Endoleak Management following Endovascular Aneurysm Repair

Ultrasound Coded-Excitation Imaging for Endoleak Detection After Complex Endovascular Aortic Repair

OBJECTIVES

Several imaging modalities have been suggested for surveillance after fenestrated endovascular aortic repair in general and endoleak detection in specific. In the present project a coded excitation-based ultrasound (B-Flow) was investigated for endoleak detection after complex endovascular aortic repair.

METHODS

Patients post complex endovascular aortic repair (FEVAR or T/FEVAR) undergoing follow-up appointments including ultrasonography of the aorta at a vascular and endovascular surgery outpatient center were included in the study. B-Flow was compared with computed tomography angiography (CTA), Duplex ultrasound (DUS), and contrast-enhanced ultrasound (CEUS) regarding agreement and reliability for endoleak detection and characterization.

RESULTS

In total, 47 follow-ups were included. They accumulated in a total of 149 imaging investigations. Endoleaks were discovered in 44.7% of B-Flow studies and a majority of these endoleaks were classified as type II. Agreement between B-Flow and other imaging modalities was good (>80.0%) in general. However, with B-Flow 6 and 2 endoleaks would have been missed compared with CEUS and CTA, respectively. Regarding endoleak classification, B-Flow had a strong agreement (94.5%) with CEUS in detected cases. Furthermore, in a limited subset analysis, imaging findings were externally validated using findings from angiography.

CONCLUSIONS

Ultrasonography allows for endoleak detection and characterization without an invasive procedure or the use of potentially nephrotoxic contrast medium and can reduce radiation exposure. While CEUS mitigates issues of radiation and nephrotoxicity it still requires the intravenous application of contrast enhancers. Ultrasound coded-excitation imaging such as B-Flow could therefore further simplify endoleak surveillance after fenestrated endovascular aortic repair.

CIRSE Standards of Practice on Management of Endoleaks Following Endovascular Aneurysm Repair

BACKGROUND

Endoleaks represent the most common complication after EVAR. Some types are associated with ongoing risk of aneurysm rupture and necessitate long-term surveillance and secondary interventions.

PURPOSE

This document, as with all CIRSE Standards of Practice documents, will recommend a reasonable approach to best practices of managing endoleaks. This will include imaging diagnosis, surveillance, indications for intervention, endovascular treatments and their outcomes. Our purpose is to provide recommendations based on up-to-date evidence, updating the guidelines previously published on this topic in 2013.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of clinicians with internationally recognised expertise in endoleak management. The writing group reviewed the existing literature performing a pragmatic evidence search using PubMed to select publications in English and relating to human subjects up to 2023. The final recommendations were formulated through consensus.

RESULTS

Endoleaks may compromise durability of the aortic repair, and long-term imaging surveillance is necessary for early detection and correct classification to guide potential re-intervention. The majority of endoleaks that require treatment can be managed using endovascular techniques. This Standards of Practice document provides up-to-date recommendations for the safe management of endoleaks.

The impact of type 1a endoleak on the long-term outcome after EVAR

OBJECTIVE

Endoleaks remains a major determinant of outcome after endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysms. The objective of this study is to evaluate the long-term impact of proximal type 1 endoleak encountered at the case end of the EVAR procedure or during follow-up.

METHODS

All patients treated with EVAR between February 2001 and August 2017 in our institution were included. Data were collected retrospectively. A descriptive analysis of subgroups with type 1a endoleak at case end or with type 1a endoleak first encountered during follow-up was performed.

RESULTS

In total, 468 patients were included for analysis. At the case end of the EVAR procedure, in 5.3% (25/468) of patients, a type 1a endoleak was seen. In 72% of cases (18/25) the type 1a endoleak spontaneously disappeared on the first follow-up computed tomography angiography and never recurred. At the end of the follow-up period, no patient in this subgroup died with a type 1a endoleak on follow-up. In 3.4% (16/468) of all cases, a type 1a endoleak was encountered for the first time during follow-up. In 87.5% (14/16) of these cases, reintervention was performed. Two patients died with a persisting type 1a endoleak during follow-up.

CONCLUSIONS

Clinicians should differentiate between the type 1a endoleak at the case end and the type 1a endoleak first occurring during follow-up. For type 1a endoleak at the case end, expectant management can be adopted. Delayed type 1a endoleak seen during follow-up rarely seals spontaneously and needs reintervention in the majority of cases.

