Impact of exclusion criteria on patient selection for endovascular abdominal aortic aneurysm repair

Evaluation of the renal function using serum Cystatin C following open and endovascular aortic aneurysm repair

Objectives

Controversies regarding renal function impairment after open and endovascular aortic aneurysm repair still exist. The purpose of this study was to evaluate the renal function following open repair and endovascular aneurysm repair using Cystatin C.

Methods

This prospective, observational case–control study was conducted in tertiary referral centre over 3 years, starting from 2012. In total, 60 patients operated due to infrarenal AAA either by means of open repair (30 patients) or endovascular aneurysm repair (30 patients) were included in the study. Biochemical markers of renal function (sCr, urea, potassium) were recorded pre-operatively and at these specific time points, immediately after the operation and at discharge, home (third postoperative day, endovascular aneurysm repair group) or from intensive care unit (third postoperative day, open repair group). Multivariate and propensity score adjustments were used to control for the baseline differences between the groups.

Results

Creatinine levels in serum remained unchanged during the hospital stay in both groups without significant differences at any time point. Cystatin C levels in endovascular aneurysm repair patients significantly increased postoperatively and restored to values comparable to baseline at the discharge (0.865 ± 0.319 vs. *0.962 ± 0.353 vs. 0.921 ± 0.322, * p < 0.001). Cystatin C levels in patients treated with the open surgery was decreasing over time but not statistically significant comparing to Cystatin C values at the admission. However, decrease in Cystatin C serum levels in patients treated with conventional surgery resulted in statistically significant lower values compared to endovascular aneurysm repair patients both postoperatively and at the time of discharge (0.760 ± 0.225 vs. 0.962 ± 0.353, p < 0.05; 0.750 vs. 0.156, p < 0.05). Both multivariate linear regression models and propensity score adjustment confirm that, even after correction for previously observed intergroup differences, type of surgery, i.e. endovascular aneurysm repair is independently associated with the higher levels of Cystatin C both postoperatively and at the discharge.

Conclusions

Dynamics of Cystatin C levels have been proven as a more vulnerable marker of renal dysfunction. Endovascular aneurysm repair is associated with higher levels of kidney injury markers.

Rationale for a new registry on EVAR: The EXTREME study

To report rationale of a physician-initiated study: Expanding Indications for Treatment with Standard EVAR in Patients with Challenging Anatomies, a Multi-Centric Prospective Evaluation - EXTREME.

•

Long term result after EVAR for AAA are still considered one of the main limits to the application of this treatment.

•

According with IFU and guidelines, EVAR still has several anatomical limitation.

•

Ovation Stent-Graft is an unique devices allowing to implement the range of patients amendable to be treated by EVAR.

Morphological suitability for endovascular repair, non-intervention rates, and operative mortality in women and men assessed for intact abdominal aortic aneurysm repair: systematic reviews with meta-analysis

BACKGROUND

Prognosis for women with abdominal aortic aneurysm might be worse than the prognosis for men. We aimed to systematically quantify the differences in outcomes between men and women being assessed for repair of intact abdominal aortic aneurysm using data from study periods after the year 2000.

METHODS

In these systematic reviews and meta-analysis, we identified studies (randomised, cohort, or cross-sectional) by searching MEDLINE, Embase, CENTRAL, and grey literature published between Jan 1, 2005, and Sept 2, 2016, for two systematic reviews and Jan 1, 2009, and Sept 2, 2016, for one systematic review. Studies were included if they were of both men and women, with data presented for each sex separately, with abdominal aortic aneurysms being assessed for aneurysm repair by either endovascular repair (EVAR) or open repair. We conducted three reviews based on whether studies reported the proportion morphologically suitable (within manufacturers' instructions for use) for EVAR (EVAR suitability review), non-intervention rates (non-intervention review), and 30-day mortality (operative mortality review) after intact aneurysm repair. Studies had to include at least 20 women (for the EVAR suitability review), 20 women (for the non-intervention review), and 50 women (for the operative mortality review). Studies were excluded if they were review articles, editorials, letters, or case reports. For the operative review, studies were also excluded if they only provided hazard ratios or only reported in-hospital mortality. We assessed the quality of the studies using the Newcastle-Ottawa scoring system, and contacted authors for the provision of additional data if needed. We combined results across studies by random-effects meta-analysis. This study is registered with PROSPERO, number CRD42016043227.

FINDINGS

Five studies assessed the morphological eligibility for EVAR (1507 men, 400 women). The overall pooled proportion of women eligible (34%) for EVAR was lower than it was in men (54%; odds ratio [OR] 0·44, 95% CI 0·32-0·62). Four single-centre studies reported non-intervention rates (1365 men, 247 women). The overall pooled non-intervention rates were higher in women (34%) than men (19%; OR 2·27, 95% CI 1·21-4·23). The review of 30-day mortality included nine studies (52 018 men, 11 076 women). The overall pooled estimate for EVAR was higher in women (2·3%) than in men (1·4%; OR 1·67, 95% CI 1·38-2·04). The overall estimate for open repair also was higher in women (5·4%) than in men (2·8%; OR 1·76, 95% CI 1·35-2·30).

INTERPRETATION

Compared with men, a smaller proportion of women are eligible for EVAR, a higher proportion of women are not offered intervention, and operative mortality is much higher in women for both EVAR and open repair. The management of abdominal aortic aneurysm in women needs improvement.

FUNDING

National Institute for Health Research (UK).

