Kamran Idrees, M.D., John D. Christein, M.D.
1 Which of the following statements is true with regard to the arterial blood supply of the stomach?
A The left gastroepiploic artery commonly arises from the left gastric artery.
B Ligation of the left gastric artery can result in acute left-sided hepatic ischemia.
C The stomach is extremely susceptible to ischemia because of poor collateral circulation.
D The inferior phrenic and short gastric arteries provide significant blood supply to the body of the stomach.
E A replaced right hepatic artery may originate from the left gastric artery.
Ref.: 1, 2
Comments
The arterial blood supply of the stomach is derived primarily from the celiac artery. The left gastric artery comes off of the celiac artery and supplies the stomach along the lesser curvature. An aberrant/replaced left hepatic arteryoriginates from the left gastric artery (15% to 24%) and can represent the only arterial blood supply to the left hepatic lobe. This aberrant/replaced left hepatic artery runs in the gastrohepatic ligament. The right gastric arterytypically arises from the common hepatic artery distal to the gastroduodenal artery. The right and left gastroepiploic arteries usually originate from the gastroduodenal artery and splenic artery, respectively. The short gastric arteries arising from the splenic artery and inferior phrenic arteries also contribute significant blood volume to the proximal part of the stomach. The stomach is well protected from ischemia and can easily survive with ligation of three of four arteries because of its rich collateral circulation.
Answer
B
2 After esophagectomy, the arterial blood supply of a gastric conduit is primarily based on which of the following vessels?
A Left gastroepiploic artery
B Left gastric artery
C Right gastroepiploic artery
D Right gastric artery
E Inferior phrenic arteries
Ref.: 1, 2
Comments
During gastric mobilization for esophageal replacement after esophagectomy, the left gastric artery and short gastric (vasa brevia) arteries are routinely divided. The major arterial source for the neoesophagus (gastric conduit) is derived from the right gastroepiploic artery.
Answer
C
3 Choose the correct type of vagotomy with the appropriate level of vagal transection from the pairs listed below:
A Truncal vagotomy/criminal nerve of Grassi
B Highly selective vagotomy/anterior and posterior vagal trunks below the celiac and hepatic branches
C Selective vagotomy/anterior and posterior vagal trunks above the celiac and hepatic branches
D Parietal cell vagotomy/terminal branches of the nerve of Latarjet
E Highly selective vagotomy/hepatic branches
Ref.: 1, 2
Comments
In the chest, the vagal trunks are situated to the right and left of the esophagus. At the level of the cardia, the left vagal trunk is found anterior and the right vagal trunk is found posterior secondary to embryonic gastric rotation. The anterior vagal trunk divides into hepatic and anterior gastric (anterior nerve of Latarjet) branches. The posterior vagus divides into the posterior nerve of Latarjet and celiac branches. One of the proximal posterior branches of the posterior vagal trunk is known as the criminal nerve of Grassi and is identified as a possible cause of recurrent ulcers if left undivided during selective vagotomy. Truncal vagotomy is conventionally performed at or just above or below the diaphragmatic esophageal hiatus before it gives off celiac and hepatic branches. In contrast, selective vagotomy is performed distal to this location and spares the celiac and hepatic branches. Highly selective vagotomy(also known as proximal gastric or parietal cell vagotomy) divides individual terminal branches of the nerve of Latarjet in the fundus and corpus of the stomach but spares the vagal branches to the antrum and pylorus, which control gastric motility and emptying—thus obviating the need for a drainage procedure.
Answer
D
4 Which cell type is matched with the appropriate secretory product?
A Parietal cell/ghrelin
B Chief cell/pepsinogen
C G cell/intrinsic factor
D Delta cell/gastrin
E Endocrine cell/somatostatin
Ref.: 1, 2
Comments
See Question 5.
Answer
B
5 Which cell type is matched with the correct primary anatomic location?
A Parietal cell/gastric cardia
B Chief cell/gastric cardia
C G cell/gastric antrum
D Delta cell/duodenum
E Endocrine cell/gastric corpus and fundus
Ref.: 1, 2
Comments
The gastric mucosa consists of surface columnar epithelial cells and glands containing various cell types. The mucosal cells vary in their anatomic location and secretory function. Parietal and chief cells are located predominantly in the gastric fundus and corpus. Parietal cells produce hydrochloric acid and intrinsic factors, whereas chief cells secrete pepsinogen. The G cells of the antrum are the primary source of gastrin. Somatostatin is synthesized and stored in delta cells located in the gastric corpus and antrum. Mucus is secreted by gastric surface epithelial cells, neck cells, and the Brunner gland. Ghrelin, produced by endocrine cells of the gastric body, probably plays a role in the neuroendocrine response to changes in nutritional status and may be used to help in the treatment or prevention of obesity, or both, in the future.
Answer
C
6 Acid secretion is stimulated by the following parietal cell receptors except:
A Acetylcholine
B Secretin
C Histamine
D Gastrin
E All of the above
Ref.: 1, 2
Comments
See Question 7.
Answer
B
7 The final common pathway of acid secretion by parietal cells involves which of the following?
A Protein kinase
B Increased intracellular Ca2+
C Hydrogen-potassium adenosine triphosphatase (H+,K+-ATPase)
D Phosphorylase kinase
E Adenylate cyclase
Ref.: 1, 2
Comments
It is important to have knowledge of the cellular basis for parietal cell acid secretion to understand the pharmacologic control of acid. The parietal cell has three specific plasma membrane receptors that stimulate acid secretion: acetylcholine, histamine, and gastrin receptors. All three receptors activate the H+,K+-ATPase pump, which results in secretion of hydrogen ion for potassium. Acetylcholine- and gastrin-stimulated secretion depends on specific membrane phospholipases and increases intracellular calcium levels, with subsequent phosphorylase kinase–induced phosphorylation and H+,K+-ATPase activity. Histamine activates adenylate cyclase, which in turn leads to protein phosphorylation via protein kinase and H+,K+-ATPase activation. Somatostatin, cholecystokinin, and secretin inhibit acid secretion.
