Multicenter experience with a novel flow diverter in visceral aneurysms

Abstract

Purpose

Therapeutic options for the treatment of visceral artery aneurysms (VAA) and pseudoaneurysms (VAPA) include either a surgical or endovascular approach, depending on specific characteristics of both the aneurysm and the individual patient. The therapeutic use of flow diverters (FD) has already yielded excellent results. The purpose of this study is to evaluate initial experiences regarding the use of a novel abdominal FD.

Materials and Methods

In this observational multicenter study, the data of nine consecutive patients with visceral or abdominal aneurysms from four interventional centers, treated with the Derivo peripher FD, between 2022 and 2024 were evaluated regarding the technical feasibility and procedural performance of the device, safety, and treatment outcome.

Results

The average size of the treated aneurysms was 18±11 mm, and the affected vessels were the splenic (55.6%), the hepatic (22.2%), the gastroduodenal (11.1%), and the renal artery (11.1%). Complete aneurysm occlusion was observed in every patient after three months, and mid-term follow-up after 12 months was available for eight patients. All FDs remained patent during the follow-up period. No major complications or adverse events arose. The overall mortality rate was 0%.

Conclusion

Based on our initial multicenter experience, endovascular treatment of abdominal and visceral aneurysms with an FD was found to be effective and safe. The remarkable results in terms of aneurysm occlusion and low complication rates are promising.

Key Points

• The flow diverter was highly effective, achieving complete aneurysm occlusion in all treated patients.

• The procedure had an excellent safety profile, with no major complications, adverse events, or mortality reported and with patency in the follow-up.

• This initial multicenter experience highlights the potential of this endovascular approach as an alternative to traditional surgical methods for managing abdominal and visceral aneurysms.

Citation Format

• Weiss D, Jannusch K, Meier R et al. Multicenter experience with a novel flow diverter in visceral aneurysms. Rofo 2025; DOI 10.1055/a-2599-0801

 

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Zusammenfassung

Ziel

Therapeutische Optionen zur Behandlung von Viszeralarterienaneurysmen (VAA) und Pseudoaneurysmen (VAPA) umfassen einen chirurgischen oder einen endovaskulären Ansatz, abhängig von den spezifischen Merkmalen des Aneurysmas und des jeweiligen Patienten. Bei der Behandlung von zerebralen Aneurysmen existieren bereits sehr gute Ergebnisse für den Einsatz von Flow-Divertern (FD). Ziel dieser Studie ist es, die ersten Erfahrungen mit dem Einsatz eines abdominalen FD auszuwerten.

Materialien und Methoden

Es wurden die Daten von neun konsekutiven Patienten zwischen 2022 und 2024 mit viszeralen oder abdominalen Aneurysmen aus vier interventionellen Zentren ausgewertet, die mit dem Derivo peripher FD behandelt wurden. Dabei wurden die technische Durchführung und der Umgang mit dem Device, die Sicherheit und die Behandlungsergebnisse untersucht.

Ergebnisse

Die durchschnittliche Größe der behandelten Aneurysmen betrug 18±11 mm. Die jeweiligen Trägergefäße waren die Milzarterie (55,6%), die Leberarterie (22,2%) sowie die A. gastroduodenalis (11,1%) und die Nierenarterie (11,1%). Bei allen Patienten wurde ein vollständiger Verschluss des Aneurysmas nach drei Monaten beobachtet und für acht Patienten liegt eine Verlaufskontrolle nach 12 Monaten vor. Alle FD blieben während der Nachbeobachtungszeit durchgängig. Es traten keine beeinträchtigenden Komplikationen oder unerwünschten Ereignisse auf. Die Gesamtmortalitätsrate betrug 0%.

Schlussfolgerung

Basierend auf unseren ersten multizentrischen Erfahrungen erwies sich die endovaskuläre Behandlung von abdominalen und viszeralen Aneurysmen mit einem FD als effektiv und sicher. Die sehr guten Ergebnisse hinsichtlich der Aneurysmaokklusion und der niedrigen Komplikationsraten sind vielversprechend.

Kernaussagen

• Der eingesetzte Flow-Diverter zeigte eine hohe Effektivität und erreichte bei allen behandelten Patienten einen vollständigen Verschluss des Aneurysmas.

• Der Eingriff wies ein sehr gutes Sicherheitsprofil auf, ohne schwere Komplikationen, unerwünschte Ereignisse oder Mortalität. Zudem zeigte sich kein Verschluss eines Flow-diverters.

• Diese erste multizentrische Erfahrung zeigt einen alternativen endovaskulären Ansatz im Vergleich zu anderen endovaskulären oder chirurgischen Behandlungsmethoden von VAA und VAPA auf.

