Treatment of Type II Endoleak Using Onyx With Long-Term Imaging Follow-Up

Clinical Application of n-Butyl-2- Cyanoacrylate (NBCA) in the Transarterial Embolization for Type I/II Endoleak During and After EVAR Surgery

BACKGROUND

Exploring the effectiveness and safety of n-butyl-2-cyanoacrylate (NBCA) in the transarterial embolization for common endoleak during and after endovascular repair of aortic aneurysm (EVAR).

METHODS

A total of 226 patients with abdominal aortic aneurysm (AAA) were treated with EVAR in 4 years from August 2019 to February 2023, including 46 patients with ruptured aneurysms (rAAA). 37 cases, 28 nonruptured AAA patients and 9 rAAA patients, developed endoleak during EVAR surgery and follow-up period and were then treated with NBCA for transarterial embolization. A follow-up was done for at least 6 months to observe its clinical efficacy and adverse reactions.

RESULTS

Among 37 cases of endoleak, there were 8 cases of primary type Ia endoleak and one case of primary right type Ib endoleak in the rAAA group, one case of primary type Ib endoleak, 2 cases of secondary type Ia endoleak, and 25 cases of postoperative type II endoleak in the nonruptured AAA group. Three patients with primary type Ia endoleak were treated with coil-assisted NBCA in the rAAA group, while the remaining 34 patients with type I and type II endoleaks were treated with NBCA alone. All transarterial embolization achieved technical success, and the endoleak disappeared. Postoperative hospitalization observation showed that 3 cases of patients in the rAAA group who experienced primary type Ia endoleak during emergency EVAR surgery died within 4 days after surgery due to hemorrhagic shock and multiple organ failure. Two patients experienced non-AAA-related deaths during the follow-up period.

CONCLUSIONS

Transarterial embolization with NBCA for the treatment of primary and secondary endoleak is a safe and effective method. It can achieve more dense embolization of the aneurysm sac and more complex endoleaks embolization. And, it showed a low recurrence rate of endoleak and the incidence of perioperative complications after surgery, which is worthy of clinical promotion and application. Even in emergency EVAR combined with primary type I endoleak treatment in rAAA patients, patients can still benefit.

Effectiveness of Intra-operative Contrast-Enhanced Ultrasound Assessment to Optimize Type II Endoleak Embolization

PURPOSE

To analyze the effectiveness of type II endoleaks (T2E) embolization using intra-operative contrast-enhanced ultrasound (CEUS).

METHODS

Consecutive patients treated for T2E underwent a standardized protocol with trans-arterial or trans-lumbar access, large volume embolization, onlay fusion, and intra-operative CEUS. Technical success was defined by exclusion of endoleak by CEUS.

RESULTS

Twenty-six patients (mean age 81 ± 11 years old; 89% male) were treated. The mean aneurysm sac enlargement was 11 ± 8 mm from T2E diagnosis. Embolization was performed using Onyx® 18 in all patients with adjunctive coils in 13 patients (50%). After the first embolization, CEUS documented residual T2E in 13 patients (50%). Ten patients (38%) had additional embolization, which successfully eradicated the T2E in seven of them. Technical success was 50% after the first embolization attempt and 77% after additional attempts guided by CEUS (P = 0.080). There was no mortality. Median imaging follow-up was 22 months. Among the 20 patients with no residual T2E on completion CEUS, 16 (80%) had sac stabilization and none required additional interventions for T2E. Of the six patients with residual T2Es on CEUS, three had sac stabilization (50%) and one required additional reintervention for T2E. There was one late aortic rupture at 56 months.

CONCLUSION

One in two patients treated by T2E embolization had residual endoleak on intra-operative CEUS after a first embolization attempt, decreasing to one in four patients after multiple attempts. A negative completion CEUS following embolization was associated with higher rates of sac stabilization and no need for additional T2E embolization.

