Outcome of endovascular abdominal aortic aneurysm repair in patients with conditions considered unfit for an open procedure: a report on the EUROSTAR experience

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.

Transrenal Endovascular Aneurysm Repair-A Novel Approach for Abdominal Aortic Aneurysms with Difficult Neck Anatomy

BACKGROUND

The endovascular approach to treating ruptured or symptomatic abdominal aortic aneurysms (AAAs) with difficult neck anatomy still poses a major challenge. This study proposes and evaluates the outcomes of a novel technique, Transrenal Endovascular Aneurysm Repair (Tr-EVAR) which utilizes the top ring 'valley' and 'peak' configuration of the Anaconda stent graft to achieve proximal seal in AAAs with an unfavourable neck.

METHODS

All patients treated with Tr-EVAR over a period of 10 years were identified retrospectively. Demographic, clinical and outcome data were collected, and survival analysis was performed. The time-to-event was analyzed using Kaplan-Meier curves for complication-free survival, reintervention-free survival, and overall survival.

RESULTS

During the study period, 36 patients ruptured, symptomatic or large AAAs having unfavorable necks and not fit for open repair underwent Tr-EVAR. Two patients died in the first 30 days postprocedure (5.6%). The overall survival at 1 year, 3 years and 5 years were 86%, 72% and 54% respectively with a mean overall survival of 74.0 months (SE 7.8, 95% confidence interval 58.7-89.3) which was comparable to chimney endovascular aneurysm repair (EVAR). The complication-free survival and reintervention-free survival at 1 year, 3 years, and 5 years were 75%, 61%, 42%, 78%, 64%, and 45%, respectively.

CONCLUSIONS

Tr-EVAR can be considered as an off-the-shelf solution for urgent cases not fit for open repair with unfavourable neck features for standard EVAR. Careful patient selection and planning have generated acceptable immediate, midterm and long-term results comparable to those presented by chimney EVAR in the literature.

Randomized Controlled Trial of Oral Tranexamic Acid Intervention for the Prevention of Type II Endoleak after Endovascular Abdominal Aneurysm Repair

Purpose: The purpose of this study was to evaluate tranexamic acid (TA) for the prevention of type II endoleak (EL2) at a high level of evidence by a randomized controlled trial.

Methods: Patients who underwent endovascular aneurysm repair (EVAR) between May 2017 and January 2020 were included. Patients in the TA group were given 750 mg of TA daily for a month after EVAR. The incidence of EL2, blood coagulation/fibrinolytic ability, and changes in aneurysm diameter were compared between two groups.

Result: On the 7th day after EVAR, EL2 was found in 14 patients (34.1%) in the TA group and in 7 patients (15.9%) in the non-TA group. It was also found in 12 patients (29.3%) in the TA group and 6 patients (13.6%) in the non-TA group at 1 month after EVAR. There was no significant difference in the incidence of EL2 between the two groups (p = 0.051, 0.08). Blood tests revealed that fibrin degradation product and D-dimer were significantly suppressed in the TA group, there was no significant difference in the change of diameter regardless of the TA intake.

Conclusion: This study proved anti-fibrinolytic effect of the TA, but it alone had not enough power to decrease EL2 after EVAR.

[18F] FDG PET/CT can improve the diagnostic accuracy for aortic endograft infection

PURPOSE

Aortic endograft infection (EI) can result in potentially life-threatening vascular complications. Unfortunately, it is difficult to obtain a correct diagnosis at an early stage in many patients. This report aims at validating the use of [¹⁸F] FDG PET/CT imaging for suspected endograft infections in a prospectively collected cohort of patients treated with EVAR and TEVAR.

MATERIALS AND METHODS

During a 14-year period, 366 patients required aortic stent graft. All procedures were performed electively, except for one patient. Among these 366 patients, eleven patients (3%) were suspected to have aortic EI. Contrast-enhanced CT and FDG PET/CT were performed in all 11 patients. Medical charts and imaging were analysed for these 11 cases, with initial positive CT.

RESULTS

The final diagnosis of EI was established in seven (1,9%) based on clinical features, laboratory investigations and a significant [¹⁸F] FDG uptake in the aortic graft as well as the aortic wall. The median time from the initial EVAR/TEVAR to diagnosed infection was 180 days. During follow-up, the seven patients had a second PET/CT that was compared with the initial evaluation, decreased uptake was correlated with clinical improvement.

CONCLUSIONS

Contemporary diagnostic imaging for a potentially lethal endograft infection lacks precision, this observational study illustrates the potential clinical value of [¹⁸F] FDG PET/CT in the management of aortic EI. [¹⁸F] FDG PET/CT constitutes an imaging modality able to confirm the diagnosis, monitor disease progression as well as the effect of pharmaceutical treatment and detect relapse.

Outcomes of Elective Endovascular Aneurysmal Repair for Abdominal Aortic Aneurysms in Jordan

Purpose

The outcomes of endovascular aneurysmal repair (EVAR) for infrarenal abdominal aortic aneurysms (AAAs) in the Middle East have rarely been reported. We analyzed the outcomes of EVAR in a Jordanian population.

Materials and Methods

We conducted a retrospective review of the medical records of patients with infrarenal AAA who were treated with elective EVAR between January 2004 and January 2017 at a single center in Jordan. Patient characteristics, anatomical characteristics, procedural details, and early and late postoperative outcomes were analyzed.

Results

A total of 288 patients (mean age, 70 years; 77.8% males) underwent EVAR for infrarenal AAA (median aneurysm size, 64 mm). Bifurcated endografts were used in 265 patients, and aorto-uni-iliac devices were used in 22 patients. Successful endograft deployment was achieved in all patients with no open conversion. Early complications included localized groin hematoma in 15, femoral artery dissection in 4, wound infection in 3, and seroma in 3 patients. With a mean follow-up of 60 months, 50 endoleaks were detected, including 9 type I, 38 type II, and 3 type III. Seven patients had unilateral graft limb occlusion. The 30-day mortality was 1.7%, and long-term mortality was 7.0%, mostly due to non-AAA-related causes.

