How Many Patients with Infrarenal Aneurysms are Candidates for Endovascular Repair? The Northern California Experience

Endovascular repair of an abdominal aortic aneurysm with external iliac artery occlusion using VBX as the contralateral leg via axillary delivery: A case report

RATIONALE

A hostile iliac access route is an important consideration when enforcing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAA). Herein, we report a case of AAA with unilateral external iliac artery occlusion, for which bifurcated EVAR was successfully performed using a single femoral and brachial artery access.

PATIENT CONCERNS

A 76-year-old man who had undergone surgery for lung cancer 4.5 years prior was diagnosed AAA by computed tomography (CT).

DIAGNOSIS

Two and a half years before presentation, CT revealed an infrarenal 48 mm AAA, which had enlarged to 57 mm by 2 months preoperatively. CT identified occlusion from the right external iliac artery to the right common femoral artery, with no observed ischemic symptoms in his right leg. The right external iliac artery, occluded and atrophied, had a 1 to 2 mm diameter.

INTERVENTION

Surgery was commenced with the selection of a Zenith endovascular graft (Cook Medical) with an extended body length. Two Gore Viabahn VBX balloon expandable endoprosthesis (VBX; W.L. Gore & Associate) were delivered from the right axilla as the contralateral leg.

OUTCOMES

CT scan on the 2nd day after surgery revealed no endoleaks.

LESSONS

While the long-term results remain uncertain, this method may serve as an option for EVAR in patients with unilateral external iliac artery occlusion.

Impact of iliac access in elective and non-elective endovascular repair of abdominal aortic aneurysm

Endovascular aortic repair (EVAR) is nowadays the establishment treatment for patients with abdominal aortic aneurysm (AAA) both in elective and urgent setting. Despite the large applicability and satisfactory results, the presence of hostile iliac anatomy affects both technical and clinical success. This narrative review aimed to report the impact of iliac access and related adjunctive procedures in patients undergoing EVAR in elective and non-elective setting. Hostile iliac access can be defined in presence of narrowed, tortuous, calcified, or occluded iliac arteries. These iliac characteristics can be graded by the anatomic severity grade score to quantitatively assess anatomic complexity before undergoing treatment. Literature shows that iliac hostility has an impact on device navigability, insertion and perioperative and postoperative results. Overall, it has been correlated to higher rate of access issues, representing up to 30% of the first published EVAR experience. Recent innovations with low-profile endografts have reduced large-bore sheaths related issues. However, iliac-related complications still represent an issue, and several adjunctive endovascular and surgical strategies are nowadays available to overcome these complications during EVAR. In urgent settings iliac hostility can significantly impact on particular time sensitive procedures. Moreover, in case of severe hostility patients might be written off for EVAR repair might be inapplicable, exposing to higher mortality/morbidity risk in this urgent/emergent setting. In conclusion, an accurate anatomical evaluation of iliac arteries during preoperative planning, materials availability, and skilled preparation to face iliac-related issues are crucial to address these challenges.

Female Sex Is Associated With Reintervention and Mortality Following Elective Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

While sex differences in endovascular abdominal aortic aneurysm repair (EVAR) outcomes are increasingly reported, but contributing factors remain without consensus. We investigated disparities in sex-specific outcomes following elective EVAR at our institution and evaluated factors that may predispose females to increased morbidity and mortality.

METHODS

A retrospective chart review of all patients undergoing elective EVAR from 2011 to 2020 at a suburban tertiary care center was performed. The primary outcomes were five-year survival and freedom from reintervention. Fisher's exact test, t-tests, and Kaplan-Meier analysis using the rank-log test investigated associations between sex and outcomes. A multivariable Cox proportional hazard model controlling for age and common comorbidities evaluated the effect of sex on survival and freedom from reintervention.

RESULTS

Two hundred and seventy-three patients underwent elective EVAR during the study period, including 68 (25%) females and 205 (75%) males. Females were older on average than males (76 years vs. 73 years, p= <0.01) and were more likely to have chronic obstructive pulmonary disease (COPD; 38% versus 23%, p=0.01), require home oxygen therapy (9% versus 2%, p=0.04) or dialysis preoperatively (4% versus 0%, p=0.02). Distribution of other common vascular comorbidities was similar between the sexes. Thirty-day readmission was greater in females than males (18% versus 8%, p=0.02). Females had significantly lower survival at five years (48% ± 7.9% versus 65% ± 4.3%, p<0.01) and significantly lower one-year (89% ± 4.1% for females vs. 94% ± 1.7% for males, p=0.01) and five-year freedom from reintervention (69% ± 8.9% versus 84% ± 3.3%, p=0.02). On multivariable analysis, female sex (hazard ratio [HR]: 1.8, 95% confidence interval [CI]: 1.1-2.9), congestive heart failure (HR: 2.2, 95% CI: 1.2-3.9) and age (HR: 1.1, 95% CI: 1.0-1.1) were associated with 5-year mortality. Female sex remained as the only variable with a statistically significant association with five-year reintervention (HR: 2.4, 95% CI: 1.1-4.9).

