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Cranial vena caval syndrome secondary to central venous obstruction associated with a pacemaker lead in a dog
Jennifer M Mulz1, Marc S Kraus, Margret Thompson
1Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA.
Insights
A Shih Tzu developed chylothorax after pacemaker implantation due to cranial vena caval syndrome. This condition, caused by fibrous proliferation, led to complications and euthanasia.
Area of Science:
- Veterinary Cardiology
- Interventional Cardiology
- Small Animal Internal Medicine
Background:
- Transvenous pacemaker implantation is a treatment for cardiac arrhythmias in dogs.
- Complications can arise from indwelling devices, including vascular obstruction.
Observation:
- An 11-year-old Shih Tzu presented with chylothorax three years post-transvenous pacemaker implantation.
- Imaging revealed cranial vena cava obstruction and suspected jugular and brachiocephalic vein abnormalities.
- Transesophageal echocardiography confirmed a cranial vena cava thrombus.
Findings:
- Surgical intervention (thoracic duct ligation and cisterna chyli ablation) altered pleural effusion characteristics.
- Cranial vena cava stenosis was identified via repeat imaging.
- Balloon angioplasty failed to resolve the pleural effusion.
Implications:
- Transvenous pacemaker implantation can lead to delayed cranial vena caval syndrome.
- Fibrous proliferation within the vessel lumen is a potential long-term complication.
- This case highlights the importance of monitoring for vascular complications after pacemaker placement.
Abstract:
This report describes the case of an 11-year-old castrated male Shih Tzu who developed chylothorax three years following implantation of a transvenous pacemaker. Imaging demonstrated one definitive obstruction in the cranial vena cava and 3 additional suspected filling abnormalities within both external jugular veins, brachiocephalic veins and cranial vena cava. A thrombus was visualized in the cranial vena cava via transesophageal echocardiography. Thoracic duct ligation and cisterna chyli ablation were performed, with a resultant change in the nature of the fluid from chylous to a modified transudate. Repeat angiography and computed tomography three months later demonstrated a stenosis within the cranial vena cava. Balloon angioplasty was attempted, however it was unsuccessful in decreasing pleural effusion. Palliative thoracocentesis was continued until the patient developed a lung lobe torsion, at which time euthanasia was elected. Necropsy confirmed cranial vena caval syndrome secondary to transvenous pacemaker implantation induced fibrous proliferation within the vessel lumen.
