Abdominal Surgery: Small and Large Intestine Part II

Question 1

the formation of abnormal outpouchings of the colonic mucosa

Answer 1

Diverticula

Question 2

These can develop due to a combination of chronically elevated intraluminal pressures due to chronic constipation (e.g., due to low-fiber diets, lack of physical exercise) and age-related weakening of connective tissue.

Answer 2

Diverticula

Question 3

What contributes to the formation of diverticula?

Answer 3

These can develop due to a combination of chronically elevated intraluminal pressures due to chronic constipation (e.g., due to low-fiber diets, lack of physical exercise) and age-related weakening of connective tissue.

Question 4

What part of the GI tract is most involved in the formation of diverticula?

Answer 4

The sigmoid colon is most commonly involved.

Question 5

When is colonoscopy warranted in the evaluation of diverticula?

Answer 5

Colonoscopy is the diagnostic modality of choice for symptomatic diverticulosis but is contraindicated if acute inflammation of the diverticula (i.e., diverticulitis) is suspected.

Question 6

type of diverticulum that involves only the mucosa and submucosa and does not contain muscular layer or adventitia.

Answer 6

False diverticulum

Most common type of gastrointestinal diverticula
Typically acquired
particularly in the sigmoid colon

Question 7

The presence of multiple colonic diverticula without evidence of infection

Answer 7

Diverticulosis

Question 8

Contributing factors to diverticulosis

Answer 8

Diet (low-fiber, rich in fat and red meat)
Obesity
Low physical activity

Question 9

Is the most common cause of lower GI bleeding in adults.

Answer 9

Diverticulosis is the most common cause of lower GI bleeding in adults.

Question 10

________________is defined as the twisting of a loop of bowel on its mesentery and is one of the most common causes of intestinal obstruction but not the most common cause.

Answer 10

Volvulus

Question 11

How do patients with a volvulus typically present?

Answer 11

Patients typically show features of bowel obstruction (abdominal pain, distension, bilious vomiting) or of bowel ischemia and gangrene (tachycardia, hypotension, hematochezia, peritonitis) in severe cases

Question 12

__________________ is the investigation of choice in infants with suspected midgut volvulus

Answer 12

Upper GI series

A diagnostic imaging test which can be used to diagnose anatomic and/or functional abnormalities (e.g., strictures, dilatation) in the esophagus, stomach, and small intestines. A radiopaque fluid (e.g., barium or gastrografin) is swallowed and radiographs are taken to visualize the lumen of the alimentary tract.

Question 13

Ladd procedure

Answer 13

Surgical procedure to treat intestinal malrotation, consisting of division of Ladd’s bands, widening of the small intestinal mesentery, appendectomy, and correcting the location of cecum and colon.

Question 14

Surgical procedure to treat intestinal malrotation, consisting of division of Ladd’s bands, widening of the small intestinal mesentery, appendectomy, and correcting the location of cecum and colon.

Answer 14

Ladd procedure

Question 15

Volvulus of the ________________ is more common in infants while in __________________ is more common in adults

Answer 15

infants–> midgut
adults–> sigmoid

Question 16

What is the difference between intestinal alroation and a midgut volvulus?

Answer 16

Intestinal malrotation: arrest in the normal rotation of the gut in utero, resulting in an abnormal orientation of the bowel and mesentery within the abdominal cavity

Midgut volvulus: torsion of a malrotated midgut causing mechanical bowel obstruction, mostly in neonates and infants

Question 17

Pathophys of volvulus

Answer 17

Closed-loop mechanical bowel obstruction → accumulation of gas and feces within the loop → increased intraluminal pressure → impaired capillary perfusion of bowel → bowel strangulation, ischemia, and gangrene

Question 18

an abnormal rotation of the stomach of more than 180° → closed-loop obstruction → possible incarceration and strangulation → intestinal ischemia and perforation
Intestinal malrotation
Intestinal malrotation

Answer 18

Gastric volvulus

Question 19

Features of gastric volvulus

Answer 19

severe abdominal pain, retching, and inability to pass a nasogastric tube

Question 20

Signs of a midgut volvulus

Answer 20

Bilious vomiting with abdominal distension in a neonate/infant
Signs of bowel ischemia: hematochezia

Question 21

Corkscrew duodenum

Answer 21

Midgut volvulus on an upper GI series

Upper GI Series=A diagnostic imaging test which can be used to diagnose anatomic and/or functional abnormalities (e.g., strictures, dilatation) in the esophagus, stomach, and small intestines. A radiopaque fluid (e.g., barium or gastrografin) is swallowed and radiographs are taken to visualize the lumen of the alimentary tract.

Question 22

A radiologic sign characterized by a whorled appearance created by the twisting of one structure around another (e.g., from cecal volvulus, malrotation with midgut volvulus, ovarian torsion, testicular torsion). Can be seen on ultrasonography and CT scan.

Answer 22

Whirlpool sign, abdominal ultrasound will show this in a midgut volvulus

Question 23

What might we see with a brium enema in a midgut volvulus?

Answer 23

Bird’s beak sign at the site of the twist

Question 24

is the dilation of the colon in the absence of a mechanical obstruction (e.g., colonic tumor/stricture). There are three etiological types.

Answer 24

Megacolon

The 3 types: acute, chronic, and toxic megacolon

Question 25

Chronic megacolon is often caused by...

Answer 25

colonic dysmotility due to neuropathic or myopathic etiology Chronic megacolon is the permanent dilation of the colon caused by chronic colonic dysmotility due to an underlying neuropathic (Hirschsprung's disease, chronic Chagas disease) or myopathic (Duchenne's muscular dystrophy) disorder.

Question 26

Acute megacolon is seen in/caused by...

