2 The procedure
2.1.1 Vena caval obstruction is narrowing or occlusion of the caval veins (the inferior vena cava or the superior vena cava), which return blood from the body to the heart. It is most commonly caused by cancer, especially lung cancer. Patients with malignant vena caval obstruction are very ill and have a short life expectancy.
2.1.2 Standard treatments for malignant caval obstruction include radiotherapy and chemotherapy. These can cause severe adverse events and response to treatment may take several weeks. Stent placement can replace or supplement these treatments.
2.2.1 Stent placement for vena caval obstruction is a minimally invasive procedure that involves inserting a catheter into a large vein, usually in the groin, and passing it into the narrowed area under radiological guidance. A stent, which may be self-expanding or balloon-dilated, is then positioned across the narrowed area to relieve the obstruction.
2.3.1 A systematic review on the treatment of superior vena caval obstruction in lung cancer identified 23 non-randomised studies (159 patients) examining the use of stents. The review reported 95% (151/159) relief from obstruction and although recurrence occurred in 11% (17/159) of patients during follow-up (up to 8 months), long-term patency was achieved in 92% (146/159). This compared with a complete relief rate of 77% (377/487) for patients treated with any combination of chemotherapy and/or radiotherapy. Median survival ranged from 1.5 to 6.5 months in the 13 studies that reported survival outcomes. For more details, refer to the Sources of evidence section.
2.3.2 The evidence showed that the response to treatment was more rapid for patients receiving stents than for patients receiving radiotherapy or chemotherapy. One study with historical controls reported relief of obstruction immediately or within 48 hours in patients receiving stents, compared with no change before 2 weeks in patients receiving radiotherapy. For more details, refer to the Sources of evidence section.
2.3.3 The Specialist Advisors considered stenting to be highly effective. The only concern they raised was the possible inappropriate use of stents in some young patients with a mediastinal mass on chest X-ray that may disappear quickly with chemotherapy.
2.4.1 Few adverse events were reported. In the largest study reporting complications: 3% (2/76 patients) had misplaced stents; 1% (1/76) required anticoagulation; 1% (1/76) experienced transient chest pain; and 1% (1/76) required blood transfusion. Adverse events in another study included stent obstruction, 12% (6/52), and stent migration, 2% (1/52). For more details, refer to the Sources of evidence section.
2.4.2 The Specialist Advisors had few concerns about the safety of this procedure. They considered the main potential adverse events to be perforation or rupture of the vena cava, migration of the stent, and embolisation.
2.5.1 Most evidence relates to superior vena caval obstruction in adults with carcinoma of the lung.
2.5.2 It was noted that there was less evidence in children, and that the procedure would normally be undertaken in specialist paediatric cardiology units.