Answer
C
8 All of the following stimulate gastric acid secretion except:
A Gastric distention
B Duodenal gastrin
C Acetylcholine
D Intraluminal protein
E Somatostatin
Ref.: 1, 2
Comments
Gastric acid secretion is regulated in three phases: cephalic, gastric, and intestinal. The cephalic phase is primarily mediated by the vagus nerve. Vagal stimulation (acetylcholine) directly releases acid from the parietal cells, in addition to releasing gastrin from the antrum. The gastric phase is initiated by gastric distention, intraluminal peptides, and amino acids and results in the release of gastrin. The majority of gastrin is released in the antrum with a small amount being secreted from the duodenal mucosa. The intestinal phase of gastric secretion accounts for only 10% of the total acid volume. Duodenal gastrin and the hypothetical peptide hormone enterooxyntin have been postulated to mediate the intestinal phase of acid secretion. Luminal acidity releases secretin and somatostatin, which inhibit acid secretion.
Answer
E
9 Which intestinal hormone is matched with the correct function?
A Secretin/acts as a universal “on” switch
B Gastrin-releasing peptide/acts as a universal “off” switch
C Somatostatin/stimulates intestinal secretion and motility
D Motilin/acts as a universal “on” switch
E Vasoactive intestinal peptide (VIP)/stimulates intestinal secretion and motility
Ref.: 1, 2
Comments
Gastrointestinal (GI) hormones are secreted by endocrine cells that are widely distributed and localized to specific GI mucosa. These hormones regulate GI secretion, motility, and absorption in a complex fashion. Secretin is released by S cells located in the duodenum and jejunum. The primary function of secretin is to induce the release of water and bicarbonate from pancreatic ductal cells. Secretin also inhibits the release of gastrin, gastric acid secretion, and gastric motility. Gastrin-releasing peptide (also known as bombesin) is found throughout the GI tract. It acts as the universal “on” switch by stimulating all GI hormones (except secretin), as well as GI secretions and motility. Somatostatin is produced by delta cells located primarily in the pancreas and gastric antrum. Because of its wide inhibitory action, somatostatin is known as the universal “off” switch of the intestinal tract. It inhibits the release of all GI hormones along with the inhibition of enteric water, electrolyte secretion, and motility. Motilin, secreted by M cells in the duodenum and jejunum, stimulates upper GI motility. Erythromycin is thought to increase GI motility through the activation of motilin receptors. Vasoactive intestinal peptide is present throughout the length of the intestinal tract and the central nervous system. It is a potent stimulator of intestinal secretion. VIP is the chief culprit in the watery diarrhea, hypokalemia, and achlorhydria syndrome (WDHA) associated with pancreatic endocrine tumors (also known as Verner-Morrison syndrome or VIPoma).
Answer
E
10 Which hormone is matched with the correct diagnostic/therapeutic function?
A Cholecystokinin/treatment of esophageal variceal bleeding
B Somatostatin/relief of spasm of the sphincter of Oddi
C Gastrin/measurement of maximal gastric acid secretion
D Glucagon/provocative test for gastrinoma
E Secretin/stimulation of gallbladder contraction
Ref.: 1, 2
Comments
GI hormones or their analogues have been used clinically as diagnostic or therapeutic agents. Cholecystokinin (CCK) is used to stimulate gallbladder contraction. This is useful in identifying patients with biliary dyskinesia or acalculous cholecystitis with the help of CCK cholescintigraphy. Pentagastrin, a gastrin analogue, is used to measure gastric acid secretion. Somatostatin or its analogues are used in various conditions as a result of their universal inhibitory function. Because they inhibit the release of GI hormones, somatostatin analogues are used for various endocrine neoplasms such as Zollinger-Ellison syndrome, VIPoma, insulinoma, and carcinoid tumors. They are also useful in patients with pancreatic fistulas, pancreatic ascites, and enterocutaneous fistulas by decreasing GI secretions. Additionally, they have been used as a treatment to decrease bleeding from the GI tract. Glucagon is used by endoscopists to relax the Sphincter of Oddi to facilitate endoscopic retrograde cholangiopancreatography (ERCP). Secretin, which inhibits acid secretion, causes a paradoxical increase in serum gastrin levels in patients with gastrinoma. Pancreatic polypeptide (PP) is predominantly secreted in the pancreatic head. PP serum levels drop following the Whipple procedure and may be related to the delayed gastric emptying observed after pyloric-preserving pancreatoduodenectomy. In addition, PP secretion necessitates intact vagal nerve function; thus, a blunt response to stimulation by sham feedings has been used to evaluate intact vagal nerve function, particularly in patients suspected of having iatrogenic vagus nerve injury.
Answer
C
11 With regard to regulation of gastric emptying, which of the following statements is true?
A The greater the volume present in the stomach, the slower the gastric emptying.
B Higher intake of lipids slows gastric emptying.
C Emptying of solids is dependent on fundal tone.
D Emptying of liquids is dependent on antral propulsion.
E The lower esophageal sphincter regulates gastric volume.
Ref.: 1, 2
Comments
Gastric emptying is regulated largely by neural and hormonal factors triggered by gastric volume and composition. Generally, the greater the volume, the faster the contents empty. Liquids empty faster than solids. The pattern of liquid emptying is exponential and is largely determined by fundal tone. Solids are reduced in size to particles 1 to 2 mm in diameter by propulsive and retropulsive activity. Gastric emptying is linear after an initial lag and depends on mechanical action of the pyloroantral region. Higher caloric intake, in the form of lipids, slows gastric emptying. The lower esophageal sphincter does not control gastric volume.
Answer
B
12 Which of the following clinical conditions is not associated with delayed gastric emptying?
A Hypocalcaemia
B Scleroderma
C Hyperglycemia
D Myxedema
E Zollinger-Ellison syndrome
Ref.: 1-3
Comments
Disorders of gastric emptying can be divided into rapid or delayed emptying, both of which can be significantly disabling conditions. Delayed gastric emptying is the more frequently encountered problem of gastric motility. Excluding mechanical obstruction, important causes of delayed gastric emptying include metabolic derangements (e.g., myxedema and hyperglycemia), electrolyte abnormalities (e.g., hypokalemia and hypocalcaemia), drugs(e.g., narcotics and anticholinergics), and systemic diseases (e.g., diabetes mellitus and scleroderma). Up to 40% of postvagotomy patients experience delayed gastric emptying. Rapid gastric emptying is less commonly observed. Causes of rapid gastric emptying include previous gastric resection, conditions with impaired fat absorption resulting in loss of the inhibition of gastric emptying (e.g., pancreatic insufficiency and short bowel syndrome), and conditions with hypergastrinemia such as Zollinger-Ellison syndrome.
