Sac behavior after aneurysm treatment with the Gore Excluder low-permeability aortic endoprosthesis: 12-month comparison to the original Excluder device

Long Term Outcomes of the Gore Excluder Low Permeability Endoprosthesis for the Treatment of Infrarenal Aortic Aneurysms

OBJECTIVE

This study evaluated the long term outcomes of endovascular aneurysm repair using the Gore Excluder Low Permeability (LP) endoprosthesis across high volume Dutch hospitals.

METHODS

A retrospective analysis was conducted of patients treated with the Excluder LP for infrarenal abdominal aortic aneurysm (AAA) in four hospitals between 2004 and 2017. Primary outcomes were overall survival, freedom from re-interventions (overall, inside and outside instructions for use, IFU), and AAA sac dynamics: growth (> 5 mm), stabilisation, and regression (< 5 mm). Secondary outcomes were technical success (device deployment), procedural parameters, and re-interventions. Follow up visits were extracted from patient files, with imaging assessed for complications and AAA diameter.

RESULTS

Five hundred and fourteen patients were enrolled, with a median (IQR) follow up of 5.0 (2.9, 6.9) years. Survival rates were 94.0% at one year, 73.0% at five years, and 37.0% at 10 years, with freedom from re-interventions of 89.0%, 79.0%, and 71.0%, respectively. 37.9% were treated outside IFU, leading to significantly more re-interventions over 10 years compared with those treated inside IFU (36.0% vs. 25.0%, respectively; p = .044). The aneurysm sac regressed by 53.5% at one year, 65.8% at five years, and 77.8% at 10 years, and grew by 9.8%, 14.3%, and 22.2%, respectively. Patients with one year sac growth had significantly worse survival (p = .047). Seven patients (1.4%) had a ruptured aneurysm during follow up. Over 15 years, type 1a endoleak occurred in 5.3%, type 1b in 3.1%, type 3 in 1.9%, type 4 in 0.2%, and type 2 in 35.6% of patients.

CONCLUSION

This multicentre study of real world endovascular aneurysm repair data using the Gore Excluder LP endoprosthesis demonstrated robust long term survival and re-intervention rates, despite 37.9% of patients being treated outside IFU, with type 4 endoleak being rare. Treatment outside IFU significantly increased re-intervention rates and one year sac growth was associated with statistically significantly worse survival.

Correlative effect between sac regression and patient longevity following endovascular solution for abdominal aortic aneurysms: an international analysis

INTRODUCTION

Since the introduction of endovascular aortic repair (EVAR) it has become the mainstay treatment for abdominal aortic aneurysms. Several EVAR devices exist commercially, yet, the Terumo Aortic Fenestrated Anaconda™ endograft has demonstrated outstanding results. Evidence in the literature suggests that sac regression could be linked to patient survival and longevity. The main scope of this study is to evaluate sac regression and survival achieved using the Fenestrated Anaconda™ endograft and to discuss relevant literature.

MATERIALS AND METHODS

The current study represents a nine-year cross-sectional international analysis of custom-made Fenestrated Anaconda™ device. For the statistical analysis, SPSS 28 for Windows and R were utilised. Pearson chi-square analysis was used to assess differences in cumulative distribution frequencies between select variables. Statistical significance for all two-tailed tests was set at p < 0.05.

RESULTS

A total of 5,058 patients received the Fenestrated Anaconda™ in this study, either due to unsuitable/complex anatomy for competitor devices (n = 3,891) or based on surgeon preference (n = 1,167). A sac regression of 0-30% was observed in 4,772 (94.3%) over the first four years post-EVAR. Here, 99.6% of patients receiving the Fenestrated Anaconda™ due to unsuitable/complex anatomy for competitor devices and 76.8% based on surgeon preference had 0-30% sac regression. During years 5-9 of follow-up, all patients had 20-45% sac regression. Patient survival during the first six years post-EVAR was 100% but dropped to 77.1% in years 7-9. Survival differed between categorical patient subsets based on the indication.

DISCUSSION

The Fenestrated Anaconda™ has been proven to be a highly effective EVAR endograft. Evidence in the literature clearly demonstrates that sac regression is an accurate prognostic factor for patient survival and longevity.

