Reconstruction of the Superior Vena Cava with the Aid of an Extraluminal Venovenous Jugulo-Atrial Shunt

Abstract

A 57-year-old woman had chronic benign superior vena cava syndrome related to the long-term use of multiple central venous catheters for chemotherapy. Treatment included resection of the obstructed segment and repair of the superior vena cava with an autologous pericardial patch. Intraoperatively, return venous flow was maintained with an extraluminal venovenous jugulo-atrial shunt. The shunt relieved upper-body hypertension and congestion, resulting in early extubation and a short, smooth postoperative course.

Superior vena cava (SVC) syndrome is a common obstructive condition that is usually due to a malignant tumor but that, in 10% to 20% of cases, ^1,2 is due to a benign cause. One increasingly frequent benign cause of SVC syndrome is stenosis related to the long-term use of multiple central venous catheters. ^1–5 In such cases, use of a venovenous jugulo-atrial shunt can facilitate repair or reconstruction by providing uninterrupted venous return during intraoperative clamping of the SVC.

Case Report

Medical History

In October 1998, a 57-year-old woman was admitted to our hospital for stenosis of the superior vena cava. The patient had a history of leukemia, for which she had received chemotherapy in 1991 and 1992. During chemotherapy, several in-dwelling central venous catheters had been placed in both subclavian and internal jugular veins. In 1992, the patient began to have increasing dyspnea and edema of the face, neck, and upper extremities. Six months before her October 1998 admission, she began to have headaches, which grew in frequency and intensity. She also began to have blackouts, which lasted for only a few seconds; these episodes were often preceded by a headache and caused no lingering neurologic deficits.

Upon the patient's admission to another hospital in May 1998, physical examination was remarkable only for signs of SVC obstruction. The diagnosis was confirmed by computed tomographic scanning and magnetic resonance imaging. Angiography revealed 100% occlusion of the SVC (Fig. 1) at its junction with the azygos vein. Numerous collateral vessels were present. After angiography, the patient underwent percutaneous transluminal balloon angioplasty, which failed to dilate the stenosed SVC. She was then referred to our hospital for surgical treatment.

Fig. 1 A) Angiogram showing 100% occlusion of the SVC at its junction with the azygos vein; and B) schematic drawing of this angiographic finding.

RIJV = right internal jugular vein; SVC = superior vena cava; RA = right atrium

Operative Procedure

Exploration of the SVC via a median sternotomy confirmed the presence of stenosis at the level of the azygos vein. The stenosis, which measured about 3 cm in length, extended above and below the azygos-SVC junction. The segment between that junction and the right atrium was completely occluded (Fig. 2). In addition, the innominate and right subclavian veins were occluded, fibrotic, and cord-like. Several dilated collateral veins were noted. Proximal to the stenosis, the right internal jugular vein also appeared to be dilated.

Fig. 2 Schematic drawing of the operative findings.

RA = right atrium; RIJV = right internal jugular vein; SVC = superior vena cava

To maintain venous return from the upper body during SVC clamping and reconstruction, we used an extraluminal venovenous jugulo-atrial shunt (Fig. 3A) and kept a cardiopulmonary bypass pump on standby. After heparinization was instituted, a purse-string suture was placed in the right internal jugular vein 2 cm proximal to the planned resection line, and a 2nd purse-string suture was placed in the right atrium. Through these sutures, an 18F femoral arterial cannula was inserted into the jugular vein, and a 24F aortic cannula was placed into the right atrium. A saline-filled loop of pump tubing was connected to both cannulae. Before jugulo-atrial bypass was started, the shunt's cannulae and tubes were carefully deaired.

Fig. 3 Schematic drawings showing: A) placement of the jugulo-atrial venous shunt; B) placement of clamps prior to resection of the occluded superior vena cava segment; C) creation of the posterior suture line; D) angioplasty of the anterior wall of the superior vena cava with an autologous pericardial patch; and E) the completed reconstruction after removal of the cannulae.

RA = right atrium; RIJV = right internal jugular vein; SVC = superior vena cava

Vascular occluding clamps were applied to the SVC, right internal jugular vein, and azygos vein (Fig. 3B). Exploration of the innominate vein revealed fibrosis and no blood flow, so the vein was ligated. The SVC was transected above and below the fibrotic segment, which was then excised. The proximal and distal SVC stumps were mobilized, which enabled tension-free approximation of their edges. A small vertical incision was made in the anterior surface of each stump to enable matching of their diameters. Beginning on the posterior aspect of the stumps, we approximated the edges with running 5-0 polypropylene sutures (Fig. 3C).