Conclusion

EVAR was safely performed in Jordanian patients with minimal complications. However, long-term surveillance is important due to the risk of endoleaks and consequent intervention.

Long-term survival following successful abdominal aortic aneurysm repair evaluated using Australian administrative data

BACKGROUND

Long-term survival (LTS) following abdominal aortic aneurysm (AAA) surgery is an outcome that can compare open surgical repair (OSR) and endovascular AAA repair (EVAR) methods. We examined the LTS of persons following successful AAA repair using administrative health data covering the Australian Pharmaceutical Benefits and Medicare Benefits Schemes from 1993 to 2014.

METHODS

Participants undergoing AAA surgery were identified using procedure codes and the last service provision date used as a proxy mortality marker. LTS and relative survival with control populations in those who survived the initial post-operative period were used to compare OSR and EVAR and estimates between the first and second halves of the study.

RESULTS

A total of 2060 persons who had undergone AAA repair were identified. Overall median LTS (95% CI) following elective, ruptured OSR and EVAR were 10.4 (9.1-11.0), 8.5 (6.7-10.3) and 9.7 (8.1-11.3) years, respectively. Relative survival rates at 5 and 10 years were 0.89 and 0.7 for OSR and 0.87 and 0.66 for EVAR. LTS rates were similar for OSR and EVAR in age groups 65-84 years (EVAR/OSR range 0.96-1.16); however, EVAR was superior to OSR in persons aged >85 years at 5 years (EVAR/OSR 1.32, log-rank P < 0.05). Relative survival following all techniques of AAA repair showed no significant change over the duration of the study.

CONCLUSION

LTS following AAA repair was heterogeneous in comparison with control populations and varied with age and procedure. The 5-year LTS following EVAR in persons aged >85 years is superior to OSR. Administrative data can define long-term outcomes following aortic aneurysm surgery and may complement data already collected by surgeons.

Explant of aortic stent grafts following endovascular aneurysm repair

Background

Failure of endovascular aneurysm repair may require explant of the stent graft in a subset of patients. We sought to assess outcomes in a cohort of patients undergoing explant of endovascular aneurysm repair in both emergency and elective settings.

Methods

Patients undergoing explant of endovascular aneurysm repair were identified from a prospectively maintained database, with additional information obtained through retrospective analysis of medical records.

Results

Over a 21-year period, 1997–2018 (May), there were 597 endovascular aneurysm repair procedures performed in our institution for abdominal aortic aneurysm. There were 19 endovascular aneurysm repair explants; five of these were referrals from other vascular centres. The median age was 73 years (range 46–81). The median length of time from insertion to explant was 39.2 months (range 0–153). Indications for elective explant were type Ia endoleak (n = 4), type 1b endoleak (n = 1), type II endoleak with increasing sac size (n = 1), type I/III endoleak (n = 1), type IV endoleak (n = 1), and increasing sac size without evident endoleak (type V, n = 2). The remaining nine cases were emergency procedures, with four patients presenting with rupture post endovascular aneurysm repair, four patients presenting with acute stent thrombosis, of which one also had a type 1a endoleak and one aorto-enteric fistula. There were no mortalities in the elective group and three mortalities in the emergency group (0 vs 33.3%, p = 0.087). Overall 30-day mortality was 15.8%

Conclusion

Explant of aortic stent grafts can be associated with high mortality and morbidity rates, especially in the emergent setting. Patient and device selection and post-operative surveillance remain vitally important to optimise outcomes post endovascular aneurysm repair.

Late Survival in Nonoperated Patients with Infrarenal Abdominal Aortic Aneurysm

OBJECTIVE/BACKGROUND

Historical studies report high rupture rates in patients with nonoperated abdominal aortic aneurysms (AAAs) of > 5.5 cm diameter, although a recent audit has questioned this.

METHODS

This was a retrospective review of 138/764 (18%) patients with AAAs evaluated in a preassessment anaesthetic clinic (PAC) between 2006 and 2012, who either did not undergo elective AAA repair or who underwent deferred repair. The remaining 626 underwent repair. Patients with severe comorbidities (dementia, advanced malignancy, life-expectancy < 1 year) and not referred to PAC were excluded.

RESULTS

At a median of 27 months, 71 (52%) died, 36 (51%) following rupture. Cumulative survival, free from rupture or surgery for acute symptoms, was 96% at 1 year, 84% at 3 years, and 64% at 5 years, where baseline AAA diameters were 5.5-6.9 cm. For diameters ≥ 7 cm, survival, free from rupture, was 65% at 1 year, 29% at 3 years, and 0% at 5 years. Median interval to rupture was 47 months (AAA diameter 5.5-6.9 cm) and 21 months where baseline diameters were ≥ 7 cm. Rupture accounted for 32% of late deaths in patients with AAAs of 5.5-5.9 cm diameter, 46% in those with AAAs measuring 6.0-6.9 cm in diameter, and 71% in patients with AAA measuring ≥ 7 cm in diameter.

CONCLUSION

Approximately half of all late deaths in this nonoperated cohort were not AAA related, suggesting that even had repair been undertaken, it would not have prolonged patient survival. The incidence of rupture in "high-risk" patients with an AAA < 7 cm diameter was < 5% at 1 year, thereby giving ample time to optimise risk factors and improve pre-existing medical conditions prior to undertaking a deferred intervention. Even if these patients did not undergo surgical repair, the risk of late rupture was relatively low. By contrast, nonoperated patients with AAAs ≥ 7 cm in diameter face a very high risk of rupture and will probably benefit from elective surgery, with the caveat that a higher procedural risk might have to be incurred.