Short-Term Re-intervention of Endovascular Abdominal Aortic Aneurysm Repair

Background and aim

Endovascular aneurysm repair (EVAR) has revolutionized the management of abdominal aortic aneurysm (AAA). The re-intervention rate following EVAR has been a subject of debate in many studies. The study aims to evaluate the short-term outcomes in terms of the early (four-year) re-intervention rate following EVAR at our centre and compare it to the average re-intervention rate of the main studies assessed by the National Institute of Health and Care Excellence (NICE).

Methods

The EVAR procedures performed over two years (2015 and 2016) were retrieved using the operation codes. The clinical portal and PACS systems were used to review the discharge summaries, clinic and multidisciplinary team (MDT) letters, as well as the scans and interventional radiology procedures to assess the patients’ adherence to follow-up and identify any re-intervention procedure done to correct underlying problems related to the EVAR performed. Patients who switched their follow-up to another hospital were contacted and interviewed about any re-intervention undergone. 

Results

A total of 108 patients underwent EVAR during the two-year study period. Twenty EVAR-related re-interventions (18.5%) were recorded, irrespective of the cause or the type of intervention. This is slightly higher than the average rate by NICE (16.89%). Type 1 endoleak represented the leading cause for re-intervention (30%). Most of the cases of re-intervention were done endovascularly (60%). Forty-five percent of the patients had a re-intervention during the first year and 35% in the third year.

Conclusion

This study shows that although our re-intervention rate following EVAR was slightly higher than the international average, EVAR is still a safe method for the repair of AAA with relatively low peri-operative morbidity and mortality. However, long-term follow-up of these patients is mandatory as re-interventions are frequently required. Nonetheless, the majority of re-interventions can be done with minimal morbidity to the patient.

A novel approach for treating type II endoleaks utilizing contrast-enhanced ultrasound

Endoleaks are a frequent and well-known complication after endovascular repair of aortic aneurysms. An endoleak can lead to increased intrasac pressure, sac enlargement, and potential aneurysm rupture. Type II endoleaks result from retrograde filling of aortic branch vessels and can be treated with surgical, endovascular, or direct percutaneous approaches. Direct percutaneous treatment typically involves embolization of the perfused endoleak cavity typically using a translumbar approach with fluoroscopic guidance. We illustrate a novel image-guided approach for percutaneous transabdominal endoleak treatment using contrast-enhanced ultrasound in combination with fluoroscopy.

Sparse-sampling computed tomography for detection of endoleak after endovascular aortic repair (EVAR)

OBJECTIVES

To evaluate sparse sampling computed tomography (SpSCT) for detection of endoleak after endovascular aortic repair (EVAR) at different dose levels in terms of subjective image criteria and diagnostic accuracy.

METHODS

Twenty clinically indicated computed tomography aortic angiography (CTA) scans were used to obtain simulated low-dose scans with 100%, 50%, 25%, 12.5% and 6.25% of the applicated clinical dose, resulting in five dose levels (DL). From full sampling (FS) data sets, every second (2-SpSCT) or fourth (4-SpSCT) projection was used to generate simulated sparse sampling scans. All examinations were evaluated by four blinded radiologists regarding subjective image criteria and diagnostic performance.

RESULTS

Sensitivity was higher than 93% in 4-SpSCT at the 25% DL which is the same as with FS at full dose (100% DL). High accuracies and relative high AUC-values were obtained for 2- and 4-SpSCT down to the 12.5% DL, while for FS similar values were shown down to 25% DL only. Subjective image quality was significantly higher for 4-SpSCT compared to FS at each dose level. More than 90% of all cases were rated with a high or medium confidence for FS and 2-SpSCT at the 50% DL and for 4-SpSCT at the 25% DL. At DL 25% and 12.5%, more cases showed a high confidence using 2- and 4-SpSCT compared with FS.

CONCLUSIONS

Via SpSCT, a dose reduction down to a 25% dose level (mean effective dose of 1.49 mSv in the current study) for CTA is possible while maintaining high image quality and full diagnostic confidence.

Outcomes of translumbar embolization of type II endoleaks following endovascular abdominal aortic aneurysm repair

OBJECTIVE

Presence of an endoleak can compromise aneurysm exclusion after endovascular abdominal aortic aneurysm repair (EVAR). Type II endoleaks (T2Es) are most common and may cause sac expansion. We report outcomes of translumbar embolization (TLE) of T2Es following EVAR.

METHODS

We conducted a retrospective chart review of patients with T2E after EVAR treated with TLE from 2011 to 2018 at a single academic institution. Treatment indications were the presence of persistent T2E and aneurysm growth ≥5 mm. Sac stabilization was defined as growth ≤5 mm throughout the follow-up period.

