A 28-year-old woman, weight 55 kg and height 162 cm, initially presented to the emergency department of an outside hospital with a 2-month history of chest distress, cough and dyspnea. The patient’s symptoms did not improve significantly after oxygen therapy or anti-asthma medication combined with aerosol inhalation. The patient was later transferred to the cardiovascular surgery department in the authors’ institution with aggravation of the above symptoms. Echocardiography revealed severe tricuspid regurgitation and congenital heart disease, including a ventricular septal defect and rupture of the right coronary sinus aneurysm. An abdominal computed tomography scan revealed that the inferior vena cava and hepatic veins were widened. The preoperative laboratory examination was unremarkable. For invasive hemodynamic measurement, a Swan-Ganz catheter (Edwards Lifesciences, Irvine, CA) was inserted through an 8-F percutaneous introducer sheath placed in the right internal jugular vein, and a central venous catheter was inserted into the right subclavian vein without any difficulties. The pulmonary artery pressure waveform suggested that the catheter was successfully floated into the pulmonary artery. The patient underwent ventricular septal defect repair, aortoplasty and tricuspid valvuloplasty under cardiopulmonary bypass. After obtaining the hemodynamic indexes postoperatively, the Swan-Ganz catheter was found difficult to withdraw when it was pulled out to 35 cm mark. The cardiovascular surgeons and intensive care physicians suggested transporting the patient to interventional radiology. The chest X-ray showed that a portion of the Swan-Ganz catheter coiled on the central venous catheters at the level of the superior vena cava and formed a knot approximately 1 cm in diameter. Under X-ray guidance, the interventional radiologist first removed the central venous catheter smoothly. Then, the Swan-Ganz catheter was gently pushed into the right ventricle to provide more space to uncoil, and then the catheter returned to its original coiled configuration. Finally, the Swan-Ganz catheter was successfully withdrawn through the percutaneous introducer sheath. A closer inspection of the Swan-Ganz catheter coiled on the central venous catheter is shown in Fig.. During this procedure, the patient’s hemodynamics were not significantly affected, and the patient did not present any complications or cardiovascular injury. Valvar damage was excluded by echocardiography.