Treatment of portosystemic shunt-borne hepatic encephalopathy in a 97-year-old woman using balloon-occluded retrograde transvenous obliteration: A case report

Abstract

BACKGROUND

Hyperammonemia and hepatic encephalopathy are common in patients with portosystemic shunts. Surgical shunt occlusion has been standard treatment, although recently the less invasive balloon-occluded retrograde transvenous obliteration (B-RTO) has gained increasing attention. Thus far, there have been no reports on the treatment of portosystemic shunts with B-RTO in patients aged over 90 years. In this study, we present a case of hepatic encephalopathy caused by shunting of the left common iliac and inferior mesenteric veins, successfully treated with B-RTO.

CASE SUMMARY

A 97-year-old woman with no history of liver disease was admitted to our hospital because of disturbance of consciousness. She had no jaundice, spider angioma, palmar erythema, hepatosplenomegaly, or asterixis. Her blood tests showed hyperammonemia, and abdominal contrast-enhanced computed tomography revealed a portosystemic shunt running between the left common iliac vein and the inferior mesenteric vein. She was diagnosed with hepatic encephalopathy secondary to a portosystemic shunt. The patient did not improve with conservative treatment: Lactulose, rifaximin, and a low-protein diet. B-RTO was performed, which resulted in shunt closure and improvement in hyperammonemia and disturbance of consciousness. Moreover, there was no abdominal pain or elevated levels of liver enzymes due to complications. The patient was discharged without further consciousness disturbance.

CONCLUSION

Portosystemic shunt-borne hepatic encephalopathy must be considered in the differential diagnosis for consciousness disturbance, including abnormal behavior and speech.

Key Words: Hepatic encephalopathy, Hyperammonemia, Portosystemic shunt, Balloon-occluded retrograde transvenous obliteration, Elderly, Case report

Core Tip: Hyperammonemia and hepatic encephalopathy are common with portosystemic shunts. In this case, hepatic encephalopathy caused by shunting of the left common iliac and inferior mesenteric veins was successfully treated with balloon-occluded retrograde transvenous obliteration (B-RTO). A 97-year-old woman was diagnosed with hepatic encephalopathy secondary to a portosystemic shunt. The patient did not improve with conservative treatment: Lactulose, rifaximin, and a low-protein diet. B-RTO was performed, resulting in shunt closure and improvement in hyperammonemia and disturbance of consciousness. The patient was discharged without further consciousness disturbance.Portosystemic shunt-borne hepatic encephalopathy must be considered in the differential diagnosis for consciousness disturbance, including abnormal behavior and speech.

INTRODUCTION

Hepatic encephalopathy is defined as impaired brain function caused by liver insufficiency and/or portosystemic shunt[1]. Portosystemic shunts are known to cause hyperammonemia without liver dysfunction[2]. A portosystemic shunt is a condition in which portal blood flows directly into the systemic circulatory system. In such a condition, ammonia produced in the digestive tract is not metabolized in the liver, resulting in hyperammonemia and hepatic encephalopathy. Treatment methods include medical therapy, surgical shunt occlusion, and shunt embolization with interventional radiology (IVR)[2]. Surgical shunt occlusion or IVR is the treatment of choice when there is no improvement with medical treatment, or when complete cure is desired. In recent years, balloon-occluded retrograde transvenous obliteration (B-RTO) has attracted attention owing to its less invasive nature. However, thus far, there have been no reports of B-RTO treatment for cases of portosystemic shunts in very elderly patients, i.e., those aged above 90 years.

In this study, we report a case of hepatic encephalopathy caused by shunting of the left common iliac and inferior mesenteric veins in a 97-year-old patient whose condition improved after B-RTO treatment.

CASE PRESENTATION

Chief complaints

A 97-year-old Japanese woman exhibited abnormal behavior and disorganized speech for 10 d before admission.

History of present illness

Ten days prior to admission, the patient was agitated and spoke incomprehensible words to a neighbor. Her family met her 6 d prior to admission but noticed no unusual behavior or speech. Four days prior to admission, she exhibited strange behavior, saying that she did not know how to eat eggs and walking out with an egg clutched in her hand. Two days prior to admission, she lost spontaneity and had urinary incontinence, which she normally does not have. On the day of admission, her speech was impaired, and her family admitted her to the emergency room of our hospital.

