Outcomes of Endovascular AAA Repair in Patients with Hostile Neck Anatomy Using Adjunctive Balloon-Expandable Stents

Safety and Efficacy of Endovascular Aortic Repair for Abdominal Aortic Aneurysms with a Hostile Neck Anatomy

OBJECTIVE

This study aimed to investigate the safety and efficacy of endovascular aortic repair (EVAR) for the treatment of an abdominal aortic aneurysm (AAA) with a hostile neck anatomy (HNA).

METHODS

From January 1, 2015 to December 31, 2019, a total of 259 patients diagnosed with an AAA who underwent EVAR were recruited into this study. Based on the morphological characteristics of the proximal neck anatomy, the patients were divided into the HNA group and the friendly neck anatomy (FNA) group. The patients were followed up for up to 4 years.

RESULTS

The average follow-up time was 1056.1±535.5 days. Type I endoleak occurred in 4 patients in the HNA group, and 2 patients in the FNA group. Neither death nor intraoperative switch to open repair occurred in either group. The time of the operation was significantly longer in the HNA group (FNA vs. HNA, 99.2±51.1 min vs. 117.5±63.8 min, P=0.011). There were no significant differences in short-term clinical success rate (P=0.228) or midterm clinical success rate (P=0.889) between the two groups. The overall mortality rate was 10.4%, and Kaplan-Meier survival analysis indicated that the two groups had similar cumulative survival rates at the end of the follow-up period (P=0.889).

CONCLUSION

EVAR was feasible and safe in patients with an AAA with a proximal HNA. The early and midterm results were promising; however, further studies are needed to verify the long-term effectiveness of EVAR.

The Correlation of Aortic Neck Angle and Length in Abdominal Aortic Aneurysm with Severe Neck Angulation for Prediction of Intraoperative Neck Complications and Postoperative Outcomes after Endovascular Aneurysm Repair

OBJECTIVES

Endovascular aneurysm repair (EVAR) in a hostile neck has been associated with adverse outcomes. We aimed to determine the association of infrarenal aortic neck angle and length and establish an optimal cutoff value to predict intraoperative neck complications and postoperative outcomes.

METHODS

This was a retrospective review of patients with an intact infrarenal abdominal aortic aneurysm (AAA) with severe neck angulation (>60 degrees) who underwent EVAR from October 2010 to October 2018. Demographic data, aneurysm morphology, and operative details were collected. The ratio of neck angle and length was calculated as the optimal cutoff value of the aortic neck angle-length index. The patients were categorized into two distinct groups using latent profile analysis, a statistical technique employed to identify concealed subgroups within a larger population by examining a predetermined set of variables. Intraoperative neck complications, adjunct neck procedures, and early and late outcomes were compared.

RESULTS

115 patients were included. Group 1 (G1) had 95 patients with an aortic neck angle-length index ≤ 4.8, and Group 2 (G2) had 20 patients with an aortic neck angle-length index > 4.8. Demographic data and aneurysm morphology were not significantly different between groups except for neck length (p < 0.001). G2 had more intraoperative neck complications than G1 (21.1% vs. 55%, p = 0.005). Adjunctive neck procedures were more common in G2 (18.9% vs. 60%, p < 0.001). The thirty-day mortality rate was not statistically different. G1 patients had a 5-year proximal neck re-intervention-free rate comparable to G2 patients (93.7% G1 vs. 87.5% G2, p = 0.785). The 5-year overall survival rate was not statistically different (59.9% G1 vs. 69.2% G2, p = 0.891).

CONCLUSIONS

Patients with an aortic neck angle-length index > 4.8 are at greater risk of intraoperative neck complications and adjunctive neck procedures than patients with an aortic neck angle-length index ≤ 4.8. The 5-year proximal neck re-intervention-free rate and the 5-year survival rate were not statistically different. Based on our findings, this study suggests that the aortic neck angle-length index is a reliable predictor of intraoperative neck complications during EVAR in AAA with severe neck angulation.