Injectable Shear-Thinning Hydrogels with Sclerosing and Matrix Metalloproteinase Modulatory Properties for the Treatment of Vascular Malformations

Sac embolization of abdominal aortic aneurysms (AAAs) remains clinically limited by endoleak recurrences. These recurrences are correlated with recanalization due to the presence of endothelial lining and matrix metalloproteinases (MMPs)-mediated aneurysm progression. This study incorporated doxycycline (DOX), a well-known sclerosant and MMPs inhibitor, into a shear-thinning biomaterial (STB)-based vascular embolizing hydrogel. The addition of DOX was expected to improve embolizing efficacy while preventing endoleaks by inhibiting MMP activity and promoting endothelial removal. The results showed that STBs containing 4.5% w/w silicate nanoplatelet and 0.3% w/v of DOX were injectable and had a 2-fold increase in storage modulus compared to those without DOX. STB-DOX hydrogels also reduced clotting time by 33% compared to untreated blood. The burst release of DOX from the hydrogels showed sclerosing effects after 6 h in an ex vivo pig aorta model. Sustained release of DOX from hydrogels on endothelial cells showed MMP inhibition (ca. an order of magnitude larger than control groups) after 7 days. The hydrogels successfully occluded a patient-derived abdominal aneurysm model at physiological blood pressures and flow rates. The sclerosing and MMP inhibition characteristics in the engineered multifunctional STB-DOX hydrogels may provide promising opportunities for the efficient embolization of aneurysms in blood vessels.

Liquid Embolic Agents for Endovascular Embolization: A Review

Endovascular embolization (EE) has been used for the treatment of blood vessel abnormalities, including aneurysms, AVMs, tumors, etc. The aim of this process is to occlude the affected vessel using biocompatible embolic agents. Two types of embolic agents, solid and liquid, are used for endovascular embolization. Liquid embolic agents are usually injectable and delivered into the vascular malformation sites using a catheter guided by X-ray imaging (i.e., angiography). After injection, the liquid embolic agent transforms into a solid implant in situ based on a variety of mechanisms, including polymerization, precipitation, and cross-linking, through ionic or thermal process. Until now, several polymers have been designed successfully for the development of liquid embolic agents. Both natural and synthetic polymers have been used for this purpose. In this review, we discuss embolization procedures with liquid embolic agents in different clinical applications, as well as in pre-clinical research studies.

The Challenge of Endoleaks in Endovascular Aneurysm Repair (EVAR): A Review of Their Types and Management

An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta above 3 cm or 50% greater than the segment above. It is a dangerous condition accounting for a substantial number of deaths per year and increasing at an alarming rate. Various factors come into play in the development of AAAs, which this study has elaborated on, including smoking and old age, demographics, and comorbid conditions. Endovascular aneurysm repair (EVAR) is a newer treatment modality used for AAAs in which an endograft device is placed into the aorta, thereby creating a bypass tract from the aneurysm and generating flow mimicking that of the natural aorta. It is minimally invasive and associated with less postoperative mortality and reduced hospital stay. However, EVAR is also associated with significant postoperative complications, including endoleaks, which were reviewed in depth. Endoleaks are postprocedural leaks into the aneurysm sac that are usually identified immediately after graft placement and indicate treatment failure. They are of five subtypes, categorized according to their mechanism of development. The most common type is type II endoleaks, and the most dangerous is type I endoleaks. Each subtype has multiple management options with varying rates of success. Prompt identification along with appropriate treatment of endoleaks can lead to better postoperative outcomes and improved quality of life for patients.

Endovascular aneurysm repair offers a survival advantage and is cost-effective compared with conservative management in patients physiologically unfit for open repair

OBJECTIVE

The endovascular aneurysm repair-2 (EVAR-2) trial suggested that EVAR in patients unfit for open surgical repair (OSR) failed to provide a significant overall survival advantage compared with conservative management. The aim is to compare survival and cost-effectiveness in patients with poor cardiopulmonary exercise test (CPET) metrics who underwent EVAR or were managed conservatively.

METHODS

A prospective database of all CPETs (1435 patients) performed to assess preoperative fitness for abdominal aortic aneurysm repair was maintained. A total of 350 patients deemed unfit for OSR underwent EVAR or were managed conservatively. A 1:1 propensity-matched analysis incorporating age, gender, anaerobic threshold, and aneurysm size was used to compare survival. Cost-effectiveness analysis was based on the economic model for the National Institute for Health and Care Excellence clinical guideline on abdominal aortic aneurysm treatment.

