Novel therapy for non-cirrhotic hyperammonemia due to a spontaneous splenorenal shunt

Nonhepatic hyperammonemic encephalopathy following bariatric surgery: A systematic review

BACKGROUND

Nonhepatic Hyperammonemic encephalopathy (NHAE) following Bariatric Surgery (BS), mainly Roux-en-Y Gastric Bypass (RYGB) and Biliopancreatic Diversion (BPD) is a potentially devastating condition if not diagnosed and managed promptly.

METHODS

A literature review was performed using PRISMA guidelines. Eighteen studies and 3 conference abstracts with a total of 33 patients were included in this review.

RESULTS

Majority (28 patients, 84.8 %) had RYGB. Seven patients (21.2 %) had associated metabolic disorders. 60 % of patients presented with neurological symptoms or signs such as confusion, cognitive and/or psychomotor changes, and decreased reflexes. Two patients presented with status epilepticus. In 30 of the 33 patients an elevated serum ammonia levels was reported (90.9 %). The overall mortality was 39.3 %.

CONCLUSION

NHAE is a rare condition following bariatric surgery (in particular bypass procedures), carrying a high mortality rate. The signs and symptoms are predominantly neurological and may be mistaken for Wernicke's encephalopathy or other more common neurological conditions. Serum ammonia levels should be checked in those who present with these symptoms and signs. Prompt treatment might be life saving in patients with NHAE.

Hyperammonemia Encephalopathy due to Urea Cycle Disorder Precipitated by Gastrointestinal Bleed in the Setting of Prior Bariatric Surgery

The urea cycle is a metabolic pathway that excretes nitrogenous waste products from the body. Urea cycle disorders (UCDs) result from enzymatic deficiencies within this pathway, which can lead to life-threatening hyperammonemia. Gastric bypass-related hyperammonemia in patients who have undergone Roux-en-Y gastric bypass surgery has been previously reported. UCDs have been implicated as a cause of gastric bypass-related hyperammonemia. In this report, we present the case of a patient with a history of bariatric surgery who experienced severe hyperammonemia encephalopathy triggered by a gastrointestinal bleed due to an undiagnosed UCD.

Multimodality ultrasound assessment of the spleen: Normal appearances and emergency abnormalities

This paper summarizes the main splenic emergencies and their ultrasonographic findings to orient appropriate patient management. US requires minimal preparation time and allows to examine the parenchyma and to detect intraperitoneal fluid collections, which may be indirect evidence of solid organ injuries. In this paper, we analyze the role of B-mode, Doppler and Contrast-Enhanced Ultrasound in the diagnosis of splenic emergencies, with a particular focus on splenic infarction, infection, traumatic injuries and vascular splenic anomalies.

Cognitive Impairement in Non-Cirrhotic Portal Hypertension: Highlights on Physiopathology, Diagnosis and Management

Hepatic encephalopathy (HE) is one of the most frequent complications of cirrhosis. Several studies and case reports have shown that cognitive impairment may also be a tangible complication of portal hypertension secondary to chronic portal vein thrombosis and to porto-sinusoidal vascular disease (PSVD). In these conditions, representing the main causes of non-cirrhotic portal hypertension (NCPH) in the Western world, both overt and minimal/covert HE occurs in a non-neglectable proportion of patients, even lower than in cirrhosis, and it is mainly sustained by the presence of large porto-systemic shunt. In these patients, the liver function is usually preserved or only mildly altered, and the development of porto-systemic shunt is either spontaneous or iatrogenically frequent; HE is an example of type-B HE. To date, in the absence of strong evidence and large cooperative studies, for the diagnosis and the management of HE in NCPH, the same approach used for HE occurring in cirrhosis is applied. The aim of this paper is to provide an overview of type B hepatic encephalopathy, focusing on its pathophysiology, diagnostic tools and management in patients affected by porto-sinusoidal vascular disease and chronic portal vein thrombosis.

Russian Consensus “Hyperammonemia in Adults” (Version 2021)

Justification Given the large number of reports on the peculiarities of liver lesions during the Sars-Cov-2 infection [1], a team of experts who participated in the 23rd Congress of the Scientific Society of Gastroenterologists of Russia and 15 National Congress of Therapists of November 19, 2020 decided to make additions to the Russian Consensus of “Hyperammonemia in Adults” published early 2020 [2, 3].