Is Evar Feasible in Challenging Aortic Neck Anatomies? A Technical Review and Ethical Discussion

Background: Endovascular aneurysm repair (EVAR) has become an accepted alternative to open repair (OR) for the treatment of abdominal aortic aneurysm (AAA) despite “hostile” anatomies that may reduce its effectiveness. Guidelines suggest refraining from EVAR in such circumstances, but in clinical practice, up to 44% of EVAR procedures are performed using stent grafts outside their instruction for use (IFU), with acceptable outcomes. Starting from this “inconsistency” between clinical practice and guidelines, the aim of this contribution is to report the technical results of the use of EVAR in challenging anatomies as well as the ethical aspects to identify the criteria by which the “best interest” of the patient can be set. Materials and Methods: A literature review on currently available evidence on standard EVAR using commercially available endografts in patients with hostile aortic neck anatomies was conducted. Medline using the PubMed interface and The Cochrane Library databases were searched from 1 January 2000 to 6 May 2021, considering the following outcomes: technical success; need for additional procedures; conversion to OR; reintervention; migration; the presence of type I endoleaks; AAA-related mortality rate. Results: A total of 52 publications were selected by the investigators for a detailed review. All studies were either prospective or retrospective observational studies reporting the immediate, 30-day, and/or follow-up outcomes of standard EVAR procedures in patients with challenging neck anatomies. No randomized trials were identified. Fourteen different endo-grafts systems were used in the selected studies. A total of 45 studies reported a technical success rate ranging from 93 to 100%, and 42 the need for additional procedures (mean value of 9.04%). Results at 30 days: the incidence rate of type Ia endoleak was reported by 37 studies with a mean value of 2.65%; 31 studies reported a null migration rate and 32 a null conversion rate to OR; in 31 of the 35 studies that reported AAA-related mortality, the incidence was null. Mid-term follow-up: the incidence rate of type Ia endoleak was reported by 48 studies with a mean value of 6.65%; 30 studies reported a null migration rate, 33 a null conversion rate to OR, and 28 of the 45 studies reported that the AAA-related mortality incidence was null. Conclusions: Based on the present analysis, EVAR appears to be a safe and effective procedure—and therefore recommendable—even in the presence of hostile anatomies, in patients deemed unfit for OR. However, in order to identify and pursue the patient’s best interest, particular attention must be paid to the management of the patient’s informed consent process, which—in addition to being an essential ethical-legal requirement to legitimize the medical act—ensures that clinical data can be integrated with the patient’s personal preferences and background, beyond the therapeutic potential of the proposed procedures and what is generically stated in the guidelines.

First line Treatment of Traumatic Carotid Cavernous Fistulas Using Covered Stents at Level 1 Regional Trauma Center

Objective

The widely accepted treatment option of a traumatic carotid cavernous fistula (TCCF) has been detachable balloon or coils based fistula occlusion. Recently, covered stent implantation has been proving an excellent results. The purpose of this study is to investigate our experiences with first line choice of covered stent implantation for TCCF at level 1 regional trauma center.

Methods

From November 2004 to February 2020, 19 covered stents were used for treatment of 19 TCCF patients. Among them, 15 cases were first line treatment using covered stents. Clinical and angiographic data were retrospectively reviewed.

Results

Procedures were technically successful in all 15 cases (100%). Immediate angiographic results after procedure were total occlusion in 12 patients (80%). All patients except two expired patients had image follow-up (mean 15 months). Recurred symptomatic three patients underwent additional treatments and achieved complete occlusion. Mean clinical follow-up duration was 32 months and results were modified Rankin Scale 1–2 in five, 3–4 in five, and 5 in three patients.

Conclusion

The covered stent could be considered as fist line treatment option for treating TCCF patients especially in unstable vital sign. Larger samples and expanded follow-up are required to further develop their specifications and indications.

Early and late outcomes of endovascular aneurysm repair to treat abdominal aortic aneurysm compared between severe and non-severe infrarenal neck angulation

Background

Abdominal aortic aneurysm with severe infrarenal neck angle (>60°) has long been thought to be an obstacle to endovascular aneurysm repair. However, some previous studies reported endovascular aneurysm repair to be safe and efficacious for treating abdominal aortic aneurysm in patients with severe neck angulation. The aim of this study was to investigate the early and late outcomes of endovascular aneurysm repair to treat abdominal aortic aneurysm compared between patients with severe and non-severe infrarenal neck angulation.

Methods

Fifty-four severe and 144 non-severe neck angulation patients who were treated at Siriraj Hospital (Bangkok, Thailand) during January 2010–October 2013 were recruited. The primary endpoints were intraoperative neck complications (e.g., type 1A endoleak or proximal graft migration) and immediate adjunct aortic neck procedures. The secondary endpoints included perioperative mortality, overall survival, and the proportion of patients that were reintervention-free at five years compared between the severe and non-severe groups.