RESULTS

Propensity matching produced 122 pairs of patients in the EVAR and conservative management groups. The median overall survival for the EVAR group was significantly longer than that for the conservative management group (84 vs 30 months, P < .001). One-, three-, and five-year mortality in the EVAR group was 7%, 40%, and 68%, respectively, compared with 25%, 68%, and 82% in the conservative management group, all P < .001. The increment cost-effectiveness ratio for EVAR was £8023 (US$11,644) per quality-adjusted life year gained compared with £430,602 (US$624,967) in the National Institute for Health and Care Excellence guideline, which is based on EVAR-2 results.

CONCLUSIONS

EVAR offers a survival advantage and is cost-effective in selected patients deemed unfit for OSR based on CPET compared with conservative management.

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.

Left internal mammary artery access for embolization of the left subclavian artery in a patient with type II endoleak after thoracic endovascular aortic repair for a ruptured right-sided aortic arch aneurysm

A 65-year-old woman had presented with a ruptured type B intramural hematoma associated with a right-sided aortic arch aneurysm, a large Kommerell diverticulum (KD) and an aberrant left subclavian artery (LSA). She underwent total aortic arch replacement with elephant trunk, thoracic endovascular aortic repair, and LSA ligation distal to the left vertebral artery. She subsequently developed a brisk type II endoleak into the KD via retrograde flow from the left vertebral artery. Percutaneous access of the left internal mammary artery with coil embolization of the proximal LSA and KD was performed. At 5 years, computed tomography angiogram showed complete thoracic aortic remodeling without an endoleak. The results from the present case have illustrated the novel use of the left internal mammary artery as an alternative access for LSA embolization in patients with type II endoleak and limited access options.

A systematic review of the current status of interventions for type II endoleak after EVAR for abdominal aortic aneurysms

OBJECTIVE

To study the mid- and long-term outcomes of type II endoleak treatment after EVAR and the technical aspects of different techniques to exclude endoleaks which different embolic agents.

METHODS

A systematic review was performed using the approach recommended by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for meta-analyses of interventional studies. The comprehensive search was conducted using the following database: MEDLINE, EMBASE, and the Cochrane Library. Patient characteristic, intervention approaches, embolic agents, and results at mid and long term follow up were studied.

RESULTS

A total of 6 studies corresponding to a total of 141 patients fulfilled the inclusion criteria with a mean age of 73-78.6 years and a mean duration of follow up varying from 25 to 42 months. There were different techniques for embolization used (translumbar, transarterial, and transcaval approach) with various types of embolic agents. In all studies, the indication for embolization of the type II endoleaks was sac enlargement of more than 5 mm. A wide range of technical success rate was reported regardless of the intervention strategy being used (17,6%-100%). The overall technical success rate of all studies was 62%.

CONCLUSION

This systematic review shows that there is a wide variety of techniques to exclude a persistent type II endoleak. Different kinds of embolic agents have be used. Due to a lack of peer reviewed data on longterm follow-up, it was not possible to come to recommendations what treatment would be the best for a durable exclusion of a persistent type II endoleak after an initially successful EVAR. There remains an urgent need for proper executed studies, either randomized or with close observation in relation to longer follow-up.

Chimney Graft Technique Combined With Embolization for Treating Ruptured Aortic Arch Lesions

Background: This study aimed to share the experience in applying the chimney graft technique combined with embolization for treating aortic arch rupture under emergency conditions and evaluating early-term results in these patients. Methods: This study retrospectively included patients with ruptured aortic arch lesions who received the chimney graft technique combined with embolization between March 2016 and March 2021. The primary endpoint was a technical success, deemed as successful stent graft deployment to the planned location, patency of the target branch vessel, and absence of significant type I endoleak. The secondary endpoint was clinical success defined with the size of false lumen in follow-up remaining unchanged or decreasing over time, 30-day mortality, complication, and primary patency of chimney graft. Results: This study included 12 patients (age, 61 ± 12 years; male, 83%). Five patients (42%) received single chimney, one patient (8%) received double chimney, and six patients (50%) received triple chimney. Intraoperative type I endoleak occurred in six patients (50%) who underwent endovascular embolization in the primary operation. Post-operative type I endoleak, evaluated by computed tomography angiography examination following the primary operation, occurred in seven patients (58%), including one patient who received endovascular embolization two times. All patients with post-operative type I endoleak were successfully re-treated using coil and Onyx glue within 1 week, and the median length of stay was 22 ± 11 days (range: 7-44 days). Overall technical success was 100%. Eleven patients had completed their follow-up (median, 12 months, range: 1-34 months), and one patient was out of contact. The 30-day mortality was 9% (1/11, post-operative death of a patient with cerebral hemorrhage). No major complications and no chimney compression, migration, occlusion, or stenosis were recorded during follow-up. Seven patients (58%) have ≥6 months of clinical follow-up time with appropriate imaging. In four (57%) of these patients, diameter stabilization was detected, whereas three (43%) experienced significant reduction (≥5 mm). Conclusion: The patients in this study had satisfactory early-term outcomes. The chimney graft technique combined with coil and Onyx glue embolization may be a safe and effective treatment for ruptured aortic arch lesions under emergency conditions.

