The incidence and fate of endoleaks vary between ruptured and elective endovascular abdominal aortic aneurysm repair

International multicenter experience on early and late outcomes after endovascular repair of ruptured abdominal aortic aneurysms in patients with vs without type II endoleaks

BACKGROUND

Ruptured abdominal aortic aneurysms (rAAAs) remain as a great clinical challenge for vascular surgeons and endovascular aortic repair (EVAR), which is currently regarded as the first-line treatment for rAAA in patients with appropriate anatomy. While recommendations for management of type II endoleaks (T2ELs) are well-established in the elective setting, data after rAAAs are limited.

METHODS

Between January 2018 and December 2022, all patients who were treated with EVAR for rAAA in three tertiary referral centers from different countries (Germany, Italy, and Switzerland) were screened for inclusion in the study. The patients were divided into two groups based on the presence or absence of early T2EL (at completion angiography or at first postoperative computed tomography angiography). The primary end points for this study were 30-day mortality and long-term survival.

RESULTS

Overall, 123 patients were included in the final analysis. Of these, 73 were categorized as not having an early T2EL (group A) and 50 presented an early T2EL (group B). Except for a significantly lower proportion of males in group A as compared with group B (79.5% vs 92%; P = .05), no significant baseline differences were found. At 30 days, the overall mortality rate was not significantly different between study groups (22% vs 16%; P = .16). Using binary regression, the presence of a T2EL was not associated independently with 30-day mortality (odds ratio, 1.712; 95% confidence interval, 0.591-3.964; P = .54). Five-year survival estimates in the whole study cohort did not show any significant difference in patients without a T2EL as compared to those with a T2EL (53% vs 59%; log-rank P = .31). Using Cox proportional hazard regression, the presence of T2ELs was not independently associated with increased risk for long-term mortality (hazard ratio. 1.068; 95% confidence interval, 0.437-2.611; P = .079).

CONCLUSIONS

Although the occurrence of a T2EL seems to be a relatively common scenario after EVAR for rAAA, their presence does not seem to be associated with worse outcomes in the immediate perioperative period or to decrease long-term survival. Therefore, careful observation may be warranted in the early phase, with selective treatment only in cases of ongoing hemodynamic decompensation. In the long run, it seems prudent to assume that the same indication for treatment as for standard EVAR could be recommended in the presence of T2EL.

Safety and Efficacy of Coil Embolization for Endoleak Prevention as an Adjunct to Endovascular Repair of Abdominal Aortic Aneurysm or Subsequently for the Repair of Endoleak

OBJECTIVE

This study assessed the real-world safety and efficacy of coil embolization during endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA) for prophylactic endoleak prevention or as a reintervention for endoleak repair, using the Cerenovus family of coils (Cerenovus, Irvine, CA, USA).

METHODS

This was a multicenter, retrospective cohort study of consecutive patients who underwent embolization of branching arteries during EVAR of an AAA or as a reintervention for endoleak repair, using Cerenovus coils between January 2017 and December 2021 in Japan. The primary outcome was 30-day reintervention-free survival, defined as cardiovascular mortality or any complication requiring reintervention within 30 days post procedure. Secondary outcomes included conversion to open surgical repair, length of hospitalization, and the following outcomes through 30 days and 1-year post procedure: occurrence of endoleak (Type I-V), reintervention, complications not requiring reintervention, aneurysm-related mortality, coil migration, and all-cause mortality.

RESULTS

A total of 306 patients (mean age 76.7 ± 7.8; 16.7% [51/306] female) were included in the study. Infrarenal AAA were most common (175/306; 57.2%), and the mean aneurysm size was 52.1 ± 10.9 mm. At 30 days, reintervention-free survival was achieved in 96.4% (295/306) of the patients; 9 (2.9%) patients required reintervention, and 2 (0.7%) died from cardiovascular causes through 30 days. One (1/305; 0.3%) patient underwent conversion to open repair. The mean length of hospitalization was 8.6 ± 7.2 days. Complications not requiring reintervention occurred in 3.9% (12/306) of the patients through 30-days and 12.4% (38/306) through 1-year. Endoleak occurred in 2.9% (9/306) of the patients at 30 days and 9.5% (29/306) at 1 year. Coil migration and aneurysm rupture were not reported for any patient. Aneurysm-related mortalities occurred in 0.0% (0/305) at 30 days and 0.3% (1/303) at 1 year. All-cause mortalities occurred in 0.7% (2/306) at 30 days and 3.3% (10/304) at 1 year.