Results

Severe angulation patients were significantly older than non-severe angulation patients (77 ± 6.3 vs. 74 ± 7.9 years; p =  0.021). The median proximal angle was significantly greater in the severe group (82° vs. 13.5°; p <  0.001). Intraoperative proximal neck complications developed in 29.6% of patients in the severe angulation group compared with 9.0% in the non-severe group ( p <  0.001). Significantly more patients in the severe group required intraoperative adjunct procedures (29.6% vs. 7.6%; p <  0.001). There was no significant difference in perioperative mortality between groups. At the five-year follow-up, there was no significant difference between groups for overall survival or the proportion of patients that remained reintervention-free.

Conclusions

Endovascular aneurysm repair to treat abdominal aortic aneurysm in patients with severe proximal neck angulation is technically feasible and safe Although the severe angulation group had a higher rate of intraoperative neck complications and immediate adjunct neck procedures than the non-severe group, there was no significant difference between groups for 30-day mortality, overall survival or the proportion of patients who remained reintervention-free at five years.

Adjunctive Procedures for Challenging Endovascular Abdominal Aortic Repair: When Needed and How Effective?

Endovascular aneurysm repair (EVAR) is now considered the first choice treatment modality for abdominal aortic aneurysm (AAA) treatment. Advocates for endovascular strategies will try to treat all AAA by EVAR, regardless if the anatomy is conducive for treatment or not. However, the long-term outcomes of EVAR outside the instructions for use (IFU) due to a hostile aneurysmal neck or iliac artery anatomy are known to be poor. The EVAR procedures can be classified according to the technical difficulty, IFU, and need for visceral revascularization: standard, adjunctive, and complex EVAR. The situation required for adjunctive procedures can be classified as the following four steps: a hostile neck (i.e., short or severely angled); large inferior mesenteric or lumbar artery; tough iliac artery anatomy, such as a short common iliac artery and stenotic external iliac artery; and limitations in vascular access. This article will discuss the adjunctive procedures to overcome hostile aneurysm neck and unsuitable iliac artery anatomy.

Endoanchors under 3D image fusion for a type IA endoleak after EVAR

The Heli-FX technique for type IA EL under 3D-IF proved to be accurate in terms of EL channel vision and correct endoanchors deployment. The EL volume rendering constant view allowed a precise anchors fixation at the EL channel. 3D-IF confirmed to be a valid help in orientation and navigation during endovascular aortic procedure.

Severe infolding of fenestrated-branched endovascular stent graft

Infolding of a fenestrated-branched stent graft is an infrequent complication due to excessive oversizing. We report the case of an 89-year-old man who underwent a four-vessel fenestrated-branched endovascular aortic repair for a pararenal aortic aneurysm. Computed tomography angiography revealed severe infolding across the mesenteric-renal vessels. The patient was treated by angioplasty and placement of Palmaz stent. Cone-beam computed tomography confirmed patent visceral vessels with resolution of the infolding. This case illustrates an uncommon complication that can be prevented by modifications in the stent design and by immediate assessment using intraoperative cone-beam computed tomography.

A Word of Caution for Extra Large Self-expandable Nitinol Stents

BACKGROUND

To report an unsuccessful use of large nitinol stent to prevent proximal endoleak in endograft treatment for juxtarenal aortic aneurysm.

CASE REPORT

An 82-year-old male presented coronary disease and severe chronic obstructive pulmonary disease requiring oxygen support. A large 80-mm juxtarenal aneurysm was found on routine urological examination. Neck features were as follows: 7 mm and high anterior-posterior angulation. ASA risk score IV was given. Patient wanted to be treated. We decided a 1-shot intervention based on self-expandable suprarenal fixation endograft with adjunctive extra large self-expandable (high radial force) nitinol stent. Control computed tomography scan demonstrates nitinol stent severe infolding and a possible perforation of the primary endograft. At 6-month follow-up, sac reveals enlargement of 5 mm and 6% volume increase. Patient does not want further treatments due to high risk of procedures.

CONCLUSIONS

Extreme caution should be taken when using self-expandable extra large nitinol stents for preventive matters. Oversizing should be carefully considered, not necessarily reaching the endograft chosen size. When short and angulated neck morphology co-exists, other devices or procedures may be a better option.

Aortic Neck Anatomic Features and Predictors of Outcomes in Endovascular Repair of Abdominal Aortic Aneurysms Following vs Not Following Instructions for Use

BACKGROUND

A significant number of patients undergo endovascular repair of abdominal aortic aneurysms (EVAR) outside the instructions for use (IFU). This study will examine various aortic neck features and their predictors of clinical outcomes.

STUDY DESIGN

We performed a retrospective analysis of prospectively collected data on EVAR patients. Neck features outside IFU were analyzed. Kaplan-Meier and multivariate analyses were used to predict their effect as single features, or in combination, on outcomes.