CONCLUSIONS

Female sex was associated with decreased five-year survival and increased one and five-year reintervention following elective EVAR. Data from our institution suggests factors beyond patient age and baseline health risk likely contribute to greater surgical morbidity and mortality for females following elective EVAR.

Treatment of a Delayed Type IIIb Endoleak 20 Years Post EVAR With Inverted Contralateral Limb Custom-Made Device: A Case Report

PURPOSE

Type III endoleak can be difficult to distinguish from Type I endoleak. Depending on the stent graft anatomy, the use of standard bifurcated endografts may not be technically feasible, and patients may have to be subject to an aorto-uni-iliac repair with femoral-femoral bypass or open surgery.

CASE REPORT

We report a case of an 86-year-old male who had a Type IIIb endoleak 20 years post EVAR which was characterized on angiography to be from a hole close to the bifurcation limb origin. The initial Talent (Medtronic, Santa Rosa, California) device had a 50 mm main body common trunk, which was not amenable to treatment with standard devices. He was successfully treated with a custom-made device with an inverted contralateral limb.

CONCLUSIONS

Our case highlights the need for lifelong surveillance post EVAR as endoleak may present decades post initial EVAR. It also demonstrates that many Type III endoleak which were otherwise deemed unsuitable for treatment with standard devices may potentially be treatable with custom-made device (CMD). This solution preserves a percutaneous option in a now older person which avoids surgical bypass. Further studies are required to establish the durability of this treatment and survey for recurrence.

Direct puncture of an occluded common femoral artery as a new approach for endovascular aortic aneurysm repair

Background

Abdominal aortic aneurysms (AAA) which present with a hostile access are not uncommon. When an arterial occlusion continuously involves from the iliac to the femoropopliteal artery, endovascular aneurysm repair (EVAR) can become complex, necessitating an adjunctive surgical procedure. The present report outlines a successful EVAR which was conducted without any adjunctive surgical procedure for an AAA complicated by extensive access vessel occlusion.

Case presentation

The patient, an 82-year-old male, had a fusiform 50 mm infrarenal AAA. He had a history of above knee amputation of the right leg due to a gangrene from Buerger’s Disease. Despite the continuous occlusions of the right external iliac artery (EIA), common femoral artery (CFA), and superficial femoral and profunda femoris artery, limb ischemia was not observed in his right leg. Since revascularization of the occluded right iliac and femoral arteries was deemed to be too complex technically and no ischemic symptoms were observed, EVAR was performed using the occluded access only for the delivery of the stent graft without restoring the flow. Firstly, the occluded right CFA was punctured under ultrasound guidance. Next, a 0.014 in. guidewire and a microcatheter were successfully navigated to the subintimal space of the right common iliac artery (CIA), these were then exchanged with a reentry device. The reentry device allowed the advancement of a guidewire into the true lumen of the right CIA. Then, a 12Fr sheath for delivery of a contralateral limb was advanced via the occluded right access to aorta, and a 16 Fr sheath for delivery of a main body graft was advanced via a patent left iliac artery. A standard EVAR procedure was subsequently performed.

Conclusions

EVAR was successfully performed for an AAA complicated with an arterial occlusion from the EIA to the SFA using direct puncture of the occluded CFA. This technique could be an effective measure for cases with a hostile access involving the CFA.

Predictors of Aneurysm Sac Shrinkage Utilizing a Global Registry

BACKGROUND

Aneurysm sac remodeling is a complex multifactorial process with unknown factors influencing sac regression after endovascular aortic aneurysm repair (EVAR). We sought to identify factors associated with this process by analyzing data obtained from patients treated with the GORE EXCLUDER endovascular aneurysm repair (EVAR) endoprosthesis from December 2010 to October 2016 enrolled in the Global Registry for Endovascular Aortic Treatment (GREAT).

METHODS

All patients enrolled in GREAT with three years CT angiography (CTA) follow-up in each of the three successive years after EVAR were included. The percentage of sac size reduction toward device diameter was calculated and used as a surrogate for sac regression with the formula used being: sac size reduction = ((AAA baseline diameter - AAA diameter at follow-up)/(AAA baseline diameter - device diameter))∗100. The cohort was divided into two groups in accordance with the percentage of aneurysm sac reduction at three years; one with the top quartile of patients and the other with the lowest three quartiles. Demographic and procedural variables were analyzed using univariate and regression modeling to determine factors predictive of sac regression.

