title: The role of intra-arterial calcium stimulation test with hepatic venous sampling (IACS) in the management of occult insulinomas.
abstract: BACKGROUND
  Occult insulinomas remain a clinical challenge. Specifically designed protocols are necessary to aid detection and facilitate a focused pancreatic exploration.
  
  
  METHODS
  Seventeen non-multiple endocrine neoplasia (non-MEN) patients referred to this medical center in the past 10 years because of equivocal diagnosis, failure of previous operation or difficulty in localization for insulinomas were studied. A routine intra-arterial calcium stimulation test with venous sampling (IACS test) was done for lesion localization. An exploratory laparotomy with intraoperative ultrasound (IOUS) examinations was performed.
  
  
  RESULTS
  Preoperative imaging (sonography, high-resolution computed tomography scan, and magnetic resonance imaging) found six insulinomas, and IOUS found an additional six in the pancreatic regions; all were compatibly indicated by the IACS test. The remaining five patients with occult lesions by IOUS were treated by 40% (1) or 60-70% (4) distal pancreatectomies when insulin gradients were demonstrated on calcium stimulation to the splenic or to the superior mesenteric artery, respectively, and nesidioblastosis was found in each pathology examination. There were no complications related to the arterial stimulation and venous sampling (ASVS) test. No patient had recurrent hyperinsulinism, permanent morbidity, or mortality from surgery.
  
  
  CONCLUSIONS
  IACS test helps in the diagnosis of equivocal pancreatogenous hypoglycemia, indicating the pancreatic region of priority exploration and guiding a pancreatic resection.
authors: Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan.
authors: Ling-Ming
authors: LM
authors: Tseng
authors: Jui-Yu
authors: JY
authors: Chen
authors: Justin Ging-Shing
authors: JG
authors: Won
authors: Hsiao-Shan
authors: HS
authors: Tseng
authors: An-Han
authors: AH
authors: Yang
authors: Sine-E
authors: SE
authors: Wang
authors: Chen-Hsen
authors: CH
authors: Lee
mesh_terms: D000328:Adult; D000368:Aged; D002125:Calcium Gluconate / Q000008:administration & dosage; D005260:Female; D006503:Hepatic Veins; D006801:Humans; D007269:Injections, Intra-Arterial; D007328:Insulin / Q000097:blood*; D007340:Insulinoma / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D046768:Nesidioblastosis / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D018084:Ultrasonography, Interventional
chemical_list: D007328:Insulin; D002125:Calcium Gluconate