European Conference on Embolotherapy

June 22-25 | Nice, France

Mastering Embolisation

June 22-25 | Nice, France

Mastering Embolisation

June 22-25 | Nice, France

Mastering Embolisation

June 22-25 | Nice, France

June 22-25 | Nice, France

ProgrammeET 2022 Topic HighlightsDurability of type 1 embolisation

Durability of type 1 embolisation

Dr. Fabrizio Fanelli

Speaker bio

Endoleaks (EL) represent the most frequent complication of endovascular abdominal aortic repair (EVAR). They are related to a persistent arterial communication between the aneurysm sac and the systemic circulation.

According to their origin, EL are classified into 5 types and into 2 types in relation to the location (proximal or distal). (Tab.1)

In 10-45% of cases, such complications can be associated with dilation of the aneurysm sac, necessitating an endovascular treatment in 8.7% of cases over an average period of 12 ± 13 months.1-2 Type I EL can occur in 5 – 10 % of patients after EVAR. 3

Type I EL are the most critical; they are secondary to an incorrect sealing of the stent-graft to the arterial wall. As a consequence, a direct flow goes to the aneurysmatic sac, increasing the sac pressure and, consequently, increasing the risk of rupture. The risk ratio of secondary aneurysm rupture owing to Type I EL varies from 2.0 to 7.6 %. 4

Different studies have demonstrated scant sac pressure reduction after EVAR procedures with associated type I EL, so it is mandatory to eliminate this type of endoleak whenever it is detected.

As the indications for EVAR have expanded, and more patients with shorter, wider, and/or more severely angulated necks are treated, the incidence of type I endoleaks has been reported up to 10%. 5

When proximal attachment zones are, <10 mm and/or angulations are <60°, the risk of type type I EL can be higher. 3-4 Persistent EL-I (type a) treatment is more challenging and has been reported in 2.9% to 6.9% of all EVAR procedures. 4 For this reason, immediate treatment is recommended.

Different percutaneous techniques have already been already, but none of them can be considered ideal, especially in more complex situations or in the case of a persistent endoleak, when surgical conversion may be also required. 6-11

Type I EL are routinely treated with balloon dilatation of the proximal sealing zone, with endoanchors or with cuff insertion. However, these techniques have some limitations, for example, when the landing zone is insufficient, and can fail as reported in the literature. 4

Golzarian et al 6 in 1997 proposed the use of trans-arterial embolisation also in cases of type I EL. Both liquid embolic agents (N-butyl cyanoacrylate (NBCA) – EVOH (ethylene vinyl alcohol copolymer) and coils alone or in combination can be considered valid tools.

Following this initial experience, various approaches have been proposed, such as trans-arterial, trans-lumbar and also trans-abdominal.

Choi et al 7 reported a trans-abdominal or trans-arterial approach using NBCA in 7 patients (5 type Ia, 1 type Ib, 1 type Ia/Ib) in which a primary attempt to exclude the EL failed.  For trans-arterial embolisation, selective catheterisation of the aneurysm sac was obtained with a 5-F catheter placed between the aortic wall (Ia) or iliac arterial wall (Ib) and the stent-graft. For those cases in which the trans-arterial approach failed, a percutaneous trans-abdominal was attempted. The authors reported a technical success of 86% with shrinkage or stability of the aneurysmatic sac diameter in 6 of 7 patients.

A very recent review reporting the use of liquid embolic agents as monotherapy for the treatment of type I EL after EVAR reported a technical success achieved in 189 of the 194 patients (97.9%) and clinical success achieved in 170 of the 194 patients (87.6%). 8

In addition, in patients treated with chimney endovascular aneurysm repair (ChEVAR), type Ia – gutter endoleaks remain a challenging problem with an incidence of 10.7% of cases. 9-11 In this setting, trans-arterial access to the gutter leak can be considered a valid option. The trans-lumbar technique is also feasible 2but, in some situations, positioning the patient is more challenging and can limit arterial access.

Massimi et al. 9 reported a novel trans-caval technique to treat a type I gutter endoleak in a case of three-vessel ChEVAR for a pararenal aneurysm.

In conclusion, we can affirm that type I EL represents a very complex situation. Type I EL management should take in consideration several elements, including its origin and aortic anatomy. New techniques and devices have been used to solved EL, but more studies and more data are necessary to completely validate them.



Type I:  Inadequate sealing
Ia- Proximal Landing zone
Ib- Distal landing zone
Ic- Common Iliac artery

Type II:  Backflow from aortic collaterals into the aneurysm sac
Early — Occurring within 30 days
Late — Occurring after 1 year
Persistant- Present for more than 6 months after EVAR

Type III: Secondary to structural failure of the endograft
IIIa — Component separation
IIIb — Stent fabric disturbance

Type IV:  Related to graft fabric porosity

Type V (Endotension): Continued high intra-sac pressure following EVAR without evidence of aneurysmal sac perfusion


Fabrizio Fanelli


"Careggi" University Hospital, University of Florence, Florence/IT


Prof. Fabrizio Fanelli is the director of the vascular and interventional radiology department of the University Hospital of Florence. He is a full professor of radiology and is certified by the European Board of Interventional Radiology (EBIR). An active researcher, he has participated in more than 20 clinical research-studies, authored or co-authored more than 100 scientific publications in peer-reviewed journals, authored 4 books and co-authored 19 books on radiological-interventional sciences, and has spoken at more than 500 international congresses.

Prof. Fanelli is involved in more than 90 training courses on endovascular techniques and is the organizer or co-organizer of several international and national courses. He is an active member of the Italian Society of Medical Radiology (SIRM), the European Society of Radiology (ESR), and the Cardiovascular and Interventional Radiology Society of Europe (CIRSE). He currently serves as a member of the scientific programme committee for the Interdisciplinary Endovascular Aortic Symposium (IDEAS). He is the editor of EURORAD, a publication of the vascular and interventional radiology section of ESR, and is an associate editor of JVIR and CVIR Endovascular. He is also a member of editorial board and reviewer of several other medical journals.



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  9. Massimi, Tareq M. et al. Transcaval embolization of a type I gutter endoleak after three-vessel chimney endovascular aneurysm repair. Journal of Vascular Surgery, Volume 65, Issue 5, 1515 – 1517
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  11. Kasprzak PM, Pfister K, Kuczmik W, et al. Novel technique for the treatment of Type Ia endoleak after endovascular abdominal aortic aneurysm repair. J Endovasc Ther. 2021 Aug;28(4):519-523