One-year outcomes from an international study of the Ovation Abdominal Stent Graft System for endovascular aneurysm repair

Comparative study of acute kidney injury in pararenal aortic aneurysm: open surgical versus endovascular repair

Background

Pararenal abdominal aortic aneurysms (PR-AAA), constituting around 15%-20% of AAA patients, are defined as having no neck between the aneurysm and the renal arteries. Due to an insufficient sealing zone, open surgical repair (OSR) is the gold standard, while EVAR is reserved for those unfit for surgery. Renal outcomes disturb long-term survival, and they have massive socioeconomic and quality of life implications, especially if patients require dialysis.

Methods

This study aims to elucidate any difference between EVAR and OSR of PR-AAA, excluding suprarenal aneurysms, with specific emphasis on renal dysfunction over the short and long term. An existing database of PR-AAA between 2002 and 2023 was used to glean information regarding the therapeutic option used. Renal events were defined by the RIFLE criteria. Out of 1,563 aortic interventions, we identified 179 PR-AAA, of which 99 high-risk patients had an aortic neck of less than 10 mm with complete follow-up. We excluded patients with fenestrated EVAR (FEVAR), branched EVAR (BEVAR), or chimney EVAR (Ch-EVAR) and any patients requiring visceral artery reimplantation.

Results

In total, 63 patients underwent EVAR, and 36 required OSR. 17.46% of patients who underwent EVAR experienced acute kidney injury (AKI) compared with 36.11% of the OSR group (P = 0.037). The mean post-op creatinine for OSR was 109.88 µmol/L, and for EVAR was 127.06 µmol/L (P = 0.192). The mean difference between long-term (9-12 years) creatinine values in OSR was 14.29 µmol/L (P = 0.191), and the mean difference for EVAR was 25.05 µmol/L (P = 0.024). Furthermore, 27.8% of OSR patients who underwent Left Renal Vein Division and Ligation (LRVDL) experienced an AKI, while 50% who did not undergo LRVDL experienced an AKI (P = 0.382). Thirty-day morbidity in the EVAR group (20.97%) was significantly lower than in the OSR group (42.62%) (P = 0.022). Moreover, 3.17% in EVAR group and 7.14% in OSR group had aneurysm-related mortality (P = 0.584).

Conclusion

The rate of renal events for OSR is higher, while the rate of endovascular renal events was lower. Our study shows that PR-AAA undergoing OSR may benefit from endovascular repair.

Ultrasound elastography to quantify average percent pressure-normalized strain reduction associated with different aortic endografts in 3D-printed hydrogel phantoms

Objective

Strain has become a viable index for evaluating abdominal aortic aneurysm stability after endovascular aneurysm repair (EVAR). In addition, literature has shown that healthy aortic tissue requires a degree of strain to maintain homeostasis. This has led to the hypothesis that too much strain reduction conferred by a high degree of graft oversizing is detrimental to the aneurysm neck in the seal zone of abdominal aortic aneurysms after EVAR. We investigated this in a laboratory experiment by examining the effects that graft oversizing has on the pressure-normalized strain (ε ρ + ¯ /pulse pressure [PP]) reduction using four different infrarenal EVAR endografts and our ultrasound elastography technique. Approximate graft oversizing percentages were 20% (30 mm phantom-graft combinations), 30% (28 mm phantom-graft combinations), and 50% (24 mm phantom-graft combinations).

Methods

Axisymmetric, 10% by mass polyvinyl alcohol phantoms were connected to a flow simulator. Ultrasound elastography was performed before and after implantation with the four different endografts: (1) 36 mm polyester/stainless steel, (2) 36 mm polyester/electropolished nitinol, (3) 35 mm polytetrafluoroethylene (PTFE)/nitinol, and (4) 36 mm nitinol/polyester/platinum-iridium. Five ultrasound cine loops were taken of each phantom-graft combination. They were analyzed over two different cardiac cycles (end-diastole to end-diastole), yielding a total of 10 maximum mean principal strain (ε ρ + ¯ ) values.ε ρ + ¯ was divided by pulse pressure to yield pressure-normalized strain (ε ρ + ¯ /PP). An analysis of variance was performed for graft comparisons. We calculated the average percentε ρ + ¯ /PP reduction by manufacturer and percent oversizing. These values were used for linear regression analysis.

Results

Results from one-way analysis of variance showed a significant difference inε ρ + ¯ /PP between the empty phantom condition and all oversizing conditions for all graft manufacturers (F(3, 56) = 106.7 [graft A], 132.7 [graft B], 106.5 [graft C], 105.7 [graft D], P < .0001 for grafts A-D). There was a significant difference when comparing the 50% condition with the 30% and 20% conditions across all manufacturers by post hoc analysis (P < .0001). No significant difference was found when comparing the 20% and 30% oversizing conditions for any of the manufacturers or when comparingε ρ + ¯ /PP values across the manufacturers according to percent oversize. Linear regression demonstrated a significant positive correlation between the percent graft oversize and the all-graft average percentε ρ + ¯ /PP reduction (R 2  = 0.84, P < .0001).

Conclusions

This brief report suggests that a 10% increase in graft oversizing leads to an approximate 5.9% reduction inε ρ + ¯ /PP on average. Applied clinically, this increase may result in increased stiffness in axisymmetric vessels after EVAR. Further research is needed to determine if this is clinically significant.

Prophylactic Perigraft Arterial Sac Embolization During EVAR: Minimizing Type II Endoleaks and Improving Sac Regression

BACKGROUND

Type II endoleaks (ELII) are the most common complication following endovascular aneurysm repair (EVAR). Persistent type II endoleaks require continual surveillance and have been shown to increase the risk of Type I and III endoleaks, sac growth, need for intervention, conversion to open or even rupture directly or indirectly. These are often difficult to treat following EVAR and there are limited data regarding the effectiveness of prophylactic treatment of ELII. The aim of this study is to report midterm outcomes of prophylactic perigraft arterial sac embolization (pPASE) performed in patients undergoing EVAR.

METHODS

This is a comparison of two elective cohorts of those undergoing EVAR using the Ovation stent graft with and without prophylactic branch vessel and sac embolization. Patients who underwent pPASE at our institution had data collected in a prospective, IRB approved database. These were compared against the core lab adjudicated data from the Ovation IDE trial. Prophylactic PASE was performed at the time of EVAR with thrombin, contrast and gelfoam if lumbar or mesenteric arteries were patent. Endpoints included freedom from ELII, reintervention, sac growth, all-cause mortality (ACM) and aneurysm-related mortality (ARM).