Answer
E
13 Infection with Helicobacter pylori has been associated with all but which of the following conditions?
A Duodenal ulcer
B Gastric cancer
C Mucosa-associated lymphoid tissue (MALT) lymphoma
D Gastroesophageal reflux disease (GERD)
E Chronic gastritis
Ref.: 1, 2, 4
Comments
H. pylori is a curved or S-shaped, gram-negative microaerophilic motile bacterium whose natural habitat is the human stomach. H. pylori infection has been demonstrated to be associated with 90% of duodenal ulcers and 75% of gastric ulcers. After eradication of the organism as part of ulcer treatment, recurrence of ulcer is extremely rare. In addition, H. pylori has been associated with chronic atrophic gastritis, which in turn leads to gastric atrophy and intestinal metaplasia, a suspected precursor of gastric cancer. H. pylori infection also increases the risk for low-grade mucosa-associated lymphoid tissue lymphoma; eradication of H. pylori results in resolution of MALT lymphomas in most cases. There appears to be a negative association between H. pylori infection and gastrointestinal reflux disease.
Answer
D
14 Which of the following tests is not appropriate for the initial detection of H. pylori infection in patients with peptic ulcer disease?
A Urea breath test
B Histologic examination of mucosa
C Rapid urease test
D Culture and sensitivity testing
E H. pylori serology
Ref.: 1, 5, 6
Comments
See Question 15.
Answer
D
15 Which of the following tests is best to document eradication of H. pylori infection in patients with peptic ulcer disease?
A Urea breath test
B Histologic examination of mucosa
C Rapid urease test
D Culture and sensitivity testing
E H. pylori serology
Ref.: 1, 5, 6
Comments
It is important to document the presence or absence of Helicobacter pylori to adequately treat patients with peptic ulcer disease. Both invasive and noninvasive tests are available for the diagnosis of H. pyloriinfection. Invasive testsrequire endoscopic mucosal biopsy and include histologic examination, the rapid urease test, and culture. Noninvasive tests include the urea breath test and serology. Histologic examination can accurately diagnose H. pyloriwith two biopsy specimens with high sensitivity and specificity (90%). The rapid urease test on a mucosal biopsy specimen uses a change in pH resulting from the breakdown of urea by a urease enzyme produced by H. pylori. This test is considered the initial test of choice because of its simplicity, accuracy, and rapid results. Culture of H. pylori has the most specificity (100%) but is difficult to perform and is currently not widely available. Cultures should usually be reserved for research purposes or patients with suspected antibiotic resistance. The urea breath test is a noninvasive test that analyzes breath for labeled carbon dioxide produced by bacterial urease from the conversion of ingested labeled urea. Because of its noninvasiveness plus high sensitivity and specificity (95%), the urea breath test is considered the test of choice for documentation of H. pylori eradication. Serologic tests are quick and inexpensive but cannot differentiate between active infection and previous exposure. Serology is useful for the initial diagnosis of H. pylori infection in patients in whom endoscopy is not indicated.
Answer
A
16 Which condition corresponds to the appropriate basal and pentagastrin-stimulated acid output?
A Duodenal ulcer/basal and pentagastrin-stimulated acid output is decreased
B Pernicious anemia/basal and pentagastrin-stimulated acid output is decreased
C Gastric cancer/basal and pentagastrin-stimulated acid output is decreased
D Zollinger-Ellison syndrome/basal and pentagastrin-stimulated acid output is increased
E Gastric atrophy/basal and pentagastrin-stimulated acid output is decreased
Ref.: 1, 2
Comments
The normal mean basal acid output is in the range of 1 to 8 mmol/h, and the response to pentagastrin-stimulated output ranges from 6 to 40 mmol/h. In patients with duodenal ulcer and Zollinger-Ellison syndrome, both basal acid output and pentagastrin-stimulated acid output are decreased. In contrast, adults with pernicious anemia, gastric atrophy, and gastric cancer are achlorhydric or have subnormal acid output. In these patients, maximal acid output remains decreased despite pentagastrin evaluation.
Answer
A
17 Elevated serum gastrin levels during fasting are typical in all but which of the following conditions?
A Short bowel syndrome
B Pernicious anemia
C Chronic gastritis
D Duodenal ulcer
E Gastric outlet obstruction
Ref.: 1, 2, 6
Comments
Conditions associated with hypergastrinemia and increased acid secretion include Zollinger-Ellison syndrome, antral G-cell hyperplasia, retained antrum, renal failure, gastric outlet obstruction, and short bowel syndrome. In contradistinction, an elevated serum gastrin level with normal or diminished acid output is seen in patients with pernicious anemia, postvagotomy states, chronic gastritis, and gastric cancer and in patients with pharmacologic acid suppression. Serum gastrin levels during fasting are normal in patients with duodenal ulcer but may be excessively elevated postprandially. The absolute level of an abnormally elevated serum gastrin level is not necessarily indicative of the cause. However, marked elevations (>1000 pg/mL) are often associated with Zollinger-Ellison syndrome. Ulcerogenic causes of hypergastrinemia resulting from elevated gastric acid secretion include Zollinger-Ellison syndrome, antral G-cell hyperplasia, retained antrum, short bowel syndrome, and gastric outlet obstruction. Zollinger-Ellison syndrome and antral G-cell hyperplasia are uncommon, but they must be differentiated to determine proper therapy. Both are associated with elevated gastrin and gastric acid levels. They can be differentiated on the basis of the serum gastrin response to several provocative tests. A pronounced increase in serum gastrin levels after the intravenous infusion of secretin is typically seen with Zollinger-Ellison syndrome. Elevations can occur with other conditions, but they are not as dramatic. In contradistinction, more marked increases in gastrin levels occur after stimulation by a protein in Zollinger-Ellison syndrome.
Answer
D
18 With regard to H. pylori–negative duodenal ulcer disease, all of the following statements are correct except:
A Nonsteroidal anti-inflammatory drugs (NSAIDs) are a major cause of duodenal ulcers in patients who are H. pylori negative.
B Because of the high prevalence of H. pylori–positive duodenal ulcers, patients should be treated for H. pylori without confirmatory testing.
C In contrast to H. pylori–positive duodenal ulcers, NSAID-induced ulcers are not frequently associated with chronic active gastritis.