Cinical outcomes of Endurant II stent-graft for infrarenal aortic aneurysm repair: comparison of on-label versus off-label use

PURPOSE

We aimed to compare the outcomes of the Endurant II (Medtronic) stent-graft used under instructions for use versus off-label in high-risk patients considered unfit for conventional surgery.

METHODS

Data from patients treated with the Endurant II stent-graft between December 2012 and March 2015 were retrospectively analyzed. Sixty-four patients were included. Patients were assigned to group A if treated under instructions for use (n=34, 53%) and to group B if treated off-label (n=30, 47%). Outcome measures included perioperative mortality and morbidity, survival, freedom from reintervention, endoleak incidence, in-hospital length of stay, and mean stent-graft component used. Mean follow-up was 22.61±12 months (median, 21.06 months; range, 0-43 months).

RESULTS

One perioperative mortality (1.6%) and one perioperative complication (1.6%) occurred in group B. At two months follow-up, one iliac limb occlusion (1.6%) occurred in group A. No type I/III endoleaks were recorded. A type II endoleak was identified in three cases (4.7%). Overall survival at three years was 89% (97% for group A, 82% for group B; P = 0.428). Reintervention-free survival at three years was 97% for both groups (P = 0.991). A longer in-hospital stay was observed in group B (P = 0.012).

CONCLUSION

The Endurant II (Medtronic) new generation device was safe in off-label setting at mid-term follow-up. The off-label use of the Endurant II (Medtronic) is justified in patients considered unfit for conventional surgery. Larger studies are required in this subgroup of patients.

A clinical and ethical review on late results and benefits after EVAR

Introduction

The aim of this review is to assess if late mortality after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is a real problem, and whether it could be an issue in the case of medical litigation.

Material and methods

A review of all English language literature was performed on PubMed web-site, looking for all papers reporting EVAR long-term mortality rate. EVAR performances were reviewed also from an ethical and medico-legal point of view, based on current Italian laws.

Results

Mono-centric studies, and international registers suggest that today EVAR offers similar (if not better) results than open repair (OR) in the treatment of AAAs with standard and complex anatomies, even if performed outside the devices-specific instructions for use. In contrast, large randomized trials, and consequently current guidelines, suggest that EVAR still has an ancillary role compared to OR, only to be used for highly selected patients.

Recently, specific litigation cases on surgical options related to the treatment of aortic aneurysms has developed. The informed consent process needs to include not only mortality and major complications related to the procedure but also the chance of patients' outcomes. For those reasons, the generic nature of informed consent has been criticized.

Conclusions

No conclusive data is currently available to assess the initial question of late mortality after EVAR but results are still improving. In the meantime, widespread use of EVAR as first choice for treating AAA may only be acceptable in high-volume centres validating their results by a strict follow up protocol.

•

The long-term results after endovascular repair (EVAR) for abdominal aortic aneurysms (AAA) are still considered one of the main limitations of this treatment option.

•

This paper is a comprehensive review of the current literature on long-term mortality after EVAR procedures.

•

An analysis on informed consent for EVAR from a non-surgical point of view is reported for the very first time.

Outcomes of Endovascular Repair of Aortoiliac Aneurysms and Analyses of Anatomic Suitability for Internal Iliac Artery Preserving Devices in Japanese Patients

BACKGROUND

Understanding that the common iliac arteries (CIA) are shorter in Asian patients, we investigated whether this anatomic difference affects the clinical outcomes of internal iliac artery (IIA) exclusion during endovascular aneurysm repair (EVAR) of aortoiliac aneurysm and thus limits the use of IIA-preserving devices in Japanese patients.Methods and Results:From 2008 to 2014, 69 Japanese patients underwent EVAR of aortoiliac aneurysms with 53 unilateral and 16 bilateral IIA exclusions. One patient had persistent buttock claudication during follow-up; however, colonic or spinal cord ischemia was not observed. Anatomic suitability was investigated for the iliac branch device (IBD) by Cook Medical and the iliac branch endoprosthesis (IBE) by WL Gore: 87 aortoiliac segments were analyzed, of which 17% met the criteria for the IBD, 25% met the criteria for the IBE and 40% met the criteria for either. Main exclusions for the IBD were IIA diameter >9 mm or <6 mm (47%) and CIA length <50 mm (39%). Main exclusions for the IBE were proximal CIA diameter <17 mm (44%) and aortoiliac length <165 mm (24%).

CONCLUSIONS

EVAR with IIA exclusions in Japanese patients showed low incidence of persistent buttock claudication and no major pelvic complications. Aorto-iliac morphology demonstrated smaller proximal CIA diameters and shorter CIA lengths, limiting the use of IIA-preserving devices.

Midterm Results of Proximal Aneurysm Sealing With the Ovation Stent-Graft According to On- vs Off-Label Use