RESULTS

Thirty consecutive patients were identified. The majority were men (n = 24), with a mean age of 74.3 years (95% confidence interval [CI], 70.9-77.6 years). The most common comorbidities were hypertension (83.3%) and coronary artery disease (54.0%). The mean maximal sac diameter at T2E discovery was 5.8 cm (95% CI, 5.4-6.2 cm). The mean time to intervention from endoleak discovery was 33.7 ± 28 months with a mean growth of 0.84 cm (95% CI, 0.48-1.2 cm) during that time period. The mean follow-up time after TLE was 19.1 months (95% CI, 11.1-27.2 months). Twenty-eight patients were treated with cyanoacrylate glue (CyG) alone, and two were treated with CyG plus coil embolization (CE). There was immediate complete endoleak resolution as assessed intraoperatively, and sac stabilization in 15 cases (50.0%). Eleven patients (36.7%) had evidence of persistent T2E on initial imaging after the embolization procedure; additional follow-up revealed eventual sac stabilization at a mean of 21.3 ± 7.2 months, and therefore, these patients did not require further intervention. In the remaining four cases (13.3%), there was persistent T2E after the initial TLE, requiring a second intervention. Repeat TLE stabilized growth in three of these four patients after a mean of 17.6 ± 12.9 months. One patient required open sacotomy and ligation of lumbar vessels due to continued persistence of the T2E and continued aneurysm growth. There were no ischemic complications related to the embolization procedures. Factors associated with persistent endoleak after initial embolization were larger aneurysm diameter at the time of initial endoleak identification (P < .001) and the use of antiplatelet agents (P < .02). The use of anticoagulation was not a significant risk factor for endoleak recurrence or aneurysm growth after TLE.

CONCLUSIONS

TLE of T2E is a safe and effective treatment option for T2E with aneurysm growth following EVAR. Patients taking antiplatelet medication and those with larger aneurysms at the time of endoleak identification appear to be at increased risk for persistent endoleak and need for subsequent procedures following initial TLE. These patients may require more intensive monitoring and follow-up.

The Fluid-Dynamics of Endo Vascular Aneurysm Sealing (EVAS) System failure

Purpose

The main objective of this work is to investigate hemodynamics phenomena occurring in EVAS (Endo Vascular Aneurysm Sealing), to understand if and how they could lead to type 1a endoleaks and following re-intervention. To this aim, methods based on computational fluid mechanics are implemented as a tool for checking the behavior of a specific EVAS configuration, starting from the post-operative conditions. Pressure and velocity fields are detailed and compared, for two configurations of the Nellix, one as attained after correct implantation and the other in pathological conditions, as a consequence of migration or dislocation of endobags.

Methods

The computational fluid dynamics (CFD) approach is used to simulate the behavior of blood within a segment of the aorta, before and after the abdominal bifurcation. The adopted procedure allows reconstructing the detailed vascular geometry from high-resolution computerized tomography (CT scan) and generating the mesh on which the equations of fluid mechanics are discretized and solved, in order to derive pressure and velocity field during heartbeats.

Results

The main results are obtained in terms of local velocity fields and wall pressures. Within the endobags, velocities are usually quite regular during the whole cardiac cycle for the post-implanted condition, whereas they are more irregular for the migrated case. The largest differences among the two cases are observed in the shape and location of the recirculation region in the rear part of the aorta and the region between the endobags, with the formation of a gap due to the migration of one or both of the two. In this gap, the pressure fields are highly different among the two conditions, showing pressure peaks and pressure gradients at least four times larger for the migrated case in comparison to the post-implanted condition.

Conclusions

In this paper, the migration of one or both endobags is supposed to be related to the existing differential pressures acting in the gap formed between the two, which could go on pushing the two branches one away from the other, thus causing aneurysm re-activation and endoleaks. Regions of flow recirculation and low-pressure drops are revealed only in case of endobag migration and in presence of an aneurysm. These regions are supposed to lead to possible plaque formation and atherosclerosis.

Endoleak and Pseudoaneurysm Formation in the Setting of Stent Graft Infection Following Endovascular Uretero-Arterial Fistula Repair: The Dreaded Complication

The complication of uretero-arterial fistula after prolong ureteral stenting is well recognized. The treatment is primarily endovascular stenting across the fistulous communication accepting the potential risk of stent graft infection. Herein we present a case of a 71-year-old female who developed an uretero-arterial fistula after prolong ureteral stenting and exchanges following ileal conduit obstruction. Initial treatment with left common iliac stenting controlled the hematuria, but only temporarily. Repeat angiography revealed a type 1b endoleak requiring stent extension. Unfortunately, persistent hematuria necessitating further angiography showed the development of a saccular pseudoaneurysm around the stent graft requiring proximal stent extension. A nuclear medicine indium 111-tagged white blood cell scan with single-photon emission CT (SPECT)/CT confirmed stent graft infection. Conservative therapy with antibiotics failed, causing graft failure that ultimately required bypass surgery.