Natural History of the Iliac Arteries after Endovascular Abdominal Aortic Aneurysm Repair and Suitability of Ectatic Iliac Arteries as a Distal Sealing Zone

Purpose:

To investigate the natural history of dilated common iliac arteries (CIA) exposed to pulsatile blood flow after endovascular abdominal aortic aneurysm repair (EVAR) and the suitability of ectatic iliac arteries as sealing zones using flared iliac limbs.

Methods:

Follow-up computed tomograms of 102 CIAs in 60 EVAR patients were investigated. Diameter changes in CIAs ≤16 mm (group 1) were compared with changes in vessels where a dilated segment >16 mm in diameter continued to be exposed to pulsatile blood flow (group 2). Within group 2, cases in which the stent terminated proximal to the dilated artery segment (2a) were compared with those that had been treated with a flared limb (2b).

Results:

The mean CIA diameter increased by 1.0±1.0 mm in group 1 (p<0.001 versus immediately after EVAR) and by 1.5±1.7 mm in group 2 (p<0.001 versus immediately after EVAR) within an average follow-up of 43.6±18.0 months. Diameter increase was more pronounced in dilated CIAs (p=0.048), and it was not significantly different between groups 2a and 2b (p=0.188). No late distal type I endoleak or stent-graft migration associated with CIA ectasia was observed.

Conclusion:

Dilatation of the CIA is significant after EVAR, and it is more pronounced in ectatic iliac arteries. Although ectatic iliac arteries appear to be suitable sealing zones in the short term, continued follow-up is mandatory.

Emergency Endovascular Stent Grafting for Thoracic Aortic Pathology

Our aim was to report single-center results of emergency endovascular treatment for thoracic aortic disease.

From March 1998 to January 2006, 30 acute thoracic EVAR procedures were carried out in 29 patients. One patient received two procedures in different settings. Four patients died before treatment could be initiated. The pathology of aortic lesions included atherosclerotic aneurysm ( n = 13), pseudoaneurysm ( n = 6), aortic rupture ( n = 5), type B dissection ( n = 5), aortobronchial or aortoesophageal fistula ( n = 4), and intramural hematoma ( n = 1).

The surgical mortality rate was 21%. Three patients died as a result of technical complications, and three patients died after technically successful procedures.

The mean follow-up was 31 ± 23 months. The late mortality rate was 40% (8 of 20). Four patients died of causes unrelated to the procedure; two patients died at home without autopsy. Two patients died as a consequence of graft infections.

Three late nonfatal complications occurred. Two of these resulted in additional treatment: one patient developed a mycotic aneurysm that was treated with additional stent grafting, and one patient developed a type 3 endoleak after 6 years of follow-up and was successfully treated with a bridging stent graft.

Endovascular treatment for acute thoracic disease is feasible and associated with a reasonable outcome. In selected cases, it may be considered as a first option.

Paravertebral Blockade with Propofol Sedation versus General Anesthesia for Elective Endovascular Abdominal Aortic Aneurysm Repair

The objective of this study was to evaluate the applicability of paravertebral blockade (PVB) for endovascular abdominal aortic aneurysm repair compared with general anesthesia (GA).

Data from patients who underwent elective infrarenal endovascular abdominal aortic aneurysm repair between August 2001 and July 2002 using PVB or GA were retrospectively reviewed and compared with respect to risk factors, intraoperative hemodynamic characteristics, operative outcome, and complications.

Ten patients underwent elective infrarenal endovascular abdominal aortic aneurysm repair under PVB, whereas 15 patients were operated on under GA. One conversion from PVB to GA was necessary for block failure. The perioperative (< 30 days) cardiovascular morbidity and overall mortality were zero in both groups. The PVB group benefited significantly with respect to the incidence of intraoperative hypotension ( p < .05) and blood pressure lability ( p < .01), as well as postoperative nausea ( p < .01). Our preliminary results indicate that PVB is feasible and can be performed safely in a patient population with significant comorbidities.

Ten-Year Outcomes after Endovascular Aneurysm Repair (Evar) and Magnitude of Additional Procedures

Background and Aims:

With any new technology complications are possible, and problems with first-generation aortic stentgrafts have been extensively reported. The long-term outcome of this patient population and the magnitude of additional secondary procedures are, however, less well covered.

Materials and Methods:

Between February 1997 and November 1999, 48 patients (44 men and 4 women; mean age 70 years; range 54–85) with AAA (average 57mm, range 40–90mm) were treated with a Vanguard® endoprosthesis. Stentgrafts were sized by CT and angiography-based measurements. Results were continuously assessed using contrast-enhanced CT before discharge, 1, 3, 6 and 12 months after the procedure and thereafter annually. Since 2001 plain abdominal X-rays have been performed annually.

Results:

The technical implant success rate was 100%. Median follow-up was 91 months (range 7.6–120 months). None of the patients was lost during this period. Hospital mortality was 0%. There were 25 subsequent deaths (52%), the most common cause being coronary artery disease. There were ten late conversions to open surgical repair, including three emergency operations: two due to rupture and one to thrombosis. EVAR-related complications were encountered in 43 patients (90%): 12 primary endoleaks (all type II), 36 late endoleaks (16 type I, 2 type II and 18 type III), 22 migrations, 25 row separations, 20 thromboses, one endotension and 3 ruptures of the AAA. Secondary procedures were required in 39 patients (81%): 1 re-endografting by aortoiliac bifurcated graft and 3 with a uni-iliac graft; 33 limb graft repairs were performed and 19 infrarenal cuffs were placed. There were 4 late embolizations and 4 attempts, and 6 thrombolyses, four of which were successful. Further, 9 femoro-femoral crossover by-pass and 2 axillo-femoral by-pass operations and 2 amputations were carried out during the follow-up. Only one patient was alive without complications.

