Superior Vena Cava (SVC) syndrome [
2,
3] is a very rare but debilitating complication after pacemaker lead implantation. Symptoms depend on how quickly the obstruction establishes; however, the insurgence of thrombosis caused by pacemaker leads seems to be unrelated to the time elapsed from the procedure [
4]. Most patients are often less symptomatic due to the development of collateral circulation. Several causes lead to this syndrome. The most common is malignancy (85%): lung cancer, lymphomas; metastasis to the mediastinum from breast cancer or gastrointestinal tumors, primary mediastinal tumors. The mechanisms most involved are extrinsic compression and neoplastic infiltration of SVC. Less commonly, non-oncologic causes may occur: infections, spontaneous thrombosis, and iatrogenic causes. Among the latter, radiotherapy on the mediastinum and thrombosis or infections of intravascular devices (central vein catheters, cardiac defibrillators, and pacemaker wires) are becoming increasingly common. However, in a large series from Rice [
5], a pacemaker was considered to be the cause of SVC syndrome in only 1 out of 78 cases (1.28%). Procedures performed on venous vasculature, causing a possible intimal injury or vein stenosis, provoked by transvenous leads, seem to be the most reasonable explanation for the observed complication. The treatment of SVC syndrome involves the use of medical, interventional, or surgical therapy. Medical management includes anticoagulants or thrombolytics; interventional procedures commonly performed include balloon angioplasty and stenting. The duration of symptoms before the onset of thrombolytic therapy, can often guide the most appropriate approach. The success rate of thrombolytic therapy is greater if treatment is begun less than or equal to 5 days after the symptoms started. Endovascular repair is less invasive but equally effective compared to the surgical approach. The open repair treatment is mostly used in SVC syndrome due to mediastinal fibrosis [
2]. When the cause is pacemaker implantation two treatments are possible. The first one is the lead removal, stent implantation, and reimplantation of new leads, but the long-term efficacy of this approach is unknown. The other one is balloon dilatation of the vein with stent placement [
1]. Adjuvant anticoagulation is usually used after angioplasty. In our case, the patient refused the endovascular treatment so the medical approach was adopted. Furthermore, due to the long persistence of symptoms, we speculated that the thrombosis was not acute, and hypothesized that anticoagulation should restore a favorable balance between thrombosis persistence and physiologic fibrinolysis, leading to thrombus resolution. The anticoagulation treatment of upper extremity deep vein thrombosis (UE-DVT) has not been standardized yet; however, the current practice is to start warfarin after 5 to 7 days of low-molecular-weight heparin. Currently, there are no completed randomized trials of direct oral anticoagulants (DOACs) in UE-DVT; nevertheless, DOACs are increasingly used in real-world experiences with an adequate profile of efficacy and safety [
6]. Thus, treatment of iatrogenic superior vena cava thrombosis with a DOAC represents an interesting new approach, to be validated in prospective trials against the current standard (heparin followed by warfarin).