Radiol Oncol 2024; 58(2): 206-213. doi: 10.2478/raon-2024-0021
206
research paper
Long-term outcome of multilayer flow 
modulator in aortic aneurysms
Karlo Pintaric1,2, Lucka Boltezar3,4, Nejc Umek5, Dimitrij Kuhelj1,4
1 Clinical Institute of Radiology, University Medical Center Ljubljana, Slovenia
2 Department of Radiology, Faculty of Medicine, University of Ljubljana, Slovenia
3 Department of Medical Oncology, Institute of Oncology Ljubljana, Slovenia
4 Faculty of Medicine, University of Ljubljana, Slovenia.
5 Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Slovenia
Radiol Oncol 2024; 58(2): 206-213.
Received 12 January 2024 
Accepted 20 February 2024
Correspondence to: Assoc. Prof. Dimitrij Kuhelj, M.D., Ph.D., Clinical Institute of Radiology, University Medical Center Ljubljana, Zaloška 7, 
SI-1000 Ljubljana, E-mail: dimitrij.kuhelj@kclj.si
Disclosure: No potential conflicts of interest were disclosed. 
This is an open access article distributed under the terms of the CC-BY license (https://creativecommons.org/licenses/by/4.0/).
Background. This retrospective study investigated the efficacy of endovascular treatment with multilayer flow modu-
lators (MFMs) for treating aortic aneurysms in high-risk patients unsuitable for conventional treatments. 
Patients and methods. Conducted from 2011 to 2019 at a single center, this retrospective observational study in-
cluded 17 patients who underwent endovascular treatment with MFMs. These patients were selected based on their 
unsuitability for traditional surgical or endovascular procedures. The study involved meticulous pre-procedural plan-
ning, precise implantation of MFMs, and follow-up using CT angiography. The primary focus was on volumetric and 
flow volume changes in aneurysms, along with traditional diameter measurements. Moreover, the technical success 
and post-procedural complications were also registered.
Results. The technical success rate was 100%, and 30-day procedural complication rate was 17.6%. Post-treatment 
assessments revealed that 11 out of 17 patients showed a decrease in flow volume within the aneurysm sac, indicative 
of a favorable hemodynamic response. The median decrease in flow volume was 12 ml, with a median relative de-
crease of 8%. However, there was no consistent reduction in aneurysm size; most aneurysms demonstrated a median 
increase in volume for 46 ml and median increase in diameter for 18 mm. 
Conclusions. While MFMs offer a potential alternative for high-risk aortic aneurysm patients, their effectiveness in pre-
venting aneurysm expansion is limited. The results suggest that MFMs can provide a stable hemodynamic environment 
but do not reliably reduce aneurysm size. This underscores the need for ongoing vigilance and long-term monitoring 
in patients treated with this technology.
Key words: multilayer flow modulator; aortic aneurism; long-term follow up; volumetric measurements
Introduction
Endovascular management of aortic aneurysms 
with stent grafts has been possible for over 30 
years. One of the challenges of the procedure is the 
preservation of flow in the aortic branches and the 
prevention of ischaemia. There have been many at-
tempts to overcome this problem, including using 
fenestrated and branched stent grafts, as well as 
snorkel and chimney techniques.1,2 However, all 
these technical solutions are relatively complex 
and require appropriate anatomical conditions 
and highly skilled operators since the learning 
curves for the implantation of these devices are 
Radiol Oncol 2024; 58(2): 206-213.
Pintaric K et al. / Multilayer flow modulators in treatment of aortic aneurysms 207
very prolonged.3 As an alternative, multilayer 
flow modulators (MFMs) have been developed. 
These are 3-layer stents designed to laminate the 
flow through the aneurysm so that it gradually 
becomes thrombotic without affecting the flow in 
the branches, simultaneously decreasing the peak 
stress on the aneurysm wall.4 This feature is par-
ticularly important in the aortic arch and thoraco-
abdominal region.
Most studies on MFM in the aorta have relied 
on measurements of aneurysm diameters, which 
is the most practical and time-efficient method. 
However, this approach does not provide com-
prehensive information on gradual thrombosis 
of the aneurysm and morphological changes in 
the aneurysm itself.5–8 Volumetric measurements 
and measurements of the flow volume through 
the aneurysm could provide additional informa-
tion about the behaviour of aneurysms over time 
and, thus, about the efficiency of MFM stents. 
