A 77-year-old woman was transferred to our hospital with persistent chest pain. She had no previous history of coronary heart disease. Two months earlier, she had undergone a complication-free hip replacement surgery with a cemented prosthesis.
On admission, she was nearly asymptomatic, but because of elevated cardiac troponin and ST-segment elevation in the inferior and lateral leads, a coronary angiography was performed, which showed normal coronary arteries. However, fluoroscopy revealed a thin, opaque structure apparently overlying the heart. After 2 hours of observation, signs and symptoms of pericarditis were noted, and shortly thereafter, worsening ensued with progression to cardiac tamponade. After percutaneous evacuation of 250 mL blood from the pericardial cavity, her clinical condition normalized. A computed tomography scan was performed to rule out aortic dissection. The computed tomography scan and an echocardiogram confirmed the presence of a hyperechogenic rod-like structure perforating the wall of the right atrium (Figure 1A and 1B). Open heart surgery was performed the following morning.
A, Thoracic computed tomography scan of the heart. The green arrow shows the cement embolus; red arrow, the pigtail catheter inserted during pericardiocentesis. B, An echocardiogram showing a hyperechogenic rod-like structure within the right side of the heart (green arrow). Ao indicates aorta; LV, left ventricle; RA, right atrium; and RV, right ventricle.
After opening of the pericardium, which was found to be markedly inflamed, a foreign object penetrating the right auricle was removed, and the defect in the wall was repaired.
The foreign object was 54 mm long and ≈1.5 mm wide (Figure 2A). Because the patient had undergone hip replacement surgery 2 months previously, it was suspected that the foreign object could represent a cement embolus. To confirm the nature of the object, a small piece was cut off and subjected to field emission scanning electron microscopy (Figure 2B). A piece of Palacos bone cement was used as control (Figure 2C). The structures of the foreign object and the control bone cement were identical, confirming that the foreign object was in fact a bone cement embolus to the heart. The patient made an uneventful recovery.
A, A macroscopic picture of the foreign object after removal from the patient. B, A scanning electron microscopy (SEM) image of the foreign object. C, An image of the corresponding control bone cement. A Zeiss Sigma Field Emission SEM microscope with an SE2 detector and high voltage was used.
Discussion
Cement or polymethylmethacrylate is widely used in hip and knee replacement surgery. Cement is also used in vertebroplasty and kyphoplasty when vertebral compression fractures are treated percutaneously.1
Although these procedures are considered safe, serious complications may occur. One of the most feared complications after vertebroplasty or kyphoplasty procedures results from extravasations of cement into the vertebral venous circulation.2–4 The cement may migrate through the iliolumbar and epidural veins centrally toward the chambers and pulmonary arteries of the right side of the heart. Although cement embolism is often asymptomatic, more severe pulmonary embolism and cardiac perforation may result.
To the best of our knowledge, this is the first report of a patient who presented with a cement embolus to the right heart after total hip replacement. We suggest that extravasation of cement into the venous system occurred during the insertion of the prosthesis, quite analogous to what may happen during kyphoplasty procedures. Like a cast from the involved vein, the cement fragment migrates to the right heart.
Although extremely rare, cement embolization to the heart should be considered in patients presenting with chest pain after hip replacement surgery in which cemented prostheses are used. The patient gave consent to publication.
ARYAN'S BLOG 