Conclusions:

The impact of long-term follow-up of patients treated with the new technology was emphasized in this patient population. A careful surveillance protocol and active endovascular treatment of complications can yield acceptable results and low AAA rupture and aneurysm mortality rates, also with the first-generation endovascular graft. A new technology, however, may involve unpredictable problems which can magnify the workload and incur high costs over several years after the initial procedure.

Contrast-enhanced ultrasound after endovascular aortic repair-current status and future perspectives

An increasing number of patients with abdominal aortic aneurysms (AAAs) are undergoing endovascular aortic repair (EVAR) instead of open surgery. These patients require lifelong surveillance, and the follow-up imaging modality of choice has been traditionally computed tomography angiography (CTA). Repetitive CTA imaging is associated with cumulative radiation exposure and requires the administration of multiple doses of nephrotoxic contrast agents. Contrast-enhanced ultrasound (CEUS) has emerged as an alternative strategy in the follow-up of patients with EVAR and demonstrates high sensitivity and specificity for detection of endoleaks. In fact, a series of studies have shown that CEUS is at least performing equal to computed tomography for the detection and classification of endoleaks. This article summarizes current evidence of CEUS after EVAR and demonstrates its usefulness via various patient cases.

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.

APC-PCI complex levels for screening of AAA in patients with peripheral atherosclerosis

To evaluate the use of activated protein C-protein C inhibitor (APC-PCI) complex levels for detection of abdominal aortic aneurysm (AAA) in patients with peripheral atherosclerotic disease (PAD). APC-PCI levels and aortic diameter evaluated in 511 PAD patients without previously known AAA followed-up concerning survival for 4.8(0.5) years. AAA was found in 13% of patients. Aortic diameter correlated (r = 0.138; p = 0.002) with APC-PCI levels which were higher (0.40[0.45] vs. 0.30[0.49] μg/l; p = 0.004) in patients with AAA. This difference persisted in multivariate analysis (p = 0.029). A threshold value of APC-PCI ≥0.15 μg/L showed a specificity of 11%, a sensitivity of 97% and a negative predictive value of 96% for an AAA diagnosis. APC-PCI levels were higher in patients with AAA, and showed high sensitivity but low specificity for the diagnosis and can therefore not be considered as a screening tool in PAD patients. An AAA prevalence of 13% in patients with PAD indicates a need for AAA screening within this population.

Management of aortoiliac aneurysms by retrograde endovascular hypogastric artery preservation

We evaluated the outcome of the retrograde endovascular hypogastric artery preservation (REHAP) technique for the treatment of complex aortoiliac aneurysms (AIAs). Perioperative and long-term outcomes were assessed for 12 patients (mean age 77 years, range 64-86 years) who underwent elective endovascular AIA repair via aortouniiliac endografting and REHAP between January 2004 and January 2011. Preoperative images obtained by computed tomography were used for planning. Postoperative images were obtained one and six months after surgery, and once a year thereafter. Technical success was achieved in all cases. No patients exhibited endoleak related to the endoprosthesis, occlusion of implanted components, hip and/or buttock claudication, or colon or spinal cord ischemia during follow-up. This hybrid procedure illustrates the potential of REHAP in the treatment of AIA cases.

Clinical outcomes for hostile versus favorable aortic neck anatomy in endovascular aortic aneurysm repair using modular devices

BACKGROUND

Endovascular aneurysm repair (EVAR) is not generally recommended for patients with hostile neck anatomy. This study analyzed the clinical implications of various clinical features of proximal aortic neck anatomy.

METHODS

Prospectively collected data from 258 EVAR patients using modular devices were analyzed. Patients were classified as having favorable neck anatomy (FNA) or hostile neck anatomy (HNA). HNA was defined as any or all of length of <10 mm, angle of >60°, diameter of >28 mm, ≥50% circumferential thrombus, ≥50% calcified neck, and reverse taper. Univariate, multivariate, and Kaplan-Meier analyses were used to compare early and late clinical outcomes.

RESULTS

FNA was present in 37% and HNA was present in 63%. Clinical and demographic characteristics were comparable. Technical success was 99%. Mean follow-up was 22 months (range, 1-78 months). Perioperative complication rates were 3% for FNA vs 16% for HNA (P = .0027). Perioperative deaths were 0% for FNA and 3% for HNA (P = .2997). Proximal type I early endoleaks (intraoperative) occurred in 9% of FNA vs 22% for HNA (P = .0202). Intraoperative proximal aortic cuffs were used to seal endoleaks in 9% of FNA vs 22% of HNA (P = .0093). At late follow-up, abdominal aortic aneurysm expansion was noted in 6% of FNA vs 7% of HNA (P = .8509). Rates of freedom from late type I endoleaks at 1, 2, 3, and 4 years were 97%, 97%, 97%, and 90% for FNA vs 89%, 89%, 89%, and 89% for HNA (P = .1224); rates for late interventions were 95%, 90%, 90%, and 90% for FNA vs 95%, 93%, 91%, and 85% for HNA (P = .6902). Graft patency at 1, 2, and 3 years was 99%, 99%, and 99% for FNA vs 97%, 92%, and 90% for HNA (P = .0925). The survival rates were 93%, 84%, 76%, and 76% for FNA vs 88%, 82%, 74%, and 66% for HNA (P = .2631). Reverse taper was a significant predictor for early type I endoleak (odds ratio [OR], 5.25, P < .0001), reverse taper (OR, 5.95; P < .0001) and neck length (OR, 4.15; P = .0146) were for aortic cuff use; circumferential thrombus (OR, 2.44; P = .0448), and neck angle (OR, 3.38; P = .009) were for perioperative complications.

CONCLUSIONS

Patients with HNA can be treated with EVAR, but with higher rates of early (intraoperative) type I endoleak and intervention. The midterm outcomes are similar to FNA.

