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46b. Iliofemoral Deep Venous Thrombosis
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(During Pregnancy)
Anthony J. Comerota
A 24-year-old female who was 32 weeks pregnant presented to the emergency
department at 7 p.m. with a swollen, painful left lower extremity. Her left leg had
become progressively more symptomatic during the past 48 hours. During the
past 24 hours, she began feeling lethargic, had slight shortness of breath, and
began to experience right chest discomfort with deep breathing.
Upon physical examination, her heart rate was 106/min, respiratory rate was
18/min, and blood pressure was 112/70. Her lungs were clear, and her abdomen
was appropriate for her gestational age.
She had a swollen left leg from the foot to the inguinal ligament, which had a
bluish hue. She had pain upon palpation of the left femoral vein. Her arterial
examination was normal.
A venous duplex was ordered and scheduled to be performed in approximately
3 hours.
Question 1
At this point, what would be your next course of action?
A. Obtain an immediate ventilation/perfusion lung scan.
B. Perform a venogram.
C. Start intravenous heparin at 75 mg/kg bolus followed by a continuous infusion
at 15 mg/kg/hour; or, an injection of subcutaneous enoxaparin at 1 mg/kg.
D. Maintain the patient at bed rest until the duplex is completed. If the duplex
confirms deep vein thrombosis (DVT), begin treatment with heparin.
E. Perform an echocardiogram.
The patient had an intravenous line started and a bolus of unfractionated heparin
was given, followed by a continuous infusion. Four hours later, the venous duplex
examination demonstrated venous thrombosis in the posterior tibial vein, popliteal
439
440 Vascular Surgery
vein, femoral vein, proximal great saphenous vein, common femoral vein, and
external iliac vein to the visible limit of the examination. The veins of the right
lower extremity were normal. The patient asks, “What can I expect if treated with
continued anticoagulation?”
Question 2
You tell the patient that she has iliofemoral and infrainguinal deep vein thrombosis,
and that with continued anticoagulation:
A. She will do much better following delivery if she remains anticoagulated for 1 year.
B. She faces a 15–40 percent likelihood of venous claudication at 5 years.
C. She faces a 90 percent likelihood of venous insufficiency and 15 percent like-
lihood of venous ulceration.
D. It is difficult to predict the natural consequences of her disease.
Question 3
This patient’s father has long suffered with post-thrombotic chronic venous
insufficiency, and she expresses a strong desire to avoid post-thrombotic complications. However, she does not want to accept the risks of bleeding associated with
thrombolytic therapy; therefore, she asks for your treatment recommendation.
Your best recommendation to this patient would be:
A. Intravenous heparin for 5 days, followed by oral anticoagulation with a warfarin
compound.
B. Heparin (unfractionated or low-molecular-weight) until the delivery, followed
by warfarin anticoagulation.
C. Rheolytic thrombectomy.
D. Catheter-directed thrombolysis.
E. Operative venous thrombectomy.
Because of her painful lower extremity and her concern for post-thrombotic complications, the patient requested that the thrombus be removed. She was reluctant
to accept the potential bleeding complications of catheter-directed thrombolysis,
and the attending radiologist was reluctant to treat with catheter-directed lysis.
Therefore, venous thrombectomy was planned.
Question 4
The next appropriate step is:
A. Obtain a ventilation/perfusion scan or spiral CT scan of the chest to evaluate for
suspected pulmonary embolism.
Iliofemoral Deep Venous Thrombosis (During Pregnancy) 441
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Fig. 46b.1.
cava. Note fetal skeleton in normal position.
B. Obtain a contralateral iliocavagram prior to taking the patient to the operating
C. Take the patient directly to the operating room and perform the procedure in
D. Anticoagulate overnight and proceed with operative thrombectomy the next
morning a contralateral iliocavagram was performed (Fig 46b.1) prior to taking the
patient to the operating room. A large volume of nonocclusive thrombus was found
throughout the infrarenal vena cava.
A contralateral iliocavagram demonstrates a large volume of nonocclusive thrombus in the vena
room.
order to avoid progressive deterioration.
day.
The patient was anticoagulated with intravenous heparin overnight. The next
Question 5
In light of the findings on the cavagram, what is the best next step?
A. Abandon operative venous thrombectomy and anticoagulate.
B. Perform an AngioJet mechanical thrombectomy of the vena cava and ilio-
femoral venous system.