Long-term outcome results after endovascular aortoiliac aneurysm repair with the bifurcated EXCLUDER Endoprosthesis

OBJECTIVE

To report the long-term outcome of patients presenting with an aortic, aortoiliac, or isolated common iliac aneurysm treated with the bifurcated EXCLUDER Endoprosthesis. Furthermore, potential differences in late outcome results between the original- and low-permeability endoprosthesis were analyzed.

METHODS

A retrospective analysis of prospectively collected data of 182 patients who underwent endovascular aneurysm repair with the EXCLUDER Endoprosthesis between June 1998 and October 2015 in an academic, tertiary care center for aortic disease was performed. Patient follow-up was from 3 to 20 years (mean follow-up of 6.9 years). Primary end points were overall survival and reintervention-free survival. Secondary end points were device-related complications, endoleaks, and reinterventions.

RESULTS

Overall survival at 5, 10, and 15 years was 72.8%, 42.1%, and 12.2%, respectively, with no aneurysm-related mortality and no difference in overall survival between the original- vs low-permeability endoprosthesis group (P = .617). Freedom from type I endoleak at 5 years was 94.8%. No new type I endoleak was detected beyond the 5-year follow-up mark. No type III endoleak was identified. Reintervention-free survival was 83.6%, 66.7%, and 66.7% at 5-, 10-, and 15-year follow-up, respectively. There was a significant difference in intervention-free survival between the original- vs low-permeability endoprosthesis group (P = .029) and after the 5-year follow-up mark. In addition, patients with the low-permeability endoprosthesis showed significantly fewer device-related complications (P = .002) and endoleaks (P = .005).

CONCLUSIONS

Endovascular aneurysm repair using the EXCLUDER Endoprosthesis is effective and durable on long-term follow-up, with acceptably low device-related complications and reinterventions. The low-permeability endoprosthesis was associated with significantly fewer new device-related complications and endoleaks after 5 years of follow-up.

Endotension: twenty years of a controversial term

Use of the term endotension in the treatment of aortic aneurysm is currently controversial. Initially it was proposed to define the circumstance in which there is an enlargement of the aneurysm sac after endovascular repair without a demonstrable endoleak. The term was established with the aim of transmitting the possibility of causes other than pressure applying stress to the aneurysm wall. Twenty years have passed since the proposal of this terminology was published. The literature is reviewed with the purpose of providing an update on advances in the knowledge of the possible etiological mechanisms. The experimental studies call into question that causes other than pressure determine the increase of the aneurysm. On the basis of this review, the term `Sac Expansion Without Evident Leak´ (SEWEL) is proposed as a more accurate and precise denomination for what is aimed to be defined. Evidence suggests that the more likely mechanisms of persistent pressurization of the aneurysm sac are an unidentified endoleak (likely type I or low-flow Type II) or thrombus occluding wide and short channels that connects with the excluded aneurysm sac (at the attachment sites of the stent-graft or at the branch vessels orifices).

Statins Reduce Abdominal Aortic Aneurysm Growth, Rupture, and Perioperative Mortality: A Systematic Review and Meta-Analysis

Background

There are no recognized pharmacological treatments for abdominal aortic aneurysms (AAA), although statins are suggested to be beneficial. We sought to summarize the literature regarding the effects of statins on human AAA growth, rupture, and 30‐day mortality.

Methods and Results

We conducted a systematic review and meta‐analysis of randomized and observational studies using the Cochrane CENTRAL database, MEDLINE, and EMBASE up to June 15, 2018. Review, abstraction, and quality assessment were conducted by 2 independent reviewers, and a third author resolved discrepancies. Pooled mean differences and odds ratios with 95% confidence intervals were calculated using random effects models. Heterogeneity was quantified using the I² statistic, and publication bias was assessed using funnel plots. Our search yielded 911 articles. One case‐control and 21 cohort studies involving 80 428 patients were included. The risk of bias was low to moderate. Statin use was associated with a mean AAA growth rate reduction of 0.82 mm/y (95% confidence interval 0.33, 1.32, P=0.001, I²=86%). Statins were also associated with a lower rupture risk (odds ratio 0.63, 95% confidence interval 0.51, 0.78, P<0.0001, I²=27%), and preoperative statin use was associated with a lower 30‐day mortality following elective AAA repair (odds ratio 0.55, 95% confidence interval 0.36, 0.83, P=0.005, I²=57%).

