Background

Roux-en-Y bypass (RYGB) minimizes stomach size, food intake, and induces malnutrition, with known complications such as marginal ulceration, small bowel obstruction, and nutritional deficiencies. Hyperammonemia in this setting without precipitating factors is not a well-known occurrence.

Methods

We present a 41F with PMH of iron deficiency anemia treated with IV iron and bipolar disorder status post RYGB and recent duodenostomy and pyloroplasty for bleeding duodenal ulcers who presented with one month of rectal bleeding, progressive weakness, and confusion. She had been noncompliant with supplements and poor oral intake. CT demonstrated right lateral paraduodenal walled-off collections compatible with hematomas without active bleeding. The patient was persistently hypoglycemic and lethargic, and workup revealed an ammonia of 200umol/L. She was promptly started on lactulose and rifaximin via NG tube. With concern for metabolic encephalopathy, an EEG was done, consistent with epileptiform activity; and was started on levetiracetam. While awaiting IR drainage, she experienced acute mental status changes, leading to a code stroke and nonconvulsive status epilepticus confirmed on EEG. Plasma amino acid analysis later demonstrated elevated glutamine and low citrulline levels, suggestive of heterozygosity for ornithine transcarbamylase deficiency or a partial urea cycle disorder that developed post bypass. She was discharged on oral lactulose, rifaximin, and levetiracetam, and resumed her home medications.

Results

Genetic disorders can play critical roles in complications years after bariatric surgery. Liver biopsy, confirmatory genetic workup, and follow-up with bariatric surgery and Gl would help understand her metabolic state and other potential RYGB systematic effects.