Accordingly, our study aimed to evaluate the safe-
ty and efficacy of MFMs implanted between 2011 
and 2019 in a single centre cohort, using volumet-
ric and flow volume assessments along with diam-
eter measurements.
Patients and methods
This retrospective observational study was ap-
proved by the Republic of Slovenia National 
Medical Ethics Committee (Permit No. 55/05/14) 
and was conducted in accordance with the World 
Medical Association Code of Ethics (Declaration 
of Helsinki). We analyzed a cohort of consecu-
tive patients who underwent endovascular treat-
ment for aortic aneurysms using MFMs (Cardiatis, 
Isnes, Belgium) at the University Clinical Center, 
Ljubljana, between March 2011 and October 2019. 
Our institution started using MFMs in 2011, and 
since then, we have implanted MFMs in 17 pa-
tients with aortic aneurysms.
Only patients unsuitable for open surgical treat-
ment or other endovascular procedures were con-
sidered for endovascular treatment with MFM by 
a multidisciplinary board held for each patient. 
The exclusion criteria were rupture of aortic aneu-
rysm, stenosis of branch arteries (arteries of head 
and neck, visceral and iliac arteries), occlusion of 
the aortoiliac segment, prior endovascular or sur-
gical treatment of the same aneurysm, mycotic 
aneurysm, myeloproliferative blood disorders, 
known coagulopathies, and expected survival less 
than six months.9 For each patient, a consultation 
was held with Cardiatis (Isnes, Belgium) before 
the procedure to obtain their consent for MFM im-
plantation.
Planning of the procedure was primarily per-
formed by experienced interventional radiologists 
using computed tomographic (CT) angiography. 
Critical parameters assessed and measured prior 
to MFM implantation included the status of outgo-
ing arteries (especially eventual stenoses), the larg-
est diameter of the aneurysm, the diameter of the 
healthy vessel above and below the aneurysm, and 
the length of the aneurysm. Diagnostic images were 
shared with the MFM manufacturer and operator, 
who subsequently performed size of device deter-
mination, applying an oversizing of 10−15%. The 
total volume and flow volume of the aneurysms 
were estimated using the OsirX (Pixmeo, Geneve, 
Switzerland). These two parameters were also as-
sessed in the last follow-up CT angiographies. 
All procedures were performed under general 
anesthesia. Prophylactic antibiotics were admin-
istered prior to the procedure, and 5000 IU of 
Heparin was administered during it. Bilateral ac-
cess in the groin was achieved, and a large-bore 
sheath (22−24 Fr) was implanted at the site with 
larger iliac arteries through the common femoral 
artery to accommodate the MFM delivery system. 
The contralateral side was utilized to provide a 
diagnostic catheter, essential for precise MFM 
implantation. The MFM was carefully implanted 
using a slow release and push-pull technique to 
ensure adequate sealing of the affected aortic seg-
ment. In all patients, complete percutaneous hemo-
stasis was successfully achieved using the ProStar 
XL/ProGlide systems (Abbott Laboratories, IL, 
USA). Following the procedure, all patients were 
prescribed lifelong treatment with acetylsalicylic 
acid and a three-month course of clopidogrel. 
Figure 1 shows volume rendering of aorta with im-
planted MFM and fluoroscopy image of implanted 
MFM in thoracoabdominal aorta.
The follow-up period in this study extended 
from the date of MFM implantation to the most 
recent CT angiography available in the hospital 
information system. Patient survival status, as of 
May 2023, was determined based on the cause of 
death listed in the National Registry.
For each patient, the technical success of the 
intervention, procedure-related complications, ad-
herence to usage instructions, and mortality were 
documented. Technical success was defined as the 
accurate deployment of MFM at the targeted sites 
with the absence of any leaks at the attachment sites 
or the junctions of different device components.5
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Pintaric K et al. / Multilayer flow modulators in treatment of aortic aneurysms208
Serious adverse events such as cerebral stroke, 
renal ischemia, paraplegia, and aneurysm rupture 
were recorded. Complications attributed directly 
to the procedure were monitored at one month and 
twelve months after intervention. Furthermore, 
any potential reinterventions were noted, includ-
ing the timing and cause for these additional pro-
cedures.
Additionally, the aneurysm diameters and vol-
umetric data were calculated. Volumetric assess-
ments of the aneurysms (total volume of the aneu-
rysm sac and volume of aneurysm with retained 
flow) were performed prior to the implantation of 
the MFM and repeated in the last available CT an-
giography for each patient. The volumetric meas-
urements were performed by Cardiatis (Isnes, 
Belgium). Incidences of branch occlusions, if any, 
were also reported.