Purpose: To compare the use of the Ovation stent-graft according to the ≥7-mm neck length specified by the original instructions for use (IFU) vs those treated off-label (OL) for necks <7 mm long. Methods: A multicenter retrospective registry (TriVascular Ovation Italian Study) database of all patients who underwent endovascular aneurysm repair with the Ovation endograft at 13 centers in Italy was interrogated to identify patients with a minimum computed tomography (CT) follow-up of 24 months, retrieving records on 89 patients (mean age 76.4±2.4 years; 84 men) with a mean follow-up of 32 months (range 24–50). Standard CT scans (preoperative, 1-month postoperative, and latest follow-up) were reviewed by an independent core laboratory for morphological changes. For analysis, patients were stratified into 2 groups based on proximal neck length ≥7 mm (IFU group, n=57) or <7 mm (OL group, n=32). Outcome measures included freedom from type Ia endoleak, any device-related reintervention, migration, and neck enlargement (>2 mm). Results: At 3 years, there was no aneurysm-related death, rupture, stent-graft migration, or neck enlargement. There were no differences in terms of freedom from type Ia endoleak (98.2% IFU vs 96.8% OL, p=0.6; hazard ratio [HR] 0.55, 95% CI 0.02 to 9.71 or freedom from any device-related reintervention (92.8% IFU vs 96.4% OL, p=0.4; HR 2.42, 95% CI 0.34 to 12.99). In the sealing zone, the mean change in diameters was −0.05±0.8 mm in the IFU group and −0.1±0.5 mm in the OL group. Conclusion: Use of the Ovation stent-graft in patients with neck length <7 mm achieved midterm outcomes similar to patients with ≥7-mm-long necks. These midterm data show that the use of the Ovation system for the treatment of infrarenal abdominal aortic aneurysm is not restricted by the conventional measurement of aortic neck length, affirming the recent Food and Drug Administration–approved changes to the IFU.

Hemodynamics study of a multilayer stent for the treatment of aneurysms

Background

The changes of hemodynamics caused by the implantation of multilayer stent (MS) have significant effects for aneurysm sac.

Methods

Comparisons of 3D numerical models with/without a MS in an abdominal aortic aneurysm with a 90° branch vessel were numerically studied from the viewpoint of hemodynamics.

Results

The results showed that: (1) The flow fields and Wall Shear Stress (WSS) are changed dramatically after MS implantation. The velocity of the blood flow in aneurysm sac decreases significantly and the regions of low-WSS increase. These help thrombus formation; (2) The pressure in aneurysm slightly decreases and keeps close to the normal level of blood pressure, however the risk of aneurysm enlargement or even rupture still exists; (3) The flux and the velocity in branch artery are reduced by about half after MS implantation. Due to the implantation of MS, the changes in the flow field causes the decrease of pressure/WSS in aneurysm sac and the blood flow in branch vessel.

Conclusions

The implantation of MS into abdominal artery results in more low-WSS regions inside aneurysm which induces thrombus formation. The pressure is reduced slightly means the risk of aneurysm rupture exists.

3D printing guiding stent graft fenestration: A novel technique for fenestration in endovascular aneurysm repair

Objective To describe a novel approach, 3D printing guiding stent graft fenestration, for fenestration during endovascular aneurysm repair for juxtarenal abdominal aortic aneurysm. Methods A 69-year-old male with juxtarenal abdominal aortic aneurysm underwent endovascular aneurysm repair with "off the label" fenestrated stent graft. To precisely locate the fenestration position, we reconstructed a 3D digital abdominal aortic aneurysm model and created a skin template covering this abdominal aortic aneurysm model. Then the skin template was physically printed and the position of the visceral vessel was hollowed out, thereby helping in locating the fenestration on stent graft. Results and conclusions With the help of this 3D printed skin template, we fenestrated the stent graft accurately and rebuilt the bilateral renal artery successfully. This is the first clinical case that used 3D printing guiding stent graft fenestration, which is a novel approach for precise fenestration on stent graft on the table during endovascular aneurysm repair.

Barriers to Endovascular Aortic Aneurysm Repair: Past Experience and Implications for Future Device Development

Despite improvements in endovascular aortic aneurysm repair (EVAR) devices and techniques, significant anatomic constraints still preclude successful EVAR in a large number of patients. The authors sought to identify the current barriers to EVAR and examine their evolution over time. Patients were evaluated for potential endovascular repair by computed tomography angiography (CTA) with or without supplemental conventional arteriograms. The patient population was separated into 2 groups (A and B) based on early and late time periods in the experience with EVAR, corresponding to the availability of various devices. Group A (early) consisted of the Guidant Ancure, Medtronic Talent, and AneuRx devices and comprised patients presenting between April 1997 through June 2000. Group B (late) consisted of the Medtronic AneuRx, Cook Zenith, Edwards Lifepath, Gore Excluder, and Endologix PowerLink devices and comprised patients presenting between July 2000 and December 2003. Patient demographics and anatomic reasons for rejection were recorded in a database for statistical analysis. In total, 547 patients were evaluated (463 men, 84 women). Of these, 346 patients (63%; 312 men, 34 women) were deemed suitable candidates for EVAR and 201 (37%; 151 men, 50 women) were rejected. There was no significant difference in the overall rate of rejection in the early vs the late time period (34% A, 41% B, p= 0.08), but the number of exclusion criteria per patient decreased over time; patients rejected for EVAR had an overall average of 1.6 exclusion criteria (Group A, 1.9; Group B, 1.2). The reasons for rejection did significantly change over time. Specifically, rejection on the basis of inadequate arterial access, presence of extensive iliac artery aneurysms, or an inadequate proximal neck decreased. A disproportionate number of women were excluded throughout the study: Group A, 56% of women compared to 30% of men (p= 0.0003); Group B, 63% of women compared to 36% of men (p= 0.0022). Women were more likely than men to have inadequate arterial access routes. In addition, patients with high operative risk were also more likely to be excluded from EVAR, a finding that persisted over time. Anatomic constraints continue to pose significant challenges to aortic endografting. Progress has been made in that technological advances have conquered some of the previous anatomic challenges, chiefly those of arterial access and treatment of concomitant iliac aneurysm disease. However, the overall rate of rejection for EVAR remains the same. The chief anatomic barriers continue to be the difficult aortic neck and management of branched vascular segments.