Embolization of Type 2 Endoleaks in the Abdominal Aorta Using Ethylene Vinyl Alcohol Copolymer

BACKGROUND

 Type 2 endoleaks (T2EL) are the most frequent complication following endovascular aortic repair. Multiple studies primarily deal with the technical and clinical success of the embolization of persisting T2EL, thereby revealing controversial outcomes. Current reports rarely focus on the detailed execution of such a complex interventional procedure with respect to the difficult anatomic setting.

METHODS

 The present review provides an in-depth depiction and evaluation of the interventional methodology of the embolization of T2EL in the abdominal aorta with use of ethylene vinyl alcohol copolymer (EVOH). Complicating anatomic conditions are taken into account as well as technical and clinical success rates.

RESULTS

 Using the transarterial approach, there are at least 4 different pathways to access the nidus of a T2EL. CT-guided direct puncture of the aneurysm sac provides an alternative method of high technical success. EVOH with its slow solidification characteristics enables good control to achieve complete filling of the T2EL. During the intervention, however, it remains difficult to meet exactly the embolization endpoint, especially in large T2ELs.

CONCLUSION

 T2EL embolization using EVOH is an effective treatment with low major complication rates when conducted by skilled interventionists with detailed knowledge of diverse complex access routes.

KEY POINTS

  · Many roads lead to Rome to access the nidus of a T2EL including diverse complex transarterial pathways and direct aneurysm sac puncture.. · Ethylene vinyl alcohol co-polymer enables good control for slow filling of the nidus with low risk of major complications.. · Identification of the embolization endpoint remains difficult during the procedure and may result in secondary interventions.. · Successful T2EL embolization requires detailed knowledge of all access routes to the nidus and skilled handling of liquid embolics..

CITATION FORMAT

· Nolte-Ernsting C, Mecklenbeck F, Stehr A. Embolization of Type 2 Endoleaks in the Abdominal Aorta Using Ethylene Vinyl Alcohol Copolymer. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1502-7883.

Comparison of Cost and Efficacy of Trufill® vs Histoacryl® n-Butyl Cyanoacrylate for Translumbar Type 2 Endoleak Embolization

PURPOSE

The study aimed to compare the cost and efficacy of translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl® n-BCA liquid embolic.

METHOD AND MATERIALS

This was a retrospective review of patients who had translumbar approach type 2 endoleak repairs using either Trufill® or Histoacryl®. Patients were included if they underwent a technically successful type 2 endoleak repair via a translumbar approach with Trufill® or Histoacryl® n-BCA. A multivariable analysis was performed with the primary clinical outcome of percent change in aneurysm diameter per month compared. Procedure cost was calculated based on typical materials used.

RESULTS

20 Trufill® and 14 Histoacryl® patients were included. The mean procedure cost was higher for Trufill® ($5,757.30 vs. $1,586.09, p ≤ 0.001). There was no significant difference between Trufill® or Histoacryl® patients for age at first embolization, gender, total number of embolizations, number of feeding branches, aneurysm sac size prior to embolization, or residual endoleak at first follow-up. Trufill® patients had more coils used (12.0 vs. 4.3, p = 0.0007), less glue used (0.9 vs. 2.1 mL, p < 0.001), longer follow-up duration (33.5 vs. 13.2 months, p = 0.002), more follow-up CT angiograms (CTA) (3.7 vs. 1.9, p = 0.01), and larger excluded aneurysm sac size at most recent CTA (7.1 cm vs. 5.9 cm, p = 0.04). Percent change in sac diameter per month was not significantly different between Trufill® and Histoacryl® (0.21% vs. -0.25%/month, p = 0.06, respectively). There were no complications.