RESULTS

There were 3265 subjects enrolled with follow-up as of May 2018 of which 526 (16.2%) had three years of CTA surveillance. Overall aneurysm sac size decreased from a mean of 58.0 mm (Std Dev: 10.4, range: 34.2, 100.0) to a mean of 49.3 mm (Std Dev: 14.1, range: 0, 140) for a percentage reduction toward device diameter of a mean 28.2% (Std Dev: 39.0, range: -103.7, 183.9). On multivariate logistic regression model; two factors proved to be statistically significant contributors to a larger percentage reduction in aneurysm sac: a conical neck (odds ratio [OR] = 1.64, P-value = 0.023) and a larger proximal device diameter (OR = 1.09, P-value = 0.023). On the other hand, two factors were negative predictors of sac shrinkage, namely: old age (OR = 0.96, P-value = 0.002) and larger baseline aneurysm sac diameter (OR = 0.98, P-value = 0.028).

CONCLUSIONS

Aneurysms with conical necks and larger proximal device neck diameters have an increased percentage change in sac size over time after EVAR. Older age and larger initial diameters of aneurysms were negatively associated with percentage change in sac size as well as sac regression. Further study is needed to determine the clinical utility of these observations and applicability across multiple endoprosthesis platforms.

Balloon-oriented puncture for creating an access for endovascular aortic aneurysm repair in a case of iliac and femoral artery occlusion

Background

Abdominal aortic aneurysms (AAA) with iliac artery occlusive diseases are not uncommon. When an occlusion extends from iliac artery to common femoral artery (CFA), adjunctive procedures such as endareterectomy of CFA and angioplasty of iliac artery are performed prior to endovascular aneurysm repair (EVAR). Alternatively, aorto-uni-iliac stentgrafting with femoro-femoro bypass surgery could be performed. If run off vessels such as superficial femoral artery (SFA) and profunda femoris artery (PFA) are both occluded in addition to the CFA, surgical procedures may become extremely complex, with much longer procedure time. We present an unusual case of AAA with arterial occlusion ranging from external iliac artery (EIA) to superficial and profunda femoris arteries, which was fully managed with endovascular means.

Case presentation

The patient was a 76 year old male who was found incidentally to have a fusiform infrarenal AAA, the size of which was 55 mm in maximal transverse diameter. Despite the occlusions of left EIA, CFA and proximal parts of SFA and PFA, he did not have ischemic symptoms in his left leg due to the development of abundant collateral networks from left internal iliac artery. The patient had a past history of endarterectomy of left CFA. Since a repeated endarterectomy or interposition grafting of the CFA were deemed extremely difficult, without any patent runoff vessel, EVAR was performed using the occluded vessel simply as a conduit for the delivery of the endograft, without revascularizing the vessel. An angioplasty balloon was delivered from right CFA to the occluded left CFA through a subintimal space. A percutaneous puncture of the expanded balloon was done at the occluded left CFA under fluoroscopy, inserting the guidewire into the punctured balloon, finally establishing the through and through wire. EVAR was successfully performed using AFX unibody stentgraft without any complication.

Conclusion

AAA with access vessel occlusions from EIA to SFA was successfully treated with EVAR with the aid of the balloon oriented percutaneous puncture technique. Having the technique as an armamentarium can broaden the application of EVAR for AAA with the complicated access.

LUCY results show females have equivalent outcomes to males following endovascular abdominal aortic aneurysm repair despite more complex aortic morphology

OBJECTIVE

Females remain underrepresented in studies of endovascular aneurysm repair (EVAR) owing to anatomic ineligibility for EVAR devices. The aim of the LUCY study is to explore the comparative safety and effectiveness of EVAR using a low-profile stent graft (Ovation; Endologix, Inc, Irvine, Calif) in females as well as males.

METHODS

The LUCY registry was a prospective, nonrandomized, multicenter study where patient enrollment was stratified by sex in a two-to-one ratio (male-to-female). Main outcomes were procedural data, 30-day major adverse events, device-related adverse events confirmed with contrast-enhanced computed tomography scans, secondary interventions, and hospital readmissions. Adverse events were adjudicated by a clinical events committee. Patients were followed at their 1-month and 1-year follow-up visits.