Conservative management of type 1A endoleaks at completion angiogram in endovascular repair of infra-renal abdominal aortic aneurysms with current generation stent grafts

Purpose

Proximal type 1A endoleaks on completion intra-operative angiography are not infrequently seen following endovascular abdominal aneurysm repair (EVAR). The natural course of these leaks is not well established. We sought to determine the rate of spontaneous resolution and a conservative treatment approach to these endoleaks.

Methods

All cases involving endovascular repairs of infra-renal abdominal aortic aneurysms resulting in proximal type 1A endoleak on final intra-operative completion angiography were retrospectively reviewed from 1 April 2010 and 30 March 2015. Demographic, pre and post-procedural imaging, and clinical outcomes were reviewed. Summarizing descriptive statistics are reported.

Results

Of the 337 patients who underwent an EVAR, 24 patients (7.1%) had a proximal type 1A endoleak on final intra-operative angiography. Twenty-two of 24 patients (92%) with proximal type 1A endoleaks had spontaneous resolution on follow-up imaging without any intervention, while two (8%) patients had a persistent endoleak. One of these patients required intervention. The median follow-up for patients with resolved endoleaks was 2.5 years vs. 4 and 6 years, respectively, for patients that did not resolve spontaneously.

Conclusion

A conservative approach may be used in the management of patients with proximal type 1A endoleaks on completion angiography once maximum proximal seal was achieved intra-operatively as the vast majority of these leaks spontaneously seal.

Effectiveness of Embolization of Inferior Mesenteric Artery to Prevent Type II Endoleak Following Endovascular Aneurysm Repair: A Review of the Literature

Type II endoleak is a common complication that develops after endovascular aneurysm repair. Patients with type II endoleak, which has persisted for 6 months, have a significantly higher rate of aneurysmal sac enlargement, reintervention, and rupture. To date, several studies have examined the effectiveness of preoperative embolization of branch vessels for the prevention of type II endoleak. Particularly, the embolization of the large inferior mesenteric artery (IMA) seems to be a precise, safe, and effective method. IMA is a significant risk factor for type II endoleak. However, there is currently no strong evidence to prove which patients would benefit from preventive IMA embolization. In addition, considering the incidence of type II endoleak and the adverse event rate, routine embolization seems to be unreliable and time-consuming. Moreover, previous reports of preoperative IMA embolization were retrospective. Thus, prospective and randomized studies are necessary so that the usefulness of IMA embolization can be proved and the potential benefits can be assessed. To establish preventive IMA embolization as one of the effective therapeutic strategies to prevent type II endoleak and to maximize its therapeutic effect, we should provide a wide range of therapeutic strategies to suit the state of the patient.

Abdominal aortic aneurysms: pre- and post-procedural imaging

Abdominal aortic aneurysm (AAA) is a relatively common, potentially life-threatening disorder. Rupture of AAA is potentially catastrophic with high mortality. Intervention for AAA is indicated when the aneurysm reaches 5.0-5.5 cm or more, when symptomatic, or when increasing in size > 10 mm/year. AAA can be accurately assessed by cross-sectional imaging including computed tomography angiography and magnetic resonance angiography. Current options for intervention in AAA patients include open surgery and endovascular aneurysm repair (EVAR), with EVAR becoming more prevalent over time. Cross-sectional imaging plays a crucial role in AAA surveillance, pre-procedural assessment, and post-EVAR management. This paper will discuss the current role of imaging in the assessment of AAA patients prior to intervention, in evaluation of procedural complications, and in long-term follow-up of EVAR patients.