D H. pylori–negative duodenal ulcers are usually large ulcers and multiple and are often associated with bleeding.
E Older age, multiple comorbid conditions, and sepsis are independently associated with H. pylori–negative duodenal ulcers.
Ref.: 1, 6
Comments
Initial studies have demonstrated that Helicobacter pylori infection is present in more than 90% of patients with duodenal ulcers. However, more recently it has been shown that the prevalence of H. pylori–associated duodenal ulcers is only 75% and is found to be decreasing. Thus, it is important to first make the diagnosis of an active H. pylori infection rather than initiating empirical therapy. Helicobacter pylori–negative duodenal ulcers are independently associated with nonsteroidal anti-inflammatory drug use, older age, multiple medical problems, and sepsis. Use of NSAIDs is the major cause of duodenal ulcers in patients who are H. pylori–negative. Bleeding is the initial manifestation in these patients and they have large and multiple ulcers.
Answer
B
19 A 45-year old man requires surgery for an intractable duodenal ulcer. Which operation best prevents ulcer recurrence?
A Subtotal gastrectomy
B Truncal vagotomy and pyloroplasty
C Truncal vagotomy and antrectomy
D Selective vagotomy
E Highly selective vagotomy
Ref.: 1, 2, 6
Comments
See Question 20.
Answer
C
20 Which operation for duodenal ulcer is least likely to produce undesirable postoperative symptoms?
A Subtotal gastrectomy
B Truncal vagotomy and pyloroplasty
C Truncal vagotomy and antrectomy
D Selective vagotomy
E Highly selective vagotomy
Ref.: 1, 2, 6
Comments
The goal of surgical therapy for duodenal ulcers is to reduce acid production in a manner that is safe and has the fewest possible side effects. Acid can be reduced by eliminating vagal stimulation, removing the antral source of gastrin, and removing the parietal cell mass. Traditionally, subtotal two-thirds gastrectomy has carried the highest mortality rate. Truncal vagotomy with antrectomy has the lowest recurrence rate. Procedures involving antrectomy, pyloroplasty, or truncal vagotomy may be complicated by diarrhea, postprandial dumping, or bile reflux. Selective vagotomy, which preserves the hepatic and celiac vagal branches, has been associated with a lower rate of diarrhea than truncal vagotomy has. Highly selective vagotomy, also known as parietal cell vagotomy, aims to denervate the parietal cell–bearing portion of the stomach but preserve innervations to the pyloroantral region and thus maintain more normal gastric emptying. This operation carries the lowest mortality rate, the lowest incidence of side effects, but the highest recurrence rate, which ranges from 5% to 15%.
Answer
E
21 A 75-year-old man taking NSAIDs for arthritis has an acute abdomen and pneumoperitoneum. His symptoms are 6 hours old and his vital signs are stable after the infusion of 1 L of normal saline solution. What should be the next step in the management of this patient?
A Computed tomography of the abdomen
B Esophagogastroduodenoscopy (EGD)
C Antisecretory drugs, broad-spectrum antibiotics, and surgery if he fails to improve in 6 hours
D Antisecretory drugs, antibiotics for H. pylori, and surgery if he fails to improve in 6 hours
E Surgery
Ref.: 1, 2, 6
Comments
See Question 23.
Answer
E
22 The patient in Question 21 is found to have a perforated duodenal ulcer. Which of the following best describes the required operation?
A Suture closure of the perforation
B Omental patch of the perforation
C Repair of the perforation and highly selective vagotomy
D Repair of the perforation and truncal vagotomy
E Repair of the perforation and gastric resection
Ref.: 1, 2, 6
Comments
See Question 23.
Answer
B
23 If the patient in Question 21 were found to have a perforated gastric ulcer instead of a duodenal ulcer, what additional steps, if any, need to be performed at the time of operative intervention beside closure of the perforation?
A Feeding jejunostomy
B Gastrojejunostomy
C Gastrostomy tube placement
D Excision or biopsy of the ulcer
E Pyloroplasty
Ref.: 1, 6
Comments
The preferred treatment of a perforated duodenal ulcer is resuscitation and prompt surgery. Nonoperative management is reserved for old contained perforations or for terminally ill patients who otherwise cannot undergo surgery. The diagnosis is a presumptive one based on clinical grounds and should not be excluded if pneumoperitoneum cannot be demonstrated, because about 20% of patients with perforations do not have this typical radiographic feature. Operative management requires closure of the perforation, which is generally best accomplished with an omental (Graham) patch. Closure of the perforation is usually sufficient in patients with duodenal ulcers; however, excision of the ulcer is necessary to rule out malignancy in patients with gastric ulcers before closure. Following simple repair alone, the traditional natural history has been that about one third of patients have no further ulcer problems, one third have ulcer recurrence amenable to medical management, and one third require a subsequent operation for ulcer disease. It is not clear how precisely this applies to patients with H. pylori infection or those with NSAID-induced ulcers. Definitive operations should be performed only in stable patients and those with documented failure after appropriate H. pylori eradication. Truncal vagotomy can be performed expeditiously but has a greater incidence of side effects. Highly selective vagotomy is an excellent choice but is time-consuming and requires a surgeon with the expertise to perform it. Resective procedures are generally avoided in the setting of perforation because of higher morbidity. Following surgery, ulcerogenic drugs should be withheld, and any concomitant H. pylori infection should be treated.
Answer
D
24 The most common cause of gastric outlet obstruction in adults is:
A Peptic ulcer disease
B Extrinsic neoplastic compression
C Cancer
D Primary lymphoma of the stomach
E Duodenal Crohn’s disease
Ref.: 1, 5, 6
Comments
With increased use of histamine receptor blockers and proton pump inhibitors in the medical management of peptic ulcer disease and effective treatment of H. pylori infection, malignancy is the most common cause of gastric outlet obstruction instead of peptic ulcer disease. Among malignancies, primary adenocarcinomas of the pancreas, stomach, and duodenum (in decreasing order of frequency) are the leading cause of gastric outlet obstruction. Gastrointestinal stromal tumors (GISTs) of the stomach and duodenum and primary lymphomas of the stomach, duodenum, and pancreas are other causes of gastric outlet obstruction. Extrinsic compression from metastatic disease to the porta hepatis can also lead to obstruction. It is therefore important to have a high index of suspicion for a malignancy when a patient has gastric outlet obstruction rather than mistaking it for a benign obstruction from peptic ulcer disease.
