AAA with a challenging neck: early outcomes using the Endurant stent-graft system. Eur J Vasc Endovasc Surg. 2012;44:274-279. [PMID: 22705160 DOI: 10.1016/j.ejvs.2012.04.031]

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.

Long-term outcomes of the Endurant endograft in patients undergoing endovascular abdominal aortic aneurysm repair

OBJECTIVE/BACKGROUND

To investigate the long-term outcomes after endovascular aneurysm repair (EVAR) in a real-world setting using the Endurant endograft (EG).

METHODS

184 EVAR candidates treated with the Endurant family EGs in a single vascular center were prospectively enrolled from January 2009 to December 2016. Kaplan-Meir estimates of long-term standardized primary and secondary outcome measures were performed. Per protocol, subgroup comparison analysis was performed in three groups: patients treated within instructions for use (in-IFU) vs patients treated outside IFU (outside-IFU), EVAR in patients receiving the Endurant proximal diameter 32 or 36 mm EG vs those receiving the <32 mm diameter EG and EVAR with various Endurant EG versions.

RESULTS

The mean follow-up was 75.09 ± 37.9 months (range: 4.1-172 months). The median age of the patients was 72.96 ± 7.03 years (range: 55-88 years). A total of 177 patients were male (96.2%). Compliance with IFU was followed in 107 patients (58.2%). Overall survival was 69.5% and 48% at 5 and 8 years, respectively. Of the 102 all-cause deaths, 7 (6.9%) were aneurysm related. Six of these postimplant deaths occurred in patients presented with aneurysm rupture from type Ia or/and type Ib endoleak. At 5, 8, and 10 years of observation, freedom from aneurysm rupture, open surgical conversion, type I/III endoleak, any type of endoleak, aneurysm-related secondary intervention probabilities, and neck-related events were as follows: 98.1%, 95%, and 89.4%; 95.1%, 91.2%, and 85.7%; 93.6%, 87.3%, and 83.9%; 83.4%, 74%, and 70.9%; 89.8%, 76.7%, and 72%; and 96.3%, 90%, and 87.6%, respectively. Corresponding clinical success was 90%, 77.4%, and 68.4%, respectively. Patients treated outside-IFU had significantly higher risk of aneurysm rupture, open surgical conversion probability, occurrence of type I/III endoleak, and chance of reinterventions and lower clinical success probabilities compared with the in-IFU counterparts at 5 and 8 years. This statistical difference remained when type Ia endoleak or endoleak of any type was considered independently. In addition, it was stronger in patients having extreme anatomic boundaries (>1 hostile anatomic condition), when aneurysm-related death, aneurysm rupture, and clinical success at 5 years were considered. Overall proximal migration and limb occlusion were recorded in 1.1% and 4.9% of the patients, respectively. Overall reintervention rate was 17.4%. An increase in aneurysm sac diameter was observed in 12.5% of patients and was not related to IFU status. The Endurant version or the proximal EG diameter had no significant association with the chance of any complication or adverse event.

CONCLUSIONS

The data confirmed the durability of the Endurant EG, achieving promising long-term outcomes in a real-world setting. However, its positive performance must be interpreted with caution in patients treated off-label especially those with extreme anatomic boundaries. In this cohort, some of EVAR advantages might be lost in the late future. Further similar studies are warranted.

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

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

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

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

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Endovascular Aortic Repair with the "Step-by-Step" Deployment of the Endurant Stent-Graft System in Severe Neck Angulation: Technique and Review of the Literature

OBJECTIVES

To describe a new technique based on a different deployment of the Endurant Stent-Graft System (Medtronic Cardiovascular, Santa Rosa, CA) during endovascular aortic aneurysm repair to guarantee a more precise deployment in presence of severe neck angulation (SNA).

TECHNIQUE

The "step-by-step" deployment technique consists of an alternate partial release of the main body and of the free-flow suprarenal stents to approximate the radiopaque markers of the graft fabric to the aortic wall, obtaining a more precise delivery, reducing the possibility of downward dislodgments along the external curve of the infrarenal angle and asymmetrical deployments in presence of SNA.

CONCLUSIONS

The "step-by-step" technique is a simple, safe, and effective graft-deployment method, which allows a very precise release in SNA and possibly achieves better results in the long-term period in such difficult anatomies.