RESULTS

Thirty-six patients (13.1%) underwent pPASE, while 238 patients (86.9%) had standard EVAR. Median follow-up was 56 months (IQR 33-60). The 4-year freedom from ELII estimates were 84% for the pPASE vs 50.7% for the standard EVAR group (P=0.0002). All aneurysms in the pPASE group remained stable in size or demonstrated regression, whereas aneurysm sac expansion was seen in 10.9% of the standard EVAR group, P=0.03. At 4 years, mean AAA diameter decreased by 11mm (95% CI 8-15) in the pPASE group vs 5mm (95%CI 4-6) for the standard EVAR group, P=0.0005. There were no differences in the 4-year freedom from ACM and ARM. However, the difference in reintervention for ELII trended toward significance (0.0% vs 10.7%, P=0.1). On multivariable analysis, pPASE was associated with a 76% reduction in ELII [aHR(95%CI): 0.24 (0.08-0.65), P=0.005].

CONCLUSION

These results suggest that pPASE in those undergoing EVAR is safe and effective in the prevention of EII and significantly improves sac regression over standard EVAR while minimizing the need for reintervention.

One-year safety and effectiveness of the Alto abdominal stent graft in the ELEVATE IDE trial

OBJECTIVE

This study reports the results of a prospective, multicenter trial designed to evaluate the safety and effectiveness of the polymer based Endologix Alto Stent Graft System in treating abdominal aortic aneurysms (AAAs), with sealing 7 mm below the top of the fabric in aortic neck diameters from 16 to 30 mm.

METHODS

Seventy-five patients were treated with Alto devices between March 2017 and February 2018 in 16 centers in the United States for infrarenal AAAs (max diameter ≥5.0 cm in diameter or size increase by 0.5 cm in 6 months or diameter ≥1.5 times the adjacent normal aorta). Patients were followed for 30 days, 6 months, and 1 year by clinical evaluation and computed tomography and abdominal x-ray imaging. Treatment success was defined as technical success and freedom from AAA enlargement, migration, type I or III endoleak, AAA rupture or surgical conversion, stent graft stenosis, occlusion, kink, thromboembolic events, and stent fracture attributable to the device requiring secondary intervention through 12 months. Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 1 year were analyzed.

RESULTS

The mean patient age was 73 years, with 93% of patients being male. The 30-day major adverse event rate was 5.3%. At 1 year, the primary endpoint was met with a treatment success rate of 96.7%. Through 1-year post-treatment, all-cause mortality was 4.0%. No AAA-related mortality occurred. AAA enlargement was 1.6%, type I endoleak rate was 1.4%, with 100% freedom from type III endoleaks, device migration, device fracture, stent occlusion, or AAA rupture. The device-related secondary intervention rate was 2.7%.

CONCLUSIONS

This prospective study demonstrates the Endologix Alto is safe and effective in treating AAAs with appropriate anatomy at 1 year. The safety endpoint is met by a 5.3% 30-day major adverse event rate, whereas the effectiveness endpoint is met by a treatment success rate of 96%.

"Aortic Balloon-Molding" (ABM) During Ovation Endograft Implantation Expands Graft Use for Hostile Neck Anatomy

BACKGROUND

Challenging aortoiliac anatomy such as short neck and narrow access vessels is responsible for EVAR ineligibility in up to 50% of cases. The Ovation stent-graft helped widen the range of AAAs suitable for EVAR thanks to its low-profile delivery system and polymer-filled sealing rings. However, its advantages are offset by a tight sizing chart that can lead to increased risk of type Ia endoleak or endograft infolding from under or oversizing, respectively. We sought to assess the safety and efficacy of a novel endovascular technique developed to expand the use of the Ovation endograft while avoiding these issues.

METHODS

We conducted a retrospective review of all patients who underwent EVAR with the Ovation endograft at our institution between March 2019 and December 2020. "Aortic Balloon Molding" or ABM is a novel endovascular technique in which the graft is pre-cannulated and a compliant aortic balloon is inflated at the site of the graft's sealing rings during polymer administration. The technique was preferentially performed in patients with hostile neck anatomy (HNA) defined as any or all of angulation>60°, reverse taper configuration, ≥50% circumferential thrombus or calcification. Patients undergoing traditional deployment were compared to those in whom ABM was performed. Endpoints included neck-related adjunctive procedures, technical success, type Ia endoleak at completion angiogram and 1-year freedom from type Ia endoleak and migration.

RESULTS

A total of 43 patients were included in the study, of which, 26 (60.5%) were treated with the ABM technique. Mean follow-up was 7.9±6 months. Patients in the ABM group were more likely to have a reverse taper neck (61.5% vs. 41.2%, P=0.1), to have significant circumferential thrombus or calcium (23.1% vs. 5.9%, P=0.1) and to be treated outside of the Ovation IFU regarding anatomic characteristics (65.4% vs. 41.2%, P=0.1). Technical success was achieved in 100% of cases. However, patients in the ABM group were less likely to require a neck-related adjunctive procedure (7.7% vs. 23.5%, P=0.1). Only one type Ia endoleak was observed at completion angiogram in a patient treated without ABM. At one-year, freedom from type Ia endoleak or migration was 100% for both groups.

CONCLUSIONS

Aortic Balloon Molding proves to be a safe and effective adjunctive technique for the treatment of AAAs with hostile neck anatomy using the Ovation stent-graft. This may allow optimal endograft sizing to achieve adequate seal in complex aortic anatomies. Further research is warranted to evaluate the long-term outcomes of this technique.

Single centre experience with Excluder® stent graft; 17-year outcome

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) has become a mainstay of abdominal aorta aneurysm treatment. Long term follow-up on specific stent grafts is needed.

PATIENTS AND METHODS

This study included 123 patients (104 men; mean age 73.0 years, range 51-89) with abdominal aorta aneurysm, treated with Excluder^® stent graft between October 2002 and June 2008. Periprocedural and follow-up data were retrieved by reviewing the records of our institution, while time and cause of death were retrieved from the National Institute of Public Health. If an abdominal aortic aneurysm rupture was listed as the cause of death, records were retrieved from the institution that issued the death certificate. Our primary goal was to assess the primary technical success rate, type 1 and type 2 endoleak, reintervention free survival, 30-day mortality, the overall survival and aneurysm rupture-free survival.

RESULTS

The median follow-up was 9.7 years (interquartile range, 4.6-13.8). The primary technical success was 98.4% and the 30-day mortality accounted for 0.8%. Secondary procedures were performed in 29 (23.6%) patients during the follow-up period. The one-, five-, ten-, fifteen- and seventeen-year overall survival accounted for 94.3%, 74.0%, 47.2%, 35.8% and 35.8%, while the aneurysm-related survival was 98.4%, 96.3%, 92.6%, 92.6%, 92.6%. In seven (5.7%) patients, abdominal aortic rupture was found as the primary cause of death during follow-up.

CONCLUSIONS

Our data showed that EVAR with Excluder^® stent graft offers good long-term results. More than 75% of patients can be treated completely percutaneously. Late ruptures do occur in the first ten years, raising awareness about regular medical controls.

The Correlation Of Aortic Neck Length To Late Outcomes Following EVAR with the Ovation Stent Graft

BACKGROUND

Endovascular aneurysm repair (EVAR) performed outside manufacturers' instructions for use (IFU) due to short aortic neck for the treatment of abdominal aortic aneurysm (AAA) is associated with unfavorable outcomes. Newer endografts now have an indication for shorter neck aneurysms that previous endografts do not, but this cohort has yet to be evaluated individually. The aim of this study is to evaluate 5-year outcomes after EVAR in patients with short aortic necks (<10mm) using the Ovation stent graft.

