Ethylene–vinyl alcohol copolymer as embolic agent for treatment of type II endoleak: our experience

Outcome and technical evolution of type 2 endoleak embolization with ethylene-vinyl-alcohol copolymer

PURPOSE

This study aims to evaluate the safety and efficacy of novel approaches to type 2 endoleak access for the purpose of embolization using ethylene-vinyl-alcohol copolymer (EVOH) in patients with abdominal aortic aneurysm (AAA) sac expansion post endovascular abdominal aortic repair (EVAR).

METHODS

A retrospective review of 43 consecutive patients (mean age = 80.2 ± 6.7 years) who underwent 52 embolization procedures for type 2 endoleaks using EVOH was performed at a single institution. Catheterization of the endoleaks was achieved using the transarterial (TA) and direct translumbar approaches (DTL), in addition to the novel direct transabdominal (DTA) and perigraft (PG) approaches. Endpoints included technical success of endoleak catheterization, technical success of endoleak embolization, endoleak persistence, endoleak recurrence, AAA sac area change, and adverse events.

RESULTS

The TA, DTL, DTA, and PG approaches were used 25, 2, 14, and 19 times respectively, including nine procedures where a combination of approaches was used. The technical success rate of endoleak embolization was 98%. Five patients developed recurrent type 2 endoleaks, while five patients developed a type 1 endoleak. The persistent endoleak rate at a mean initial follow-up of 3 months was 34%. At a mean follow-up of 18 months, 58% of patients demonstrated absence of an endoleak, and 71% showed freedom from AAA sac enlargement. No major adverse events were recorded.

CONCLUSION

The DTA and PG approaches were safe and effective in this cohort of patients undergoing embolization of type 2 endoleaks with EVOH.

Direct percutaneous embolization of aneurysm sac: a safe and effective procedure to treat post-EVAR type II endoleaks

PURPOSE

To report safety and effectiveness of type II endoleak embolization, with percutaneous direct aneurysm sac puncture.

MATERIALS AND METHODS

Fifty patients, 31 male (mean age 55 ± 5), with post-EVAR type-II endoleak underwent direct percutaneous sac puncture for embolization. Procedures were performed, under local anesthesia. Sac puncture was done using a 20G needle under rotational angiography guidance. A coaxial system (4 Fr catheter + 2.7 microcatheter) was used to navigate the sac. During the follow-up period, all patients underwent contrast-enhanced ultrasound (CEUS) at 6 and 12 months.

RESULTS

Technical success, with complete exclusion of the aneurysm sac, was achieved in all cases. Time of procedure varied between 36 and 68 min (mean 51.36 min). Mean fluoroscopy time was 16.7 min. A posterior left access was used in 41 cases, posterior right access in 6 cases, and an anterior approach in 3. In 19 cases (38%), one or more feeding vessels were visualized and embolized. Sac embolization was done using Onyx plus micro-coils in 31 cases (62%) and Onyx alone in 19 cases (38%). Mean amount of Onyx was 6 ml. No complications, correlated with the direct percutaneous sac puncture, or to Onyx injection occurred. After 1-year follow-up, sac shrinkage occurred in 34 cases (68%), while in 16 patients (32%) sac size remained stable without evidence of sac perfusion.

CONCLUSION

Percutaneous direct sac embolization using Onyx in combination or not with microcoils represents a safe and valid technique to solve post-EVAR type II endoleaks.

Transcatheter embolization with Squid, combined with other embolic agents or alone, in different abdominal diseases: a single-center experience in 30 patients

Background

Squid, as Onyx, is an ethylene-vinyl alcohol copolymer (EVOH)-based liquid embolic agent developed for neuroradiologic interventions with poor application in abdominal district. Our aim was to evaluate safety, complications, and efficacy of transcatheter embolization using the two available formulations Squid-18 and 12, in 30 patients affected by different abdominal diseases.

Results

Transcatheter embolization with Squid, combined with other embolic agents, as poly vinyl alcohol (PVA) particles, coils and amplatzer plugs, or alone (type 2 endoleak), was performed in 30 patients, as follows: 10 portal vein embolizations (PVEs), 6 arteriovenous malformations (AVMs), 5 visceral artery aneurysms (VAAs), 4 type 2 endoleaks, 3 preoperative embolizations, 1 acute arterial bleeding, 1 female varicocele. Squid was always administered using dimethyl sulfoxide (DMSO) compatible microcatheters. Technical success, 30-day clinical success and complications were assessed.

Technical success was 90%. 3 patients (2 AVMs, 1 VAA) required re-intervention successfully performed in all cases. Major complications, cases of microcatheter entrapment and DMSO-related poor pain control were not recorded. 30-day clinical success was 93.3%: in 2 patients submitted to PVE a sufficient future liver remnant (FLR) hypertrophy was not achieved.

Conclusion

Squid was successfully used with low complication rate in many abdominal diseases showing a valid embolic action either combined with other embolic agents or alone in type 2 endoleak. The availability of different formulations (Squid-18 and Squid-12) variable for viscosity makes Squid preferable to Onyx as EVOH-based liquid embolic agent, even though comparable studies in different abdominal districts with a larger cohort of patients will be necessary.