A rare cause of perioperative stroke
A 67-year-old lady with a long-standing history of dyspnea on exertion and cerebellar abscess 8 years back that was managed conservatively underwent right total knee replacement under spinal anesthesia for severe osteoarthrosis from a nearby center. She had no prior history of vascular risk factors or ischemic heart disease. The patient was well in the immediate postoperative period. On the second postoperative day, she was noted to have acute onset weakness of the left leg followed by right upper limb and was shifted to our center for further management.\nOn arrival, the patient was restless, drowsy with tachypnea and was having grade 0 power in the right upper limb and left lower limb with bipyramidal signs, without features of intracranial hypertension, cranial nerve dysfunction, fever or meningeal signs. She was evaluated with magnetic resonance imaging, which showed fluid attenuation inversion recovery (FLAIR) hyperintensities in the anterior and posterior circulation territories, some showing restricted diffusion suggestive of infarcts of varying ages [Figure –]. Vessel imaging was normal. Her chest radiograph showed multiple shadows, which was initially interpreted as secondary to aspiration []. Arterial blood gas analysis showed type 1 respiratory failure (on O2by mask 6l/mt-p O242.7, p CO231 hco3 26, p H 7.54). She was intubated and ventilated in view of altered sensorium, respiratory distress and hypoxemia.\nPresentation in the early postoperative period following orthopedic surgery with focal neurological deficits, multiple cerebral infarcts and respiratory failure made us consider pulmonary embolism and postoperative stroke as the first possibility. There were no features to suggest fat embolism. Lower limb venous Doppler did not show any deep venous system thrombosis; however, the pelvic veins could not be studied. Her cardiac evaluation, including transthoracic echo and 24-h ECG, were normal.\nThe patient showed improvement in sensorium and weakness by the next week, but was having persistent hypoxemia (on ventilator SIMV, PS 12, PEEP 5, Fi O250% p O253, p CO226, Ph 7.45, with normal lung compliance) and had a few bouts of hemoptysis. A review of her chest radiographs showed nodular opacities in both lung fields appearing contiguous with pulmonary artery shadows, raising a suspicion of PAVF []. Therefore, she underwent computed tomography (CT)-pulmonary angiogram, which showed multiple high-flow PAVF – a total of six in number – with arterial feeders from the right superior, middle and inferior as well as the left inferior pulmonary artery thus explaining her persisting hypoxemia and route for multiple cerebral embolism []. She was not cooperative for transesophageal echo, but we performed a transcranial Doppler with agitated saline contrast, which showed high-intensity transient signals in the middle cerebral artery suggesting the presence of a right to left shunt. There were no other clinical features or family history of hereditary hemorrhagic telengectasia (HHT). However, genetic studies could not be done.\nSubsequently, the patient was extubated and initiated on rehabilitation. She made a good recovery of her motor power (mRS = 2 at discharge) and is doing well on follow-up.