Endovascular vs Open AAA Repair: Does Size Matter?

Since the natural tendency of the aorta is to increase in diameter and tortuosity with age and since abdominal aortic aneurysms (AAAs) increase in diameter and length over time, encroaching on the renal and hypogastric orifices, early repair of AAAs (when =4.0 cm) may allow greater applicability of the endovascular option because of more favorable aortoiliac morphology. Patients who present at an older age with larger AAAs should be more likely to be anatomically excluded from endovascular AAA repair. Over a 42-month period, 317 consecutive patients referred with aortoiliac aneurysms (infrarenal AAA =4.0 cm) were evaluated by one of the authors (SGL) for endovascular vs open repair based on computed tomography (CT) and angiographic imaging. The 10 anatomic exclusion criteria were those applicable to the Zenith ® endograft (Cook, Inc), which currently is the most anatomically inclusive of the aortic endografts in commercial use in the United States. Based on their aortoiliac morphology, 212 patients were excluded from endovascular repair and 105 were included as acceptable anatomic candidates. Age, AAA size, and the reason(s) for exclusion were recorded for each patient. By use of Student's t test and logistic and linear regression analyses, the groups were compared by age, AAA size, and age + size. There was no significant difference in patient age or AAA size distribution between the group of patients excluded from endovascular repair based on aortoiliac morphology compared to those who met the inclusion criteria. Patients with small AAAs (4.0–5.4 cm) had similar age distribution as those with large (=5.5 cm) AAAs. The majority of patients (87%) were excluded based on proximal aortic neck morphology. The presence of aortoiliac morphology that precludes endovascular repair is independent of patient age or AAA size at presentation. A patient presenting with a small (4.0–5.4 cm) AAA is not more likely to be a candidate for endovascular repair than a patient with a large AAA.

Modular Branched Endograft System for Aortic Aneurysm Repair: Evaluation in a Human Cadaver Circulation Model

A circulation model was created in 6 nonaneurysmal human cadavers to evaluate the deliverability, deployment, and acute performance of a modular branched endograft system for treatment of aortic aneurysms containing essential branch vessels. Two fenestrations were created in an appropriately sized aortic main endograft. Under fluoroscopic guidance, the main endograft was advanced to the target site and the fenestrations were aligned with the ostia of the renal arteries. Branch grafts were placed through the fenestrations into the renal arteries. The outcome was evaluated by post implant angiography and autopsy. Eleven branch grafts were deployed at the target site. All targeted renal arteries showed good patency. At autopsy, all main endografts were adequately deployed, and 10 of 11 branch grafts were locked in place. In this model, deliverability and deployment of the modular branch graft system is feasible in a reliable, predictable, and timely fashion.

Early experience with the new endovascular aneurysm sealing system Nellix: First clinical results after 50 implantations

Objective

In the present study, 50 EVAS procedures were evaluated in regard to primary (survival and technical success) and secondary (device-related complications) events of interest.

Methods

The single center study was conducted from July 2013 to August 2014 with prospective collection of the clinical data. The clinical results were controlled by CT angiography and contrast-enhanced ultrasound .

Results

The technical success was 98% and the 30-day mortality 4%. One (2%) patient died from multisystem organ failure and another patient from an intracranial bleeding, respectively. One patient (2%) suffered from a device-related aneurysm rupture. During early follow-up, one (2%) patient developed an endoleak type II, while three (6%) patients suffered from a partial endograft limb thrombosis. Overall, a secondary intervention was necessary in six (12%) patients.

Conclusions

With the Nellix EVAS system, a high primary technical success of 98% was achieved; one (2%) patient developed an endoleak type II which did not require secondary intervention. Those promising results are contrasted by a substantial rate of endograft limb thromboses (8%) and one (2%) intraoperative aneurysm rupture. Further studies are needed to assess the durability of the Nellix stentgraft and the occurrence of device-related complications.

Risk Factor Analysis for Buttock Claudication after Internal Iliac Artery Embolization with Endovascular Aortic Aneurysm Repair

Purpose:

Endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) involving the common iliac artery requires extension of the stent-graft limb into the external iliac artery. For this procedure, internal iliac artery (IIA) embolization is performed to prevent type II endoleak. In this study, we investigated the frequency and risk factor of buttock claudication (BC) in patients having interventional embolization of the IIA.

Materials and Methods:

From January 2010 to December 2013, a total of 110 patients with AAA were treated with EVAR in our institution. This study included 27 patients (24.5%) who had undergone unilateral IIA coil embolization with EVAR. We examined hospital charts retrospectively and interviewed by telephone for the occurrence of BC.

Results:

Mean age of total patients was 71.9±7.0 years and 88.9% were males. During a mean follow-up of 8.65±9.04 months, the incidence of BC was 40.7% (11 of 27 patients). In 8 patients with claudication, the symptoms had resolved within 1 month of IIA embolization, but the symptoms persisted for more than 6 months in the remaining 3 patients. In univariate and multivariate analysis, risk factors such as age, sex, comorbidity, patency of collateral arteries, and anatomical characteristics of AAA were not significantly related with BC.

Conclusion:

In this study, BC was a frequent complication of IIA embolization during EVAR and there was no associated risk factor. Certain principles such as checking preoperative angiogram, proximal and unilateral IIA embolization may have contributed to reducing the incidence of BC.