CONCLUSION

Use of Histoacryl® over Trufill® n-BCA resulted in significantly less procedural cost while maintaining safety and efficacy.

Type 2 Endoleak Management

Type 2 endoleaks are the most common endoleak type following endovascular aneurysm repair. The natural history of these endoleaks can vary, with some demonstrating a self-limited or indolent course, while others can contribute to aneurysm sac enlargement and rupture. A variety of embolization techniques, including transarterial catheterization and direct sac puncture techniques, have been developed for the treatment of type 2 endoleaks. In this article, the authors review the indications, techniques, and outcomes of current treatment strategies for type 2 endoleaks.

Single institutional experience of peripheral applications of a liquid embolic agent: Ethylene Vinyl Alcohol Copolymer

OBJECTIVE

To evaluate the safety and efficacy of ethylene vinyl alcohol (EVOH) copolymer for the treatment of a variety of peripheral vascular pathologies.

RESULTS

Between October 2010 and October 2017, 43 patients who underwent total 54 EVOH embolization procedures for the treatment of peripheral vascular pathologies were included. The cases which involved the use of EVOH for the treatment of nonvascular, neurologic, ophthalmologic, otolaryngologic or head-neck pathologies were excluded. The demographic data, technical and clinical success rates, and procedure-related details and complications were obtained. The most common indications for EVOH embolization were type II endoleaks (n = 18) and peripheral arteriovenous malformations (n = 14). The majority of cases (62.5%) used EVOH without any adjunct embolic material. The results of this study showed 100% technical success rates and 89% clinical success rates. No events of nontarget embolization or other procedure-related complications were noted. The mortality & morbidity rates were 0%. The loss to follow up rate was 16% (9 /54). The mean follow-up period was 134 days (range, 30 to 522 days).

CONCLUSION

The single institutional experience supports the safety and efficacy of EVOH embolization in the treatment of various peripheral vascular conditions.

Feasibility and Safety of Sac Embolization Using N-Butyl Cyanoacrylate in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysms or Isolated Iliac Artery Aneurysms

PURPOSE

To evaluate the feasibility and safety of sac embolization with N-butyl cyanoacrylate (NBCA) in emergency endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) in comparison to EVAR without sac embolization.

MATERIALS AND METHODS

Between February 2012 and December 2019, among 44 consecutive patients with ruptured AAA or IAA, 29 underwent EVAR. Of these, 22 patients (median age 77.5 years; 18 men) had concomitant sac embolization using NBCA; the remaining 7 patients (median age 88 years; 6 men) underwent EVAR without sac embolization and form the control group. The technical success, clinical success (hemodynamic stabilization), procedure-related complications, and mortality were compared between the groups.

RESULTS

All EVAR procedures and embolizations were successful. The clinical success rates in the NBCA and control groups were 95% (21/22) and 71% (5/7), respectively (p=0.14). There was no complication related to the procedure. Type II endoleak occurred in 4 of 21 patients (19%) in the NBCA group vs none of the control patients. One patient (5%) died in the NBCA group vs 3 (43%) in the controls (p=0.034).

CONCLUSION

Sac embolization using NBCA in emergency EVAR appears to be feasible and safe for ruptured AAA and IAA.

Migration of Ethylene Vinyl Alcohol Co-Polymer in the Urinary Tract Successfully Managed

Selective embolization is the treatment of choice for traumatic renal pseudoaneurysm. The use of ethylene vinyl alcohol copolymer (EVOH) was recently described as an embolic agent in peripheral lesions. The aim of a good embolic agent is to: achieve rapid and effective embolization; reach and fill distal vasculature targeted for embolization; be easy to prepare and use. Moreover, it should be highly radiopaque, controllable during administration, biocompatible and cost-effective. EVOH is a non-adhesive embolic agent and its efficacy is independent from the coagulant status. The risk of non-targeted embolization should be reduced by the good radio-opacity of the embolic material that is injected under continuous fluoroscopy. Nevertheless, symptomatic EVOH migration was described. We report a unique case of embolization of a renal pseudoaneurysm and migration of EVOH in the urinary tract. Retrograde trans-urethral removal of the migrated embolic agent was successfully performed. Our case report indicates that EVOH may not be appropriate when a fistula with renal calyx is suspected, even if its migration in the urinary tract may be managed.

