Affiliations: Tampa, FL
Dr. Rolfe is Assistant Professor of Medicine, Division of Pulmonary, Critical Care, and Occupational Medicine and Dr. Solomon is Professor of Medicine and Director, Division of Pulmonary, Critical Care, and Occupational Medicine, University of South Florida College of Medicine, Tampa, FL.
Correspondence to: Mark W. Rolfe, MD, FCCP, 13000 N. Bruce B. Downs Blvd 111C, Tampa, FL
The article by Girard et al published in this issue
of CHEST (see page 903) is a retrospective review that is
unlikely to be repeated. The data were collected between 1984 and 1988
and presented at an annual meeting in 1990. The data were not submitted
for peer review until nearly a decade later.
The population examined in this study consisted of patients with
angiographically proven pulmonary emboli (PE). No data are presented to
be able to ascertain the results of ventilation/perfusion
(V̇/Q̇) scans that may have proceeded the angiograms.
Patients with a diagnostic pulmonary angiogram then underwent bilateral
lower-extremity venography. Since the treatment for deep venous
thrombosis (DVT) and PE are the same, why do venography at all?
The authors state that it was a practice in France at the time of this
investigation to look for free-floating thrombi (FFT) and, if present,
to place an inferior vena cava filter to prevent potentially lethal
recurrent emboli. Although this practice is debated,1–3
given the frequency of PE due to FFT, it would be reasonable in certain
high-risk patients (those with a large pulmonary clot load plus FFT,
for example). Unfortunately, FFT is not clearly defined by the authors.
Were the clots moving within the vein, or did FFT represent only fresh
clot that had not yet attached to the vessel wall? Is venography
superior to ultrasound in determining this?
Although we do not have V̇/Q̇ scan results or clinical risk
data, we can safely assume that a significant number of these patients
had at least an indeterminate V̇/Q̇ scan. It is also
important to remember that 12 to 26% of patients with even low
probability V̇/Q̇ scans will have positive
angiograms.4–5 Girard et al found positive lower-extremity
venograms in 174 of 213 patients with PE (81.7%). Thirty-nine of the
patients had normal venograms and positive pulmonary angiograms
(18.3%). Only 128 of 174 patients (60%) had DVT; the remaining 46
patients (40%) had calf vein (CVT) thrombosis. Although some may
speculate that in those 46 patients the PE may have originated in the
deep venous system, this study would suggest that the discovery of a
CVT should be considered a marker for possible pulmonary embolic
The lesson from this study comes from the realization that a currently
popular algorithm for evaluating patients with possible PE
(intermediate V̇/Q̇ scans) relies on negative lower-extremity
ultrasound studies to direct further treatment and
evaluation.6In patients with symptomatic lower
extremities, ultrasound has a 97% sensitivity for DVT.7–
In patients with asymptomatic lower extremities, the sensitivity
drops significantly to between 29 to 40%.8–9 In the study
by Girard et al, only 42% of patients who were eventually proven to
have lower-extremity thrombosis had symptoms associated with this
suggesting DVT. Taken together, one would have to question the practice
of dismissing the diagnosis of PE in patients with low to intermediate
V̇/Q̇ scans and asymptomatic lower extremities with negative
The incidence of dye-induced phlebitis is all but negligible with newer
low ionic contrast material. The study by Girard et al demonstrates
that PE is a “systemic disease process with a high incidence of
co-existent pulmonary emboli and lower extremity thrombosis.”
This being said, perhaps our algorithm should suggest that in patients
with low to intermediate probability V̇/Q̇ scans and
asymptomatic lower extremities, the next step should be bilateral
lower-extremity venography and not ultrasound studies. The
lower-extremity venograms would detect clot from the calves,
markers of probable PE, through the deep venous system and into the
iliac system. A positive venogram could then “strengthen” the
probability of the V̇/Q̇ scans, and treatment could proceed
accordingly. Lower-extremity venograms are less invasive than
pulmonary angiography and are probably sufficient in most patients to
preclude further studies.
Unfortunately, years of “perfecting” lower-extremity noninvasive
studies have left many radiology departments unfamiliar with the
techniques and interpretation of lower-extremity venography. The study
by Girard et al reminds us again why gold standards are gold standards,
and it should force us to reassess our reliance on noninvasive studies
of the lower extremities in evaluating patients with possible
Become a CHEST member and receive a FREE subscription as a benefit of membership.
Individuals can purchase this article on ScienceDirect.
Individuals can purchase a subscription to the journal.
Individuals can purchase a subscription to the journal or buy individual articles.
Learn more about membership or Purchase a Full Subscription.
Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 3
Customize your page view by dragging & repositioning the boxes below.
Enter your username and email address. We'll send you a reminder to the email address on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.