Superior Vena Cava Syndrome in Emergency Medicine

Superior vena cava syndrome (SVCS) is characterized by gradual, insidious compression/obstruction of the superior vena cava. Although the syndrome can be life threatening, its presentation is often associated with a gradual increase in symptomatology. For this reason, diagnosis is often delayed until significant compression of the superior vena cava has occurred.

Extrinsic compression of the superior vena cava is possible because it has a thin wall coupled with a low intravascular pressure. Because the superior vena cava is surrounded by rigid structures, it is relatively easy to compress. The low intravascular pressure also allows for the possibility of thrombus formation, such as catheter-induced thrombus.

The subsequent obstruction to flow causes an increased venous pressure, which results in interstitial edema and retrograde collateral flow.

The most common etiology of superior vena cava syndrome is malignancy.[1]

Prior to modern antibiotics, infectious causes including syphilis, tuberculosis, and fungus occurred with almost equal frequency.

The most common cause of malignancy-related superior vena cava syndrome is bronchogenic carcinoma, which accounts for nearly 80% of cases.

Lymphoma accounts for approximately 15% of cases.

Other cases have various causes, including infectious and catheter-related etiologies. Increasingly, dialysis catheters[2] and pacemaker leads[3] are becoming associated with superior vena cava syndrome due to thrombosis.

United States data

Superior vena cava syndrome is chiefly associated with malignancy. Currently, 80-90% of patients with superior vena cava syndrome have an associated malignancy as the cause.[4, 5] This contrasts with studies in the early 1950s in which a large proportion of cases were nonmalignant. Infectious causes (eg, syphilis, tuberculosis) have decreased because of improvements in antibiotic therapy. Of the nonmalignant causes of superior vena cava syndrome, thrombosis from central venous instrumentation (catheter, pacemaker, guidewire) is an increasingly common event, especially as these procedures become more common.

International data

In developing countries, nonmalignant causes of superior vena cava syndrome continue to constitute a significant percentage. Still, superior vena cava syndrome occurs infrequently in the general population.

Race- and age-related demographics

Superior vena cava syndrome has no racial predilection. However, because of poorer access to adequate health care, some socioeconomic groups have a disproportionately greater representation.

Because most superior vena cava syndromes are caused by bronchogenic carcinoma, the age distribution is skewed strongly toward elderly persons. Nonmalignant causes, as well as lymphoma, tend to affect younger people more than malignancy-associated superior vena cava syndrome. The age range reported in one study was 18-76 years, with a mean age of 54 years.[6]

Superior vena cava syndrome (SVCS) is associated with malignancy. The prognosis for relief of superior vena cava syndrome symptoms is good with radiation therapy. Symptoms usually decrease within 1 month of the onset of radiation therapy. However, the ultimate prognosis is associated with the underlying malignancy itself.

The prognosis for superior vena cava syndrome not associated with malignancy is excellent because most of these causes are infectious and respond to appropriate antibiotic therapy.

Recently, management of superior vena cava syndrome by internal jugular to femoral vein bypass has been described.[7] This may help improve symptoms of patients with malignancy.

Morbidity/mortality

Malignant mediastinal tumor accounts for more than 80% of cases of superior vena cava syndrome.[4] Even when treated with radiation, only 10% of these patients are alive 30 months after presentation. However, patients with superior vena cava syndrome due to a malignant cause survive only 30 days without radiation.

Complications

Total superior vena cava (SVC) obstruction is rare. Potential causes include indwelling catheters. Thrombolysis must be considered.

Airway compromise is unusual but may result from extrinsic compression of the superior vena cava or the trachea by the tumor mass.

Early in the clinical course of superior vena cava (SVC) syndrome (SVCS), signs or symptoms may be subtle or absent. Typically, symptoms accelerate as the underlying malignancy increases in size and/or invasiveness. Dyspnea is the most common symptom, followed by trunk or extremity swelling. Other symptoms include the following:

• Facial swelling

• Cough

• Orthopnea

• Headache

• Nasal stuffiness

• Light-headedness

Neurologic symptoms, such as dizziness and confusion, are late findings as cerebral edema occurs.

Physical examination often reveals facial or upper extremity edema. The degree of facial edema has been described as facial engorgement (as is seen in the image below).

Superior Vena Cava Syndrome in Emergency Medicine. Patient with a 4-week history of increasing facial edema and known lung cancer.

The degree of jugular venous distention varies but often progresses through the course of disease.

Other markers of lung malignancy, such as Horner syndrome, paralysis of the vocal cords, and paralysis of the phrenic nerve, are rarely present.

Stridor may occur as the syndrome progresses and airway obstruction occurs.

The diagnosis of superior vena cava syndrome (SVCS) is often made on clinical grounds alone, combining clinical presentation with an often-obtained history of thoracic malignancy.

Plain radiography is often helpful and reveals a mediastinal mass in most patients (as is seen in the image below).

