Lipiodol brain embolism through right inferior phrenic artery-pulmonary vein shunt after transcatheter arterial chemoembolization

Abstract

Introduction

Transcatheter arterial chemoembolization (TACE) has been widely used to treat patients with an unresectable hepatocellular carcinoma (HCC).1 Lipiodol brain embolism, a type of non-target embolization, is rarely reported; it is known as cerebral lipiodol embolism (CLE).2 Here we report a case of CLE after TACE and reveal the associated clinical symptoms, imaging findings, as well as review of the previous literature.

Case Report

A 71-year-old male visited the hospital for his 21st TACE and was referred to our interventional radiology department. The patient had a history of heavy alcoholism over the past 50 years (1 bottle of Soju daily) and was diagnosed with alcoholic liver cirrhosis. During the follow-up for his liver cirrhosis, multiple HCCs were detected via ultrasound. He received three rounds of radiation therapy and 20 rounds of TACE. At the time of admission, the laboratory results were as follows: HBsAg, negative; anti-HBs Ab, positive; total bilirubin, 1.1 mg/dL; aspartate aminotransfer-ase/alanine aminotransferase (AST/ALT), 35/19 IU/L; prothrombin time (PT), 76.3%; alpha fetoprotein (AFP), 530.1 ng/mL (normal range, 0.0–7.5 ng/mL). The dynamic abdominal computed tomography (CT) revealed several enhanced masses at segments 6 and 8, which were suggestive of HCC (Fig. 1A). On the patient’s 2nd day of hospitalization, the 21st TACE was performed. On the celiac angiography, several tumor stains, which were supplied by the reconstructed right hepatic artery through the intrahepatic collateral of the left hepatic artery, were observed in segment 6. After selecting the left hepatic artery, 100 mg cisplatin (Il-Dong, Seoul, Korea) was continuously infused for 15 minutes. Next, the feeding artery was selected and embolized with an emulsion of cisplatin in iodized oil (Lipiodol; Laboratoire Andre Cuerbet, Aulnaysous Bois, France). Next, right inferior phrenic artery (IPA) angiography was also performed. On the angiography, several stained tumors were shown, which were supplied from both ascending and descending branches of the right IPA (Fig. 1B). The right IPA was embolized with the lipiodol–cisplatin mixture and gelatin sponge particles (350–550 μm in diameter, Cali-Gel; Alicon, Zhejiang, China).

Figure 1

A 71-year-old man with multiple hepatocellular carcinomas (HCCs). (A) The computed tomography (CT) scan revealed HCC in the liver dome with other HCCs, which was not revealed on the present ...

On the day after TACE, the patient fell off the bed and suffered a contusion on his face and head. At that time, the patient exhibited no symptoms, and his vital signs were also stable; however, two hours later, the patient complained of right facial palsy and motor weakness of the right extremities. On the physical examination, the muscle strength of the right upper and lower limbs were identified as grade 1, and the patient occasionally felt drowsy. Thus, a brain CT was performed to exclude the possibility of an intracranial hemorrhage. The brain CT images revealed no intracranial hemorrhage but diffuse and bilateral cortical high attenuated lesions in the cerebrum and cerebellum, suggesting the presence of lipiodol depositions owing to a history of TACE (Fig. 2A). A brain magnetic resonance imaging (MRI) with diffusion was also serially performed and revealed multifocal diffusion-restricted lesions and high signal intensities in the bilateral cerebral cortices, bilateral deep and periventricular white matter, and cerebellum on the diffusion weighted (DWI) and T2-weighted and fluid-attenuated inversion recovery (FLAIR) images (Fig. 2B, 2C). Finally, the patient was diagnosed with an acute cerebral and cerebellar infarction by a lipiodol embolism. Anticoagulants were not applied due to bleeding risk secondary to thrombocytopenia (platelets, 71 × 10³/μL).

Figure 2

(A) Non-enhanced computed tomography image exhibiting multiple lipiodol depositions, bilaterally. The magnetic resonance imaging revealed diffusion-restricted lesions on the diffusion weighted (B) and multifocal hyperintensities in the cerebrum and cerebellum ...

Three days later, after the patient experienced weakness of his right limbs and a change in the mental state, a follow-up MRI was performed. The MRI showed a greater extension of the bilateral high signal intensities in the cerebrum and cerebellum on T2 and FLAIR images (Fig. 2D). Despite these radiographic changes, his mental alertness and motor strength of the right lower limb improved (Grade 4 for muscle strength). However, the motor strength of the right upper limb did not recover (Grade 1 for muscle strength). The patient then underwent electroencephalography (EEG) and transthoracic echocardiography (TTE). Although the TTE results were normal, the EEG results exhibited a partial seizure disorder and moderate diffuse cerebral dysfunction. Thus, the patient was treated with oral antiepileptic drugs twice per day.