Endurant stent graft demonstrates promising outcomes in challenging abdominal aortic aneurysm anatomy

OBJECTIVE

We aimed to assess the 5-year safety and effectiveness outcomes of patients enrolled in the Endurant Stent Graft Natural Selection Global Post Market Registry (ENGAGE) who were treated outside the approved indications for use (IFU) of the Endurant stent graft.

METHODS

Our primary outcome measure was 12-month treatment success, defined as successful endograft delivery and deployment and the absence of type I or III endoleak, stent migration or limb occlusion, late conversion, and abdominal aortic aneurysm diameter increase or rupture. Secondary outcome measures included 30-day all-cause mortality, major adverse events, secondary procedures, technical observations, aneurysm-related mortality, and all-cause mortality within 12 months.

RESULTS

Demographic characteristics of ENGAGE patients treated outside (225 [17.8%]) and within (1038 [82.2%]) the IFUs were similar, except that female patients comprised a much higher percentage of the outside IFU group (19.1% vs 8.7%; P < .001). The outside IFU group presented with lower rates of coronary artery disease and cardiac revascularization and a greater number of symptomatic patients compared with the within IFU group (21.3% vs 15.0%; P = .020). Technical success was achieved in more than 99% of all patients. The outside and within IFU groups showed a comparable and low occurrence of uncorrected type I (0.9% vs 1.2%; P = 1.00) and type III endoleak (0.4% vs 0.3%; P = .54) immediately after device implantation. The 5-year freedom from type IA endoleaks was 89.4% vs 96.7% (P < .0001) for those patients outside and within the IFUs, respectively, although both groups had similar type III endoleaks through 5 years (P = .61). Stent graft limb occlusion estimated overall survival, and freedom from aneurysm-related mortality and endovascular interventions were comparable in both patient groups through the 5-year follow-up. The Kaplan-Meier estimates at 5 years showed a trend for low but increased need for type I or III endoleak correction procedures in the outside IFU group compared with the within IFU group (7.2% vs 5.2%; P = .099).

CONCLUSIONS

Differences were not observed in all-cause mortality, aneurysm-related mortality, and secondary procedures between within and outside IFU patients through a 5-year follow-up in the ENGAGE registry. Proximal necks with angulation or diameters outside the IFUs were the most common reasons for patients identified as being outside IFU, and the cohort had increased incidence of type IA endoleaks. Despite the challenges presented from the broad range of aortic and abdominal aortic aneurysm morphologies, the Endurant stent graft showed promising 5-year outcomes.

Validation of a New Methodology to Determine 3-Dimensional Endograft Apposition, Position, and Expansion in the Aortic Neck After Endovascular Aneurysm Repair

Purpose: To validate a novel methodology employing regular postoperative computed tomography angiography (CTA) scans to assess essential factors contributing to durable endovascular aneurysm repair (EVAR), including endograft deployment accuracy, neck adaptation to radial forces, and effective apposition of the fabric within the aortic neck. Methods: Semiautomatic calculation of the apposition surface between the endograft and the infrarenal aortic neck was validated in vitro by comparing the calculated surfaces over a cylindrical silicon model with known dimensions on CTA reconstructions with various slice thicknesses. Interobserver variabilities were assessed for calculating endograft position, apposition, and expansion in a retrospective series of 24 elective EVAR patients using the repeatability coefficient (RC) and the intraclass correlation coefficient (ICC). The variability of these calculations was compared with variability of neck length and diameter measurements on centerline reconstructions of the preoperative and first postoperative CTA scans. Results: In vitro validation showed accurate calculation of apposition, with deviation of 2.8% from the true surface for scans with 1-mm slice thickness. Excellent agreement was achieved for calculation of the endograft dimensions (ICC 0.909 to 0.996). Variability was low for calculation of endograft diameter (RC 2.3 mm), fabric distances (RC 5.2 to 5.7 mm), and shortest apposition length (RC 4.1 mm), which was the same as variability of regular neck diameter (RC 0.9 to 1.1 mm) and length (RC 4.0 to 8.0 mm) measurements. Conclusion: This retrospective validation study showed that apposition surfaces between an endograft and the infrarenal neck can be calculated accurately and with low variability. Determination of the (ap)position of the endograft in the aortic neck and detection of subtle changes during follow-up are crucial to determining eventual failure after EVAR.

