Knitted Dacron grafts are easy to handle, soft,
and pliable; however, they tend to dilate due to
their high porosity. Knox[
3] first reported structural
deficiencies in prosthetic grafts in 1962. Bleeding or
pseudoaneurysm formation at the anastomosis site is
a common complication of Dacron grafts in vascular surgery. However, nonanastomotic bleeding connected
to the degeneration of the textile structure of the graft
and the formation of such a giant pseudoaneurysm
starting from the femoral artery and continuing to the
PA is rare in the literature.[
4] The early detection of a
Dacron rupture is tricky due to the unpredictability
of the time between the clinical manifestation. In our
case, we believe the diagnosis was delayed for this
reason.
Manufacturing flaws, such as excessive heating
during yarn texturization, crimping by thermal
fixation, excessive stretching of yarns during knitting,
chemical cleaning, and gamma or beta ray sterilization
are possible causes for the loss of structural integrity of a graft.[2,5] Generally, the graft fabrication process
is standardized, computer-controlled, and extensive
quality control measures are performed before the
graft is marketed.[2] Intrinsic structural graft failure
formations have been reported anywhere from
12 months to 19 years, with an estimated incidence of
0.5 to 3% in the earliest series (Figure 3).[1]
Some studies have reported giant cell reactions
to fragmented Dacron fibers in the histological
examination of the excised graft; however, they have
not demonstrated an effective etiology or a predisposing
factor.[1] In the histopathological examination, lymphocytic inflammatory infiltration was the only
pathological finding involving inflammatory cells.
Figure 3: The degenerated Dacron graft with continued
distal flow through the pseudoaneurysm capsule.
Graft infections in vascular surgery have the
most severe complications, including anastomotic
bleeding, sepsis, and death. The overall incidence
of vascular graft infections is 1.5 to 2% in femoral
grafts.[6] In our case, no infection was detected in
both tissue and graft material.
In the present case, the late degeneration of the
knitted Dacron fibers may have caused gradual
stretching and focal disruption of the graft, resulting in a localized pseudoaneurysm that would subsequently
enlarge.[7,8] Degradation may be related to many
factors, such as designing the textile structure,
fabrication flaws, modifications of the prosthesis
during the manufacturing process or the surgery by
inappropriate handling, unpadded clamps, or the
surgeon's overstretching of the graft. There may
have also been secondary physicochemical alterations
due to chronic foreign body giant cell inflammatory
reactions and mechanical fatigue caused by repeated
bending and the constant systolic-diastolic arterial
stresses.[4,9] Repetitive hydrodynamic microtraumas, as
with pulsatile blood flow, cause progressive stretching
and thinning of the yarn filaments due to cracking or
gradual ruptures. The ends of these distorted, broken
fibers appear tapered and frayed. Once this occurs,
the load is transferred to the remaining neighboring
filaments of the weave, resulting in torn fibers.[2]
During the operation of this patient, we observed that
the graft degenerated along its length, as if supporting
the structural collapse.
Traditionally, aneurysms are treated by the
excision of the disrupted graft and replacement with
a new prosthetic graft.[7,8,10] In our case, we preferred
an open surgical intervention for our patient's
exploratory diagnosis and treatment.
This case study was not extensive. Graft
degeneration should still be considered a late-term
complication despite all the developments in the
construction and inspection processes of Dacron
grafts. No matter how much time has passed since the operation, complications related to grafts should be
kept in mind.
In conclusion, the ideal vascular prosthetic
conduit should be easily accessible, resistant to
dilatation and infections, stable, biocompatible,
and longstanding, with a durability superior to the
patient's life expectancy. They should also provide
and sustain a thromboresistant flow surface and
have elastic properties that ensure a normal artery's
patency, compliance, and flexibility.
Patient Consent for Publication: Written informed
consent was obtained from both the patient and a legally
authorized representative of the patient for their anonymized
information published in this article.
Data Sharing Statement: The data that support the
findings of this study are available from the corresponding
author upon reasonable request.
Author Contributions: Idea/concept: M.K.; Design, data
collection and/or processing, literature review, writing the
article: A.D.; control/supervision, critical review: A.A.
Conflict of Interest: The authors declared no conflicts
of interest with respect to the authorship and/or publication
of this article.
Funding: The authors received no financial support for
the research and/or authorship of this article.
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