Midterm outcomes of side branch embolization and endovascular abdominal aortic aneurysm repair

OBJECTIVE

To analyze the effects of total side branch embolization at endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms on the incidences of persistent type 2 endoleak (pT2EL), changes in sac diameter, and reintervention.

METHODS

Between 2013 and 2021, all patients who underwent primary EVAR with a few exceptions were included. Side branch embolization was considered during EVAR for inferior mesenteric artery (IMA) or IMA plus lumbar artery (LA) when feasible for contrast agent use. Outcomes measured were pT2EL, sac diameters, reintervention, ruptures, and aneurysm-related mortality. Radiation exposure and safety outcomes were also reported.

RESULTS

Among 732 patients who underwent EVAR, 616 (84.2%) were included. Of the 616 patients, 223 (36.2%) did not undergo side branch embolization (NO-E), whereas 228 (37.0%) underwent IMA only (IMA-E) and 165 (26.8%) underwent IMA+LA including median sacral artery (IMA+LA-E). The technical success rate of IMA and LA embolization was 97.0% and 74.7%, respectively. Crude incidences of pT2EL were significantly different from 6 months through 3 years (NO-E, 27.8%; IMA-E, 31.7%; IMA+LA-E, 9.4% at 3 years; P = .007). In the multivariate analysis adjusted for background differences, the incidences of pT2EL were significantly higher in the NO-E (odds ratio [OR], 3.21; 95% confidence intervals [CIs], 1.08-9.57; P = .004) and IMA-E (OR, 4.86; 95% CIs, 1.68-14.11; P = .004) compared with the IMA+LA-E group. Similarly, any reintervention until 3 years was significantly frequent in the NO-E (OR, 5.26; 95% CIs, 1.76-15.70; P = .003) and IMA-E group (OR, 4.19; 95% CIs, 1.38-12.67; P = .01). Surgical conversion and secondary rupture were seen only in 1 patient without any aneurysm-related mortality. Percent sac shrinkage from the baseline was significantly promoted in the IMA+LA group (NO-E, 12.1% ± 16.6%; IMA-E, 11.4% ± 16.7%; IMA+LA-E, 18.0% ± 18.8%; P = .047). Fluoroscopy time was significantly longer in the IMA+LA-E group (NO-E, 60.2 ± 47.4 minutes; IMA-E, 59.3 ± 39.5 minutes; IMA+LA-E, 75.5 ± 42.8 minutes; P < .0001), and so do the dose-area product (NO-E, 424.6 ± 333.4 Gy cm2; IMA-E, 477.7 ± 342.4 Gy cm2; IMA+LA-E, 631.8 ± 449.1 Gy cm2; P < .0001). No embolization-related complications or radiation-related adverse events were recorded.

CONCLUSIONS

Pre-emptive embolization of IMA, LAs, and median sacral artery at the time of EVAR reduced the incidences of pT2EL and any reintervention and promoted sac shrinkage during the follow-up period of 3 years.

Transcatheter arterial embolization of a type 2 endoleak through the dorsal pancreatic artery after the hybrid repair of a thoracoabdominal aortic aneurysm: A case report

An 83-year-old woman with a history of hybrid repair of thoracoabdominal aortic aneurysm presented with enlargement of the aneurysm due to a type 2 endoleak from the celiac artery. The endoleak cavity was accessed via the dorsal pancreatic artery, and embolization using N-butyl cyanoacrylate and coils was successfully performed. When celiac artery branches are embolized during hybrid repair of a thoracoabdominal aortic aneurysm, attention should be paid to the dorsal pancreatic artery to appropriately determine which branches are to be embolized, because a nonembolized dorsal pancreatic artery may lead to type 2 endoleaks.

Direct sac puncture versus transarterial embolization of type II endoleaks after endovascular abdominal aortic aneurysm repair: Comparison of outcomes

PURPOSE

Type 2 endoleak (T2EL) is the most common type of endoleak after endovascular abdominal aortic aneurysm repair (EVAR), and increases the risk of aneurysm sac rupture if it persists beyond 6 months. The purpose of this study is to compare the efficacy and safety of direct sac puncture versus transarterial embolization of T2ELs.

METHODS

Retrospective review of 42 consecutive T2EL embolization procedures, 19 by DSP and 23 by transarterial technique, between January 2015 and December 2020. Primary outcome was aneurysm sac stability and resolution of endoleak at follow-up imaging. Adverse events (AE) were classified based on the Society of Interventional Radiology (SIR) practice guidelines.