RESULTS

Fifty-two percent of 526 patients had 1 or more features outside the IFU. The overall technical success rate was 99%, and perioperative complication rates were 7% and 12% for IFU vs outside IFU use, respectively (p = 0.04). Type I early endoleak and early intervention rates were 7% and 10% for IFU vs 18% and 24% for outside IFU (p = 0.0002 and p < 0.0001). At a mean follow-up of 30 months, freedom from late type I endoleak and late reintervention at 1, 2, and 3 years for IFU were 99.5%, 99.5%, and 98.4%, and 99.4%, 98%, and 96.8%; vs 98.9%, 98.1%, and 98.1%, and 97.5%, 96.2%, and 95.2% for outside IFU (p = 0.049 and 0.799), respectively. Survival rates at 1, 2, and 3 years for IFU were 97%, 93.5%, and 89.8%; vs 93.7%, 88.8%, and 86.3% for outside IFU (p = 0.035). Multivariate analysis showed that a neck angle > 60 degrees had odds ratios for death, sac expansion, and early intervention of 6, 2.6, and 3.3, respectively; neck length < 10 mm had odds ratios of 2.8 for deaths, 3.4 for early intervention, 4.6 for late reintervention, and 4.3 for late type I endoleak.

CONCLUSIONS

Patients with neck features outside IFU can be treated with EVAR; however, they have higher rates of early and late type I endoleak, early intervention, and late death.

Advanced Endovascular Approaches in the Management of Challenging Proximal Aortic Neck Anatomy: Traditional Endografts and the Snorkel Technique

Advances in endovascular technology, and access to this technology, have significantly changed the field of vascular surgery. Nowhere is this more apparent than in the treatment of abdominal aortic aneurysms (AAAs), in which endovascular aneurysm repair (EVAR) has replaced the traditional open surgical approach in patients with suitable anatomy. However, approximately one-third of patients presenting with AAAs are deemed ineligible for standard EVAR because of anatomic constraints, the majority of which involve the proximal aneurysmal neck. To overcome these challenges, a bevy of endovascular approaches have been developed to either enhance stent graft fixation at the proximal neck or extend the proximal landing zone to allow adequate apposition to the aortic wall and thus aneurysm exclusion. This article is composed of two sections that together address new endovascular approaches for treating aortic aneurysms with difficult proximal neck anatomy. The first section will explore advancements in the traditional EVAR approach for hostile neck anatomy that maximize the use of the native proximal landing zone; the second section will discuss a technique that was developed to extend the native proximal landing zone and maintain perfusion to vital aortic branches using common, off-the-shelf components: the snorkel technique. While the techniques presented differ in terms of approach, the available clinical data, albeit limited, support the notion that they may both have roles in the treatment algorithm for patients with challenging proximal neck anatomy.

Active Proximal Sealing in the Endovascular Repair of Abdominal Aortic Aneurysms

Purpose: To investigate the performance of a new device that uses the STRATA polytetrafluoroethylene graft material and a mechanism that provides active proximal sealing in order to prevent type Ia endoleak during endovascular aneurysm repair (EVAR). Methods: Between April 2013 and July 2014, 21 consecutive patients (all men; median age 71 years, range 60–84 years) with abdominal aortic aneurysm (median diameter 5.9 cm, range 4.9–7.8 cm) and suitable anatomy were offered elective EVAR using the AFX endograft. These patients had an irregular, conical, tapered, or bulging proximal neck, for which this specific device was considered appropriate. Aneurysm exclusion and incidence of type Ia endoleak were the primary outcomes; secondary outcomes included mortality, morbidity, migration, and other graft-related complications. Results: Primary technical success was 90%; 2 intraoperative type Ia endoleaks due to low endograft deployment were treated with additional proximal cuffs. During a median follow-up of 10 months (range 2–15 months), no type I endoleak was observed. One type II endoleak was encountered, with no associated sac enlargement. There was no stent-graft migration or any other device-related complication. One patient had a nonfatal myocardial infarction and another developed renal failure requiring transient dialysis. No deaths occurred. Conclusion: In this early experience, this newly available device appears to be safe and efficient in providing seal along irregularly shaped necks over the short term.

Immediate and two-year outcomes after EVAR in "on-label" and "off-label" neck anatomies using different commercially available devices. analysis of the experience of two Italian vascular centers

BACKGROUND

Endovascular aneurysm repair (EVAR) has fast become the therapeutic strategy of choice for abdominal aortic aneurysms (AAAs). Nowadays, the most important limit to the effectiveness of this technique is represented by complex anatomical situations, especially regarding the morphology of the proximal sealing zone. The aim of this study was to evaluate the 2-year outcome of unselected, real-world patients with "off-label" (off-L) proximal necks treated in 2 high-volume Italian vascular centers.

