Incidence and clinical significance of hyperamylasemia after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions: a prospective and controlled study.

BACKGROUND AND STUDY AIM: Acute pancreatitis as a complication of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic lesions is rarely observed. However, there is little information on the incidence of hyperamylasemia after EUS-FNA of the pancreas and its clinical significance. This study aimed to supply this lack of information.

PATIENTS AND METHODS: Patients who underwent EUS-FNA of a pancreatic lesion between October 2004 and October 2005 were studied prospectively. Exclusion criteria were: (i) platelet count under 50,000/mm (3) and/or prothrombin time < 50 %; (ii) performance of surgery, endoscopic retrograde cholangiopancreatography (ERCP), a percutaneous biopsy attempt, or another invasive procedure within 7 days before EUS-FNA; (iii) lack of informed consent. Serum amylase levels were determined before and 8 and 24 h after the procedure. Hyperamylasemia was defined by amylase levels above 104 UI/L (and higher than baseline levels) 8 h after the procedure. Acute pancreatitis was defined by upper abdominal pain (with or without nausea and/or vomiting) accompanied by elevation of serum amylase or lipase to at least twice baseline levels.

RESULTS: A total of 100 patients underwent EUS-FNA of a pancreatic lesion (58 men, 42 women; mean age 60 +/- 13 years). Eleven patients (11 %) showed hyperamylasemia 8 h after the puncture (298 +/- 293 UI/L, range 105 - 1044 UI/L), but only two of them developed acute mild pancreatitis after EUS-FNA. Hyperamylasemia was not related either to the type of lesion (cystic or solid) or to its location, the duration of the procedure, or the number of passes performed.

CONCLUSIONS: Pancreatitis after pancreatic EUS-FNA occurs in 2 % of patients, with some more cases of silent hyperamylasemia. This complication may have to be included in the information given to patients for their informed consent.