C. Perform a pulmonary arteriogram to confirm/exclude pulmonary embolism.
D. Obtain an echocardiogram.
E. Insert a suprarenal vena caval filter and proceed with venous thrombectomy
under fluoroscopic guidance.
The patient was presumed to have had a pulmonary embolism. A echocardiogram failed to show right ventricular dysfunction, an enlarged right ventricle, tricuspid insufficiency, or elevated pulmonary artery pressures. Because of the
442 Vascular Surgery
Fig. 46b.2.
potential risk of dislodging nonocclusive thrombus during the venous thrombectomy, a removable suprarenal vena caval filter was inserted (Fig. 46b.2).
X-ray demonstrates suprarenal vena caval filter in proper position.
Question 6
Important considerations during thrombectomy include:
A. Shield the fetus from all X-ray exposure.
B. Perform the venous thrombectomy under fluoroscopic guidance.
C. Monitor the fetus throughout the procedure.
D. Let the nonocclusive thrombus in the vena cava remain undisturbed and
perform a thrombectomy of the iliofemoral venous system only.
Iliofemoral Deep Venous Thrombosis (During Pregnancy) 443
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The patient was taken to the operating room for a venous thrombectomy with
fluoroscopic guidance and fetal monitoring. A cut-down was performed on the left
common femoral and femoral veins, with exposure of the saphenofemoral junction.
A longitudinal venotomy was performed at the level of the saphenofemoral junction, followed by protrusion of a large amount of acute thrombus. The leg was
raised and a tight rubber bandage applied with minimal extrusion of the infrainguinal thrombus. Attempts to pass a catheter from the inguinal ligament distally
into the femoral vein and attempts to pass a guidewire distally were unsuccessful.
Question 7
The next appropriate step would be:
A. Perform iliofemoral and caval thrombectomy with AV fistula, leaving the
infrainguinal thrombus.
B. Abandon thrombectomy and anticoagulate.
C. Perform an infrainguinal venous thrombectomy aided by a cut-down on the left
posterior tibial vein.
A cut-down on the posterior tibial vein was performed. Following a posterior
tibial venotomy, a no. 3 Fogarty catheter was passed upwards through the thrombosed venous system, exiting the common femoral venotomy. This catheter was
used to guide a no. 4 Fogarty catheter distally through the venous valves by placing
both catheter tips within a 14-gauge Silastic intravenous catheter sheath after the
hub was amputated. Following a mechanical balloon catheter thrombectomy, the
leg was flushed using a bulb syringe with a large volume of heparin/saline solution,
which flushed additional thrombus from the common femoral venotomy. After
clamping the femoral vein, the deep venous system was then filled with 300 ml of a
dilute recombinant tissue plasminogen solution (6 mg rt-PA in 300 ml).
The iliofemoral and vena caval thrombectomy was performed under fluoroscopic
guidance, filling the balloon with contrast to ensure that the suprarenal caval filter
was not dislodged. After completing the thrombectomy, an operative iliocavagram
was performed to assess the adequacy of thrombectomy and to ensure unobstructed
venous drainage into the vena cava. An iliac vein stenosis was observed.
Question 8
The appropriate next step is:
A. Close the venotomy and anticoagulate, since a common iliac vein stenosis is fre-
quently observed due to normal vascular anatomy.
B. Close the venotomy and perform an AV fistula.
C. Perform angioplasty and insert a self-expanding stent if recoil occurs.
D. Operatively expose the common iliac vein and perform an endovenectomy and
transpose the vein above the right common iliac artery.
444 Vascular Surgery
a
b
Fig. 46b.3. a
iliac vein. bBalloon dilation corrects the lesion without evidence of recoil, providing unobstructed venous
drainage into the vena cava.
A completion phlebogram following iliofemoral thrombectomy shows stenosis of the left common
Iliofemoral Deep Venous Thrombosis (During Pregnancy) 445
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A balloon angioplasty catheter was placed into the lesion and an angioplasty
performed. The iliac vein was dilated to 14 mm without evidence of recoil
(Fig. 46b.3).
Question 9
Now that patency has been restored to the infrainguinal and iliofemoral venous
systems, are there any additional techniques that can be performed to reduce risk of
rethrombus?
A. An AV fistula, using the end of the proximal saphenous vein sewn to the side of
the superficial femoral artery.
B. The saphenous vein should not be used for AV fistula, since it represents collat-
eral drainage from the leg in the event of recurrent thrombosis.