 

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Keywords

aneurysm - endovascular treatment - abdominal - embolization - flow diverter

Introduction

Visceral artery aneurysms (VAA) and pseudoaneurysms (VAPA) are rare conditions. The criteria for the treatment of VAA and VAPA vary due to a lack of randomized controlled trials because of the rarity of the condition. The current recommendations of the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) indicate the following criteria: (1) gastric, gastroepiploic, pancreaticoduodenal, gastroduodenal, mesenteric, or colic VAAs should always be treated regardless of their size due to the high risk of rupture; (2) there is an indication for treatment of symptomatic VAAs as well as (3) VAPAs and (4) VAAs with an increase in size of more than 5 mm/year; (5) ruptured VAPAs and VAAs should be treated immediately; (6) non-ruptured VAAs should be assessed individually (location, size, size increase, patient age, comorbidities; procedural risk) [1]. In this context, the morphology of the aneurysm plays a crucial role in determining the optimal treatment strategy [2] [3] [4].

Therapeutic considerations involve either a surgical or an endovascular approach, depending on the configuration of the aneurysm, the parent vessel, and the patient’s overall health [5] [6]. Established interventional techniques in this regard include coiling, potentially stent- or balloon-assisted, as well as stent-graft delivery [1] [2] [7]. Recent options include the use of flow diverters (FD), a type of stent that leads to long-term occlusion of the aneurysm by modulating the flow while preserving the carrier vessel [8] [9]. This technique has been successfully applied in neuro-interventional aneurysm treatment and was adapted for VAA and VAPA therapy [10] [11]. This approach seeks to replicate the excellent results observed in neurointerventional procedures within the context of VAAs and VAPAs [12] [13]. These devices are specifically designed to redirect blood flow away from the aneurysm, offering a less invasive treatment option than surgery while simultaneously preserving the affected artery and maintaining blood flow to the organ. One explicit advantage of FDs is that side branches can also be stented without closing them. This means that aneurysms on vessel bifurcations or with associated branches can be treated just as well as on vessels without divisions [8] [9].

The aim of this study is to evaluate initial experiences with a novel FD specifically approved for abdominal use, using a multicenter approach to assess therapeutic outcomes, complications, and the operator’s evaluation of the device’s performance in the treatment of VAAs and VAPAs.

 

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Materials and Methods

In this observational multicenter study, the data of nine consecutive patients treated between 2022 and 2024 for VAA or VAPA with a visceral FD across four interventional radiology centers, under the care of four experienced interventional radiologists, were evaluated. Eight patients were treated with the Derivo peripher FD device (AcandisGmbH, Pforzheim, Germany), one patient was treated with a Derivo FD device (AcandisGmbH, Pforzheim, Germany). Both models are identical in construction and the Derivo FD device was used off-label in this patient after extensive informed consent. Anonymized data, including patient files and radiological imaging from the pre-interventional phase to the three-month follow-up, were retrospectively enrolled. Mid-term follow-up after twelve months was conducted for eight patients, with one patient still pending. Ethical approval and the need for informed consent for this study were waived by the local review board at the medical faculty of the University of Düsseldorf due to the retrospective nature of the study.

The primary outcome parameter was the complete occlusion of the aneurysm on follow-up imaging. The secondary outcome parameters included complication rates such as FD occlusion, bleeding, end-organ ischemia, material defects, migration as well as evaluation of technical success by the operator.

Technical aspects of the Derivo peripher flow diverter device

The device is a self-expanding device made of braided nitinol wires, a nickel-titanium alloy, with a titanium core. The braided nitinol wires are weaved densely, so no probing through the struts is possible. It is preloaded on a delivery wire within an introducer and is delivered via a 0.027-inch or 0.039-inch microcatheter, depending on the device size. The flow diverter has a distal transport marker that functions as a point of no return. If the distal marker of the microcatheter is located proximal to the distal transport marker, repositioning of the device is no longer possible. Various device sizes are available ([Table 1]). The device is considered MRI-compatible for 1.5- and 3-Tesla MRI scanners.

Table 1 Available sizes of the Derivo peripher flow diverter device.

