Page 2377 - Hematology_ Basic Principles and Practice ( PDFDrive )

Chapter 143 Mechanical Interventions in Arterial and Venous Thrombosis 2119

shown that organized thrombus is not susceptible to thrombolytic extensive proximal lower extremity DVT, such as those with acute
drugs). 22 iliofemoral DVT, who have a low risk of bleeding and a long life-
The most important safety factor to consider in a patient being expectancy. 1,25–27 However, the 2016 guidelines update from the
evaluated for DVT thrombolysis is the risk of major bleeding. Factors American College of Chest Physicians recommends against the
associated with an increased risk of bleeding include ongoing or routine use of CDT, with the caveat that patients who attach a high
recent bleeding; recent major surgery, trauma, pregnancy, obstetrical value to PTS prevention relative to bleeding risks and procedural
delivery, or cardiopulmonary resuscitation; or the presence of lesions inconvenience may choose CDT. 18
in critical areas such as the central nervous system, which may bleed.
Because CDT involves the administration of iodinated contrast mate-
rial for venography, renal function is also an important consideration Treatment of Established PTS
as are life expectancy, baseline ambulatory capacity, and comorbidi-
ties. 1,25 Patients with limited long-term mobility or those with a life Patients with established PTS suffer major symptoms that signifi-
expectancy of less than 6 months are unlikely to benefit from aggres- cantly impair their ability to conduct their daily activities and to
sive therapy to prevent PTS. Comorbidities that increase procedure enjoy a normal QOL. Unfortunately once PTS has developed, there
risks, such as respiratory compromise that limits the use of sedation, are no treatments that have consistently been shown to be effective.
may also render CDT less attractive. Despite limited evidence of benefit, elastic compression stockings are
Urgent endovascular thrombolysis is indicated to prevent life-, often utilized because of their low risk and ready availability. Low-
limb-, or organ-threatening complications of acute DVT in situations dose diuretics may be useful to reduce edema. Patients with venous
such as phlegmasia cerulea dolens or extensive IVC thrombosis ulcers can be given pentoxifylline, dedicated wound care with topical
(especially with suprarenal extension, which may lead to fatal PE or antibiotics, exfoliants, and growth factors, and multilayer compres-
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acute renal failure). The use of endovascular thrombolysis in these sion bandaging. Despite these measures, PTS symptoms and venous
situations is justifiable when other treatment options are lacking. In ulcers often resist improvement and cause long-term hardships.
contrast, there is significant uncertainty regarding the appropriate Because the severity of PTS symptoms often parallels the degree
indications for nonurgent CDT for the treatment of DVT. At present, of ambulatory venous hypertension, endovascular interventions that
guidelines of the American Heart Association (2011), Society of eliminate venous obstruction and valvular reflux have been used for
Interventional Radiology (2014), American Venous Forum and treatment of patients with severe PTS. Studies suggest that stent
Society for Vascular Surgery (2012), and the United Kingdom’s recanalization of chronically occluded iliac veins in patients with
National Institute of Clinical Excellence (2012) suggest the use of advanced PTS can be achieved in over 80% of patients and can
CDT/PCDT as an adjunct to anticoagulant therapy for carefully reduce PTS symptoms, improve QOL, and enhance healing of
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selected patients with major symptomatic axillosubclavian DVT or venous ulcers (Fig. 143.3). Accordingly, physicians who see patients

A B
Fig. 143.3 A 46-YEAR-OLD WOMAN WITH A PAST HISTORY OF RIGHT ILIOFEMORAL DEEP
VEIN THROMBOSIS (DVT) 2 YEARS AGO. She now presents to the clinic complaining of daily aching
and swelling in the right lower extremity that preclude ambulation for even one block and render her unable
to work. These symptoms have been present since her previous DVT. (A) A transjugular pelvic venogram
demonstrates chronic narrowing of the right iliac vein with collateral formation. (B) After placement of four
12-mm stents, the right iliac vein is widely patent. The pain and swelling improved, and the patient was
subsequently able to return to work.