Modified Frey Technique for Treatment of Persistent Hyperinsulinemic Hyperglycemia Due to Nesidioblastosis: A Case Report

<i>Introduction: </i>Hypoglycemia in non-diabetic individuals is rare but represents a significant diagnostic and therapeutic challenge. One of its uncommon causes is Nesidioblastosis, characterized by diffuse or focal hyperplasia of pancreatic β cells, leading to endogenous hyperinsulinemic hypoglycemia. Although more frequent in neonates, cases in adults have been increasingly recognized, especially in the absence of insulinoma. In adults, this condition presents with β cell hypertrophy, enlarged islets, and hyperchromatic nuclei, with postprandial hypoglycemia being its main symptom. This article aims to demonstrate a technical modification for preserving the duodenum and bile duct in the treatment of a patient with Nesidioblastosis who underwent several surgical treatments without results. <i>Case Presentation:</i> This article reports the case of a man with intermittent symptomatic hypoglycemia for two years, who required multiple surgical interventions for effective control of the disease. Was done a technical modification for preserving the duodenum and bile duct in the treatment of a patient with Nesidioblastosis who underwent several surgical treatments without results. Given the current clinical picture, in which a pancreaticoduodenectomy with total resection of the remaining pancreas would be indicated due to hypoglycemia refractory to several types of clinical and surgical treatments, we decided to perform the Frey technique for this case, thus preserving a small segment of the pancreas together with the duodenal arch and thus preserving the main bile duct. <i>Discussion and Conclusion:</i> Preoperative diagnosis is challenging due to the nonspecificity of symptoms and the absence of specific functional tests and is usually confirmed by histopathological examination after surgery. Initial treatment involves nutritional modifications and the use of medications. However, moderate to severe and refractory cases require surgical intervention. Partial or subtotal pancreatectomy is effective, although some cases require multiple surgeries. In the reported case, the Frey technique was successfully used, promoting effective glycemic control and minimizing gastrointestinal complications. Despite partial preservation of the pancreas, the patient developed postoperative diabetes, highlighting the importance of balancing effective removal of hyperfunctioning tissue and preservation of pancreatic function. It is concluded that surgical treatment as a last resort and using the technique described by Frey as a way to preserve the gastrointestinal tract and avoid total pancreatectomy with its serious repercussions on the patient's metabolism.