METHODS

A double-center study was conducted on a prospectively compiled computerized database between January 2010 and December 2011. One hundred and ninety-six consecutive elective surgery patients were analyzed and divided into 2 groups ("on-label" [on-L] and "off-L" necks) on the basis of their aortic neck anatomy. The neck was classified as an "off-L neck" in the presence of: (1) a noncylindrical neck, (2) an angulated neck, (3) a short neck, and (4) an enlarged neck. The end points were 30-day and 2-year technical and clinical success, evaluated in terms of freedom from reintervention and death.

RESULTS

One hundred and thirty-three elective patients were treated by standard EVAR in the presence of an "off-L" proximal neck anatomy. Technical success was achieved in all cases in both groups. Six (9.5%) unplanned adjunctive procedures were necessary in the on-L group and 16 (12%) in the off-L group (P = ns). Perioperative endoleaks, reinterventions, stent-graft migration rates, and AAA-related deaths were null. A multivariate analysis was performed to evaluate the subgroups of patients with 2 or > 2 anatomic factors that indicate a challenging neck. In patients with 2 such factors, a significant difference was observed in terms of intraoperative adjunctive procedures, intraoperative endoleaks, and all-cause mortality: 26.7% vs. 9.9% (P = 0.048), 6.7% vs. 0.5% (P = 0.023), and 13.3% vs. 1.1% (P = 0.0012), respectively. The same differences became increasingly evident when analyzing patients with > 2 criteria: 50% vs. 10% (P = 0.0022), 16.7% vs. 0.5% (P < 0.001), and 16.7% vs. 1.0% (P = 0.01). No AAA-related deaths or AAA ruptures were reported in either group at the end of the 2-year follow-up. High-flow endoleaks, stent-graft migration, and, consequently, reintervention were more frequent in the off-L group, but none of these parameters reached statistical significance.

CONCLUSIONS

Our experience seems to show that the off-L use of EVAR could be considered effective for the treatment of patients unfit for open surgery. In patients with more than one anatomical proximal neck feature contraindicating open surgery, the rate of immediate complications and reinterventions was higher, but this did not affect the clinical benefit and success at 2-year follow-up.

Endovascular treatment of infrarenal abdominal aortic aneurysm with short and angulated neck in high-risk patient

Endovascular treatment of abdominal aortic aneurysms (AAA) is an established alternative to open repair. However lifelong surveillance is still required to monitor endograft function and signal the need for secondary interventions (Hobo and Buth 2006). Aortic morphology, especially related to the proximal neck, often complicates the procedure or increases the risk for late device-related complications (Hobo et al. 2007 and Chisci et al. 2009). The definition of a short and angulated neck is based on length (<15 mm), and angulation (>60°) (Hobo et al. 2007 and Chisci et al. 2009). A challenging neck also offers difficulties during open repairs (OR), necessitating extensive dissection with juxta- or suprarenal aortic cross-clamping. Patients with extensive aneurysmal disease typically have more comorbidities and may not tolerate extensive surgical trauma (Sarac et al. 2002). It is, therefore, unclear whether aneurysms with a challenging proximal neck should be offered EVAR or OR (Cox et al. 2006, Choke et al. 2006, Robbins et al. 2005, Sternbergh III et al. 2002, Dillavou et al. 2003, and Greenberg et al. 2003). In our case the insertion of a thoracic endograft followed by the placement of a bifurcated aortic endograft for the treatment of a very short and severely angulated neck proved to be feasible offering acceptable duration of aneurysm exclusion. This adds up to our armamentarium in the treatment of high-risk patients, and it should be considered in emergency cases when the fenestrated and branched endografts are not available.

Women with abdominal aortic aneurysms have more extensive aortic neck pathology

BACKGROUND

The proportion of women with abdominal aortic aneurysm (AAA) treated with endovascular aortic repair (EVAR) is lower than for open repair (OR). Unfavorable morphologic features for EVAR in women with AAA may explain this disproportion. The objective of this study was to identify morphologic features in AAA patients undergoing elective repair with special emphasis on gender differences.

METHODS

Patients undergoing elective repair from January 1, 2006 to December 31, 2008 at our university's vascular unit were included in this study. Computed tomography (CT) angiograms were analyzed. Morphologic features considered unfavorable for EVAR rather than open repair (OR) included: infrarenal aortic neck <15 mm; angulation >60°; circumferential neck thrombus; neck width >32 mm; iliac arteries <7.5 mm; or presence of bi-iliac aneurysms. Complex aortic neck was defined as a neck length of <15 mm and one or more of the other aortic neck exclusion criteria.