METHODS

The study comprised 238 patients who underwent EVAR as part of the prospective international multicenter Ovation stent graft trials. The main inclusion criteria were AAA diameter ≥ 5cm, proximal parallel neck length ≥7mm, neck angulation ≤60° and bilateral iliac fixation length ≥10 mm. A clinical events committee adjudicated adverse events through 1 year, an independent imaging core laboratory analyzed imaging through 5 years and a data safety and monitoring board provided study oversight. Patients were divided into short neck (<10mm) and standard neck (≥10mm) groups. Endpoints included long-term survival, freedom from aneurysm-related mortality (ARM), freedom from type Ia Endoleak and freedom from reintervention.

RESULTS

Patients were predominantly male (81%) with a mean age of 73±8 years. Median follow-up time was 58 months (IQR 36-60). Out of 238 patients, 41 (17.2%) had a proximal neck length <10mm and would be considered outside the IFU with other stent grafts. Baseline characteristics were relatively similar between the two groups. The 5-year overall survival estimates were 77.8% for the standard neck group compared to 59.5% for the short neck group (P= .03) (Figure1). There were no differences in the 5-year freedom from ARM (99.2% vs. 100%, P= .7), freedom from type Ia Endoleak (96.3% vs. 96.3%, P= .8) and freedom from reintervention (77.9% vs. 79.7%, P= .7) between the standard and short neck groups, respectively. After adjusting for age and other potential confounders, short proximal neck was associated with a 2-fold increase in 5-year all-cause mortality [aHR(95%CI): 2(1.02-3.8), P= .04].

CONCLUSION

The Ovation endograft performed well in short AAA neck with no difference in 5-year type Ia Endoleak, reintervention and ARM rates. However, short proximal neck was independently associated with a two-fold increase in the risk of all-cause mortality at five years. These findings confirm the prior literature on the association of hostile neck anatomy with late mortality following EVAR.

Profile of the Ovation ALTO abdominal stent graft for the treatment of abdominal aortic aneurysms: overview of its safety and efficacy

INTRODUCTION

The Ovation ALTO is the next generation aortic stent graft from Endologix for the treatment of infra-renal abdominal aortic aneurysms. The device uses polymer-injected rings to create a proximal seal at the aneurysm neck.

AREAS COVERED

Results from the first clinical study of the ALTO graft are analyzed and the potential benefits of the graft in minimizing post-treatment aneurysmal neck dilation discussed. The implications of the ALTO's Instructions-For-Use (IFU) and low-profile delivery system are also reviewed.

EXPERT OPINION

The re-positioning of the sealing rings higher on the graft and an integrated compliant balloon are the most significant improvements on the Ovation iX, facilitating accurate placement of the proximal sealing ring and prompt balloon dilation of the polymer rings. The expansion the IFU to include neck lengths of ≥7 mm will mean more patients are eligible for infra-renal EVAR within IFU with the ALTO device. The published data on the device to date is limited. With over 1000 implants worldwide we would hope for more published data to become available. If this demonstrates similar mid-term results to that seen with the Ovation iX in arguably more hostile neck anatomy, then the Ovation ALTO is likely to be more widely used.

Polymer based endografts have improved rates of proximal aortic neck dilatation and migration

BACKGROUND

Proximal aortic neck dilatation (PND) affects a considerable proportion of patients undergoing endovascular aneurysm repair (EVAR) and is associated with increased rates of type I endoleak (EL1), migration, and reinterventions. Although there are numerous studies investigating PND following the placement of endografts that utilize self-expanding stent (SES) technology, there are few reports for patients treated with endografts that utilize polymer-filled rings. The purpose of this study is to examine PND and graft migration after EVAR with the Ovation stent graft.

METHODS

The study comprised patients who underwent EVAR as part of the prospective, international, multicenter Ovation stent graft trial. A clinical events committee adjudicated adverse events through 1 year, an independent imaging core laboratory analyzed imaging through 5 years, and a data safety and monitoring board provided study oversight. Neck diameter was measured at the level of the lowest renal artery. PND was defined as neck enlargement of 3 mm or more. Graft migration was defined as distal movement >10 mm or movement ≤10 mm when resulting in secondary intervention.

RESULTS

A total of 238 patients received this device during the study period. Patients were predominantly male (81%), with a mean age of 73 ± 8 years. Median follow-up was 58 months (IQR 36-60). Almost half the patients (110 patients, 46%) had challenging anatomy; defined as outside the instructions for use (IFU) with other commercially available stent grafts. 41 patients (17.2%) had a proximal neck length <10 mm and 93 (39%) had a minimum access vessel diameter <6 mm. The technical success rate was 100%. The 1-, 3- and 5-year overall survival rates were 96.6%, 86.2% and 74.9%, respectively. The immediate postoperative proximal neck diameter ranged from 16 mm to 31 mm with a mean of 22.4 ± 3 mm. During follow-up, ten patients (4.2%) developed PND. Freedom from PND estimates at 1, 3 and 5 years were 97.7%, 96%, and 93.6%, respectively. None of the patients developed endograft migration.

CONCLUSIONS

The use of the Ovation stent graft was associated with low rates of PND despite challenging neck anatomy in 17% of patients. No graft migration was observed. The design of this endograft may explain its superiority to SES in preventing neck dilatation and migration even in patients with challenging neck anatomy. This is important, as we continue to see significant late failures of EVAR due to proximal neck degeneration.

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

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

Endovascular aortic repair in patients with challenging anatomies: the EXTREME study

AIMS

The aim of this study was to report the 30-day technical and clinical success with endovascular repair using the ultra-low-profile Ovation stent graft in patients judged to be outside the instructions for use (IFU) for conventional endografts, while amenable to treatment within the IFU for Ovation.

METHODS AND RESULTS

One hundred and twenty-two patients (78.65±7.67 years; 111 male) were enrolled. Patients were evaluated as being outside the IFU for standard endografts because of the absence of a suitable proximal aortic neck in 109 cases (89.3%), of inadequate access vessels in 13 (10.7%), or both in 111 (90.9%). Mean aneurysm (abdominal aortic aneurysm [AAA]) diameter was 52.96±10.1 mm; mean aortic neck length was 7.75±6.05 mm. Technical success (98.4%) was achieved in all but two patients due to a type Ia endoleak. At completion angiography, 15 (12.3%) patients presented a type II endoleak. All patients underwent 30-day follow-up. Primary clinical success at one month was 96.8%, assisted clinical success 98.4%. There were no type I endoleaks, while 12 (9.8%) type II endoleaks were still evident, in the absence of sac expansions. Two patients (1.6%) presented an asymptomatic limb occlusion.

