Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Obesity (Silver Spring). 2015 Apr;23(4):746-9. doi: 10.1002/oby.21037. Epub 2015 Mar 7.
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.
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.
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.
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.
高氨血症性脑病是肥胖症患者 Roux-en-Y 胃旁路手术后一种不常见但严重的并发症。该并发症的发病机制尚不完全清楚，导致其识别和处理延迟。本研究评估了 Roux-en-Y 胃旁路手术后成功后高氨血症性脑病的常见实验室发现和可能的病因。
通过我们自己的临床实践，对 20 例患者进行了回顾性研究，并通过文献复习，对其他机构的类似病例进行了补充。
Roux-en-Y 胃旁路手术后出现高氨血症性脑病的患者具有重叠的临床和实验室发现。共同特征包括：（1）肥胖症 Roux-en-Y 胃旁路手术后成功减肥；（2）高氨血症性脑病伴有血浆谷氨酰胺水平升高；（3）无肝硬化；（4）低白蛋白血症；（5）低血浆锌水平。死亡率为 50%。95%的患者为女性。3 例患者被诊断为近端尿素循环障碍。1 例患者在自发性脾肾分流手术矫正后，高氨血症得到改善。
Roux-en-Y 胃旁路手术后的高氨血症性脑病是一种新认识的、潜在致命的综合征，其病理生理机制多种多样，包括遗传和非遗传原因。