Superior Vena Cava Syndrome in Emergency Medicine. Chest radiograph of a patient with known superior vena cava syndrome (SVCS) and bronchogenic carcinoma (CA).

When in doubt, venography can aid in the diagnosis, but this is usually not necessary.

Thoracic CT scanning is helpful, but the histologic diagnosis is important in initiating therapy.

In a Danish retrospective study, Andersen and Duvnjak reported that palliative treatment of malignant superior vena cava syndrome with self-expanding nitinol stents may be a safe method with good clinical effect.[9] The investigators found a 76% procedure success rate and a 96% clinical success rate. Although there were no procedure-related complications noted, 5 patients had 50% residual stenosis, 1 had stent occlusion within 48 hours of stent deployment, 1 each had stent occlusion at 2- and 4-month follow-up, and 3 patients had stent compression with 50% reduction in stent diameter at follow-up. Death in 22 patients at a mean follow-up of 3.5 months was determined to be related to their underlying malignancy.[9]

Prehospital caregivers are aware of the superior vena cava syndrome (SVCS) diagnosis only on occasion.

The usual attention to airway, breathing, and circulation (ABCs) is required.

Superior vena cava syndrome only rarely manifests as a life-threatening entity; therefore, other causes for the symptomatology must be sought.

Superior vena cava syndrome only rarely manifests as an acute emergency. Typically, the syndrome develops over weeks to months and is recognized when the typical signs of facial and upper extremity edema occur. Confusion related to associated cerebral edema or stridor from laryngeal edema and impending airway obstruction represent acute emergencies.

Attention to the ABCs is essential.

If patients are allowed to sit upright, they may experience some relief of the usual dyspnea.[10]

Stabilize the airway, as needed, and consider steroids.

If cerebral/airway edema is present, consider diuretics; however, diuretics have not shown consistent benefit in the emergency department (ED).

Endovascular shunts are increasingly used, as are thrombolytics if a thrombotic cause is present.

Cui and colleagues reported on the development of acute superior vena cava (SVC) syndrome in a 28-year-old woman with end-stage renal disease who was implanted with a left-side hemodialysis reliable outflow graft and a right-side double lumen hemodialysis catheter via internal jugular veins. The patient’s symptoms were not alleviated after catheter removal and systemic anticoagulation therapy. Eventually, she was successfully treated with catheter-directed thrombolysis, demonstrating that this method can be safely used to treat refractory catheter-induced acute SVC syndrome in end-stage renal disease patients.[11]

After a tissue diagnosis, radiation and chemotherapy may be initiated.

Over the last 20 years, considerable experience with endovascular stenting of superior vena cava syndrome has been achieved.[12, 13, 14, 15, 16] At many centers, endoprostheses have become the initial choice for palliative treatment of superior vena cava syndrome.

In a retrospective study that evaluated the self-expanding nitinol Sinus-XL stent for the treatment of superior vena cava (SVC) obstruction caused by non-small cell lung cancer (NSCLC), investigators studied 23 patients with NSCLC and acute SVC obstruction who were scheduled for urgent stent implantation. The primary study endpoints were technical success, residual stenosis < 30%, and clinical efficacy. Results provided evidence that in this palliative setting, implantation of the self-expanding Sinus-XL stent for treatment of SVC obstruction caused by NSCLC is a safe and effective urgent treatment.[17]

Emergent consultation with radiation therapy may be necessary, depending upon the acuteness of the presentation.

Because most causes of superior vena cava syndrome are related to lung cancer, a pulmonary or oncology consultation may be obtained.

Generally, considering the diagnosis in the ED is important. If the diagnosis is made de novo in the ED, only rarely is emergent consultation necessary. Exceptions include sudden airway compromise or acute superior vena cava thrombosis, which may occur from an indwelling catheter.

Steroids and diuretics have been the mainstays of ED management. However, superior vena cava syndrome (SVCS) rarely presents as an acute life-threatening emergency. As such, considering the diagnosis may be more important than the actual definitive care when making therapeutic decisions.

Class Summary

These agents decrease the inflammatory response to tumor invasion and edema surrounding the tumor mass. They have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.

Methylprednisolone (Solu-Medrol, Depo-Medrol, Medrol)

One of several steroids that may be given in ED. Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing increased capillary permeability.

Prednisone (Deltasone, Orasone, Sterapred)

Useful in treatment of inflammatory and autoimmune reactions. By reversing increased capillary permeability and suppressing polymorphonuclear neutrophil (PMN) activity, may decrease inflammation.

Class Summary

These agents may decrease venous return to the heart by decreasing preload, relieving the increased pressure in the superior vena cava.

Furosemide (Lasix)

Increases excretion of water by interfering with chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in ascending loop of Henle and distal renal tubule.

Dose must be individualized. Depending on response, administer at increments of 20-40 mg, no sooner than 6-8 h after previous dose, until desired diuresis occurs. When treating infants, titrate with 1 mg/kg/dose increments until satisfactory effect achieved.