Answer
C
25 A patient with gastric outlet obstruction and prolonged vomiting has which of the following metabolic abnormalities?
A Hypochloremic, hyperkalemic metabolic alkalosis
B Hyperchloremic, hypokalemic metabolic acidosis
C Hyponatremic, hypokalemic metabolic acidosis
D Hypochloremic, hypokalemic metabolic alkalosis
E Hyperchloremic, hyperkalemic metabolic acidosis
Ref.: 1, 2
Comments
The classic metabolic abnormality resulting from gastric outlet obstruction and prolonged vomiting is hypochloremic, hypokalemic metabolic alkalosis. Initial loss of hydrochloric acid causes hypochloremia and mild alkalosis compensated for by renal excretion of bicarbonate. Therefore, in the early stages the urine is alkaline. Continued vomiting produces a severe extracellular fluid deficit and sodium deficit from both renal and gastric losses. The kidneys begin to conserve sodium and, in exchange, excrete hydrogen and potassium cations to accompany bicarbonate. The kidneys are the predominant site of potassium loss, and the urine is paradoxically acidic. Urine chloride content is reduced throughout and eventually absent. Serum ionized calcium levels are decreased because calcium is mildly alkaline and shifts to its nonionized form to reduce alkalosis. Treatment of this metabolic situation is accomplished primarily by the administration of isotonic saline solution, which replenishes the deficits in volume, sodium, and chloride. Potassium is replaced once renal function is optimized.
Answer
D
26 Which of the following endoscopic ulcer characteristics has the highest risk for recurrent bleeding?
A Oozing ulcer
B Clean based ulcer
C Nonbleeding “visible vessel”
D Nonbleeding ulcer with an overlying clot
E Dieulafoy ulcer
Ref.: 6
Comments
Esophagogastroduodenoscopy is not only the diagnostic test of choice but can also be therapeutic in patients with upper gastrointestinal bleeding. EGD can localize the bleeding site and determine the risk for rebleeding based on the appearance of the ulcer bed. The endoscopic features of ulcers with a risk for rebleeding in decreasing order of frequency are active arterial bleeding (approaches 100%), nonbleeding “visible vessel” (≈50%), nonbleeding ulcer with an overlying clot (≈30% to 35%), oozing ulcer (≈10% to 27%), and a clean based ulcer (<3%). Dieulafoy ulcers are vascular malformations that bleed when superficial erosion into the vessel occurs. Unless actively bleeding, they are difficult to diagnose endoscopically.
Answer
C
27 During an operation for a bleeding duodenal ulcer, three-point “U” stitches are placed to ligate which of the following arteries after longitudinal pyloroduodenotomy?
A Common hepatic, right gastric, and gastroduodenal arteries
B Proximal and distal gastroduodenal and transverse pancreatic arteries
C Right gastric, gastroduodenal, and right gastroepiploic arteries
D Right gastric and anterior and posterior inferior pancreaticoduodenal arteries
E Common hepatic, gastroduodenal, and superior mesenteric arteries
Ref.: 1, 2, 4, 6
Comments
Massive bleeding is usually the result of posterior erosion of a duodenal ulcer into the gastroduodenal artery. Emergency surgical intervention is indicated when bleeding is refractory to endoscopic therapy or in the presence of hemorrhagic shock. After expeditious preoperative resuscitation, the abdomen is entered and a longitudinal pyloroduodenotomy is performed. Digital pressure is applied over the ulcer base to temporize the bleeding and allow resuscitation before suture control is obtained. Proper control of bleeding requires three-point suture ligation of the duodenal ulcer. These “U” stitches are placed superior and inferior to the site of penetration to ligate the proximal and distal gastroduodenal artery. A third suture is placed on medial aspect of the ulcer to control the transverse pancreatic branch coming off the gastroduodenal artery. After the bleeding is controlled, biopsy of gastric mucosa should be performed for histologic analysis for H. pylori. The longitudinal pyloroduodenotomy is then closed transversely (Heineke-Mikulicz or Weinberg pyloroplasty).
Answer
B
28 Which type of gastric ulcer corresponds with the correct anatomic location?
A Type I/prepyloric region
B Type II/lesser curvature of the stomach near the GE junction
C Type III/body of the stomach along the lesser curvature
D Type IV/lesser curvature of the stomach near the GE junction
E Type IV/prepyloric region
Ref.: 1, 4, 6
Comments
See Question 30.
Answer
D
29 Which type of gastric ulcer corresponds with the associated acid secretion?
A Type I/high acid secretion
B Type II/high acid secretion
C Type III/normal or low acid secretion
D Type IV/high acid secretion
E All of the above
Ref.: 1, 4, 6
Comments
See Question 30.
Answer
B
30 Which gastric ulcer corresponds with the correct recommended surgical management?
A Type I/Billroth I or II reconstruction
B Type II/truncal vagotomy and pyloroplasty
C Type III/Csendes gastrectomy with Roux-en-Y gastrojejunostomy or Pauchet gastrectomy and Billroth I reconstruction
D Type IV/Billroth I or II reconstruction with truncal vagotomy
E Type IV/total gastrectomy
Ref.: 1, 4, 6
Comments
Benign gastric ulcers have been classified in terms of their anatomic location. Type I ulcers are the most common (50%) and occur in the body of the stomach along the lesser curvature. These ulcers are associated with low to normal acid secretion. Type II gastric ulcers (25%) also occur in the body of the stomach but have associated duodenal ulcers. Type III gastric ulcers (20%) are located in the prepyloric region. Both type II and type III ulcers are associated with excessive acid secretion. Type IV ulcers are the least common (<10%) and occur near the GE junction along the lesser curve. Like type I ulcers, they are associated with low or normal acid secretion. Surgical intervention is indicated for patients who have failed maximal medical therapy (12 weeks), for those in whom complications develop, or for those in whom malignancy cannot be ruled out. Surgical therapy for benign gastric ulcers depends on the type of ulcer and its associated acid secretion. Type I ulcers are usually well treated with antrectomy or hemigastrectomy (including removal of the ulcer) without vagotomy. Type IV ulcers do not require vagotomy either. Type IV ulcers near the GE junction can be treated by modifications of distal gastrectomy that include ulcer excision. Distal gastrectomy with extension along the lesser curvature to include the ulcer (Pauchet procedure) and Billroth I reconstruction can be performed for ulcers that are 2 to 5 cm from the GE junction. For type IV ulcers at the GE junction, subtotal gastrectomy with Roux-en-Y jejunal reconstruction (Csendes procedure), a rotational Tanner gastrectomy, or a Kahler-Muhlenbergprocedure should be performed. Because type II and type III ulcers are associated with acid hypersecretion, they are treated as duodenal ulcers. Truncal vagotomy with Billroth I or II reconstruction is the preferred surgical therapy because it accomplishes both goals of a decrease in acid secretion and excision of the ulcer.