Recurrent noncirrhotic hyperammonemia causing acute metabolic encephalopathy in a patient with a continent ileocecal pouch: a case report

Introduction

Acute encephalopathy, while a common presentation in the emergency department, is typically caused by a variety of metabolic, vascular, infectious, structural, or psychiatric etiologies. Among metabolic causes, hyperammonemia is relatively common and typically occurs in the setting of cirrhosis or liver dysfunction. However, noncirrhotic hyperammonemia is a rare occurrence and poses unique challenges for clinicians.

Case presentation

Here we report a rare case of a 50-year-old Caucasian female with history of bladder cancer status post chemotherapy, radical cystectomy, and ileocecal diversion who presented to the emergency department with severe altered mental status, combativeness, and a 3-day history of decreased urine output. Her laboratory tests were notable for hyperammonemia up to 289 μmol/L, hypokalemia, and hyperchloremic nonanion gap metabolic acidosis; her liver function tests were normal. Urine cultures were positive for Enterococcus faecium. Computed tomography imaging showed an intact ileoceal urinary diversion with chronic ileolithiasis. Upon administration of appropriate antibiotics, lactulose, and potassium citrate, she experienced rapid resolution of her encephalopathy and a significant reduction in hyperammonemia. Her hyperchloremic metabolic acidosis persisted, but her hypokalemia had resolved.

Conclusion

This case is an example of one of the unique consequences of urinary diversions. Urothelial tissue is typically impermeable to urinary solutes. However, when bowel segments are used, abnormal absorption of solutes occurs, including exchange of urinary chloride for serum bicarbonate, leading to a persistent hyperchloremic nonanion gap metabolic acidosis. In addition, overproduction of ammonia from urea-producing organisms can lead to abnormal absorption into the blood and subsequent oversaturation of hepatic metabolic capacity with consequent hyperammonemic encephalopathy. Although this is a rare case, prompt identification and treatment of these metabolic abnormalities is critical to prevent severe central nervous system complications such as altered mental status, coma, and even death in patients with urinary diversions.

Non-cirrhotic Extra-Hepatic Porto-Systemic Shunt Causing Adult-Onset Encephalopathy Treated with Endovascular Closure

INTRODUCTION

Encephalopathy secondary to hyperammonemia due to Congenital Extra-hepatic Porto-systemic shunt (CEPS) in the absence of liver cirrhosis is an exceptionally unusual condition. We describe the case of a 54-year-old woman admitted to the Emergency Department complaining of recurrent episodes of confusion and worsening cognitive impairment. At admission, the patient displayed slowing cognitive-motor skills with marked static ataxia and impaired gait. Hyperammonemia was detected in the serum. An abdominal computed tomography (CT) excluded portal hypertension and liver cirrhosis, detecting a congenital extra-hepatic porto-systemic shunt which is a highly unusual vascular malformation. The patient was treated by interventional radiologists with a successful endovascular closure.

AREAS COVERED

We have performed a review of the last three decades of the literature, starting from the introduction of CT scanning in common clinical practice. Eighteen studies (case reports) described 29 patients with encephalopathy secondary to hyperammonemia due to CEPS in the absence of liver cirrhosis: They underwent treatment similar to our case report of CEPS.

EXPERT COMMENTARY

Encephalopathy secondary to hyperammonemia in the absence of hepatic dysfunction is an important diagnostic dilemma to many clinicians. An interventional radiologic approach is currently preferred.

Hepatic encephalopathy secondary to a splenorenal shunt that manifested a long time after a liver transplantation

Splenorenal shunts are a rare cause of hyperammonemia and hepatic encephalopathy in the absence of cirrhosis. We report the case of a woman, who presented hepatic encephalopathy, with a normal functioning graft, after 14 years of liver transplantation, confirmed by liver biopsy.