RESULTS

A total of 225 patients (76 females, 149 males) were enrolled at 39 U.S. centers. No statistically significant sex differences were observed in demographics or medical history. Females presented with smaller access vessels (6.2 vs 7.7 mm; P < .001), statistically smaller neck diameter (22 mm vs 23 mm; P = .001), similar neck angulation (11% vs 9% angulation >45°; P = .81), and smaller maximum abdominal aortic aneurysm (AAA) diameter (50 mm vs 53 mm; P = .01), however, these factors do not seem to be clinically significant. Technical success was 99%, and the median hospital stay was 1 day. The incidence of MAE through 30 days was 1.3% in females and 2.0% in males. There were no differences between sexes observed among the 30-day perioperative outcomes. The 30-day secondary intervention rate was 0.4%. The all-cause readmission rate through 30 days was 5.3% in females and 6.7% in males. There were no reports of limb occlusion or deaths within the first 30 days. At 1 year, there were no deaths in the female arm but nine deaths (6.0%) were observed in males, two of which were AAA related (1.3%). Through 1 year, there were eight type IA endoleaks (one female, seven males; P = .27) and three cases with limb occlusion (one female, two males). There were no reports of migration, AAA rupture, or surgical conversion through the end of follow-up.

CONCLUSIONS

Despite more complex aortic morphology in females than males, EVAR with a low-profile stent graft was associated with comparable procedural and perioperative outcomes through 1 year between the sexes.

Endovascular repair of an abdominal aortic aneurysm using bifurcated stent-graft in a patient with bilateral external iliac artery occlusion

Abdominal aortic aneurysm (AAA) in association with external iliac artery (EIA) occlusion is a rare entity which may limit endovascular aortic aneurysm repair (EVAR) feasibility. We describe the case of an 84-year-old man affected by a 64mm infrarenal inflammatory abdominal aortic aneurysm with complete bilateral occlusion of EIA and patency of both common and internal iliac arteries. The common femoral arteries (CFA) were patent, and the patient was asymptomatic for lower limb claudication. The treatment was performed by EVAR using a bifurcated stent-graft after the recanalization of the left EIA, achieving technical success.

Using bifurcated endoprosthesis after iliac artery recanalization for concomitant abdominal aortic aneurysm and chronic total occlusions of access routes

OBJECTIVE

Concurrent abdominal aortic aneurysm (AAA) and unilateral iliac occlusion is a challenge in the implantation of bifurcated stent grafts (BFGs). The endovascular approach is less invasive than open surgery; the aortouni-iliac (AUI) graft with crossover femorofemoral bypass (CFFB) has many problems associated with extra-anatomic reconstruction. We attempted endovascular aneurysm repair (EVAR) using BFGs in such cases and evaluated the outcomes.

METHODS

This was a retrospective study. Between October 2012 and December 2017, there were 649 patients who underwent surgery for AAA, of whom 32 patients underwent open reconstruction and 617 patients underwent endovascular aneurysm repair; 15 patients with unilateral occluded iliac arteries and AAA were included. The analysis included patients with unilateral iliac chronic total occlusion (CTO). The intraoperative, postoperative, and follow-up variables were reviewed.

RESULTS

The occluded lesions were the common iliac artery in 5 patients, the common iliac artery-external iliac artery (EIA) in 2 patients, the EIA in 7 patients, and the EIA-common femoral artery in 1 patient. The mean occlusive length was 89.7 ± 43.6 mm, and the mean AAA size was 54.6 ± 5.6 mm. Technical success was achieved in 13 patients (87%). All patients underwent recanalization through the true lumen and stent placement. The only procedure-related complication was distal embolism, which was treated with intraoperative thrombectomy. Recanalization of CTO lesions was not possible in two patients (13%), who underwent AUI graft placement with CFFB. The 30-day mortality and morbidity rates were 0%. The mean follow-up periods were 12 and 32 months for patients who underwent BFG placement and AUI graft placement with CFFB, respectively. During follow-up, the primary patency rate of successfully recanalized arteries was 100%. Aneurysm size decreased in four patients who underwent BFG placement; no change was seen in the other 11 patients. Freedom from aneurysm-related events was 100%; no patient needed secondary interventions. All patients with claudication pain preoperatively reported improvement in their symptoms during follow-up. In addition, the ankle-brachial index improved significantly from 0.51 ± 0.25 preoperatively to 0.88 ± 0.20 postoperatively (P < .001) in patients who underwent BFG placement.

CONCLUSIONS

Recanalization of unilateral iliac CTO lesions and placement of BFG in cases with concomitant aneurysmal disease and unilateral iliac occlusive disease demonstrated a significant primary patency rate with improvements in claudication and ankle-brachial index.

Complications and Reinterventions After Fenestrated and Branched EVAR in Patients with Paravisceral and Thoracoabdominal Aneurysms

The application of endovascular strategies to treat aneurysms involving the abdominal and thoracoabdominal aorta has evolved significantly since the inception of endovascular aneurysm repair. Advances in endograft technology and operator experience have enabled the management of a wider spectrum of challenging aortic anatomy. Fenestrated endovascular and branched endovascular aneurysm repair represent two technical innovations, which have expanded endovascular treatment options to include patients with paravisceral and thoracoabdominal aortic aneurysms. Although similar in many ways to standard aortic endografts, fenestrated and branched endografts have specific short- and long-term complications due to their unique modular endograft design and their sophisticated deployment mechanisms. This article aims to examine the commonly encountered complications with these devices and the endovascular reintervention strategies.