CONCLUSIONS

This study demonstrated that the use of Cerenovus coils yielded a high rate of 30-day-reintervention-free survival and low rates of type II endoleak occurrence and recurrence at the target vessel through 30 days and 1 year in patients following EVAR of an AAA with coil embolization, either for prophylactic endoleak prevention during EVAR or as a reintervention to repair an endoleak.

An Expert-Based Review on the Relevance and Management of Type 2 Endoleaks Following Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

Ruptured abdominal aortic aneurysms (rAAAs) are life-threatening and require emergent surgical therapy. Endovascular aortic repair for rupture (rEVAR) has become the leading strategy due to its minimal invasive approach with expected lower morbidity and mortality, especially in patients presenting with hemodynamic instability and relevant comorbidities. Following rEVAR, intraoperative angiography or early postinterventional computed tomography angiography have to exclude early type 1 or 3 endoleaks requiring immediate reintervention. Persistent type 2 endoleaks (T2ELs) after rEVAR, in contrast to elective cases, can cause possibly lethal situations due to continuing extravascular blood loss through the remaining aortic aneurysm rupture site. Therefore, early identification of relevant persistent T2ELs associated with continuous bleeding and hemodynamic instability and immediate management is mandatory in the acute postoperative setting following rEVAR. Different techniques and concepts for the occlusion of T2ELs after rEVAR are available, and most of them are also used for relevant T2ELs after elective EVAR. In addition to various interventional embolization procedures for persistent T2ELs, some patients require open surgical occlusion of T2EL-feeding arteries, abdominal compartment decompression or direct surgical patch occlusion of the aneurysm rupture site after rEVAR. So far, in the acute situation of rAAAs, indications for preemptive or intraoperative T2EL embolization during rEVAR have not been established. In the long term, persistent T2ELs after rEVAR can lead to continuous aneurysm expansion with the possible development of secondary proximal type I endoleaks and an increased risk of re-rupture requiring regular follow-up and early consideration for reintervention. To date, only very few studies have investigated T2ELs after rEVAR or compared outcomes with those from elective EVAR regarding the special aspects of persisting T2ELs. This narrative review is intended to present the current knowledge on the incidence, natural history, relevance and strategies for T2EL management after rEVAR.

Midterm outcomes of physician-modified endovascular stent grafts for the treatment of complex abdominal aortic aneurysms in Korea: a retrospective study

Purpose

Physician-modified endovascular stent grafts (PMEG) are a good treatment option for complex abdominal aortic aneurysms (AAAs), especially in high-risk patients not amenable to open repair, and when commercial fenestrated devices are not available. We report our single-center experience with PMEG for the treatment of complex AAAs.

Methods

We retrospectively reviewed patients who underwent PMEG repair for AAA from November 2016 to September 2020 at our institution. Demographic data, anatomic characteristics, perioperative and postoperative outcomes, major adverse events, and 30-day mortality were analyzed.

Results

We identified 12 patients who underwent PMEG for complex AAA. The mean age was 74 years and the mean maximal AAA diameter was 58.1 mm. Indications for treatment included 4 impending or contained ruptures, 2 mycotic aneurysms, and 6 symptomatic cases. The technical success rate was 91.7%. Aneurysm sac regression was observed in 7 patients (58.3%), including 2 cases of complete regression. There was 1 aneurysm-related mortality at 3 months due to mycotic aneurysm. Also, there was 1 postoperative complication case of transient renal failure requiring temporary dialysis. At 1 year, there was 1 branch occlusion from the initial failed cannulation case and 2 type 1A endoleaks, and there was 1 case of open explantation.

Conclusion

PMEG showed a low technical failure rate and acceptable midterm stent durability and sac stability, comparable to conventional endovascular aneurysm repair. Despite the small number of cases, there was a tendency for a high sac regression rate, although longer follow-up is needed.

Treatment of Aortocaval Fistula Secondary to Abdominal Aortic Aneurysm: A Systematic Review

BACKGROUND

Aortocaval fistula (ACF) secondary to an abdominal aortic aneurysm is a rare complication, inadvertently caused by a rupture into the inferior vena cava. Different treatment modalities have been applied toward the repair of such lesions, including open surgical and endovascular repair. The aim of this study was to report on ACF treatment and to analyze its early and mid-term outcomes.

