LETTER TO THE EDITOR
In a Spin: A Novel Method for Inferior Vena Cava (IVC) Filter
Detachment Following Snare Entanglement
Received: 8 November 2017 / Accepted: 7 February 2018 / Published online: 15 February 2018
Ó Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe
We wish to share a novel and unreported solution to
disengaging a snare which had become entangled on the
legs of an embedded inferior vena cava (IVC) ﬁlter.
During the attempted retrieval of a temporary Cook
Celect Platinum IVC ﬁlter, the Gu
nther Tulip Retrieval Set
(GTRS) loop snare was inadvertently allowed to pass
beyond the ﬁlter and became entangled on the legs.
Attempts to disengage the snare resulted in cranial migra-
tion of the ﬁlter, eventually to the level of the hepatic IVC,
where the ﬁlter was found to be tilted with suspected hook
embedment. The entangled ﬁlter strut was also embedded
causing entrapment of the loop snare.
Despite a prolonged attempt using adjunctive maneu-
vers, including the introduction of a second loop snare via a
secondary jugular venous access and the inﬂation of a PTA
balloon, we were unable to capture the ﬁlter conventionally
or disengage the loop snare (Fig. 1).
We feared that any further cranial migration of the
device would lead to entry into the right atrium of the heart.
It was accepted by the team that if the GTRS wire could
somehow be detached from the loop snare, the ﬁlter could
be left in situ permanently. The use of endoscopic forceps
to cut and free the loop snare was considered; however, the
grasping strength of the forceps was found to be insufﬁ-
cient to cut the snare when tested on the bench ex vivo.
We contacted the Cook European product manager for
IVC ﬁlters in an attempt to gather further bailout strategies
for the scenario. We were informed that the loop snare
could be fatigued and fractured by rotation of the snare
wire through several (20–30) consecutive clockwise fol-
lowed by a similar number of counterclockwise turns.
After repeating this process approximately 4 times, the
loop snare indeed fractured and remained attached around
the IVC ﬁlter allowing us to safely retract the snare wire
The ﬁlter was left in its suprarenal position and con-
sidered permanent. The position of the ﬁlter was conﬁrmed
on contrast enhanced CT demonstrating the hook of the
ﬁlter to be embedded within the hepatic IVC with entry of a
posterior limb into a hepatic vein (Fig. 3).
Filter migration secondary to guidewire entanglement
has been described in the literature, usually secondary to
the use of a j-tipped guidewire during the placement of a
central venous catheter without ﬂuoroscopic guidance .
In such cases, techniques have been described for safely
releasing the wire including advancing a catheter over the
wire under ﬂuoroscopy, as well as the use of the in situ
loop technique described by Savader et al. .
The entrapment of a loop snare around an embedded
ﬁlter has, to our knowledge, only been reported once. In a
recent retrospective review of 142 IVC ﬁlter retrievals
comparing outcomes between procedures performed in the
IR theater by interventional radiologists or operating room
by vascular surgeons and cardiologists by Makary et al. ,
a single incidence of snare entanglement was encountered
whereby conversion to an emergent open ﬁlter removal
was required by vascular surgical means.
The loop snare of the Cook Gu
nther Tulip Retrieval Set
is constructed from platinum braided ‘Elgiloy,’ an alloy
& An Ngo
Department of Interventional Radiology, Royal Liverpool
and Broadgreen University Hospitals Trust, Prescot Street,
Liverpool L7 8XP, UK
Cardiovasc Intervent Radiol (2018) 41:1136–1138