Diameter (mm)	Length (mm)	Size of the delivery catheter
5.0	15; 20; 25; 30; 40; 50	0.027-inch
5.5	15; 20; 25; 30; 40; 50
6.0	15; 20; 25; 30; 40; 50
7.0	20; 25; 30; 40; 50	0.039-inch
8.0	20; 25; 30; 40; 50

 

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Procedure description

While the details of endovascular treatment may vary depending on the vessel anatomy and the preferences of the interventionalists, a principal approach is described below. In general, the endovascular procedure was performed under local anesthesia. Access to the vessel was gained via the right common femoral artery using an 8F sheath. After groin puncture, an intravenous bolus of heparin (5,000 IU) was administered. Initially, the target activated clotting time (ACT) was set to 250–300 seconds [8]. However, over time, an ACT of 240 seconds has been found to be sufficient in some cases. A 7F or 8F guiding catheter was then placed into the vessel requiring treatment. A triaxial approach was attempted using an intermediate catheter (e.g., Neurobridge 65, Acandis, Pforzheim, Germany). The FD was delivered through a 0.027-inch or 0.039-inch microcatheter. The appropriate size of the FD was determined based on the diameter of the proximal and distal parent vessel and sizing was performed based on preplanning computed tomography angiography (CTA) scans. The delivery of the FD was guided by fluoroscopy and confirmed with angiography and non-subtracted images. The technical implementation of an FD implantation may be very challenging: the FD is highly flexible and is positioned in the target vessel using a push-and-pull technique [14]. It may be necessary to recapture and reposition the FD if sufficient apposition to the vessel wall cannot be achieved. If, on the other hand, too much pressure is applied to the flexible flow diverter, wrinkles may form, resulting in an increased risk of thrombosis. The decision to use multiple FDs or adjunctive coiling was made at the discretion of the operator. If coiling is performed, this can be done in different ways, depending on factors such as the anatomical characteristics of the aneurysm and the carrier vessel. Coiling can be performed before insertion of the FD, e.g. via a 0.027-inch microcatheter (e.g. Progreat, Terumo, Somerset, New Jersey, USA). Coil embolization can also be done after implantation: as part of a jailing procedure with insertion of a microcatheter into the aneurysm sac and deployment of the FD via a second microcatheter, which secures the base of the aneurysm and stabilizes the first microcatheter in the aneurysm sac. The coil in the aneurysm sac is then detached and the microcatheter is removed without dislocating the FD. As described above, the braided Nitinol wires are woven densely, making any probing besides the struts impossible. The type of coil that is used depends on the anatomical features of the aneurysm and the preferences of the interventionalist (e.g., Nester embolization coil, Cook Medical LLC, Bloomington, Indiana, USA). Following the procedure, patients were monitored postoperatively and transferred to the general ward for further surveillance.

 

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Antiplatelet therapy

Pre-interventional administration included 100 mg/day acetylsalicylic acid (ASA) and 75 mg/day of Clopidogrel, with the latter being administered five days before the intervention and checked with a platelet function test on the day of the procedure. Immediately after treatment, dual platelet therapy with ASA and Clopidogrel was continued at the same doses for at least three months, followed by permanent single antiplatelet treatment with 100 mg/day of ASA. In cases of an insufficient response to either drug as determined by the platelet function test, dose escalation (e.g., clopidogrel 150 mg/day) or substitution with ticagrelor (90 mg/day) was considered [1] [8] [15].

 

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Evaluation of aneurysm occlusion

Follow-up assessments were scheduled early at three months and mid-term at twelve months after the procedure using magnetic resonance angiography (MRA), CTA, or digital subtraction angiography (DSA). DSA was used if more sensitive imaging of possible intimal hyperplasia was required. The early follow-up serves to monitor the progression of aneurysm occlusion. Technically and physiologically, a complete occlusion of the aneurysm is not to be expected immediately, as it would be with coil embolization. Instead, through flow modulation, a continuous occlusion of the aneurysm will occur over time. Additionally, it is important to check the patency of the FD not only after three months, but after twelve months as well, as its substantial material volume may lead to thrombosis, if adequate dual antiplatelet therapy is not maintained [8] [15]. Due to the novelty of the device, there is currently no specific grading scale for abdominal aneurysms. Therefore, the O’Kelly–Marotta (OKM) grading scale was also used for follow-up assessments in this context. The OKM grading scale, commonly utilized for the angiographic evaluation of flow diversion in intracranial aneurysms, was modified (mOKM) and used in control imaging (MRA, CTA, or DSA) for assessing aneurysm occlusion post- procedure and during follow-up [16]. The grading was modified as follows: Grade A represented total filling (>95%); Grade B indicated partial filling (5–95%); Grade C denoted an entry remnant (<5%); and Grade D signified complete occlusion. Favorable aneurysm occlusion was defined as Grade D.