Abdominal aorta aneurysm with hostile neck: Early outcomes in outside instruction for use in patients using the treovance® stent graft

Purpose:

The efficacy and safety of endovascular aneurysm repair (EVAR), in patients outside instruction for use (IFU), is very challenging and widely debated. The aim of this study was to evaluate the placement of the Treovance^® abdominal aorta stent-graft in patients with hostile proximal necks considered outside IFU.

Materials and Methods:

Between May 2013 and August 2014, 5 patients with outside IFU underwent EVAR with the Treovance^® stent-graft. Technical and clinical successes were evaluated. All 5 patients underwent clinical and imaging follow-up.

Results:

Technical and clinical successes were achieved in all 5 patients without adjunctive endovascular procedures or surgical conversion. During the mean follow-up of 21 months, no type I/III endoleaks, stent-graft migration nor kinking/occlusion were observed. In all 5 patients, a reduction of the proximal neck angle was observed.

Conclusion:

In our small series of selected outside IFU patients, EVAR with the Treovance^® stent-graft was technically feasible and safe, with satisfactory short-term follow-up results, when performed by experienced operators. Long-term follow-up will be necessary to confirm the durability of our preliminary promising results.

Incidental extravascular findings in computed tomographic angiography for planning or monitoring endovascular aortic aneurysm repair: Smoker patients, increased lung cancer prevalence?

AIM

To validate the feasibility of high resolution computed tomography (HRCT) of the lung prior to computed tomography angiography (CTA) in assessing incidental thoracic findings during endovascular aortic aneurysm repair (EVAR) planning or follow-up.

METHODS

We conducted a retrospective study among 181 patients (143 men, mean age 71 years, range 50-94) referred to our centre for CTA EVAR planning or follow-up. HRCT and CTA were performed before or after 1 or 12 mo respectively to EVAR in all patients. All HRCT examinations were reviewed by two radiologists with 15 and 8 years’ experience in thoracic imaging. The results were compared with histology, bronchoscopy or follow-up HRCT in 12, 8 and 82 nodules respectively.

RESULTS

There were a total of 102 suspected nodules in 92 HRCT examinations, with a mean of 1.79 nodules per patient and an average diameter of 9.2 mm (range 4-56 mm). Eighty-nine out of 181 HRCTs resulted negative for the presence of suspected nodules with a mean smoking history of 10 pack-years (p-y, range 5-18 p-y). Eighty-two out of 102 (76.4%) of the nodules met criteria for computed tomography follow-up, to exclude the malignant evolution. Of the remaining 20 nodules, 10 out of 20 (50%) nodules, suspected for malignancy, underwent biopsy and then surgical intervention that confirmed the neoplastic nature: 4 (20%) adenocarcinomas, 4 (20%) squamous cell carcinomas, 1 (5%) small cell lung cancer and 1 (5%) breast cancer metastasis); 8 out of 20 (40%) underwent bronchoscopy (8 pneumonia) and 2 out of 20 (10%) underwent biopsy with the diagnosis of sarcoidosis.

CONCLUSION

HRCT in EVAR planning and follow-up allows to correctly identify patients requiring additional treatments, especially in case of lung cancer.

Endovascular Aneurysm Repair in Patients with Conical Neck Anatomy

PURPOSE

Cone shape neck is regarded as non-instruction for use (IFU) in most commercial stent graft. However, in real practice, liberal application of endovascular aneurysm repair (EVAR) for outside of IFU happens. We investigate non-adherence to conical neck anatomy in terms of early aneurysmal exclusion results.

MATERIALS AND METHODS

From January 2010 to December 2013, 105 patients with abdominal aortic aneurysm (AAA) underwent EVAR in Daegu Catholic University Medical Center. Among them, 38 patients (36.2%) had AAA with conical neck. We investigated the clinical characteristics of patients and the details of conical neck. We also analyzed the clinical results, such as endoleak, migration, procedure failure, perioperative mortality, and admission duration between conical neck and non-conical neck.

RESULTS

The maximum diameter of AAA was larger (60.95 mm vs. 52.68 mm, P=0.016) and the infrarenal neck length was shorter (25.07 mm vs. 38.13 mm, P=0.000) in conical neck group. During the procedure, type Ia endoleak occurred more in conical neck group (23.7% vs. 6.0%, P=0.013) and it could be successfully solved with additional adjunctive treatments, such as balloon or Palmaz stent. Although there was no statistical significance, mortality was higher and admission duration was longer in the conical neck (15.8% vs. 6.0%, 16.62±13.12 days vs. 13.03±13.13 days). Mean follow-up duration was 319.2±366.45 days. Successful aneurysmal exclusion was achieved.