Femorofemoral Crossover Bypass Graft Has Excellent Patency When Performed with EVAR for AAA with UIOD

OBJECTIVES

To compare the durability of the crossover femorofemoral bypass graft (CFFBG) in combination with aorto-uni-iliac stent graft (AUIS) for abdominal aortic aneurysm with the durability of CFFBG used in the treatment of unilateral iliac occlusive disease (UIOD).

METHODS

We analyzed the clinical records of 69 patients who underwent CFFBG from 1992 until 2010. Group I consisted of 34 patients who received CFFBGs in combination with AUIS. Group II consisted of 35 patients treated with CFFBG for UIOD. The mean period of follow up was 2.7 years. Outcomes analyzed included primary graft patency, secondary graft patency, and postoperative morbidity and mortality.

RESULTS

There was one death in each group. Wound infection complicated 11.4% of CFFBGs performed as a sole procedure for UIOD and 5.8% of cases in combination with AUIS (P = 0.673). Primary graft patency was 96.5% and 96.5% at 2 and 5 years in group I, compared with 76.6% and 53.7% in group II (P = 0.046, 0.009). Secondary graft patency at 5 years was 100% and 92.9% for groups I and II, respectively. No variables independently influenced primary graft patency. Patients in group I experienced complications that could be linked to the bypass graft in 20.5% of cases, after long-term follow-up.

CONCLUSIONS

The CFFBG possesses superior long-term durability and patency when implemented in combination with aorto-uni-iliac stent grafts and does not seem to compromise the endpoint success of endovascular treatment.

Endovascular Treatment of Abdominal Aortic Aneurysm with Complete Iliac Occlusion: Case Series and Literature Review

In patients with abdominal aortic aneurysms (AAA) and complete iliac occlusion, endovascular aortic aneurysm repair (EVAR) using a bifurcated stent graft has clear advantages over aortouniiliac stent grafts. Bifurcated stent grafts had improved hemodynamic flow and increased primary and secondary patency rates compared with aortouniiliac stent grafts. The use of aortouniiliac stent grafts with femorofemoral crossover bypass is associated with complications including infection of the prosthesis, steal phenomenon, and the associated difficulties for further endovascular access at the site of the femoral anastomosis. Recanalization of occluded iliac arteries at the time of EVAR avoids the complications mentioned above. We report three cases of patients with AAA and iliac occlusion who were successfully treated with iliac recanalization at the time of EVAR.

Iliac Stent Migration during Thoracic Endovascular Aortic Aneurysm Repair Resulting in Functional Coarctation

Iliac arterial disease, unfavorable anatomy, and prior stenting all pose challenges to access in endovascular abdominal aortic repair (EVAR) and thoracic aortic repair (TEVAR). Iliac access injury during T/EVAR may lead to rupture, dissection, thrombosis, or distal ischemia. Some have advocated iliac stent prior to T/EVAR in patients with suboptimal iliac access. The rate of complication and iliac stent migration during subsequent T/EVAR is undocumented. This case report describes a unique instance of self-expanding iliac stent migration during TEVAR which pinched the thoracic aortic endograft causing functional aortic coarctation.

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).

Anaphylactic Reaction during Implantation of Ovation Abdominal Stent Graft in Patients with Abdominal Aortic Aneurysm

The Ovation Abdominal Stent Graft System is a trimodular endoprosthesis planned to overcome the limitations of currently available stent grafts, allowing complex iliac and femoral access and providing a proximal seal in challenge infrarenal neck morphology. The proximal sealing is achieved by means of a network of inflatable rings filled with low-viscosity radiopaque polyethylene glycol-based polymer during stent-graft deployment. The leakage of polymer outside the channel to fill the rings into the vascular system may induce an hypersensitivity reaction and anaphylactic shock. We report a case of anaphylactic reaction during Ovation Abdominal Stent Graft System implantation. The endovascular procedure was successfully concluded.

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.

In Vivo Antegrade Fenestration of Abdominal Aortic Stent-Grafts

Purpose:

To examine in a canine model the feasibility of antegrade fenestration of abdominal aortic stent-grafts to preserve the patency of the renal arteries.

Methods:

Two large dogs underwent antegrade fenestration of stent-grafts in the perirenal aorta. Before fenestration, bare stents were inserted in both renal arteries as fluoroscopic landmarks. A 12-mm iliac extension served as the canine aortic endograft. The first procedure was done under ultrasound and fluoroscopic guidance, using an intravascular ultrasound (IVUS) probe inserted in the vena cava and a Pioneer IVUS catheter. The second was performed exclusively under fluoroscopic guidance with a Brockenbrough needle. Angiograms and duplex ultrasound were planned for 1 month, after which the dogs would be sacrificed for autopsy. The explanted endograft was subjected to biomaterials analysis, with a focus on fabric tear.