Thoracic Endograft for Abdominal Aortic Aneurysms, an Unusual Application for Severe Neck Angulation: Case Report and Literature Review

Our goal was to achieve complete proximal sealing in severe aortic neck angulation (SNA) during endovascular aneurysm repair (EVAR) of a patient with an abdominal aortic aneurysm (AAA) unfit for surgery. An 82-year-old patient with an infrarenal AAA of 9.8 cm with an SNA of 90° was admitted for acute coronary syndrome. Following coronary treatment, the patient was considered unfit for surgery and therefore was evaluated for EVAR. Aneurysm sac exclusion was obtained with the deployment of a Powerlink bifurcated graft (Endologix Inc, Irvine, CA) inside a Relay thoracic endograft (Bolton Medical, Florida) placed just below the most distal renal artery. At 6 months, computed tomographic angiography confirmed correct graft placement, complete aneurysm exclusion, and a reduction in the aneurysmal sac. In AAA patients with an SNA at high risk of EVAR failure, the adaptability of a thoracic endograft could be considered for proximal sealing.

Computed tomography virtual intravascular endoscopy in the evaluation of fenestrated stent graft repair of abdominal aortic aneurysms

BACKGROUND

This study aimed to investigate the diagnostic value of computed tomography virtual intravascular endoscopy (VIE) in the follow-up of patients with abdominal aortic aneurysm (AAA) treated with fenestrated stent grafts.

METHODS

A total of 19 patients (17 males and 2 females; mean age: 75 years) with AAA undergoing fenestrated stent grafts were retrospectively studied. Pre- and post-fenestration computed tomography data were reconstructed for the generation of VIE images of aortic ostia and fenestrated stents and compared with two-dimensional axial and multiplanar reformation (MPR) images. Serum creatinine was measured pre and post fenestration to evaluate the renal function.

RESULTS

The mean intra-aortic length measured by VIE, two-dimensional axial and MPR were 4.7, 4.4 and 4.6 mm, respectively, for the right renal stent; 5.0, 4.9 and 5.0 mm, respectively, for the left renal stent; and 5.9, 6.0 and 6.0 mm, respectively, for the superior mesenteric artery stent. Comparisons of these measurements did not show significant difference (P > 0.05). The mean diameters of renal artery ostia measured on VIE visualization pre and post fenestration were 9.2 x 8.3 and 10 x 8.9 mm for the right renal ostium; 8.3 x 7.1 and 9.9 x 8.9 mm for the left renal ostium, with significant changes observed (P < 0.01). No renal dysfunction was observed in this group.

CONCLUSION

VIE is a valuable visualization tool in the follow-up of fenestrated stent graft repair of AAA by providing intraluminal appearance of fenestrated stents and measuring the length of stent protrusion.

Analysis of outcome after using high-risk criteria selection to surgery versus endovascular repair in the modern era of abdominal aortic aneurysm treatment

INTRODUCTION

The concept of high-risk patients suggests that such patients will experience a higher rate of postoperative complications and worse short- and long-term outcomes, and should therefore benefit from the use of endovascular techniques for aortic abdominal aneurysm (AAA) repair. The primary goal of this study was to assess the relevance of the different high-risk criteria, defined by the French health agency Agence Française de Sécurité Sanitaire des Produits de Santé (AFSSAPS) in a single-centre continuous series. Secondary goals were to retrospectively compare the incidence of postoperative complications and short- and long-term survival in three groups of patients.

MATERIALS AND METHODS

Between January 1999 and December 2006, details of all the patients undergoing elective surgery for AAA in our hospital were recorded into a prospective registry (n=626). Three groups were considered according to the level of risk and type of repair defined by the AFSSAPS: endovascular aortic aneurysm repair (EVAR) high-risk (HR) (at least one high-risk factor and EVAR, n=138), open HR (at least one high-risk factor and open repair, n=134) and open low-risk (LR) (no high-risk factors and open repair, n=344). None of the low-risk patients were treated using an endovascular approach. The demographics, preoperative risk factors, intra-, postoperative data and short- and long-term survival were compared between the groups. Interrelations among the set of high-risk criteria for mortality were calculated using multiple correspondence analysis (MCA).

RESULTS

The distribution of high-risk criteria was similar in both high-risk groups, except for age, heart failure and hostile abdomen, which were significantly more frequent in EVAR HR. Operation time, blood loss and length of stay in an intensive care unit and hospital were significantly lower in the EVAR HR group. The 30-day mortality and survival rates at 5 years were 5.4 and 59.4% for EVAR HR, 3.7 and 70.4% for open HR and 2.3 and 83.7% for open LR, respectively, with no significant difference between the three groups for the mortality, but a significant higher survival at 5 years for the open LR versus both high-risk groups.

CONCLUSION

The high-risk AFSSAPS criteria were not predictive of postoperative mortality and should not be used to determine the choice of treatment technique. Other criteria therefore need to be established to determine whether open or EVAR repair should be used.

Endovascular stent graft repair of abdominal aortic aneurysms: Current status and future directions

Endovascular stent graft repair of abdominal aortic aneurysm (AAA) has undergone rapid developments since it was introduced in the early 1990s. Two main types of aortic stent grafts have been developed and are currently being used in clinical practice to deal with patients with complicated or unsuitable aneurysm necks, namely, suprarenal and fenestrated stent grafts. Helical computed tomography angiography has been widely recognized as the method of choice for both pre-operative planning and post-operative follow-up of endovascular repair (EVAR). In addition to 2D axial images, a number of 2D and 3D reconstructions are generated to provide additional information about imaging of the stent grafts in relation to the aortic aneurysm diameter and extent, encroachment of stent wires to the renal artery ostium and position of the fenestrated vessel stents. The purpose of this article is to provide an overview of applications of EVAR of AAA and diagnostic applications of 2D and 3D image visualizations in the assessment of treatment outcomes of EVAR. Interference of stent wires with renal blood flow from the hemodynamic point of view will also be discussed, and future directions explored.