RESULTS

Technical success was 94.7% (18/19) in the DSP group and 86.9% (20/23) in the transarterial group (p = 0.32 (-0.77-0.25)). Treatment efficacy was evaluated in 16 patients in the DSP group and 18 patients in the transarterial group who had follow-up imaging ≥6 months after embolization. Mean imaging follow-up was 17.1 ± 11.2 (range, 6-41) months in the DSP group and 26.5 ± 15.4 (range, 6-48) months in the transarterial group (p = 0.06, -19.24-0.37). Treatment efficacy was 75% (12/16) in the DSP group and 33.3% (6/18) in the transarterial group (p = 0.02, 95% CI, 0.09-0.97). There was no procedure-related mortality. Moderate-severe AE occurred in 15.7% (3/19) in the DSP group and 8.7% (2/23) in the transarterial group (p = 0.44, -0.12-0.26).

CONCLUSION

In this study, DSP embolization of T2EL was equally safe and more effective than transarterial embolization in achieving aneurysm sac stability and resolution of endoleak.

Midterm Outcomes of Endovascular Abdominal Aortic Aneurysm Repair with Prevention of type 2 Endoleak by Intraoperative Aortic Side Branch Coil Embolization

OBJECTIVE

The midterm results of endovascular abdominal aortic aneurysm repair (EVAR) with aortic side branch coil embolization during EVAR was evaluated.

METHODS

Our center began coil embolization for all patent inferior mesenteric artery (IMA) and lumbar artery (LA) with an inner diameter more than 2.0 mm during EVAR since June 2015. When four or more LA were patent, coil embolization for LA with inner diameter 2.0 mm or less was done. EVAR without aortic side branches coil embolization was performed for 59 patients prior to June 2015 (control group) and 79 patients underwent EVAR with coil embolization during EVAR (coil group). The success rate of coil embolization for IMA and LA was evaluated in coil group. The frequency of type 2 endoleak (T2EL), freedom from aneurysm sac expansion (5 mm or more) rate and the rate of the aneurysm sac shrinkage (10 mm or more) were compared between the coil and control groups. Additionally, multiple logistic regression analysis for all patients was conducted to analyze whether IMA patency and the number of patent lumbar artery at the end of EVAR were the risk factors of the aneurysm sac expansion of 5 mm or more.

RESULTS

The success rate of IMA coil embolization was 96.4% and that of LA was 74.5%. Compared to the control group, the frequency of T2EL was significantly lower in coil group at 7 days (1.3% vs. 60.4%, P <0.0001) and at 6 months (2.1% vs 38.2%, P <0.0001) after EVAR. The freedom from aneurysm sac expansion rate was significantly better in the coil group at 5 years (100% in coil group and 65.2% in control group, P = 0.002). The rate of aneurysm sac shrinkage was significantly better in coil group (15.5% vs. 2.0% at 1 year, 42.8% vs. 6.3% at 2 years and 53.4% vs. 17.8% at 3 years, p = 0.0007). The risk of aneurysm sac expansion of 5 mm or more was estimated to be 11 times greater when the IMA was patent, and 4.9 times greater when 3 or more LAs were patent at the end of EVAR.

CONCLUSION

When IMA was occluded and the number of patent LA became 2 or less by aortic side branch coil embolization during EVAR, favorable mid-term results were safely obtained and good long-term result could be expected with EVAR.

Aortocaval fistula, a potentially favourable complication of abdominal aortic aneurysm rupture in endovascular repair

Endovascular aneurysm repair is an established treatment for ruptured abdominal aortic aneurysm. Primary aortocaval fistula is an exceedingly rare finding in ruptured abdominal aortic aneurysm, with a reported incidence of less than 1%. The presence of an aortocaval fistula used to be an unexpected finding in open surgical repair which often resulted in massive haemorrhage and caval injury. We present a case of ruptured abdominal aortic aneurysm with an aortocaval fistula that was successfully treated with percutaneous endovascular aneurysm repair under local anaesthesia. Despite a persistent type 2 endoleak the aneurysm sack shrank from 8.4cm to 4.8cm in 12 months. The presence of an aortocaval fistula may have depressurised the aneurysm, resulting in less bleeding retroperitoneally and may have promoted rapid shrinkage of the sac despite the presence of a persistent type 2 endoleak.