Conclusions

Statin therapy may be associated with reduction in AAA progression, rupture, and lower rates of perioperative mortality following elective AAA repair. These data argue for widespread statin use in AAA patients.

Clinical Trial Registration

URL: http://www.crd.york.ac.uk. Unique identifier: CRD42017056480.

Prognostic Value of Initial Aneurysmal Sac Regression after EVAR

BACKGROUND

The objective of the study was to evaluate the impact of initial aneurysmal sac reduction after endovascular aneurysm repair on the evolution of aneurysmal sac over follow-up.

METHODS

A retrospective cohort study was made of patients subjected to elective treatment between January 2005 and December 2014, with a minimum follow-up of 18 months. An analysis was made of the evolution of the aneurysmal sac according to its condition one year after surgery, defining of two groups: A (sac reduction) and B (stable sac). Follow-up by computed tomography (CT) angiography was made after one month and then every 6 months or annually, depending on the presence of endoleak.

RESULTS

A total of 128 patients were included. Fifty-one patients (39.8%) showed a significant decrease in diameter during the first year (group A), whereas 77 patients (60.2%) showed no initial decrease (group B). Preoperative CT angiography showed the patients in group A to have larger aneurysms (63.5 mm vs. 59.25; P = 0.048), a greater presence of posterior thrombus (68.6% vs. 30.7%; P < 0.001), and fewer patent lumbar vessels (56.9% vs. 83.1%; P = 0.001). The prevalence of endoleak at some point during follow-up was lower in group A (31.4% vs. 74% in group B; P < 0.001), and 100% of all aneurysmal growths were associated to the presence of endoleak. After 5 years, significant differences were observed in the growth-free rate (96.9% in group A vs. 85.2% in group B; hazard ratio [HR] 4.8 [1.1-21.4; P = 0.036]) and in the reintervention-free rate (95,7% vs. 84.6%; HR 6.6 [0.8-52.4; P = 0.07]). No reoperation in group A was due to type II endoleak.

CONCLUSIONS

The aneurysmal sac can be expected to take a favorable course in those cases characterized by initial aneurysmal sac reduction. These findings may imply a change in the follow-up protocol, even in cases with type II endoleak.

Aortic Aneurysm Rupture After Urokinase Treatment for Acute Limb Ischemia in Two Patients After EVAR

Endovascular aneurysm repair (EVAR) is first-choice treatment for many patients with abdominal aortic aneurysms. Complications unique to endovascular treatment include endoleak and endotension, which can eventually lead to rupture. We present two cases of late aortic rupture after EVAR, where both patients had recent preceding catheter-directed thrombolysis with urokinase for acute limb ischemia. These cases suggest a relation between thrombolytic therapy and aortic rupture after EVAR, and we should therefore be aware of this possible complication.

Outcomes of type II endoleaks after endovascular abdominal aortic aneurysm (AAA) repair: a single-center, retrospective study

PURPOSE

This study aims to determine incidence and outcomes of type II endoleaks (T2E) after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

A retrospective review of procedural angiograms, computed tomography angiography, and medical records of 202 patients who underwent EVAR with the Gore Excluder stent graft was performed to determine presence and outcomes of T2E.

RESULTS

Median follow-up time for 163 patients meeting inclusion criteria [136 males (83%)] was 24.7 months (range=0.5-85.2 months). T2E occurred in 66/163 patients (40.5%). Aneurysm sac size was unchanged in 32/66 patients (48.5%), decreased in 22/66 (33.3%), and increased in 12/66 (18.2%). No aneurysm ruptures, conversion to open repair, or aneurysm-related deaths occurred.

CONCLUSION

T2E are a common occurrence after EVAR, often with benign outcome. However, routine surveillance should be performed, particularly in patients with persistent endoleak or sac growth.