Fenestrated Endografting for Aortic Aneurysm Repair: A 7-Year Experience

Purpose:

To present a 7-year single-center clinical experience with fenestrated endografts and side branches.

Methods:

Between April 1999 and August 2006, 63 patients (57 men; mean age 70.5611.6 years, range 25–89) received custom-designed Zenith fenestrated endoprostheses for a variety of aneurysms (59 abdominal, 1 thoracoabdominal, and 3 thoracic). They were all unsuitable for standard EVAR owing to short aortic necks and high risk for open surgery.

Results:

Nineteen tube grafts and 44 composite bifurcated grafts with a total of 122 fenestrations and 58 side branches were used. Technical success was achieved in 55 (87.3%) patients and in 118 (96.7%) vessels. Treatment success was 93.7%. The mean follow-up was 23±18 months (median 14, range 6–77). Overall, 9 (7.4%) visceral branches were lost: 4 intraoperative, 2 perioperative, and 3 late. There were 12 (19.0%) endoleaks identified: 5 (7.9%: 4 type Ia and 1 fenestration-related type III) primary and 7 (11.1%: 4 type II, 1 type I, and 2 type III) secondary endoleaks; 4 resolved, 4 were treated, and 4 are under observation. At 77 months, 75.3% of patients were free of a reintervention. All reinterventions were performed within the first 14 months. Fourteen cases of renal impairment were seen [6 permanent (only 1 on dialysis) and 8 transient]. One (1.6%) conversion and 1 (1.6%) rupture were recorded; aneurysm-related mortality was 4.8% (3/63).

Conclusion:

The favorable outcomes in this study, which encompasses the team's learning curve with fenestrated endografts and side branches, support the use of these devices in selected patients.

Spontaneous Sealing of a Type Ia Endoleak after Ovation Stent Graft Implantation in a Patient with On-Label Aortic Neck Anatomy

We report a case of an early type Ia endoleak after endovascular aneurysm repair (EVAR) of an abdominal aortic aneurysm by Ovation Stent Graft implantation and spontaneously resolved without further reintervention. The patient presents a conical aortic neck, but EVAR was performed within the instruction for use proposed by manufactory. At completion angiography, a low-flow type Ia endoleak was present and left untreated. Computed tomographic angiography performed on the third postoperative day showed infolding of the 2 sealing rings. The patient was dismissed without further treatment. At 3-month follow-up, the leak appeared spontaneously sealed with partial expansion of the 2 rings.

Fenestrated endovascular repair of abdominal aortic aneurysms: a less invasive option for the treatment of juxtarenal aortic aneurysms

Endovascular aortic aneurysm repair has become the predominant surgical therapy for abdominal aortic aneurysms. Whereas anatomical limitations had become the major contraindication to endovascular treatment, fenestrated stent grafts were developed to overcome such obstacles. Fenestrated endovascular aortic aneurysm repair now provides an additional treatment option for patients felt to be unsuitable for an invasive open repair whose anatomy is not compatible with more traditional stent grafts. We review the evolution of fenestrated endovascular aortic aneurysm repair and compare its safety and efficacy to other endovascular options.

Management of concomitant abdominal aortic aneurysm and colorectal cancer

OBJECTIVE

To conduct a systematic review of the literature and perform an analysis of outcomes of treatment of concomitant colorectal cancer (CRC) and abdominal aortic aneurysm (AAA) with a focus on the different treatment options and the related therapeutic outcomes.

METHODS

A review of the English-language medical literature from 1980 to 2015 was undertaken using the PubMed and EMBASE databases to identify studies reporting surgical treatment of patients with concomitant CRC and AAA. The search identified 24 articles encompassing 254 patients (81% male; mean age 73.5 ± 6.1 years).

RESULTS

In 96 patients (37.9%) cancer resection was performed first, followed by AAA repair at a later stage (open aortic repair [OAR], 79.2%; endovascular abdominal aortic repair [EVAR], 20.8%). Eighty-two patients (32.3%) underwent AAA repair (OAR, 47.5%; EVAR, 52.5%) before CRC resection. Seventy-one patients (27.9%) underwent combined OAR and CRC resection, and just five (1.9%) were treated with EVAR and cancer surgery in a single stage. There were eight of 96 interval AAA ruptures (8.3%), mostly in the early postoperative period concerning aneurysms >6 cm in diameter. The mean interval between the two procedures was much shorter in patients treated with EVAR than OAR (11.5 ± 1.8 days vs 103.9 ± 42.3 days). The overall 30-day mortality rate was 10.9%. Data from observational studies showed no significant differences in 30-day mortality between patients treated in one or two stages (P = .89). No mortality was recorded in any of the EVAR-treated patients. There was only one graft infection recorded (0.4%).

CONCLUSIONS

Among different approaches, no significant differences in 30-day outcomes among patients treated in either two or one stage were evident. EVAR showed the lowest mortality and also diminished the delay between the two procedures in <2 weeks for a two-stage approach, although it has been associated with a significant risk for thrombotic events. The coexistence of AAA and CRC seems to favor the use of EVAR in treating those patients.

Preliminary results of adjunctive use of endoanchors in the treatment of short neck and pararenal abdominal aortic aneurysms

OBJECTIVES

To present our initial experience with the use of EndoAnchors for endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with little to no infrarenal landing zone.

BACKGROUND

EndoAnchors have been reported to assist in the prevention and treatment of type 1a endoleaks in patients with hostile aortic necks who undergo EVAR.

