Realistic expectations for patients with stent-graft treatment of abdominal aortic aneurysms. Results of a European multicentre registry

Contrast-Enhanced Ultrasound after Endovascular Aortic Repair: Supplement and Potential Substitute for CT in Early- and Long-Term Follow-Up

BACKGROUND

Endoleaks are the most common complication after endovascular aneurysm repair (EVAR). Computed tomography angiography (CTA) is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR.

METHODS

A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our center was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/magnetic resonance angiography and follow-up CEUS examinations. Last preinterventional CTAs before EVAR served as baselines with focus on potential cofactors such as age, body mass index, maximum aortic aneurysm diameters, endoleak orientation, and distance-to-surface influencing detection rates and classification.

RESULTS

In total, 101 patients were included in the analysis. Forty-four endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT.

CONCLUSIONS

CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on postinterventional assessment.

Perioperative Mortality and the Long-Term Outcome of Endovascular Abdominal Aneurysm Repair (EVAR): A Single-Centre Experience

Background Abdominal aortic aneurysm (AAA) is a dangerous disorder characterised by abnormal enlargement of the abdominal aorta. The severity of the aneurysm and the presence of symptoms determine the necessary monitoring or treatment to prevent potential fatalities. The objective of this study is to estimate the perioperative mortality and long-term outcome of endovascular abdominal aneurysm repair (EVAR). Patients and methods This is a descriptive, retrospective, observational study. We retrieved the data of the AAA patients who underwent EVAR at Glan Clwyd Hospital from January 2015 to January 2023. The study sample consisted of patients diagnosed with isolated AAA, with or without iliac branch involvement, who were deemed suitable for EVAR based on factors such as advanced age, presence of comorbidities, the complexity of the condition, history of prior surgery, fulfillment of indication criteria, and patient desire. The data was analysed using SPSS statistical software, version 21.0 (IBM Corp., Armonk, NY). Results Two hundred and twenty-two patients were studied. The outcome of the EVAR among the patients was endo-leak 28.4% (n = 63); migration 1.4% (n = 3); blockage 0.5% (n = 1); infolding 0.5% (n = 1); perioperative mortality 1.4% (3); and other complications like access site or acute kidney injury were 1.4% (n = 3). However, no complications were reported in most of the patients, 66.7% (n = 148). Upon evaluating the variables that could affect the outcome, we observed that the ASA grade, comorbidities, and the indication of the intervention had a significant effect on the outcome (P values = 0.000, 0.048, and 0.014, respectively). Conclusion The findings demonstrate that when EVAR is performed by a skilled team adhering to proper criteria, the results are optimal. The mortality rate during the perioperative period was 1.4%. Furthermore, we have shown a satisfactory rate of complications when compared to international data.

Outcomes of iliofemoral conduits during fenestrated-branched endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms

OBJECTIVE

To describe the technical pitfalls and outcomes of iliofemoral conduits during fenestrated-branched endovascular repair (FB-EVAR) of complex abdominal aortic aneurysms (CAAAs) and thoracoabdominal aortic aneurysms (TAAAs).

METHODS

We retrospectively reviewed the clinical data of 466 consecutive patients enrolled in a previous prospective nonrandomized study to investigate FB-EVAR for CAAAs/TAAAs (2013-2021). Iliofemoral conduits were performed through open surgical technique (temporary or permanent) in patients with patent internal iliac arteries or endovascular technique among those with occluded internal iliac arteries. End points were assessed in patients who had any iliac conduit or no conduits, and in patients who had conduits performed prior or during the index FB-EVAR, including procedural metrics, technical success, and major adverse events (MAE).

RESULTS

There were 138 CAAAs, 141 extent IV, and 187 extent I-III TAAAs treated by FB-EVAR with an average of 3.89 ± 0.52 vessels incorporated per patient. Any iliac conduit was required in 35 patients (7.5%), including 24 patients (10.4%) treated between 2013 and 2017 and 11 (4.7%) who had procedures between 2018 and 2021 (P = .019). Nineteen patients had permanent conduits using iliofemoral bypass, 11 had temporary iliac conduits, and 5 had endoconduits. Iliofemoral conduits were necessary in 12% of patients with extent I to III TAAA, in 6% with extent IV TAAA, and in 3% with CAAA (P = .009). The use of iliofemoral conduit was more frequent among women (74% vs 27%; P < .001) and in patients with chronic obstructive pulmonary disease (49% vs 28%; P = .013), peripheral artery disease (31% vs 15%; P = .009), and American Society of Anesthesiologists classification of III or higher (74% vs 51%; P = .009). There were no inadvertent iliac artery disruptions in the entire study. The 30-day mortality and MAE were 1% and 19%, respectively, for all patients. An iliofemoral conduit using retroperitoneal exposure during the index FB-EVAR was associated with longer operative time (322 ± 97 minutes vs 323 ± 110 minutes vs 215 ± 90 minutes; P < .001), higher estimated blood loss (425 ± 620 mL vs 580 ± 1050 mL vs 250 ± 400 mL; P < .001), and rate of red blood transfusion (92% vs 78% vs 32%; P < .001) and lower technical success (83% vs 87% vs 98%; P < .001), but no difference in intraoperative access complications and MAEs, compared with iliofemoral conduits without retroperitoneal exposure during the index FB-EVAR and control patients who had FB-EVAR without iliofemoral conduits, respectively. There were no differences in mortality or in other specific MAE among the three groups.

CONCLUSIONS

FB-EVAR with selective use of iliofemoral conduits was safe with low mortality and no occurrence of inadvertent iliac artery disruption or conversion. A staged approach is associated with shorter operating time, less blood loss, and lower transfusion requirements in the index procedure.

Artifacts in Contrast-Enhanced Ultrasound during Follow-up after Endovascular Aortic Repair: Impact on Endoleak Detection in Comparison with Computed Tomography Angiography

The study described here systematically analyzed how specific artifacts in contrast-enhanced ultrasound (CEUS) can affect the detection of endoleaks during follow-up after endovascular aortic repair (EVAR). Patients undergoing EVAR of atherosclerotic or mycotic abdominal aortic aneurysms using various standard and branched stent-graft material for visceral and iliac preservation were enrolled over 5 y and followed up with computed tomography angiography (CTA) and CEUS simultaneously. CEUS artifacts were frequently identified after EVAR procedures (59% of examinations) and were caused mainly by contrast agent, different prosthesis or embolization material and postinterventional changes in the aneurysm sac. This article describes how to identify important artifacts and how to avoid false-negative or false-positive interpretations of endoleaks. Despite artifacts, CEUS had higher sensitivity for endoleak detection after EVAR than CTA. CEUS was superior to CTA in the identification of late endoleaks type II and in follow-up examinations after embolization procedures, where beam-hardening artifacts limited CTA.

