Superior Vena Cava Occlusive Disease



Superior Vena Cava Occlusive Disease


Robert F. Dondelinger and John A. Kaufman


Chronic upper extremity (UE) occlusive disease and superior vena cava (SVC) syndrome can be debilitating to the patient and rewarding to treat with endovascular techniques.1 Chronic UE venous occlusion is more often due to a benign lesion, whereas SVC syndrome is more likely the result of malignant obstruction. The symptoms of chronic UE venous occlusive disease include arm swelling (especially with use or after creation of UE surgical dialysis access.2 Although the ipsilateral neck may be symptomatic, facial swelling does not occur with obstruction limited to the UE veins. Acute SVC syndrome is considered a medical emergency.3 Clinical symptoms include headache exacerbated by changes in position, disturbances in consciousness, facial edema, pain in the face and neck, blurred vision, retroorbital pressure, hoarseness, and orthopnea. Edema and pain can involve one or both arms. In patients with slowly progressive obstruction, collateral circulation develops to a variable degree over the chest wall and periscapular region. Acute SVC syndrome may be the first sign of a mediastinal tumor or may be seen later in the course of the disease.1 Interventional radiologists were early pioneers in the management of these challenging clinical entities.4,5




Benign Obstruction


Approximately 10% of all clinically significant SVC stenoses are due to a benign cause. The main causes of benign stenosis are catheter-related injury, mediastinal fibrosis, surgery, postanastomotic stenoses, infection, and radiotherapy.2–3 Conversely, most chronic stenoses or occlusion in the central arm veins are benign in nature and due to venous catheterization, instrumentation, and anatomic compression syndromes.




Contraindications


In malignant disease, contraindications to venous stenting include extensive chronic venous thrombosis, anatomic considerations predisposing to severe technical difficulty, and advanced disease in preterminal patients. As a rule, venous access sites should be preserved, and the ostia of large tributaries of the caval system, such as the jugular veins, should not be deliberately covered by a stent to preserve the possibility of further catheterization if necessary. However, the ostium of the azygos vein is routinely covered when stenting the SVC, generally without clinical side effects. Impaired venous flow, such as secondary to limb paralysis, is a relative contraindication to stent placement in the SVC tributaries. Occasionally, transmural venous tumor invasion caused by lymphoma or bronchogenic carcinoma is present. Because uncovered stents may be ineffective in such cases, placement of covered stents is indicated in these infrequent cases.


Patients should be able to cooperate during the procedure. Some patients with severe SVC syndrome may have difficulty lying flat. In these circumstances, the procedure should be undertaken with the patient under general anesthesia. A minority of patients will have simultaneous tracheobronchial narrowing because of malignant compression. Stenting of the airways should precede management of the caval obstruction in such patients.




Technique


Anatomy and Approach


With regard to the venous anatomy of the upper extremities, brachiocephalic vessels, and SVC, please refer to Chapters 30 and 82.


Stenoses located in the SVC or right innominate vein are most conveniently stented via a right femoral or right jugular approach (Fig. 99-1). Stenoses of the left innominate vein are treated from either a femoral or a left axillary approach. By using a rather unconventional puncture site for catheterization of the axillary vein—namely, at the junction between the axillary and subclavian veins—trauma to the brachial nervous plexus is avoided, particularly when large-diameter catheters are introduced. More direct access to the left innominate vein is also gained with use of this technique. As a general rule, venous stents should be placed sequentially, first in a distal position and then more proximally, in relation to the puncture site. When the confluence of the innominate veins is treated, the technique used depends on the anatomy and type of stents required. Soft and flexible stents can be placed simultaneously in the brachiocephalic vein and left innominate vein, with a parallel course in the SVC (Figs. 99-2 and 99-3). When more rigid stents are used, the SVC and right innominate vein are stented in a line, and stents are placed in the left innominate vein as close as possible to the caval axis. Transesophageal ultrasound can occasionally be helpful in accurate stent placement in the SVC, but it makes an otherwise simple procedure much more complicated.7,8


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FIGURE 99-1 Superior vena cava (SVC) syndrome in a 55-year-old man. A, Contrast-enhanced computed tomography shows large mediastinal mass compressing SVC. Left innominate vein was completely thrombosed. B, Superior vena cavography obtained from a right femoral approach confirms tight SVC stenosis. C, A Wallstent (10 mm, 7 cm) was placed via femoral approach and expanded immediately. Cavography shows optimal venous flow. Left innominate vein was not treated. Rapid regression of clinical symptoms followed.

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FIGURE 99-2 This 53-year-old woman with breast cancer was evaluated for severe swelling of both arms. A, Bilateral phlebography of both upper limbs shows tight stenosis of distal portion of both innominate veins caused by central venous infusion catheters for chemotherapy. Note multiple collateral mediastinal and parietal vein filling. B-C, High-pressure balloon dilation was necessary to overcome tight fibrous stenoses. D, Two Wallstents were placed in both innominate veins and protruded into superior vena cava. Cavography shows optimal draining flow.

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FIGURE 99-3 Superior vena cava (SVC) syndrome in a 66-year-old man known to have mediastinal small cell lung cancer. A, Superior vena cavography shows complete obstruction of both innominate veins by mediastinal tumor encasement, a rich venous network, and filling of azygos system (asterisk). B, Local infusion of the thrombolytic agent urokinase was started at a rate of 100,000 units/h in both innominate veins. Phlebography obtained 12 hours later shows complete clearing of clots from both innominate veins and unmasked two tight stenoses (arrows) at their junction with SVC. C-F, Two Wallstents (10 mm, 6 cm) were placed in both innominate veins and protruded into SVC. Balloon dilation inside stents accelerated immediate stent dilation. G, Bilateral phlebocavography confirms patency of both stents and optimal venous flow.


Technical Aspects


Radiographic Technique


Duplex color ultrasound demonstrates stenosis or thrombosis of venous segments accessible to the probe. Loss of cardiac and respiratory variation in the internal jugular veins is suspicious for central obstruction. In most cases, venous-phase helical contrast-enhanced computed tomography (CT) with multiplanar reformatting or magnetic resonance (MR) venography can establish an unequivocal diagnosis of central venous stenosis or obstruction.9 Both modalities demonstrate the location and extent of disease and also show the collateral network. However, venographic demonstration of the stenosis and collateral pathways remains mandatory immediately before treatment. Venography confirms the location and extent of the stenosis, endoluminal thrombus, or tumor proliferation; the extent of collateral circulation; its hemodynamic significance; and any congenital variants that have to be taken into consideration when planning stent placement. Superior venacavography can be performed by simultaneous bilateral injection of contrast into the basilic or a more peripheral vein in the upper limb or jugular veins.


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Dec 23, 2015 | Posted by in INTERVENTIONAL RADIOLOGY | Comments Off on Superior Vena Cava Occlusive Disease

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