C. Placement of a catheter into the posterior tibial vein for anticoagulation with
unfractionated heparin.
D. Elevate the legs and avoid ambulation for the next 4–5 days.
E. Therapeutic anticoagulation.
An arteriovenous fistula (AVF) using the proximal saphenous vein anastomosed to the superficial femoral artery increases flow velocity through the
iliofemoral venous system, reducing the risk of rethrombosis. A thrombectomy
of the proximal great saphenous vein was required in this patient, as is often the
case. Since the goal of the AVF is to increase venous blood flow velocity, the size
of the anastomosis is limited to 3.5–4 mm in order to avoid a steal and avoid
venous hypertension. A small piece of PTFE is wrapped around the saphenous
AVF and looped with a 2-cm piece of O-Prolene, which is left in the subcutaneous
tissue (Fig. 46b.4). This will serve as a guide should the AVF require closure.
However, since the AVF is small, it is considered permanent and closure is not
anticipated.
To further reduce the risk of rethrombosis, a heparin infusion catheter (pediatric
feeding tube) is placed into the proximal posterior tibial vein and brought out
through a separate stab wound adjacent to the lower leg incision. Infusing unfractionated heparin through this catheter to achieve a therapeutic PTT ensures a high
concentration of heparin in the target vein, a concentration much higher than
would be achieved if the patient was treated with standard intravenous anticoagulation through an arm vein. A monofilament suture is looped around the catheter in
the posterior tibial vein and brought out through the skin and secured with a sterile
button. This is used to occlude the vein after 5–6 days when the catheter is removed
following full oral anticoagulation with warfarin. In the case of this pregnant
patient, intravenous anticoagulation through the leg veins was maintained for 4
days, after which she was converted to subcutaneous enoxaparin at 1 mg/kg every
12 hours. The catheter was removed and the patient discharged. The patient was
maintained on subcutaneous enoxaparin 1 mg/kg twice a day until she delivered a
healthy baby 6 weeks later.
446 Vascular Surgery
Fig. 46b.4
vein sutured end-side to the superficial femoral artery. Note sleeve of PTFE wrapped around the AVF and looped
with a 2-cm piece of O-monofilament suture. The purpose of this is to assist in operative closure should obliteration of the AVF become necessary.
. The construction of the arteriovenous fistula (AVF) using a large side branch of the great saphenous
Question 10
The patient does not wish to breastfeed her baby. What is your best recommendation for ongoing therapy?
A. Six more weeks of Lovenox.
B. Oral anticoagulation for 6–12 months.
C. Patients’ risk for recurrence is determined by the amount of residual thrombus.
If there is no residual thrombus on venous duplex, additional anticoagulation is
unnecessary.
D. Stop anticoagulation and start aspirin.
Iliofemoral Deep Venous Thrombosis (During Pregnancy) 447
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Question 11
What is your recommendation regarding a thrombophilia evaluation?
A. It is not necessary to perform an expensive thrombophilia evaluation since this
was a DVT of pregnancy.
B. Defer the thrombophilia evaluation until after the patient discontinues anti-
coagulation.
C. Since this patient will be on indefinite anticoagulation, a thrombophilia evalua-
tion is not necessary.
D. Perform tests not affected by anticoagulation and complete the evaluation after
anticoagulation has been discontinued.
An abbreviated thrombophilia evaluation of: lupus anticoagulant, antiphospholipid/anticardiolipin antibody, factor V Leiden, prothrombin gene mutation, and
homocysteine was negative. The remainder of the thrombophilia evaluation will be
completed in 1–2 years, at which time it is anticipated that the patient’s Coumadin
will be discontinued.
Commentary
Although not recognized by the recent ACCP guidelines on antithrombotic therapy
for venous thromboembolism [1], iliofemoral deep venous thrombosis represents a
condition with a uniquely high incidence of post-thrombotic morbidity [2–4].
This patient’s presentation was clinically consistent with iliofemoral deep venous
thrombosis associated with a pulmonary embolism. The adventitia of the femoral
vein is innervated with sensory nerves; therefore, pain on palpation of the femoral
vein as a result of its distension is a frequent physical finding. The femoral vein distends as a result of the associated venous hypertension and thrombosis.
