Verner-Morrison Syndrome

At a glance

A very rare syndrome caused by an inappropriate vasoactive intestinal peptide secretion resulting in chronic severe diarrhea leading to severe dehydration and severe hypokalemia resembling cholera. Can be associated with multiple endocrine neoplasias.

Synonyms

WDHA Syndrome; Water Diarrhea, Hypokalemia, Achlorhydria Syndrome; WDHH Syndrome; Water Diarrhea, Hypokalemia, Hypochlorhydria Syndrome; Diarrheagenic Syndrome; Pancreatic Cholera; VIPoma Syndrome.

History

Described by John U. Verner and Ashton B. Morrison, both American physicians, in 1958.

Incidence

3:10,000,000 people in the general population.

Pathophysiology

This disease is caused by inappropriate secretion of vasoactive intestinal peptide (VIP), usually secreted from non-beta islet pancreatic cells in response to food containing fat, proteins, and alcohol. It relaxes smooth muscles, resulting in a decrease of lower esophageal sphincter pressure, relaxation of the gastric antrum and body, and inhibition of gallbladder and intestinal circular muscle contraction. Extra secretion of VIP will provide general manifestations such as vasodilatation, positive inotropic action on the heart, increase in intestinal water and electrolyte secretion, inhibition of gastrin and gastric acid secretion, and stimulation of pancreatic secretion. VIPomas are neuroendocrine tumors.

Diagnosis

Characterized by severe watery diarrhea and dehydration. Diagnosis is confirmed by biochemistry (hypokalemia, hypochloremia, metabolic acidosis, high plasma VIP levels; approximately two-thirds of patients have hypercalcemia and 50% are hyperglycemic), stool analysis (isotonic, alkaline, cultures negative), and ultrasonography and CT imaging (dilated gallbladder, localization of tumors). Prostaglandin E and E₂ hypersecretion can be associated.

Clinical aspects

Hypermotility, watery diarrhea syndromes with hypokalemia and hypochloremia or hyperchloremia, dehydration. Lethargy, muscular weakness, nausea, vomiting, and abdominal pain are frequent. Fluid secretion may exceed 3 to 5 L, with a loss of 200 to 300 mEq of potassium daily. Some cases of VIPoma have included hypercalcemia, flushing, and glucose intolerance. Ectopic primary sites, such as the liver and jejunum, occur in approximately 10% of patients. In children, the VIPoma Syndrome is caused by either a ganglioneuroma or ganglioneuroblastoma. In adults, it is caused by bronchiogenic carcinoma, pheochromocytoma, medullar thyroid carcinoma, and retroperitoneal histiocytoma. Multiple Endocrine Neoplasia Type 1 can be associated (in MEN, hypercalcemia is frequent).

Precautions before anesthesia

Evaluate the extent of the diarrhea (history, clinical repercussion, laboratory investigations including sodium, potassium, calcium urea, creatinine, glucose, arterial blood gas analysis). Also, the tumor repercussion must be assessed because of the risk of obstruction of the duodenum or of the biliary tract and of vascular erosion (radiography, CT, endoscopy). Evaluate existence and repercussion of flushing episodes (history, clinical, heart rate and blood pressure measurement during flush).

Anesthetic considerations

Preoperative hydration and electrolyte correction is necessary based on the laboratory investigations. Elective surgical ...