RESULTS

One hundred seventy-two patients, including 140 men and 32 women, were treated during the study period, which included 99 with OR (21 women, 78 men) and 73 with EVAR (11 women, 62 men). Morphologic unsuitability for EVAR was 44% (75 of 172) and was not statistically different between women and men [47% (15 of 32) vs. 43% (60 of 140), P = 0.70]. Aortic neck pathology was the dominating feature for unsuitability for EVAR (69 of 75, 92%), and 85 of 172 patients had an unsuitable aortic neck. This rate was not different between women and men [19 of 32 (59%) vs. 66 of 140 (47%), P = 0.24]. Iliac unsuitability rates were 11% (19 of 172) and were not different between women and men [4 of 32 (12%) vs. 15 of 140 (11%), P = 0.76]. In patients unsuitable for EVAR, the proximal aortic necks showed more extensive aortic neck pathology in women than in men [8 of 15 (53%) vs. 13 of 60 (22%), P = 0.02]. More men had only short neck pathology [22 of 60 (37%) vs. 1 of 15 (7%), P = 0.03].

CONCLUSIONS

Aortic neck pathology is the dominating cause of EVAR exclusion in both genders. A higher proportion of women have more pathologic neck anatomy. Future development of EVAR devices should focus on the complexity of the aortic neck, which will benefit all AAA patients, but especially women.

Technical tips for successful outcomes using adjunctive procedures during endovascular aortic aneurysm repair

The inability to obtain proximal or distal seal continues to remain one of the main challenges of endovascular aneurysm repair. This is particularly relevant when endografts are used in patients with unsuitable proximal or distal landing zones. A variety of techniques can be used to achieve a seal in these difficult situations. Two specific techniques that can help intraoperatively to resolve the lack of adequate graft to aortic wall opposition are discussed in this article. These include the use of Palmaz stents for proximal seal and hypogastric snorkel for distal seal with internal iliac flow preservation.

AAA with a challenging neck: early outcomes using the Endurant stent-graft system

OBJECTIVES

The efficacy and safety of endovascular aneurysm repair is disputable in aneurysms with a short, angulated, wide, conical, or thrombus-lined neck making a reliable seal difficult to achieve. The influence of a challenging neck on early results using the Endurant stent-graft system in high risk patients was investigated.

MATERIALS AND METHODS

A retrospective study conducted on a prospectively compiled database of 72 elective patients with challenging neck treated with the Endurant system (Endurant Stent Graft, Medtronic AVE, Santa Rosa, CA, USA). These patients were compared to a control group (n = 65) without significant neck problems. Endpoints were early technical and clinical success, deployment accuracy and differences in operative details at one month follow-up. Data are reported as mean and standard deviation or as absolute frequency and percentage (%). Normality distribution and homogeneity of variances were tested by Shapiro-Wilks and Levene tests, respectively. Inter-group comparisons for each variable were made by t-test or χ2-test or Fisher exact test. A p < 0.05 was considered statistically significant.

RESULTS

Mean age was 76.12 years; 76.6% were males. Risk factors and pre-operative variables did not differ significantly between the two groups. Mean neck length was 10.56 mm in patients with challenging anatomies and 22.85 mm in controls. Patients with a challenging neck differed significantly (p < 0.001) from controls in terms of mean infrarenal (37.67° vs. 20.12°) and suprarenal angle (19.63° vs. 15.57°); 82% of patients with a challenging neck were ASA III/IV (vs. 86%). Technical success was 100%, with four unplanned proximal extension in challenging group. No type I endoleaks or aneurysm-related deaths occurred in either group; major complications were 1.54% vs. 1.39% (p = 0.942). Operative details were similar in both groups.

CONCLUSION

Treatment with the Endurant stent-graft is technically feasible and safe, yielding satisfactory results even in challenging anatomies. Medium- and long-term data are needed to verify durability, but early results are promising.

Endografts with suprarenal fixation do not perform better than those with infrarenal fixation in the treatment of patients with short straight proximal aortic necks

OBJECTIVE

To determine if there are any differences in outcomes between infrarenal fixation (IF) and suprarenal fixation (SF) endograft systems for the endovascular treatment (endovascular aneurysm repair [EVAR]) of abdominal aortic aneurysms (AAAs) with short, straight proximal aortic necks (<1.5 cm).