Answer
A
31 Concerning the treatment of patients with Zollinger-Ellison syndrome, which of the following statements is true?
A Operative treatment of associated hyperparathyroidism takes precedence over abdominal surgery.
B Pancreatic tumors should not be removed by enucleation.
C Duodenal tumors usually require pancreaticoduodenectomy.
D Total gastrectomy is indicated if the tumor cannot be localized.
E Resection of liver metastases is not indicated.
Ref.: 1-3
Comments
Treatment of Zollinger-Ellison syndrome is two pronged and aimed at both resecting the tumor when possible and protecting the gastric end-organ. Therapy must be individualized. Patients with known endocrine tumors should undergo careful evaluation for other potential endocrine tumors. In patients with gastrinoma and hyperparathyroidism, parathyroidectomy should be performed first to eliminate hypercalcemia. Abdominal surgery is not urgent with the current antisecretory medications. Although gastrinomas are often multiple and are usually metastatic, long-term survival is possible. Aggressive attempts to localize and resect tumors can provide cure in 5% to 20% of patients and can diminish gastrin secretion in others. Most gastrinomas can be found in the triangle of Passaro. Digital palpation through a duodenotomy and intraoperative ultrasound are useful operative adjuncts. Both pancreatic and duodenal gastrinomas can be resected by enucleation when appropriately located. Blind pancreatic resections are not generally indicated. When complete tumor removal is not possible, a gastric operation may be appropriate. Proximal gastric vagotomy may be useful, but total gastrectomy still provides the best long-term quality of life for some patients. Life-long pharmacologic treatment with antisecretory agents may control the ulcer diathesis in some patients, but problems with high doses, compliance, and side effects may occur. Resection or ablation of metastatic disease, although not curative, can provide important palliation and decrease the need for drug therapy.
Answer
A
32 With regard to the epidemiologic characteristics of gastric cancer, which of the following statements is false?
A The highest incidence is found in Japan.
B Gastric cancer is twice as common in males as in females.
C The incidence of gastric adenocarcinoma of the distal portion of the stomach has increased in the past several decades.
D There is a higher incidence in patients with blood group A.
E There is a higher incidence in patients who have undergone gastric resection for duodenal ulcer.
Ref.: 1, 6, 7
Comments
The significant geographic variations in the incidence of gastric cancer are probably related to environmental and dietary differences that result in exposure to N-nitroso compounds, polycyclic hydrocarbons, and other potential carcinogens. The highest incidence is found in Japan, with lower rates in the United States and Western Europe. Gastric cancer occurs more frequently in males all over the world, and the incidence is higher in African-American men than in white men in the United States. The incidence of adenocarcinoma of the gastric cardia and GE junction has gradually increased, whereas that of the distal part of the stomach has decreased over the past few decades. Although most risk factors for gastric cancer are probably exogenous, genetic factors may also be involved, as exemplified by patients with pernicious anemia and by slightly increased risk in patients with blood group A. There is also an increased risk 10 to 15 years after gastric resection for benign disease, perhaps indicative of the role of bile reflux.
Answer
C
33 All of the following conditions are associated with gastric cancer except:
A Chronic atrophic gastritis
B H. pylori infection
C Hereditary nonpolyposis colorectal cancer
D Adenomatous gastric polyps
E Fundic gland polyps
Ref.: 1, 6, 7
Comments
Certain gastric lesions have a significant association with gastric adenocarcinoma and can be considered precursors to malignancy. Chronic atrophic gastritis, of which several forms are recognized, underlies most gastric cancers. The epithelial changes of intestinal metaplasia and dysplasia are premalignant. Autoimmune chronic gastritis involves the body and fundus of the stomach. It is associated with pernicious anemia, achlorhydria, very high gastrin levels, and a high risk for cancer. Hypersecretory chronic gastritis involves the gastric antrum and is associated with peptic ulcer disease but not malignancy. Helicobacter pylori infection may be the most important risk factor for gastric adenocarcinoma worldwide. The IgG antibody positivity in various populations correlates with the local incidence of gastric cancer. Hereditary nonpolyposis colorectal cancer is an inheritable risk factor for gastric cancer. Adenomatous gastric polyps have malignant potential similar to colonic adenomatous polyps. The risk increases with increasing size of the polyp. Fundic gland polyps are benign and have no malignant potential.
Answer
E
34 With regard to the surgical treatment of gastric adenocarcinoma, which of the following statements is true?
A Total gastrectomy for antral lesions results in longer survival than does partial gastrectomy.
B Routine splenectomy does not improve survival rates.
C Extended lymph node dissection improves survival rates in patients with stages I and II lesions.
D Total gastrectomy for palliation is contraindicated.
E Linitis plastica should be resected to histologically negative margins.
Ref.: 1, 6, 7
Comments
Gastric adenocarcinoma is preferably treated by resection, although resection usually proves to be palliative. The general strategy for curative resection is to remove as much of the stomach as necessary to obtain free margins and to perform limited node dissection. Although data from Japan support the benefit of extended nodal dissection (celiac, mesenteric, hepatic, and paraaortic), studies in the United States have not generally confirmed this benefit. Furthermore, these extended dissections can be associated with substantial morbidity. Most resections entail distal subtotal gastrectomy. Total gastrectomy is appropriate for locally extensive tumors, proximal tumors (to avoid esophageal anastomosis to the distal stomach remnant), and even palliation if necessary. Extending clear margins on a distal tumor by total rather than subtotal gastrectomy is of no benefit. Resections for linitis plastica are palliative, usually necessitate total gastrectomy, and are carried out to grossly negative margins only. Splenectomy is performed according to the location of gastric resection, but its routine performance does not improve the survival rate. The number of lymph nodes resected, the number of positive nodes, and the ratio of positive to the total number of lymph nodes have important staging implications. Furthermore, a minimum number of 15 lymph nodes should routinely be examined.
