Extensive pulmonary embolism secondary to iliac vein compression from asymptomatic postoperative urinary retention

Pulmonary embolism (PE) is a life-threatening condition caused by obstruction of the pulmonary arteries, most commonly secondary to deep vein thrombosis (DVT) of the lower extremities. Identifiable and reversible risk factors are critical, as they directly influence management and prognosis. We report an atypical case of high clot burden PE with right ventricular strain due to an unusual underlying mechanism. The patient presented with acute dyspnea and hypoxemia and was found to have bilateral pulmonary emboli secondary to extensive bilateral DVT resulting from severe postoperative urinary retention following hemorrhoidectomy. Bladder distention caused bilateral iliac vein compression, predisposing to venous stasis and thrombosis. Management included bladder decompression via catheterization, administration of tamsulosin and anticoagulation therapy. The patient was otherwise healthy, with no identifiable inherited or acquired risk factors for thrombosis. This case underscores a rare but clinically important cause of high clot burden PE and highlights the importance of considering urinary retention–related pelvic venous compression in patients presenting with unexplained venous thromboembolism.