LETTERS
Retrievable Inferior Vena Cava
Filters in High-Risk Trauma Patients
Ronald F Sing,
DO
,
FACS
, Andrew Harrell,
MD
,
Kent W Kercher,
MD
,
FACS
,
B Todd Heniford,
MD
,
FACS
Charlotte, NC
The recent article by Dr William Hoff and colleagues,
1
“Early Experience with Retrievable Inferior Vena Cava
Filters in High-Risk Trauma Patients,” describes inser-
tion and removal of a retrievable vena cava filter in the
trauma population. In this series, filters remained in situ
for an average of 10.2 days after insertion or reposition-
ing (precise overall duration of implantation is not
clear). The authors did not describe guidelines or criteria
for timing of removal. Our concern is that many filters
may have been removed while patients were still “at risk”
for a thromboembolic event. In a similar report by Morris
and colleagues,
2
average duration of implantation was
longer (19 days), and yet Morris and colleagues reported a
postremoval pulmonary embolism. Owings and col-
leagues
3
examined the timing of pulmonary embolism in
their trauma patients over a 5-year period and found that
27% of their pulmonary emboli occurred after 9 days
postinjury, suggesting that one-quarter of the patients in
the Hoff report were still at risk for a pulmonary embo-
lism after their filters had been removed.
Timing of filter removal is a major concern because
there may be accelerated filter use because of the option
of removing the filters. The hypothesis is that filter re-
moval will abrogate risk of caval occlusion from long-
term implantation. We must produce objective data to
determine when vena cava filters can be safely removed;
otherwise, we expose patients to the risks of the proce-
dure without the full benefits.
REFERENCES
1. Hoff WS, Hoey BA, Wainwright GA, et al. Early experience with
retrievable inferior vena cava filters in high-risk trauma patients.
J Am Coll Surg 2004;199:869–874.
2. Morris CS, Rogers FB, Najarian KE, et al. Current trends in vena
cava filtration with the introduction of a retrievable filter at a level
I trauma center. J Trauma 2004;57:32–36.
3. Owings JT, Kraut E, Battistella F, et al. Timing of the occurrence
of pulmonary embolism in trauma patients. Arch Surg
1997;132:862–866.
Reply
William S Hoff,
MD
,
FACS
, Brian A Hoey,
MD
,
Michael D Grossman,
MD
Bethlehem, PA
It is a genuine honor to have our study critiqued by Dr
Sing and his colleagues. This group has distinguished
itself for its aggressive approach to thromboembolic dis-
ease, particularly pulmonary embolism, in trauma pa-
tients. Dr Sing has expressed some legitimate concerns
specific to our results and methodology, which he sup-
ports with pertinent citations from the literature.
Dr Sing highlights our mean duration of filter implan-
tation of 10.2 days. This result applies to the 18 patients
who ultimately had their filters removed. Implantation du-
ration was calculated from the time of initial insertion or
repositioning. Because only 3 patients in this group had
their filter repositioned (at 7, 10, and 14 days from initial
placement), reporting an overall duration of implantation
seems of little clinical consequence. In addition, with regard
to the issue of duration of implantation, comparisons are
drawn between our study and a recent report by Morris and
colleagues.
1
But there are several important differences be-
tween the studies that complicate discussion specific to du-
ration of filter implantation:
1. The study by Morris and colleagues is a retrospective re-
view of patients taken from the trauma registry and an
interventional radiology database (ie, nontrauma patients
were included in the study). Our study was restricted to
trauma patients.
2. Five different filter types were utilized in the Morris study.
We used only Günther Tulip filters. Although no human
studies were available to substantiate the practice during
the time of our study, the accepted practice was to remove
Günther Tulip filters by 14 days. At our institution, dura-
tion of implantation has been extended since publication
of this study.
3. It appears as if approximately one-half of the filters placed
in the Morris study were for prophylactic indications. All
filters placed in our study were prophylactic.
634
© 2005 by the American College of Surgeons ISSN 1072-7515/05/$30.00
Published by Elsevier Inc. doi:10.1016/j.jamcollsurg.2004.12.020