Subclavian Vein Thrombosis Treatment & Management

The initial treatment of subclavian vein thrombosis is conservative management, which includes rest, elevation of the limb, and application of heat or warm compresses.

In a few patients who have minimal symptoms and no anatomical defects, physical therapy is always the first goal of therapy. Structured physical therapy may help the patient lose weight and loosens the adhesions at the site of obstruction. Physical therapy may also improve range of motion, decrease swelling, and help decrease pain.

The different natural histories of Paget-von Schrötter syndrome and catheter-induced subclavian vein thrombosis indicate different treatment protocols. Because large series of patients with this condition are lacking, the therapeutic approach to subclavian vein thrombosis is mainly anecdotal.

Heparin

Unfractionated or low molecular weight heparin (LMWH) can maintain patency of the venous collaterals and reduce the chance of propagation of the thrombus. In all cases, heparin therapy is followed by warfarin therapy, with an international normalized ratio (INR) goal of 2-3.

Heparin is usually the initial therapy, followed by warfarin. LMWH has been used for both inpatient and outpatient therapy. Most studies have shown that LMWH is just as effective as unfractionated heparin, but the former is associated with a significant decreased incidence of venous thromboembolism.

Warfarin is continued for 6-9 months, and an INR of 2:3 is maintained. Patients who only receive inpatient heparin and are no longer on warfarin therapy are at risk of recurrence and long-term disability. Anticoagulation is required in all patients for a period of 6-9 months or longer, depending on the cause of the thoracic outlet syndrome. In some patients who also have hypercoagulable disorders, the treatment is lifelong.

Paget-von Schrötter syndrome

Currently, most investigators favor using thrombolytic therapy to rapidly restore patency of the vein. Thrombolytic therapy should be initiated within 5-7 days of venous thrombosis. Fortunately, this syndrome occurs in fairly young individuals who do not have multiple medical illnesses that may contraindicate thrombolytic therapy. Thrombolytic therapy is preferred over thrombectomy because it does not carry the risks of an operation and the possibility of an intimal tear related to the embolectomy catheter.

In some cases, therapy may involve diagnostic venography, followed by thrombolysis, followed by several weeks of anticoagulation. If symptoms recur, a repeat venography may be indicated, possibly followed by balloon dilatation with or without stenting of the subclavian vein, and more anticoagulation. The desired International Normalized Ratio is 2-3. The goal of therapy is to minimize the likelihood of significant symptoms of venous obstruction.

To perform catheter-directed thrombolysis, the catheter is embedded in the thrombus. Urokinase infusion is started with a loading dose of 250,000 IU, followed by 4000 IU for the first hour, and 1000 IU for the next 24 hours. Heparin is infused at a rate of 800 IU/h. Monitoring is performed by maintaining the fibrinogen level at least 80-100 mg/dL. If venous patency is assured, warfarin is maintained for 3-6 months. Recently, urokinase was indefinitely removed from the market, forcing interventional radiologists to adopt less clinically defined protocols using tissue-plasminogen activator (tPA). As the clinical situation with thrombolytic agents evolves and newer agents enter the market, flexibility in thrombolytic administration protocols will be paramount.

Catheter-associated subclavian vein thrombosis

Prophylaxis treatment in patients undergoing chemotherapy may include giving a fixed dose 1 mg of warfarin sodium (Coumadin) daily beginning on day 3 before catheter placement. This has been shown to lower the incidence of thrombosis. Exercise caution in selecting patients for thrombolytic therapy because patients with catheter-associated subclavian thrombosis often have significant comorbidity.

Indications for surgical treatment include (1) the presence of an anatomic anomaly such as anomalous subclavius or anterior scalene muscle, congenital fibromuscular bands, or narrowing of the costoclavicular space from depression of the shoulder; (2) rethrombosis of the vein after previous thrombolytic treatment; and (3) endoluminal stent placement to prevent stent fracture from compression against the first rib.

Forms of surgical treatment can include (1) embolectomy, (2) bypass, (3) first rib resection via the axilla or supraclavicular approach, and (4) medial subtotal claviculectomy.

Endovascular treatment

With recent advances in endovascular therapy, angioplasty and stenting is an excellent way to maintain venous patency. Data and follow-up on this technique are limited. When the superior vena cava is also involved, current endovascular techniques allow for stenting of the vessel, which produces excellent results.

Suction thrombectomy with an AngioJet System (Possis Medical, Inc., Minneapolis, Minn) is often used with thrombolysis when the thrombus is localized. The procedure can rapidly extract the thrombus and reduce both the dose and duration of thrombolytic therapy. Suction thrombectomy is most useful for patients who present early. Surgical thrombectomy is fast becoming the procedure of choice; it is a better alternative to simple anticoagulation.