Endovascular Abdominal Aortic Aneurysm Repair

Most abdominal aortic aneurysms are treated with endovascular repair (EVAR) in current practice. EVAR has lower periprocedural mortality and morbidity than open surgical repair. Aneurysm neck morphology, iliac anatomy, and access vessel anatomy need careful assessment for the successful performance of EVAR. Regular and long-term follow-up with imaging is mandatory after EVAR, and patients who are less likely to comply are less favorable EVAR candidates. Endoleaks are the most frequent complication of EVAR. Most can be managed with transcatheter or endovascular means. Evolving technology and techniques are allowing more patients to be treated with EVAR with better long-term outcomes.

Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance.

DATA SOURCES

Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016.

METHODS

We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis.

RESULTS

We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups.

LIMITATIONS

Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data.

CONCLUSIONS

Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases.

FUTURE WORK

Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016036475.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Salvage of bilateral renal artery occlusion after endovascular aneurysm repair with open splenorenal bypass

We report renal salvage maneuvers after accidental bilateral renal artery coverage during endovascular aneurysm repair of an infrarenal abdominal aortic aneurysm. A 79-year-old man with an infrarenal abdominal aortic aneurysm was treated with endovascular aneurysm repair. Completion angiography demonstrated coverage of the renal arteries. Several revascularization techniques were attempted, including endograft repositioning and endovascular stenting through the femoral and brachial approach. The patient eventually underwent open splenorenal bypass with a Y Gore-Tex graft (W. L. Gore & Associates, Flagstaff, Ariz). After 3 months, computed tomography showed no evidence of endoleak and patent renal arteries. Renal function was well maintained, and the patient did not require dialysis.

Ultrasonography for endoleak detection after endoluminal abdominal aortic aneurysm repair

BACKGROUND

People with abdominal aortic aneurysm who receive endovascular aneurysm repair (EVAR) need lifetime surveillance to detect potential endoleaks. Endoleak is defined as persistent blood flow within the aneurysm sac following EVAR. Computed tomography (CT) angiography is considered the reference standard for endoleak surveillance. Colour duplex ultrasound (CDUS) and contrast-enhanced CDUS (CE-CDUS) are less invasive but considered less accurate than CT.

OBJECTIVES

To determine the diagnostic accuracy of colour duplex ultrasound (CDUS) and contrast-enhanced-colour duplex ultrasound (CE-CDUS) in terms of sensitivity and specificity for endoleak detection after endoluminal abdominal aortic aneurysm repair (EVAR).

SEARCH METHODS

We searched MEDLINE, Embase, LILACS, ISI Conference Proceedings, Zetoc, and trial registries in June 2016 without language restrictions and without use of filters to maximize sensitivity.

SELECTION CRITERIA

Any cross-sectional diagnostic study evaluating participants who received EVAR by both ultrasound (with or without contrast) and CT scan assessed at regular intervals.

DATA COLLECTION AND ANALYSIS

Two pairs of review authors independently extracted data and assessed quality of included studies using the QUADAS 1 tool. A third review author resolved discrepancies. The unit of analysis was number of participants for the primary analysis and number of scans performed for the secondary analysis. We carried out a meta-analysis to estimate sensitivity and specificity of CDUS or CE-CDUS using a bivariate model. We analysed each index test separately. As potential sources of heterogeneity, we explored year of publication, characteristics of included participants (age and gender), direction of the study (retrospective, prospective), country of origin, number of CDUS operators, and ultrasound manufacturer.

MAIN RESULTS

We identified 42 primary studies with 4220 participants. Twenty studies provided accuracy data based on the number of individual participants (seven of which provided data with and without the use of contrast). Sixteen of these studies evaluated the accuracy of CDUS. These studies were generally of moderate to low quality: only three studies fulfilled all the QUADAS items; in six (40%) of the studies, the delay between the tests was unclear or longer than four weeks; in eight (50%), the blinding of either the index test or the reference standard was not clearly reported or was not performed; and in two studies (12%), the interpretation of the reference standard was not clearly reported. Eleven studies evaluated the accuracy of CE-CDUS. These studies were of better quality than the CDUS studies: five (45%) studies fulfilled all the QUADAS items; four (36%) did not report clearly the blinding interpretation of the reference standard; and two (18%) did not clearly report the delay between the two tests.Based on the bivariate model, the summary estimates for CDUS were 0.82 (95% confidence interval (CI) 0.66 to 0.91) for sensitivity and 0.93 (95% CI 0.87 to 0.96) for specificity whereas for CE-CDUS the estimates were 0.94 (95% CI 0.85 to 0.98) for sensitivity and 0.95 (95% CI 0.90 to 0.98) for specificity. Regression analysis showed that CE-CDUS was superior to CDUS in terms of sensitivity (LR Chi² = 5.08, 1 degree of freedom (df); P = 0.0242 for model improvement).Seven studies provided estimates before and after administration of contrast. Sensitivity before contrast was 0.67 (95% CI 0.47 to 0.83) and after contrast was 0.97 (95% CI 0.92 to 0.99). The improvement in sensitivity with of contrast use was statistically significant (LR Chi² = 13.47, 1 df; P = 0.0002 for model improvement).Regression testing showed evidence of statistically significant effect bias related to year of publication and study quality within individual participants based CDUS studies. Sensitivity estimates were higher in the studies published before 2006 than the estimates obtained from studies published in 2006 or later (P < 0.001); and studies judged as low/unclear quality provided higher estimates in sensitivity. When regression testing was applied to the individual based CE-CDUS studies, none of the items, namely direction of the study design, quality, and age, were identified as a source of heterogeneity.Twenty-two studies provided accuracy data based on number of scans performed (of which four provided data with and without the use of contrast). Analysis of the studies that provided scan based data showed similar results. Summary estimates for CDUS (18 studies) showed 0.72 (95% CI 0.55 to 0.85) for sensitivity and 0.95 (95% CI 0.90 to 0.96) for specificity whereas summary estimates for CE-CDUS (eight studies) were 0.91 (95% CI 0.68 to 0.98) for sensitivity and 0.89 (95% CI 0.71 to 0.96) for specificity.

AUTHORS' CONCLUSIONS

This review demonstrates that both ultrasound modalities (with or without contrast) showed high specificity. For ruling in endoleaks, CE-CDUS appears superior to CDUS. In an endoleak surveillance programme CE-CDUS can be introduced as a routine diagnostic modality followed by CT scan only when the ultrasound is positive to establish the type of endoleak and the subsequent therapeutic management.

The pivotal role of matrix metalloproteinases in the development of human abdominal aortic aneurysms

Abdominal aortic aneurysms (AAAs) represent a chronic degenerative condition and impart the risk of a life-threatening episode of rupture. Chronic inflammation and destructive remodeling of the extracellular matrix of the aortic wall constitute trademarks of this entity. Multiple studies have implicated a group of locally produced matrix endopeptidases-the matrix metalloproteinases (MMPs)-as the main culprits of this process. For this reason, extensive research on the Identification of the role of these enzymes, as well as possible alternative pharmacological treatments of AAAs, has taken place during the last few years. The exact role of the several members of the group of metalloproteinases has already been discovered, and conservative therapeutic strategies oriented towards these agents have been suggested, but a Definite treatment plan is still a controversial topic. The possible role of a genetic predisposition to AAAs is another crucial topic that remains to be determined, as it would render the confrontation of this condition much more efficient.