CONCLUSION

The presence of conical neck may not be a contraindication for EVAR. However, conical neck requires careful observation for additional adjunctive treatments because it increases the risk of type Ia endoleak.

Predeployed aortic extension cuff (kilt) in EVAR with hostile neck anatomy using Endurant II system: preliminary results

INTRODUCTION

Various modifications of standard endovascular aortic aneurysm repair (EVAR) have been developed to solve the problem of difficult neck anatomy.

AIM

The authors propose the implantation of a predeployed extension cuff (kilt) using on-shelf Endurant II elements. In a vast majority of cases, the proposed method provides a solution for the hostile neck problem using standard Endurant II elements available in all centers performing subrenal EVAR procedures.

MATERIAL AND METHODS

The early outcomes of kilt implantation were evaluated in 11 patients (three with ruptured abdominal aortic aneurysms, one symptomatic) in 2 vascular centers in Silesia (Poland). All patients presented with hostile neck anatomy defined as neck length < 10 mm, diameter > 28 mm, angulation > 60°, mural thrombus or calcium > 2 mm in thickness or > 180° circumference.

RESULTS

No intraoperative type I endoleak or device migration was observed. Two perioperative deaths occurred in patients in a severe condition with ruptured aneurysms. One case of type III endoleak was managed by the implantation of an additional iliac extension with complete endoleak sealing.

CONCLUSIONS

The proposed method seems to be effective in early endoleak prevention in patients with hostile neck anatomy undergoing EVAR procedures; however, studies with long-term follow-up are needed.

Follow-up of endovascular aortic aneurysm repair: Preliminary validation of digital tomosynthesis and contrast enhanced ultrasound in detection of medium- to long-term complications

AIM: To validate the feasibility of digital tomosynthesis of the abdomen (DTA) combined with contrast enhanced ultrasound (CEUS) in assessing complications after endovascular aortic aneurysm repair (EVAR) by using computed tomography angiography (CTA) as the gold standard.

METHODS: For this prospective study we enrolled 163 patients (123 men; mean age, 65.7 years) referred for CTA for EVAR follow-up. CTA, DTA and CEUS were performed at 1 and 12 mo in all patients, with a maximum time interval of 2 d.

RESULTS: Among 163 patients 33 presented complications at CTA. DTA and CTA correlated for the presence of complications in 32/33 (96.96%) patients and for the absence of complications in 127/130 (97.69%) patients; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of DTA were 97%, 98%, 91%, 99%, and 98%, respectively. CEUS and CTA correlated for the presence of complications in 19/33 (57.57%) patients and for the absence of complications in 129/130 (99.23%) patients; the sensitivity, specificity, PPV, NPV and accuracy of CEUS were 58%, 99%, 95%, 90%, and 91%, respectively. Sensitivity, specificity and accuracy of combining DTA and CEUS together in detecting EVAR complications were 77%, 98% and 95%, respectively.

CONCLUSION: Combining DTA and CEUS in EVAR follow-up has the potential to limit the use of CTA only in doubtful cases.

Outcomes of Endurant stent graft in narrow aortic bifurcation

OBJECTIVE

The purpose of this study was to compare the outcomes obtained with Endurant stent graft in the early and midterm period in the treatment of patients with narrow aortic bifurcation vs patients with standard aortic bifurcation.

METHODS

Data were prospectively collected from 817 patients with abdominal aortic aneurysm treated between November 2007 and August 2014 with the Endurant stent graft at our center. There were 87 patients (10.6%) with a narrow aortic bifurcation (≤20 mm; NA group). The remaining 730 patients (89.4%) had a standard aortic bifurcation (SA group). Early and estimated 3-year outcomes were evaluated in these patients in terms of survival, freedom from any device-related reinterventions, and freedom from graft thrombosis. Univariate and multivariate analyses in the NA group were performed to detect possible predictors for poor outcomes.

