Title
Endovascular Stenting for Superior Vena Cava Occlusion Secondary to Postradiation Fibrosis
Introduction
Superior vena cava (SVA) syndrome commonly results from malignant obstruction caused by direct invasion or external compression of the SVC by a pathological process. Rarely, SVC obstruction can occur due to postradiation vascular fibrosis in patients who received prior thoracic radiation therapy predating their symptoms by several years. We present a case of SVC obstruction diagnosed 18 years after chest radiation and treated with an endovascular approach.
Clinical Case
A 47-year-old male was referred for evaluation of exertional chest pain. The pain was described as heaviness that occurs during exercise and severely limits his active lifestyle. He has been coping with his symptoms for the past 15 years, during which he underwent multiple non-diagnostic cardiac evaluations. Additionally, he noted head fullness exacerbated by bending forward, recurrent headaches and nasal congestion, and distended veins over his lower chest and upper extremities swelling when he exercises. His past medical history was significant for a history of Hodgkin lymphoma treated successfully with chest radiotherapy 18 years ago with no evidence of recurrence by surveillance PET scans. His physical examination was significant for mild neck veins distention. Given his history and the timing of his symptoms, starting three years post chest radiation, postradiation fibrosis of the SVC was suspected. A gated chest CTA was performed to evaluate for SVC obstruction and rule out mediastinal masses and coronary disease. SVC occlusion was seen with extensive collateral circulation through the azygos-hemiazygos, internal mammary, and lateral thoracic veins. Additionally, extensive pericardial varices were seen. Treatment options were discussed with the patient and an endovascular approach was planned. Right basilic and common femoral vein accesses were obtained. Venography and pressure measurement were performed simultaneously from the right atrium and right brachiocephalic vein. Total occlusion of the SVC with extensive collateral circulation were noted, in addition to 12mmHg pressure difference. Due to the presence of a favorable proximal cap, a destination sheath was inserted from the CFV and the occlusion was crossed using 0.018" wire and a micro-catheter. Balloon angioplasty using a 3.0mm balloon was performed to facilitate the advancement of intravascular ultrasound (IVUS) to further evaluate the lesion. Severe fibrosis with no thrombotic component was noted. Sequential balloon angioplasty with high atmospheric pressures was needed to expand the occlusion was performed. IVUS was performed to evaluate reference vessel diameter and aid in stent deployment. A 16x60mm WALLSTENT was then deployed and post dilated with a 16 mm balloon. Final IVUS and angiography showed excellent immediate results. On follow up, the patient has resolution of his symptoms, with significant improvement in his exercise tolerance.
Discussion
Postradiation fibrosis, with subsequent SVC obstruction, can occur in cancer survivors and present several years post chest radiation therapy. Endovascular therapy is a feasible, non-invasive therapeutic option with excellent, at least, intermediate-term results.