Patients presenting during off hours to the emergency department who are at
high clinical risk of a venous thromboembolic condition should be anticoagulated
[Q1: C] until a definitive diagnosis is made [1].A ventilation/perfusion (V/Q) lung
scan is not performed in this patient because she is pregnant and the clinical probability of a pulmonary embolism is high. The likelihood of the venous duplex
demonstrating acute DVT is also high; therefore, this patient’s treatment is unlikely
to be altered by the V/Q scan findings. There is also reluctance to expose the pregnant patient to a radioisotope. Standard ascending phlebography is not necessary,
since the clinical presentation and venous duplex will establish the diagnosis with a
high degree of accuracy. Once anticoagulation is established, it is not necessary and
actually counterproductive to maintain the patient at bed rest [5]. An echocardiogram is advisable in all patients who have the diagnosis of pulmonary embolism to
evaluate its impact on right ventricular function; however, it is not necessary in this
patient to perform an “off hours” echocardiogram since the patient can be adequately treated until the next business day.
This patient’s thrombus extends from the posterior tibial vein to the external iliac
vein, as documented on venous duplex. The natural history of these patients is one
448 Vascular Surgery
of significant post-thrombotic morbidity. [Q2: B, C] Akesson and colleagues [3]
demonstrated that within 5 years of anticoagulation for iliofemoral deep venous
thrombosis, 95 percent of patients had documented venous insufficiency, 15 percent
had venous ulceration, and 15 percent suffered with venous claudication. Delis et al.
[4] studied in greater detail a similar but larger cohort of patients with iliofemoral
deep venous thrombosis and performed exercise testing. They demonstrated that 40
percent developed symptoms of venous claudication. While pregnancy is an
induced hypercoagulable state, delivery of the present patient’s child is not known
to alter the natural history of the patient’s acute venous thrombosis.
In order to reduce the high risk of post-thrombotic sequelae, a strategy of thrombus removal should be considered. Operative venous thrombectomy [Q3: E] is the
best recommendation in light of the fact that the patient does not wish to face the
additional risk of bleeding with thrombolytic therapy, and the radiologist is reluctant to treat the patient with catheter-directed thrombolysis. Rheolytic thrombectomy is in its early stages, and to date has not been shown to be effective by itself in
the absence of incorporating a plasminogen activator [6]. Oral anticoagulation
during pregnancy is not recommended. Although this patient is in her third
trimester and warfarin embryotrophy is not a concern, the potential coagulopathy
of the fetus due to its immature liver and potential fetal bleeding complications
during delivery as a result of passage through the birth canal make oral anticoagulation inadvisable. Heparin anticoagulation until delivery followed by oral anticoagulation is commonly offered to these patients; however, their post-thrombotic
morbidity is exceptionally high.
A decision was made to proceed with venous thrombectomy. Patients can be anticoagulated overnight and the operation performed the next business day. Venous
thrombectomy does not need to be performed as an “emergency operation.” [Q4: B,
D] In all patients in whom a venous thrombectomy is performed, it is important to
know the proximal extent of thrombus, particularly whether there is thrombus in
the inferior vena cava. Therefore, a contralateral iliocavagram is performed prior to
the iliofemoral venous thrombectomy. As mentioned earlier, it is assumed that this
patient has had a pulmonary embolism and the radiation exposure of a CT scan or a
V/Q scan is unnecessary, since their results are unlikely to change this patient’s
management. However, in the non-pregnant patient, a spiral CT scan of the chest,
abdomen, and pelvis would be performed. The rationale for CT scanning is that
approximately 50 percent of patients with proximal DVT will have an asymptomatic
pulmonary embolism. Up to 25 percent of these patients will develop subsequent
pulmonary symptoms [7]. When the symptoms surface during anticoagulation, the
symptoms are often misinterpreted as “failure” of anticoagulation, when in reality it
is the natural evolution of the patient’s initially asymptomatic (undiagnosed) pulmonary embolism. The proximal extent of thrombus in the vena cava or iliac veins
often can be identified, as well as screening for associated intra-abdominal,
retroperitoneal, or pelvic pathology.
The patient was treated with anticoagulation overnight. Before going to the operating room a contralateral iliocavagram was performed. Information regarding the
proximal extent of thrombus is particularly important, since the details of thrombus
extension may alter the procedure. Nonocclusive thrombus in the vena cava is concerning because of its potential for fragmentation and embolization. This author
believes that these patients should be protected against potential embolization
during the procedure. This can be accomplished either with a suprarenal vena caval
filter, as was inserted in this patient, since it was presumed that she already had suf-
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