CONCLUSIONS

Our experience suggests that, in a selected population of patients with challenging anatomy outside the IFU for conventional endografts, endovascular aneurysm repair (EVAR) using the Ovation stent graft can be performed safely with satisfactory immediate outcomes.

Epidemiology of abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) disease remains a major source of morbidity in developed countries and can progress to life-threatening rupture if left untreated, with exceedingly high mortality. The goal of AAA management is to identify and electively repair AAAs before rupture. AAA disease burden and outcomes have improved over time with declining tobacco use and advancements in care across patients' disease course. The introduction of endovascular AAA repair, in particular, has allowed for elective AAA repair in patients previously considered too high risk for open surgery and has contributed to lower rates of AAA rupture over time. However, these improved outcomes are not universally experienced, and disparities continue to exist in the detection, treatment, and outcomes of AAA by sex, race, and ethnicity. Mitigating these disparities requires enhanced, focused efforts at preventing disease, promoting health, and delivering appropriate care among an increasingly diverse patient population.

An update on the ovation abdominal stent graft for the treatment of abdominal aortic aneurysms: current evidence and future perspectives

Introduction: The Ovation stent-graft has presented satisfactory mid-term results in the management of abdominal aortic aneurysms (AAA). Its unique design with uncoupling of fixation and sealing and the lowest profile in the market has expanded the treatment in AAA with challenging neck anatomies and, especially, in the females presenting mostly with narrow iliac access vessels. Morever, a new design modification, the Ovation Alto was recently introduced in the Market, while certain off-label uses of the Ovation in treating either juxtarenal- or short-necked AAA have been proposed. Areas covered: Aim of this article was to present the current articles with the long-term results of the Ovation endograft and discuss the new developments and modifications in its use. Expert commentary: the Ovation stent-graft exhibits very satisfactory clinical long-term results in AAA treated within the instructions-for-use, expands significantly the treatment of AAA in females and overcomes reliably challenging anatomical issues of the infrarenal neck that would render these cases ineligible for treatment with any other endograft. Εxperience with the specific, unique technical features of Ovation as well as careful selection of patients and meticulous preoperative study of the AAA anatomy are key-elements to the successful performance of this endograft.

Physician-modified fenestrated endovascular repair of type 1A endoleaks from polymer-based low-profile endografts

PURPOSE

There have been increasing number of endovascular aortic aneurysm repair performed in hostile necks using newer generation technology including polymer-based proximal sealing devices such as the Ovation system. Unique design features of the device can pose challenges during endovascular salvage of type 1A endoleak. We describe two cases of successful application of physician-modified fenestrated endografting, in order to repair type 1A endoleaks following endovascular aortic aneurysm repair with ovation system.

TECHNIQUE

In both cases, multi-fenestrated endografts were custom-modified using preloaded wire technique on Cook Zenith Alpha thoracic stent grafts at the back table. Under general anesthesia, left brachial cut down and a single percutaneous femoral access were performed. Staggered deployment of fenestrated endograft, accompanied by sequential catheterization of target vessels, facilitated correct alignment of fenestrated endograft. Infolding of fenestrated endograft inside the Ovation main body resulted in leg claudication, and repaired with balloon expandable covered tent. Prophylactic deployment of balloon expandable covered stent was performed in the second case. Both cases showed resolution of type 1A endoleak.

CONCLUSION

Fenestrated endovascular repair is feasible for proximal failure of Ovation endografts. Careful planning and advanced skill set in complex endovascular aortic repair are required, as well as detailed knowledge of the failed endografts.

Five-year results of the INSPIRATION study for the INCRAFT low-profile endovascular aortic stent graft system

OBJECTIVE

We present the 5-year results of a prospective regulatory study of the INCRAFT device, a low-profile endovascular stent graft system for repair of abdominal aortic aneurysms.

METHODS

This was an open-label prospective nonrandomized single-arm study enrolling in centers in the United States and Japan. The primary effectiveness outcome was successful aneurysm treatment and the primary safety outcome was the incidence of major adverse events at 30 days after the procedure. Major long-term outcomes were mortality, reintervention, adverse limb outcomes, and suprarenal stent fracture.

RESULTS

One hundred and ninety patients (mean age, 73.8 ± 7.6 years; 90% male; 69% white and 30% Asian) were enrolled from 32 centers throughout the United States and Japan. Minimal access vessel size was less than 7 mm on both sides in 43.9% of the study cohort. Thirty-day major adverse events occurred in 3.2% of patients (6/190). Periprocedural technical success was 94.1% (176/187). Successful aneurysm treatment was 100% at 30 days and 87.9% at 1 year. Two patients required open conversion for thromboembolic complications, 3 developed new type I or III endoleaks, and 7 experienced graft or limb occlusion. Freedom from graft occlusion was 96 ± 2% at 1 year and 94 ± 2% at 5 years. Freedom from stent fracture was 97 ± 1% at 1 year and 87 ± 3% at 5 years. Freedom from aneurysm-related mortality was 99 ± 1% at 1 and 5 years.

CONCLUSIONS

This study demonstrates good efficacy and safety and a very low rate of aneurysm related deaths with the INCRAFT device in a population with a high proportion of challenging anatomy.

Current assessment and management of endoleaks after advanced EVAR: new devices, new endoleaks?

INTRODUCTION

In recent years there has been an increasing application of advanced EVAR techniques to tackle complex clinical and anatomical scenarios. In a bid to overcome the limitations of the traditional stent-grafts, newer EVAR endografts and techniques have been developed and introduced into clinical practice, permitting endovascular management of difficult infrarenal, juxta-renal and thoracoabdominal aneurysms for which previously there was no endovascular solution. As a consequence, we are now confronted with unique patterns of endoleak requiring customized clinical-radiological assessment and treatment. Despite the increasing body of evidence regarding new EVAR techniques and related endoleaks, current guidelines do not specifically address these issues.

OBJECTIVES

Our review aims to assess risk factors, development, and management strategies of these endoleaks, in the most recent infrarenal EVAR devices and in more complex fenestrated EVAR (FEVAR) and Chimney EVAR (Ch-EVAR).

EXPERT OPINION

Most new devices have demonstrated types of endoleaks that need specific imaging and treatment, as in EVAS, FEVAR, and ChEVAR. Knowledge of specific stent-graft characteristics and the nature of endoleaks associated with the various procedures facilitates the application of relevant useful imaging. In addition, it should aid development of a customized and practically relevant approach to patient management during intervention and follow-up.

Reporting standards for endovascular aortic repair of aneurysms involving the renal-mesenteric arteries

Endovascular aortic aneurysm repair of complex aortic aneurysms requires incorporation of side branches using specially designed aortic stent grafts with fenestrations, directional branches, or parallel stent grafts. These techniques have been increasingly used and reported in the literature. The purpose of this document is to clarify and to update terminology, classification systems, measurement techniques, and end point definitions that are recommended for reports dealing with endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms involving the renal and mesenteric arteries.