Coil embolization of intercostal arteries accessed by surgical exposure for type II endoleak after thoracic endovascular aortic repair

Many patients with type II endoleak after thoracic endovascular aortic repair (TEVAR) are closely observed without secondary intervention. Herein, we report a new technique of coil embolization for type II endoleak from intercostal arteries after TEVAR for ruptured acute type B aortic dissection. A hybrid procedure of exposing intercostal arteries via subcostal incision in the prone position and transcatheter technique enables embolization of intercostal arteries at their origin from the aorta. This technique could avoid lung injury and be applicable in multiple intercostal arteries. This technique may be a useful secondary intervention for type II endoleak after TEVAR caused by intercostal arteries.

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.

Shear wave elasticity imaging for residual endoleak and thrombus characterisation after endoleak embolisation following endovascular aneurysm repair: a canine animal study

BACKGROUND

To evaluate residual endoleak and thrombus organisation with shear wave imaging (SWI) after endoleak embolisation through an animal study.

METHODS

This prospective experimental study involved eight dogs with creation of 16 iliac aneurysms and type I endoleak after endovascular aneurysm repair (EVAR). Embolisation agents were injected into the sac to seal endoleak. SWI and colour flow Doppler ultrasound (DUS) were performed at implantation, one week, and one and three months after implantation; for three dogs, SWI and DUS were also performed six months after implantation. Digital subtraction angiography and contrast-enhanced computed tomography were performed at sacrifice. Macroscopic and histopathological analyses were processed to identify regions of interest (ROIs) for endoleak, fresh thrombus, organised thrombus and embolisation agent, where SWI elasticity moduli were compared.

RESULTS

At sacrifice, nine aneurysms had residual endoleak, while seven were sealed. Ten had a fresh and 15 had an organised thrombus. SWI was able to detect all endoleaks, including two cases undetected with DUS. Elasticity moduli of 0.2 kPa ± 0.1 kPa (mean ± SD), 9.5 kPa ± 3.3 kPa, 48.1 kPa ± 21.3 kPa and 44.9 kPa ± 23.7 kPa were found in the ROIs positioned in endoleaks, fresh thrombi, organised thrombi and embolisation agent, respectively. Elasticity values of endoleak and fresh thrombus were lower than those of organised thrombi and embolisation agent (p < 0.001). Stiffness of fresh thrombus at one week (8.7 kPa ± 3.6 kPa) increased at three months (30.2 kPa ± 13.8 kPa), indicating thrombus maturation (p < 0.001).

CONCLUSIONS

In a dog model of iliac EVAR, SWI was able to identify endoleak, thrombus maturation and embolising agents after endoleak embolisation.

An Institution-Wide Algorithm for Treatment of Type II Endoleak Following Endovascular Aneurysm Repair (EVAR)

Objectives:

Multiple endovascular techniques have been described for the treatment of persistent type II endoleaks (pT2ELs) causing aneurysm sac growth following endovascular aneurysm repair (EVAR). In the event of a failed endovascular procedure and a pT2EL, a consensus regarding further treatment is lacking, and the literature suggests repeated endovascular attempts are rarely successful. Herein, we propose an algorithm for definitive management of pT2ELs with persistent sac growth following EVAR.

Methods:

A retrospective review of 29 patients who underwent treatment of persistent sac growth in the setting of pT2ELs was performed. Intervention methods were determined at the discretion of the operating surgeon. Aneurysmal sac enlargement was defined as a diameter increase > 5 mm, and persistent endoleak was defined as lasting greater than 6 months.

Results:

From 2000 to 2015, 917 EVAR procedures were performed at our institution. Isolated pT2ELs with sac enlargement were identified in 29 patients. Twenty-five patients underwent direct translumbar sac puncture and coiling and/or Onyx (Onyx, Plymouth, Minnesota) embolization of the culprit vessels. Thirteen (52%) of 25 patients had pT2EL after first endovascular intervention, and 10 (40%) of 25 patients failed 2 endovascular treatments. Of those 10, 7 displayed persistent aneurysmal sac growth and underwent a third embolization procedure. Type II endoleaks persisted in 6 patients; 3 patients were subsequently treated with laparotomy, ligation of lumbar vessels, sac exploration, and sac plication around the endograft. Technical success for this technique was 100%. During a mean follow-up of 38.4 months, no recurrent T2ELs, stent graft migration, and/or disjunction were observed.