METHODS

A retrospective review of 1379 EVAR procedures was performed between the years of 2002 and 2009 at a single institution. The charts and radiographic images of all patients were reviewed. Patients who underwent EVAR with AAA morphology with short proximal necks were stratified into two groups: IF, Gore Excluder (W. L. Gore, Flagstaff, Ariz) group and SF, Cook Zenith (Cook, Bloomington, Ind) group. The primary end point for the study was the presence of proximal type 1 endoleaks. Secondary end points were graft migration at 1- and 2-year follow-up and aneurysm sac regression. The groups' demographics and comorbidities were also compared.

RESULTS

A total of 1379 EVARS were performed during the study period and 84 were identified as having a short proximal aortic neck. Sixty patients were in the IF group and 24 in the SF group. The average follow-up period was 18.6 months (IF) and 18.5 months (SF). There was no difference in the average proximal neck length (1.19 cm IF vs 1.14 cm SF; P = not significant [NS]) or the preoperative AAA size (5.8 cm IF vs 5.9 cm SF; P = NS). There were no significant differences in age (76.6 years IF vs 74.8 years SF; P = .32), gender (IF 66.7% vs SF 21.88% men; P = .053), or length of stay (2.2 days IF vs 1.9 days SF; P = .39). The comorbidities (diabetes, hypertension, and warfarin use) were also similar. There were five type 1a endoleaks in group IF and one in group SF (P = .44) identified at the 1-month follow-up; however, only one patient in the IF group underwent intervention for enlargement of the AAA sac. At 1 year, there was persistence of one type 1a endoleak in both groups, but these were deemed dead-end leaks as they did not fill the sac nor lead to aneurysm growth. There were no migrations (>0.5 cm) noted in either group. Sac regression was observed at an average rate of 0.24 cm/year in the IF group and 0.26 cm/year in the SF group (P = NS). There were no aneurysm ruptures during the study period.

CONCLUSIONS

There are no significant differences in endograft migration or in the incidence of early and late type 1a endoleaks between endografts that use IF (Gore Excluder) and SF (Cook Zenith) fixation for patients with short aortic necks undergoing EVAR.

A retrospective review of Palmaz stenting of the aortic neck for endovascular aneurysm repair

BACKGROUND

To review the aortic neck characteristics, graft types, and technical results of Palmaz stent placement as an adjunct to endovascular aneurysm repair (EVAR).

METHODS

A retrospective review of 110 consecutive EVAR cases identified 18 cases in which Palmaz stents were placed as an adjunct to EVAR. Graft types, hostile aortic neck features (neck diameter: >26 mm, length: <15 mm, angulation: >60°, reverse taper necks), and treatment success were identified.

RESULTS

Technical success in the placement of a proximal Palmaz stent was achieved in 17 of 18 cases. Palmaz stenting was attempted for the treatment of type I endoleak in 17 of 18 patients. One prophylactic stent was deployed in the setting of hostile neck anatomy. Proximal stent deployment resulted in immediate treatment success of type I endoleaks in 16 of 17 patients-one failure occurred in a patient who presented with a delayed type I endoleak. Analysis of aortic neck anatomy revealed that two of 18 patients had no criteria for a hostile neck, seven had one criterion, and nine met at least two criteria. With respect to stent-graft types, nine of 18 (50%) cases used the Endologix Powerlink, six used Gore Excluder, two used Cook Zenith, and one used Medtronic Talent. With a mean follow-up of 254 days, 16 of 17 type I endoleaks remain resolved.

CONCLUSIONS

With proper patient selection and additional adjunctive treatments, Palmaz stenting can effectively treat proximal type I endoleaks.

Technical modifications for endovascular infrarenal AAA repair for the angulated and dumbbell-shaped neck: the precuff Kilt technique

BACKGROUND

High risk surgical patients with abdominal aortic aneurysms and difficult infrarenal necks continue to be challenged when performing endovascular repair. Although fenestrated and branched endografts may ultimately be the main method of repair for these patients, their current limited availability has prompted the use of alternative endovascular techniques to enhance success of endovascular aortic aneurysm repair in patients with "dumbbell" shaped and angulated necks.

METHODS

A retrospective review of all patients who underwent endovascular abdominal aneurysm repair with a predeployed aortic cuff (Kilt) at University of California, Los Angeles between January 2009 and April 2010 was performed.