Similar 5-year outcomes between female and male patients undergoing elective endovascular abdominal aortic aneurysm repair with the Ovation stent graft

OBJECTIVE

Female patients undergoing endovascular aneurysm repair (EVAR) for infrarenal abdominal aortic aneurysms present with more challenging anatomy and historically have worse outcomes compared with men. The Ovation Abdominal Stent Graft platform (Endologix, Irving, Calif) contains a polymer-filled proximal sealing ring and has a low-profile delivery system, potentially beneficial in female patients. We therefore investigated differences in long-term outcomes between men and women treated with this device.

METHODS

We used data collected prospectively in the Effectiveness of Custom Seal with Ovation: Review of the Evidence (ENCORE) database, comprising five trials and the European Post-Market Registry. Anatomic characteristics of the proximal aneurysm neck and iliac arteries were compared between male and female patients. Outcomes were 5-year freedom from type IA and type I/III endoleaks, abdominal aortic aneurysm-related reinterventions, and overall survival. We used Kaplan-Meier analysis to estimate survival proportions and tested univariate differences in survival using log-rank tests. Cox proportional hazards modeling was used to adjust for baseline differences.

RESULTS

We identified 1045 (81%) male and 251 (19%) female patients undergoing EVAR. Female patients were older (mean age, 75 ± 8.4 years vs 73 ± 8.1 years; P < .006). Aneurysm diameter (52 ± 7.5 mm vs 55 ± 9.2 mm; P < .001) and proximal neck diameter (21 ± 3.3 mm vs 23 ± 2.9 mm; P < .001) were smaller in female patients, but adjusted for body surface area, female patients had relatively larger aneurysms and aneurysm necks. Furthermore, female patients presented with shorter proximal necks, smaller iliac artery diameters, more angulated necks, and higher rates of reverse-tapered necks. Five-year freedom from type IA endoleak was similar between men and women (97% vs 96%; P = .38), as was freedom from type I/III endoleaks (91% vs 94%; P = .37) and reinterventions (91% vs 93%; P = .67). Five-year survival was 81% for female patients, similar to the 79% in male patients (P = .55), with one aneurysm-related death in female patients (0.4%) and five in male patients (0.8%; P = .76). Risk-adjusted analyses showed no association between sex and type IA endoleak (hazard ratio [HR], 1.4; 95% confidence interval [CI], 0.6-3.1; P = .41), type I/III endoleak (HR, 1.4; 95% CI, 0.7-2.8; P = .33), reintervention (HR, 1.0; 95% CI, 0.6-2.0; P = .77), and overall mortality (HR, 0.7; 95% CI, 0.4-1.1; P = .14).

CONCLUSIONS

Female patients undergoing EVAR with the Ovation platform presented with substantially more adverse proximal neck characteristics. Despite these differences, 5-year freedom from endoleaks and overall survival did not differ between sexes.

Polymer leak with the Ovation Abdominal Stent Graft System: Early recognition and treatment

Objective

Endovascular aneurysm repair can be performed using multiple commercially available stent graft systems, each with their own unique design features and potential complications. This study evaluated the incidence, risk factors and outcomes of patients who developed an anaphylactic reaction following systemic exposure to the polymer used with the Ovation Abdominal Stent Graft System (Endologix Inc., Irvine, CA).

Methods

We reviewed all reports related to polymer leak with the device received by the manufacturer (formerly known as TriVascular, Santa Rosa, CA). Patients who developed an anaphylactic or hypersensitivity reaction were evaluated for root cause. The manufacturer was contacted to assemble all available data and outcomes related to the case reports.

Results

Between November 2009 and August 2016, polymer leak was reported in 26 patients (mean age, 77, range 61–100 years) from approximately 10,000 device implants (reported incidence, 0.26%). Symptoms occurred in 24 patients, with hypotension being the primary symptom. Treatment was in accordance for an anaphylactic reaction. There were no deaths, and the aneurysm sac remained unexcluded in three patients at the end of the case. Of these, one patient underwent successful endovascular re-intervention, one was converted to open surgical repair and one patient continued to be monitored. Factors that appear to contribute to the risk of polymer leak include initial manufacturing process for the device, excessive graft manipulation, early ballooning prior to complete polymer cure and lower body temperature, which can slow the polymer cure rate.

Conclusion

Although polymer leak and anaphylaxis appear to be an infrequent event associated with use of the Ovation graft, awareness of this complication and prompt recognition can allow for timely treatment. Returning the patient to hemodynamic stability can allow for completion of the procedure and successful exclusion of the aneurysm sac.

Five-year results of endovascular abdominal aortic aneurysm repair with the Ovation abdominal stent graft

OBJECTIVE

Endovascular abdominal aortic aneurysm repair (EVAR) has been rigorously compared with open repair for the treatment of abdominal aortic aneurysms in randomized trials and observational studies, but a comparison of individual devices is lacking, and single-device registries and trials are limited by small sample size. Here we report a descriptive analysis of the Effectiveness of Custom Seal with Ovation: Review of the Evidence (ENCORE) database, pooled results of multiple studies evaluating the midterm results of EVAR with the Ovation Abdominal Stent Graft Platform.

METHODS

This is a retrospective analysis of the ENCORE database, a cohort of patients undergoing EVAR with the Ovation platform composed of pooled, prospectively collected data from 1296 patients from five clinical trials and the prospectively maintained European Union Post-Market Registry. The primary outcomes were 5-year rates of type IA and type I or III endoleak. Secondary outcomes included were 30-day mortality, 30-day major adverse event, technical success (successful deployment of the aortic body and iliac limbs), as well as 5-year survival, and freedom from aneurysm-related mortality, type II endoleak, device-related intervention, aneurysm rupture, sac expansion, and conversion to open repair.

RESULTS

A total of 1296 patients were included in the analysis. The average age was 73 ± 8 years and 81% of patients were male. Fifty percent of patients had complex aortic anatomy, (neck length <10 mm, neck diameter >28 mm, neck angle >60°, reverse neck taper >10%, distal common iliac artery diameter <10 mm, or external iliac artery diameter <6 mm). Technical success was 99.7%. Thirty-day mortality was 0.3%, 30-day rate of major adverse event was 1.6%, and polymer leak rate was 0.2%. Freedom from type IA endoleak at 1, 3, and 5 years was 97.6%, 97.1%, and 95.8%, respectively; type I or III endoleak at 1, 3, and 5 years was 96.9%, 95.7%, and 94.0%, respectively. Freedom from device-related reintervention at 1, 3, and 5 years was 96.2%, 94.4%, and 92.4% and primary freedom from sac expansion was 97.0% at 1 year, 90.3% at 3 years, and 84.9% at 5 years. Freedom from all-cause mortality and aneurysm-related mortality at 5 years were 78.9% and 99.3%, respectively.

CONCLUSIONS

This analysis of the ENCORE database demonstrates that EVAR with the Ovation platform has favorable midterm durability evidenced by successful aneurysm exclusion and 5-year freedom from aneurysm-related mortality.