Disabling portosystemic encephalopathy in a non-cirrhotic patient: Successful endovascular treatment of a giant inferior mesenteric-caval shunt via the left internal iliac vein

Hepatic encephalopathy is suspected in non-cirrhotic cases of encephalopathy because the symptoms are accompanied by hyperammonaemia. Some cases have been misdiagnosed as psychiatric diseases and consequently patients hospitalized in psychiatric institutions or geriatric facilities. Therefore, the importance of accurate diagnosis of this disease should be strongly emphasized. A 68-year-old female patient presented to the Emergency Room with confusion, lethargy, nausea and vomiting. Examination disclosed normal vital signs. Neurological examination revealed a minimally responsive woman without apparent focal deficits and normal reflexes. She had no history of hematologic disorders or alcohol abuse. Her brain TC did not demonstrate any intracranial abnormalities and electroencephalography did not reveal any subclinical epileptiform discharges. Her ammonia level was > 400 mg/dL (reference range < 75 mg/dL) while hepatitis viral markers were negative. The patient was started on lactulose, rifaximin and low-protein diet. On the basis of the doppler ultrasound and abdomen computed tomography angiography findings, the decision was made to attempt portal venography which confirmed the presence of a giant portal-systemic venous shunt. Therefore, mechanic obliteration of shunt by interventional radiology was performed. As a consequence, mesenteric venous blood returned to hepatopetally flow into the liver, metabolic detoxification of ammonia increased and hepatic encephalopathy subsided. It is crucial that physicians immediately recognize the presence of non-cirrhotic encephalopathy, in view of the potential therapeutic resolution after accurate diagnosis and appropriate treatments.

Late presentation of fatal hyperammonemic encephalopathy after Roux-en-Y gastric bypass

Worldwide, there have been <25 reported cases of hyperammonemic encephalopathy associated with Roux-en-Y gastric bypass surgery in the absence of cirrhosis. We describe a 42-year-old woman who presented with subacute but progressive neurological decline late in her postoperative course, which deteriorated despite multiple conservative and aggressive measures, including hemodialysis, in an attempt to reduce measured plasma ammonia levels. This syndrome of hyperammonemic encephalopathy represents a serious, underrecognized, and potentially treatable complication after Roux-en-Y gastric bypass.

Vascular Diseases of the Spleen: A Review

Vascular diseases of the spleen are relatively uncommon in the clinical practice. However, the reported incidence has been progressively increasing, probably due to advances in the imaging modalities used to detect them. This disease condition often presents with non-specific clinical manifestations, but can be associated with significant morbidity and mortality. This review article aims to provide updated clinical information on the different vascular diseases of the splenic vasculature-splenic vein thrombosis, splenic vein aneurysm, splenic artery aneurysm, splenic arteriovenous fistula, and spontaneous splenorenal shunt-in order to aid clinicians in early diagnosis and management.

Noncirrhotic hyperammonemia causing relapsing altered mental status

Hyperammonemia is a recognized cause of encephalopathy. However, it is commonly seen in patients with liver disease. The clinical entity of noncirrhotic hyperammonemia is now being increasingly recognized. We report a man who presented to our hospital with relapsing altered mental status later diagnosed as noncirrhotic hyperammonemia.

Hyperammonemic syndrome after Roux-en-Y gastric bypass

OBJECTIVE

Hyperammonemic encephalopathy is an uncommon but severe complication of the Roux-en-Y gastric bypass surgery for obesity. Mechanisms underlying this complication are incompletely understood, resulting in delayed recognition and management. This study evaluated common laboratory findings and possible etiology of hyperammonemic encephalopathy after successful Roux-en-Y gastric bypass surgery.

METHODS

A retrospective review of 20 patients identified through our own clinical practice was conducted, with the addition of similar cases from other institutions identified through the review of literature.

RESULTS

Patients presenting with hyperammonemic encephalopathy after Roux-en-Y gastric bypass surgery presented with overlapping clinical and laboratory findings. Common features included: (1) weight loss following successful Roux-en-Y gastric bypass for obesity; (2) hyperammonemic encephalopathy accompanied by elevated plasma glutamine levels; (3) absence of cirrhosis; (4) hypoalbuminemia; and (5) low plasma zinc levels. The mortality rate was 50%. Ninety-five percent of patients were women. Three patients were diagnosed with proximal urea cycle disorders. One patient experienced improvement in the hyperammonemia after surgical correction of spontaneous splenorenal shunt.

CONCLUSIONS

Hyperammonemic encephalopathy after Roux-en-Y gastric bypass surgery is a newly recognized, potentially fatal syndrome with diverse pathophysiologic mechanisms encompassing genetic and nongenetic causes.