Thoracic Duct Obstruction as a Cause of Chylous Ascites After Pacemaker Implant.

BACKGROUND: Transvenous leads of cardiac implantable electronic devices (CIEDs) can cause central venous stenosis, impairing thoracic duct outflow, and result in chylous effusions. CASE SUMMARY: A 48-year-old man developed refractory chylous ascites/chylothorax after pacemaker implantation. Magnetic resonance lymphangiography demonstrated thoracic duct dilatation and mesenteric reflux secondary to venous stenosis. Thoracic duct thrombolysis provided only temporary improvement. Transvenous lead extraction, balloon venoplasty, and leadless pacemaker implantation resulted in complete resolution. DISCUSSION: CIED-related venous obstruction can cause lymphatic hypertension with chylous ascites/chylothorax by impairing thoracic duct drainage. Unlike direct thoracic duct injury, venous obstruction disrupts lymphatic outflow rather than causing immediate leakage. Definitive treatment requires relief of the venous obstruction. Lead extraction with venoplasty restores lymphatic drainage, whereas leadless pacing avoids further transvenous venous injury. TAKE-HOME MESSAGES: CIED-related venous stenosis should be considered in patients with unexplained chylous effusions. Lead extraction with venoplasty can restore lymphatic drainage, and leadless pacing is an effective alternative.