Fenestrated stent graft repair of abdominal aortic aneurysm: hemodynamic analysis of the effect of fenestrated stents on the renal arteries

Objective

We wanted to investigate the hemodynamic effect of fenestrated stents on the renal arteries with using a fluid structure interaction method.

Materials and Methods

Two representative patients who each had abdominal aortic aneurysm that was treated with fenestrated stent grafts were selected for the study. 3D realistic aorta models for the main artery branches and aneurysm were generated based on the multislice CT scans from two patients with different aortic geometries. The simulated fenestrated stents were designed and modelled based on the 3D intraluminal appearance, and these were placed inside the renal artery with an intra-aortic protrusion of 5.0-7.0 mm to reflect the actual patients' treatment. The stent wire thickness was simulated with a diameter of 0.4 mm and hemodynamic analysis was performed at different cardiac cycles.

Results

Our results showed that the effect of the fenestrated stent wires on the renal blood flow was minimal because the flow velocity was not significantly affected when compared to that calculated at pre-stent graft implantation, and this was despite the presence of recirculation patterns at the proximal part of the renal arteries. The wall pressure was found to be significantly decreased after fenestration, yet no significant change of the wall shear stress was noticed at post-fenestration, although the wall shear stress was shown to decrease slightly at the proximal aneurysm necks.

Conclusion

Our analysis demonstrates that the hemodynamic effect of fenestrated renal stents on the renal arteries is insignificant. Further studies are needed to investigate the effect of different lengths of stent protrusion with variable stent thicknesses on the renal blood flow, and this is valuable for understanding the long-term outcomes of fenestrated repair.

Endovascular treatment of peripheral vascular disease

Peripheral arterial disease (PAD) affects about 27 million people in North America and Europe, accounting for up to 413,000 hospitalizations per year with 88,000 hospitalizations involving the lower extremities and 28,000 involving embolectomy or thrombectomy of lower limb arteries. Many patients are asymptomatic and, among symptomatic patients, atypical symptoms are more common than classic claudication. Peripheral arterial disease also correlates strongly with risk of major cardiovascular events, and patients with PAD have a high prevalence of coexistent coronary and cerebrovascular disease. Because the prevalence of PAD increases progressively with age, PAD is a growing clinical problem due to the increasingly aged population in the United States and other developed countries. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, endovascular practice, percutaneous transluminal angioplasty with or without stenting, is used far more frequently for all types of lower extremity occlusive lesions, reflecting the continuing advances in imaging techniques, angioplasty equipment, and endovascular expertise. The role of endovascular intervention in the treatment of limb-threatening ischemia is also expanding, and its promise of limb salvage and symptom relief with reduced morbidity and mortality makes percutaneous transluminal angioplasty/stenting an attractive alternative to surgery and, as most endovascular interventions are performed on an outpatient basis, hospital costs are cut considerably. In this monograph we discuss current endovascular intervention for treatment of occlusive PAD, aneurysmal arterial disease, and venous occlusive disease.

Patients with Abdominal Aortic Aneurysm and Chronic Obstructive Pulmonary Disease Have Improved Outcomes with Endovascular Aneurysm Repair Compared with Open Repair

The purpose of our study was to evaluate outcomes in abdominal aortic aneurysm (AAA) patients with chronic obstructive pulmonary disease (COPD) undergoing open or endovascular abdominal aortic aneurysm repair (EVAR). We retrospectively examined the records of consecutive patients with AAA and COPD who underwent either open repair or EVAR between 2001 and 2008. In-hospital and follow-up outcomes were compared between open repair and EVAR using SPSS (SPSS Inc, Chicago, IL). Sixty-nine patients were included for analysis (mean age 71 ± 1.0 years; 93% [ n = 64] male). Open surgery was performed in 63% ( n = 43). In-hospital mortality was 4%. All-cause mortality did not differ significantly between the open repair and EVAR groups during 3 years of follow-up ( p = .491). In-hospital death and major complications occurred in 30% ( n = 13) after open repair compared with 12% ( n = 3) after EVAR ( p = .075). Pneumonia occurred in 19% ( n = 8) after open repair and in 0% after EVAR ( p = .019); pneumonia was associated with increased mortality during the first year after AAA repair (log-rank test p = .003). Hospital length of stay was increased in the open repair group compared with the EVAR group (16 vs 5 days, p < .001), as was intensive care unit length of stay (11 vs 2 days, p < .001) and need for ventilation (61% vs 12%, p < .001). Patients with COPD and anatomically suitable AAAs should be preferentially offered EVAR.

Defining high-risk patients for endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm repair (EVAR) is commonly used as a minimally invasive technique for repairing infrarenal aortic aneurysms. There have been recent concerns that a subset of high-risk patients experience unfavorable outcomes with this intervention. To determine whether such a high-risk cohort exists and to identify the characteristics of these patients, we analyzed the outcomes of Medicare patients treated with EVAR from 2000-2006.

METHODS

We identified 66,943 patients who underwent EVAR from Inpatient Medicare database. The overall 30-day mortality was 1.6%. A risk model for perioperative mortality was developed by randomly selecting 44,630 patients; the other one third of the dataset was used to validate the model. The model was deemed reliable (Hosmer-Lemeshow statistics were P = .25 for the development, P = .24 for the validation model) and accurate (c = 0.735 and c = 0.731 for the development and the validation model, respectively).

RESULTS

In our scoring system, where scores ranged between 1 and 7, the following were identified as significant baseline factors that predict mortality: renal failure with dialysis (score = 7); renal failure without dialysis (score = 3); clinically significant lower extremity ischemia (score = 5); patient age >or=85 years (score = 3), 75-84 years (score = 2), 70-74 years (score = 1); heart failure (score = 3); chronic liver disease (score = 3); female gender (score = 2); neurological disorders (score = 2); chronic pulmonary disease (score = 2); surgeon experience in EVAR <3 procedures (score = 1); and hospital annual volume in EVAR <7 procedures (score = 1). The majority of Medicare patients who were treated (96.6%, n = 64,651) had a score of 9 or less, which correlated with a mortality <5%. Only 3.4% of patients had a mortality >or=5% and 0.8% of patients (n = 509) had a score of 13 or higher, which correlated with a mortality >10%.

