286 Section II / General Surgery
Why doesn’t an ileostomy or colostomy close?
Why doesn’t a gastrostomy close?
If the plastic tube, G-tube, or J-tube is removed, how fast can the hole to the stomach or jejunum close?
What is a “tube check”?
Epithelialization (mucosa to skin) from the acronym FRIEND (see page 305)
Foreign body (the plastic tube) from the acronym FRIEND
In a matter of hours! (Thus, if it comes out inadvertently from a well-established tract, it must be replaced immediately)
Gastrografin contrast study to confirm that a G-tube or J-tube is within the lumen of the stomach or jejunum, respectively
C h a p t e r 44 |
Small Intestine |
SMALL BOWEL |
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ANATOMY |
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What comprises the small |
Duodenum, jejunum, and ileum |
bowel? |
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How long is the duodenum? |
12 inches—thus the name: duodenum! |
What marks the end of the |
Ligament of Treitz |
duodenum and the start of |
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the jejunum? |
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What is the length of the entire small bowel?
What provides blood supply to the small bowel?
What does the small bowel do?
What are the plicae circulares?
6 meters (20 feet)
Branches of the superior mesenteric artery
Major site of digestion and absorption
Plicae means “folds,” circulares means “circular”; thus, circular folds of mucosa (a.k.a. valvulae conniventes) in small bowel lumen
Chapter 44 / Small Intestine 287
What are the major structural differences between the jejunum and the ileum?
Jejunum—long vasa rectae, large plicae circulares, thicker wall
Ileum—shorter vasa rectae, smaller plicae circulares, thinner wall (Think: Ileum Inferior vasa rectae,
Inferior plicae circulares, and Inferior wall thickness in comparison to the jejunum)
What does the terminal |
B12, fatty acids, bile salts |
ileum absorb? |
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SMALL BOWEL OBSTRUCTION |
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What is small bowel |
Mechanical obstruction to the passage of |
obstruction (SBO)? |
intraluminal contents |
What are the signs/ |
Abdominal discomfort, cramping, |
symptoms? |
nausea, abdominal distention, emesis, |
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high-pitched bowel sounds |
What lab tests are |
Electrolytes, CBC, type and screen, |
performed with SBO? |
urinalysis |
What are classic electrolyte/ |
Hypovolemic, hypochloremic, |
acid-base findings with |
hypokalemia, alkalosis |
proximal obstruction? |
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What must be ruled out on |
Incarcerated hernia (also look for surgical |
physical exam in patients |
scars) |
with SBO? |
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What major AXR findings |
Distended loops of small bowel air-fluid |
are associated with SBO? |
levels on upright film |
Air-fluid 
level
288 Section II / General Surgery |
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Define complete SBO. |
Complete obstruction of the lumen; |
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usually paucity or no colon gas |
What is the danger of |
Closed loop strangulation of the bowel |
complete SBO? |
leading to bowel necrosis |
Define partial SBO. |
Incomplete SBO; some colon gas |
What is initial management |
NPO, NGT, IVF, Foley |
of all patients with SBO? |
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What tests can differentiate |
CT with oral contrast, small bowel |
partial from complete bowel |
follow-through |
obstruction? |
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What are the ABCs of SBO? |
Causes of SBO: |
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1. Adhesions |
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2. Bulge (hernias) |
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3. Cancer and tumors |
What are other causes |
The acronym “GIVES BAD CRAMPS”: |
of SBO? |
Gallstone ileus |
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Intussusception |
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Volvulus |
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External compression |
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SMA syndrome |
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Bezoars, Bowel wall hematoma |
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Abscesses |
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Diverticulitis |
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Crohn’s disease |
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Radiation enteritis |
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Annular pancreas |
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Meckel’s diverticulum |
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Peritoneal adhesions |
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Stricture |
What is superior mesenteric |
Seen with weight loss—SMA compresses |
artery (SMA) syndrome? |
duodenum, causing obstruction |
What is the treatment of |
Laparotomy and lysis of adhesions |
complete SBO? |
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What is LOA? |
Lysis Of Adhesions |
What is the treatment of incomplete SBO?
Intraoperatively, how can the level of obstruction be determined in patients with SBO?
What is the most common indication for abdominal surgery in patients with Crohn’s disease?
