risk of rupture, requiring open conversion with device explantation. The reported mortality rate for elective explantation varies between 0% and 14%, while acute conversion for rupture has a very dismal prognosis with a 67 - 75% mortality rate.

CONCLUSION

It is recommended that all patients in whom a Nellix device has been implanted should be identified, properly informed, and enrolled in enhanced surveillance. If device failure is detected, early elective device explantation should be considered in surgically fit patients.

A Case of Late Type Ia Endoleak After Endovascular Aneurysm Sealing Using the Nellix System: Proximal Extension with Triple Chimney and Gutter Endoleak Embolization

An 87-year-old man, who submitted to endovascular aneurysm sealing (EVAS) on 2017, presented a type Ia endoleak 2 years later, with enlargement of the aneurysmal sac. We planned an endovascular procedure of correction consisting of a proximal extension through two covered stent grafts deployed into the previous Nellix stent grafts, with associated triple chimney. However, 3 months later, he had a further 5 mm aneurysmal sac enlargement. He was submitted to angiography with coil embolization of gutters, obtaining a successfully result. At 1 and 3 months, he is free from endoleak, with a stable aneurysmal diameter.