Title: Case Series: Variable Presentation of Polymethyl Methcrylate Pulmonary Embolism
Author(s): Rasik Neupane, MD; Amrit Lama, MD; Matthew D Cheng, MD; Molly Howsare, DO; Manuel A. Bautista, MD
Email: rneupane@mercy.com
Introduction: Vertebroplasty and Kyphoplasty are techniques used to treat painful vertebral compression fractures with polymethyl methacrylate injection.[1] Risk of pulmonary embolism from cement embolism (PCE) ranges from 3.5% to 23 % R. [2] We present two cases of PCE resulting from kyphoplasty.
Case Report(s): Case 1- A 76 years old female with past medical history of chronic obstructive pulmonary disease, prior smoking, hypertension, congestive heart failure, GERD and paroxysmal atrial fibrillation on anticoagulation, presented to the hospital with worsening chest pain and back pain. Patient was saturating well on room air and lab findings were within normal limits. Two days prior to presentation she had undergone a T10 body balloon kyphoplasty with use of polymethylmethcrylate. CTA of the chest was completed and revealed scattered bilateral pulmonary artery cement embolism in distal branch locations. The patient was continued on Rivaroxaban, which she was previously prescribed for PAF along with other symptomatic treatment and was followed in pulmonary clinic on discharge.
Case 2- A 38 years old female with a past medical history of Discoid lupus erythematosus, provoked deep venous thrombosis not on anticoagulation, motor vehicle accident with multiple back fractures S/P kyphoplasties presented with complaints of progressively worsening dyspnea ongoing for several months. Physical examination showed multiple hypopigmented lesions on face and hands with diminished breath sounds on auscultation. Chest radiograph showed high attenuation curvilinear and nodular densities in the mid and lower lung zones suggesting methcrylate embolization. CT without contrast revealed small clustered peripheral emboli consistent with embolized polymethyl methcrylate. Patient was discharged on symptomatic treatment without anticoagulation and was followed in the out-patient in pulmonary clinic.
Discussion: Leakage of polymethyl methacrylate (PMMA) into the valveless paravertebral venous system and into the thoracic venous system causes pulmonary embolism [1]. As PMMA is a low-viscosity substance forceful injection into collapsed vertebral bodies has significant risk of extravasation. [2] The clinical presentation may vary from being an asymptomatic finding to pulmonary symptoms such as tachypnea, hemoptysis, dyspnea, and chest pain. Treatment options include supportive care, and anticoagulation in cases with no or minimal symptoms. In severe cases embolectomy may be performed. Despite potential risk of PCE, optimal management is still unclear with limited data in the literature. The Above cases adds to different presentation of cement emboli despite being on long term anticoagulation and would help in developing guidelines on standard of care.