Conclusions:

We propose a new algorithm for the management of pT2ELs. If 2 endovascular procedures fail to control of the endoleak, repeat endovascular attempts are not recommended. Endovascular failure should be followed by laparotomy with surgical ligation of culprit feeding vessels followed by sac exploration and plication of the sac, and endoaneurysmorrhaphy.

Improving the results of transarterial embolization of type 2 endoleaks with the embolic polymer Onyx

Introduction

Type 2 endoleaks (T2E) occur in 10 to 20% of patients after endovascular abdominal aortic aneurysm repair (EVAR) and remain a significant clinical issue.

Aim

To evaluate the efficacy and clinical outcomes of transarterial treatment of persistent type II endoleaks after EVAR using the liquid embolic Onyx.

Material and methods

From February 2012 to August 2015 transarterial T2E embolization was attempted in 22 patients (21 men, median age: 73, range: 62–88 years). Indications for treatment included an increase in the diameter of the aneurysm sac above 5 mm and a persistent endoleak observed for more than 6 months. Mean time from EVAR to endoleak treatment was 43 months (range: 2–125 months).

Results

Primary technical success was achieved in 17 (77.3%) patients and secondary technical success in 81.8%, with 0% in-hospital mortality. The mean procedure time was 95 ±48 min, with an average fluoroscopy time of 54 ±25 min. The mean amount of Onyx used was 7.5 ±6.6 ml. Clinical success was seen in 17/21 patients with follow-up imaging (80.9%). Mean follow-up time was 17 months (range: 3–38 months).

Conclusions

Onyx has been shown to effectively stabilize previous aneurysm growth as a result of the T2E in the majority of our patients. Transarterial embolization of T2E can be significantly improved as compared to previously reported results by using liquid embolic polymers such as Onyx.

Long-term results of intra-arterial onyx injection for type II endoleaks following endovascular aneurysm repair

Purpose

The aim of this paper is to report our experience of type II endoleak treatment after endovascular aneurysm repair with intra-arterial injection of the embolizing liquid material, Onyx liquid embolic system.

Methods

From 2005 to 2012, we performed a retrospective review of 600 patients, who underwent endovascular repair of an abdominal aortic aneurysm. During this period, 18 patients were treated with Onyx for type II endoleaks.

Principal findings

The source of the endoleak was the internal iliac artery in seven cases, inferior mesenteric artery in seven cases and lumbar arteries in four cases. Immediate technical success was achieved in all patients and no endoleak from the treated vessel recurred. During a mean follow-up of 19 months, no major morbidity or mortality occurred, and one-year survival was 100%.

Conclusions

Treatment of type II endoleaks with Onyx is safe and effective over a significant time period.

Embolization of Onyx Causing Acute Limb Ischemia

We present the case of a patient with a refractory type II endoleak treated with translumbar Onyx with passage of the Onyx material into the endograft and subsequent embolization to the infrainguinal vasculature. This report represents a new complication of Onyx embolization that, to our knowledge, has not previously been described in the literature.

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.

Defining risk and identifying predictors of mortality for open conversion after endovascular aortic aneurysm repair

OBJECTIVE

Risk of open conversion after endovascular aortic aneurysm repair (EVAR-c) is poorly defined. The purpose of this analysis was to determine outcomes of elective EVAR-c compared with elective primary open abdominal aortic aneurysm repair (PAR) in the Vascular Quality Initiative.

METHODS

Vascular Quality Initiative patients who underwent elective EVAR-c and PAR (2002-2014) were reviewed. Candidate predictors of major adverse cardiac event (MACE) and/or 30-day mortality were entered into a multivariable model, and stepwise elimination was used to reduce the number of covariates to a best subset of predictors. To estimate the additive risk of EVAR-c for MACE or 30-day mortality over PAR, this variable was added along with the best subset of predictors into generalized estimating equations logistic regression models.