[New developements in endovascular infrarenal aortic aneurysm treatment]

CLINICAL/METHODICAL ISSUE

New technical developments in endovascular aortic repair (EVAR) have broadened the range of patients eligible for minimally invasive aneurysm treatment. Optimization of delivery sheaths and catheters by considerable downsizing of diameters, increase of pushability and stability combined with flexibility are important parameters.

PERFORMANCE

Especially patients characterized by small and tortuous iliac access vessels can nowadays be treated by EVAR. Ease and effectiveness of applicability guarantee safety and quality improvement, which results in better treatment of patients. Progress in stent-graft design with integrated options for repositioning, active positioning and aneurysm sealing facilitate treatment of angulated vessel segments or hitherto unsuitable sealing zones.

PRACTICAL RECOMMENDATIONS

Interventionalists have to be familiar with all available stent-graft materials and techniques. Profound knowledge helps to choose the best material for a patient's individual anatomy, confident application and long-term satisfactory results.

A clinical update on the mid-term clinical performance of the Ovation endograft

INTRODUCTION

The Ovation stent-graft uncouples the steps of fixation and sealing via a pair of polymer-filled inflatable rings. Apart from the well-documented early results, newer data emerged for mid-term results of Ovation and are presented in this review.

AREAS COVERED

Aim of this article was to report all current studies with the mid-term results of the particular endograft, the incidence of complications and failure, and discuss their management.

EXPERT COMMENTARY

The Ovation stent-graft exhibits very satisfactory clinical mid-term results in abdominal aortic aneurysms treated within the instructions-for-use. It can also have a very promising role in challenging neck anatomies with conical shape and presence of thrombus or calcification. However, this should be not considered a panacea and long-term results are needed to validate this intriguing aspect.

Type 2 Endoleak Incidence and Fate After Endovascular Aneurysms Repair in a Multicentric Series: Different Results with Different Devices?

BACKGROUND

The aim of this work is describing incidence and fate of type 2 endoleaks (T2ELs) in a multicentric cohort of patients treated by endovascular aneurysms repair using the Ovation device (Endologix) and comparing them with a group treated using the Excluder (W. L. Gore & Associates).

METHODS

This is a retrospective study conducted on 261 patients treated using the Ovation device and 203 using the Excluder. Outcomes were intraprocedural, 30-day, 12-month, and mean time follow-up T2EL incidence and related reinterventions. Patent inferior mesenteric artery (IMA), ≥3 lumbar arteries (LAs), intrasac thrombus volume, the mean diameter of common and external iliac arteries, external iliac artery stenosis (>70%), diameter ≤5 mm, iliac tortuosity ratio ≤0.5, thrombosis, and calcification were noted and considered as potentially influencing outcomes.

RESULTS

Patients of the Ovation group presented significantly more thrombosed, calcified, and tortuous iliac vessels than those in the Excluder group. No significant differences were noted in sac thrombosis, IMA, and LA patency. At completion angiography, T2EL was evident in 57 Ovation and 46 Excluder patients (P = 0.832). At 1 month, it was evident in 33 Ovation group and 28 Excluder group patients (P = 0.726). At 12-month and mean time (30.14 months) follow-up, no differences were evident between the 2 groups (P = 0.940 and 0.951, respectively). The log-rank test showed that the rate of T2EL-related reintervention was not different between the 2 groups (P = 0.46). Regarding anatomical characteristics, a statistically significant difference was not observed between patients presenting or not with T2EL (P > 0.05).

CONCLUSIONS

Data showed no significant differences in terms of T2EL incidence between the 2 study groups. None of preoperative anatomical features were found to be significantly associated with the appearance of T2EL.

Nellix Endobag rupture associated with a fatal outcome

Endovascular treatment of a type IA endoleak was conducted using a Nellix chimney graft technique for an expanding abdominal aortic aneurysm in an 84-year-old man. During the procedure, a polymer leak occurred from one of the endobags. Postoperatively, the patient developed hemodynamic instability and a swollen leg on the side of the leaking endobag, resulting in a fatal outcome.

Comparing polymer-filled versus self-expanding endografts in Chinese patients

INTRODUCTION

We performed a single-center nonrandomized study on patients who underwent endovascular aneurysm repair using polymer-filled or other self-expanding endografts.

METHODS

Consecutive patients with asymptomatic infrarenal abdominal aortic aneurysms who underwent endovascular repair were retrospectively reviewed. They were divided into a polymer-filled ( n = 20) or self-expanding group ( n = 42). Baseline characteristics, operative mortality and morbidity, and follow-up data were compared.

RESULTS

Aneurysm diameter, neck and iliac morphologies did not differ between the two groups. Technical success was 100%. The 30-day mortality was 0% and 2.4% in the polymer-filled and self-expanding group, respectively. At a mean follow-up of 17 months, the changes in sac size were -2.1 mm and -5.1 mm ( p = 0.144) at one year, and -3.5 mm and -7.7 mm ( p = 0.287) at 2 years in the polymer-filled and self-expanding group, respectively. The polymer-filled group had 7 (35%) type II endoleaks, and the self-expanding group had 1 (2.4%) type Ia and 13 (31%) type II endoleaks. Neck diameter remained stable in the polymer-filled stent-grafts whereas there was progressive neck degeneration in the self-expanding group. The rates of reintervention and overall survival were similar in both groups. The presence of an endoleak was the only predictor of non-regression of the aneurysm (odds ratio = 17.00, 95% confidence interval: 4.46-64.88, p < 0.001).

CONCLUSION

Polymer-filled endografts had similar safety, effectiveness, and durability to other self-expanding endografts. The major advantage is the small iliofemoral access. They also have the potential long-term benefit of a more stable neck.

Global Post-Market Clinical Follow-up of the Treovance Stent-Graft for Endovascular Aneurysm Repair: One-Year Results From the RATIONALE Registry

PURPOSE:

To evaluate the safety and performance of the Treovance stent-graft.

METHODS:

The global, multicenter RATIONALE registry ( ClinicalTrials.gov; identifier NCT03449875) prospectively enrolled 202 patients (mean age 73.0±7.8 years; 187 men) with abdominal aortic aneurysms (AAA) suitable for endovascular aneurysm repair (EVAR) using the Treovance. The composite primary safety endpoint was site-reported all-cause mortality and major morbidity. The primary efficacy outcome was clinical success. Further outcomes evaluated included technical success; stent-graft migration, patency, and integrity; endoleak; and aneurysm size changes.

RESULTS:

Technical success was 96% (194/202); 8 patients had unresolved type I endoleaks at the end of the procedure. There was no 30-day mortality and 1% major morbidity (1 myocardial infarction and 1 bowel ischemia). Clinical success at 1 year was confirmed in 194 (96%) patients; 6 of 8 patients had new/persistent endoleaks and 2 had aneurysm expansion without identified endoleak. A total of 8 (4%) reinterventions were required during the mean 13.7±3.1 months of follow-up (median 12.8). At 1 year, the Kaplan-Meier estimate for freedom from reintervention was 95.6% (95% CI 91.4% to 97.8%). Other estimates were 95.5% (95% CI 91.7% to 97.6%) for freedom from endoleak type I/III and 97.4% (95% CI 94.2% to 98.9%) for freedom from aneurysm expansion. Thirteen (6.4%) patients died; no death was aneurysm related.