Complications and Reinterventions After Fenestrated and Branched EVAR in Patients with Paravisceral and Thoracoabdominal Aneurysms

The application of endovascular strategies to treat aneurysms involving the abdominal and thoracoabdominal aorta has evolved significantly since the inception of endovascular aneurysm repair. Advances in endograft technology and operator experience have enabled the management of a wider spectrum of challenging aortic anatomy. Fenestrated endovascular and branched endovascular aneurysm repair represent two technical innovations, which have expanded endovascular treatment options to include patients with paravisceral and thoracoabdominal aortic aneurysms. Although similar in many ways to standard aortic endografts, fenestrated and branched endografts have specific short- and long-term complications due to their unique modular endograft design and their sophisticated deployment mechanisms. This article aims to examine the commonly encountered complications with these devices and the endovascular reintervention strategies.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Unplanned stents in thoracic endovascular aortic repair for type B aortic dissection: A 16-year single-center report

Background

Unplanned stents in thoracic endovascular aortic repair mean additional stents implantation beyond the preoperative planning to achieve operation success. This study aimed to reveal the prevalence and consequences of unplanned stents in thoracic endovascular aortic repair for type B aortic dissection and explore the reasons, risk factors and solutions for unplanned stents.

Methods

Retrospectively analysis consecutive patients diagnosed as type B aortic dissection with initial tear originating distal from the left subclavian artery and underwent thoracic endovascular aortic repair from September 1998 to June 2014 in our center.

Results

Under the criteria, this study enrolled 322 patients, with 83 (25.8%) patients in unplanned group. The incidence rate of unplanned stents in thoracic endovascular aortic repair for type B aortic dissection in each year demonstrates as a bimodal curve. The curve showed that, 2003 and, 2004 was the first and highest peak and 2007 was the second peak. There was no difference in five-year survival rate between planned and unplanned patients (log-rank test, p = 0.994). The unplanned group had higher hospitalization expenses (142,699.08 ± 78,446.75 yuan vs. 175,238.58 ± 34,838.01 yuan; p = 0.019), longer operation time (104.50 ± 93.24 min vs. 179.08 ± 142.47 min; p < 0.001) and hospitalization time (17.07 ± 16.62 d vs. 24.00 ± 15.34 d; p = 0.001). The reasons for unplanned stents were type Ia endoleak (46 patients, 55.4%), bird beak (25 patients, 30.1%), and inappropriate shaping of stent (9 patients, 10.8%). Asymptomatic aortic dissection patients had higher incidence of unplanned stents. Short proximal neck length (2.66 ± 0.59 mm vs. 2.50 ± 0.51 mm; p = 0.016), short stent coverage length (154.62 ± 41.12 mm vs. 133.60 ± 44.33 mm; p = 0.002), and large distal stent oversize (75.44±10.77% vs. 82.68±15.80%; p <0.001) were risk factors for unplanned stents in thoracic endovascular aortic repair.

Conclusion

There are some special risk factors and reasons for unplanned stents in thoracic endovascular aortic repair for type B aortic dissection. Knowing these can we reduce the utilization of unplanned stents with appropriate methods.

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.

Ten-year single-centre experience with type II endoleaks: Intervention versus observation

Our objective was to determine the relative merits of intervention or observation of type II endoleaks (T2Ls). A retrospective analysis was performed on 386 infra-renal endovascular aneurysm repair (IR-EVAR) patients from 2006 to 2015. Annual surveillance imaging of patients undergoing EVAR at our centre were analysed, and all endoleaks were subjected to a multidisciplinary team meeting for consideration and treatment. In the 10-year time frame, 386 patients (79.5±8.7 years) underwent an IR-EVAR. Eighty-one patients (21.0%) developed a T2L and intervention was undertaken in 28 (34.6%): 17 (60.7%) were treated via a transarterial approach (TA) and 11 (39.3%) using the translumbar approach (TL). Fifty-three patients (65.4%) with T2Ls were managed conservatively. Patients who received T2L treatment had a greater proportion of recurrent T2Ls than patients who were conservatively managed ( p=0.032). T2Ls associated with aneurysmal growth were more resistant to treatment than those where there was no change or a decrease in aneurysm size during follow-up (0.033). There was no significant difference in the TA and TL approach with respect to endoleak repair success ( p=0.525). Treatment of a T2L did not confer a survival advantage compared to conservative management ( p=0.449) nor did the choice of either the TA or TL approach ( p=0.148). Our study suggests the development of a T2L associated with aneurysm growth may represent an aggressive phenotype that is resistant to treatment. However, this did not lead to an increased risk of mortality over follow-up. Neither a transarterial nor a translumbar approach to treating a T2L conferred superiority.

Delayed complication of abdominal aortic stent: a rare complication

We hereby present a case of recurrent abdominal aortic aneurysm due to endoleak to outline complications and secondary intervention strategies post endovascular aneurysm repair.