Current aortic endografts for the treatment of abdominal aortic aneurysms

Endovascular Aneurysm Repair is a widely adopted method of treatment for patients with abdominal aortic aneurysms. The minimally invasive approach offered with EVAR has become popular not only among physicians and patients, but in the medical device industry as well. Over the past 25 years the global market for aortic endografts has increased rapidly, resulting in a wide range of devices from various companies. Currently, there are seven endografts approved by the FDA for the treatment of abdominal aortic aneurysms. These devices offer a wide range of designs intended to increase inclusion criteria while decreasing technical complications such as endoleak and migration. Despite advances in device design, secondary interventions and follow-up requirements remain a significant issue. New devices are currently being studied in the U.S. and abroad and may significantly reduce complications and secondary interventions.

Systolic Sac Pressure Index for the Prediction of Persistent Type II Endoleak for 12 Months After Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

To assess the relationship between the systolic sac pressure index (SPI) and the presence of endoleaks 12 months after endovascular abdominal aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

We performed a single-center prospective trial of consecutively treated patients. SPI (calculated as systolic sac pressure/systolic aortic pressure) was measured by catheterization immediately after EVAR. Contrast-enhanced computed tomography was scheduled 12 months after EVAR to detect possible endoleaks.

RESULTS

Data were available for 34 patients who underwent EVAR for an AAA. Persisting type II endoleak was found in 8 patients (endoleak-positive group) but not in the other 26 patients (endoleak-negative group). The mean ± standard deviation SPI was significantly greater in the endoleak-positive group than in the endoleak-negative group (0.692 ± 0.048 vs. 0.505 ± 0.081, respectively; P = .001). Receiver-operating characteristic curve analysis revealed that an SPI of 0.638 was the optimum cutoff value for predicting a persistent endoleak at 12 months with high accuracy (0.971; 33/34), sensitivity (1.00), and specificity (0.962) values. The mean change in AAA diameter was -4.28 ± 5.03 mm and 2.22 ± 4.54 mm in patients with SPI of <0.638 or ≥0.638, respectively (P = .002).

CONCLUSION

Patients with an SPI of ≥0.638 immediately after EVAR were more likely to have a persistent type II endoleak at 12 months with an accuracy of 0.971, and showed increases in aneurysm sac diameter compared with patients with an SPI of <0.638.

Short-Term Outcomes of Management of Endovascular Aneurysm Repair in Patients With Dilated Iliacs

OBJECTIVES

This study aims to evaluate outcomes following endovascular aneurysm repair (EVAR) in patients with dilated but not aneurysmal common iliac arteries.

METHODS

Data prospectively collected from 342 elective EVARs were analyzed retrospectively. Dilated common iliac anatomy was defined as 21 to 24 mm. Patients with iliac aneurysms or external iliac artery (EIA) extension were excluded. Patients were followed up using clinical review, plain radiographs, duplex imaging, and selective computed tomography scanning.

RESULTS

Median age was 75 years with a mean follow-up of 3.6 years. In all, 33 patients had dilated common iliac arteries (DCIAs) and 309 had non-dilated common iliac arteries (NDCIA). There was no difference in aneurysm diameter or neck characteristics (length, diameter, angulation, thrombus, and flare) between the subgroups. There was no significant difference in technical success, 30-day mortality, late mortality, aneurysm-related mortality, 30-day reinterventions, stent graft migration, limb occlusion, sac expansion, graft rupture, type 1 endoleaks, type 3 endoleaks, and total reinterventions (all Ps > .05). There was a significant decrease in type II endoleaks in patients with DCIA compared to NDCIA (NDCIA 12.9% and DCIA 0.0%; P = .02).

CONCLUSION

Patients presenting with abdominal aortic aneurysms with DCIA can be successfully treated with EVAR with no increase in complications without extension into the EIA.

A technique for endograft relining of a type IV endoleak using a surgeon-modified internal gate

Type IV endoleaks represent a rare etiology of late endograft failure; however, depending on the location, they can be extremely challenging to repair with endovascular solutions. We present a method of endograft relining that preserves antegrade limb perfusion, avoids extra-anatomic reconstructions, and ensures complete endograft exclusion.