Statistical analysis
Statistical analysis was performed using GraphPad 
Prism 10 (GraphPad Software Inc., San Diego, CA, 
USA). Data are presented as median, interquartile 
range (IQR), range, frequency, and proportion. The 
comparison of numerical variables was performed 
using the Mann-Whitney test. Spearman’s corre-
lations were used to test variable correlations. A 
p-value of 0.05 was considered statistically signifi-
cant.
Results
Demographic data and clinical 
characteristics
During the study period, 17 patients were treat-
ed with MFM for aortic aneurysms, including 16 
males and one female. The median age was 68 
years (IQR: 66−78, range: 48–81 years). Four MFMs 
were implanted in aortic arch, six in thoracic aorta, 
one in thoracoabdominal aorta and two in abdom-
inal aorta. The age of the patients at MFM implan-
tation, the year of the first endovascular treatment, 
and the location of the placed MFM are shown in 
Table 1. All procedures were performed electively. 
The median duration of follow-up was 25 months, 
with an IQR of 13−58 months and an overall range 
of 7−76 months.
Procedure and procedural complications 
The procedure was performed according to the 
manufacturer’s instructions in 70.6% of patients. 
In other patients aneurysm was larger then 6.5 
cm, which is not according to the manufacturer’s 
instruction of use.8 However, all procedures were 
performed with the consent of manufacturer. The 
technical success rate was 100%, and a total of 23 
stents were implanted to treat all 17 patients.
The 30-day procedural complication rate was 
17.6% (3/17). One patient required an additional 
stent graft after a few days to achieve an optimal 
proximal seal, as no additional MFM was available 
during the procedure. One patient was diagnosed 
with a type A dissection at CTA follow-up, which 
was attributed to the procedure itself, while one 
other was diagnosed with a dissection of the ce-
liac trunk. Note, that the aforementioned type A 
dissection was stable on following CTAs, and car-
diovascular surgeouns did not decide for surgi-
cal treatment. Additionally, one patient suffered a 
cerebral infarction due to a pre-existing stenosis of 
the left carotid artery and brachiocephalic trunk 
(however, poor adherence to antiplatelet medica-
tion was noted in this patient). None of the patients 
required open surgery due to these complications, 
and none developed paraplegia, end-organ failure, 
or aneurysm rupture.
FIGURE 1. Volume rendering of implanted multilayer flow modulators (MFMs) (A) 
and fluoroscopic image of implanted MFM (B) in thoracoabdominal aorta.
A B
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Pintaric K et al. / Multilayer flow modulators in treatment of aortic aneurysms 209
Mortality
The intraoperative and 30-day mortality rates 
were both 0%. After 12 months, the aneurysm-
related mortality rate was 5.9% (1 in 17 patients). 
As of May 2023, 5 of the 17 (29.4%) patients were 
still alive, while 12 (71.6%) had died. Three of these 
deaths were due to aneurysm ruptures that oc-
curred 9 months, 40 months, and 51 months after 
MFM implantation. The remaining deaths were at-
tributed to other causes, including head and neck 
cancer, pneumonia, myocardial infarction, and 
suicide.
Aortic branch occlusions
Aortic branch occlusions following the MFM im-
plantation occurred in 5 patients (29.4%) – one pa-
tient developed chronic renal failure due to steno-
sis of the left renal artery (which did not require 
haemodialysis). Vascular occlusion in the other pa-
tients included stenosis of the superior mesenteric 
artery, left subclavian artery, superior mesenteric 
artery and the celiac trunk (with robust collaterals 
from the inferior mesenteric artery), and the left 
carotid artery and the brachiocephalic trunk.
Reinterventions
Reintervention was required in 7 patients (41.2%) 
as shown in Table 2. Most reinterventions were 
performed in the early years of our practice due to 
type 1 leaks.
Changes in aneurysm size after MFM 
implantation
The median aneurysm volume before MFM im-
plantation was 309 ml (IQR: 223−452 ml, range 
32−856 ml) with a median diameter of 58 mm (IQR: 
51−68 mm, range 26−96 mm). At the last follow−up, 
the median aneurysm volume was 355 ml (IQR: 
237−608 ml, range: 62−881 ml), while the median 
diameter was 76 mm (IQR: 57−92 mm, range 27−103 
mm).