Management of acute limb ischemia after glue embolization of endoleak following endovascular abdominal aortic aneurysm repair

We describe the case of a 73-year-old woman who developed a type II endoleak and subsequent aneurysm sac expansion following endovascular abdominal aortic aneurysm repair. The endoleak was treated with a translumbar direct sac puncture and injection with n-butyl-2-cyanoacrylate. During the injection procedure, glue embolized distally, lodging into the right popliteal, proximal anterior tibial, and tibioperoneal arteries, causing acute limb ischemia that led to an emergency embolectomy. The patient recovered well, and the postoperative course was unremarkable. Acute limb ischemia secondary to glue embolization during endoleak management is rare, with potentially catastrophic complications that require urgent operative repair.

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.

Potential risk factors of re-intervention after endovascular repair for type B aortic dissections

OBJECTIVES

To assess the potential risk factors of re-intervention after thoracic endovascular aortic repair (TEVAR).

BACKGROUND

TEVAR has been chosen as a less invasive alternative for Type B aortic dissections (TBADs); however, the potential risk factors of re-intervention remain unclear.

METHODS

A total of 252 TBADs patients initially treated with TEVAR between September 1998 and July 2012 were retrospectively reviewed. The indications for the initial TEVAR were 32 aorta enlargement (24 chronic), 71 malperfusion, 46 rupture (32 chronic), 67 refractory pain (54 chronic), and 44 refractory hypertension (38 chronic). The patients were stratified into single-intervention group and multi-intervention group.

RESULTS

The mean age was 54.1 years with 81.7% of male. We found the time from symptom onset to TEVAR was longer in multi-intervention group (17 vs. 112.5 days, P = 0.006). Higher proportions of chronic dissection and smoking occurred in multi-intervention group (53.9% vs. 79.2% and 43.9% vs. 70.8%, P = 0.018 and 0.012, respectively). The differences of oversizing, operation time, contrast medium dose, and blood loss between the groups were significant (13.8 ± 2.4% vs. 16.4 ± 2.9%, 92.5 vs. 196 minutes, 110 vs. 210 ml, 100 vs. 300 ml; P < 0.001, <0.001, =0.002, and =0.003, respectively). The mortality within 30 days was 2.4% and the rates of stoke, paraplegia and retrograde dissection were 3.6%, 5.6% and 0.8%, respectively. The most common reasons of re-intervention were endoleaks, new dissections and incomplete thrombosis of the false lumen.

CONCLUSIONS

we concluded that chronic phase, smoking and too big oversizing were potential risk factors of re-intervention.

Changes in suprarenal and infrarenal aortic angles after endovascular aneurysm repair

Purpose

We investigated whether suprarenal and infrarenal aortic angles change after the endovascular aneurysm repair (EVAR) procedure and during follow-up, and investigated the correlation between infrarenal aortic angle after EVAR and type Ia endoleaks.

Methods

Data collected on 70 EVAR procedures for a fusiform infrarenal aortic aneurysm performed between May 2006 and December 2012 were supplemented with a retrospective review of charts and radiographs.

Results

The greater the preoperative infrarenal aortic angle, the greater the suprarenal aortic angle (r = 0.72, P < 0.001). The infrarenal aortic angle decreased after the EVAR procedure and continued to decrease slowly thereafter (all P < 0.001). Suprarenal aortic angle decreased immediately after the EVAR procedure and continued to decrease during the first month (P < 0.001). No differences in angulation were observed based on stent graft type. Type Ia endoleaks occurred with significantly greater incidence in patients with a larger post EVAR infrarenal angle (P = 0.037).

Conclusion

The infrarenal aortic angle decreased significantly immediately after the EVAR procedure and continued to decrease slowly thereafter. Suprarenal aortic angle decreased immediately after the EVAR procedure and continued to decrease during the first month. We found a correlation between infrarenal and suprarenal aortic angle. Type Ia endoleaks occurred with greater incidence in patients with a larger infrarenal angle immediately after EVAR.

Volumetric quantification of type II endoleaks: an indicator for aneurysm sac growth following endovascular abdominal aortic aneurysm repair

PURPOSE

To test the hypothesis that type II endoleak cavity volume (ECV) and endoleak cavity diameter (ECD) measurements are accurate indicators of aneurysm sac volume (ASV) enlargement in patients who undergo endovascular aneurysm repair (EVAR) in the abdominal aorta.

