Endocrine Surgery

 

Gastrinoma

  • Dx: Patients present with hypergastrinemia and severe recurrent peptic ulcer disease (Zollinger Ellison syndrome)
    • Rule out MEN I (parathyroid, pancrease, and pituitary tumors).
    • Fasting gastrin > 100 (> 500 is diagnostic).
    • Secretin stimulation test confirms (gastrin increases with gastrinoma).
    • Localization is done with CT, octreotide scan, IOUS, or duodenoscopy.
  • Tx: Management depends on localization (gastrinoma triangle is junction of cystic duct, the common bile duct, and D2/D3 junction inferiorly)
    • Duodenum gets enucleation (consider whipple if unable to enucleate)
    • Metastasis to liver gets debulking, PPI, somatostatin, and streptozotocin.
    • Non-localization gets duodenotomy, IOUS, consider acid reducing operation, and somatostatin.

Insulinoma

  • Dx: Patients present with Whipple's triad (hypoglycemia symptoms, hypoglycemia, and relief of symptoms with glucose).
    • Elevated insulin, low glucose, elevated C-terminal peptide.
    • Rule out MEN I
    • Differential of hypoglycemia includes cirrhosis, glycogen storage disease, large tumors.
    • Localization is done with CT ab/pelvis, octreotide scan, arteriogram, or IOUS.
  • Tx: Start with diazoxide or somatostatin until surgery. 
    • Surgical treatment in enucleation
    • If unable to localize, can do distal pancreatectomy and frozen section.
    • MEN I should have subtotal pancreatectomy

Adrenal Incidentaloma

  • Dx: These are discovered incidentally on CT scan for other reasons
    • Determine size and hounsfield units for likelyhood of malignancy.
      • Adenoma is  <4cm, <10 hounsfield, and fatty.
      • Carcinoma is >4cm, have necrosis, calcifications, and hemorrhage.
    • Start with biochemical evaluation:
      • 24hr urine cortisol
      • 24hr urine metanephrine, normetanephrine
      • Aldosterone/renin if HTN and hypokalemic (Abnormal ratio is > 20)
  • Tx: Managment depends on size and activity.
    • Biochemical activity requires resection.
    • Tumor < 4cm can watch
    • Tumor > 4cm needs excision
    • Laparoscopic adrenalectomy can be used for tumor < 6cm.
    • Anterior Adrenalectomy:
      • Laparotomy and survey abdomen.
      • Left side= take down splenic flexure
      • Right side= take down hepatic flexure, kocherize the duodenum, take down right triangular ligament.
      • Enter gerota's fascia, start cephalad, and dissect towards renal hilum.
      • Dissect between adrenal and pancreas/spleen (left) or liver (right).
      • Identify adrenal vein and ligate (left side renal vein, right side off posterior surface of IVC).
      • Continue dissection over renal capsule.
      • Remove retroperitoneal fat with the adrenal gland.