 

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Operator evaluation of Derivo peripher flow diverter device performance

For all cases, the operators completed a questionnaire to assess the technical performance of the FD. The questionnaire covered various aspects, including the transfer of the FD into the microcatheter, trackability through the microcatheter, pushability of the FD, positioning of the FD, deployment, visibility, flexibility, and the apposition of the FD to the vessel wall. Furthermore, if applicable, re-sheathing and re-entering were also evaluated. To this end, a 5-point Likert scale ranging from “- -" (i.e., very poor) to “++” (i.e., very good) was used for evaluation. In addition, the operators had the opportunity to provide individual comments. All procedures were conducted by board-certified interventional radiologists.

 

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Statistical analysis

Due to the small sample size, only descriptive statistical analysis was performed. Categorical variables were presented as numbers and percentages. For metric variables with a normal distribution, means and standard deviations were calculated. Non-normally distributed metric or ordinal variables were reported as medians and interquartile ranges (IQR). Statistical analysis was performed with SPSS software environment (Statistical Package for Social Science, version 24, IBM, Armonk, New York, USA).

 

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Results

Patients

Nine consecutive patients (five women, four men, mean age: 58 ± 15 years) were treated with the FD with the following patterns: Splenic artery in five patients (55.6%) ([Fig. 1]), hepatic artery in two (22.2%), gastroduodenal artery in one (11.1%) ([Fig. 2]), and renal artery in one (11.1%) ([Fig. 3]) patient each ([Table 2]). A VAA was treated in seven cases (77.8%), and a VAPA in two cases (22.2%). The mean maximum diameter of the occluded aneurysms was 18 ± 11 mm, with a mean neck size of 10 ± 0.5 mm. The indication for the treatment of smaller VAAs was based on existing symptoms or progression in size as well as the individual risk profile. Additional coiling was performed in five cases (55.6%) and the aneurysms were partially thrombosed in three cases (33.3%).

Fig. 1 Endovascular treatment of a splenic artery aneurysm with a novel flow diverter. a Axial abdominal computed tomography angiography (CT-A) indicated a 37 mm × 34 mm splenic aneurysm in a 56-year-old male patient. b Reconstruction and sizing of the flow diverter was performed. Before and during the procedure, the patient received double antiplatelet therapy (ASA and Clopidogrel) and i.v. 5000 I.U. heparin. The aneurysm to be treated had a neck size of 8.0 mm and the vessel diameters were 5.2 mm distally and 6.6 mm proximally. c–d An 8.0 × 40 mm Derivo peripher embolization device (Acandis, Pforzheim, Germany) was deployed in the vessel over a NeuroSlider 39 DLC delivery catheter. The proximal end of the device was placed in a slight stenosis. Therefore, a second 8.0 × 30 mm Derivo peripher embolization device (Acandis, Pforzheim, Germany) was deployed to extend the first device. After three months under double antiplatelet therapy, the first follow-up was performed using a CT scan. e–f The aneurysm was completely occluded and therefore clopidogrel was discontinued. The ASA therapy is prescribed for the rest of the patient’s life.

Fig. 2 Endovascular treatment of a gastroduodenal artery aneurysm. a Axial abdominal computed tomography angiography indicated a pseudoaneurysm (VAPA) of the gastroduodenal artery (white arrow); b Angiographic periinterventional images of the VAPA (white arrowhead); c Deployment and successful placement of an 8.0 × 25 mm Derivo peripher embolization device (Acandis, Pforzheim, Germany) with additional coiling of the VAPA.

Fig. 3 Endovascular treatment of a renal artery aneurysm. a Angiographic periinterventional images of a partially thrombosed renal artery aneurysm (black arrow) in a 59-year-old male patient. b Successfully deployed 8.0 × 30 mm Derivo peripher embolization device (Acandis, Pforzheim, Germany) with fully covered aneurysm neck. Partial thrombosis is well delineated as a contrast gap (black arrow). c Control angiography after three months showed complete occlusion of the aneurysm sack (black arrowhead) and a patent flow diverter.

Table 2 Baseline characteristics.

Patient	Sex	Age	Type	Vessel	Aneurysm size	Flow diverter size
VAA = visceral artery aneurysm, VAPA = visceral artery pseudoaneurysm
1	Female	65	VAA	Hepatic artery	35 mm × 20 mm	5 mm × 30 mm
2	Female	81	VAA	Splenic artery	16 mm × 15 mm	6 mm × 40 mm
3	Male	59	VAA	Renal artery	18 mm × 14 mm	8 mm × 30 mm
4	Male	74	VAPA	Hepatic artery	5 mm × 9 mm	6 mm × 40 mm
5	Male	56	VAA	Splenic artery	37 mm × 34 mm	8 mm × 40 mm
6	Female	32	VAA	Splenic artery	10 mm × 10 mm	7 mm × 25 mm
7	Male	60	VAPA	Gastroduodenal artery	9 mm × 10 mm	6 mm × 40 mm
8	Female	39	VAA	Splenic artery	16 mm × 15 mm	5 mm × 25 mm
9	Female	57	VAA	Splenic artery	19 mm × 17 mm	8 mm × 50 mm

