Endovascular treatment with stenting of celiac artery aneurysms

Abstract

This study aimed to detail the clinical outcomes of patients suffering from celiac arterial aneurysm (CAA) that underwent treatment via stent occlusion.

This is a single-center, retrospective study. A total of 8 consecutive CAA patients were treated via stent occlusion from March 2014 to September 2018 at our hospital. Follow-up computed tomography was conducted after stenting at 1, 3, 6, and 12-month time points and every year thereafter. Both short- and long-term outcomes were assessed.

In total, 8 stents were inserted into these 8 patients, with 2 being uncovered and 6 being covered stents. In 2 patients, stents were positioned in the celiac artery, while in the remaining 6 patients they were placed in the celiac and common hepatic arteries. The median operative duration was 66 minutes. No patients exhibited procedure-associated complications, and the median follow-up duration was 39 months (range: 18–72). Abdominal contrast-enhanced CT analyses of these patients exhibited stent and distal artery patency in 100% of patients, together with CAA obliteration. Visceral necrosis did not occur in any patients over the follow-up period.

Stent occlusion can be safely and effectively used to treat CAA patients.

1. Introduction

More widespread use of abdominal contrast-enhanced computed tomography (CT) imaging has revealed visceral arterial aneurysm (VAA) to be a more common disease than was previously recognized.^[1–3] Between 4.8% and 6.3% of VAA cases present as celiac arterial aneurysm (CAA) cases, which must be urgently treated as their rupture is typically associated with patient death.^[4,5]

A wide range of approaches have been employed to conduct endovascular repair in VAA patients, including ultrasound-guided injection of thrombin, coil embolization, and stent occlusion.^[3–6] These endovascular options are less invasive and less expensive than open surgery, making them preferable in the vast majority of patients. Of these strategies, stent occlusion is the most commonly reported approach to VAA treatment in the literature.^[6–10] In contrast, there have been relatively few studies reporting on stent occlusion and associated outcomes in CAA patients.^[4,5]

In the present study, we discuss clinical outcomes in CAA treatments that underwent stent occlusion treatment at our hospital.

2. Patients and methods

This was a retrospective single-center study that received hospital Institutional Review Board approval. Written consent requirements were waived for this study as a result of its retrospective nature.

2.1. Patients

A total of 8 consecutive CAA patients underwent stent occlusion in our hospital between March 2014 and September 2018 (Table 1). These patients (3 female, 5 male) had a median age of 58.5 years (range: 43–65). Five patients had been suffering from abdominal pain, whereas the other three were asymptomatic, with CAA having been discovered incidentally.

Table 1.

Baseline data.

No./Gender/Age (y)	Surgery history	Involvement	Maximum diameter of CAA (mm)	Symptom
1/Male/65	Yes	CA; CHA	40	Abdominal pain
2/Female/55	No	CA; CHA	32	None
3/Male/43	No	CA; CHA	45	Abdominal pain
4/Male/44	Yes	CA	12	None
5/Female/52	No	CA	29	Abdominal pain
6/Male/62	Yes	CA	14	Abdominal pain
7/Male/62	No	CA	27	None
8/Female/48	No	CA; CHA	28	Abdominal pain

Six patients had hypertension and 3 patients had undergone prior abdominal surgery. No patient experienced abdominal infection.

2.2. CAA diagnosis

Abdominal contrast-enhanced CT imaging was used to diagnose CAA (Fig. 1a). CAA size, shape, and vascular involvement was evaluated prior to stent insertion

Figure 1.

A 62-year-old man with CAA underwent stent insertion. (A) CAA as detected via pre-operative abdominal contrast-enhanced CT imaging. The size of the CAA was 14 x 11 mm. (B) CAA stent insertion using an uncovered stent. There was some contrast-medium flow into the CAA after stent insertion. (C) CT follow-up revealing CAA obliteration and stent patency.

2.3. Stent insertion

Fluoroscopic guidance and local anesthesia were used during all stent insertion procedures in this study. All procedures were performed in the digital substraction angiography room.