RESULTS

We identified 159 EVAR-c and 3741 PAR patients. EVAR-c patients were older (73.5 ± 8.1 vs 69.5 ± 8.4 years; P < .0001), more likely to have diabetes (21% vs 15%; P = .03), and history of lower extremity bypass (9% vs 4%; P = .0006). EVAR-c was associated with a higher incidence of retroperitoneal aortic exposure (41%; n = 64 vs PAR, 26%, n = 976; P < .0001), use of a bifurcated graft (65%; n = 101 vs PAR, 52%; n = 1923; P = .001), greater blood loss (median [interquartile range], 2000 mL [1010-3500] vs PAR, 1200 mL [750-2000]; P < .0001) and longer procedure times (EVAR-c, 275 ± 122 minutes vs PAR, 232 ± 9 minutes; P < .0001). However, PAR more frequently was completed with a suprarenal and/or mesenteric cross-clamp (74%, n = 2749 vs EVAR-c, 53%, n = 83; P < .0001) and had a higher incidence of concomitant procedures (26%; n = 972 vs EVAR-c, 18%; n = 28; P = .03). Nonadjusted 30-day mortality was greater after EVAR-c: EVAR-c, 8% (n = 10) vs PAR, 3% (n = 105); P = .009. There was no difference in complication rates: EVAR-c, 33% (n = 52) vs PAR, 28% (n = 1056); P =.3. Preoperative 30-day mortality predictors included age (odds ratio [OR], 1.06/y, 95% confidence interval [CI], 1.04-1.1; P < .0001), chronic obstructive pulmonary disease (OR, 2.4; 95% CI, 1.6-3.5; P < .0001), history of leg bypass (OR, 2.3, 1.2-4.4;P =.01), suprarenal cross-clamp (OR 2.2, 1.2-4.1;P =.01), prior carotid revascularization (OR 2.2; 95% CI, 1.3-3.8; P = .0004), congestive heart failure (OR, 1.8; 95% CI, 0.9-3.5; P = .08), and female sex (OR, 1.6; 95% CI, 1.1-2.3; P = .02; area under the curve, 0.75). When controlling for covariates, EVAR-c was not significantly associated with MACE (OR, 1.2; 95% CI, 0.7-2.0; P = .4) or 30-day mortality (OR, 2.0; 0.9-4.2; P = .08).

CONCLUSIONS

EVAR-c patients are typically older, have more comorbidities, and experience greater blood loss and longer procedure times compared with PAR patients. However, postoperative morbidity and mortality are primarily driven by patient covariates and intraoperative factors, rather than the need for endograft explantation. Several preoperative variables were identified as predictors of 30-day mortality after elective EVAR-c and should be considered during the decision-making process for remedial treatment of failed endovascular PAR.

Management of Endoleaks

The management of endoleaks remains an inherent challenge to endovascular aneurysm repair (EVAR), particularly as evolving techniques and devices have allowed treatment of increasingly complex aneurysm anatomy. Endovascular techniques are the favored modality for endoleak repair and include techniques to bridge the endoleak defector and embolize the endoleak nidus and inflow/outflow vessels. Conversion to surgical repair remains the definitive option in cases where less invasive methods have failed or are precluded. In this article, the authors review evidence on the indications, approach, and outcomes of current techniques for endoleak management.

A Right Intercosto-Bronchial Artery Derived from the Thyrocervical Trunk: An Unusual Cause of Type II Endoleak Post Thoracic Aortic Stenting

The aetiology, incidence and management of type II endoleaks in standard infrarenal endovascular aortic aneurysm repair is well described. Far less data is available for thoracic stent grafting. We present a rare and interesting case of a type II endoleak post thoracic aortic stenting and highlight the aberrant anatomy that can cause this phenomenon in such cases.

Essentials of endovascular abdominal aortic aneurysm repair imaging: postprocedure surveillance and complications

OBJECTIVE

Lifelong postprocedural imaging surveillance is necessary after endovascular abdominal aortic aneurysm repair (EVAR) to assess for complications of endograft placement, as well as device failure and continued aneurysm growth. Refinement of the surveillance CT technique and development of ultrasound and MRI protocols are important to limit radiation exposure.

CONCLUSION

A comprehensive understanding of EVAR surveillance is necessary to identify life-threatening complications and to aid in secondary treatment planning.

Type 2 Endoleaks Post-EVAR: Current Evidence for Rupture Risk, Intervention and Outcomes of Treatment

Type 2 endoleaks (EL2) are the most commonly encountered endoleaks following EVAR. Despite two decades of experience, there remains considerable variation in the management of EL2 with controversies ranging from if to treat, when to treat and how to treat. Here, we summarise the available evidence, describe the treatment techniques available and offer guidelines for management.