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Chapter 143 Mechanical Interventions in Arterial and Venous Thrombosis 2117

TABLE Rutherford Classification of Acute Limb Ischemia
143.2
Clinical Examination Doppler Signal
Category Description/Prognosis Sensory Loss Muscle Weakness Arterial Venous
I. Viable Not immediately threatened None None Audible Audible
II. Threatened
IIa. Marginally Salvageable if promptly treated Minimal (toes) or none None (Often) audible Audible
IIb. Immediately Salvageable with immediate More than toes, associated Mild, Moderate (Usually) audible Audible
revascularization with rest pain
III. Irreversible Major tissue loss or permanent Profound, anesthetic Profound, paralysis Inaudible Inaudible
nerve damage inevitable (rigor)

TABLE Contraindications to Thrombolytic Therapy Mechanical Interventions in Deep Vein Thrombosis
143.3
Venous thromboembolism (VTE) occurs in 350,000–600,000
Absolute Contraindications persons per year in the United States alone, of which more than
Active bleeding 250,000 cases represent a first-episode of deep vein thrombosis
History of stroke within the previous 3 months (DVT). The management of DVT has traditionally been anchored
Neurosurgery (intracranial, spinal) within the previous 3 months in a longstanding view of the disease as an “acute” condition involving
Intracranial trauma within the previous 3 months an initial period of high risk of PE (which is estimated to kill over
Relative Contraindications 100,000 persons in the United States each year), followed by a
Recent (<7–10 days) major surgery, trauma, CPR, obstetrical delivery, steadily diminishing risk over time that ultimately permits discon-
or cataract surgery tinuation of anticoagulant therapy in most patients. In recent years,
Recent (<7–10 days) major invasive procedure or puncture of there is better appreciation of the long-term impact of DVT in terms
uncompressible vessel of the risk of recurrence, particularly in those with unprovoked VTE,
Recent (<3 months) internal eye surgery or hemorrhagic retinopathy and the high incidence of PTS in patients with extensive DVT.
Acute gastroduodenal ulcer or recent (<7–10 days) gastrointestinal Anticoagulation is the mainstay of initial DVT therapy. During
bleeding the last few years, the number of anticoagulant options for DVT
Intracranial neoplasm, arteriovenous malformation, aneurysm, or other therapy has increased substantially. Historically, initial anticoagula-
lesion tion has consisted of administration of a parenteral anticoagulant
Uncontrolled hypertension (systolic >180 mmHg or diastolic drug (unfractionated heparin, low-molecular-weight heparin
>110 mmHg) [LMWH], or fondaparinux) with subsequent transition to long-term
Hepatic failure, particularly in cases with coagulopathy oral vitamin K antagonist therapy for at least 3 months, with the
Bacterial endocarditis or septic thrombophlebitis duration of therapy dependent on the presence or absence of ongoing
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Pregnancy risk factors for recurrence. The preferred initial approach for most
Severe anemia or thrombocytopenia patients with cancer-related DVT has been LMWH monotherapy for
at least 3–6 months. These longstanding treatment options are now
supplemented by the availability of an oral direct thrombin inhibitor
(dabigatran) and three oral direct factor Xa inhibitors (rivaroxaban,
the potential for thrombus fragmentation and embolization, this apixaban, and edoxaban). 19
technique does not appear to be well suited for management of The therapeutic goals of anticoagulant therapy are to prevent
arterial occlusions. 17 symptomatic and fatal PE, thrombus progression, and late recurrent
DVT. All of the currently available anticoagulants are effective in
Summary: Indications and Contraindications for achieving these goals in most patients. In general, during the first year
after discontinuation of anticoagulant therapy, recurrent VTE events
Thrombolytic Therapy in PAO occur in 3%–5% of patients whose DVT episode was provoked by a
major reversible risk factor and in 10%–15% of patients with
The use of arterial CDT should be individualized. Reasonable can- unprovoked/idiopathic DVT or cancer-related DVT.
didates include those with (1) acute (<14 days) thrombosis of a previ-
ously patent bypass graft or native artery; (2) acute embolus in a vessel
not readily accessible to surgical embolectomy; (3) acute thrombosis Rationale, Benefits, and Risks of CDT for DVT:
of a popliteal artery aneurysm resulting in severe ischemia when all
distal run-off vessels are also thrombosed; and (4) acute arterial PTS develops in 20%–50% of patients after a first episode of lower
20
thromboembolic occlusions in patients who are poor surgical candi- extremity DVT. The symptoms and signs of PTS include chronic
dates. The clinical status of PAO patients should be classified using aching, swelling, fatigue, heaviness, edema, hyperpigmentation, and/
the Rutherford scheme (Table 143.2). Patients with Rutherford class or subcutaneous fibrosis in the affected limb. In severe cases, patients
I, class IIa, and in specific cases class IIb disease are potential candi- may experience short-distance venous claudication and venous leg
dates for CDT. Patients with category III ischemia should not be ulcers, both of which limit ambulation and the ability to work and
treated percutaneously because catheter-based thrombolysis often perform the activities of daily living. Consequently PTS reduces
takes many hours and ischemic changes may become irreversible over health-related QOL. In fact, in a recent large prospective cohort
the course of treatment. In patients with irreversible limb ischemia, study, the presence and severity of PTS were the leading determinants
21
mild-to-moderate ischemia with claudication, early postoperative of QOL 2 years after an initial lower extremity DVT. PTS also
bypass graft thrombosis, or large-vessel thrombi that are easily acces- occurs with moderate frequency in patients with upper-extremity
sible by surgery, open surgery is preferred over CDT. Absolute and DVT, particularly those who present with axillosubclavian vein
relative contraindications to CDT are outlined in Table 143.3. involvement in the dominant arm. The management of PTS results