Pulmonary Cement Emboli After Kyphoplasty: A Case Of Bilateral Pulmonary Emboli And Exacerbation Of Interstitial Lung Disease

Abstract

Introduction/Objective Osteoporosis often complicates the management of vertebral conditions, including spinal stenosis and vertebral fractures in the geriatric population. In addition to pharmacologic pain management; surgical interventions are employed if the pain is not adequately managed. The surgical interventions include vertebroplasty and kyphoplasty. These procedures involve the introduction of a cement polymer, Polymethylmethacrylate (PMMA), into the vertebral body. Cement leakage is a reported complication more commonly seen in vertebroplasty (30-75%) compared to kyphoplasty (8-33%). This occurs due to distant leakage of cement into the venous plexus or retrograde migration into the aorta which leads to pulmonary cement emboli (PCE). PCE are usually asymptomatic; few patients are symptomatic; seen in 0.9% for vertebroplasty and 0.4% for kyphoplasty. PMMA has a prothrombotic effect, contributing to the thrombosis of the pulmonary vessels. Symptoms typically arise weeks to months after the procedure. In addition, it has been reported that rarely PCE can present with ARDS especially in patients with interstitial lung abnormalities. Methods We present a case of an 80-year-old female with a history of hypertension, diabetes mellitus and osteoporosis who underwent a kyphoplasty procedure with use of PMMA for spinal stenosis. Her post-operative course was complicated by multiple surgical revisions. She was noted to have pulmonary cement emboli five months post kyphoplasty and developed significant shortness of breath eight months post procedure. She ultimately developed cardio-pulmonary failure and was found to have bilateral pulmonary emboli and cement emboli at autopsy. Microscopic examination of the cement emboli documented round to oval vacuole-like cavities within and around blood vessels consistent with PMMA. Conclusion The histo-pathologic findings of cement emboli are not well documented in human beings compared to animal models. We attempt to highlight the gross and microscopic findings of PMMA cement emboli which is essential in the clinical-histo-pathologic correlation and characterization of pulmonary emboli at autopsy.