Endovascular treatment of perigraft seroma after open abdominal aortic aneurysm repair: report of a case

Perigraft seroma is a rare complication after open abdominal aortic aneurysm (AAA) repair. We successfully treated large seroma after expanded polytetrafluoroethylene (ePTFE) aortobiiliac graft repair endovascularly. The patient was an 81-year-old lady with the history of five times laparotomy. She could not take any food because of vomiting. Contrast enhanced computed tomography (CT) revealed giant seroma compressing small intestine. Total relining of the graft with a Excluder(TM) endoprosthesis and open drainage of the seroma was performed. After the surgery, she became asymptomatic and seroma disappeared by CT 2 years later. This modality would be a good option for this rare complication.

Outcomes of endovascular aneurysm repair in patients with hostile neck anatomy

OBJECTIVES

This study aims to evaluate outcomes following EVAR in patients with hostile neck anatomy (HNA).

METHODS

Data prospectively collected from 552 elective EVARs were analysed retrospectively. Data regarding neck morphology was obtained from aneurysm stent plans produced prior to EVAR. HNA was defined as any of; neck diameter >28 mm, neck angulation >60°, neck length <15 mm, neck thrombus, or neck flare.

RESULTS

552 patients underwent EVAR. Mean age 73.9 years, mean follow-up 4.1 years. 199 patients had HNA, 353 had favourable neck anatomy (FNA). There was a significant increase in late type I endoleaks (FNA 4.5%, HNA 9.5%; P = 0.02) and total reinterventions (FNA 11.0%, HNA 22.8%; P < 0.01), and a significant decrease in late type II endoleaks in patients with HNA (FNA 16.7%, HNA 10.6%; P < 0.05). There was no significant difference in technical success (FNA 0.6%, HNA 2.0%; p = 0.12), 30-day re-intervention (FNA 2.8%, HNA 5.0%; P = 0.12), 30-day mortality (FNA 1.1%, HNA 0.5%; P = 0.45), 30-day type I endoleaks (FNA 0.8%, HNA 2.5%; P = 0.12), 5-year mortality (FNA 15.1%, HNA 14.6%; P = 0.86), aneurysm-related mortality (FNA 1.7% versus HNA 2.0%; P = 0.79), stent-graft migration (FNA 2.5%, HNA 3.0%; P = 0.75), sac expansion (FNA 13.0%, HNA 9.5%; P = 0.22), or graft rupture (FNA 1.1%, HNA 3.5%; P = 0.05). Binary logistic regression of individual features of HNA revealed secondary intervention (P = 0.009), technical failure (P = 0.02), and late type I endoleaks (P = 0.002), were significantly increased with increased neck diameter.

CONCLUSIONS

HNA AAAs can be successfully treated with EVAR. However, surveillance is necessary to detect and treat late type I endoleaks in HNA patients.

Successful endovascular management of an aortic rupture following stent placement for severe atherosclerotic stenosis: A case report

Aortic rupture during endovascular procedures is a devastating complication that mandates expedient intervention. The present report describes a case in which endovascular treatment was used to successfully manage an aortic rupture following placement of a covered stent graft for severe infrarenal aortic stenosis. Successful management of this case was the result of the procedure being performed in an operating room under appropriate anesthesia and close hemodynamic monitoring. Bilateral common femoral arterial access and use of covered aortic stent grafts also contributed to a favourable outcome.

Thoracic aortic aneurysms and dissections: endovascular treatment

The treatment of thoracic aortic disease has changed radically with the advances made in endovascular therapy since the concept of thoracic endovascular aortic repair was first described 15 years ago. Currently, there is a diverse array of endografts that are commercially available to treat the thoracic aorta. Multiple studies, including industry-sponsored and single-institution reports, have demonstrated excellent outcomes of thoracic endovascular aortic repair for the treatment of thoracic aortic aneurysms, with less reported perioperative morbidity and mortality in comparison with conventional open repair. Additionally, similar outcomes have been demonstrated for the treatment of type B dissections. However, the technology remains relatively novel, and larger studies with longer term outcomes are necessary to more fully evaluate the role of endovascular therapy for the treatment of thoracic aortic disease. This review examines the currently available thoracic endografts, preoperative planning for thoracic endovascular aortic repair, and outcomes of thoracic endovascular aortic repair for the treatment of both thoracic aortic aneurysms and type B aortic dissections. Mt Sinai J Med 77:256-269, 2010. (c) 2010 Mount Sinai School of Medicine.

