Stroke During Hip Surgery

J INVASIVE CARDIOL 2021;33(2):E143-E144.

Key words: fat embolism, hip surgery, stroke

A 62-year-old woman remained unconscious immediately after surgery under general anesthesia for hip fracture (Figure 1A) that resulted from an accidental fall. Medical history included heart failure with moderately reduced left ventricular function. The patient reported no previous neurological symptoms. There were no abnormal intraoperative findings, particularly no decrease of oxygen saturation, no circulatory instability, normal heart rate, and no drop in arterial blood pressure. On physical examination, heart rate was regular at 72 beats/min and blood pressure was 129/82 mm Hg. There were no clinical signs of pulmonary embolism and no further testing was performed. She had no fever, but severely impaired cognition and inappropriate response to auditory and noxious stimuli. Bilateral Babinski signs were positive and tone of upper and lower extremities was unremarkable. Neck stiffness was absent and pupillary light reflex and corneal reflex were preserved. Laboratory findings including glucose concentration and electrolytes were in the normal ranges. An electrocardiogram showed regular sinus rhythm and no abnormalities.

Computed tomography (CT) of the brain without contrast medium revealed small frontal and periventricular white matter lesions and CT angiography was unremarkable. Brain magnetic resonance imaging demonstrated scattered spot lesions with restricted diffusion on diffusion-weighted imaging (DWI) sequences, hyperintensity on T2-weighted imaging, and microhemorrhages on susceptibility-weighted imaging, suggestive of fat embolism (Figure 1B).

Transesophageal echocardiogram revealed a moderately sized persistent foramen ovale (PFO), and agitated saline solution contrast echocardiography and Color-Doppler imaging during Valsalva maneuver confirmed a right-to-left shunt (Figure 1C; arrow).

We performed close monitoring and careful observation including conservative post-stroke treatment. Four weeks after surgery, the patient was discharged with remaining dysarthria and mild cognitive impairment. The patient is currently scheduled for PFO closure.

During hip replacement, acetabular and femur bone preparation may cause bone marrow extravasation. Paradoxical fat embolism occurs when emboli pass from the pulmonary to the systemic circulation by either a PFO or pulmonary capillaries. Impaired consciousness in the immediate postoperative period of orthopedic surgery frequently results from hypovolemia, anemia, or residual anesthesia. A high index of suspicion is required to consider the possibility of paradoxical fat embolism.

From the ¹Department of Cardiology and Intensive Care, St. Josef Hospital Braunau, Braunau, Austria; and ²Department of Cardiology, Kepler University of Medicine Linz, Linz, Austria.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

The authors report that patient consent was provided for publication of the images used herein.

Manuscript accepted March 31, 2020.

Address for correspondence: Johann Auer, MD, FESC, FACC, FAHA, FSCAI, Department of Cardiology and Intensive Care, “St Josef “ Hospital, Braunau, Austria. Email: johann.auer@khbr.at