METHODS

Between July 2013 and July 2014, nine patients with AAAs and short proximal aortic necks (i.e., 0-10 mm in length) underwent EVAR. In five patients, utilization of the chimney graft technique was necessary. A mean of 2.5 (range 1-4) visceral vessels underwent chimney graft. The prophylactic use of EndoAnchors was utilized in all 9 patients. The decision to use the EndoAnchors was made in the preoperative planning phase.

RESULTS

Technical success was achieved in 100% of cases. In two cases, type 1a endoleaks were noted before the deployment of any EndoAnchors. In both cases, a final angiogram depicted resolution of the type 1a endoleak after insertion of the EndoAnchors. Mean follow-up time was 8 months. At 30 days, 3 months, and 6 months, 100% of the endografts remained patent and free from type 1a endoleaks. No adverse renal complications or mortality was reported.

CONCLUSIONS

EndoAnchors are an applicable adjunct to EVAR as treatment for short infrarenal neck and pararenal AAAs. Further investigations are needed to determine the durability of this novel application.

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.

The Current State of Fenestrated and Branched Devices for Abdominal Aortic Aneurysm Repair

Endovascular abdominal aortic aneurysm repair (EVAR) provides an attractive alternative to traditional open techniques. Endovascular repair is frequently limited by aortic aneurysm neck angulation, the absence of an adequate infrarenal neck, and the need for internal iliac preservation. Several devices have been created to incorporate visceral artery segments as well as preserve the internal iliac artery, thus broadening the patient population suited for endovascular repair. This article will provide a review of the current literature regarding fenestrated devices, branch devices, off-the-shelf devices, and physician-modified devices. It will also highlight the iliac branch stent grafts currently on trial for internal iliac artery preservation. Data thus far have suggested that these devices will be both a safe and effective option for anatomically challenging abdominal aortic aneurysms.

Studying the Interaction of Stent-Grafts and Treated Abdominal Aortic Aneurysms

Since the advent of endovascular repair of aortic aneurysms (EVAR), clinical focus has been on preventing loss of sealing at the level of the infrarenal neck, which leads to type I endoleak and repressurization of the aneurysm sac. Enhanced mechanisms for central fixation and seal have consequently lowered the incidence of migration and endoleaks. However, endograft limb thrombosis and its causal mechanisms have not been addressed adequately in the literature. This article reviews the pathophysiological mechanisms associated with limb thrombosis in order to facilitate better clinical judgment to prevent iliac adverse effects.

Performance of the Endurant stent graft in challenging anatomy

OBJECTIVE

This study aimed to compare perioperative and postoperative outcomes after endovascular repair of abdominal aortic aneurysms (AAAs) in patients with various neck morphologic features.

METHODS

Data from the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) were used for the analyses. Patients were categorized into three different groups according to proximal aortic neck anatomy: regular (REG), intermediate (INT), and challenging (CHA). REG was defined as AAAs with a proximal neck ≥15 mm combined with a suprarenal angulation (α) ≤45 degrees and an infrarenal neck angulation (ß) ≤60 degrees. INT was defined as AAAs with a proximal neck of 10 to 15 mm combined with α ≤45 degrees and ß ≤60 degrees or with a proximal neck of >15 mm combined with α ≤60 degrees and ß = 60 to 75 degrees or α = 45 to 60 degrees and ß ≤75 degrees. CHA was defined as infrarenal necks that exceed at least one of the three defining factors.

RESULTS

Overall, 925 patients (75.9%) had REG anatomy, 189 patients (15.5%) had INT anatomy, and 104 patients (8.5%) had CHA anatomy. Patient demographics and risk factors were similar. There was a significant difference in AAA diameter between the REG and CHA groups (59.4 mm vs 65.2 mm; P < .001). Technical success was similar among groups (REG 99.1% vs INT 99.5% vs CHA 97.1%). There were no differences in mortality or the need for secondary procedures within 30 days or at 1 year. A significantly higher rate of type I endoleaks within 30 days was seen in CHA compared with REG (adjusted odds ratio, 0.15; 95% confidence interval, 0.05-0.46) and INT (adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.70), but there was no difference at 1-year follow-up.

CONCLUSIONS

This real-world, global experience shows promising results and indicates that endovascular AAA repair with the Endurant stent graft (Medtronic Vascular, Santa Rosa, Calif) is safe and effective in patients with challenging aortic neck anatomy. However, long-term follow-up of patients is required to confirm results.

Initial single-center experience with the Ovation stent-graft system in the treatment of abdominal aortic aneurysms: application to challenging iliac access anatomies

BACKGROUND

To present our preliminary results with the Ovation(™) abdominal stent-graft system in abdominal aortic aneurysms (AAA) with narrow (≤7 mm) or angulated iliac vessels.

METHODS

From April 2012 to January 2014, 42 patients (97% men; mean age, 71 years; range, 55-89 years) with AAAs of 55.5 mm (50-79 mm) were treated with the Ovation device. Primary end points included technical success and freedom from early secondary interventions, any type of endoleak, and aneurysm-related death. Limb occlusion was studied with respect to iliac access diameter and angulation. Iliac angulation between 90° and 120° or <90° was considered moderate or severe, respectively.

RESULTS

The postoperative follow-up was 7.8 ± 4.6 months (mean ± standard deviation). Infrarenal neck angulation was 26° ± 26°. AAA neck length and diameter were 27.3 ± 10.5 and 24.1 ± 3.2 mm, respectively. Forty-five percent of patients had at least 1 vessel of ≤7-mm diameter, and almost half of patients (24 of 44) had at least 1 iliac artery of moderate or severe angulation. Technical and treatment success were 100% and 95%, respectively. No stent-graft migration or type I, III, or IV endoleaks occurred. Type II endoleaks were identified in 5 patients, leading to sac enlargement in 2 and necessitating an embolization attempt that was unsuccessful in 1 case. No limb occlusion occurred, irrespective of the iliac diameter or angulation.