METHODS

A systematic search of the English medical literature published between 2000 and 2022 was undertaken, using PubMed, SCOPUS, and CENTRAL databases as per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 guidelines. A study protocol was registered in PROSPERO (CRD42022329058). Studies reporting on primary ACF outcomes following open surgical or endovascular repair were included. The ROBINS-I tool was applied for risk of bias assessment. Outcomes included technical success, 30-day and mid-term survival, endoleak following endovascular repair, and reintervention rates.

RESULTS

In total, 110 case studies, incorporating 196 patients (mean age; 66.2 years, males 96%) were included. Open surgical repair was applied in 78% (153/196). From the available data, technical success rate for each modality was 99% (152/153) and 100% (43/43), respectively. Open and endovascular repair demonstrated 87.5% (126/144) and 97.6% (42/43) 30-day survival, respectively, while mid-term survival was 86% (74/86) and 95.2% (20/21), respectively (medial follow-up: 14 months [1-54 months]). Endoleaks were reported in 19 endovascular cases (39.5%). Type II endoleak was the most frequent with a rate at 32.5% (14/43). Reintervention rates were 2.5% (4/151) and 35.7% (15/42) for open and endovascular repair, respectively.

CONCLUSIONS

Only few case studies were published on the treatment of this rare condition, while almost all invasive procedures were performed in males. Management of ACF repair with both open and endovascular approach was associated with excellent technical success rate and acceptable early and mid-term survival outcomes. Reintervention remained an issue for patients who were managed endovascularly.

Repair of Abdominal Aortic Aneurysms: JACC Focus Seminar, Part 1

Abdominal aortic aneurysms (AAAs), defined by an aortic diameter >3 cm, affect >1 million people in the United States. Risk factors for AAA include male sex, family history of AAA, smoking, Caucasian ethnicity, and age. Patients with known AAA should undergo regular surveillance via ultrasonography. Medical management, including smoking cessation and blood pressure management, is recommended for asymptomatic patients who do not meet the threshold for intervention. Repair options include endovascular aortic repair and open surgical repair, with good outcomes in long-term follow-up. Men with AAA >5.5 cm and women with AAA >5.0 cm in general should undergo elective repair. Medical management, including smoking cessation and blood pressure management, is recommended for asymptomatic patients who do not meet the threshold for intervention.

Relevance of Type II Endoleak After Endovascular Repair of Ruptured Abdominal Aortic Aneurysms: A Retrospective Single-Center Cohort Study

INTRODUCTION

Endovascular aortic repair (EVAR) is widely used as an alternative to open repair in elective and even in emergent cases of ruptured abdominal aortic aneurysm (rAAA). One of the most frequent complications after EVAR is type II endoleak (T2EL). In elective therapy, evidence-based therapeutic recommendations for T2EL are limited. Completely unclear is the role of T2EL after EVAR for rAAA (rEVAR). This study aims to investigate the significance of T2ELs after rEVAR.

PATIENTS AND METHODS

This is a retrospective single-center data analysis of all patients who underwent rEVAR between January 2010 and December 2020 with primary T2EL. The outcome criteria were overall and T2EL-related mortality and reintervention rate as well as development of aneurysm diameter over follow-up (FU).

RESULTS

During the study period between January 2010 and December 2020, 35 (25%) out of 138 patients with rEVAR presented a primary postoperative T2EL (age 74±11 years, 34 males). At rupture, mean aneurysm diameter was 73±12 mm. Follow-up was 26 (0-172) months. The reintervention-free survival was 69% (95% confidence interval [CI]: 55%-86%) at 30 days, 58% (95% CI: 43%-78%) at 1 year, and 52% (95% CI: 36%-75%) at 3 years. In 40% (n=14), T2ELs resolved spontaneously within a median time of 3.4 (0.03-85.6) months. The overall and T2EL reintervention rates were 43% (n=15) and 9% (n=3), respectively. Within 30 days, 11 patients (31%) required reintervention, of which 2 were T2EL related. Aneurysm sac growth by ≥5 mm was seen in 3 patients (9%), and aneurysm shrinkage rate was significantly higher in sealed T2EL group (86% vs 5%, p<0.0001). The overall survival was 85% (95% CI: 74%-98%) at 30 days, 75% (95% CI: 61%-92%) at 1 year, and 67% (95% CI: 51%-87%) at 3 years. Six deaths were aneurysm related, while 1 was T2EL related within the first 30 days due to persistent hemorrhage. During FU, one more patient died due to a T2EL-related secondary rupture (T2EL-related mortality, 5.7%, n=2). Multivariable analysis revealed that arterial hypertension was associated with an increased risk for reintervention (hazard ratio [HR]: 27.8, 95% CI: 1.48-521, p=0.026) and age was associated with an increased risk for mortality (HR 1.14, 95% CI: 1.04-1.26, p=0.005).

