C63-36 Multilobar Pulmonary Cement Embolism After Cement Augmented Thoracolumbar Reconstruction

Abstract Introduction Pulmonary cement embolism (PCE) is an uncommon but recognized complication of cement-augmented spine surgery. Polymethyl-methacrylate (PMMA) may enter the venous plexus and lodge in pulmonary arteries. Once lodged, PMMA can trigger polymerization-dependent endothelial activation with surface thrombosis and propagation (1). Cement leakage is commonly reported (∼ 87%), of which symptomatic pulmonary embolism (PE) occurs in 1.7 to 6.8% (1,2). Risk factors include low cement viscosity, higher fracture grade, more treated levels, thoracic location, and tumor-related fractures (1,2,4,5). Case Report A 52-year-old man with opioid use disorder, prior Serratia osteomyelitis, and recent Candida hardware infection on fluconazole presented with profound weakness and back pain. Patient underwent removal of T10-T12 hardware, posterior instrumentation T6-T9, fusion T6-L4, and Smith-Petersen osteotomies (T9-T10) under fluoroscopy. Due to poor bone quality, pedicle screws at T6-T8 were cement augmented with PMMA. There were no intraoperative complications. On post-operative day 3, patient developed pleuritic left-sided chest pain and new oxygen requirement. CT angiography revealed numerous markedly hyperattenuating, branching intraluminal opacities in left upper-lobe and right lobar and subsegmental arteries, typical of PCE (Image 1). Concomitant imaging showed complete left lower-lobe and lingula collapse and partial collapse of the posterior left upper lobe with large left pleural effusion which was subsequently drained. Echocardiography showed no right-heart strain or PFO. Duplex was negative for DVT. Anticoagulation (AC) was initially deferred to prioritize parapneumonic effusion control. A left thoracostomy catheter was placed and removed on post-operative day 4. Broad spectrum antibiotics, Cefepime and vancomycin, were given for suspected pneumonia. After multidisciplinary review recognizing limited evidence for routine AC in PCE, unfractionated heparin infusion with no bolus was initiated after thoracotomy tube placement. Following explanting thoracotomy tube, the patient was then transitioned to apixaban. Oxygen requirement secondary to atelectasis improved to 2 L with optimized multimodal analgesia. Discussion This case links cement-augmented thoracic fixation to symptomatic multilobar PCE recognized by high-density, tubular and branching arterial opacities (1, 5). Key insights include optimal cement viscosity or “toothpaste” consistency, recognition of high-density linear or branching opacities on chest radiography and adjusting CT windowing (bone or non-contrast) to cement visibility (1, 2). Most PCEs are managed conservatively or with AC and surgical/interventional radiological intervention is reserved for large, symptomatic central emboli (1, 7, 8). Early recognition, targeted imaging, and a stepwise multidisciplinary approach remain key to favorable short-term outcomes. This abstract is funded by: None