Atypical Type 2 Endoleak from an Artery Supplying the Psoas Major Muscle Following Endovascular Repair in a Case of Isolated Common Iliac Artery Aneurysm

In this report, we present a rare case of type 2 endoleak (T2EL) from an artery supplying the psoas major muscle, following an endovascular repair of a common iliac artery aneurysm (CIAA). A 79-year-old male underwent endovascular aneurysm repair (EVAR) for the right isolated CIAA using stent graft, with embolization of the ipsilateral internal iliac artery. The aneurysm was stable for 2 years, after which a follow-up CT revealed a 5 mm increase in the CIAA diameter and an endoleak of unknown origin. Conventional and CT angiographies revealed the source to be a branch from the ipsilateral deep circumflex iliac artery supplying the psoas major muscle that had developed an anastomosis at its terminal end with the vasa vasorum at the CIAA. Transarterial embolization of T2EL using glue was performed successfully, following which the T2EL disappeared.

A Novel Technique for the Treatment of Type 2 Endoleak After Endovascular Aortic Repair: Sac Embolization with Balloon Occlusion of the Aorta (SEBOA)

PURPOSE

We presented a new method of sac embolization using n-butyl-cyanoacrylate (NBCA) with balloon occlusion of the aorta (SEBOA) that can facilitate decreasing flow rate of the involved branches with the goal of type 2 endoleak resolution after endovascular aortic repair (EVAR).

TECHNIQUE

This technique is demonstrated in six patients who required type 2 endoleak treatment including previous technical failure. A transarterial approach was performed in four patients and transabdominal direct puncture in two. Technical success was defined as complete embolization of both involved branches and sac on postoperative CT. Sacography under balloon occlusion of the aorta demonstrated decreased flow rate of the all involved branches in all patients. SEBOA was performed using 25 or 33% of NBCA diluted with lipiodol. Technical success was obtained in 3 of 6 patients, and one major complication was observed with adhesion of NBCA to the microcatheter resulting in foreign body retention.

CONCLUSION

SEBOA may help solve the difficulty of type 2 endoleak treatment after EVAR as decreased flow rate of the involved branches under balloon occlusion of the aorta was achieved in all patients. However, protocols regarding concentration of NBCA or using other embolic materials are needed to improve the success rate.

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.

Perioperative factors associated with aneurysm sac size changes after endovascular aneurysm repair

PURPOSE

To identify the perioperative factors associated with aneurysm size changes after endovascular aortic aneurysm repair (EVAR).

METHODS

Between August, 2008 and December, 2014, 187 patients underwent EVAR treatment in our institution. The subjects of this study were 135 of these patients without peripheral artery disease, who were followed up with computed tomography (CT) for 3 years. Significant aneurysm size change was defined as sac size change of more than 5 mm from the baseline.

RESULTS

Sac enlargement was identified in 25 patients (18.5%) and sac shrinkage was identified in 59 (43.7%) patients. The factors associated with sac enlargement were postoperative pulse wave velocity (OR: odds ratio 3.80, p = 0.047), prevalence of a type 2 endoleak 1 week after surgery (OR 4.26, p = 0.022), inner diameter (OR 1.10, p = 0.005), and distance from the lower renal artery to the terminal aorta (OR 1.05, p = 0.017). The factors associated with sac shrinkage were prevalence of a type 2 endoleak (OR 0.09, p < 0.001) and preoperative pulse wave velocity (OR 0.32, p = 0.022). The factors independently associated with type 2 endoleak were the use of an Excluder device (OR 3.99, p = 0.002) and the length of the aneurysm (OR 1.02, p = 0.027).

CONCLUSION

Inner diameter, treatment length, perioperative pulse wave velocity, and type 2 endoleak were associated with sac size changes after EVAR.

Outcomes of type 2 endoleaks detected on venous phase CT arteriography

PURPOSE

The majority of type 2 endoleaks (T2EL) are identified on computed tomography angiography (CTA) both on arterial and venous phase. There is a subset of T2EL that are demonstrated only on venous phase CTA. This study was done to report the outcomes of T2EL detected only on venous phase CTA.

MATERIALS AND METHODS

A total of 261 consecutive T2EL treated via embolization were reviewed for the presence of endoleak demonstrated only on venous phase CTA. A group of 16 patients (12 men, 4 women; mean age, 80.1 years) was identified who had pre-embolization venous phase T2EL. Patients were evaluated for presence of T2EL after embolization, change in aneurysm diameter, and need for further intervention.

