Pulmonary cement embolism after vertebroplasty

Thromb Haemost 2006; 95: 388–9 Percutaneous vertebroplasty is widely used to relieve the pain and to increase the bone strength of vertebral bodies in patients with symptomatic osteoporotic collapse, osteolytic metastasis, myeloma or after traumatic injury. Complications reported in large studies are rare and essentially local, including radicular pain and spinal cord compression. Cement extravasation is a very frequent occurrence in vertebroplasty. It has been reported to occur in 38% to 73% of patients with malignant collapse (1), and in 30% to 65% of patients with osteoporotic vertebral collapse (2). Cement leaks in the basivertebral veins have been reported in 5% to 17% of cases (3). How often cement embolizes to the lungs is unknown because patients are not routinely screened with chest imaging after the procedure. However, a recent retrospective study revealed cement pulmonary embolism in 4.6% of patients after vertebroplasty or kyphoplasty (4). The chest radiographic findings consisted of multiple dense opacities with a tubular and branching shape distributed diffusely throughout the lungs. Literature data suggest that most patients remain asymptomatic (4). However, severe outcomes requiring pulmonary embolectomy (5) or resulting in death have been reported (6, 7). In all reported symptomatic cases, pulmonary symptoms developed immediately after percutaneous vertebroplasty. Standard treatment with anticoagulation allowed resolution of symptoms in the great majority of cases and may be considered the treatment of choice in the absence of acute respiratory distress. One case of polymethyl-methacrylate cement pulmonary embolism associated with a paradoxical cerebral arterial cement embolism has been reported in a patient with right to left shunting through a patent foramen ovale (8). We report here the case of extended bilateral pulmonary embolism of acrylic cement that became symptomatic two weeks after cementoplasty. A 58-year-old female, treated for mild hypertension, suffered from a local trauma with vertebral fractures of L2 and L3 associated with persistent lumbar pain. Her past medical and surgical history was otherwise unremarkable and she had no family or personal history of venous thromboembolic disease. She underwent percutaneous vertebroplasty with 6 ml of polymethyl-methacrylate cement under continuous biplane digital fluoroscopic control. She stayed in the hospital for 24 hours. No bed rest or persistent immobilisation was reported after the procedure, and the patient had no other risk factors for venous thromboembolic disease. No complication was reported either during or immediately after the procedure. Two weeks later, she presented to the emergency ward with dyspnea, tachypnea and thoracic pain. Plasma D-dimer level was elevated (3000 μg/l). Helical computed tomography revealed extensive right central pulmonary embolism of acrylic cement and thrombotic material in close relation with the foreign material (Fig. 1). Many smaller segmental pulmonary cement emboli were seen both in right and left lungs. Anticoagulation was promptly initiated with low molecular-weight-heparin at therapeutic dosage (once daily subcutaneous injection of Nadroparin 171 U/kg/day) followed by oral anticoagulation. This treatment, associated with non-steroidal anti-inflammatory drugs because of chest pain, dramatically improved patient’s symptoms within 24 hours. Thrombophilia was extensively searched for: antithrombin, protein C, and protein S were within the normal range; no antiphospholipid antibodies (lupus anticoagulant, IgG anticardiolipin) were detectable; mutation for factor V Leiden and prothrombin mutation (G20210A) were negative. Echocardiography performed two weeks after the acute respiratory symptoms was normal and a control exam performed 12 months later was unremarkable and did not show any indirect signs for pulmonary hypertension. Standardized six-minute walk tests per-