Figura 1. Frontal chest X-ray showing cardiomegaly with elongation of the aortic knob. No signs of ...

Figura 2. A) Coronal reconstruction from abdominal CT angiography showing an infrarenal fusiform ab...

Figura 3. (A) Fluoroscopic positioning of the main body in the infrarenal aorta with proximal stent...

Figura 4. (A) Polymer injection into the sealing rings for adaptation to the aortic neck. (B) Schema...

Figura 5. (A) Snare capture of the metallic guidewire from the contralateral access to establish can...

Figura 6. (A) Cine-angiographic image of the abdominal aorta showing the deployed ALTO® system (End...

Introduction

Endovascular treatment of abdominal aortic aneurysm (AAA) is the preferred strategy for most elderly and high-surgical-risk patients. However, approximately 20-30% of patients present with complex anatomy involving a short or absent infrarenal neck, which is associated with an increased risk of type I endoleak, device migration, and treatment failure.

Polymer-sealed endografts (Ovation iX®/ALTO®, Endologix Inc., Santa Rosa, CA, USA) have shown efficacy in anatomically unfavorable cases, offering sealing independent of neck diameter, low radial force, and reduced reliance on adjunctive techniques.

This case used the ALTO® system in a patient with a non-ideal aortic neck, with no immediate complications and successful sealing.

Clinical case

The patient was an 83-year-old woman with multiple cardiovascular risk factors — advanced age, psychological stress, sedentary lifestyle, hypertension, and prior tobacco use.

Her past medical history included double coronary artery bypass grafting (CABG) with a left internal mammary artery (LIMA) to the anterior descending artery and a vein graft to the obtuse marginal branch of the circumflex artery, requiring intra-aortic balloon counterpulsation; two subsequent strokes without sequels; osteoarthritis; AAA; hypothyroidism; atrial fibrillation on anticoagulation, and moderate left ventricular dysfunction secondary to ischemic-necrotic dilated cardiomyopathy (Figure 1).

A CT angiography showed a 39.8-×-35.9-mm ascending aorta at the subclavian level; a 29.8-×-27.9-mm proximal ascending aorta; and a 37.2-×-32.5-mm distal thoracic aorta. There were signs of mild pulmonary fibrosis and centrilobular and paraseptal emphysema. At the infrarenal level, there was a 64.7-×-56.9-mm aneurysm with mural thrombus, with a proximal neck of only 7 mm from the renal artery origins, extending 103 mm with significant atheromatous involvement of the aortoiliac bifurcation (Figure 2).

Current medications for the patient included digoxin 0.25 mg/day; levothyroxine 100 µg/day (50 µg on Saturdays and Sundays); enalapril 10 mg/day; furosemide; memantine 10 mg/day; acenocoumarol 1 mg/day (2 mg on Wednesdays and Fridays); atorvastatin 10 mg/day; clonazepam 0.5 mg at bedtime; and rupatadine 10 mg/day.

The patient was admitted electively for endograft implantation. Her vital signs on admission were blood pressure, 150/66 mmHg; heart rate, 57 bpm (irregular); respiratory rate, 18 breaths/min; SpO₂ 96% on room air; temperature, 36 °C. The patient was alert and cooperative, with no acute motor or sensory deficits, no angina or anginal equivalents, and no signs of heart failure. Cardiac auscultation revealed S1 and S2 in the 4 standard areas, with a 3/6 holosystolic ejection murmur at the aortic area radiating to the neck. Lung fields were clear bilaterally. The abdomen was soft, non-tender, and non-distended, with normal bowel sounds and a pulsatile periumbilical mass. The lower limbs were symmetric, with no edema and intact peripheral pulses bilaterally.

The ECG showed atrial fibrillation at approximately 65 bpm; electrical axis +90°; QRS 160 ms; QTc 440 ms; right bundle branch block.

The supplementary tests were as follows:

The blood test upon admission showed hematocrit at 41%; hemoglobin 12.6 g/dL; WBC 11,240/µL; platelets 111,800/µL; PT 81%; INR 1.16; aPTT 34 s; glucose 131 mg/dL; BUN 42 mg/dL; creatinine 1.2 mg/dL; total bilirubin 0.8 mg/dL; total protein 6.57 g/dL; AST 18 U/L; ALT 11 U/L; alkaline phosphatase 158 U/L; direct bilirubin 0.2 mg/dL; cholesterol 105 mg/dL; phosphorus 3.76 mg/dL; potassium 4.8 mEq/L; chloride 100 mEq/L; sodium 136 mEq/L; CK 57 U/L; LDH 375 U/L.