CONCLUSION

T2ELs after rEVAR showed a benign course in most cases. In the short term, the possibility of persistent bleeding should be considered. In the mid term, a consequent FU protocol is required to detect known late complications after EVAR at an early stage and to prevent secondary rupture and death.

[Endoleaks in endovacular treatment of infrareneral abdominal aortic aneurysm (part I)]

We analyzed the PubMed, Scopus databases and the eLIBRARY electronic library regarding appropriate literature data. In the first part, modern classifications of endoleaks type 1 and 2 after stenting of infrarenal aortic aneurysm are considered. We described causes, risk factors and effectiveness of various treatment options.

Computational analysis of endovascular aortic repair proximal seal zone preservation with endoanchors: A case study in cylindrical neck anatomy

BACKGROUND

Endovascular aortic repair is the common approach for abdominal aortic aneurysms, but endoleaks remain a significant problem with long-term success. Endoanchors have been found to reduce the incidence of type 1A endoleaks and can treat intraoperative type 1a endoleaks. However, little is known about the optimal number and position of endoanchors to achieve the best outcome.

METHODS

Using image segmentation and a computational model derived from a reconstructed native patient abdominal aortic aneurysm geometry, the stability of the proximal seal zone was examined through finite element analysis in Abaqus (Dassault Systèmes, Providence, RI). The biomechanical parameter of contact area was compared for varying numbers (0, 2, 4, 8) and positions (proximal, medial, distal) of endoanchors under different adhesion strengths and physiologic pressure conditions.

RESULTS

In every simulation, an increase in adhesion strength is associated with maintenance of proximal seal. For biologically plausible adhesion strengths, under conditions of normal blood pressure (120 mm Hg), the addition of any number of endoanchors increases the stability of the endograft-wall interface at the proximal seal zone by approximately 10% compared with no endoanchors. At hypertensive pressures (200 mm Hg), endoanchors increase the stability of the interface by 20% to 60% compared with no endoanchors. The positioning of endoanchors within the proximal seal zone has a greater effect at hypertensive pressures, with proximal positioning increasing stability by 15% compared with medial and distal positioning and 30% compared with no endoanchors.

CONCLUSIONS

Endoanchors improve fixation within the proximal seal zone particularly under conditions of high peak systolic pressure. Seal zone stabilization provides a mechanism through which endoanchor addition may translate into lower rates of type 1a endoleaks for patients.

Editor's Choice - A Comparison of Computed Tomography Angiography and Colour Duplex Ultrasound Surveillance Post Infrarenal Endovascular Aortic Aneurysm Repair: Financial Implications and Impact of Different International Surveillance Guidelines

OBJECTIVE

Use of colour duplex ultrasound (CDUS) and computed tomography angiography (CTA) for infrarenal endovascular aortic aneurysm repair (EVAR) surveillance differs in internationally published guidelines. This study aimed firstly to compare CDUS detection of significant sac abnormalities with CTA. Secondly, a sensitivity analysis was conducted to compare financial estimates of the, predominantly CDUS based, local and Society of Vascular Surgery (SVS) protocols, the risk stratified European Society of Vascular Surgery (ESVS) protocol, and the CTA based National Institute of Health and Care Excellence (NICE) protocol.

METHODS

Agreement between CDUS and CTA was assessed for detection of significant sac abnormalities. Surveillance protocols were extrapolated from published guidelines and applied to infrarenal EVAR patients active on local surveillance at a large, single centre. Surveillance intensity was dependent on presence of endoleak and subsequent risk of treatment failure in accordance with surveillance recommendations. Estimates for each surveillance protocol were inclusive of a range of published incidences of endoleak, contrast associated acute kidney injury (AKI), and excess hospital bed days, and estimated for a hypothetical five year surveillance period.