 

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Administration of antiplatelet agents

Pre-interventional loading was performed with ASA alone in one patient (11.1%) and with both ASA and Clopidogrel in eight patients (88.9%). Post-interventional antiplatelet therapy was performed with ASA and Clopidogrel for at least three months in all cases and in one case it was continued for six months.

 

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Technical success, safety, and complications

Technical success was achieved in every patient, and after three months, complete aneurysm occlusion was found in all patients based on follow-up imaging using MRA, CTA, or DSA. Twelve-month follow-up revealed that aneurysm occlusion was maintained in all patients with available follow-up (n=8), the flow diverter remained patent, and there were no signs of aneurysm recurrence ([Table 3]). In two cases of a splenic artery aneurysm (e.g., [Fig. 1]), it was necessary to place a second FD. In the first case, this was required because the end of the device resulted in a slight stenosis. In the second case, however, it was due to the shortening of the first FD, and a second was introduced for stability. No device-related procedural complications or adverse events occurred, and all FDs remained patent during follow-up after three months and in all patients with available follow-up after twelve months (n=8). There were no instances of periprocedural embolization of other arteries, end-organ ischemia, or abdominal bleeding. However, there was one case of a false aneurysm of the common femoral artery, which was successfully treated with manual compression and a prolonged compression bandage, without the need for surgical treatment. The overall mortality rate was 0%.

Table 3 Outcome parameters of follow-ups.

Patient	Follow-up at three months			Follow-up at twelve months
	Aneurysm occlusion	Patency of FD	Aneurysm recurrence	Aneurysm occlusion	Patency of FD	Aneurysm recurrence
FD = flow-diverter, n/a = not available
1	Yes	Yes	No	Yes	Yes	No
2	Yes	Yes	No	Yes	Yes	No
3	Yes	Yes	No	Yes	Yes	No
4	Yes	Yes	No	Yes	Yes	No
5	Yes	Yes	No	Yes	Yes	No
6	Yes	Yes	No	Yes	Yes	No
7	Yes	Yes	No	Yes	Yes	No
8	Yes	Yes	No	Yes	Yes	No
9	Yes	Yes	No	n/a	n/a	n/a

 

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Operator evaluation of Derivo peripher flow diverter device performance

On an ordinal rating scale, the device was collectively rated as either "good" or "very good" in terms of transfer into a required 0.027” or 0.039” microcatheter (100%), trackability of FD in microcatheter (88.9%), pushability of FD in microcatheter (88.9%), positioning of FD (77.8%), re-sheathing of FD (100%), deployment of FD (88.8%), reentering of FD (52.5%), overall visibility of FD (85.7%), flexibility (55.6%), and apposition of FD to the vessel wall (33.3%) ([Table 4]).

Table 4 Interventionalists’ individual case-specific experience regarding device performance.

Subject	Very poor	Poor	Mediocre	Good	Very good
Transfer (n=7)	0 (0%)	0 (0%)	0 (0%)	2 (28.6%)	5 (71.4%)
Trackability (n=9)	0 (0%)	0 (0%)	1 (11.1%)	0 (0%)	8 (88.9%)
Pushability (n=9)	0 (0%)	1 (11.1%)	0 (0%)	0 (0%)	8 (88.9%)
Positioning (n=9)	0 (0%)	0 (0%)	2 (22.2%)	2 (22.2%)	5 (55.6%)
Re-sheathing (n=8)	0 (0%)	0 (0%)	0 (0%)	4 (50.0%)	4 (50.0%)
Deployment (n=9)	0 (0%)	1 (11.1%)	0 (0%)	5 (55.6%)	3 (33.3%)
Reentering (n=8)	3 (37.5%)	0 (0%)	0 (0%)	2 (25.0%)	3 (37.5%)
Visibility (n=7)	0 (0%)	0 (0%)	1 (14.3%)	1 (14.3%)	5 (71.4%)
Flexibility (n=9)	0 (0%)	1 (11.1%)	3 (33.3%)	3 (33.3%)	2 (22.2%)
Apposition (n=9)	0 (0%)	1 (11.1%)	5 (55.6%)	1 (11.1%)	2 (22.2%)

The most heterogeneous scores were obtained regarding the apposition of the FD to the vessel wall with five cases of moderate (55.6%) and one case (11.1%) of poor apposition. Furthermore, the flexibility, deployment, and pushability of the FD were rated “poor” in one case each. In three cases (37.5%), re-entering of the FD was rated “very poor”.