MATERIALS AND METHODS

The institutional review board approved and waived the need to obtain patient consent for this HIPAA-compliant retrospective study. In 72 patients who underwent EVAR, 160 computed tomographic (CT) angiography studies revealed type II endoleaks. Corresponding to these 160 CT angiography studies, 113 CT follow-up studies (in 52 patients) were available and were included in the analysis. ECV measurements were obtained by two observers in consensus by using arterial enhanced phase (ECVAEP) and 70-second delayed enhanced phase (ECVDEP) CT images. The ECVDEP was also normalized as the ECV/ASV ratio. Maximum (ECDM) and transverse (ECDT) ECDs were determined from delayed enhanced phase images. The outcome was determined as interval increase (>2%) in ASV versus stable or decreasing (≤2%) ASV. Receiver operating characteristic (ROC) analysis was used to compare the accuracy of type II ECV and ECD measurements in indicating interval increase in ASV.

RESULTS

In 56 (49.5%) of 113 CT studies in type II endoleaks, there was an interval increase in ASV. The accuracies of ECVDEP (area under the ROC curve [AUC], 0.85) and normalized ECVDEP (AUC, 0.86) were superior to the accuracies of ECDM (AUC, 0.73), ECDT (AUC, 0.73), and ECVAEP (AUC, 0.66). At ROC curve analysis, the sensitivity, specificity, and positive and negative predictive values for type II endoleak cavities with an ECVDEP of less than 0.5 mL for showing no future sac volume enlargement were 33% (19 of 57), 100% (56 of 56), 100% (19 of 19), and 60% (56 of 94), respectively.

CONCLUSION

With use of the delayed enhanced phase of CT angiography, ECV measurement is an accurate indicator of aneurysm sac enlargement.

Assessment of a new type I endoleak repair technique using an anchoring device

OBJECTIVE

Type I endoleaks are one of the most frequent and life-threatening complications of thoracic endovascular aortic repair. This study aimed to assess the use of suture-anchoring devices for repairing type I endoleaks.

METHODS

The descending aortic aneurysm model (saccular type) was made by side-to-end anastomosis to a Dacron graft. A Matsui-Kitamura stent graft was deployed to create a proximal type I endoleak. Approximately 5 mm above the upper rim of the anastomosis, the aorta was punctured by the pistol of the suture-anchoring device with a T-shaped bar under fluoroscopy. Sutures were applied until angiography showed the absence of a type I endoleak. During the process, two pressure measurements were used to perform continuous assessments of aortic pressure and intra-aneurysm sac pressure.

RESULTS

A mean ± SD of 5 ± 1 anchoring shots were used to eliminate type I endoleaks. The device performed well, and no complications were observed. The mean ± SD intrasac pressures before stent graft deployment, during endoleak maintenance, and after repair were 118 ± 5, 61 ± 4, and 26 ± 5 mm Hg, respectively. The postrepair pressure was significantly decreased (P < 0.001; Student t test).

CONCLUSIONS

Despite some anatomic and clinical limitations identified during the experiments, the effectiveness of the suture-anchoring device was confirmed. Further improvement of the device will soon lead to its use as a less invasive endoleak repair procedure.

Quality improvement guidelines for imaging detection and treatment of endoleaks following endovascular aneurysm repair (EVAR)

Major concerns after aortic aneurysm repair are caused by the presence of endoleaks, which are defined as persistent perigraft flow within the aortic aneurysm sac. Diagnosis of endoleaks can be performed with various imaging modalities, and indications for treatment are based on further subclassifications. Early detection and correct classification of endoleaks are crucial for planning patient management. The vast majority of endoleaks can be treated successfully by interventional means. Guidelines for Imaging Detection and Treatment of endoleaks are described in this article.

Evaluation and treatment of suspected type II endoleaks in patients with enlarging abdominal aortic aneurysms

PURPOSE

To evaluate angiographic diagnosis and embolotherapy of patients with enlarging abdominal aortic aneurysms and computed tomographic (CT) diagnosis of type II endoleak.

MATERIALS AND METHODS

A retrospective review was performed of all patients referred to a single vascular and interventional radiology section from January 1, 2003, to June 1, 2011, with a diagnosis of enlarging aneurysm and type II endoleak. Twenty-five patients underwent 40 procedures between 12 and 82 months after endograft insertion (mean, 48 mo) for diagnosis and/or treatment of endoleaks.

RESULTS

Type II endoleaks were treated with cyanoacrylate, coils, and ethylene vinyl alcohol copolymer in 16 patients. Technical success rate was 88% (14 of 16 patients) and clinical success rate was 100% (16 of 16 patients). Aneurysm growth was arrested in all cases over a mean follow-up of 27.5 months (range, 6-88 mo). Endoleaks in nine patients were misclassified on CT; two had type I endoleaks and seven had type III endoleaks. Four of the nine patients (two type I endoleaks and two type III endoleaks) were correctly classified after initial angiography. The other five type III endoleaks were correctly classified on CT after coil embolization of the inferior mesenteric artery. Direct embolization was performed via sac puncture with ethylene vinyl alcohol copolymer in two of the latter five patients and eliminated endoleaks in both.