CONCLUSION:

The RATIONALE registry showed favorable safety and clinical performance of the Treovance stent-graft for the treatment of infrarenal AAAs in a real-world setting.

Initial Clinical Experience Using the Low-Profile Altura Endograft System With Double D-Shaped Proximal Stents for Endovascular Aneurysm Repair

Purpose: To report the initial clinical results of endovascular aneurysm repair (EVAR) using the low-profile (14-F) Altura Endograft System, which features a double “D-shaped” stent design with suprarenal fixation and modular iliac components that are deployed from distal to proximal. Methods: From 2011 to 2015, 90 patients (mean age 72.8±8.3 years; 79 men) with abdominal aortic aneurysm (AAA; mean diameter 53.8±5.7 mm) were treated at 10 clinical sites in 2 prospective, controlled clinical studies using the Altura endograft. Outcomes evaluated included mortality, major adverse events (MAEs: all-cause death, stroke, paraplegia, myocardial infarction, respiratory failure, bowel ischemia, and blood loss ≥1000 mL), and clinical success (freedom from procedure-related death, type I/III endoleak, migration, thrombosis, and reintervention). Results: Endografts were successfully implanted in 89 (99%) patients; the single failure was due to delivery system malfunction before insertion in the early-generation device. One (1%) patient died and 4 patients underwent reinterventions (1 type I endoleak, 2 iliac limb stenoses, and 1 endograft occlusion) within the first 30 days. During a median follow-up of 12.5 months (range 11.5–50.9), there were no aneurysm ruptures, surgical conversions, or AAA-related deaths. The cumulative MAE rates were 3% (3/89) at 6 months and 7% (6/89) at 1 year. Two patients underwent coil embolization of type II endoleaks at 6.5 months and 2.2 years, respectively. Clinical success was 94% (84/89) at 30 days, 98% (85/87) at 6 months, and 99% (82/83) at 1 year. Conclusion: Early results suggest that properly selected AAA patients can be safely treated using the Altura Endograft System with favorable midterm outcome. Thus, further clinical investigation is warranted to evaluate the role of this device in the treatment of AAA.

Early outcomes with a single-sided access endovascular stent

OBJECTIVE

The objective of this study was to report the 1-year follow-up study results of the new Horizon stent graft (Endospan, Herzliya, Israel) from two different prospective consecutive trials. The Horizon abdominal aortic aneurysm stent graft system is a 14F profile system requiring only a single access site. It consists of three modules, introduced separately: base limb (iliac to iliac limb); distal aortic limb; and proximal aortic limb with a bare suprarenal crown and active fixation.

METHODS

Data from the first in man (FIM) clinical study with 10 patients enrolled and the pivotal study with 30 patients were analyzed. Outcomes measured were freedom from major adverse events (MAEs) including all-cause mortality, myocardial infarction, renal failure, respiratory failure, paraplegia, stroke, bowel ischemia, and procedural blood loss ≥1000 mL. Performance end points included successful delivery and deployment of the device, freedom from aneurysm growth ≥5 mm, type I or type III endoleak, stent graft occlusion, conversion to open surgery, rupture, and stent graft migration.

RESULTS

In the FIM study, one conversion to open surgery with >1000 mL of blood loss was registered perioperatively. In the pivotal study, no perioperative MAE was registered. Overall, at 1-year follow-up, two deaths and one aneurysm growth unrelated to endoleak were registered.

CONCLUSIONS

The results of both the FIM and pivotal studies demonstrated that 39 of 40 procedures were successful for delivery and deployment of the Horizon stent graft. No MAE was registered during the follow-up. The primary safety and performance end points were met in both studies.

Polymer Embolization and Anaphylactic Reaction during Implantation of an Ovation Stent Graft for Abdominal Aortic Aneurysm Exclusion

During implantation of an Ovation endograft for abdominal aortic aneurysm (AAA) correction, a patient experienced anaphylactic reaction after polymer leakage outside the device circuit. Procedure was completed after hemodynamic stabilization. Since postoperative day 2, patient complained of loss of legs strength. Medullar injury was excluded by electromyography test, and the clinical signs attributed to muscular necrosis and peripheral nerve involvement after arterial embolization. Furthermore, immediately after surgery, a wide erythematous area appeared in the lumbar region. During the next few days, the lesion developed from extensive blisters and necrosis to deep loss of substance. The wound needed to be medicated 2 or 3 times per week. One year after surgery, the patient still needs crutches for deambulation, and the back injury is currently under treatment. In conclusion, surgeons performing aortic endovascular repair with the Ovation endograft, as well as anesthesiologists participating in the procedure, should be aware of the possibility of embolization and ready to promptly treat possible complications.

Extrinsic Compression of the Ovation Stent-Graft Following Glue Embolization for Type II Endoleak: An Unusual Complication

PURPOSE

To describe a case of extrinsic compression of the Ovation stent-graft following glue embolization for type II endoleak.

CASE REPORT

A 75-year-old man with a past history of ischemic heart disease and endovascular aneurysm repair with an Ovation stent-graft was admitted for treatment of type II endoleaks from the right L2 and left L4 lumbar arteries with egress via the inferior mesenteric and right L4 lumbar arteries, respectively. Successful embolization was performed via a translumbar sac puncture with a combination of coils and histoacryl glue. On final angiography severe lumen narrowing of the unsupported portion of the Ovation stent-graft was seen owing to extrinsic compression by the glue. This was successfully salvaged with percutaneous transarterial kissing balloon angioplasty.

CONCLUSION

Aortic lumen narrowing caused by extrinsic compression of an Ovation stent-graft following glue embolization of type II endoleak is an unusual and potentially problematic complication.

Perioperative Outcomes From the Prospective Multicenter Least Invasive Fast-Track EVAR (LIFE) Registry

