Surgery: Small Bowel Obstruction High-Yield

Intra-abdominal adhesions (75%)

Approximately 3%

Obstipation (absence of stool and flatus)

Dilated small bowel >3 cm, air-fluid levels, and paucity of colonic gas

At least 3 air-fluid levels

U-shaped or C-shaped dilated loops with converging mesenteric vessels

Bowel wall thickening, pneumatosis intestinalis, portal venous gas, and poor contrast enhancement

IV fluids, electrolyte correction, NPO, and NGT decompression

Failed conservative treatment or signs of strangulation

Abdominal surgery and bowel manipulation

Ileus has diminished bowel sounds; SBO has hyperactive, high-pitched sounds

24 hours

48 hours

2–5 days

Passage of flatus or bowel movement

Chronic idiopathic transmural inflammatory disease that can affect any part of the GIT

Distal ileum (75%)

Skip lesions

All bowel wall layers (transmural)

Cobblestoning

Aphthous ulcers

Creeping fat (fat wrapping)

ASCA positive, pANCA negative

Non-caseating granulomas

Ileocolonoscopy

Caseating granulomas

Segmental resection with end-to-end anastomosis

Widening a narrowed intestinal lumen without bowel resection

Short strictures less than 12 cm

Longer strictures up to 25 cm

Abscess or fistula

Less than 200 mL/day

More than 500 mL/day

Enterocutaneous fistula

Iatrogenic injury

Foreign body, Radiation, Infection, Epithelialization, Neoplasm, Distal obstruction, Short tract

CT scan

Fistulogram

Stabilization, sepsis control, nutrition, and output control

Octreotide

Adenoma

Villous adenoma

Adenocarcinoma

Duodenum

Gastrointestinal stromal tumor (GIST)

Interstitial cells of Cajal

Segmental resection without lymphadenectomy

Imatinib (Gleevec)

Intestinal lymphoma

Terminal ileum, particularly Peyer's patches

Ileum (appendix is the most common overall GI site)

Systemic release of serotonin and other mediators, usually with liver metastases

Flushing, diarrhea, hypotension, and tachycardia

Octreotide

True diverticulum caused by incomplete obliteration of the vitelline duct

8th week

Antimesenteric ileum, approximately 2 feet from the ileocecal valve

2% prevalence, 2:1 male predominance, 2 feet from ileocecal valve, 2 inches long, symptomatic before age 2

Tc-99m pertechnetate scan

Bleeding

Intestinal obstruction

False diverticulum containing mucosa and submucosa without muscularis propria

Duodenum, particularly periampullary

Enteroclysis

Sudden reduction in intestinal blood supply causing bowel ischemia and possible infarction

Arterial embolism

Cardiac emboli

CT scan

Angiography

Mesenteric vasospasm without mechanical vascular obstruction

Papaverine

Superior mesenteric vein

Presence of gas within the bowel wall

Residual small bowel less than 200 cm with significant malabsorption

Vitamin B12

Terminal ileum

Nutritional support, including TPN when necessary

Telescoping of one bowel segment into another

Ileocolic

Target or donut sign

Empty right lower quadrant due to intussusception

Hydrostatic reduction

Compression of the third portion of the duodenum between the SMA and aorta

Less than 22°

Less than 8 mm

Intestinal injury caused by radiation exposure

At least 4,500 cGy

Accumulation of triglyceride-rich, milky lymphatic fluid in the peritoneal cavity

Paracentesis

Lymphangiography

Approximately 4–6 meters

Duodenum, jejunum, and ileum

Duodenum

Approximately 25–30 cm

Ligament of Treitz

Jejunum

Ileum

Ileum

Jejunum

Ileum

Enterocyte

Goblet cells

Paneth cells

M cells

Submucosa

Between the circular and longitudinal muscle layers

Regulation of peristalsis

Regulation of mucosal secretion and vascular tone

SGLT1

GLUT5

Terminal ileum, bound to intrinsic factor

Cholecystokinin (CCK)

Secretin

Motilin

Peptide YY

GLP-2

A narrow, blind-ended tubular organ arising from the cecum

At the convergence of the three taeniae coli

Approximately 6–9 cm

Luminal obstruction, commonly by a fecalith

Lymphoid hyperplasia

Obstruction, congestion, suppuration, and gangrene/necrosis

C fibers

Periumbilical region

A-delta fibers

Right lower quadrant

Escherichia coli

Bacteroides

Point approximately one-third of the distance from the right ASIS to the umbilicus

Left lower quadrant pressure produces right lower quadrant pain

Pain with resisted right hip flexion or extension

Pelvic appendix irritation

Increased abdominal pain with coughing

10 points

2 points

2 points

9–10 points

History and physical examination

Serum beta-hCG

Appendectomy

Inflammation of residual appendiceal tissue after appendectomy

Carcinoid (neuroendocrine tumor)

Right hemicolectomy

Peritonitis, periappendiceal abscess, and phlegmon

Functional division of the liver following the middle hepatic vein

Gallbladder fossa and inferior vena cava

Surface anatomical landmark separating the apparent right and left liver lobes

Middle hepatic vein

Liver

1,200–1,500 g

Glisson's capsule

Portal vein, hepatic artery, and bile duct

Temporary clamping of the hepatoduodenal ligament to control hepatic inflow

25%

Hepatic artery dilation when portal venous flow decreases

Caudate lobe

Segments II and III

Segment IV

Segments V and VIII

Segments VI and VII

Directly into the inferior vena cava

Middle hepatic vein

Ligamentum teres

Ligamentum venosum

Glycogen storage and glucose regulation

Phagocytosis of microorganisms and debris

Metabolism, detoxification, and bile production

Hepatocellular injury

Hepatocellular injury, but it is less liver-specific than ALT

Elevated alkaline phosphatase and GGT

Albumin and prothrombin time/INR

Conjugated hyperbilirubinemia, often from impaired excretion

Acute severe hepatic dysfunction with coagulopathy and encephalopathy in a patient without established cirrhosis