RESULTS

The prevalence of venous phase T2EL was 6.1% (16/261; 95%CI: 3.2%-9.0%). On post-embolization CTA, the rate of successful embolization at 6 months was 2/12 (17%; 95%CI: 0%-38%). At 6-month follow-up, mean change in aneurysm diameter was +2.3mm (n=12; 95%CI: -0.5mm to +5.0mm). In total, 4/16 (25%; 95%CI: 4%-46%) underwent re-embolization and 4/16 (25%, 95%CI: 4%-46%) underwent conversion to open repair. There was one aneurysm rupture, which was successfully treated surgically.

CONCLUSION

These results suggest that venous phase T2EL are not as responsive to embolization as standard T2EL and emphasize the need to follow patients with venous phase T2EL closely.

Rescue Therapy of Inadvertent Coil Migration for Endovascular Treatment of Type II Endoleak

Coil migration during endovascular procedures is not an unusual complication, but there is no standard management strategy for bailout. Here, we describe a technique for removal of a migrated coil using a snare. During embolization of type II endoleak from the inferior mesenteric artery in a post-endovascular aneurysm repair patient, the coil migrated to the sigmoidal artery causing an occlusion. We used a microsnare loop and successfully retrieved the migrated coil. This is the first case in Korea that uses a loop snare for the removal of a migrated coil during visceral endovascular treatment to our knowledge. This technique of using a microsnare for removal of displaced coils can be a good resort in selected cases.

Embolization for type 2 endoleak with sac expansion after endovascular repair of abdominal aortic aneurysm: safety and effectiveness

To evaluate the safety and outcome of embolization as treatment for persistent type 2 endoleak (T2EL) occurring after abdominal aortic stent graft implantation. This retrospective study included seven consecutive patients (one female, six males, mean age 72 years, range 66–88 years) with T2EL between January 2011 and September 2012. In all, T2EL was associated with an increase more than 5 mm in the aneurysm. The endoleak cavity or feeding artery was embolized with coils and/or n-butyl cyanoacrylate. Clinical success was defined as regression or stabilization of the aneurysm sac irrespective of residual endoleaks on follow-up CT studies. At the time of T2EL intervention, mean aneurysm sac diameter was 63 mm (range 52–72 mm), and mean increase size of aneurysm sac diameter was 7 mm (range 5–13). Mean follow-up period was 6.0 ± 6.2 months (range 3–18 months). Our technical success rate was 100 %. Clinical success was obtained in 5 (71.4 %) of the seven patients. One patient was embolized three times due to sac expansion. T2EL was treated by transarterial embolization in eight procedures, and one procedure was performed by direct puncture embolization. There were no major complications; two procedures elicited minor complications: transient back pain and muscle weakness of the left lower leg. We suggest embolization was safe and effective treatment, a less invasive treatment option comparison to open repair, as one choice to address T2EL.

Is intervention better than surveillance in patients with type 2 endoleak post-endovascular abdominal aortic aneurysm repair?

A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether, in patients with persistent type 2 endoleak (T2EL) post-endovascular abdominal aortic aneurysm repair (EVAR), intervention is associated with better outcomes than observation. Four hundred and eighty-three papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. In a recently published systematic review including 21 744 patients who underwent EVAR, 35.4% of T2ELs resolved spontaneously, 28.5% of secondary interventions were unsuccessful and rupture occurred in only 0.9% of patients with isolated T2EL. Spontaneous sealing in 62-75% of T2ELs were reported by two included studies. A failure rate of 80% associated with transarterial embolization in aggressive treatment of any T2EL was reported by one study. Conversely, another study reported a clinical success rate of 80% associated with the transarterial approach. One study reported that of patients who underwent embolization of a persistent T2EL, 37.9% continued to experience sac growth and 20% had recurrent endoleak at 5 years. One study demonstrated that the transealing procedure for T2EL had a technical success rate of 94.1%. We conclude that the available evidence with regard to management of persistent T2EL is mainly based on retrospective case series. Conflicting results from heterogeneous studies, however, failed to support an optimal threshold for intervention. Considering the reported relatively benign natural course of most T2ELs and the fact that most T2ELs seal spontaneously, conservative management of persistent T2EL in the absence of sac expansion might be appropriate. Where intervention is indicated, imaging should exclude occult type I and III leaks as ∼25% are not simple T2EL. Translumbar embolization of T2EL is associated with higher success rates than transarterial. Following a successful intervention, continued long-term surveillance is necessary due to the high risk (25-80%) of recurrence. The current evidence indicates that aneurysmal rupture due to an isolated T2EL is rare. Long-term prospective studies may provide better evidence to define the optimal threshold for intervention.