History of past illness

She had a medical history of cholecystectomy and distal gastrectomy for gastric cancer, with no history of liver disease or cognitive dysfunction.

Personal and family history

She did not take any medications or consume alcohol. She lived alone and had independent activities of daily living; her food intake and defecation status were unknown.

Physical examination

Upon examination, she was disorientated, only answered “yes” to questions, and could not follow directions. Her vital signs were as follows: Glasgow Coma Scale score, 13 (E4V4M5); blood pressure, 157/111 mmHg; body temperature, 36.6 °C; pulse rate, 100 beats/min; respiratory rate, 20 breaths/min; and oxygen saturation, 99% on ambient air. Physical examination revealed no jaundice, spider angioma, palmar erythema, hepatosplenomegaly, or asterixis.

Laboratory examinations

Blood test results showed elevated serum ammonia levels at 125 μg/dL (normal range: 12-66 μg/dL) (Table 1). Cerebrospinal fluid examination results were normal, and blood cultures were negative.

Table 1 Laboratory data on admission.

Parameter	Recorded value	Standard value
White blood cell count	8500/µL	3500-8500/µL
Hemoglobin	14.5 g/dL	12-16 g/dL
Platelet count	16.5 × 104/µL	12-28 × 104/µL
Prothrombin time	15.2 s	10-13 s
Prothrombin time	60.8%	70-130%
Activated partial thromboplastin time	30.8 s	25.3-37.6 s
C-reactive protein	0.1 mg/L	≤ 0.5 mg/dL
Total protein	7.1 g/dL	6.5-8.3 g/dL
Albumin	4.2 g/dL	3.8-5.3 g/dL
Total bilirubin	1.4 mg/dL	0.2-1.2 mg/dL
Aspartate aminotransferase	35 U/L	7-34 U/L
Alanine aminotransferase	22 U/L	4-43 U/L
Lactase dehydrogenase	299 U/L	119-229 U/L
Alkaline phosphatase	128 U/L	38-113 U/L
γ-Glutamyl transpeptidase	16 U/L	6-30 U/L
Blood urea nitrogen	24 mg/dL	8-20 mg/dL
Creatinine	0.66 mg/dL	≤ 0.80 mg/dL
Sodium	145 mEq/L	139-146 mEq/L
Potassium	4.1 mEq/L	3.7-4.8 mEq/L
Chloride	109 mEq/L	101-109 mEq/L
Calcium	9.3 mg/dL	8.6-10.2 mg/dL
Glucose	102 mg/dL	70-109 mg/dL
TSH	1.06 μIU/mL	0.35-4.94 μIU/mL
Free T4	1.24 ng/dL	0.70-1.48 ng/dL
Cortisol	20.8 μg/dL	5.6-21.3 μg/dL
Vitamin B1	3.0 μg/dL	2.6-5.8 μg/dL
Ammonia	125 μg/dL	12-66 μg/dL
HBs-Ag	(-)
HCV-Ab	(-)

TSH: Thyroid-stimulating hormone; HBs-Ag: Hepatitis B virus surface antigen; HCV-Ab: Hepatitis C virus antibody.

Imaging examinations

Computed tomography (CT) of the head and magnetic resonance imaging showed no abnormalities.

FURTHER DIAGNOSTIC WORK-UP

On day 2 after admission, her serum ammonia levels were further elevated to 251 μg/dL and electroencephalography showed triphasic waves. On day 3, an abdominal contrast-enhanced CT scan revealed shunting between the left common iliac vein and the inferior mesenteric vein (Figure 1).

Figure 1 Abdominal computed tomography scan with contrast enhancement. A-C: Images showing a portosystemic shunt (orange arrow) running between the left common iliac vein (white arrow) and the inferior mesenteric vein (arrowhead).

FINAL DIAGNOSIS

Based on the extent of hyperammonemia and abdominal contrast-enhanced CT findings, a diagnosis of hepatic encephalopathy due to an extrahepatic portosystemic shunt was made.