Five-year results for the Talent enhanced Low Profile System abdominal stent graft pivotal trial including early and long-term safety and efficacy

OBJECTIVES

The pivotal trial of the Talent enhanced Low Profile System (eLPS; Medtronic Vascular, Santa Rosa, Calif) stent graft evaluated short and long-term safety and efficacy of endovascular aneurysm repair (EVAR). These data and a confirmatory group assessing the performance of the CoilTrac delivery system supported the United States premarket approval application for the device.

METHODS

The pivotal trial was a prospective, nonrandomized study conducted at 13 sites from February 2002 to April 2003. The study group (n = 166) underwent EVAR using the Talent eLPS stent graft. The control group (n = 243) underwent open surgical AAA repair. Data for this group were obtained from the Society for Vascular Surgery Endovascular AAA Surgical Controls project. Outcomes were compared at 30 days and 12 months. Additional 5-year follow-up was obtained for the eLPS group. A single-center cohort of 137 patients was the confirmatory group for the assessment of the clinical performance of the CoilTrac delivery system, with analysis of outcomes <or=30 days from the procedure.

RESULTS

AAA anatomy with neck length as short as 3 mm and maximum neck diameter of 32 mm were included in the eLPS group. EVAR was superior to open repair for periprocedural outcomes, including mean procedure duration (167.3 vs 196.4 minutes, P < .001), blood transfusion (18.2% vs 56.8%, P < .001), median intensive care unit stay (19.3 vs 74.3 hours, P < .001), and mean hospital stay (3.6 vs 8.2 days, P < .001). Freedom from major adverse events was 89.2% for EVAR at 30 days vs 44.0% (P < .001) and 81.3% vs 42.4% at 1 year (P < .001). Freedom from all-cause mortality and aneurysm-related mortality (ARM) was 93.7% and 98.2% for EVAR vs 92.4% and 96.7% for the controls. Through 5 years for the EVAR group, rates of freedom from all-cause mortality, ARM, aneurysm rupture, and conversion to surgery were 69.8%, 96.5%, 98.2%, and 99.1%, respectively, with one conversion to surgery, 25 secondary reinterventions, and five site-reported instances of stent graft migration. The technical success rate for the CoilTrac confirmatory group was 100%, with no aneurysm rupture or conversion to open repair at 30 days. The 30-day all-cause mortality rate was 1.5% (2 of 137).

CONCLUSIONS

In a population with challenging anatomic characteristics, EVAR with the Talent eLPS and use of the CoilTrac delivery system compared favorably with open repair through 1 year. Sustained protection from ARM, with minimal reinterventions, was attained through 5 years.

Endovascular device design in the future: transformation from trial and error to computational design

Endovascular devices have been designed by trial and error, with bench and animal testing followed by human clinical trials to determine whether the devices are safe and effective. Despite remarkable advances over the past 15 years, there are persistent concerns regarding the long-term durability of endovascular devices. This may be due to deficiencies in device design, which has lagged behind other industries in adopting computational methods that are now routinely used to design, develop, and test new aircraft and automobiles. Similar computational design and failure mode simulations that evaluate performance under stress conditions have not been widely applied in the development of endovascular devices. Advances in medical imaging and computational modeling now allow simulation of physiological conditions in patient-specific 3-dimensional vascular models, which can provide a framework to design and test the next generation of endovascular devices. This modeling will allow the prospective design of devices that can withstand the force variations in the cardiovascular system that occur during bending, coughing, and varying degrees of exercise, as well as the extremes encountered during sudden impact in contact sports. Utilization of computational design methodology that takes into consideration the physiology of the cardiovascular system will improve future endovascular devices so that they are safer and more effective and durable.

Is F 18 Fluorodeoxyglucose Positron Emission Tomography Too Sensitive for the Diagnosis of Vascular Endograft Infection?