Answer
B
35 With regard to gastric volvulus, which of the following statements is true?
A Symptoms consist of severe nausea with an inability to vomit.
B The Borchardt triad includes acute epigastric pain, nausea, and bilious vomiting.
C It is frequently relieved simply by passage of a nasogastric tube.
D Gastric volvulus should always be managed conservatively.
E It is associated with an increased incidence of sigmoid volvulus.
Ref.: 1, 2
Comments
Gastric volvulus is a serious complication of paraesophageal hernia. Two types of gastric volvulus may occur, depending on the axis of rotation. Organoaxial volvulus, the more common type, involves rotation around the axis of a line connecting the cardia and pylorus. With mesenteroaxial volvulus, the axis is approximately at a right angle to the cardiopyloric line. Combined types have also been described. Patients generally have severe pain and nausea but are unable to vomit. Gastric volvulus should be suspected in patients with the Borchardt triad, which includes acute epigastric pain, violent retching, and inability to pass a nasogastric tube. Strangulation can follow. Hence, acute gastric volvulus requires prompt surgical intervention. It is not associated with an increased incidence of sigmoid volvulus.
Answer
A
36 With regard to GISTs, which of the following statements is incorrect?
A A combination of cellular morphology on hematoxylin-eosin staining and KIT immunohistochemistry are required for the diagnosis of GIST.
B After the small intestine, the stomach is the second most common location for GISTs, followed by the colon and rectum.
C The majority of GISTs have an activating mutation in the KIT oncogene.
D GISTs are usually resistant to conventional chemotherapy and radiation therapy.
E Complete surgical resection is the standard of treatment.
Ref.: 1, 8
Comments
Gastrointestinal stromal tumors are the most common mesenchymal neoplasms of the GI tract. The majority of these GISTs occur in the stomach (60%), followed by the small bowel (30%), esophagus (1% to 5%), and colon and rectum (5%). The diagnosis of GIST is based on the presence of characteristic pathologic findings on hematoxylin-eosin staining and expression of the KIT receptor on immunohistochemistry. Rarely, KIT might not be overexpressed, and in such cases molecular evaluation may be necessary. These tumors do not usually metastasize to lymph nodes. Complete surgical resection is the standard of treatment of primary, localized GISTs. The majority of GISTs have an activating mutation in the KIT protooncogene that can be effectively inhibited by tyrosine kinase inhibitors such as imatinib mesylate (Gleevec). GISTs are resistant to conventional chemoradiation therapy. Laparoscopic resection is increasingly being used, provided that clean margins can be obtained. Both the size and number of mitoses per 50 high-power field have been used to categorize tumor aggressiveness. Tumor location may have prognostic implications in that extragastric tumors may carry a worse prognosis. Large or unresectable tumors that show KIT overexpression may initially be treated with Gleevec.
Answer
B
37 Which of the following statements is not true regarding gastric MALT lymphoma?
A Gastric MALT lymphomas result from the monoclonal proliferation of B cells as a result of stimulation of a specific infecting strain of H. pylori.
B Unresponsive gastric MALT lymphoma can usually be salvaged by gastric resection.
C Chromosomal translocations and genetic mutations can predict failure of H. pylori treatment.
D Less than 10% of gastric lymphomas have no associated H. pylori infection.
E External beam radiation is used to treat refractory MALT lymphoma.
Ref.: 1, 6
Comments
Gastric MALT lymphoma is associated with chronic Helicobacter pylori infection in more than 90% of cases. This chronic infection with H. pylori results in monoclonal B-cell proliferation controlled by T lymphocytes. Treatment directed toward H. pylori eradication results in the resolution of MALT lymphomas in most cases. Certain chromosomal translocations and genetic mutations can predict resistance to H. pylori therapy and progression to a high-grade gastric lymphoma. Resistant gastric MALT lymphomas are usually salvaged with radiation therapy, cyclophosphamide-based chemotherapy regimens, monoclonal anti-CD20 antibody, or combinations of these treatments.
Answer
B
38 With regard to the diagnosis and treatment of MALT lymphoma, which of the following statements is correct?
A Upper GI endoscopy with gastric biopsy for determination of the presence of H. pylori and the histologic type of lymphoma is the diagnostic test of choice.
B Computed tomography of the abdomen, lymphangiography, chest radiography, and bone marrow biopsy are required for complete staging.
C H. pylori serology is sufficient to document remission.
D H. pylori–negative gastric MALT lymphoma should initially be treated with clarithromycin, amoxicillin, and a proton pump inhibitor.
E H. pylori Gram stain is sufficient to make the diagnosis alone.
Ref.: 1, 6
Comments
Upper endoscopy with biopsy is the diagnostic test of choice. Gastric biopsies are used to evaluate for the presence of H. pylori and the histologic type of lymphoma. The depth of gastric wall invasion and the presence of nodal involvement can be determined with the help of endoscopic ultrasonography. Staging is completed with a chest radiograph, bone marrow biopsy, and computed tomography of the abdomen. Lymphangiography is not required for staging. Surveillance is achieved with upper endoscopy, biopsy, and endoscopic ultrasound every 3 months until histologic and radiographic resolution. Complete resolution is usually achieved in 3 to 6 months on average. H. pylori–negative gastric MALT lymphoma, which accounts for less than 10% of all gastric lymphomas, does not respond to bacterial eradication therapy.
Answer
A
39 All of the following statements are correct about high-grade gastric lymphoma except:
A Treatment usually requires combination chemotherapy and radiation therapy.
B Randomized clinical trials for early stages IE and IIE disease demonstrate nonsurgical therapy to be equivalent or superior to surgical treatment in regard to patient survival.
C Hemorrhage is a frequent complication of chemotherapy.
D Surgical treatment is usually reserved for patients with localized persistent lymphoma or complications associated with nonsurgical treatment.
E Perforation is very rare after chemotherapy.
Ref.: 1, 6
Comments
High-grade gastric lymphomas require treatment with combination chemotherapy and the addition of radiation therapy for bulky or residual disease. Patient survival has been shown to be equivalent or better with nonsurgical treatment than with surgical treatment in several prospective clinical trials (randomized and nonrandomized). Complications were more frequent in the surgical groups than in the nonsurgical groups. Complications such as perforation and hemorrhage are very infrequent in patients undergoing chemotherapy or radiation therapy. Complications from chemoradiation therapy or persistent localized lymphoma are current indications for operative intervention in patients with gastric lymphoma.