CONCLUSIONS

Our 1-year results of the Ovation stent-graft system demonstrate excellent safety and effectiveness. The easy navigation through highly angulated and stenosed iliac vessels ensures high technical success in cases of challenging iliac anatomy. Follow-up is ongoing.

Impact of Renal Chimney Grafts on Anatomical Suitability for Endovascular Repair in Ruptured Abdominal Aortic Aneurysm

Purpose: To evaluate the impact of renal chimney grafts on anatomical suitability for endovascular aneurysm repair (EVAR) in ruptured abdominal aortic aneurysm (rAAA). Methods: Contrast-enhanced computed tomography images of 206 patients with rAAA [175 men (mean age 75±7.8 years) and 31 women (mean age of 76±7.5 years)] were evaluated in a dedicated 3-dimensional vascular workstation. Assessment of infrarenal EVAR suitability was based on predefined anatomical variables reflecting the Instructions for Use of commercially available stent-grafts. In patients where aneurysm neck length was the only limiting factor for suitability, reevaluation of the proximal sealing zone was done, accounting for chimney grafts in one or both renal arteries. Results: Seventy (34%) rAAA patients were anatomically suitable for EVAR: 65 (37%) of 175 men and 5 (16%) of 31 women (p<0.01). Eighty-nine (65%) of the 136 unsuitable patients had aneurysm necks <15 mm long; short neck was the only exclusion criterion in 33 (24%) cases. In the 33 short-necked aneurysms without other limiting factors, a proximal sealing zone >15 mm could potentially be achieved with one or two renal chimney grafts in 12 (36%) and 25 (76%) patients, respectively, increasing overall suitability to 40% and 46%. If access issues could also be solved and a similar strategy with chimneys for the renal arteries was applied, the EVAR suitability would increase further to 58%. Conclusion: Roughly one third of patients with rAAA are anatomically suitable for EVAR; short aneurysm neck is the most common exclusion criteria. In appropriate cases, chimney grafts in one or both renal arteries may increase overall suitability by 12%. Suitability increases to ~60% when iliac access issues are additionally overcome.

Ultra-low profile polymer-filled stent graft for abdominal aortic aneurysm treatment: a two-year follow-up

PURPOSE

This study evaluated 2 years of follow-up of the Ovation Abdominal Stent Graft System (TriVascular Inc., Santa Rosa, CA, USA) for endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs).

MATERIALS AND METHODS

This retrospective multicentre study included 36 patients (median age, 73.6 year) with AAAs (mean diameter, 5.65 cm) treated with the Ovation stent graft and followed up for at least 2 years. Safety and effectiveness of the Ovation stent graft were evaluated. Indications for EVAR were the following: AAA ≥5 cm, neck length ≥7 mm, angulation ≤60° and diameter <30 mm; the presence of neck calcification and thrombosis was not considered a contraindication; distal iliac landing zone length of 10 mm, and diameter between 5 and 20 mm. Patients were treated under a common protocol, including clinical and imaging follow-up at discharge, 30 days, 6 months, and annually for 5 years. Adverse events, clinical and imaging data and possible re-intervention were recorded.

RESULTS

The Ovation stent graft was implanted successfully in 36 patients (100 %). None of the patients required conversion to open surgery, and none presented with an aneurysm rupture. Endograft stent fracture or migration was not observed in any case. No type I, III or IV endoleaks were observed; in 12 patients (33.3 %), a type II endoleak was noted, in one case with sac enlargement but not treated due to concomitant comorbidities and the patient's decision.

CONCLUSIONS

The 2-year results of the Ovation Abdominal Stent Graft System demonstrate excellent safety and effectiveness in the treatment of patients with AAAs, particularly in those with challenging anatomical characteristics.

Open vs. endovascular repair of abdominal aortic aneurysm: a comparative analysis

Context:Abdominal aortic aneurysm (AAA) is a condition that is usually asymptomatic, but potentially fatal, and has a prevalence in men over 60 years old ranging from 4.3% to 8%. There are two treatment options available: open surgery (OS) and endovascular treatment (ET).Objective:To compare the results of repairs conducted using these two treatment methods from 2008 to 2013 in a tertiary hospital.Methods:A retrospective analysis comparing 119 patients treated with OS and 219 patients who underwent ET for AAA repair.Results:The ET group was older (71.3 vs. 68.2 years; p<0.001) and had a higher rate of coronary disease (44.7% vs. 27.7%; p=0.002) and a lower ejection fraction (57.6% vs. 64.3%; p<0.001); in turn, the OS group had more chronic obstructive pulmonary disease (16.0% vs. 5.9%; p=0.004) and a smaller proximal infrarenal neck (15.5 mm vs. 23.0 mm; p<0.001). However, there was no difference in ASA classification (American Society of Anesthesiology) (p=0.36). The ET group had less intraoperative bleeding (171 mL vs. 729 mL; p<0.001) and required fewer blood transfusions (11.9% vs. 73.1% p<0.001), and spent shorter stays in both ICU (2.4 vs. 3.5 days; p=0.002) and hospital (5.8 vs. 10.3 days; p<0.001). Thirty-day mortality was similar (OS 5.0% vs. ET 4.1%; p=0.78) and there was also no difference in postoperative complications. The average cost of ET was higher (R$34,277.76 vs. R$4,778.60; p<0.001).Conclusions:Rates of morbidity and mortality were similar, although ET was associated with less bleeding, fewer transfusions and shorter hospital stays, but was more expensive.

