Journal of Vascular and Endovascular Therapy

Keywords

Abdominal aortic aneurysm; Endovascular aneurysm repair; Endovascular procedures; Aortic stent graft; Ovation

Introduction

Abdominal aortic aneurysms (AAAs) are potentially lifethreatening anomalies that usually remains asymptomatic until they expand, rupture or burst. At these last stated stages they may cause sudden, severe and constant lower back and abdominal pain. Endovascular aneurysm repair (EVAR) has revolutionized its treatment as well as all areas of the segment; and it is the most common and indicated treatment for AAAs, especially on elective settings [1-4].

Case Report

A seventy-four-year-old male checked in at our hospital complaining of severe abdominal pain. On his physical exam and initial image study, no gastro-intestinal anomalies were found that justified the complaint. The patient was then submitted to an abdominal-pelvic computed tomography angiography (CTA) where was confirmed our previous conjecture of an infrarenal aortic aneurysm with iliac arteries sharply tortuous with close loop and critical angulation (Figure 1). Stands out on the images the following details to be attested for the accomplishment of the procedure; an aortic diameter of 24.4 mm under the lowest right renal artery and a juxtarenal angle of 30°. The aortic neck length with 35 mm, and the lowest renal to aortic bifurcation of 112 mm, iliac arteries diameter length, right and left respectively; 18×120 mm and 16×140 mm.

Figure 1: A mid-infrarenal aortic aneurism, iliac arteries with closed loop and angulation (red arrows).

According to the measurements obtained with CTA we could assess the appropriate diameter and length of the stent graft to be used: one module, a main body of 29×80 mm, and two extensions for iliacs respectively right and left, ipsilateral to the main body 22×120 mm and 18×40 mm contralateral. The ovation stent graft was percutaneously implanted using a sheath 14-F outer diameter (O.D.) under general anesthesia, with total contrast of 65 ml along the procedure which lasted for 90 min, with bilateral femoral access. The endograft main body was introduced from the right side, with no specific reason (given that both iliac arteries were similarly tortuous and angled) then positioned and deployed.

The O-Rings creates a circumferential seal filled with radioopaque polymer. Before filling stent graft with radio-opaque polymer one must be cautious to retract guidewire, then polymer will fill the body of stent graft slowly. In our next step, we confirmed measurements of iliacs extensions using a marker catheter before its release. The final arteriography studies confirmed immediate radiological success of the implanted stent graft with total absence of endoleak. The patient showed clinical improvement right away on postoperative period and he was discharged in 24 h. He was oriented for outpatient return for a follow up and prescribed acetylsalicylic acid (ASA) daily. After one month, we followed with a routine CTA that confirmed the successfulness of surgery showing neither signs of endoleaks nor any undesirable alteration (Figures 2 and 3).

Figure 2: Maximum intensity projection (MIP) reconstruction of the CTA after deployment demonstrated ptfe aortic body graft with lowviscosity radiopaque fill polymer (PABGWL-VRFP- red arrow), proximal seal ring (HA- blue arrow), nitinol supra renal fixation (orange arrow) and bilateral nitinol and ptfe iliac stent graft.

Figure 3: CTA and reverse MIP demonstrated an Ovation abdominal stent graft endoprosthesis, appropriately placed in the infrarenal aortoiliac anatomy demonstrating the final result and radiological success.

Discussion

Advances in medical technology and new generation endoluminal stent grafts are attractive options to treat demanding anatomies [5]. In the presented case we have chosen the Ovation endograft to prevent eventual complications to the iliacs arteries in regard to the challenge encountered from the tortuosity and critical angulation of the bilateral iliac artery. Ovation stent graft system allows access in arteries with very low diameters, therefore, in narrow iliacs arteries, also minimizes vessel trauma due to its ultra-low profile flexible 14-F OD system, additionally enhancing deliverability. Authors published that less than 2% of patients that undergo this procedure with the ovation stent grafts, with in a studied period of a year, was required because iliac limb stenosis or occlusions [6].

Ovation is definitely a device that should surpass the limitations of other prosthesis currently available and is to be considered especially on unusual anatomies eventually found on preoperative studies that will define the planning and conduction to follow. There are significant benefits on the two most important issues of EVAR: access and sealing [6-8].

The mechanism O-Ring circumferential seal allows sealing in infrarenal necks as short as 7 mm, which makes this device ideal to treat aneurysms with aortic neck <10 mm [7-10]. The infra renal neck in our patient was >10 mm and was not challenging in this specific case. Since it was our first experience with ovation device, we chose general anesthesia; however we agreed upon the reading that could be advantageous the use of local anesthesia; being that is a percutaneous procedure [5,7].

Conclusion

The clinical and immediate radiological success of this case suggests that Ovation abdominal stent graft is a promissory option for treatment of abdominal aortic aneurysm with challenging anatomy.

References

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