Chapter 44 / Small Intestine 289
Initially, conservative treatment with close observation plus NGT decompression
Transition from dilated bowel proximal to the decompressed bowel distal to the obstruction
SBO
290 Section II / General Surgery |
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What is an absolute |
Peritoneal signs, free air on AXR |
indication for operation |
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with partial SBO? |
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What classic saying is |
“Never let the sun set or rise on complete |
associated with complete |
SBO” |
SBO? |
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What condition commonly |
Paralytic ileus (AXR reveals gas distention |
mimics SBO? |
throughout, including the colon) |
What is the differential |
Postoperative ileus after abdominal |
diagnosis of paralytic |
surgery (normally resolves in 3–5 days) |
(nonobstructive) ileus? |
Electrolyte abnormalities (hypokalemia is |
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most common) |
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Medications (anticholinergic, narcotics) |
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Inflammatory intra-abdominal process |
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Sepsis/shock |
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Spine injury/spinal cord injury |
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Retroperitoneal hemorrhage |
What tumor classically |
Carcinoid tumor |
causes SBO due to |
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“mesenteric fibrosis”? |
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SMALL BOWEL TUMORS
What is the differential diag- Leiomyoma, lipoma, lymphangioma,
nosis of benign tumors of |
fibroma, adenomas, hemangiomas |
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the small intestine? |
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What are the signs and |
Abdominal pain, weight loss, obstruction |
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symptoms of small bowel |
(SBO), and perforation |
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tumors? |
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What is the most common |
Leiomyoma |
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benign small bowel tumor? |
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What is the most common |
Adenocarcinoma |
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malignant small bowel tumor? |
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What is the differential |
1. |
Adenocarcinoma (50%) |
diagnosis of malignant |
2. |
Carcinoid (25%) |
tumors of the small |
3. |
Lymphoma (20%) |
intestine? |
4. |
Sarcomas ( 5%) |
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Chapter 44 / Small Intestine 291 |
What is the workup of a |
UGI with small bowel follow-through, |
small bowel tumor? |
enteroclysis, CT scan, enteroscopy |
What is the treatment for |
Resection and removal of mesenteric |
malignant small bowel |
draining lymph nodes |
tumor? |
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What malignancy is |
Melanoma |
classically associated with |
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metastasis to small bowel? |
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MECKEL’S DIVERTICULUM |
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What is it? |
Remnant of the omphalomesenteric duct/ |
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vitelline duct, which connects the yolk sac |
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with the primitive midgut in the embryo |
What is its claim to fame? |
Most common small bowel congenital |
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abnormality |
What is the usual location? |
Within 2 feet of the ileocecal valve on |
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the antimesenteric border of the bowel |
What is the major |
Appendicitis |
differential diagnosis? |
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Is it a true diverticulum? |
Yes; all layers of the intestine are found |
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in the wall |
What is the incidence? |
2% of the population at autopsy |
292 Section II / General Surgery |
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What is the gender ratio? |
Twice as common in men |
What is the average age at |
Most frequently in the first 2 years of |
onset of symptoms? |
life, but can occur at any age |
What are the possible |
Intestinal hemorrhage (painless)— |
complications? |
50%; accounts for half of all lower |
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GI bleeding in patients younger than |
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2 years |
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Bleeding results from ectopic gastric |
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mucosa secreting acid S ulcer S |
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bleeding |
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Intestinal obstruction—25%; most |
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common complication in adults; |
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includes volvulus and intussusception |
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Inflammation ( perforations)—20% |
What are the signs/ |
Lower GI bleeding, abdominal pain, SBO |
symptoms? |
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What is the most common |
Intestinal obstruction |
complication of Meckel’s |
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diverticulum in adults? |
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In what percentage of cases |
50% |
is heterotopic tissue found |
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in the diverticulum? |
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What heterotopic tissue type |
Gastric mucosa (60%), but duodenal, |
is most often found? |
pancreatic, and colonic mucosa are also |
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found |
What is the “rule of 2s”? |
2% of patients are symptomatic |
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Found 2 feet from the ileocecal valve |
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Found in 2% of the population |
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Most symptoms occur before age 2 years |
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Ectopic tissue found in 1 of 2 patients |
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Most diverticula are 2 inches long |
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2 to 1 male:female ratio |
What is the role of |
Most experts would remove in children |
incidental Meckel’s |
(very controversial in adults) |
diverticulectomy (surgical |
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removal upon finding |
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asymptomatic diverticulum)? |
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