Validation of the Simbionix PROcedure Rehearsal Studio sizing module: A comparison of software for endovascular aneurysm repair sizing and planning

An important determinant of successful endovascular aortic aneurysm repair is proper sizing of the dimensions of the aortic-iliac vessels. The goal of the present study was to determine the concurrent validity, a method for comparison of test scores, for EVAR sizing and planning of the recently introduced Simbionix PROcedure Rehearsal Studio (PRORS). Seven vascular specialists analyzed anonymized computed tomography angiography scans of 70 patients with an infrarenal aneurysm of the abdominal aorta, using three different sizing software packages Simbionix PRORS (Simbionix USA Corp., Cleveland, OH, USA), 3mensio (Pie Medical Imaging BV, Maastricht, The Netherlands), and TeraRecon (Aquarius, Foster City, CA, USA). The following measurements were included in the protocol: diameter 1 mm below the most distal main renal artery, diameter 15 mm below the lowest renal artery, maximum aneurysm diameter, and length from the most distal renal artery to the left iliac artery bifurcation. Averaged over the locations, the intraclass correlation coefficient is 0.83 for Simbionix versus 3mensio, 0.81 for Simbionix versus TeraRecon, and 0.86 for 3mensio versus TeraRecon. It can be concluded that the Simbionix sizing software is as precise as two other validated and commercially available software packages.

Endovascular AAA Repair: Prevention of Side Branch Endoleaks with Thrombogenic Sponge

Purpose:

To report a technique that might decrease the incidence of lumbar artery endoleaks following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs).

Methods:

Ninety-three patients (86 males, median age 72 years, range 56 to 88) undergoing EVR with the aortomonoiliac technique were entered into a study to detect and then occlude patent side branches before completion of the endografting procedure. Prior to deploying the iliac occluder, an aneurysmogram was performed to detect patent aortic side branches. If these side branches were found, an absorbable gelatin sponge was inserted into the aneurysm sac via the occluder introducer sheath. The patients were followed with contrast-enhanced spiral computed tomography (CT) at 1 week and 3, 6, and 12 months to detect the presence of endoleaks.

Results:

Forty-eight (52%) patients demonstrated patent side branches that were occluded by the insertion of gelatin sponges into the aneurysm sac. The remaining 45 patients without evidence of side branch flow were untreated. Ten (10.7%) patients died in the perioperative period, and 15 (16.1%) primary endoleaks (13 proximal, 2 distal) were detected. This left 68 (73.1%) patients for follow-up, 33 (48.5%) of whom had patent branch vessels treated with the thrombogenic sponge. The median follow-up was 4 months (range 1 to 17), during which time no side branch endoleak was detected on surveillance CT scans in any of the 68 patients, which included all patients treated with the thrombogenic sponge technique and those in whom no patent side branches had been identified.

Conclusions:

We have demonstrated a safe and reliable method of preventing lumbar artery endoleaks following endovascular AAA repair.

Treatment of post-liver transplant hepatic artery pseudoaneurysm with balloon angioplasty after failed stent graft placement

Hepatic artery pseudoaneurysm is a rare complication following liver transplantation but can lead to life threatening hemorrhage if not treated effectively and in a timely manner. We describe a hepatic artery pseudoaneurysm that occurred after liver transplantation in a 53-year-old woman. The pseudoaneurysm was initially treated by implantation of a balloon-expandable covered stent-graft, but an endoleak was observed 6 days later. The endoleak was successfully resolved by further balloon angioplasty, which expanded the cylindrical stent to a conical stent, matching the anatomy of the anastomotic hepatic artery. Follow-up ultrasound examinations demonstrated patent hepatic arteries, with no evidence of pseudoaneurysm. Balloon-expandable covered stent-graft may be utilized to treat hepatic artery pseudoaneurysm following liver transplantation, due to the remodeling ability of stent-grafts, enabling them to fit the diseased vessels.

[Imaging of endoleaks after endovascular aneurysm repair (EVAR) with contrast-enhanced ultrasound (CEUS)]

Endoleaks following endovascular aneurysm repair (EVAR) are common and present a diagnostic challenge in the follow-up after EVAR. Contrast-enhanced ultrasound (CEUS) is a promising new method for the diagnosis and follow-up of endoleaks. CEUS with SonoVue allows a rapid and non-invasive diagnosis in the follow-up after EVAR. The sensitivity and specificity of conventional ultrasound compared to the multislice CT angiography is estimated to be 33-63% and 63-93%, respectively. These values can be increased through the use of CEUS in up to 98-100% (sensitivity) and 82-93% (specificity). This article describes the etiology, classification and importance of different types of endoleaks. The value of CEUS in this clinical scenario will be discussed.

Multidetector-row computed tomography angiography in abdominal aortic aneurysm treated with endovascular repair: evaluation of optimal timing of delayed phase imaging for the detection of low-flow endoleaks

PURPOSE

To evaluate the optimal timing of delayed phase imaging for detecting low-flow endoleaks.

MATERIALS AND METHODS

Fifty-eight patients with unruptured abdominal aortic aneurysm treated with endovascular repair underwent 1- and 6-month follow-up multidetector row computed tomography (CT) performed during unenhanced, arterial, and delayed phase. At 6-month follow-up, delayed phase imaging, focused on stent graft, was performed with a delay of 60 (early delayed enhanced phase) and 300 seconds (late delayed enhanced phase) after intravenous injection of 120 mL of iodinated nonionic contrast medium (iomeprol 300 mgI/mL, Iomeron), at a flow rate of 3 mL/s via an antecubital vein, with a detector-row configuration of 4 x 1-mm, a 1.25-mm slice width, and a pitch of 6. Six-month follow-up CT images were independently evaluated by 2 readers during 2 different reading sessions: sets A (unenhanced, arterial, and early delayed phase images) and B (unenhanced, arterial, and late delayed phase images). Sensitivity and diagnostic accuracy of both reading sessions were compared. The standard of reference was represented by the combined evaluation of 1- and 6-month CT scans.

RESULTS

At standard of reference, 24 of 58 patients had an endoleak classified as type 1 in 2 cases, type 2 in 21 cases, and type 3 in the last 1 case. Seven of 21 type 2 endoleaks were classified as low-flow endoleaks. Set A reading session, including early delayed enhanced phase, allowed the detection of 19 of 24 endoleaks (5 false-negative cases represented by low-flow endoleaks), whereas all endoleaks were detected during set B reading session, including late delayed enhanced phase. Differences between sets A and B in terms of sensitivity and diagnostic accuracy were statistically significant (P < 0.05).

CONCLUSIONS

For optimal multidetector CT detection of low-flow endoleaks in patients who underwent endovascular repair, delayed phase should be acquired 300 seconds after injection of contrast medium.

The fate of infrarenal abdominal aortic aneurysms after stent grafting: influence of thrombosis at side branch ostia

PURPOSE

To evaluate the effect of postoperative thrombosis of the side branch ostia on the shrinkage of endoluminally treated abdominal aortic aneurysms with patent side branch vessels.