Purpose: To determine the feasibility, perioperative resource utilization, and safety of a fast-track endovascular aneurysm repair (EVAR) protocol in well-selected patients. Methods: Between October 2014 and May 2016, the LIFE (Least Invasive Fast-track EVAR) registry ( ClinicalTrials.gov identifier NCT02224794) enrolled 250 patients (mean age 73±8 years; 208 men) in a fast-track EVAR protocol comprised of bilateral percutaneous access using the 14-F Ovation stent-graft, no general anesthesia, no intensive care unit (ICU) admission, and next-day discharge. The primary endpoint was major adverse events (MAE) through 30 days. The target performance goal for the MAE endpoint was 10.4%. Results: Vascular access, stent-graft delivery, and stent-graft deployment success were 100%. A total of 216 (86%) patients completed all elements of the fast-track EVAR protocol. Completion of individual elements was 98% for general anesthesia avoidance, 97% for bilateral percutaneous access, 96% for ICU avoidance, and 92% for next-day discharge. Perioperative outcomes included mean procedure time of 88 minutes, median blood loss of 50 mL, early oral nutrition (median 6 hours), early mobilization (median 8 hours), and short hospitalization (median 26 hours). Fast-track EVAR completers had shorter procedure time (p<0.001), less blood loss (p=0.04), faster return to oral nutrition (p<0.001) and ambulation (p<0.01), and shorter hospital stay (p<0.001). With 241 (96%) of the 250 patients returning for the 30-day follow-up, the MAE incidence was 0.4% (90% CI 0.1% to 1.8%), significantly less than the 10.4% performance goal (p<0.001). No aneurysm rupture, conversion to surgery, or aneurysm-related secondary procedure was reported. There were no type III endoleaks and 1 (0.4%) type I endoleak. Iliac limb occlusion was identified in 2 (0.8%) patients. The 30-day hospital readmission rate was 1.6% overall. Conclusion: A fast-track EVAR protocol was feasible in well-selected patients and resulted in efficient perioperative resource utilization with excellent safety and effectiveness.

Atypical Endoleak Associated With Inadvertent Cannulation of the Ipsilateral Gate in an Ovation Trimodular Stent-Graft

We report on a 54-year-old man who presented with an atypical, proximal, intraoperative endoleak after endovascular aortic repair with an Ovation endograft for a 65-mm-diameter abdominal aortic aneurysm. The endografting was complicated by inadvertent bilateral iliac limb insertion into the right gate without cannulation of the left gate. The endoleak was treated by brachial approach: Through the open left gate, the outflow inferior mesenteric artery was coil embolized and the inflow left gate was closed with an Amplatzer plug. Follow-up computed tomography over 3 years showed absence of any endoleak and a stable diameter of the excluded abdominal aortic aneurysm.

Preliminary Dual-Center Experience with the Bolton Treovance Endograft

PURPOSE

To present the performance and safety of the Treovance stent graft for endovascular aortic aneurysm repair in a "real-world" patient cohort.

METHODS

Patients from 2 centers, deemed unfit for open repair, were electively treated with the Treovance endograft. Clinical preoperative, operative, and up to 1-year postoperative follow-up data of patients were retrospectively analyzed.

RESULTS

This study included 46 patients with abdominal aortic aneurysm (44 male), mean age of 78 years ± 8 standard deviation (SD; range: 58-93 years). All met the manufacturer's recommended anatomical requirements: average maximum sac diameter 63 mm ± 10 SD (range: 52-86 mm), proximal neck length 29 mm ± 12 SD (range: 11-60 mm), and neck angulation 30° ± 21 SD (range: 0°-70°). Fourteen had moderate to severe iliac tortuosity. A primary technical success rate of 80% was achieved (100% assisted primary technical success rate): 7 patients required adjunctive procedures intraoperatively and 2 successful treatments for type I endoleaks, which occurred within 24 hours postoperatively. There was 100% survival at 1-year follow-up; however, 4 (8.7%) patients required reintervention: 1 for a type I endoleak, 2 for limb stenosis, and 1 for a type II endoleak with an enlarging sac. No other device-related complications were identified. Reintervention and complication rates in hostile versus nonhostile anatomies were not statistically significant ( P = .28 and P = .42, respectively).

CONCLUSION

The Treovance stent graft has a comparable safety profile to other next-generation stent grafts during the first year after endovascular aneurysm repair, which provides a rationale for further interrogation of its outcomes through clinical trials.

Occlusive Shrinkage of Ovation Endograft Presenting as Acute Lower Limb Ischemia: Effective Endovascular Management

The aim of this report is to describe the imaging and successful treatment of an acute shrinkage of the Ovation Abdominal Stent Graft System. The Ovation Prime system utilizes a polymer-filled sealing ring that is cast in situ at the margin of the aneurysm; however, the residual endograft inner volume after ring filling may reduce volume and graft flow. Nevertheless, there are no reports about severe complications using the Ovation Prime system. A 75-year-old male presented to our hospital for acute lower limb ischemia. The patient reported a previous endograft for abdominal aortic aneurysm 1 month previously, which utilized the Ovation device. Computed tomography (CT) angiography demonstrated a critical narrowing of the endograft at the site of the proximal sealing rings. We decided on urgent treatment, delivering a covered stent graft (CP STENT NUMED^™). Intraoperative intravascular ultrasound showed effective compaction of the proximal rings. Nine-month follow-up with CT angiography demonstrated good patency without ring recoil of the endograft. This is the first report of endovascular treatment for an acute and symptomatic shrinkage of proximal rings in the Ovation trivascular endograft. Angiographic and intravascular ultrasound findings showed that covered stenting is effective and that the ring polymer is safely moldable.

Management of Difficult Access during Endovascular Aneurysm Repair

BACKGROUND

To describe a large single-institutional experience in managing challenging access situations during endovascular aneurysm repair (EVAR).

METHODS

Data from all patients undergoing EVAR at a tertiary academic medical center between 2009 and 2013 were collected retrospectively, including demographics, size of iliac arteries, type of device used, approach to managing difficult access (DA), and outcomes. The median follow-up was 38 months. DA was defined as iliac arteries with a diameter of less than 7 mm bilaterally. Fenestrated and snorkel repairs were excluded.

RESULTS

Of 400 EVARs performed during the study period, 191 (48%) were done in patients with DA. Of the DA patients, 35 (18.3%) underwent 42 adjuncts before the introduction of the main body device: including 15 dilators, 11 balloon angioplasties, 9 aortouniiliac devices, 3 SoloPath sheaths, 1 retroperitoneal cutdown, and 3 iliac stents. In another 29 patients, iliac stents were used to correct stenoses or kinks in the limbs after EVAR devices were deployed. The average diameter of the iliac artery used to deliver main body component was 4.6 mm in the group of patients requiring adjuncts and 5.4 mm in the remainder of the patients with small iliac arteries (P = 0.008). The median size of the main body device was 28 mm. Two cases were aborted due to inability to deliver the device. Other complications included 7 (3.6%) iliac ruptures, 3 (1.6%) instances of limb ischemia, and 5 (2.6%) patients needed early reoperation (within 30 days). Two patients (1%) had type I endoleaks at the conclusion of EVAR. During follow-up, 12 (6.3%) patients required EVAR revisions. Seven patients (3.6%) had limb thrombosis which occurred only in patients who did not have adjective procedures during the initial EVAR. Limb thrombosis and rate of revisions in patients with DA were not significantly different from the rates observed in non-DA patients. Perioperative mortality after elective repairs was 1.6% in DA patients and 0% in non-DA patients (P = 0.12).

CONCLUSIONS

EVAR can be successfully performed in patients with bilateral small iliac arteries. Adjunctive procedures might increase the technical success rate of EVAR in these patients and should definitely be considered in patients with iliac arteries less than 5 mm in diameter. Next generation and "low-profile" devices might minimize the need for adjunctive procedures and facilitate EVAR in these patients.