TREATMENT

As conservative therapy, 39 g/d oral lactulose was started on day 4, and 1200 mg/d oral rifaximin and a low-protein diet were started on day 13. Her serum ammonia levels decreased to 80 μg/dL on day 14. However, there was little improvement in the patient’s level of consciousness. Therefore, B-RTO was performed under local anesthesia on day 20, and coils were placed in the shunts between the left common iliac vein and the inferior mesenteric vein (Figure 2). On day 21, contrast-enhanced CT confirmed no coil displacement, and shunt closure was achieved. By contrast, mild edematous changes were observed in the descending and sigmoid colons. Moreover, there was a partial thrombus in the inferior mesenteric vein; however, anticoagulants were not administered because of the patient's advanced age. We followed the patient carefully, noting abdominal pain and elevated liver enzymes.

Figure 2 Angiography images before and after embolization. A: A balloon catheter is advanced into the portosystemic shunt through the left femoral vein; B: The shunt is filled with the coil; C: The shunt is completely obliterated.

OUTCOME AND FOLLOW-UP

Her level of consciousness improved on day 21 (the day after B-RTO). Her serum ammonia levels were 21 μg/dL on day 28 and remained within the normal range throughout subsequent hospitalizations. There was no abdominal pain or elevated levels of liver enzymes due to complications. The patient was discharged on day 65 without any further disturbance of consciousness.

DISCUSSION

We report the case of a 97-year-old patient with hepatic encephalopathy due to shunting of the left common iliac and inferior mesenteric veins. To the best of our knowledge, this is the first case in which B-RTO was performed for a portosystemic shunt in a very elderly patient aged above 90 years.

On the basis of physical examination, hematology, and imaging findings, this case had no liver dysfunction or cirrhosis. The imaging findings showed shunting of the left common iliac vein and the inferior mesenteric vein, suggesting that the portosystemic shunt was the cause of hepatic encephalopathy. Portosystemic shunts are classified according to their location as type I (intrahepatic), type II (intrahepatic and extrahepatic), type III (extrahepatic), type IV (extrahepatic, portal hypertension), and type V (extrahepatic, absence of the portal vein)[2]. A type III (extrahepatic) portosystemic shunt, to which this case belongs, is the most frequent, accounting for 48.9% of all types, with an average age of onset of 57.4 years[2]. There are congenital and acquired causes of this type of shunt formation, with congenital causes being malformations or retained embryonal vascular vessels and the acquired causes being complications related to abdominal surgery[2]. The patient in this case had a history of cholecystectomy and distal gastrectomy, which may have resulted in the formation of an acquired shunt; however, the cause was difficult to determine because of the lack of comparative images from the past.

Surgical shunt occlusion is the curative treatment for portosystemic shunts; however, it is generally invasive and does not necessarily provide good outcomes[1]. In our case, complications and prolonged hospitalization were concerning. In such cases, IVR is an alternative treatment, and recently cases wherein patients were treated with B-RTO have been reported[3-6]. B-RTO is considered less invasive than surgical treatment, although it may cause complications, such as pleural effusion, ascites, thrombosis, pulmonary embolism, and worsening of esophageal varices[2,7-9]. Anticoagulant administration to elderly patients is particularly challenging owing to the risk of bleeding, and indications should be carefully considered. To the best of our knowledge, the oldest patient who underwent B-RTO for a portosystemic shunt was 86 years old[5]. B-RTO has no age-related restrictions on its indications and does not require special treatment on account of patients’ advanced age[10]. Although this patient was 97 years old, she had no serious comorbidities and was able to perform her daily activities. Therefore, we thought that there was great merit in performing curative treatment and B-RTO.

Hepatic encephalopathy is one of the differential diagnoses of disturbance of consciousness, and it is common to measure serum ammonia levels when there is a history of liver disease or physical findings suggestive of liver dysfunction[11]. By contrast, shock, gastrointestinal bleeding, vesicorectal fistulas, drugs such as valproic acid, and obstructive urinary tract infections caused by urease-producing bacteria may lead to hyperammonemia, even in the absence of liver diseases[12,13]. Portosystemic shunts also cause hyperammonemia[14].

Although there was no history of liver disease or findings suggestive of liver dysfunction in this case, measurement of serum ammonia levels led to diagnosis and subsequent treatment.

CONCLUSION

This is the first report of B-RTO performed in a patient aged > 90 years with a portosystemic shunt. It is important to consider hepatic encephalopathy due to a portosystemic shunt as a differential diagnosis of disturbance of consciousness, including abnormal behavior and disorganized speech.