A follow-up blood test conducted on June 10 showed hematocrit at 29%; hemoglobin 9.3 g/dL; platelets 77,830/µL; glucose 100 mg/dL; BUN 43 mg/dL; creatinine 1.2 mg/dL; cholesterol 105 mg/dL; total protein 6.96 g/dL; AST 54 U/L; ALT 57 U/L; total bilirubin 0.5 mg/dL; direct bilirubin 0.1 mg/dL; alkaline phosphatase 25 U/L; sodium 135 mEq/L; potassium 5.3 mEq/L; chloride 108 mEq/L.

A cardiac catheterization conducted on August 23, 2019, showed left main coronary artery without significant disease; moderate mid-vessel stenosis in the left anterior descending artery; moderate stenosis in the circumflex artery; severe proximal stenosis in the right coronary artery; left internal mammary artery (LIMA) patent without stenosis; no additional bypass grafts present. One drug-eluting stent (DES) was placed in the right coronary artery.

Procedure

Bilateral inguinal sterile preparation and draping were performed. Sedoanalgesia and spinal anesthesia were administered by the anesthesiology team.

The right common femoral artery was surgically exposed by vascular surgery through a standard layered cutdown. A 7-Fr valved introducer was placed in the left common femoral artery, followed by an 8-Fr introducer in the right common femoral artery. Heparin was administered at 100 IU/kg.

Via left femoral access, a catheter was advanced and an abdominal aortogram was performed to localize the aneurysm and identify the renal artery origins.

Via right femoral access, the main body of the ALTO® 29-mm endograft was advanced and deployed in a stepwise fashion. Following deployment, the polymer kit was prepared (Figure 3) and injected over 14 minutes using auto-injector 2 (Figure 4).

A 0.014-inch guidewire was then advanced, crossed over, and captured using a snare catheter, and withdrawn through the left femoral access (Figure 5). Via this access, a JR catheter was advanced and exchanged for a 0.035-inch wire. The catheter was removed and an Ovation iX® left iliac extension (12 × 140 mm) was advanced and deployed in stepwise fashion. Subsequently, via right femoral access, the right iliac extension (Ovation iX®, 12×120 mm) was advanced and deployed in stepwise fashion.

A completion aortogram was performed, confirming accurate endograft positioning with patent renal arteries and hypogastric vessels (Figure 6).

The procedure was technically successful without complications. All introducers were removed, and the patient was transferred to the intensive care unit.

Discussion

The absence of an adequate aortic neck remains one of the main challenges in endovascular abdominal aortic aneurysm (AAA) repair. A neck is considered “unfavorable” when it has a length < 10–15 mm, angulation >60°, significant thrombus or calcification, or a reverse-tapered (conical) configuration1. In this case, the patient had a 7-mm infrarenal neck — traditionally considered a contraindication to standard EVAR and associated with increased risk of type I endoleak, device migration, and reintervention.

Historically, the therapeutic alternatives for these patients have included open surgical repair, fenestrated EVAR (FEVAR), snorkel/chimney techniques, and, more recently, polymer-sealed endografts (Ovation®/ALTO®). However, open surgery carries significant morbidity in elderly or comorbid patients — as was the case here, given the patient’s advanced age, cardiovascular comorbidities, and overall frailty. Fenestrated and chimney techniques require greater technical complexity, specialized equipment and expertise; they extend operative time and carry increased risks of type I endoleak and renal events.

Growing evidence supports the use of the Ovation and ALTO endoprosthesis devices in patients with short or unfavorable neck anatomy for AAA repair.