Based on volume measurements, five patients 
(29.4%) experienced shrinkage of the aneurysm 
at the last follow-up, two (11.8%) experienced no 
volume change over time, and ten (58.5%) experi-
enced an enlargement of the aneurysm during the 
observation period. In latter patients, the median 
enlargement of the sac was 96 ml (IQR: -15−117 ml, 
range -84−718 ml) in volume and 15 mm (IQR: 3−27 
mm, range: -7−49 mm) in diameter. Nine of these 
patients had an enlargement of the aneurysm for 
more than 10% of the initial volume. 
Per the measurements of the maximum diame-
ter, fifteen patients (88.2%) experienced an increase 
in the diameter of the aneurysm, one patient expe-
rienced shrinkage, and in one patient, the diam-
eter remained stable during the follow-up period. 
Patient-specific measurements are presented in 
Table 3.
There were no significant correlations between 
the aneurysm volume before MFM implantation 
and absolute or relative change in the aneurysm 
volume after MFM implantation (p = 0.9167 and p 
= 0.4473, respectively). We only noted a significant 
positive correlation between the aneurysm vol-
ume before MFM implantation and the aneurysm 
volume at the last follow-up after MFM implanta-
tion (ρ = 0.71, p = 0.0013) and between aneurysm 
volume and maximal diameter ( ρ = 0.86, R2 = 0.74, 
p = 0.0001).
There was a significant positive correlation be-
tween follow-up duration and both absolute and 
relative changes in aneurysm volume and diam-
eter (absolute volume: ρ = 0.62, p = 0.0084, relative 
volume: ρ = 0.70, p = 0.0017, absolute diameter: ρ 
= 0.65, p = 0.0046, relative diameter: ρ = 0.66, p = 
TABLE 1. Age of patients at procedure, year of procedure, and location of 
multilayer flow modulator (MFM)
Patient Age Procedure year Location of MFM
1. 48 2012 Thoracic aorta
2. 79 2012 Thoracic aorta
3. 80 2012 Thoracic aorta
4. 73 2013 Aortic arch
5. 65 2013 Thoracic aorta
6. 67 2016 Aortic arch
7. 68 2016 Thoracic aorta
8. 63 2016 Abdominal aorta
9. 71 2016 Thoracic aorta
10. 80 2017 Abdominal aorta
11. 67 2017 Aortic arch
12. 65 2017 Aortic arch
13. 76 2018 Thoracoabdominal aorta
14. 75 2018 Thoracoabdominal aorta
15. 81 2018 Abdominal aorta
16. 66 2018 Abdominal aorta
17. 66 2019 Thoracoabdominal aorta
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Pintaric K et al. / Multilayer flow modulators in treatment of aortic aneurysms210
0.0040). Therefore, we normalized absolute and 
relative changes in aneurysm size to follow-up 
duration; however, again, there were no signifi-
cant correlations between initial aneurysm size 
and normalized absolute and relative changes in 
aneurysm size after MFM implantation. Moreover, 
there were no significant correlations between ini-
tial aneurysm size or change in aneurysm size and 
patient age. 
Three patients (17.6%) had complete occlusion 
of the aneurysm sac with a thrombus around the 
implanted MFM, twelve patients (70.6%) still had 
partial flow in the aneurysm sac (four of them, 
however, with only minimal presence of contrast 
medium on CT angiography), and two patients 
(11.8%) had a completely non-occluded aneurysm 
sac with flow still present in the aneurysm sac.
Changes in aneurysm flow volume after 
MFM implantation
Six patients had an increase in flow volume 
(35.3%), and 11 patients had a decrease in flow 
volume (64.7%) at the last follow-up, which is con-
sidered a favourable haemodynamic outcome. The 
median volume before MFM implantation was 183 
ml (IQR: 159−262 ml, range: 18−468 ml), and the 
median flow volume at the last follow-up was 168 
ml (IQR: 125−268 ml, range: 6−555 ml). The median 
change in flow volume was -12 ml (IQR: -36−31 
ml, range: -94−124 ml), and the median relative 
decrease in flow volume was 8% (IQR: -19%−15%, 
range: -64%−49%). We found no significant correla-
tion between the patient’s age, duration of follow-
up, or initial size of the aneurysm and the change 
in absolute or relative flow volume. There was also 
no significant correlation between absolute or rela-
tive change in aneurysm volume or diameter and 
absolute or relative flow volume.