MATERIALS AND METHODS

Thirty-three patients were followed up with serial computed tomography (CT). Special attention was paid to presence or absence of retrograde enhancement of the side branch ostia after the covering of the patent side branch vessels by the stent graft and aneurysm diameter change on postoperative CT. Preoperative CT was also reviewed to assess the number of patent side branch vessels, degree of aneurysm wall calcification, and thickness of the mural thrombus. The patients with type 2 endoleak were excluded from this evaluation. The patients were divided into 2 groups, the nonthrombosed and thrombosed groups, based on presence or absence of retrograde enhancement of the side branch ostia as depicted on all postoperative CT.

RESULTS

Type 1 endoleak was not seen in all patients. Preoperative diameter of the aneurysm was 4.75 +/- 0.18 cm in the thrombosed group (n = 12) and 4.98 +/- 0.35 cm in the nonthrombosed group (n = 8). There were no significant differences in follow-up periods, preoperative diameter of the aneurysm, number of patent side branch vessels, degrees of aneurysm wall calcification, and thickness of the mural thrombus between the 2 groups. The mean diameter of the aneurysm in the nonthrombosed group did not change at 3 and 6 months then first decreased at 12 months after the stent grafting. However, in the thrombosed group, the mean diameter of the aneurysm had decreased at 3 months after stent grafting. Thereafter, the aneurysms continuously shrank.

CONCLUSIONS

Postoperative thrombosis of the side branch ostia may predict favorable shrinkage of endoluminally treated aneurysms.

Systematic Review and Meta-analysis of 12 Years of Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (ER) of abdominal aortic aneurysm (AAA) is a new technique, and reported rates of endoleak, conversion to open repair, rupture and mortality vary widely. The aim of this study was to estimate these rates from the published data, and examine how this has changed as more patients have undergone ER.

METHODS

A systematic review and meta-analysis of publications identified through searches of the electronic databases EMBASE and Medline. All publications quoting endoleak, conversion to open repair, rupture and mortality rates for a series of patients undergoing ER were included.

RESULTS

163 studies pertaining to 28,862 patients undergoing ER were identified as relevant for the review and meta-analysis. The pooled estimate for operative mortality was 3.3% (95% confidence interval 2.9 to 3.6%). The pooled estimate for type 1 endoleaks was 10.5% (95% confidence interval 9.0 to 12.1%), with an annual rate of 8.4% (95% confidence interval 5.7% to 12.2%). The pooled estimate of type 2,3 and 4 endoleaks was 13.7% (95% confidence interval 12.3 to 15.3%), with an annual rate of 10.2% (95% confidence interval 7.4% to 14.1%). The pooled estimate for primary conversion to open repair was 3.8% (95% confidence interval 3.2 to 4.4%), and for secondary conversion to open repair 3.4% (95% confidence interval 2.8 to 4.2%). The pooled estimate for post-operative rupture was 1.3% (95% confidence interval 1.1 to 1.7%), with an annual rupture rate of 0.6% (95% confidence interval 0.5% to 0.8%). Multivariate meta-regression analysis showed that rates of operative mortality, post-operative rupture and total number of endoleaks all fell significantly (p<0.05) over time.

CONCLUSIONS

This study demonstrates a low mortality and a gradual reduction in vascular morbidity and mortality associated with endovascular repair since it was first introduced.

Biomechanics of abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a condition whereby the terminal aorta permanently dilates to dangerous proportions, risking rupture. The biomechanics of AAA has been studied with great interest since aneurysm rupture is a mechanical failure of the degenerated aortic wall and is a significant cause of death in developed countries. In this review article, the importance of considering the biomechanics of AAA is discussed, and then the history and the state-of-the-art of this field is reviewed--including investigations into the biomechanical behavior of AAA tissues, modeling AAA wall stress and factors which influence it, and the potential clinical utility of these estimates in predicting AAA rupture.

Multidetector CT in Abdominal Aortic Aneurysm Treated with Endovascular Repair: Are Unenhanced and Delayed Phase Enhanced Images Effective for Endoleak Detection?

PURPOSE

To retrospectively determine the sensitivity and specificity of unenhanced, delayed enhanced phase (DEP), and arterial enhanced phase (AEP) multi-detector row computed tomography (CT) for depicting endoleaks during follow-up of endovascular aneurysm repair.

MATERIALS AND METHODS

Fifty patients (two women, 48 men; mean age, 72 years) underwent follow-up multi-detector row CT 1, 6, and 12 months after endovascular aneurysm repair. Unenhanced CT was performed with 2.5-mm collimation; 1-mm collimation was used with AEP and DEP examinations. Two independent readers assessed the presence of endoleak in three reading sessions: AEP (session A), unenhanced and AEP (session B), and AEP and DEP (session C). At 6- and 12-month follow-up, a fourth set was included: 1-month unenhanced and AEP (session D). Sensitivity, specificity, and positive predictive value of each session were calculated. Triple-phase multi-detector row CT was the reference standard.

RESULTS

At 1 month, sensitivity, specificity, and positive predictive value, respectively, were 79%, 75%, and 55% for session A; 93%, 97%, and 93% for session B; and 93%, 78%, and 62% for session C. At 6 months, sensitivity, specificity, and positive predictive value, respectively, were 92%, 68%, and 48% for session A; 92%, 100%, and 100% for session B; and 100%, 84%, and 67% for session C. At 12 months, sensitivity, specificity, and positive predictive value, respectively, were 80%, 80%, and 50% for session A; 90%, 98%, and 90% for session B; and 100%, 80%, and 56% for session C. Sensitivity did not significantly differ (P > .05) among reading sessions A, B, and C, whereas specificity and positive predictive values in session B were significantly higher (P < .001). For 6- and 12-month follow-up, no significant differences (P > .05) were found between sessions D and B.

CONCLUSION

The combination of AEP and unenhanced imaging performed at 1-month follow-up offers improved specificity and positive predictive values compared with AEP alone. DEP imaging does not significantly increase sensitivity for detection of endoleaks, but it does depict low-flow endoleaks not seen at AEP.

Technical and clinical success of infrarenal endovascular abdominal aortic aneurysm repair: A 10-year single-center experience

OBJECTIVE

The aim of our retrospective study was to review our single-center experience with aortic abdominal aneurysm (AAA) repair retrospectively.

MATERIAL AND METHODS

From 1995 to 2005, 70 consecutive patients affected by AAA were treated by endovascular stent-graft repair. Mean follow-up was 23.9 months. Follow-up investigations were performed at 6 and 12 months and yearly thereafter. Five different stent-graft designs were compared to each other. Primary technical success (PTS), assisted primary technical success (APTS), primary clinical success (PCS) and secondary clinical success (SCS) were evaluated.