RESULTS

The two groups were similar in terms of demographics, preoperative diagnostic assessment, and intraoperative data. In 211 of 817 patients (25.8%), an adjunctive iliac limb stenting by balloon-expanding stents was performed. Overall, 41 patients in the NA group (47.1%) underwent iliac limb stenting, whereas an iliac stent was implanted in just 170 patients (23.3%) in the SA group (P < .001). The mean follow-up was 16.3 months (range, 1-73 months). The estimated 3-year survival rate was similar between the two groups (87.2% in the NA group vs 80.8% in the SA group; P = .84). Furthermore, the estimated freedom from any device-related reinterventions was 92.9% in the NA group and 85.5% in the SA group (P = .1). Finally, the estimated 3-year freedom from graft thrombosis was 96.9% in the NA group and 94.8% in the SA group (P = .79). In the NA group at univariate and multivariate analyses, none of the examined preoperative or intraoperative factors were independent predictors of poor outcomes.

CONCLUSIONS

Use of bifurcated Endurant stent graft, combined in almost half of the patients with narrow aortic bifurcation with additional aortoiliac stent placement, is feasible and safe. Early and midterm outcomes are similar to those obtained in non-narrow aortic bifurcation.

An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents

Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.

Troubleshooting techniques for the Endurant™ device in endovascular aortic aneurysm repair

Endovascular aortic aneurysm repair with the Endurant™ stent-graft system has been shown to be safe and effective in high-risk surgical patients with complex suprarenal and/or infrarenal abdominal aortic aneurysm anatomy. The wireformed M-shaped stent architecture and proximal springs with anchoring pins theoretically permit optimal sealing in shorter and more angulated proximal aneurysm necks even under off-label conditions. Nonetheless, extremely difficult anatomical situations and inherent graft system-related limitations must be anticipated. Herein, we describe our techniques to overcome the capture of the tip sleeve within the suprarenal bare-stent anchoring pins, other endograft segments, and native vessels.

Standard endovascular treatment of abdominal aortic aneurysms in patients with very short proximal necks using the Endurant stent graft

OBJECTIVE

This study evaluated and compared the midterm results of endovascular aortic aneurysm repair with the Endurant (Medtronic Inc, Santa Rosa, Calif) stent graft system in off-label use in patients with short (<10 mm) proximal aortic necks and in patients treated according to device-specific instructions for use.

METHODS

This was a case-control (2:1) single-center retrospective analysis of prospectively collected data performed between September 2008 and December 2012. Analysis identified 19 elective patients with short (<10 mm) proximal necks and mild angulations (≤45°) treated with the Endurant stent graft and 38 patients matched for age, sex, and aneurysm diameter with proximal aortic necks ≥10 mm in length who met the instructions for use. End points included technical and clinical success and freedom from any secondary intervention, any type of endoleak, and aneurysm-related death.

RESULTS

The short-neck group was a mean ± standard deviation age of 71.7 ± 8.9 years, 84% were men, and their mean infrarenal aortic neck length was 6.1 ± 1.2 mm. Mean suprarenal and infrarenal angles were 110° ± 10.4° and 170° ± 15.4°, respectively. Aortic neck diameters were similar between the groups (26.6 ± 3.8 vs 25.7 ± 3.7 mm; P = .36). Primary technical success was achieved in all cases. Off-label patients were more likely to require additional proximal cuff deployment to successfully obtain a seal (21% vs 3%; P = .04). The two patient groups were similar in rates of perioperative mortality, morbidity, and complications. Mean follow-up of 24 ± 12 months revealed no differences in clinical success, freedom from reintervention, and aneurysm-related death. No type I endoleaks were observed in either group during the follow-up period.

CONCLUSIONS

The Endurant stent graft system applied off-label in patients with very short aneurysm necks (<10 mm) with mild angulation showed acceptable treatment results. These midterm results might suggest its use in carefully selected patients with very short neck anatomy. Long-term data are needed to verify the observed durability of the Endurant stent graft.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Rescue EVAR for ruptured AAA: Clinical success does not mean technical success

We report a clinical evolution of a 85-years old male admitted to our Emergency Department for ruptured abdominal aortic aneurysm (rAAA). One month later a huge type I proximal endoleak was detected and corrected by proximal aortic extension. We decided to fix the stent-graft to the aortic wall using EndoAnchors. However, an asymptomatic type III endoleak due to controlateral limb disconnection was detected at the followed schedulated CT angio and corrected by a relining of the endograft. The patient is now in good clinical condition with no evidence of endoleaks at 1-year follow-up.