The purpose of the preoperative evaluation is to determine if known or unsuspected coexisting disease should delay, modify, or preclude the operation. Obtain a history and physical examination to identify risk factors and warning signs of coexisting diseases. This information guides further direction and depth of study.

Relevant laboratory tests include CBC count, serum electrolyte levels, urinalysis, chest radiograph, ECG, clotting profile, crossmatch, and a stool examination for blood.

Consultations should include a general internal medicine physician and an anesthesiologist.

Approach a first rib resection by the transaxillary route^[6] or the supraclavicular route. Typically, the transaxillary route is simpler, safer, and offers cosmetic benefits. The procedure is indicated below.

Using the lateral thoracotomy position with the arm elevated, a skin incision is made in the axillary hairline between the pectoralis major and latissimus dorsi muscles. The first rib is reached by blunt dissection in the axillary tunnel, taking care to avoid the second intercostobrachial nerve.

The subclavian artery and vein are identified, and the subclavius muscle tendon is divided. Then, the anterior scalene muscle is identified and divided at the point where it inserts onto the first rib, anterior to the artery.

At this point, digitally search for anomalous bands. They may originate from the C-7 transverse process, from an incomplete cervical rib, or from the middle scalene muscle.

After any bands are divided, the middle scalene muscle and the intercostal muscle attachments are pushed off the first rib. When all the muscle fibers are cleared and the T-1 nerve root is visualized and protected, the rib is divided and removed.

The wound is irrigated with saline to detect pneumothorax. If present, it can be treated by inserting a small chest tube into the pleural space. The tube can be removed in the recovery room if the lung is fully expanded and no air leak is present.

Pain relief is one of the most important aspects of postoperative care. Various forms of narcotics can be administered parenterally or by patient-controlled analgesia devices. Adequate pain control cannot be over emphasized.

Vital signs should be closely monitored as per unit protocol, then every 4 hours for 24 hours, and then every shift. In most cases, a Foley catheter is not required. Administer 5% dextrose in lactated Ringer solution at 125 mL/h, and keep the arm elevated.

If the surgery is not complicated, routine postoperative laboratory tests are not required. Prothrombin time and activated partial thromboplastin time should be measured every 6 hours if heparin therapy is started.

Early mobilization is important, and discharge planning should begin at admission. Patients usually are discharged when they are medically stable, afebrile, tolerant of oral intake, ambulatory, and reasonably comfortable with the ongoing rehabilitation exercises.

Follow up carefully with patients with subclavian vein thrombosis to ensure that the condition does not reoccur. Patients with persistent symptoms and evidence of recurrence may require radiological workup and, possibly, surgery.

For excellent patient education resources, visit eMedicine's Circulatory Problems Center. Also, see eMedicine's patient education article Phlebitis.

Pulmonary embolism may occur in as many as 20-36% of patients. Stroke may occur as a manifestation of paradoxical embolism in the presence of a patent foramen ovale.

Other complications can include the following:

• Chronic venous insufficiency
• Phlegmasia cerulea dolens
• Superior vena cava syndrome
• Pulmonary hypertension
• Right-sided heart failure
• Thoracic duct obstruction
• Chylous pleural or pericardial effusion
• Brachial plexopathy

Case fatality rates for untreated ASDVT-related pulmonary embolism may be as high as 10%, which is similar to pulmonary embolism originating from the lower extremity. The long-term consequences of venous occlusion cause substantial morbidity related to persistent pain and swelling for protracted periods of time. These symptoms occasionally are severe and can be exacerbated by physical activity, particularly with extended use of the affected arm. Consequently, this syndrome can lead to occupational disability and can adversely impact the patient's quality of life.

Conservative treatment consisting of bed rest, limb elevation, and anticoagulation is associated with a worse outcome. Recent reports suggest that as many as 74% of patients treated with these conservative measures have residual disability compared to those that are treated with thrombolysis.

Subclavian vein thrombosis is becoming a more common problem because of widespread use of central venous catheters for various medical conditions. The demand for a more standardized treatment is becoming greater than ever. However, until randomized data from well-designed trials are available, absolute statements about treatments cannot be made. However, linked medical records using administrative health care data sets may provide information (ie, re-admission or level of outpatient services) on the results of treatment of large numbers of patients with subclavian vein thrombosis or significant risk factors such as central venous cannulation. Until such information is obtained, the best treatment of subclavian vein thrombosis is to prevent it by limiting the use of central venous catheters for extended periods of time.