RESULTS

The kappa coefficient between CDUS and CTA for detecting sac abnormalities was 0.68. Maximum five year surveillance cost estimates for the 289 active EVAR patients were £272 359 for SVS, £230 708 for ESVS, £643 802 for NICE, and £266 777 for local protocols, or £1 270, £1 076, £3 003, and £1 244 per patient. Differences in endoleak incidence accounted for a 1.1 to 1.4 fold increase in costs. AKI incidence accounted for a 3.3 to 6.2 fold increase in costs.

CONCLUSION

A combined CTA and CDUS EVAR surveillance protocol, with CTA reserved for early seal assessment and confirmatory purposes, provides an economical approach without compromising detection of sac abnormalities. AKI, as opposed to direct imaging costs, accounted for the largest differences in surveillance cost estimates.

Systematic review of embolization of type I endoleaks using liquid embolic agents

OBJECTIVE

The long-term success of endovascular aneurysm repair (EVAR) is limited by complications, most importantly endoleaks. In case of (persistent) type I endoleak (T1EL), secondary intervention is indicated to prevent secondary aneurysm rupture. Different treatment options are suggested for T1ELs, such as endo anchors, (fenestrated) cuffs, embolization, or open conversion. Currently, the treatment of T1EL with liquid embolic agents is available; however, results are not yet addressed. This review presents the safety and efficacy of embolization with liquid embolic agents for treatment of T1ELs after EVAR.

METHODS

A systematic literature search was performed for all studies reporting the use of liquid embolic agents as monotherapy for treatment of T1ELs after EVAR. Patient numbers, technical success (successful delivery of liquid embolics in the T1EL) and clinical success (absence of aneurysm related death, endoleak recurrence or additional interventions during follow-up) were examined.

RESULTS

Of 1604 articles, 10 studies met the selection criteria, including 194 patients treated with liquid embolics; 73.2% of the patients were male with a median age of 71 years. The overall technical success was 97.9%. Clinical success was 87.6%. Because the median follow-up was only 13.0 months (range, 1-89 months), data on long-term success are almost absent. Four cases (2.1%) of secondary aneurysm rupture after embolization owing to endoleak recurrence were reported. All ruptures occurred in aneurysms exceeding initial treatment diameter of 70 mm.

CONCLUSIONS

Initial technical success after liquid embolization for T1EL is high, although long-term clinical success rates are lacking. Within this review, the risk of secondary rupture is comparable with untreated T1EL at 2% with a median follow-up of 13 months, regardless of the initial success of embolization. In general, no decrease in secondary aneurysm rupture after embolization of T1EL after EVAR is demonstrated, although the results of late embolization are debated.

The Polymer-Based Technology in the Endovascular Treatment of Abdominal Aortic Aneurysms

An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta that progressively grows until it ruptures. Treatment is typically recommended when the diameter is more than 5 cm. The EVAR (Endovascular aneurysm repair) is a minimally invasive procedure that involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. For years, stent grafts' essential design was based on metallic stent frames to support the fabric. More recently, a polymer-based technology has been proposed as an alternative method to seal AAA. This review underlines the two platforms that are based on a polymer technology: (1) the polymer-filled endobags, also known as Endovascular Aneurysm Sealing (EVAS) with Nellix stent graft; and (2) the O-ring EVAR polymer-based proximal neck sealing device, also known as an Ovation stent graft. Polymer characteristics for this particular aim, clinical applications, and durability results are hereby summarized and commented critically. The technique of inflating endobags filled with polymer to exclude the aneurysmal sac was not successful due to the lack of an adequate proximal fixation. The platform that used polymer to create a circumferential sealing of the aneurysmal neck has proven safe and effective.

Aneurysm Volumes After Endovascular Repair of Ruptured vs Intact Aortic Aneurysms: A Retrospective Observational Study

Purpose

To compare changes in abdominal aortic aneurysm (AAA) sac volume between endovascular aneurysm repairs (EVAR) performed for ruptured (rEVAR) vs intact (iEVAR) AAAs and to determine the impact of early volume shrinkage on future complications.

Materials and Methods

A retrospective analysis was performed of all patients undergoing standard infrarenal EVAR from 2002 to 2016 at a tertiary referral institution. Only patients with degenerative AAAs and with 30-day and 1-year computed tomography angiography (CTA) imaging were included. Early sac shrinkage was defined as a volume sac reduction >10% between the first (<30-day) and the 1-year CTA. The primary endpoint was to compare AAA sac volume changes between patients undergoing rEVAR (n=51; mean age 71.0±8.5 years; 46 men) vs iEVAR (n=393; mean age 72.3±7.5 years; 350 men). Results are reported as the mean difference with the interquartile range (IQR Q1, Q3). The secondary endpoint was freedom from aneurysm-related complications after 1 year as determined by regression analysis; the results are presented as the hazard ratio (HR) and 95% confidence interval (CI).