CONCLUSION

We conclude that there is a high-risk cohort of patients that should not be treated with EVAR because of prohibitively high mortality; however, this cohort is small. Our scoring system, which is based on patient and institutional factors, provides criteria that can be easily used by clinicians to quantify perioperative risk for EVAR candidates.

Multislice CT angiography of fenestrated endovascular stent grafting for treating abdominal aortic aneurysms: a pictorial review of the 2D/3D visualizations

Fenestrated endovascular repair of an abdominal aortic aneurysm has been developed to treat patients with a short or complicated aneurysm neck. Fenestration involves creating an opening in the graft fabric to accommodate the orifice of the vessel that is targeted for preservation. Fixation of the fenestration to the renal arteries and the other visceral arteries can be done by implanting bare or covered stents across the graft-artery ostia interfaces so that a portion of the stent protrudes into the aortic lumen. Accurate alignment of the targeted vessels in a longitudinal aspect is hard to achieve during stent deployment because rotation of the stent graft may take place during delivery from the sheath. Understanding the 3D relationship of the aortic branches and the fenestrated vessel stents following fenestration will aid endovascular specialists to evaluate how the stent graft is situated within the aorta after placement of fenestrations. The aim of this article is to provide the 2D and 3D imaging appearances of the fenestrated endovascular grafts that were implanted in a group of patients with abdominal aortic aneurysms, based on the multislice CT angiography. The potential applications of each visualization technique were explored and compared with the 2D axial images.

Helical CT angiography of fenestrated stent grafting of abdominal aortic aneurysms

Fenestrated stent grafts have been developed to treat patients with abdominal aortic aneurysms (AAA) associated with complicated aneurysm necks, such as short necks, severe angulated or poor quality necks (presence of calcification or thrombus). The technique is performed by creating an opening in the graft material so that the stent graft can be placed above the renal and other visceral branches without compromising blood perfusion to these vessels. In most situations, a supporting stent is inserted into the fenestrated vessel to provide fixation of the fenestrated vessel against stent grafts, as well as to preserve patency of the vessel. Helical CT angiography (CTA) is the preferred imaging modality in both pre-operative planning and post-procedural follow-up of fenestrated repair of AAA. The main concerns of fenestrated stent grafting lie in the following two aspects: patency of the fenestrated vessels and position of the fenestrated stents in relation to the artery branches. In this article, the author presents the clinical applications of 2D and 3D visualizations in the follow-up of patients with AAA treated with fenestrated stent grafts, with the aim of providing useful information to readers and increasing their knowledge of an increasingly used technique, fenestrated stent grafting in the treatment of AAA.

Endovascular treatment of abdominal aortic aneurysms in high-surgical-risk patients

Background: Following the publication of a prospective randomized trial (Endovascular Aneurysm Repair Trial 2 - EVAR2) that questioned the benefits of endovascular repair of abdominal aortic aneurysms (AAA) in high-surgical-risk patients, we decided to analyze our initial and long-term results with endovascular AAA repair in this patient population. Objective: To evaluate the operative mortality, long-term survival, frequency of secondary operations, outcome of the aneurysm sac, primary and secondary patency rates, and rupture rate after aortic stent-graft placement in high-surgical-risk patients. Methods: From April 2002 to February 2008, 40 high-surgical and anesthetic risk patients with an AAA managed by a bifurcated aortic endograft were entered in a prospective registry. Data concerning diagnosis, operative risk, treatment and follow-up were analyzed in all patients Results: Twenty-four Excluder® and 16 Zenith® stent-grafts were successfully implanted. Thirty patients (75%) were classed ASA III and 10 (25%) were ASA IV. Mean aneurysm diameter was 64 mm. Operative mortality was 2.5%. Two patients required reintervention during the mean follow-up of 28.5 months. Survival rate at 3 years was 95%. There were four endoleaks, one case of endotension, and one endograft limb occlusion. Primary and secondary patency rates at 3 years were 97.5 and 100%, respectively. There were no ruptures. Conclusions: Initial and long-term results with endovascular treatment of AAA in high-surgical-risk patients were satisfactory, and appear to justify such approach for this patient population.

Impact of the introduction of endovascular aneurysm repair in high-risk patients on our practice of elective treatment of infrarenal abdominal aortic aneurysms

The aim of this work was to evaluate, in terms of activity and immediate postoperative results, the modifications of our elective surgical treatment of infrarenal abdominal aortic aneurysms (AAAs) resulting from the use of stent grafts to treat AAAs, following the recommendations issued by the French Health Products Safety Agency (AFSSAPS) in December 2003. This monocentric and retrospective study used the clinical data of patients operated on for asymptomatic AAA between January 2001 and December 2006. Endovascular treatment of AAAs with aortic stent grafts was introduced in our current practice in January 2004, following the recommendations of the AFSSAPS (high-risk patients for open surgery presenting with an AAA > or =50 mm). Group I was composed of patients operated on between January 2001 and December 2003 according to the standard open technique. Group II was composed of patients operated on between January 2004 and December 2006 with either standard open surgery or endovascular surgery. The main criteria of evaluation were the number of operated patients, their American Society of Anesthesiology (ASA) score of surgical risk, and the intrahospital morbidity and mortality. The number of treated patients significantly increased between these two periods (group I n = 49, group II n = 88, with 38 endovascular treatments; p < 0.001), without any changes in average age (70 vs. 72 years), percentage of men (93.7% vs. 95.5%), and mean AAA size (57.8 vs. 56 mm) between the two groups. ASA scores were significantly higher in group II (ASA III and IV, group I = 20.4% vs. group II = 55.7%; p < 0.0001), whereas the intrahospital mortality rate (4.1% vs. 3.4%) and the rate of major postoperative complications (16.3% vs. 11%) have remained stable. In group II, the median duration of hospitalization was significantly reduced (12 vs. 9 days, p < 0.001). In conclusion, in our center, following the AFSSAPS recommendations, the introduction of endovascular treatment has enabled us to electively treat a greater number of AAA patients with higher surgical risk, without aggravating the immediate postoperative results.