Discussion
We studied consecutive patients treated with 
MFM stents for aortic aneurysms between 2011 
and 2019 in our centre. We found that flow vol-
ume decreased in 11 out of 17 patients after MFM 
implantation, which is considered a favourable 
hemodynamic response; however, this did not cor-
relate with a decrease in aneurysm sac size. In 15 
out of 17 patients, the aneurysm sac increased in 
diameter, which was also accompanied by an in-
crease in volume in 10 out of 17 patients. 
Our institution was one of the first centers to 
perform treatment with MFM stents for aortic 
aneurysms. This study, therefore, has one of the 
longest follow-up periods currently published in 
the literature. The literature review by Pinto et al. 
concluded that the implantation of MFMs is safe 
with few complications, although no randomized 
studies were available.9 Most of the studies pub-
lished to date included a few patients, usually less 
than 30, with a relatively short follow-up period 
of no more than 12 months.5–8,10–15 A larger study 
with 103 patients was published by Sultan et al. in 
2014 but with a short median follow-up of only six 
months.15 There are two studies that report a medi-
an follow-up time of 22 months: one from Ireland 
with 14 patients included11 and the other from Italy 
with only 8 patients included.13
The literature mostly reports measurements of 
the aneurysm maximal diameters.5–8,10–15 To our 
knowledge, our study is the first to evaluate volu-
metric measurements before MFM implantation 
TABLE 2. Time and cause of reinterventions after multilayer flow modulator (MFM) implantation
Patient 
number
Time after MFM 
implantation (months) Cause of reintervention; reintervention undertaken
1. 25 Endoleak type I and enlargement of the aneurysm; implantation of another MFM
2. 3 Insufficient proximal seal and collateral flow, resulting in enlargement of the aneurysm; implantation of another MFM
3. 1 Insufficient proximal seal; implantation of another MFM
4. 8 Enlargement of aneurysm and partial stenosis of subclavian artery; implantation of another MFM into previous MFM 
6. 13 Stenosis of brachiocephalic truncus; implantation of a stent, which resulted in a stroke
9. 9 Migration of the MFM; implantation of another MFM
10. 74 Displacement of MFM and stent graft; implantation of another stent graft
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Pintaric K et al. / Multilayer flow modulators in treatment of aortic aneurysms 211
and at the follow-up over a longer period. Two 
studies by Sultan et al., which included patients 
with first-generation MFMs, performed volu-
metric evaluation of aneurysm sacs over several 
months.14,15 The first from 2013 reported an over-
all mean increase in sac volume of 3.3% in 55 pa-
tients14, while the second study with 103 patients 
in 2014 reported an overall mean increase in sac 
volume of 5.1% and a mean volume change of 63 
ml 12 months after implantation.15 In our series, 
the mean volume increase was 33.4% and 91 ml, 
which is significantly more than noted by Sultan et 
al. This could be due to the longer observation pe-
riod in our study, which is also supported by a sig-
nificant positive correlation between the follow-up 
period and the change in volume and diameter of 
the aneurysm sac.
The proportion of aneurysm sac expansion in 
our study is consistent with the findings of Lowe 
et al.11, who conducted a prospective study on pa-
tients treated with MFMs, characterized by a mean 
patient age of 74 years and a follow-up period of 22 
months. Their findings revealed that none of the 
aneurysms demonstrated shrinkage. They report-
ed a one-year all-cause survival rate of 79%, which 
dropped to 50% at two years. Remarkably, only two 
patients exhibited stable aneurysm sac diameters, 
with all others experiencing aneurysm sac volume 
expansion. While their conclusion does not sup-
port the continued use of MFMs, it is important to 
note that their study, conducted from 2011 to 2014, 
included only patients fitted with the first genera-
tion of the device. On the contrary, Vaislic et al. re-
ported a very high proportion of stable aneurysm 
sac size (90%); however, the observational period 
was only 12 months.16
We found a strong correlation between aneu-
rysm sac enlargement and follow-up period, which 
suggests that MFM implantation is probably not 
a lifelong stable solution as often advertised by 
the industry. Most of the aneurysm sacs became 
completely or partially obliterated by thrombus, 
which is consistent with the manufacturer’s cau-
tion. However, despite that, in almost two-thirds 
of patients, the flow volume decreased, and the 
aneurysm sac size increased both in volume and 
diameter. We also noticed a strong positive cor-
relation between aneurysm volume and diameter 