Results:

Perforation of the aortic graft and catheterization of the renal arteries with a floppy guidewire were possible in both animals. In dog 1, aortic graft dilation and subsequent fenestration were not possible, and the experiment was terminated. However, the procedure was successful in both renal arteries of dog 2. At 1-month follow-up in this dog, both renal arteries were patent. Stent fractures were observed bilaterally. There was no extension of the damage to the fabric beyond the area of fenestration.

Conclusion:

In vivo antegrade fenestration of aortic endografts is technically feasible. However, improvements in technique, instrumentation, and materials are required to make it a reliable and reproducible way of allowing stent-graft vascularization of aortic side branches.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

The Acute Abdominal Aorta

Acute disorders of the abdominal aorta are potentially lethal conditions that require prompt evaluation and treatment. Computed tomography (CT) is the primary imaging method for evaluating these conditions because of its availability and speed. Volumetric CT acquisition with multiplanar reconstruction and three-dimensional analysis is now the standard technique for evaluating the aorta. MR imaging may be useful for select applications in stable patients in whom rupture has been excluded. Imaging is indispensable for diagnosis and treatment planning, because management has shifted toward endoluminal repair. Acute abdominal aortic conditions most commonly are complications of aneurysms and atherosclerosis.

Aorto-Uni-Iliac Stent Grafts with and without Crossover Femorofemoral Bypass for Treatment of Abdominal Aortic Aneurysms: A Parallel Observational Comparative Study

We investigated the safety and efficacy of primary aorto-uni-iliac (AUI) endovascular aortic repair (EVAR) without fem-fem crossover in patients with abdominal aortic aneurysm (AAA) and concomitant aortoiliac occlusive disease. 537 EVARs were implemented between 2002 and 2015 in University Hospital Galway, a tertiary referral center for aortic surgery and EVAR. We executed a parallel observational comparative study between 34 patients with AUI with femorofemoral crossover (group A) and six patients treated with AUI but without the crossover (group B). Group B patients presented with infrarenal AAAs with associated total occlusion of one iliac axis and high comorbidities. Technical success was 97% (n = 33) in group A and 85% (n = 5) in group B (P = 0.31). Primary and assisted clinical success at 24 months were 88% (n = 30) and 12% (n = 4), respectively, in group A, and 85% (n = 5) and 15% (n = 1), respectively, in group B (P = 0.125). Reintervention rate was 10% (n = 3) in group A and 0% in group B (P = 0.084). No incidence of postoperative critical lower limb ischemia or amputations occurred in the follow-up period. AUI without crossover bypass is a viable option in selected cases.

Open and endovascular repair of juxtarenal abdominal aortic aneurysms: a systematic review

This systematic review focuses on the 30-day mortality associated with open surgery and fenestrated endografts for short-necked (<15 mm) juxtarenal abdominal aortic aneurysms. A search for studies published in English and indexed in the PubMed and Medline electronic databases from 2002 to 2012 was performed, using "juxtarenal abdominal aortic aneurysm" and "treatment" as the main keywords. Among the 110 potentially relevant studies that were initially identified, eight were in accordance with the inclusion criteria in the analysis. Similar outcomes for open and endovascular repair were observed for 30-day mortality. No differences were observed regarding the secondary outcomes (duration of surgery, hospital stay, postoperative renal dysfunction and late mortality), except that the late mortality rate was significantly higher for the patients treated with open repair after a median follow-up of 24 months. Fenestrated endografting is a viable alternative to conventional surgery in juxtarenal abdominal aortic aneurysms with a proximal neck <15 mm.

Quantification of dilated infrarenal aorta by 64 multidetector computed tomographic evaluation in preventing EVAR complications in patients of different races

AIM

The hypothesis of this multicentric study is performing a specific typification in the selection of grafts for the endoluminal treatment of an aneurysmally altered distal aorta based on mathematical information and the correlation of a number of morphological parameters diagnosed by 64-multidetector computed tomographic (CT) aortography.

MATERIALS AND METHODS

The study is multicentric and encompassed 30 Asian and 30 European patients. Examinations were performed on the same type of 64- multidetector CT equipment and under same conditions of examination technique and postprocessing. Several statistical methods were applied to analyze the results.

RESULTS

Statistically significant differences were found between Asian and European patients in the morphology of the central part of the aneurysm at the level of the abdominal aorta and the width and length of the iliac arteries. The principal cause of the most frequent complication observed was defined by a CT aortographic study.

