Does type 1 endoleak always need to be treated?

Clinical History

This elderly lady underwent endovascular abdominal aortic aneurysm repair (EVAR) treatment for an abdominal aortic aneurysm (AAA). A type one endoleak (EL1) was detected at the end of the procedure but no further manoeuvres to solve the problem were attempted.

Imaging Findings

This 80-year-old female patient was scheduled for an EVAR for a 5.5 cm AAA. The case was quite challenging due to angulated neck (Fig.1a,b). However, it was decided to treat it with the Endurant stent-graft (Medtronic). The procedure was carried out without any significant problems, but the final angiogram showed an evident type EL1 despite repeated inflations with a conforming balloon and the addition of a proximal cuff. No extra large stents were available to increase graft apposition to the aortic neck and for this reason the procedure was stopped. The day after CT confirmed the EL1 (Fig.2a,b) and a catheter angiography, performed to enter the leak and fill it with coils, confirmed the finding (Fig.2c,d). After 5 days the patient was operated again for extra large bare stent deployment on the neck but preliminary intraoperative angiography showed complete resolution of type EL1 (Fig.3 a,b). One year CT-follow-up confirmed the absence of any EL (Fig 4).

Discussion

Endoleaks are a not unusual complication after EVAR. Type 1 EL is one of the more severe because it means a direct communication between the aortic lumen and the excluded sac with the risk of increased intrasac pressure and rupture. The incidence of type 1 EL is reported to be about 15% in a recent paper by Metha et al. The cause of type 1 EL is related to an incomplete sealing of the graft to the proximal or distal neck generally caused by rich calcium or thrombus apposition in the neck. Other causes of type 1 EL are a too low stent-graft deployment or an angulated neck as in this case. Nevertheless, based on previous cases of angulated neck in our experience, we decided to treat a challenging case as this one. There is general agreement that type 1 EL requires urgent treatment (Cao et al) because of the increased risk of rupture due to high intrasac pressure. However, in this case another proximal cuff was not considered an option because of the high risk to cover the origin of the renal arteries. An extra-large bare stent to increase graft sealing to the neck was not available at the moment and for this reason it was decided to wait and check. Type 3 or 4 EL were excluded due to the early filling around the main body of the graft before graft-limbs opacification. Furthermore clotting parameters were normal (INR 1.12, APTT 26.1). Take home messages of this case are:
if the stent-graft deployment is correct and an EL1 persists a strategy to wait and see could be suggested because after 5 days a spontaneous resolution of the leak was observed;
a strict follow-up with CT or color-Doppler ultrasound is needed and if after a few days the leak does not disappear, re-intervention is mandatory;
always consider to have extra large balloon expandable bare stents in own stock.

Differential Diagnosis List

Final Diagnosis

Spontaneous resolution of a type 1 endoleak after EVAR

URL:	https://www.eurorad.org/case/8902
DOI:	10.1594/EURORAD/CASE.8902
ISSN:	1563-4086