Results

At baseline, the rEVAR group had larger aneurysms (p<0.001) and shorter (p<0.001) and more angulated (p=0.028) necks. Aneurysm sac volume decreased more in the rEVAR group during the first year [−26.3% (IQR −38.8%, −12.5%)] vs the iEVAR group [−11.9% (IQR −27.5%, 0); p<0.001]. However, after the first year, the change in sac volume was similar between the groups [−3.8% (IQR −32.9%, 31.9%) for rEVAR and −1.5% (IQR −20.9%, 13.6%) for iEVAR, p=0.74]. Endoleak occurrence during follow-up was similar between the groups. In the overall population, patients with early sac shrinkage had a lower incidence of complications after the 1-year examination (adjusted HR 0.59, 95% CI 0.39 to 0.89, p=0.01).

Conclusion

EVAR patients treated for rupture have more pronounced aneurysm sac shrinkage compared with iEVAR patients during the first year after EVAR. Patients presenting with early shrinkage are less likely to encounter late complications. These parameters may be considered when tailoring surveillance protocols.

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.

Cost-effectiveness of contrast-enhanced ultrasound for the detection of endovascular aneurysm repair-related endoleaks requiring treatment

OBJECTIVE

Follow-up after endovascular aneurysm repair is necessary to detect potentially life-threatening complications such as endoleaks. Computed tomography angiography (CTA) or magnetic resonance angiography (MRA) is often used as standard of care for follow-up. Contrast-enhanced ultrasound (CEUS) has been shown to be a viable and fast real-time nonionizing imaging modality with equivalent diagnostic accuracy while also being superior to color Doppler ultrasound. The aim of this cost-utility analysis was to evaluate the cost-effectiveness of this imaging method in comparison to others for the evaluation of endoleaks requiring treatment.

METHODS

A decision model based on Markov simulations estimated lifetime costs and quality-adjusted life years (QALYs) associated with CTA, MRA, CEUS, and color Doppler ultrasound. Model input parameters were obtained from recent literature. The applied sensitivity and specificity values amounted to 90.5% and 100.0% for CTA, 96.0% and 100.0% for MRA, 94.0% and 95.0% for CEUS, and 82.0% and 93.0% for color Doppler ultrasound. Probabilistic and deterministic sensitivity analysis was performed to estimate uncertainty of model results. To evaluate cost-effectiveness, incremental cost-effectiveness ratios were reported as a measure representing the economic value of a strategy compared with an alternative. The willingness to pay was set to $100,000/QALY.

RESULTS

In the base-case scenario for a willingness to pay of $100,000 per QALY, CEUS was the most cost-effective of the four diagnostic strategies with estimated costs of $17,383 and effectiveness of 9.770 QALYs. CTA was estimated to result in lifetime costs of $17,679 with an expected effectiveness of 9.768 QALYs, whereas color Doppler ultrasound showed expected costs of $17,287 with 9.763 QALYs. Expected costs and effectiveness of MRA amounted to $17,945 and 9.771 QALYs each. Base-case estimates of the incremental cost-effectiveness ratios for CEUS vs color Doppler ultrasound equaled $14,173.52/QALY.

CONCLUSIONS

CEUS is a cost-effective imaging method for the evaluation of therapy-requiring endoleaks in endovascular aneurysm repair surveillance.

Evolving concepts and management of endoleaks after endovascular aneurysm repair: where do we stand in 2019?

In recent years, there has been tremendous progress in endovascular aneurysm repair (EVAR) techniques and devices. This process has seen a change in incidence, risk factors, and treatment of endoleaks as well as in follow-up protocols after EVAR. In particular, recent literature has highlighted new concepts in the evaluation and prevention/treatment of type I and II endoleak after standard EVAR. There is also recent evidence regarding new imaging protocols for follow-up after EVAR, which include magnetic resonance imaging and contrast-enhanced ultrasound. This comprehensive review aims to outline the most recent concepts on imaging follow-up, pathophysiology/risk factors, and management of endoleaks.