CONCLUSIONS

Computed tomographic aortographic quantification of significant parameters makes it possible to plan the exact dimensions of grafts in each individual case. Computed tomographic examinations make possible very exact measurements and positioning of the graft of the novel design proposed by the authors and expected to substantially reduce the incidence of complications.

Resident and fellow experiences after the introduction of endovascular aneurysm repair for abdominal aortic aneurysm

OBJECTIVES

This study assessed trends in open and endovascular repair (EVAR) of intact and ruptured abdominal aortic aneurysm (AAA) in the Medicare population and evaluated recent trends in AAA repair at vascular fellowship training programs.

METHODS

We identified all Medicare beneficiaries with a diagnosis of AAA who underwent repair or had a primary diagnosis of rupture (1995-2008). Cohorts were compared by type of repair (open vs EVAR) and presentation (intact vs ruptured AAA). Demographics of age, sex, and race were evaluated. We used unique hospital identifier codes to compare trends and 30-day mortality between hospitals that participate in vascular surgery fellowship training and those that do not. American Council on Graduate Medical Education data, only available for the years 1999 to 2008, were further used to better understand the changes in number of EVAR and open repairs of AAA performed each year for vascular fellows and general surgery residents, over time.

RESULTS

We identified 449,122 patients (76% men), with 376,355 intact AAAs (84%) and 72,767 ruptured AAAs (16%). Mean age was 75.1 years. Use of EVAR for intact AAA rose to from 35% in 2001 to 63% in 2005 and comprised 78% of repairs by 2008. During the same period, the number of ruptured AAAs decreased by 40% overall, with nonoperative ruptured AAAs decreasing by 29% and EVAR increasing to 31% of rupture repairs. Hospitals training vascular fellows were quicker to adopt EVAR (2-year lag time) for intact AAA and had higher rates of EVAR for ruptured AAA (41.1% vs 29.2%; P = .001) than did hospitals without fellows. Mortality rates for open repairs of intact (4.0% vs 5.0%; P = .01) and ruptured AAA (34.1% vs 41.0%; P = .031) were lower at fellowship hospitals. The average number of open AAA repairs performed by vascular fellows dropped 50% (44.1 to 21.6/year) from 1999 to 2008.

CONCLUSIONS

Contrary to the expectation of a plateau, use of EVAR for intact AAA continues to rise at fellowship and nonfellowship hospitals. Use of EVAR for rupture is being used more often at fellowship programs. The decline in open repairs performed by vascular fellows, and at fellowship and non-fellowship hospitals, may have important implications for future attending experience.

The influence of aneurysm size on anatomic suitability for endovascular repair

OBJECTIVES

It has been proposed that the threshold for repair of abdominal aortic aneurysms (AAAs) suitable for endovascular repair (EVAR) be lowered. A critical step in this pathway is determining whether smaller AAAs are more likely to be anatomically suitable for EVAR; that is, whether suitability is lost as the AAA grows.

METHODS

Patients who underwent ultrasound (US) imaging for asymptomatic AAAs at the University of Rochester Medical Center between January 1, 2003, and January 31, 2007, were identified. All those who had an abdominal/pelvic computed tomography (CT) scan ≤ 3 months of the US imaging were identified. CT scans were reviewed using predefined criteria to assess anatomic suitability for conventional EVAR (ie, without consideration of debranching).

RESULTS

Of 3005 aortic US studies performed during this period, 221 had CT scans showing infrarenal aneurysms. Of these, 168 patients (76%) were candidates for EVAR and 52 (24%) were not, most commonly due to a short neck (40; 77% of excluded). Size measured by CT scanning (mean, 53 ± 11 mm) averaged 4 mm larger than by US imaging (mean, 49 ± 10 mm; r(2) = 0.66; P < .0001). Aneurysm size measured by CT scanning (P < .0001) or US imaging (P < .0001) correlated with anatomic suitability for EVAR. Mean sizes for those suitable were 52 ± 9 mm by CT and 48 ± 7 mm by US imaging, whereas mean sizes for those not suitable were 58 ± 10 mm by CT and 53 ± 8 mm by US imaging. Receiver operating characteristic curve analysis demonstrated that an US cutoff of 4.87 mm best predicted anatomic suitability (86.2% if smaller, 64.8% if larger), whereas a CT cutoff of 57.0 mm best predicted suitability (84.7% if smaller, 63.2% if larger).

CONCLUSIONS

Aneurysm size measured by CT averaged 4 mm larger than by US imaging. Larger aneurysms are less likely to be anatomically suitable for EVAR, but the rate of suitability does not appreciably decrease until the aneurysm measures 49 mm by US imaging or 57 mm by CT scanning. This implies that waiting until the aneurysm reaches currently accepted size criteria for repair does not result in "missing the window" for EVAR; in other words, just as many patients are anatomically suitable for EVAR at currently accepted size cutoffs than if earlier intervention had been done.