RESULTS

All over PTS was achieved in 94.3%, APTS in 97.1%, PCS in 61.4%, APCS in 64.3% and SCS in 70%. There were 3 type I endoleaks, 25 type II endoleaks, 4 type III endoleaks, 8 limb problems, 5 conversions to open surgery, 10 aneurysm sac expansions and 14 device migrations. Patients with newer generation devices showed better results than patients with first generation prosthesis. In addition results were better for grafts with suprarenal fixation (versus infrarenal fixation) and grafts with barbs and hooks (versus grafts without barbs and hooks). Patients with bad anatomic preconditions showed a higher complication rate.

CONCLUSION

Contrary to first generation products, new stent-graft designs show acceptable technical and clinical results in endovascular AAA aneurysm repair. However, this therapy still should be reserved only for patients with significant comorbities and suitable anatomic conditions.

Diagnostic Value of Color Duplex Ultrasonography in the Follow-up of Endovascular Repair of Abdominal Aortic Aneurysma

PURPOSE

To systematically review the findings of diagnostic value of color duplex ultrasound (US) in the follow-up of endovascular repair of abdominal aortic aneurysms (AAAs).

MATERIALS AND METHODS

A search of PubMed and Medline databases for English-language literature was performed to find studies published between 1991 and 2005. Studies comparing the diagnostic accuracy of color duplex US with that of computed tomographic (CT) angiography were included, and analysis was performed of the detection of endoleaks and measurement of aneurysm diameter.

RESULTS

Twenty-one studies (39 separate comparisons) met the criteria and were included for analysis. Pooled estimates of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of color duplex US compared with CT angiography (with 95% CIs) were 66% (52%-81%), 93% (89%-97%), 76% (65%-87%), 90% (86%-95%), and 91% (86%-97%), respectively, for unenhanced color duplex US; and 81% (52%-100%), 82% (68%-97%), 58% (26%-90%), 95% (87%-100%), and 98% (91%-100%), respectively, for enhanced color duplex US. The sensitivity in the detection of endoleak was significantly improved with contrast material-enhanced color duplex US compared with unenhanced color duplex US (P < .05); however, no significant difference was found regarding the specificity, PPV, NPV, and accuracy between unenhanced and enhanced color duplex US (P > .05). Color duplex US was insensitive in measurement of aneurysm diameter compared with CT angiography in most situations.

CONCLUSIONS

Color duplex US is not as accurate as CT angiography and cannot replace CT angiography in the follow-up of endovascular aortic repair of AAAs. However, the use of contrast material-enhanced color duplex US resulted in improvement of diagnostic accuracy in the detection of endoleak and warrants further study.

Endoleakage after endovascular treatment of abdominal aortic aneurysms: diagnosis, significance and treatment

Endoleak, also called leakage, leak and Perigraft leak, is a major complication and its persistence represents a failure of endovascular aortic aneurysm repair. Its detection and treatment is therefore of primary importance, since endoleak can be associated with pressurization (increase in pressure) of the sac, resulting in expansion and rupture of the aneurysm. The aim of this paper is to discuss the definition, significance, diagnosis and different options to treat endoleak.

Long-term outcome after Talent endograft implantation for aneurysms of the abdominal aorta: A multicenter retrospective study

BACKGROUND

The development of newer-generation endografts for the endovascular treatment of abdominal aortic aneurysms has resulted in considerable improvements in clinical performance. However, long-term outcome data are still scarce. To assess long-term clinical and radiographic outcomes after use of the Talent stent graft, a retrospective analysis was performed that was based on 165 patients treated with this endograft in Germany between October 1996 and December 1998.

METHODS

Data were collected according to the recommendation of the ad hoc committee for standardized reporting practices in vascular surgery and were evaluated statistically by using univariate and multivariate analyses.

RESULTS

A total of 165 patients were treated with a Talent endograft in 9 German centers before December 31, 1998. Most were asymptomatic (94.5%), male (97.6%), and treated with a bifurcated graft (86.7%). Two patients (1.2%) died within 30 days, and 28 (17%) died during the follow-up period. The cause of death was aneurysm rupture in one case. Survival was 95.4% +/- 1.7% at 1 year, 89% +/- 2.6% at 2 years, 78.1% +/- 3.6% at 5 years, and 76.2% +/- 4.1% at 7 years. Patients classified as American Society of Anesthesiologists grade IV had a significantly lower survival rate (24.9%) than those classified as American Society of Anesthesiologists grade II and III (91.9% and 77.3%). During a mean follow-up period of 53.2 +/- 20.1 months (range, 1-84 months), 47 secondary procedures were performed in 31 patients (18.8%). Kaplan-Meier estimates showed a freedom from secondary intervention of 94.7% +/- 1.8%, 81.7% +/- 3.3%, and 77.4% +/- 3.6% at 1, 3, and 7 years, respectively. The reason for secondary treatment was endograft thrombosis in 10 patients (6.1%), persisting primary endoleak in 9 (5.5%), late secondary endoleak in 6 (3.6%), graft migration in 3 (1.8%), aneurysm rupture in 2 (1.2%), and graft infection in 1 (0.6%). Device migration (> or =10 mm) occurred in seven patients (4.2%). Other graft changes, such as graft kinking (n = 4; 2.4%), fracture of metallic stents (n = 2; 1.2%), erosion of the longitudinal bar (n = 2; 1.2%), or modular component separation (n = 1; 0.6%), were rare. Follow-up computed tomographic imaging revealed a decrease of the maximum aneurysm sac diameter (>5 mm) in 106 (64.2%) patients and an increase in 14 (8.5%) patients. The mean aneurysm diameter significantly decreased (P < .001). Of the factors recorded at baseline, only endoleaks showed a significant correlation with the risk of aneurysm increase during follow-up (P < .001). Adverse anatomy (neck diameter >28 mm, neck length <15 mm, and '5 patent aortic branches) did not adversely influence the aneurysm shrinkage rate, the risk for a secondary procedure, or the clinical success rate. A significantly higher rate of clinical success (P < .05) was observed in patients older than 65 years of age.

CONCLUSIONS

Implantation of the Talent endograft device is a safe and effective alternative to open surgery for exclusion of abdominal aortic aneurysm. In comparison with first-generation grafts, the device showed superior durability for as long as 5 to 7 years after implantation. Even if prototypes of the Talent device were implanted in this study, the graft was also successfully used in most patients, even in those with adverse anatomy. Because improvements of the endograft have been made to address connecting bar breaks, a lower incidence of graft limb occlusion can be expected in the future.

Biomechanical determinants of abdominal aortic aneurysm rupture

Rupture of abdominal aortic aneurysm (AAA) represents a significant clinical event, having a mortality rate of 90% and being currently ranked as the 13th leading cause of death in the US. The ability to reliably evaluate the susceptibility of a particular AAA to rupture on a case-specific basis could vastly improve the clinical management of these patients. Because AAA rupture represents a mechanical failure of the degenerated aortic wall, biomechanical considerations are important to understand this process and to improve our predictions of its occurrence. Presented here is an overview of research to date related to the biomechanics of AAA rupture. This includes a summary of results related to ex vivo and in vivo mechanical testing, noninvasive AAA wall stress estimations, and potential mechanisms of AAA wall weakening. We conclude with a demonstration of a biomechanics-based approach to predicting AAA rupture on a patient-specific basis, which may ultimately prove to be superior to the widely and currently used maximum diameter criterion.