The treatment was performed via a right femoral approach. A 5F vascular sheath was inserted into the right femoral artery, a 0.035-inch soft guide wire (Terumo, Tokyo, Japan) and a 4F angiographic catheter (Cordis, NJ, USA) were inserted to the vascular sheath, and the angiographic catheter was placed at the ostium of the celiac artery.

CAA was confirmed via celiac angiography, after which the guide wire was exchanged for 0.035-inch stiff guide wire (Cook, IN, USA). This guide wire was then used to insert a metal stent which was used to seal the CAA (Fig. 1b). Stent selection criteria were: (a) stents had to fully cover the CAA neck (a minimum of 5 mm on both sides), and (b) the stent had a diameter that was 1.1–1.2 times the celiac artery diameter. After stent insertion was complete, patency was confirmed and CAA was reevaluated via celiac angiography.

For 6 months following intervention, all patients underwent dual anti-platelet treatment (aspirin 100 mg/day + clopidogrel 75 mg/day), after which daily aspirin intake was maintained for life.

2.4. Follow-up

Patient follow-up via contrast-enhanced CT was conducted at 1, 3, 6, and 12 months post-operation, and once per year thereafter.

2.5. Definitions

CAA obliteration was defined as no contrast-medium entered into CAA sac on follow-up contrast-enhanced CT. Stent patency was defined as contrast-medium fully flowed through the stent on follow-up contrast-enhanced CT. Re-stenosis was defined as there was a filling defect in stent on the follow-up contrast-enhanced CT.

3. Results

3.1. Treatment

In total, 8 stents were implanted into these 8 patients. Covered stents (Bard, NJ, USA) were used for 6 patients with larger CAAs size (≥ 20 mm), whereas uncovered stents (Medtronic, MN, USA) were used in the 2 remaining patients (Table 2). Both of the 2 patients (No. 4 and 6) had the smaller CAA size (< 20 mm). Furthermore, for patient No. 4, another reason for the choice of uncovered stent was the asymptomatic nature. While for patient No. 6, another reason for the choice of uncovered stent was the narrow CAA neck (3 mm).

Table 2.

Treatment and outcomes.

	Type of stent	Follow-up (mo)	Patency of stent	CAA size (before)	CAA size (after)
1	Covered	72	Yes	40 mm	32 mm
2	Covered	56	Yes	32 mm	26 mm
3	Covered	50	Yes	45 mm	35 mm
4	Uncovered	40	Yes	12 mm	11 mm
5	Covered	38	Yes	29 mm	16 mm
6	Uncovered	32	Yes	14 mm	12 mm
7	Covered	25	Yes	27 mm	26 mm
8	Covered	18	Yes	28 mm	19 mm

The stents used in this study were 8 mm in diameter and 20 to 60 mm in length. The 6 covered stents were self-expandable stents and the 2 uncovered stents were balloon-expandable stents.

In 2 patients, stents were placed in the celiac artery, whereas they were positioned in the celiac and common hepatic arteries in the remaining 6 patients. The median operative duration was 66 minutes (range: 60–90 min), and there were no instances of procedure-associated complications.

CAA obliteration was observed via celiac angiography in the 6 patients treated using covered stents, while reductions in CAA blood flow were evident in the 2 patients treated with uncovered stents.

3.2. Long-term outcomes

The patients in this study were followed for a median of 39 months (range: 18–72). Follow-up abdominal contrast-enhanced CT images confirmed 100% stent and distal artery patency as well as CAA obliteration in all patients (Fig. 1c). All CAAs shrank in size after stent insertion (Table 2). There were no cases of visceral necrosis within the follow-up period.

4. Discussion

Herein, we evaluated the clinical efficacy and long-term outcomes associated with stent insertion for the treatment of CAA. Our results were positive, with patients exhibiting promising short- and long-term outcomes.

