Iatrogenic Device Induced Superior Vena Cava Syndromes

In this issue of Vascular Disease Management, Patel et al report a case of superior vena cava (SVC) syndrome secondary to transvenous electrode placement that was successfully treated by excimer laser-assisted lead removal followed by balloon angioplasty and stenting. The patient had subsequent symptomatic resolution. Superior vena cava syndrome merits comment here.

There has been a dramatic increase in the use of pacers, defibrillators, and resynchronization therapy. There has also been an increase in the use of indwelling central lines for chronic fluid and intravenous medication administration, particularly in patients receiving chemotherapy. Any transvenous line can mechanically injure a vein or obstruct cross-sectional area. These lines can become infected. Drugs administered via central lines can irritate and induce strictures. Pacer leads can become dysfunctional and need to be replaced or abandoned. Based on these observations I think it is probable that clinicians will increasingly encounter this clinical problem. 

With the development of appropriateness guidelines, more patients have received new electrophysiologic devices with more transvenous leads. Many of these new devices require multiple leads to achieve therapeutic endpoints. More leads take up more cross-sectional area and therefore have greater potential to be occlusive. Patient leads can become profoundly scarred in place, particularly at the SVC-atrial junction. Most dysfunctional leads are presently capped and left in place, with additional leads placed, potentially increasing occlusive risk, although this may decline in the future with advancements in leadless technology. Should there be some form of vascular surveillance in patients with multiple indwelling leads and catheters? How should we treat these patients with total or high-grade venous obstruction? How important is it to treat SVC occlusions? 

Great strides have been made in lead removal with improved mechanical and laser-mediated devices that have been shown to be effective with relatively low but not zero risk in removing even heavily scarred leads. Despite this, relatively few leads are removed on a percentage basis (fewer yet with obstruction as the basis of removal). Perhaps this is because of risk or cost or poor understanding of therapeutic options. Are there risks or costs associated with no therapy including but not limited to diminished future therapeutic options, patient discomfort, or cosmetic effects? If leads are removed, should these patients be treated with simple percutaneous transluminal angioplasty, stenting, or perhaps in the future with drug-eluting balloons? How can we limit the risk of treatment? Patel et al utilized intravascular ultrasound for vascular measurement and to precisely place the stent without extending into the atrium. What other tips and tricks may yield better results making intervention more desirable? We need consensus on how to evaluate, when and how to treat, and how to follow iatrogenically induced SVC stenosis and occlusions.