申覆理由：
Blind loop syndrome, early dumping syndrome及malabsorption皆為Billroth II手術
後之併發症之一, 然而後兩併發症之發生率比blind loop syndrome高出許多, 又同時涵
概原本題目中所提及vitamin B12 deficiency, fat malabsorption, abdominal pain,
distension症狀, 加上blind loop syndrome有其更特異性的診斷法(如下面附件所述),因
此本題應可診斷成兩個常見且合理的術後併發症：1. blind loop syndrome, 2.
malaborption and early dumping syndrome, 治療部份, 若是blind loop syndrome則應
該給予抗生素; 但malaborption add early dumping syndrome則給予營養素補充加上症
狀治療,飲食習慣改變為主,則原本之選項無法符合其治療
申覆資料：
1. Townsend: Sabiston Textbook of Surgery, 18th ed. Chapter 47: Stomach
PEPTIC ULCER DISEASE-- Metabolic Disturbances
The most common metabolic defect appearing after gastrectomy is anemia. Two
types have been identified, and one is related to deficiency in iron and the
other to an impairment in vitamin B12 metabolism. Megaloblastic anemia can
also occur after gastrectomy, especially when more than 50% of the stomach is
removed such as occurs during subtotal gastrectomy. Megaloblastic anemia from
vitamin B12 deficiency only rarely develops after partial gastrectomy.
Vitamin B12 deficiency occurs secondary to poor absorption of the substance
owing to lack of intrinsic factor secretion in the gastric juice. If a
patient develops a macrocytic anemia, serum vitamin B12 levels should be
obtained. If the vitamin B12 level is abnormal, the patient should be treated
with intramuscular injections of cyanocobalamin every 3 to 4 months
indefinitely because its administration orally is not a reliable route.
Another common metabolic disturbance after gastric resections is impaired
absorption of fat. On occasion, steatorrhea may be seen after a Billroth II
gastrectomy and may occur as a result of inadequate mixing of bile salts and
pancreatic lipase with ingested fat because of the duodenal bypass. If this
occurs, a deficiency in uptake of fat-soluble vitamins may also occur. In the
setting of steatorrhea, pancreatic replacement enzymes are often effective in
decreasing fat loss.
Blind Loop Syndrome
Blind loop syndrome is a rare condition manifested by diarrhea, steatorrhea,
megaloblastic anemia, weight loss, abdominal pain, and deficiencies of the
fat-soluble vitamins (A, D, E, and K), as well as neurologic disorders. The
underlying cause of this syndrome is bacterial overgrowth in stagnant areas
of the small bowel produced by stricture, stenosis, fistulas, or diverticula
(e.g., jejunoileal or Meckel's diverticulum). Under normal circumstances, the
upper gastrointestinal tract contains fewer than 105 bacteria/mL, mostly
gram-positive aerobes and facultative anaerobes. The syndrome can be
confirmed by a series of laboratory investigations. Bacterial overgrowth can
be diagnosed with cultures obtained through an intestinal tube or by indirect
tests such as the 14C-xylose or 14C-cholylglycine breath tests. Excessive
bacterial use of 14C substrate leads to an increase in 14CO2. After bacterial
overgrowth and steatorrhea are confirmed, a Schilling test (57Co-labeled
vitamin B12 absorption) may be performed, which should reveal a pattern of
urinary excretion of vitamin B12 resembling that of pernicious anemia (a
urinary loss of 0%-6% of vitamin B12 compared with the normal of 7%-25%). In
patients with blind loop syndrome, vitamin B12 excretion is not altered by
the addition of intrinsic factor, but a course of a broad-spectrum antibiotic
(e.g., tetracycline) should return vitamin B12 absorption to normal.
2.
Harrison’s pronciples for internal medicine, 17th edition
Part 13: disorders of gastrointestinal system, section 1:
Dumping Syndrome
Dumping syndrome consists of a series of vasomotor and gastrointestinal signs
and symptoms and occurs in patients who have undergone vagotomy and drainage
(especially Billroth procedures). Two phases of dumping, early and late, can
occur. Early dumping takes place 15–30 min after meals and consists of
crampy abdominal discomfort, nausea, diarrhea, belching, tachycardia,
palpitations, diaphoresis, light-headedness, and, rarely, syncope. These
signs and symptoms arise from the rapid emptying of hyperosmolar gastric
contents into the small intestine, resulting in a fluid shift into the gut
lumen with plasma volume contraction and acute intestinal distention. Release
of vasoactive gastrointestinal hormones (vasoactive intestinal polypeptide,
neurotensin, motilin) is also theorized to play a role in early dumping.
Dietary modification is the cornerstone of therapy for patients with dumping
syndrome. Small, multiple (six) meals devoid of simple carbohydrates coupled
with elimination of liquids during meals is important. Antidiarrheals and
anticholinergic agents are complementary to diet.
Maldigestion and Malabsorption
Weight loss can be observed in up to 60% of patients after partial gastric
resection. A significant component of this weight reduction is due to
decreased oral intake. However, mild steatorrhea can also develop. Reasons
for maldigestion/malabsorption include decreased gastric acid production,
rapid gastric emptying, decreased food dispersion in the stomach, reduced
luminal bile concentration, reduced pancreatic secretory response to feeding,
and rapid intestinal transit.
Decreased serum vitamin B12 levels can be observed after partial gastrectomy.
This is usually not due to deficiency of IF, since a minimal amount of
parietal cells (source of IF) are removed during antrectomy. Reduced vitamin
B12 may be due to competition for the vitamin by bacterial overgrowth or
inability to split the vitamin from its protein-bound source due to
hypochlorhydria.
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