TABLE 3. Aneurysm size before and after multilayer flow modulator (MFM) implantation 
Patient 
number
Aneurysm volume (ml) Aneurysm diameter (mm)
Difference between the last 
follow-up and before the 
MFM implantation Duration of 
follow-up 
(months)Before MFM 
implantation
At last 
follow-
up
Before MFM 
implantation
At last 
follow- 
up
Volume (ml 
[%])
Diameter
(mm [%])
1. 345 854 65 107 509 [147] 42 [64] 76
2. 888 920 122 130 32 [4] 8 [7] 9
3. 309 943 70 110 634 [205] 40 [57] 50
4. 255 355 57 93 100 [39] 36 [63] 69
5. 75 62 26 27 -13 [-17] 1 [4] 14
6. 197 330 44 76 133 [68] 32 [73] 49
7. 343 549 65 85 206 [60] 20 [31] 28
8. 311 266 48 68 -45 [-14] 20 [42] 3
9. 575 667 76 81 92 [16] 5 [7] 14
10. 539 530 97 90 -9 [-2] -7 [-7] 40
11. 32 62 34 50 30 [94] 16 [47] 48
12. 411 411 54 55 0 [0] 1 [2] 33
13. 493 409 53 57 -84 [-17] 4 [8] 24
14. 262 332 60 75 70 [27] 15 [25] 23
15. 307 223 59 81 -84 [-27] 22 [37] 18
16. 130 113 58 58 -17 [-13] 0 [0] 19
17. 250 250 54 60 0 [0] 6 [11] 7
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Pintaric K et al. / Multilayer flow modulators in treatment of aortic aneurysms212
change, suggesting that diameter measurements 
are probably sufficient for assessing aneurysm 
size at follow-up CT angiographies. 
We observed that 41% of patients required re-
intervention, a rate lower than the approximately 
77% reported by Ibrahim et al. in 2018.8 This dis-
crepancy may stem from the urgency of treatments 
in the latter study, where most patients underwent 
emergency procedures. The selection of devices 
and implantation techniques in emergency sce-
narios differs markedly from those in elective 
procedures. Additionally, a notable proportion 
of reinterventions in our series was attributed to 
technical challenges associated with the first-gen-
eration MFMs, suggesting that device technology 
advancements may influence the need for subse-
quent interventions.
Existing literature suggests that aneurysm-re-
lated survival rates 18 months post-implantation 
of MFMs can be as low as 25.6% when these de-
vices are used with deviations from the prescribed 
instructions.15,17 However, our data indicates more 
favourable long-term survival outcomes, despite 
29.4% of the procedures in our study deviating 
from the recommended usage guidelines. A sig-
nificant factor contributing to these improved out-
comes is likely the elective setting in which our 
procedures were conducted, suggesting that the 
context of the procedure may play an important 
role in patient survival post-implantation.
In our study, we observed three deaths attribut-
ed to aneurysm rupture: one occurring 9 months, 
another after 40 months, and the third nearly 6 
years post-MFM implantation. Although the an-
eurysm-related mortality was relatively low, the 
overall mortality rate was notably high. This may 
be partly attributed to the inclusion of patients un-
suitable for surgical intervention, often due to their 
suboptimal general health conditions. Notably, 
the instance of an aneurysm rupture 6 years after 
MFM implantation underscores the importance of 
prolonged follow-up in these patients, highlight-
ing the need for ongoing monitoring even years 
after the initial treatment.
The primary limitation of our study, as with 
many others focusing on MFMs, is the relatively 
small patient sample size. However, our research 
holds distinct value due to its nature as a consecu-
tive series conducted by a consistently trained 
team in a single centre. Furthermore, the extensive 
duration of our follow-up and the employment of 
volumetric measurements offer a significant con-
tribution to the existing body of knowledge in the 
field of intravascular treatments.
Conclusions
MFMs present a viable treatment alternative for 
high-risk patients who are unsuitable for surgery 
and stent grafts. However, long-term real-life data 
show that while MFMs may not be as effective 
in preventing aneurysm expansion as originally 
thought, they can still provide a relatively stable 
haemodynamic solution over a prolonged period. 
Our study found a correlation between the dura-
tion of follow-up and the increase in aneurysm sac 
size. Although there are often no alternative treat-
ment options for these patients and MFM insertion 
generally carries a low risk of periprocedural and 
long-term complications, careful, lifelong follow-
up is essential to recognize early signs of deterio-
ration and intervene appropriately.
Acknowledgments
The authors are thankful to dr. Chiedozie Kenneth 
Ugwoke for manuscript proofreading. This study 
was supported by University Medical Center 
Ljubljana tertiary funding. The author N.U. was 
supported by Slovenian Research and Inovation 
Agency, grant No. P3-0043.
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