Emergency Endovascular Repair for Ruptured Abdominal Aortic Aneurysms: Feasibility and Comparison of Early Results with Conventional Open Repair

PURPOSE

To assess the feasibility of endovascular aortic repair (EVAR) on patients presenting with a ruptured abdominal aortic aneurysm (AAA) in a teaching hospital, and to compare there post-operative outcomes with contemporaneous patients treated with open repair (OR).

METHODS

A series of consecutive of patients presenting ruptured AAA with retro/intraperitoneal haematoma were included in the study. EVAR was attempted whenever possible. In all other cases (severe haemodynamic instability, adverse anatomy, device unavailability), ruptured AAA were treated by OR.

RESULTS

Thirty-seven patients were enrolled between January 2001 and July 2004. Seventeen (46%) patients were treated using adapted designed aortoiliac endografts (eight bifurcated, eight aorto-uniiliac, one iliac extension). Twenty (54%) patients unfit for EVAR because of severe haemodynamic instability (n=8), adverse anatomical configuration (n=7), or unavailability of an appropriate endograft (n=5) were treated by OR. Twenty-seven (73%) had a retrospective suitable anatomy for EVAR. Three early conversions from EVAR to OR were performed. Blood loss, operating time, and intensive care stay were significantly decreased in EVAR patients (respectively: 156 min+/-60, 1520 ml+/-1175, 3 days for EVAR; vs. 222 min+/-82, 3075 ml+/-1750, 13 days for OS; P<.01). The 30-day mortality rate was 23.5% for EVAR vs. 50% for OR (P=0.09).

CONCLUSION

EVAR of ruptured AAA is feasible for selected patients based on haemodynamic and morphologic criteria, and should be associated with improved immediate outcomes as compared with OR. These results should be tempered by the fact that these patients have heavy comorbidities which explains the absence of difference in mid-term mortality rates between the two groups, but should also encourage surgical institutions that are managing such life-threatening emergencies to introduce EVAR as part of their therapeutic arsenal for ruptured AAA.

Aneurysm Diameter and Proximal Aortic Neck Diameter Influence Clinical Outcome of Endovascular Abdominal Aortic Repair: A 4-Year EUROSTAR Experience

Our objective was to evaluate the effect of preoperative aneurysm and aortic neck diameter on clinical outcome after infrarenal abdominal endovascular aneurysm repair (EVAR). Data of patients in the European Collaborators Registry on Stent-Graft Techniques for Abdominal Aortic Aneurysm Repair (EUROSTAR) registry base who underwent EVAR with Talent stent grafts were analyzed. Patient characteristics and clinical outcomes were compared among four groups defined by preoperative abdominal aortic aneurysm (AAA) and proximal aortic neck diameter: A, AAA < or =60 mm and neck < or =26 mm; B, AAA >60 mm and neck < or =26 mm; C, AAA < or =60 mm and neck >26 mm; and D, AAA >60 mm and neck >26 mm. Over a 7-year period, 1,317 patients underwent EVAR. Patients in groups B and D were significantly older and had a higher American Society of Anesthesiologists score compared with groups A and C (p=0.002 and 0.003, respectively). Mortality rate was highest in group D (p=0.002), as were rupture and conversion rates (p=0.015 and 0.037, respectively). This study demonstrates that patients with an AAA >60 mm and a proximal aortic neck >26 mm have worse clinical outcome after EVAR.

What Determines and Are the Consequences of Surveillance Intensity after Endovascular Abdominal Aortic Aneurysm Repair?

Follow-up examinations are advised 1, 3, 6, 12, 18, and 24 months and yearly thereafter by the European Collaborating Group on Stent-Graft Techniques for Abdominal Aortic Aneurysm Repair (EUROSTAR). The aim of this study was to evaluate the determinants and consequences of surveillance completeness. Patients who underwent endovascular abdominal aortic aneurysm repair between October 1996 and August 2004 and enrolled in the EUROSTAR registry were analyzed. Two groups were compared: patients who attended all scheduled visits (group A) and those who came infrequently (group B). Odds ratios and hazard rates (HRs) with 95% confidence intervals (CIs) were determined to detect which patient characteristics and complications were associated with follow-up intensity. Of the 4,433 patients, 1,538 (35%) attended all scheduled visits until the end of follow-up (group A). Analysis of patient characteristics demonstrated that intensive visitors were more often smokers, hyperlipemic, and considered unfit for open surgery or general anesthesia. Complications during follow-up, including endoleaks (24% vs. 20%), kinking (3.5% vs. 2.5%), and migration (4.9% vs. 3.5%), appeared significantly more frequently in group A. Despite intensive follow-up of this category, still a greater proportion died (12% vs. 9%, adjusted HR = 1.5, 95% CI 1.2-1.8). After 84 months of follow-up, the cumulative survival rates in groups A and B were 71% and 74%, respectively (p < 0.0001). It seems that follow-up intensity was based on baseline patient characteristics. High-risk patients had, despite more intensive surveillance, still more complications after adjustment for patient, morphological, and center-specific characteristics. Further assessment is indicated to evaluate the effectiveness of different frequencies of surveillance visits.

Color Duplex Ultrasonography Is Insensitive for the Detection of Endoleak After Aortic Endografting: A Systematic Review

PURPOSE

To synthesize the available evidence regarding the diagnostic accuracy of color duplex ultrasonography (CDU) versus the accepted gold-standard of contrast-enhanced computed tomography (CT) for the detection and classification of endoleaks after aortic endografting.

METHODS

A systematic search of the literature was conducted using electronic bibliographical databases and other means to gather articles published between 1991 and 2004. Articles were scrutinized against inclusion/exclusion criteria that broadly followed the QUADAS quality assessment guidelines. The results of diagnostic CDU were expressed for each study as a 2x2 contingency table, and summary statistics (sensitivity/specificity with 95% confidence intervals [CI]) were calculated. Pooled and random effects meta-analyses were performed.

RESULTS

Eight published studies and 2 unpublished studies from Charing Cross and St. George's Hospitals (711 patients, 1355 paired scans performed > or = 1 month after endografting) were eligible for inclusion. From meta-analyses, the pooled sensitivity of CDU (versus CT as the gold standard) was 69% (95% CI 52% to 87%) and the specificity of CDU was 91% (95% CI 87% to 95%). These parameters did not appear to vary over time when a smaller dataset of 117 patients with 239 paired scans was used to compare CT and CDU specifically at 3, 12, and 24 months after endografting. Endoleak classification data, which was derived from only 5 small studies, indicated that CDU appeared to have better diagnostic accuracy in detecting type I or type III endoleaks compared with type II endoleaks; however, the data were insufficient for statistical analysis.

CONCLUSIONS

CDU currently does not have sufficient diagnostic accuracy for the detection of all endoleaks in routine clinical practice. The diagnostic accuracy of CDU may improve if type II endoleaks are ignored.