On th 9th day of hospitalization, was more recovered on the follow-up EEG On the 12th day of hospitalization, the patient’s motor strength of the right upper extremity substantially improved (Grade 4 for muscle strength). He could be discharged and planned to visit the local hospital for additional rehabilitation; however, the patient had to be maintained on anti-epileptic drugs and aspirin once per day.

Discussion

TACE is an accepted palliative treatment for unresectable HCC.1 Despite the effort to minimize the complications associated with TACE, various adverse effects occur, including hepatic failure, liver infarction or abscess, cholecystitis, pulmonary embolism, and an iatrogenic dissection. In particular, CLE is an unusual complication that has occasionally been reported.2

In patients with CLE, the symptoms are nonspecific. The severity and type of symptoms may depend on the site of lipiodol deposition.3 By the report of Wu et al,4 the symptoms of CLE included visual loss, headache, weakness of motor strength, and change in the mental state. In our case, the patient experienced right facial palsy and motor weakness in both the right upper and lower limbs. The patient also exhibited a drowsy mental state.

The mechanisms underlying CLE were unclear in this case. Previous case reports suggest the following potential mechanisms: (1) intracardiac right-to-left shunt of the heart, (2) the shunt between the pulmonary vein and hepatic artery/IPA, (3) hepatic artery/IPA–intrapulmonary arteriovenous shunt, and (4) microemboli through the sinusoids of the liver to the pulmonary capillaries, which were induced by an increased lipiodol dose.3,5–8 According to the study by Choi et al,3 CLE could be occured by communication between the right IPA and pulmonary vein via inflammatory pleura. In our case, the dynamic abdominal CT scan also showed inflammation of right lower lobe and pleura (Fig. 1A). So, these inflammation could be one of causes, inducing communication between right IPA and pulmonary vein. However, they could not demonstrate a vascular shunt on the digital subtraction angiography (DSA) or echocardiography. In the present case, at the time of performing the procedure, the right IPA–pulmonary vein shunt was not recognized due to the incorporation of respiration during DSA. After the acute stroke event, we carefully and retrospectively reviewed the records and found the right IPA–pulmonary vein shunt during the right IPA angiography (Fig. 1B). Moreover, the shunt was not shown in the right IPA angiography during the previous TACE. Therefore, although there was no congenital IPA–pulmonary vein shunt, the repeated administration of TACE and/or the aggravation of pleural inflammation could induce an acquired right IPA–pulmonary vein shunt and the repeated TACE and/or pleural inflammation could be a risk factor for the development of CLE.

According to previous reports, the imaging findings of the CLE were similar on both the CT and MRI. In addition, Kim et al9 reported multiple hyperdense lesions along the bilateral frontal gyri and bilateral parietal subcortical white matter on a non-enhanced brain CT. In the same patient, the DWI revealed an acute infarction in the cerebrum and cerebellum. Karapanayiotides et al8 and Zach et al10 also showed similar imaging findings. A non-enhanced brain CT revealed extensive lipiodol deposition bilaterally in the brain, and on the MRI, there was an acute infarction in the cortices as well as deep and subcortical white matter of the cerebrum and cerebellum. The following MRI showed an increase in previous cerebral high signal intensity on the FLAIR images, although the patient’s symptoms had improved.

Majority of previous reports have shown good prognosis of CLE following TACE. The reported patients were usually spontaneously recovered by conservative therapy. They gradually improved within several days to weeks. Some patients exhibited normalized brain parenchyma on CT, whereas some cases showed a fatal condition following CLE.10 Some of these fatalities were due to multi-organ failure or respiratory failure. In our case, the patient was administered anticoagulants for several days to resolve the acute stroke; however, he was primarily administered supportive therapy. Although the patient initially presented with serious symptoms associated with an acute stroke and epilepsy on the EEG, the symptoms gradually recovered and the patient was finally discharged and planned to undergo rehabilitation at a local hospital.

CLE is a rare complication following TACE and exhibits a good prognosis in most patients based on our review of cases, including this case. However, this condition can induce irreversible sequelae or lead to a fatal outcome (e.g., multi-organ failure or respiratory failure). Thus, an intervention radiologist should be aware of this complication and carefully evaluate a vascular shunt before and during the procedure. During the actual procedure, if the patient exhibits symptoms associated with acute stroke, both CT and MRI are useful diagnostic tools for a lipiodol embolism. Moreover, conservative management could be helpful to treat patients with CLE.

Conflicts of Interest

No potential conflict of interest relevant to this article was reported.

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