AAA stent-grafts: past problems and future prospects

Endovascular aneurysm repair (EVAR) has quickly gained popularity for infrarenal abdominal aortic aneurysm repair during the last two decades. The improvement of available EVAR devices is critical for the advancement of patient care in vascular surgery. Problems are still associated with the grafts, many of which can necessitate the conversion of the patient to open repair, or even result in rupture of the aneurysm. This review attempts to address these problems, by highlighting why they occur and what the failings of the currently available stent grafts are, respectively. In addition, the review gives critical appraisal as to the novel methods required for dealing with these problems and identifies the new generation of stent grafts that are being or need to be designed and constructed in order to overcome the issues that are associated with the existing first- and second-generation devices.

Unique operative approach for dealing with a tortuous external iliac artery during abdominal aortic aneurysm endografting

Endovascular repair of abdominal aortic aneurysms offers many benefits over open repair. However, there are many characteristics that can exclude patients from undergoing this minimally invasive procedure, such as iliac arterial pathology. The present report describes the case of an 85-year-old patient with an aneurysm in which the right external iliac artery presented a challenge for vascular access due to its severe tortuosity and hairpin turn. Access for endovascular repair was achieved via an end-to-end anastomosis of the external iliac artery through a transverse inguinal incision. This represents a new option for achieving endograft placement when confronted with vascular tortuosity.

Dynamic Cine-Computed Tomography Angiography Imaging of Standard and Fenestrated Endografts: Differing Effects on Renal Artery Motion

Different endograft configurations (fenestrated, transrenal, infrarenal) may varyingly affect aortic side branch movement. Renal artery motion was evaluated with 64-slice dynamic cine-computed tomography angiography before and after endovascular aneurysm repair in 16 patients (46 renal arteries). Center-of-mass displacement of the renals was determined per heartbeat for before repair for 3 different endografts; differences were compared, with significance at P < 0.5. Preoperative renal artery motion is significant (1.2 [SD 0.5] mm, range, 0.6-2.). Neither transrenal nor infrarenal endografts alter renal artery motion compared with before repair ( P < .05). Renal artery motion after fenestrated endovascular repair with renal stents reduces motion to 25% of the preoperative value (0.3 [SD, 0.1] mm, range, 0.2-0.5 mm; P = .01). Endograft implantation without stented side branches does not change renal artery motion, potentially allowing significant movement of the renal artery relative to the fenestration. Routine stenting of fenestrations limits postoperative renal artery motion to 0.3 mm, thereby preventing significant branch movement in relation the fenestration.

Visceral and Renal Artery Complications of Suprarenal Fixation during Endovascular Aneurysm Repair

BACKGROUND

The effect of suprarenal fixation of endovascular grafts on renal and visceral artery function remains undefined. This study aimed to determine renal and visceral artery complications following suprarenal fixation during endovascular aneurysm repair (EVR).

METHODS

Prospectively collected data from 112 patients who received suprarenal fixation (group SF) and 36 patients who received infrarenal fixation (group IF) in a single institution from December 1997 to April 2005 were reviewed retrospectively. Median follow-up was 26 months (range 0.1-101 months).

RESULTS

Stent struts extended to or above the level of 106 (94.6%) right renal arteries, 104 (92.9%) left renal arteries, 49 (43.8%) superior mesenteric arteries (SMA), and 7 (6.3%) celiac arteries in group SF. This group had 2 (1.8%) unintentional main renal artery occlusions, of which 1 was successfully treated at the first procedure with a renal stent. There was 1 (0.9%) SMA occlusion which resulted in bowel infarction and death. Group IF had no renal or visceral artery complications. There were no late-onset occlusions or infarcts. There was no significant difference in median serum creatinine between groups SF and IF at 1 month (p = 0.18) and 6 months to 12 months (p = 0.22) follow-up. The change in serum creatinine over time was also not significantly different within each group (SF, p = 0.09; IF, p = 0.38).

CONCLUSIONS

In this study, suprarenal fixation was associated with a very small incidence of immediate renal and visceral artery occlusion. There did not appear to be any medium-term sequelae of suprarenal fixation.

Fenestrated endovascular grafts for juxtarenal aortic aneurysms: A step by step technical approach

Fenestrated endovascular aortic aneurysm repair is a valuable alternative for patients who are at high risk for open surgery, but have unsuitable anatomy for infrarenal endovascular repair due to a short aneurysmal neck. Recognizing that this is an evolving and complex technology, we present a step by step approach to the surgical technique that may be useful for endovascular therapist interested in the management of these complex patients.