Influence of Diabetes Mellitus on the Endovascular Treatment of Abdominal Aortic Aneurysms

PURPOSE

To investigate the influence of diabetes mellitus on outcome after endovascular abdominal aortic aneurysm (AAA) repair.

METHODS

Of 6017 patients enrolled in the EUROSTAR registry after undergoing endovascular AAA repair between May 1994 and December 2003, 731 (12%) had diabetes mellitus (690 men; mean age 72 years, range 37-100). Patient demographics, risk factors, aneurysm morphology, operative and procedural details, complications, major events, and regular follow-up information were compared. The relationships of complications and events to diabetes mellitus, which were tested with multivariate logistic regression analysis and Cox proportional hazards modeling, are expressed as odds ratios (OR) and hazard rates (HR) with 95% confidence intervals (CI). Survival was compared with life-table analysis.

RESULTS

A significantly higher risk of device-related complications was observed in diabetic patients (8% versus 6%, p < 0.049; OR 1.35, 95% CI 1.00 to 1.82). The greatest difference in the groups was in mortality, which was significantly higher in the diabetic population (13%) compared to the nondiabetic patients (10%, p < 0.039; OR 1.27, 95% CI 1.01 to 1.59). Deaths, which occurred at a higher frequency within the 30-day perioperative period in diabetic patients, were primary due to cardiac complications. Insulin-controlled type 2 diabetic patients had significantly lower rates of early and late endoleaks and secondary interventions than diet-controlled type 2 diabetics (p = 0.002, p = 0.0001, and p = 0.0008, respectively) and nondiabetic patients (p = 0.002, p = 0.0005, and p = 0.0025, respectively). The cumulative survival after 48 months did not differ significantly: 74% in diabetics and 79% in the population without diabetes.

CONCLUSIONS

Patients with diabetes mellitus had a significantly higher early mortality rate after EVAR, but their long-term survival was similar to nondiabetic patients.

Endoleak: Treatment Options

Endoleak, also called leakage, leak, and Perigraft leak, is a major complication and its persistence represents a failure of endovascular aortic aneurysm repair (EVAR). Its detection and treatment is therefore of primary importance since endoleak is associated with pressurization (increases pressure) of the sac, resulting in expansion and rupture of the aneurysm. The aim of this article was to discuss the different options to treat endoleak.

Impact of Smoking on Endovascular Abdominal Aortic Aneurysm Surgery Outcome

OBJECTIVE

Smoking plays a major role in deficiencies of the vascular system, and seems to have consequences for the treatment of cardiovascular diseases. We hypothesized that smokers have a higher mortality and more complications after endovascular abdominal aortic aneurysm surgery than non-smokers.

METHODS

We assessed mortality and complications of 3270 patients who underwent endovascular abdominal aortic aneurysm surgery in Europe between January 1994 and July 2001. Survival and (post) operative complications were assessed by smoking status.

RESULTS

Mortality did not significantly differ between smokers and non-smokers. Smokers had a higher number of intra-operative additional procedures, but a lower number of late endoleaks in comparison to non-smokers. In addition, smokers had a reduced risk of late type II endoleaks in comparison with non-smokers.

CONCLUSION

There seems to be no significant difference in endovascular abdominal aortic aneurysm surgery outcome between smokers and non-smokers, although there were significant differences in intra-operative additional procedures and late endoleaks.

Use of abdominal aortic endovascular prostheses in France from 1999 to 2001

BACKGROUND

Since the introduction of endovascular repair (EVR) for infrarenal abdominal aortic aneurysm (AAA), clinical evaluation has been under way in many countries throughout the world. The main purpose of this retrospective study was to determine outcome of EVR with aortic endovascular prostheses (AEPs) and to evaluate the extent to which French practitioners have complied with regulatory and clinical guidelines for the use of these trial devices.

METHODS

This retrospective study was conducted by the French National Health Insurance Fund for Salaried Workers. Data were compiled on EVR procedures performed at health care institutions all over mainland France between June 1999 and May 2001.

RESULTS

A total of 1012 AEPs were deployed for AAA repair in France during the study period. Only 151 (14.9%) of these EVR procedures were carried out within an approved investigational setting with informed patient consent. Only 149 of the 861 patients (17.3%, 95% confidence interval [CI], 14.9 to 19.9%) who underwent endovascular repair in noninvestigational settings signed informed consent forms. In 452 cases (46.5%), the diameter of the AAA was 50 mm or less. Complete outcome data for the first year were available for 891 patients (88%). Complications occurred in 177 of these patients (19.9%, 95% CI, 17.3 to 22.6%). There were a total of 47 deaths (5.3%, 95% CI, 3.9 to 6.9%), including 27 during the first 30 postoperative days. Other major events during the first year after AEP implantation were ruptured AAA in 5 patients, conversion to open operation in 15, and additional endovascular treatment in 52. Data on clinical surveillance were available for 987 patients (97.5%) with a mean follow-up of 345 days. Only 294 patients (29.8%, 95% CI, 27.0 to 32.7%) underwent complete imaging within the first month after AEP implantation. A total of 184 patients (18.6%, 95% CI, 16.3 to 21.2%) received no surveillance at all.

CONCLUSION

This study shows the need for improvement in the clinical evaluation of new devices and medical technologies in France. Study findings also confirm the significant incidence of adverse outcomes and necessity for routine surveillance after EVR of AAA with AEP. However, risk/benefit analysis is difficult because most procedures were not carried out within a proper investigational context.

Endovascular aneurysm repair with a bifurcated endovascular graft at a primary referral center: Influence of experience, age, gender, and aneurysm size on suitability

OBJECTIVE

The purpose of this study was to assess the suitability for endovascular repair of abdominal aortic aneurysm (EVAR) in an unselected patient population.

PATIENTS AND METHODS

Between February 1999 and May 2002 all consecutive patients with a nonemergent abdominal aortic aneurysm (AAA) were prospectively examined with contrast material-enhanced spiral computed tomography (CT). Those patients probably suitable for EVAR on the basis of CT findings underwent calibrated angiography. A panel of radiologists and vascular surgeons reviewed the clinical data and vascular anatomy, and decided on the appropriateness of EVAR with the bifurcated Zenith AAA endovascular graft.

RESULTS

One hundred seven patients were included. Fifty-six patients (52%) had one or more contraindications for EVAR. Unsuitability was most frequently (88%) related to the proximal neck. Inadequate neck length was the most common specific reason. Inadequate iliac anatomy was the reason for unsuitability in 59% of patients. The rate of unsuitability decreased from 61% during the first half of the study to 40% during the second half (P =.03) Unsuitability was equal between men and women. Age and maximum diameter did not differ between candidates and noncandidates.

CONCLUSION

Almost half (48%) of patients with an infrarenal AAA referred to a primary referral center are suitable for EVAR with the bifurcated Zenith AAA endovascular graft. Neck anatomy was the most frequent reason for rejection. Rate of suitability increased over time, probably as a result of increasing experience. Suitability was not influenced by gender, age, or aneurysm size.