 

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Discussion

Flow diversion is an established procedure for the treatment of intracranial aneurysms yet represents a new treatment alternative for VAAs and VAPAs. Although there are only a few case reports available and analyses have been conducted on smaller patient groups, promising results have been achieved regarding the efficacy and safety of visceral flow diversion [8].

In our multicenter approach, we evaluated the efficacy and safety of a novel FD in patients with a VAA or VAPA. Additionally, we assessed the technical handling of the device through an operator evaluation. The use of FD in the treatment of intracranial aneurysms is well-established and has demonstrated high success and low mortality rates [17].

Outcome

We observed complete aneurysm occlusion in all patients (n=9) at the three-month follow-up and in all patients with available follow-up (n=8) at the twelve-month follow-up, which is consistent with the findings reported by Rabuffi et al. as well as Colombi et al. who also used FDs [7] [18]. These high success rates support the effectiveness of this treatment approach. When compared to other angiographic procedures such as the use of covered stent-grafts, our study demonstrates similar success rates [19] [20]. However, due to the rigidity of stent-grafts, their implantation may not be possible in certain anatomical scenarios. Coil embolization may be an alternative procedure but comes with lower success rates and the risk of occlusion of the carrier vessel [21]. On the other hand, coil embolization has the advantage of not requiring antiplatelet therapy [1] [22]. Additionally, occlusion of the carrier vessel, particularly the splenic artery, may not result in splenic infarction due to the presence of numerous collateral vessels, which should be included in the treatment assessment. Surgical approaches exhibit good success rates but involve a much more aggressive approach and are associated with long hospital stays [23]. However, it is crucial to consider that the preservation of the carrier vessel is typically not achieved in the case of surgical therapy, whereas vessel preservation is possible in the case of endovascular therapy, particularly with the use of an FD. This contributes to a reduced risk of bleeding complications and suture insufficiencies [7] [13].

 

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Complication rates

All FDs remained patent with available follow-up after twelve months (n=8), with one patient pending follow-up after twelve months. Furthermore, no device-related procedural complications or adverse events were observed. Neither periprocedural embolization nor end-organ ischemia occurred. Furthermore, there were no bleeding complications and the overall mortality rate was 0%. However, a false aneurysm of the common femoral artery occurred in one case. Although no severe complications occurred in the present study, several have been reported from the use of FDs in the treatment of intracranial aneurysms. These include malposition or migration of the device, particularly in cases of suboptimal sizing, potentially leading to occlusion of the parent vessel or, in rare cases, prolapse into the aneurysm sac. A proximal or distal prolapse, also referred to as a “fish mouth” configuration, may cause flow reduction and subsequent stent thrombosis. Thromboembolic events can also occur when deploying the device, occasionally requiring pharmacological or interventional management. In addition, dissections or perforations of the parent vessel or adjacent branches may occur during placement. While side branches covered by the device usually remain perfused, delayed occlusion remains a potential risk [24] [25]. These low complication rates are in line with the findings of other studies [7] [18]. Compared to other angiographic procedures, such as covered stent-grafts or coil embolization, our study demonstrated lower complication and mortality rates [19] [21]. However, it should be noted that only elective patients were treated in our study. Nevertheless, it has to be considered that the number of patients in the current study is too small to reliably assess complication and mortality rates. Furthermore, the mortality rates for surgical approaches range from 1% to 3%, and they entail longer hospitalization periods due to the considerable trauma associated with the procedure [5] [23]. Among other factors, the cost-effectiveness of endovascular treatment is superior to a surgical approach [26].

 

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Antiplatelet therapy

Pre-interventional loading with ASA alone or in combination with Clopidogrel, as well as post-interventional double platelet therapy with ASA and Clopidogrel for at least three months, followed by permanent single antiplatelet treatment with ASA 100 mg/day was administered to all patients. In one case, dual platelet therapy was continued for six months at the discretion of the interventionalist. The decision to prolong the therapy was made due to safety concerns, considering that this was the first case of treating an abdominal aneurysm with the FD. In the neuro-interventional field, there are still variations regarding antiplatelet therapy without a clear recommendation for one specific approach. Consequently, prospective randomized studies are necessary to establish optimal antiplatelet therapy [27]. Nevertheless, with both approaches employed in our study, no occlusion of the FD was found. Double platelet inhibition is quite severe in comparison to conventional abdominal stents, which is due to the material properties. Compared to other stents, an FD has a relatively high amount of material, which has a thrombogenic effect and must be compensated for by double platelet inhibition. Even innovative antiplatelet coatings of newer FDs based on the current model, which are currently used for cerebral aneurysms, still frequently require double platelet aggregation inhibition [28] [29] [30]. In analogy to the treatment of cerebral aneurysms, the same concept is used here and shows good results regarding aneurysm occlusion and the patency of the FD.