RESULTS

Four patients underwent initial Kilt placement before endovascular abdominal aortic aneurysm (AAA) repair. The mean age of these patients was 78.0 + 7.0 years. All were American Society of Anesthesiologists class 3 patients with multiple medical comorbidities. All of them had angulated and dumbbell-shaped necks. Median follow-up period was 11 months (8-18 months). All patients had postoperative computed tomography at 1 and 6 months because of their high-risk neck anatomy. One patient was found to have a large type I endoleak on computed tomography 1 month postoperatively. He required placement of an additional aortic cuff and Palmaz stent, after which the endoleak was found to have resolved. There were no open conversions, aneurysm sac enlargement, or perioperative deaths.

CONCLUSION

Short-term follow-up suggests that the Kilt technique may be useful in certain high-risk patients with traditionally unfavorable anatomy for endovascular abdominal aortic aneurysm repair. It can be performed with minimal patient morbidity, even in high-risk patients. Anatomic features most amenable to this technique include dumbbell-shaped and angulated infrarenal necks.

Carbon dioxide-enhanced CT-guided placement of aortic stent-grafts: feasibility in an animal model

PURPOSE

To test the feasibility of carbon dioxide (CO(2))-enhanced computed tomography (CT)-guided placement of infrarenal abdominal aortic stent-grafts in an animal model.

METHODS

Appearance of a stent-graft mounted on its deployment system and the feasibility of CT fluoroscopy-guided placement were analyzed in an in vitro setting. Five domestic pigs weighing 70 to 80 kg underwent CO(2)-enhanced 64-slice CT arteriography (CTA). After surgical exposure of the right iliac artery, an 18-mm stent-graft was advanced into the abdominal aorta. Infrarenal position of the graft was monitored using CT fluoroscopy with CO(2) administered intermittently in a flow-regulated manner using a computer-controlled injection system. After the final position of the stent-graft was determined, the graft was deployed under CT fluoroscopy guidance. Graft position was confirmed by contrast enhanced 64-slice CTA and conventional catheter angiography. To quantitatively assess the position of the stent-graft, the distance between the proximal stent struts and the radiopaque marker was determined using an electronic caliper.

RESULTS

CT-guided placement of infrarenal aortic stent-grafts was feasible in all animals without complications. CO(2)-enhanced CTA allowed for the identification of the renal arteries in all animals. CT fluoroscopy permitted the continuous online monitoring of stent deployment. In all animals, the grafts were placed without impairment of renal artery flow or stent-graft dislocation. The mean distance between the stent-graft and origin of the more caudal renal artery was 0.9+/-0.3 mm.

CONCLUSION

CO(2)-enhanced CT fluoroscopy permits the precise placement of infrarenal aortic stent-grafts in an animal model.

Novel technique for endovascular salvage of a folded aortic endograft

Endovascular aneurysm repair (EVAR) has been established as a safe and effective treatment modality for infrarenal abdominal aortic aneurysms. Endograft migration resulting in a proximal type I endoleak can be one of the most difficult challenges following EVAR. Often, this precludes endovascular treatment and necessitates conversion to open surgical repair. We report a case of a high-risk patient who presented with impending abdominal aortic aneurysm rupture as a result of endograft migration following EVAR performed 5 years prior. The endograft had folded over on itself within the aneurysm sac and was successfully repaired using a total endovascular approach.

Early and Late Clinical Outcomes of Endovascular Aneurysm Repair in Patients with an Angulated Neck

This study analyzed the clinical outcome in endovascular aneurysm repair (EVAR) patients with an angulated aortic neck. Two hundred thirty-eight EVAR patients underwent postoperative duplex ultrasonography and/or computed tomographic angiography, which was repeated every 6 to 12 months. Aortic neck angle was classified into < 45° (A1, n= 129), ≥ 45 to < 60° (A2, n = 43), and ≥ 60° (A3, n = 42). The perioperative complication rates for groups A1, A2, and A3 were 13%, 5%, and 29%, respectively ( p = .006). Proximal type I early endoleaks occurred in 9%, 33%, and 38% in groups A1, A2, and A3, respectively ( p < .0001). Intraoperative proximal aortic cuffs were needed in 7%, 28%, and 33% in groups A1, A2, and A3, respectively ( p < .0001). However, the rate of late reintervention was comparable in all groups. Postoperatively, the size of abdominal aortic aneurysm decreased or remained unchanged in 97%, 95%, and 84% in A1, A2, and A3, respectively ( p = .0147). The rates of freedom from late type I endoleak at 1, 2, and 3 years were 90%, 85%, and 85% for A1; 74%, 74%, and 68% for A2; and 64%, 64%, and 53% for A3 ( p = .0013). EVAR can be used for patients with an angulated aortic neck but was associated with a higher rate of early and late type I endoleaks and early interventions.