While a range of different treatment strategies have been employed to treat VAA and CAA, all of these approaches share the goal of reducing blood flow into the VAA/CAA sac in an effort to prevent its subsequent rupture.^[1–6] Tulsyan et al found that they were able to achieve high rates of technical success (98%) when used coil- or medical glue-mediated embolization to treat 48 VAA patients, while maintaining low rates of postoperative mortality.^[6] Jhajharia et al, in contrast, have reported the use of endoscopic ultrasound-guided thrombin injection to aid in the management of three visceral artery pseudoaneurysm patients, achieving complete pseudoaneurysm closure.^[3] Embolization strategies, however, are only appropriate for the treatment of VAAs with a narrow neck, as a wide neck can lead to leakage of the embolization agent and off-target embolization in other arteries. Certain solid embolic agents additionally have the potential to cause intraoperative aneurysm rupture.

Stent occlusion can be more easily used to treat CAA relative to embolization, and it is associated with lower treatment costs and a reduced risk of intraoperative rupture.^[4,5] Our results demonstrate a 100% technical success rate when using stent occlusion to treat CAA, consistent with previous reports.^[4,5]

These prior studies (Table 3) all utilized covered stents,^{[4,5,11–14]} whereas in the present study we treated 2 patients with uncovered stents owing to the relatively small (< 20 mm) diameter of the CAA neck. Although instant CAA obliteration was not achieved in these patients, long-term follow-up confirmed that CAA obliteration did still eventually occur in both cases. This suggests that uncovered stents can sufficiently slow the flow velocity within the aneurysm sac, thereby creating an environment that is more conducive to thrombus deposition.^[15] Li et al^[16] reported on outcomes in 8 patients that exhibited incompletely sealed aneurysms following stent occlusion. In all 8 of these cases, however, the authors found upon follow-up CT examination that residual endoleak was absent or markedly decreased.^[16]

Table 3.

Previous studies regarding stent repair of CAA.

			Treatment with stent
No.	Year	Patients number	Median CAA size	Type of stents	Median duration	CAA shrinkage or obliteration
Atkins et al[11]	2003	1	10 cm	Covered	Not given	Yes
Atar et al [12]	2004	1	60 mm	Covered	Not given	Yes
Basile et al [13]	2007	1	25 mm	Covered	Not given	Yes
Carrafiello et al [14]	2010	1	Not given	Covered	Not given	Yes
Zhang et al [4]	2016	10	39 mm	All covered	60.5 min	Yes
Xia et al [5]	2019	11	38 mm	All covered	63.2 min	Yes

Both covered an uncovered stents have their advantages and limitations. Covered stents can provide an instant obliteration of the CAA, and therefore, the covered stents were usually used for the large CAA.^[11–14] Compared to the covered stents, bare stents have the mild radial strength and good compliance with the vascular wall.^[17] However, the bare stents cannot completely seal the CAA, and therefore, bare stents were only suit for the small CAA with a narrow neck.

We observed a long-term stent patency rate of 100% in this study, in line with prior findings.^[4,5] This high patency rate is potentially attributable to the regular administration of anti-platelet treatments to these patients following stent insertion.

Even though stents were placed in the celiac and common hepatic arteries in 6 patients in the present study, splenic infarction was not detected in any of these patients upon follow-up evaluation. This suggests that there was sufficient collateral circulation in these patients, thus ensuring that an adequate blood supply was available to the spleen and other abdominal organs.^[18]

There are certain limitations to the present analysis. For one, this was a retrospective study and it is thus inherently susceptible to selection bias. Secondly, this study had a limited sample size making it more challenging to draw any definitive conclusions, particularly as only 2 patients were treated via uncovered stent insertion. Future studies with large sample sizes are thus warranted.

In summary, while further research is required, our results suggest that stent occlusion is a safe, simple, and effective approach to the treatment of patients with CAA.

Author contributions

Data curation: Hai-Lin Xi, Cui Li.

Funding acquisition: Zhi-Long Tian.

Methodology: Fu-Kang Yuan, Rui-Hao Qin, Zhi-Long Tian.

Supervision: Fei Lu.

Writing – original draft: Fu-Kang Yuan.

Writing – review & editing: Fei Lu.