The anterior wall of the SVC was reconstructed with a 6 × 8-cm diamond-shaped, glutaraldehyde-treated, autologous pericardial patch (Fig. 3D). Reconstruction yielded immediate relief of the obstruction and a near-normal-looking SVC (Fig. 3E). The SVC was de-aired, the clamps were removed sequentially, and the effects of heparin were reversed with protamine sulfate. The operation was then completed routinely. Before leaving the operating table, the patient underwent extubation and neurologic assessment. Her facial congestion and cyanosis resolved immediately after surgery, and the edema of the face, neck, and upper torso resolved during the ensuing few days. She was discharged from the hospital on the 6th postoperative day, without neurologic deficits or a need for anticoagulants. One month postoperatively, follow-up vascular Doppler ultrasonography showed satisfactory graft patency and blood flow.

Discussion

Superior vena cava syndrome is frequently encountered by cardiovascular clinicians. In this condition, SVC obstruction increases the venous pressure in the head and neck, elevating the cerebral venous pressure to anywhere from 20 to 50 mmHg. ^1–6 Most cases are due to malignant disease, but 10% to 20% ^1,2 arise from benign disorders such as chronic fibrosing mediastinitis or compression caused by an expanding thoracic aneurysm. One potential benign cause, which is steadily increasing in frequency, is stenosis and obstruction of the SVC associated with the use of long-term central venous catheters or permanent pacing electrodes.

Several surgical techniques are available for repairing, reconstructing, replacing, or bypassing the obstructed SVC. Ideally, the procedure should be tailored to suit each individual patient. Whichever method is used, the goals ^7,8 are to relieve symptoms, to minimize the risk of complications (infection, central nervous system sequelae, and upper respiratory edema and stridor), and to ensure long-term patency of the SVC. These goals are achieved by providing a high-flow (750-2000 mL/min) conduit for venous return from the upper body. Whenever possible, one should perform an anatomic reconstruction, thereby avoiding the need for perioperative and postoperative anticoagulants.

If few or no collateral veins provide significant drainage of the upper body, prolonged intraoperative clamping of the return venous flow can result in potentially fatal cerebral edema or postoperative neurologic deficits. In our patient, this factor was particularly important because of her history of headaches and blackouts. ^9,10 In such cases, placement of an intraluminal or extraluminal shunt between the right internal jugular vein or brachiocephalic trunk and the right atrium establishes continuous venous return to the right atrium, preventing neurologic complications. By eliminating the time constraints posed by cross-clamping of the SVC, a jugulo-atrial shunt facilitates complete repair or reconstruction. It prevents the systemic hypotension that occurs when the clamping of a patent SVC reduces the arteriovenous gradient in the cerebral territory. Moreover, a shunt provides immediate relief of upper-body venous hypertension and congestion, resulting in early extubation and a short, smooth postoperative course.

Various materials have been proposed for SVC repair or reconstruction. Currently, 2 autologous materials are used: 1) pericardium, which may be fashioned in the shape of a patch or tube; and 2) saphenous vein grafts, which may be split longitudinally and sutured in spiral fashion around a 40F stent, so as to have a diameter of 12 mm. The preferred synthetic material is polytetrafluoroethylene (PTFE), which can take the form of a thin membrane or patch for repairing the SVC; alternatively, PTFE can take the form of a tube graft (commonly with external reinforcing rings) for reconstructing or bypassing the vessel. 4,7,8,11–15 Most surgeons, including us, favor autologous pericardium because it is easy to procure and prepare. In contrast, spiral saphenous vein grafts require 60 to 90 minutes to harvest and prepare. Unlike prosthetic materials, autologous pericardium involves no risk of infection and does not necessitate anticoagulation therapy.

Conclusion

Catheter-induced SVC syndrome is a potentially serious condition that is occurring with increasing frequency and that often requires surgical correction. Intraoperative insertion of an extraluminal veno-venous jugulo-atrial shunt enables uninterrupted venous return from the upper body, allowing time for complete repair of the SVC. Reconstruction with an autologous pericardial patch is a safe, simple method that avoids the need for postoperative anticoagulation.