Drug-induced injury, viral hepatitis, and other severe hepatic insults

Assessment of cirrhosis severity and prognosis

Bilirubin, albumin, INR/PT, ascites, and encephalopathy

5–6

7–9

10–15

Assessment of end-stage liver disease and transplant prioritization

Increased pressure within the portal venous system

Cirrhosis

Variceal hemorrhage

Esophageal, gastric, rectal, and paraumbilical regions

Vasoactive therapy such as octreotide

Endoscopic variceal ligation

TIPS (transjugular intrahepatic portosystemic shunt)

Primary malignancy arising from hepatocytes

Cirrhosis

Alpha-fetoprotein (AFP)

Single tumor ≤5 cm or up to three tumors each ≤3 cm, without gross vascular invasion or extrahepatic spread

Cholesterol supersaturation of bile

Cholesterol stones and pigment stones

Gallstones

Greater than 3 cm

Right upper quadrant pain, fever, and positive Murphy's sign

Inspiratory arrest caused by pain during palpation of the right upper quadrant

Right upper quadrant ultrasonography

Supportive care, antibiotics when indicated, and early cholecystectomy

Identification of only two structures entering the gallbladder before division

An anatomical space used to identify the cystic artery and related structures during cholecystectomy

Presence of gallstones within the common bile duct

Obstructive jaundice

ERCP

RUQ pain, fever, and jaundice

Charcot's triad plus hypotension and altered mental status

Infection of the biliary tree associated with biliary obstruction

Biliary drainage, commonly through ERCP, alongside supportive care and antibiotics

Mechanical intestinal obstruction caused by a gallstone entering the bowel through a biliary-enteric fistula

Gastric outlet obstruction caused by an impacted gallstone near the pylorus or duodenum

Congenital cystic dilatation of the extrahepatic and/or intrahepatic bile ducts

Jaundice, abdominal pain, and palpable abdominal mass

Surgical excision of the affected extrahepatic biliary tree with biliary reconstruction

Painless obstructive jaundice

Perihilar cholangiocarcinoma involving the hepatic duct confluence

Bismuth-Corlette classification

Distal colon and rectosigmoid region

Increasing age

Approximately 80%

Approximately 20%

Change in bowel habits

Occult bleeding and iron-deficiency anemia

Altered bowel habits and intestinal obstruction

FAP and Lynch syndrome

Autosomal dominant disorder characterized by hundreds to thousands of colorectal adenomas

APC gene

Nearly 100%

A milder form with approximately 10–100 adenomas, often right-sided

Hereditary nonpolyposis colorectal cancer caused by mismatch repair gene defects

MLH1, MSH2, MSH6, PMS2, and EPCAM

FAP associated with osteomas, epidermoid cysts, and supernumerary teeth

Lynch-associated syndrome with sebaceous tumors and internal malignancies

Hamartomatous polyposis with mucocutaneous pigmentation

Hereditary hamartomatous polyposis characterized by numerous juvenile polyps

Endoscopic polypectomy

Depth of invasion in pedunculated malignant colorectal polyps

Depth of submucosal invasion in sessile malignant colorectal polyps

Tumor extent, lymph node involvement, and distant metastasis

Complete removal of the rectum and surrounding mesorectal tissue

Radial margin surrounding the rectal tumor and mesorectal specimen

Pelvic MRI

CEA

Abdominoperineal resection

Permanent end colostomy

Removal of the right colon with associated lymphovascular drainage

Ulcerative colitis

Continuous mucosal inflammation beginning in the rectum

Mucosa and submucosa

Crohn's has skip lesions; ulcerative colitis has continuous disease

Ulcerative colitis

Engorgement of mesenteric vasa recta

Presence of colonic diverticula

Inflammation of colonic diverticula

Sigmoid colon

Posterior midline

Severe tearing pain during defecation

Stool softeners, fiber, hydration, and warm sitz baths

Lateral internal sphincterotomy

Above the dentate line

Below the dentate line

Painless bright-red rectal bleeding

They are covered by somatically innervated anoderm

Grade I no prolapse; II spontaneous reduction; III manual reduction; IV irreducible

Hemorrhoidectomy when indicated

Compression causes hemorrhoidal tissue necrosis and subsequent sloughing

Localized collection of pus in the anorectal spaces

Surgical drainage

Abnormal tract connecting the anal canal to perianal skin

Anterior external openings usually follow a straight tract; posterior openings usually curve to the posterior midline

Necrotizing infection of the perineal and genital fascia

Urgent surgical debridement and broad-spectrum antibiotics

Hair-containing sinus or abscess in the intergluteal cleft

End ileostomy (Brooke)

Through the rectus muscle and below the belt line

Wirsung's duct

Santorini's duct

Major duodenal papilla

Minor duodenal papilla

Secretion of digestive enzymes and bicarbonate

Regulation of blood glucose through islet hormones

Beta cells

Alpha cells

Delta cells

PP cells

Acute inflammation of the pancreas

Gallstones and alcohol

Severe epigastric pain radiating to the back

Serum lipase

Serum lipase/amylase at least three times normal and characteristic abdominal pain

Assessment of acute pancreatitis severity and prognosis

Early severity and mortality risk assessment in acute pancreatitis

Severe hemorrhagic pancreatitis

Periumbilical ecchymosis

Flank ecchymosis

IV fluid resuscitation, analgesia, and appropriate nutritional support