We report a case of a false positive fluorodeoxyglucose positron emission tomography (FDG-PET) scan in a patient who presented with abdominal pain, and gastrointestinal bleeding accompanied by elevation of inflammatory markers, seven weeks after a proximal type I endoleak repair with a cuff extension. Aortoenteric fistula and endograft infection was ruled out by laparotomy. FDG-PET image may have a role in diagnosis of infection, but false positive results are possible and caution is necessary if other data are non-confirmatory.

Endotension following endovascular aneurysm repair

Abstract

Endovascular aneurysm repair (EVAR) is a new and minimally invasive alternative to open repair for patients with abdominal aortic aneurysm (AAA). Soon after its introduction in 1990, it was recognized that EVAR had potential and distinct advantages in the elective and emergency settings. However, long-term follow-up has shown enlargement of the AAA in a substantial percentage of patients who underwent EVAR with the original-permeability Excluder. Of interest is that sac expansion frequently occurs in the absence of endoleak, often referred to as endotension. The pathophysiology of endoleak is beginning to be elucidated and its management is ready to be established, while controversy still exists about the etiology and clinical consequences of endotension. Fortunately, the incidence of endotension is decreasing and it appears that AAA expansion after EVAR with the original Excluder can be arrested by endovascular relining with a low-permeability Excluder endoprosthesis. The aim of this brief review is to provide historical perspective and a good understanding of the etiology, diagnosis, and management of endotension.

How to design the optimal stent graft--what have we learnt?

It is now more than 20 years since the first report of stent graft insertion in the human arterial system was published. The first "homemade" devices proved that the technique was possible but could not show any durability. Using these devices, it was possible to get a good seal but not a good anchorage. Not even the first generation of commercially available stent grafts proved to be durable. First after gaining knowledge about the forces acting on the stent graft, it was realized that attachment was important for the durability and the hooks and barbs or a longitudinal stability are needed to minimise the risk for distal migration. Not much of a difference in the overall performance is noticed between the ePTFE graft or the polyester graft or when comparing stainless steel stents with those made out of nitinol. The systems are made much more flexible and hydrophilic leading to a better performance and a greater chance of percutaneous approach. The optimal stent graft is not out on the market yet, but hopefully will come with further development.

A randomized, placebo-controlled trial of doxycycline after endoluminal aneurysm repair

BACKGROUND

The late durability of endovascular aneurysm repair (EVAR) has been limited by progressive aortic degeneration believed to be mediated by matrix metalloproteases (MMP). The goal of this study was to evaluate the effect of a MMP inhibitor, doxycycline, on EVAR.

METHODS

Patients undergoing EVAR were randomized to doxycycline (100 mg twice daily) or placebo for 6 months following the procedure. Clinical data, blood samples, and computed tomography (CT) scans were obtained preoperatively, postoperatively (blood only), and at 1- and 6-month follow-up. Forty-four subjects were analyzed based on intention-to-treat.

RESULTS

Plasma MMP-9 decreased significantly below baseline in the doxycycline (N = 20) treated patients at 6 months (-16.4% +/- 20.7%, P < .05) while there was a nonsignificant increase in the placebo (N = 24) group (128.1% +/- 73.5%). This was primarily related to changes between 1 and 6 months. In patients with endoleaks at 6 months, plasma MMP-9 increased in 83% of the placebo treated patients, but in only 14% of the doxycycline treated group (P < .03). Among endoleak-free patients with AneuRx or Excluder endografts, doxycycline treatment resulted in greater decreases in maximum aortic diameter than placebo treatment (-13.3% +/- 3.3% vs -3.8% +/- 3.0%, P < .05). Furthermore, doxycycline treatment significantly reduced the aortic neck dilatation at 6 months in Excluder treated patients.

CONCLUSION

There is evidence of persistent MMP release representing ongoing aortic degradation after endografting which can be inhibited by doxycycline therapy. In analyses based on the endograft used, treatment with doxycycline also demonstrated evidence of increased aortic dimensional stability, a surrogate marker for long-term success of EVAR. Although encouraging, these results require confirmation in larger patient populations. Doxycycline should undergo more thorough evaluation as a potential adjuvant treatment to improve the results of EVAR, particularly in certain subgroups.