Acquired systemic-to-pulmonary venous shunts are rare, occurring when collateral vessels form between systemic and pulmonary veins, bypassing the right heart and alveolar spaces. We present the case of a 29-year-old male with recurrent prosthetic tricuspid valve (TV) endocarditis. Following redo TV surgery, he developed refractory hypoxemia, resistant to diuresis and supplemental oxygen. Dedicated imaging, including bubble study, computed tomography, and technetium-99m macroaggregated albumin scan, confirmed extensive systemic-to-pulmonary venous shunting. The patient underwent collateral vein embolization procedures, resulting in significant clinical improvement. This case emphasizes the importance of multimodal imaging and multidisciplinary management in the diagnosis and treatment of rare shunts.