Use of Radiofrequency Energy and Covered Stents in Patients
with an Occluded Superior Vena Cava and Requiring Endocardial
Pace

Obstructions of the caval veins may develop in various clinical settings in subjects with tumoral lesions, after surgery on the caval veins — as in the Mustard/Senning operation, after radiation therapy, or due to central lines, dialysis catheters and pacing wires.^1–4 In particular, patients with a history of multiple cardiac surgical procedures or with a history of infections of the pacemaker site and electrodes may easily develop an iatrogenic occlusion of the venous access.² Various kinds of interventions have been performed in these subjects, including balloon dilation and bare-metal stent implantation.^1–4
In this article, we report on 3 patients with complete interruption of the superior vena cava (SVC) in whom we used radiofrequency energy and covered stents to recanalize the SVC and to allow for implantation of endocardial pacemaker leads.

Case Series
Case 1. A 70-year-old male with severe aortic regurgitation and post-ischemic dilated cardiomyopathy underwent aorto-coronary bypass implantation of a mechanical valve in the aortic position (St. Jude Medical 23, St. Paul, Minnesota). Subsequently, he underwent DDD pacemaker implantation due to a high-degree II° atrioventricular block. Three years later, due to the occurrence of an infection in the pacemaker location, the electrodes and the battery were completely removed. Six months later, when it was decided to implant a DDD (dual-mode, dual-pacing, dual-sensing) pacemaker, the SVC was found to be completely closed with no connection with the heart. The blood flow drained via the azygos vein toward the inferior vena cava (Figure 1).

Case 2. A 48-year-old female with a history of cardiac surgery for a sinus venosus atrial septal defect (ASD) and partial anomalous return of the pulmonary veins developed severe bradycardia and needed implantation of an endocardial pacemaker. During the procedure, a complete and long occlusion of the SVC was found.
Case 3. A 40-year-old male underwent surgical closure of a perimembranous ventricular septal defect and patent ductus arteriosus when he was 2 years old. He experienced complete atrioventricular block after surgery and he underwent implantation of an epicardic DDD pacemaker. When he was 30 years old, an endocardial system was implanted. Two years later, due to the occurrence of endocarditis and infection of the pacemaker site (both on the right and left sides), the electrodes and the battery were removed. An epicardial DDD pacemaker was implanted.
At the age of 39, the patient experienced syncope and malfunctioning of the pacemaker. In fact, inhibition of the pacemaker was apparent due to oversensing. This event was related to a partial rupture of the external covering of the epicardial leads without a loss of the continuity of the conductor. Therefore, it was decided to implant an endocardial pacemaker. The venogram before the implantation procedure showed an absence of the left subclavian vein. The right subclavian vein was present, but it was not possible to reach the heart due to a complete interruption of the SVC.

Procedure. After discussing the cases, it was decided to attempt radiofrequency perforation and reconstruction of the SVC by using covered stents. After having obtained written, informed consent, the procedures were performed with the patients under general anesthesia with orotracheal intubation.
Angiographic images were obtained contemporaneously in the SVC and in the right atrium. In all cases, a long interruption of the SVC was observed (Figure 1).
The radiofrequency system (Baylis MedComp, Inc., Montreal, Canada), made with a Nykanen 0.024 inch radiofrequency guidewire and a coaxial catheter was advanced inside a multipurpose or a right Judkins coronary artery guiding catheter placed from the inferior or the SVC, according to the patient’s anatomy, aiming to direct the wire toward the interrupted segment (Figure 1). Energy of up to 15 Watts was delivered for 3–5 seconds repeatedly.

During the first attempt in Cases 1 and 2, a false track was created, but proved to be uneventful. The SVC in Case 1, and the right atrium in Case 2, were successfully joined by the radiofrequency wire on the second attempt. In Case 3, the radiofrequency system was advanced from the SVC, and a 10 mm goose neck snare was placed in the proximal segment of the SVC in order to help direct the radiofrequency wire (Figure 3). In all cases, the radiofrequency wire was captured with a 10–15 mm Goose Neck^® snare (ev3, Inc., Plymouth, Minnesota) (Figure 1). A veno-venous circuit was thereby created between the right inferior vena cava and the right internal jugular vein. Predilatations were performed by using coronary artery and peripheral angioplasty balloons (Table 1). A 0.035 inch Amplatzer Super Stiff^™ guidewire (Boston Scientific Corp., Natick, Massachusetts) was exchanged over the circuit and used to place a 12–13 Fr Mullins long sheath (William Cook ApS Europe, Bjaeverskov, Denmark). Several covered stents were deployed in a sequentia and partially overlapping fashion over the closed area in all 3 patients (Table 1).

The procedure time was between 110 and 130 minutes, while the fluoroscopy time was between 54 and 60 minutes. At the end of the procedure, the connection between the SVC and the right atrium was completely achieved in all three cases (Figure 2), and a DDD pacemaker was successfully implanted in all patients. At this point, the patients were fully heparinized and received antibiotics. The patients’ recovery was uneventful and they were discharged home three days after the procedure with a therapy with warfarin (INR target: 2–2.5) for 6 months. No problems were reported at 6- and 9-month follow up.
Discussion. Radiofrequency energy was originally developed for electrophysiological ablation procedures. Interventional cardiologists have used this type of energy as well. However, there are some major differences between these uses, as highlighted by Benson et al.⁵
In the field of structural heart diseases, radiofrequency energy was initially used to perforate pulmonary valve atresia.⁶ More recently, radiofrequency has been used to create an ASD,⁷ to re-open chronic obstruction of the pulmonary artery,⁸ in the therapy of intrastent coronary stenosis in adults,⁹ and for chronically occluded arteries supplying the limbs.¹⁰
In a recent paper, Schaeffler et al¹¹ reported the case of an 8-year-old girl who developed protein-losing enteropathy and elevated central venous pressure due to the occlusion of a surgically redirected anomalously draining left SVC. Cardiac catheterization showed complete occlusion of the anastomosis. Complete restoration of blood flow was achieved with radiofrequency perforation, angioplasty and subsequent implantation of a P308 Palmaz stent.¹¹
We chose to use radiofrequency in our patients also. In fact, we think that a more controlled lesion can be obtained with radiofrequency. Furthermore, in our patients, we decided to implant covered stents because we thought that such stents might increase procedural safety. In fact, radiofrequency perforation may create false tracks, and part of the path may be outside the vessel wall. Furthermore, all our patients had very long, interrupted tracks. A bare-metal stent may pose the risk of bleeding between the stent cells.
Finally, in our third patient, we used the opened 10 mm gooseneck placed in one of the occluded segments as a target for the radiofrequency wire, which helped reduce the risk of creating a false track and the duration of the procedure.
To the best of our knowledge, our patients are the first in whom radiofrequency energy and covered stents have been used together to reconstruct the SVC. In all three of our patients, this intervention allowed for the successful implantation of transvenous leads of an endocardial pacemaker, thereby avoiding the need for surgical reconstruction of the venous access to the heart. At follow up, no problems were noted.
Conclusion. Radiofrequency energy and the use of covered stents may be very useful in patients needing endocardial pacemaker implantation who have complete and long obstruction of the SVC.

References

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