 

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Operator evaluation

Overall, the performance of the FD was rated as good. Heterogeneous results regarding the apposition of the FD as well as poor results in singular cases for flexibility, pushability, and deployment of the FD may be explained on the one hand by the vessel anatomy (elongated and tortuous splenic artery) with increased resistance which required higher forces to advance the FD and on the other hand by the more demanding procedure compared to normal stent implantation [12] [15]. Since this was also the first case of abdominal aneurysm treatment with an FD, one point is particularly crucial here: the treatment method is intricate and requires expertise, underscoring the need for practice and experience using the FD, especially in initial cases. In three cases, re-entering of the FD was rated “very poor” which was due to the vessel anatomy with a sharp curve proximal to the FD.

 

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Limitations

We acknowledge several limitations in this study. First, the number of included patients is limited. However, these findings represent the initial results published on the use of a novel FD in the periphery within a multicenter study. Second, the interventions and materials that were used were subject to the discretion of the interventionalist, resulting in a lack of standardized execution of the procedure. Third, we have only investigated elective treatments, which may introduce a selection bias towards more planned and safer procedures compared to emergency treatment. Fifth, all interventionalists were experienced interventional radiologists with varying degrees of experience regarding the use of flow diverters as part of the multicenter study design. Lastly, the follow-up duration was limited to twelve months in eight patients, preventing conclusive statements regarding the long-term outcome of the therapy.

 

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Conclusion

Endovascular treatment of abdominal and visceral aneurysms with an FD was effective and safe in this first multicenter study. Remarkable results regarding aneurysm occlusion and low complication rates are promising and warrant further investigation in larger multicenter studies.

 

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Conflict of Interest

The authors declare that they have no conflict of interest.