Answer
C
40 A 23-year-old thin (92 lb) woman with a history of surgical correction of her scoliosis is evaluated for symptoms of postprandial epigastric pain, fullness, nausea, and vomiting. Her physical examination is unremarkable except for her thin physique/stature. Barium upper GI series showed a dilated duodenum and stomach with minimal flow of barium into the jejunum. Which of the following is the operative management of choice for this patient’s condition?
A Segmental duodenectomy
B Pancreaticoduodenectomy
C Gastrojejunostomy
D Duodenojejunostomy
E Roux-en-Y hepaticojejunostomy
Ref.: 1
Comments
The patient in this scenario has compression of the third portion of the duodenum by the superior mesenteric artery as it passes over it. This rare condition is known as superior mesenteric artery syndromeor Wilkie syndrome. This syndrome is usually seen in young asthenic females with predisposing conditions of weight loss, scoliosis or corrective surgery for it, supine mobilization, and placement of a body cast. The diagnosis is usually made with either a barium upper GI series or computed tomography, with oral and intravenous contrast enhancement demonstrating a dilated duodenum and stomach with abrupt or nearly complete cutoff of contrast agent at the third portion of the duodenum and minimal flow into the jejunum. Conservative management consisting of nutritional supplementation can be tried initially. In patients who fail medical management, the operative treatment of choice is duodenojejunostomy.
Answer
D
41 All of the following statements regarding Crohn’s disease of the duodenum are correct except:
A Duodenal Crohn’s disease accounts only for 2% to 4% of all patients with Crohn’s disease.
B Because of its location, operative intervention is frequently needed for duodenal Crohn’s disease.
C When an operation is required, a bypass such as gastrojejunostomy is performed rather than duodenal resection.
D In well-selected patients, strictureplasty can be carried out with good results.
E Adenocarcinoma is the leading cause of disease-specific death in patients with Crohn’s disease.
Ref.: 1, 9, 10
Comments
Crohn’s disease of the duodenum is not common and is seen in only 2% to 4% of patients with Crohn’s disease. Medical therapy remains the mainstay of treatment of duodenal Crohn’s disease, with surgical intervention being reserved for patients who do not respond to medical therapy or in whom a complication develops such as obstruction or perforation. In patients who do need a surgical procedure, bypass is preferred over duodenal resection. In a few select patients, their anatomy might be amenable to strictureplasty.
Irrespective of the location of Crohn’s disease, GI cancer remains the leading cause of death in patients with Crohn’s disease.
Answer
B
42 With regard to adenocarcinoma of the small bowel, all of the following statements are correct except:
A Small bowel adenocarcinoma is found in decreasing order of frequency in the ileum, jejunum, and duodenum.
B Villous adenomas of the small bowel are commonly found in the duodenum around the ampulla of Vater.
C Adenocarcinoma of the duodenum usually occurs earlier than small bowel adenocarcinoma elsewhere in the jejunum and ileum.
D Villous adenomas of the duodenum are frequently associated with familial adenomatous polyposis.
E Operative resection is the treatment modality of choice and has curative potential.
Ref.: 1, 2, 6
Comments
Small bowel adenocarcinoma accounts for the majority (35% to 50%) of small bowel malignant neoplasms, followed by carcinoid tumors, lymphomas, and sarcomas. Adenocarcinoma of the small bowel is more common in the duodenum, whereas carcinoid tumors and lymphoma are more frequently seen in the ileum. Small bowel adenocarcinoma is found in decreasing order of frequency in the duodenum, jejunum, and ileum. Although rare in the small bowel, villous adenomas are frequently found in the duodenum and are associated with familial adenomatous polyposis syndrome (31% to 92%). These villous adenomas have high malignant potential, especially if they are larger than 5 cm or are accompanied by bleeding or obstruction. Most patients have nonspecific symptoms initially; however, adenocarcinoma of the duodenum is manifested earlier with signs and symptoms of obstructive jaundice, gastric outlet obstruction, and abdominal pain. Operative resection (pancreaticoduodenectomy and local excision) is the treatment of choice, depending on the size and location of the adenocarcinoma, the patient’s health, and the surgeon’s expertise.
Answer
A
43 Concerning duodenal diverticula, all of the following statements are correct except:
A They are twice as common in women as in men.
B Duodenal diverticula are the second most common congenital diverticula of the intestine after Meckel diverticulum.
C The majority of duodenal diverticula are found in the periampullary region.
D Most of them are asymptomatic and found incidentally.
E They can result in cholangitis and pancreatitis from obstruction of the biliary or pancreatic ducts, respectively.
Ref.: 1
Comments
Duodenal diverticula are false diverticula containing only mucosa and submucosa, as opposed to a true diverticulum, which contains all layers of the intestinal wall (e.g., Meckel diverticulum). Duodenal diverticula are the second most common cause of acquired diverticula after those in the colon. They are more commonly seen in women than in men (2 : 1) and usually occur later in life, similar to colonic diverticula. The majority of these diverticula (≈75%) are found within a 2-cm radius from the ampulla of Vater and generally protrude through the medial wall of the duodenum. These duodenal diverticula are rarely symptomatic, and symptoms are usually the results of hemorrhage, perforation, blind loop syndrome, cholangitis, or pancreatitis from obstruction of the biliary or pancreatic ducts. Juxtapyloric diverticula have been noted to be associated with choledocholithiasis. Their presence increases the difficulty of successful completion of ERCP.
Answer
B
44 Which of the following is the preferred treatment of a symptomatic duodenal diverticulum?
A Observation
B Broad-spectrum antibiotics
C Duodenal diverticulectomy
D Pancreas-sparing duodenectomy
E Pancreaticoduodenectomy
Ref.: 1
Comments
As discussed earlier, most of the duodenal diverticula are asymptomatic and do not warrant any intervention. Surgery is reserved for patients in whom complications develop. They can cause abdominal pain, obstruction, perforation, bleeding, bacterial overgrowth, and pancreaticobiliary complications. When treatment is required, surgical excision (diverticulectomy) is recommended.
Answer
C
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