Changes in suprarenal and infrarenal aortic angles after endovascular aneurysm repair

Purpose

We investigated whether suprarenal and infrarenal aortic angles change after the endovascular aneurysm repair (EVAR) procedure and during follow-up, and investigated the correlation between infrarenal aortic angle after EVAR and type Ia endoleaks.

Methods

Data collected on 70 EVAR procedures for a fusiform infrarenal aortic aneurysm performed between May 2006 and December 2012 were supplemented with a retrospective review of charts and radiographs.

Results

The greater the preoperative infrarenal aortic angle, the greater the suprarenal aortic angle (r = 0.72, P < 0.001). The infrarenal aortic angle decreased after the EVAR procedure and continued to decrease slowly thereafter (all P < 0.001). Suprarenal aortic angle decreased immediately after the EVAR procedure and continued to decrease during the first month (P < 0.001). No differences in angulation were observed based on stent graft type. Type Ia endoleaks occurred with significantly greater incidence in patients with a larger post EVAR infrarenal angle (P = 0.037).

Conclusion

The infrarenal aortic angle decreased significantly immediately after the EVAR procedure and continued to decrease slowly thereafter. Suprarenal aortic angle decreased immediately after the EVAR procedure and continued to decrease during the first month. We found a correlation between infrarenal and suprarenal aortic angle. Type Ia endoleaks occurred with greater incidence in patients with a larger infrarenal angle immediately after EVAR.

Impact of gender and body surface area on outcome after abdominal aortic aneurysm repair

BACKGROUND

A gender-neutral threshold aneurysm diameter (AD) of more than 5.5 cm for surgical intervention in abdominal aortic aneurysms (AAA) ignores the fact that women have a smaller baseline AD. We hypothesized that women have a greater AD relative to body surface area (BSA) at the time of surgery and that this worsens outcome.

METHODS

The Vascular Study Group of New England database was queried for elective AAA repairs performed from 2003 to 2011 to compare BSA-indexed AD, ie, aortic size index (ASI), between men and women at the time of surgery and the impact of ASI on outcome.

RESULTS

Women were older and had higher ASI among both open-repair (n = 1,566) and endovascular repair (n = 2,172) patients (P < .001). Among open-repair patients, mean ASI for men undergoing repair at AD of 5.5 cm (2.75 cm/m²) was used to subdivide women into 2 categories: women with ASI of 2.75 or more were older (P < .001), had a larger aneurysm size (P < .001), and had a higher 1-year mortality (P = .042) than women with ASI less than 2.75.

CONCLUSIONS

When indexed to BSA, women have a larger aneurysm size than men at the time of AAA repair.

Mini-invasive aortic surgery: personal experience

OBJECTIVE

In this study, we retrospectively evaluated our experience in minilaparotomy (MINI) and compared the results with conventional open repair (OPEN).

METHODS

From January 2005 to December 2012, we surgically treated 234 consecutive patients with elective infrarenal abdominal aortic aneurysms, 195 men and 39 women, with a mean age of 74 years. Inclusion criteria for MINI were not ruptured abdominal aortic aneurysm, increased surgical risk, anatomical limits for endovascular repair, no previous surgical invasion of the abdominal cavity, and no requirement for concomitant abdominal surgical invasion. Surgical treatment was OPEN in 113 patients (48.3%) and MINI through an 8- to 14-cm incision in 121 patients (51.7%). Epidural anesthesia has been added in 26.5% and in 19.3% of the MINI and OPEN patients, respectively. Mortality, complications, aortic clamping time, operative time, need for postoperative morphine therapy, time to solid diet, and length of hospital stay were registered.

RESULTS

The MINI has been performed in all patients selected, with 72 aortoaortic grafts and 49 aortobisiliac grafts. Early mortality was 1.6% versus 3.5% (P > 0.5); 1-, 3-, and 5-year mortality were 7% versus 9%, 19% versus 22%, and 29% versus 34% (P > 0.5); complications were 12.2% versus 26.6% (P > 0.05); mean (SD) clamping time was 48 (12) versus 44 (14) minutes (P > 0.5); mean (SD) operative time was 218.72 (41.95) versus 191.44 (21.73) minutes (P > 0.025); mean (SD) estimated intraoperative blood loss was 425.64 (85.95) versus 385.30 (72.41) mL (P > 0.1); mean (SD) morphine consumption in the group given epidural and the group not given epidural was 0 (2) and 2 (2) mg intravenously (IV) versus 2 (4) (P < 0.5) and 4 (3) mg IV (P > 0.1); mean (SD) ambulation was 2.1 (0.6) versus 4.1 (2.7) (P < 0.5); mean (SD) time to solid diet was 2.1 (0.4) versus 3.5 (1.6) (P < 0.5); and mean (SD) length of hospital stay was 4.9 (1.64) versus 7.35 (1.95) days (P > 0.05), in the MINI and OPEN groups, respectively. Postoperative hernia at 3 years was 18% versus 23% in the MINI and OPEN groups (P < 0.5), respectively.

CONCLUSIONS

The MINI gives the patients a significantly shorter period of recovery with the quality and safety of the OPEN. This experience suggested extending the indication to all surgical candidates without local limitations.

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.