• References

• 1 Rossi M, Krokidis M, Kashef E. et al. CIRSE Standards of Practice for the Endovascular Treatment of Visceral and Renal Artery Aneurysms and Pseudoaneurysms. Cardiovasc Intervent Radiol 2024; 47: 26-35
• 2 Venturini M, Piacentino F, Coppola A. et al. Visceral Artery Aneurysms Embolization and Other Interventional Options: State of the Art and New Perspectives. J Clin Med 2021; 10
• 3 Chaer RA, Abularrage CJ, Coleman DM. et al. The Society for Vascular Surgery clinical practice guidelines on the management of visceral aneurysms. J Vasc Surg 2020; 72: 3s-39s
• 4 Ruffino MA, Rabbia C. Endovascular repair of peripheral and visceral aneurysms with the Cardiatis multilayer flow modulator: one-year results from the Italian Multicenter Registry. J Endovasc Ther 2012; 19: 599-610
• 5 Barrionuevo P, Malas MB, Nejim B. et al. A systematic review and meta-analysis of the management of visceral artery aneurysms. J Vasc Surg 2019; 70: 1694-1699
• 6 Rossi UG, Petrocelli F. Hepatic artery aneurysms: Endovascular therapeutic techniques. Ann Hepatobiliary Pancreat Surg 2021; 25: 167-170
• 7 Rabuffi P, Bruni A, Antonuccio EGM. et al. Treatment of visceral artery aneurysms and pseudoaneurysms with the use of cerebral flow diverting stents: initial experience. CVIR Endovasc 2020; 3: 48
• 8 Semeraro V, Arpesani R, Della Malva G. et al. Flow-diverter treatment for renal artery aneurysms: One-year follow-up of a multicentric preliminary experience. Diagn Interv Radiol 2022; 28: 609-615
• 9 Dibas M, Vivanco-Suarez J, Galecio-Castillo M. et al. Flow Diversion for Intracranial Aneurysms With Incorporated Branch: A Subanalysis From the SEASE International Registry. Stroke: Vascular and Interventional Neurology 2024; 4: e001448
• 10 Murray T, Brennan P, Maingard JT. et al. Treatment of Visceral Artery Aneurysms Using Novel Neurointerventional Devices and Techniques. J Vasc Interv Radiol 2019; 30: 1407-1417
• 11 Sfyroeras GS, Dalainas I, Giannakopoulos TG. et al. Flow-diverting stents for the treatment of arterial aneurysms. J Vasc Surg 2012; 56: 839-846
• 12 Kaschner MG, Kraus B, Petridis A. et al. Endovascular treatment of intracranial “blister” and dissecting aneurysms. Neuroradiol J 2019; 32: 353-365
• 13 Maingard J, Lamanna A, Kok HK. et al. Endovascular treatment of visceral artery and renal aneurysms (VRAA) using a constant mesh density flow diverting stent. CVIR Endovasc 2019; 2: 15
• 14 Ma D, Xiang J, Choi H. et al. Enhanced aneurysmal flow diversion using a dynamic push-pull technique: an experimental and modeling study. AJNR Am J Neuroradiol 2014; 35: 1779-1785
• 15 Spüntrup E, Fares A, Stavrou GA. et al. Behandlung eines großen Aneurysmas der Arteria hepatica propria mit einem Flowdiverter. Gefässchirurgie 2023; 28: 249-254
• 16 O’Kelly C J, Krings T, Fiorella D. et al. A novel grading scale for the angiographic assessment of intracranial aneurysms treated using flow diverting stents. Interv Neuroradiol 2010; 16: 133-137
• 17 Monteiro A, Burke SM, Baig AA. et al. A systematic review and meta-analysis of the Derivo Embolization Device: a novel surface-modified flow diverter for intracranial aneurysm treatment. J Neurointerv Surg 2022; 14: 1125-1129
• 18 Colombi D, Bodini FC, Bossalini M. et al. Extracranial Visceral Artery Aneurysms/Pseudoaneurysms Repaired with Flow Diverter Device Developed for Cerebral Aneurysms: Preliminary Results. Ann Vasc Surg 2018; 53: 272.e271-272.e279
• 19 Venturini M, Marra P, Colombo M. et al. Endovascular Repair of 40 Visceral Artery Aneurysms and Pseudoaneurysms with the Viabahn Stent-Graft: Technical Aspects, Clinical Outcome and Mid-Term Patency. Cardiovasc Intervent Radiol 2018; 41: 385-397
• 20 Rossi M, Rebonato A, Greco L. et al. Endovascular exclusion of visceral artery aneurysms with stent-grafts: technique and long-term follow-up. Cardiovasc Intervent Radiol 2008; 31: 36-42
• 21 Ikeda O, Tamura Y, Nakasone Y. et al. Nonoperative management of unruptured visceral artery aneurysms: treatment by transcatheter coil embolization. J Vasc Surg 2008; 47: 1212-1219
• 22 Weiss D, Jannusch K, Minko P. Viszerale Aneurysmen und Pseudoaneurysmen. Radiologie up2date 2024; 24: 245-261
• 23 Chiesa R, Astore D, Guzzo G. et al. Visceral Artery Aneurysms. Annals of Vascular Surgery 2005; 19: 42-48
• 24 Al-Mufti F, Cohen ER, Amuluru K. et al. Bailout Strategies and Complications Associated with the Use of Flow-Diverting Stents for Treating Intracranial Aneurysms. Interv Neurol 2020; 8: 38-54
• 25 Charbonnier G, Desilles JP, Escalard S. et al. Timing and Spectrum of Neurological Complications After Flow Diverter Implantation for Intracranial Aneurysms. Front Neurol 2021; 12: 590383
• 26 Hogendoorn W, Lavida A, Hunink MG. et al. Cost-effectiveness of endovascular repair, open repair, and conservative management of splenic artery aneurysms. J Vasc Surg 2015; 61: 1432-1440
• 27 Pearce S, Maingard JT, Kuan Kok H. et al. Antiplatelet Drugs for Neurointerventions: Part 2 Clinical Applications. Clin Neuroradiol 2021; 31: 545-558
• 28 Schwab R, Kabbasch C, Goertz L. et al. The DERIVO 2 Heal Embolization Device in the Treatment of Ruptured and Unruptured Intracranial Aneurysms: a Retrospective Multicenter Study. Clinical Neuroradiology 2024;
• 29 Weiss D, Vach M, Ivan VL. et al. Comparison of antithrombogenic coated and uncoated flow diverters in ruptured and unruptured cerebral aneurysms. Journal of Neuroimaging 2025; 35: e13253
• 30 Uysal A, Cay F, Balcı S. et al. Initial Experience with the Derivo 2Heal Flow Diverter under Standard or Reduced-Dose Single Antiplatelet Therapy. AJNR Am J Neuroradiol 2024; 45: 1038-1043

Publication History

Received: 04 December 2024

Accepted after revision: 23 April 2025

Article published online:
21 May 2025