CONCLUSIONS

Aneurysm growth caused by type II endoleaks was arrested by embolization. CT misclassification occurred relatively commonly; type III endoleaks purported to be type II endoleaks were found in 28% of patients (seven of 25).

Management of Endoleaks following Endovascular Aneurysm Repair

Endovascular aneurysm repair (EVAR) has emerged as a viable alternative to open repair for abdominal aortic aneurysms. Endoleaks are a complication unique to EVAR and can occur in up to 25% of patients. In this article, the management of endoleaks following EVAR will be discussed.

The burden of hard atherosclerotic plaques does not promote endoleak development after endovascular aortic aneurysm repair: a risk stratification

PURPOSE

To objectify the influence of the atherosclerotic burden in the proximal landing zone on the development of endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) or thoracic endovascular aneurysm repair (TEVAR) using objective aortic calcium scoring (ACS).

MATERIALS AND METHODS

This retrospective observation study included 267 patients who received an aortic endograft between 1997 and 2010 and for whom preoperative computed tomography (CT) was available to perform ACS using the CT-based V600 method. The mean follow-up period was 2 ± 2.3 years.

RESULTS

Type I endoleaks persisted in 45 patients (16.9%), type II in 34 (12.7%), type III in 8 (3%), and type IV or V in 3 patients, respectively (1.1% each). ACS in patients with type I endoleaks was not increased: 0.029 ± 0.061 ml compared with 0.075 ± 0.1349 ml in the rest of the patients, (p > 0.05; Whitney-Mann U-Test). There were significantly better results for the indication "traumatic aortic rupture" than for the other indications (p < 0.05). In multivariate logistic regression analyses, age was an independent risk factor for the development of type I endoleaks in the thoracic aorta (Wald 9.5; p = 0.002), whereas ACS score was an independent protective factor (Wald 6.9; p = 0.009). In the abdominal aorta, neither age nor ACS influenced the development of endoleaks.

CONCLUSION

Contrary to previous assumptions, TEVAR and EVAR can be carried out without increasing the risk of an endoleak of any type, even if there is a high atherosclerotic "hard-plaque" burden of the aorta. The results are significantly better for traumatic aortic.

Successful glue embolization of a late type 1A endoleak causing abdominal aortic aneurysm rupture

We describe the successful treatment with n-butyl cyanoacrylate embolization of a ruptured infrarenal abdominal aortic aneurysm caused by a late type-1A endoleak 10 years after endovascular aneurysm repair (EVAR).

Practice patterns for thoracic aneurysms in the stent graft era: health care system implications

BACKGROUND

The US Food and Drug Administration approved the first thoracic aneurysm endograft in 2005. However, because the United States lacks a thoracic aneurysm endovascular repair registry, implications of Food and Drug Administration endograft approval on surgical management of thoracic aneurysms in clinical practice are unknown.

METHODS

Retrospective review of thoracic aneurysm repair rates for 2000 to 2007 and analysis of patient characteristics and complications for 2006 and 2007 cohorts uses the National Inpatient Sample. International Classification of Diseases, 9th Revision codes were used to identify unruptured descending thoracic aneurysm cases undergoing either thoracic endovascular aortic repair (39.73) or open repair (38.45).

RESULTS

Thoracic aneurysm open repair averaged 3.3 per million from 2000 to 2002 and increased to 5.6 per million in 2003 with introduction of 16 slice computed tomographic scanners. In 2005 endovascular repair was 1.2 repairs per million, which increased dramatically to 6.1 repairs per million in 2006. In 2007, endovascular repair decreased to 4.8 repairs per million while the open repair rate was 3.1 repairs per million. The 2006 and 2007 open repair cohorts had more favorable baseline characteristics compared with the endovascular cohort. Open repair mortality was significantly greater than endovascular mortality in 2006 (estimated relative risk, 8.48; 95% confidence interval 3.03 to 23.75), but not in 2007 (estimated relative risk, 0.71; 95% confidence interval 0.12 to 4.24). Length of stay was greater for open repair in 2006 and 2007.

CONCLUSIONS

Thoracic endovascular aortic repair has been rapidly adopted in the United States resulting in increased treatment of thoracic aortic aneurysms. Despite older age and comorbidities, endovascular repair had better outcomes and shorter hospital stays.