Techniques and future perspectives for the prevention and treatment of endoleaks after endovascular repair of abdominal aortic aneurysms

The presence of endoleaks remains one of the main drawbacks of endovascular repair of abdominal aortic aneurysms leading to the increase of the size of the aneurysmal sac and in most of the cases to repeated interventions. A variety of devices and percutaneous techniques have been developed so far to prevent and treat this phenomenon, including sealing of the aneurysmal sac, endovascular embolisation, and direct sac puncture. The aim of this review is to analyse the indications, the effectiveness, and the future perspectives for the prevention and treatment of endoleaks after endovascular repair of abdominal aortic aneurysms.

Systematic review and meta-analysis of the risk of bowel ischemia after ruptured abdominal aortic aneurysm repair

OBJECTIVE

Outcomes after repair of ruptured abdominal aortic aneurysm (RAAA) have improved in the last decade. It is unknown whether this has resulted in a reduction of postoperative bowel ischemia (BI). The primary objective was to determine BI prevalence after RAAA repair. Secondary objectives were to determine its major sequelae and differences between open repair (OR) and endovascular aneurysm repair (EVAR).

METHODS

This systematic review (PROSPERO CRD42017055920) followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. MEDLINE and Embase were searched for studies published from 2005 until 2018. The methodologic quality of observational studies was assessed with the Methodological Index for Non-Randomized Studies (MINORS) tool. The quality of the randomized controlled trials (RCTs) was assessed with the Cochrane Collaboration's tool for assessing risk of bias. BI prevalence and rates of BI as cause of death, reoperation, and bowel resection were estimated with meta-analyses with a random-effects model. Differences between OR and EVAR were estimated with pooled risk ratios with 95% confidence intervals (CIs). Changes over time were assessed with Spearman rank test (ρ). Publication bias was assessed with a funnel plot analysis.

RESULTS

A total of 101 studies with 52,670 patients were included; 72 studies were retrospective cohort studies, 14 studies were prospective cohort studies, 12 studies were retrospective administrative database studies, and 3 studies were RCTs. The overall methodologic quality of the RCTs was high, but that of observational studies was low. The pooled prevalence of BI ranged from of 0.08 (95% CI, 0.07-0.09) in database studies to 0.10 (95% CI, 0.08-0.12) in cohort studies. The risk of BI was higher after OR than after EVAR (risk ratio, 1.79; 95% CI, 1.25-2.57). The pooled rate of BI as cause of death was 0.04 (95% CI, 0.03-0.05), and that of BI as cause of reoperation and bowel resection ranged between 0.05 and 0.07. BI prevalence did not change over time (ρ, -0.01; P = .93). The funnel plot analysis was highly suggestive of publication bias.

CONCLUSIONS

The prevalence of clinically relevant BI after RAAA repair is approximately 10%. Approximately 5% of patients undergoing RAAA repair suffer from severe consequences of BI. BI is less prevalent after EVAR than after OR.

Early experiences of endovascular aneurysm repair for ruptured abdominal aortic aneurysms

Purpose

The use of endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysms (r-AAA) is steadily increasing. We report early experiences of EVAR for r-AAA performed in two tertiary referral centers in Korea.

Methods

We retrospectively reviewed r-AAA patients treated by EVAR from May 2013 to December 2017. An EVAR-first strategy for r-AAA was adopted whenever feasible. The demographic information, anatomic characteristics, operative details, postoperative complications with special attention to abdominal compartment syndrome (ACS), and 30-day mortality were collected and analyzed.

Results

We identified 13 patients who underwent EVAR for r-AAA. Mean age was 74.2 years and mean AAA size was 74.2 mm. Two patients underwent cardiopulmonary resuscitation at initial presentation. Bifurcated stent grafts were used in 12 out of 13 cases and physician-modified endografts with fenestrated/chimney techniques were performed in 2 cases with short neck. Successful stent graft deployment was achieved in all cases. Three patients were suspected of having ACS and 2 of them underwent laparotomy for decompression. The 30-day mortality was 7.7% (1 of 13), the only mortality being a patient that refused decompressive laparotomy for suspected ACS.

Conclusion

Despite the small numbers, the outcomes of EVAR for treatment of r-AAA were very promising, even in selected cases with unfavorable anatomy. These outcomes were achieved by a dedicated and well-trained team approach, and by use of high-end angiographic technology. Finally, ACS after EVAR is not uncommon, and requires a high index of suspicion as well as liberal use of decompressive surgery.