CT virtual intravascular endoscopy in the visualization of fenestrated stent-grafts

PURPOSE

To report the diagnostic value of computed tomographic (CT) virtual intravascular endoscopy (VIE) in the assessment of patients with abdominal aortic aneurysm (AAA) treated with fenestrated endovascular grafts.

METHODS

Eight patients (7 men; mean age 76 years, range 70-82) with AAAs unsuitable for open surgery or conventional endovascular repair had fenestrated endovascular grafts implanted. Both pre- and post-fenestration multislice CT data were used to generate VIE images of the visceral artery ostia and the side branch fenestrated stents. CT VIE images were compared with conventional 2-dimensional (2D) axial CT and multiplanar reformatted (MPR) images for the ability to visualize the intraluminal appearance of stents, as well as to measure the length of stents that protruded into the aortic lumen.

RESULTS

Various fenestrations were deployed in 27 aortic branches. Scalloped and large fenestrations were implanted in 6 side branch ostia, respectively, and small fenestrations in 15 renal artery ostia. Fewer than half of the stents (37%) were found to be circular on VIE images, while the remaining stents were flared to varying extents at the inferior portion. The majority (96%) of stents protruded into the lumen up to 7.0 mm. Although the configuration of the side branch ostia changed to a variable extent, no significant difference was apparent between the diameters of branch ostia before and after fenestration (p>0.05).

CONCLUSION

Our preliminary study shows that VIE proved superior to conventional 2D or MPR images in visualizing the final configuration of the fenestrated vessels and was comparable to the other techniques in measuring stent protrusion into the aortic lumen. VIE could be a valuable technique to identify any suspected abnormalities associated with fenestrated endovascular grafts by demonstrating the final intraluminal configuration of the stents in the fenestrated vessels.

Are Statins an Option in the Management of Abdominal Aortic Aneurysms?

Medline was searched for studies investigating the perioperative and long-term results that derive from statin use in patients with abdominal aortic aneurysm and the clinical and experimental evidence dealing with aneurysm expansion. Data suggest that statins improve the perioperative and long-term outcomes of aneurysm operations and may also reduce expansion rates. International guidelines recommend the use of statins in these patients because abdominal aortic aneurysms are considered as a coronary heart disease equivalent. These guidelines do not appear to have been widely implemented. Preliminary results suggest that statins might play a role in the management of abdominal aortic aneurysms. Verification of these results in large-scale trials may hold implications for a more comprehensive approach of patients with abdominal aortic aneurysms as well as population-wide aneurysm screening programs. Irrespective of the role of statins on aneurysm expansion rates, it is important to ensure that all abdominal aortic aneurysm patients receive statin therapy to improve perioperative and long-term morbidity and mortality.

Minimally invasive retrieval of a dislodged Wallstent endoprosthesis after an endovascular abdominal aortic aneurysm repair

Endovascular abdominal aortic aneurysm repair (EVAR) is being performed more frequently in patients with concomitant iliac artery occlusive disease. We report a case of a 70-year-old male status post angioplasty and stenting of bilateral iliac arteries for occlusive disease who subsequently underwent EVAR for a rapidly expanding abdominal aortic aneurysm (AAA). One month after the placement of the endograft, it was discovered that the previously placed Wallstent had been dislodged during the endovascular abdominal aortic aneurysm repair. Minimally invasive retrieval using an Amplatz Goose Neck Snare was successful in recovering the stent. This case underscores the danger of performing EVAR in the setting of prior iliac artery stenting and the potential complications that may ensue.

Effect of suprarenal fixation of aortic stent-grafts on the renal artery ostia: assessment of morphological changes by virtual intravascular endoscopy

PURPOSE

To investigate the morphological effects of suprarenal fixation of aortic stent-grafts on the renal artery ostia (RaO) by analysis of suprarenal stent wire distribution and vascular calcification across the RaO using virtual intravascular endoscopy (VIE).

METHODS

Fourteen consecutive patients (11 men; mean age 75 years) from a single institution were studied following endovascular aortic aneurysm repair (EVAR) using the Zenith endograft system from September 1999 to March 2002. Imaging assessment included computed tomographic (CT) measurement of renal artery intraluminal ostial diameter and quantification and analysis of uncovered stent struts across the RaO and radiological determination of RaO calcification. Morphological changes following EVAR at 3 time points (before and within 1 week after stent-grafting, and at the most recent follow-up) were compared for each patient to determine whether suprarenal stent struts or RaO calcification affected intraluminal ostial diameter. Renal function was assessed by temporal measurements of serum creatinine concentration and creatinine clearance.

RESULTS

The renal ostium was distorted to variable degrees in all cases at a mean follow-up of 41+/-6.6 months. An increase in ostial diameter was identified in most patients if the right RaO was calcified when comparing the 1-week postoperative and most recent follow-up CT images (p<0.05). There was no direct relationship between the number of stent struts crossing the RaO and the morphological/dimensional changes (p>0.05). Renal function was not significantly affected.

CONCLUSION

Patients undergoing suprarenal fixation of aortic stent-grafts experienced morphological changes of the RaO to a variable extent at midterm follow-up. Although the presence of stent struts did not significantly affect dimensional changes, we observed that calcification at the renal artery ostium may influence the development of atherosclerotic effects as a direct relationship between the calcification and ostial diameter. Future studies utilizing VIE to determine the long-term safety of this technique in these particular patients requires investigation.