Aortic dissection occurring 18 months after successful endovascular repair in an anatomically difficult case of abdominal aortic aneurysm

We report an autopsy case of aneurysm dissection that occurred 18 months after the implantation of a Zenith stent graft. A 94-year-old woman, who had undergone an endovascular repair with postoperative reintervention, died of shock due to retroperitoneal hematoma. An autopsy indicated that the stent graft remained firmly fixed to the native aorta, whereas the dissection occurred near the proximal edge of the stent graft but not at the point of attachment between the suprarenal stent hook and the aorta. The luminal surface of the stent graft was almost completely covered with a transparent film with an endothelial cell lining, which might reflect the tissue regeneration observed on histological examination. This was a rare case of acute aortic dissection that occurred 18 months after EVAR, in which the autopsy indicated interesting microscopic findings and the mechanisms underlying the aortic dissection. We believe that aggressive reintervention at the proximal site in elderly women might cause the dissection of the native aorta.

The role of US examination in the management of acute abdomen

Acute abdomen is a medical emergency, in which there is sudden and severe pain in abdomen of recent onset with accompanying signs and symptoms that focus on an abdominal involvement. It can represent a wide spectrum of conditions, ranging from a benign and self-limiting disease to a surgical emergency. Nevertheless, only one quarter of patients who have previously been classified with an acute abdomen actually receive surgical treatment, so the clinical dilemma is if the patients need surgical treatment or not and, furthermore, in which cases the surgical option needs to be urgently adopted. Due to this reason a thorough and logical approach to the diagnosis of abdominal pain is necessary. Some Authors assert that the location of pain is a useful starting point and will guide a further evaluation. However some causes are more frequent in the paediatric population (like appendicitis or adenomesenteritis) or are strictly related to the gender (i.e. gynaechologic causes). It is also important to consider special populations such as the elderly or oncologic patients, who may present with atypical symptoms of a disease. These considerations also reflect a different diagnostic approach. Today, surely the integrated imaging, and in particular the use of multidetector Computed Tomography (MDCT) has revolutionised the clinical approach to this condition, simplyfing the diagnosis but burdening the radiologists with the problems related to the clinical management. However although CT emerging as a modality of choice for evaluation of the acute abdomen, ultrasonography (US) remains the primary imaging technique in the majority of cases, especially in young and female patients, when the limitation of the radiation exposure should be mandatory, limiting the use of CT in cases of nondiagnostic US and in all cases where there is a discrepancy between the clinical symptoms and negative imaging at US.

An optimal combination for EVAR: low profile endograft body and continuous spiral stent limbs

AIM

to evaluate the outcomes of EVAR performed with a new generation of bifurcated endografts and limbs.

METHODS

prospectively collected data from fifty consecutive patients with abdominal aortic aneurysms (AAA) treated at our institution with a Low Profile Zenith(®) bifurcated body/Zenith(®) Spiral-Z legs combo were analysed. AngioCT scans and Ultrasound exams were performed prior to discharge. Ultrasound examination was repeated 6 months after the procedure to assess endograft patency and to depict endoleaks

RESULTS

Median age was 70.6 years [50-88] and median ASA score was 3 [2-4]. Median aortic diameter was 56 mm [49-81]. Of the 100 external iliac access vessels, 14 had a diameter of 6 mm or lower. All endografts were successfully implanted. Post-operative Ultrasound examination and angioCT scan depicted both 1 type Ia, and 10 and 19 type 2 endoleaks respectively. An asymptomatic thrombosis of the left external iliac artery distal to the endograft limb was also depicted. 30-day mortality rate was 0%. Two patients died respectively three and four months after EVAR. Both deaths were not aneurysm related. All patients underwent an ultrasound exam 6-12 months after EVAR. All endografts main bodies and limbs were patent. Five endoleaks were depicted, all were type II endoleaks (the early type Ia endoleak had sealed spontaneously; it was confirmed by an angioCT scan). One patient presented a significant stenosis of the left iliac limb at the level of a narrow and calcified aortic bifurcation. It was successfully treated by bilateral iliac angioplasty and kissing balloon stenting.

CONCLUSIONS

EVAR performed with the Zenith LP main body in combination with Spiral-Z Iliac Legs is safe and effective. No limb occlusions were diagnosed at the 6 month follow up even in challenging iliac anatomies usually considered as contra indications for EVAR. Our first results are most satisfying and calling to be completed by a longer follow up.