Comparison of minimal incision aortic surgery with endovascular aortic repair

BACKGROUND

Enthusiasm for endovascular aortic repair (EVAR) has been tempered by midterm outcomes that raise valid concern about long-term durability.

METHODS

This article compares outcome data from a prospective nonrandomized comparison of a less-invasive open surgical repair technique-minimal incision aortic surgery (MIAS)-and EVAR.

RESULTS

MIAS and EVAR had comparable intensive care unit stays (1 day or less), quick return to general dietary feeding (2 days), and comparable hospital length of stay (4.8 days [3.4 days for uncomplicated cases MIAS] and 2.0 days for EVAR). Overall morbidity and mortality for MIAS and EVAR were comparable (18% versus 27%). MIAS was more cost effective than EVAR (net revenue MIAS = +8,445 US dollars, EVAR -7,263 US dollars).

CONCLUSIONS

MIAS is a safe, cost-effective alternative to endovascular aortic repair.

Emergency treatment of acute symptomatic or ruptured abdominal aortic aneurysm. Outcome of a prospective intent-to-treat by EVAR protocol

OBJECTIVE

Outcome of treatment of patients with ruptured or symptomatic non-ruptured aneurysm (rAAA and snrAAA), preferentially treated by emergency endovascular repair was assessed. The outcome was compared with a historical group of patients treated by open repair.

PATIENTS AND METHODS

Two groups of patients presenting with acute symptomatic AAA were compared. Group I (study group) consisted of 40 consecutive prospectively enrolled patients from May 2001 until June 2002, in whom emergency endovascular abdominal aortic aneurysm repair (e-EVAR) was the preferential management. Short or wide neck or profound hypovolemic shock were exclusion criteria for e-EVAR. Group II (control group) consisted of 28 patients, retrospectively analysed, all treated by conventional surgical repair between January 1999 and May 2001. In group I, 26 patients had rAAA and in group II 22 patients. The other patients had snrAAA.

RESULTS

In group I, 14 patients were treated by open repair. Unsuitable anatomy or profound hypovolemia was the cause of open repair in eight patients, while logistic reasons were the reasons for use of open repair in six patients (off-protocol use of open surgery). Thus, in this prospective series the feasibility of EVAR was 80% (32/40). Patient characteristics, proportion rAAA or hemodynamically unstable patients were comparable in group I and II. Volume of blood loss and need for fluid transfusion were significantly less in group I compared to group II. The perioperative mortality in group I was significantly less than in group II (20% vs. 43%, respectively, p = 0.04). If patients with rAAA were considered the mortality was 31% in group I and 50% in group II, which difference did not reach the level of statistical significance.

CONCLUSION

e-EVAR was a feasible treatment in the majority of patients with rAAA and snrAAA. Blood loss and the requirements of fluid transfusion were significantly decreased. Most importantly in this institutional series significantly lower first-month mortality was observed in the group with preferential e-EVAR compared to a control group. A multi-center study assessing the outcome of preferential use of e-EVAR in patients with acute symptomatic AAA is required.

Cardiac risk stratification in patients undergoing endoluminal graft repair of abdominal aortic aneurysm: a single-institution experience with 365 patients

OBJECTIVE

Patients undergoing abdominal aortic aneurysm repair have a high incidence of coexisting cardiac disease. The traditional cardiac risk stratification for open abdominal aortic aneurysm surgery may not apply to patients undergoing endoluminal graft exclusion. The purpose of this study was to examine predictive risk factors for perioperative cardiac events.

METHODS

As part of multiple prospective endograft trials approved by the US Food and Drug Administration, data for 365 patients who underwent endoluminal graft repair from 1996 to 2001 were collected. Variables included for analysis were age and sex; history of smoking; presence of hypertension, diabetes mellitus, or renal insufficiency; Eagle clinical cardiac risk factors; American Society of Anesthesiologists index; type of anesthesia administered; estimated blood loss; preoperative hemoglobin level; preoperative use of beta-blocker therapy; duration of surgery; need for iliac artery conduit; and concomitant other vascular procedures. Univariate and multivariate logistic regression analysis were used to determine which variables were predictive of an adverse perioperative cardiac event, eg, Q wave and non-Q wave myocardial infarction (MI), congestive heart failure (CHF), severe arrhythmia, and unstable angina.

RESULTS

The study cohort included 322 men and 43 women (mean age, 74.2 years). Fifty-two (14.2%) postoperative cardiac events occurred: severe dysrhythmia in 15 patients (4.1%), MI in 14 patients (3.8%), non-Q wave MI in 8 patients (2.2%), CHF in 8 patients (2.2%), and unstable angina in 7 patients (1.9%). Univariate analysis demonstrated that age 70 years or older (P =.034), history of MI (P =.018), angina (P =.004), history of CHF (P <.001), two or more Eagle risk factors (P <.001), and lack of use of preoperative beta-blocker therapy (P =.005) were predictors of perioperative cardiac events. Multivariate analysis identified only age 70 years or older (P =.026), history of MI (P =.024) or CHF (P =.001), and lack of use of preoperative beta-blocker therapy (P =.007) as independent risk factors for an adverse cardiac event.

CONCLUSIONS

Age 70 years or older, history of MI or CHF, and lack of use of preoperative beta-blocker therapy are independent risk factors for perioperative cardiac events in patients undergoing endoluminal graft repair.

Technique and results of transfemoral superselective coil embolization of type II lumbar endoleak

OBJECTIVE

This study was undertaken to describe the technique of transfemoral superselective coil embolization of type II endoleak and its influence on abdominal aortic aneurysm diameter.

METHODS

Over 23 months, 104 aortic stent grafts were deployed to exclude abdominal aortic aneurysms, at an academic medical center. Increase in aneurysm diameter and perigraft findings on contrast material-enhanced computed tomography scans prompted arteriography. Procedures were performed solely by vascular surgeons in a surgical angiography suite. In 7 patients aneurysm access was via the iliolumbar branches of the internal iliac artery, and in 1 patient aneurysm access was via the inferior mesenteric artery through the arc of Riolan from the superior mesenteric artery. Coaxial catheters were placed to gain access to the aneurysm (8F to 5F to 3F, or 5F to 3F). A 3F Tracker18 was the most distal catheter through which an assortment of 0.018 microcoils were deployed within the aneurysm, and the origin of the feeding vessels when possible.

RESULTS

Aneurysm diameter increased 0.48 +/- 0.2 cm over 10.8 +/- 5 months before superselective coil embolization. In 6 of 8 patients superselective coil embolization embolization resulted in a mean decrease in aneurysm diameter of 1.3 +/- 1.2 cm over 9 +/- 3.2 months. Failure was presumed due to inability to reach the aneurysm sac in 1 patient and was associated with oral anticoagulation in 1 other patient.

CONCLUSION

Proper identification of the source of type II endoleak and its complete occlusion, combined with aneurysm sac coiling, may result in prompt decrease in aneurysm size.