The Ovation platform — which includes the ALTO device — features a polymer-filled sealing ring that achieves proximal fixation in necks as short as 7 mm, expanding EVAR eligibility to anatomically complex cases. Multiple studies have shown that the Ovation endograft can achieve technical success and durable proximal sealing in patients with short necks (< 10 mm) and other adverse features (e.g., angulation, reverse taper, thrombus, calcification), with mid- and long-term outcomes comparable to those observed with standard neck anatomy. Of note, 5-year data show no significant increase in type Ia endoleak, reintervention, or aneurysm-related mortality in short-neck cohorts. However, all-cause mortality may be higher in this group, likely reflecting baseline patient risk rather than device failure2-4. The next-generation ALTO device further optimizes proximal sealing by repositioning the polymer rings closer to the renal arteries while maintaining an ultra-low profile, facilitating EVAR within its approved indications in patients with short or unfavorable necks. Early clinical experience with ALTO demonstrates promising technical and clinical success, with no type I/III endoleak or significant migration observed at short-term follow-up5-7. Adjunctive techniques such as aortic balloon molding during Ovation implantation may further optimize outcomes in unfavorable neck anatomy, reducing the need for neck-related additional procedures while maintaining freedom from type Ia endoleak and device migration at one year7.

Both the Ovation and ALTO devices are supported by clinical evidence for use in short and unfavorable-neck AAA, with results suggesting they are viable options for patients who would otherwise not be candidates for standard EVAR2-8.

In this case, the endovascular strategy with ALTO® achieved effective infrarenal sealing without the need for ancillary maneuvers, avoiding high-risk open surgery. Final aortography confirmed adequate renal and hypogastric perfusion, absence of endoleak, and correct polymer expansion — thus demonstrating the safety of this system in challenging anatomy.

This case reinforces that individualized device selection based on patient anatomy, rigorous preoperative planning with three-dimensional CT angiography, and access to advanced endovascular platforms collectively expand the pool of patients eligible for EVAR, offering less invasive alternatives with faster recovery — even in patients who are not candidates for conventional surgery.

In conclusion, the ALTO® endograft is a valid and safe option for the treatment of AAA in cases of absent or unfavorable neck anatomy, supported by growing evidence and consistent clinical outcomes. It should be considered an integral component of the modern endovascular therapeutic toolbox for patients at high surgical risk with challenging anatomy.

Conclusion

In this case, the ALTO® endograft proved to be a safe and effective alternative for the treatment of infrarenal AAA with absent or unfavorable neck anatomy in an elderly high-surgical-risk patient. Polymer-based sealing technology enables extension of EVAR to previously excluded patient populations.

1. Stather PW, Sayers RD, Cheah A, et al. Outcomes of endovascular aneurysm repair in patients with hostile neck anatomy. Eur J Vasc Endovasc Surg. 2012 Dec;44(6):556-61.

2. Mathlouthi A, Khan MA, Al-Nouri O, et al. The Correlation of Aortic Neck Length to Late Outcomes Following EVAR With the Ovation Stent Graft. J Vasc Surg. 2022;75(6):1890-1895.e1.

3. Varkevisser RRB, Patel PB, Swerdlow NJ, et al. The Impact of Proximal Neck Anatomy on the 5-Year Outcomes Following Endovascular Aortic Aneurysm Repair with the Ovation Stent Graft. J Endovasc Ther. 2025;32(3):822-832.

4. de Donato G, Setacci F, Bresadola L, et al. Midterm Results of Proximal Aneurysm Sealing with the Ovation Stent-Graft According to on- Vs Off-Label Use. J Endovasc Ther. 2017;24(2):191-197.

5. Cuozzo S, Martinelli O, Brizzi V, et al. Early Experience with Ovation Alto Stent-Graft. Ann Vasc Surg. 2023; 88:346-353.

6. Gregory M, Metcalfe M, Steiner K. Profile of the Ovation ALTO Abdominal Stent Graft for the Treatment of Abdominal Aortic Aneurysms: Overview of Its Safety and Efficacy. Expert Rev Med Devices. 2021;18(12):1145-1153.

7. Ichihashi S, Takahara M, Fujimura N, et al. Less Aortic Neck Dilatation of the ALTO Stent Graft Compared to the Self-Expanding Stent Grafts After Endovascular Aortic Repair for Abdominal Aortic Aneurysms. Cardiovasc Intervent Radiol. 2025;48(4):438-446.

8. Jensen R, Mathlouthi A, Al-Nouri O.et al. "Aortic Balloon Molding" During Ovation Endograft Implantation Expands Graft Use for Hostile Neck Anatomy. Ann Vasc Surg. 2022; 86:58-67.

Para descargar el PDF del artículo
“Unlucky at neck, lucky at polymer” . Successful endovascular repair of a no-neck infrarenal aneurysm using ALTO Endologix. Case report

Haga click aquí