Answer 26

characteristically seen in severely medically/surgically ill patients, probably secondary to an electrolyte/metabolic imbalance

Question 27

How do we treat megacolon?

Answer 27

Patients with acute/chronic megacolon can often be treated conservatively with bowel rest, dietary modifications, prokinetic drugs, and/or neostigmine.

Question 28

When is surgical intervention warranted in acute/chronic megacolon?

Answer 28

Surgical intervention for acute/chronic megacolon (colectomy and ileorectal anastomosis) is indicated if conservative treatment fails.

Question 29

When is surgery indicated in toxic megacolon?

Answer 29

Conservative management of toxic megacolon includes bowel rest, IV antibiotics (for infectious colitis), IV steroids (for inflammatory bowel disease). There is a high risk of colonic perforation in patients with toxic megacolon. Hence, no improvement to medical therapy within 24–72 hours is an indication to perform surgery (subtotal colectomy and end ileostomy).

Question 30

Etiology of chronic megacolon

Answer 30

Congenital (e.g., Hirschsprung disease) Acquired: diabetic neuropathy Duchenne's muscular dystrophy Chronic Chagas disease

Question 31

Etiology of toxic megacolon?

Answer 31

Infectious colitis Bacterial: C. difficile (pseudomembranous colitis), Salmonella, Shigella, Campylobacter infections Ulcerative colitis, Crohn disease

Question 32

In which megacolon do we get loss of haustration observed on xray

Answer 32

Loss of haustration

Question 33

What are some differences in the clinical features of the megacolons?

Answer 33

Acute: constipation/diarrhea Chronic: constipation Toxic: bloody diarrhea

Question 34

How do patients with colonic polyps typically present?

Answer 34

Affected individuals are typically asymptomatic but may present with gastrointestinal (GI) bleeding, iron deficiency anemia, and/or mechanical bowel obstruction (e.g., due to intussusception)

Question 35

Colonic polyps are classified histologically as adenomatous (most common), hyperplastic, inflammatory, serrated, or hamartomatous. Which ones have the highest malignancy potential?

Answer 35

Adenomas (e.g., adenoma-carcinoma sequence) have the highest malignancy potential (∼ 5%).

Question 36

What subtype of adenomas have the highest malignant potential?

Answer 36

villous

Question 37

An autosomal dominant syndrome characterized by > 10 hamartomatous polyps throughout the gastrointestinal tract. Typically manifests within the first 2 decades of life with hematochezia. Patients have an increased risk of developing colorectal and/or gastric malignancies.

Answer 37

Juvenile polyposis syndrome

Question 38

An autosomal dominant, hamartomatous polyposis syndrome characterized by the presence of polyps (typically < 20) throughout the gastrointestinal tract (mainly the jejunum). Associated with mutation of the STK11 gene on chromosome 19p13.3. Manifests with hematochezia, constipation, diarrhea, mucocutaneous hyperpigmentation, and an increased risk of colorectal, ovarian, breast, and pancreatic cancer.

Answer 38

Peutz-Jeghers syndrome

Question 39

Polyps tend to be asymptomatic. If a patient has polyps, what might you expect to observe clinically?

Answer 39

Hematochezia Change in bowel habits Mucus in stool Pallor

Question 40

Hamartomatous polyposis syndromes

Answer 40

A subtype of hereditary polyposis syndrome. Characterized by hamartomatous polyps. Includes Peutz-Jeghers Syndrome (PJS), Juvenile polyposis syndrome (JPS), and PTEN-Hamartoma Tumor syndromes (PHTS).

Question 41

A subtype of hereditary polyposis syndromes. Characterized by numerous adenomatous polyps and an increased risk of colon cancer and other intestinal and extraintestinal tumors. Comprises classic familial adenomatous polyposis (FAP), FAP subtypes (e.g., Gardner syndrome, Turcot syndrome, attenuated FAP), and MUTYH-associated polyposis.

Answer 41

Adenomatous polyposis syndromes

Question 43

For pts with recurrent intussusception, what should we evaluate them for?

Answer 43

A pathologic lead point like a meckel diverticulum, a tumor, a polyp. The most common lead point is a Meckel Diverticulum so be astute if you see a patient with recurrent intussusception with iron deficiency/anemia (a sign of occult bleeding possible due to meckels).

Question 44

What are complications of diverticulitis?

Answer 44

Question 44

a 99m technetium scan/nuclear scintigraphy is the modality we use to evaluate...

Answer 44

meckel diverticulum

Question 44

What is the difference in approach for pts with asynmptomatic femoral hernias versus inguinal hernias?

Answer 44

Question 45

What are the different kinds of ascitic fluid characteristics?

Answer 45

Question 46

What is the typical appearance of ascitic fluid?

Answer 46

Straw-colored&clear

Question 47

What does bloody ascitic fluid indicate?

Answer 47

suggests trauma or malignancy

Question 48

What does cloudy ascitic fluid mean?

Answer 48

infection

Question 49

What does milky ascitic fluid indicate?

Answer 49

lymphatic disruption

Question 50

How could ordering a cell count and differential of ascitic fluid be helpful in dx?

Answer 50

Cell count can help narrow down somethings... Lymphocyte predominance indicates malignancy or tuberculosis while neutrophil predominance suggests spontaneous bacterial peritonitis

Question 51

Major risk factors for hepatocellular carcinoma

Answer 51

cirrhosis chronic hep B

Question 52

Elevated alpha fetoprotein in an adult male who has cirrhosis should raise concern for...

Answer 52

hepatocellular carcinoma

Question 53

What is severe acute pancreatitis?

Answer 53

defined as pancreatitis that causes failure of greater than or equal to one organ system lasting more than 48 hours.

Question 54

What are important clinical predictors of severe acute pancreatitis (associated with a worse prognosis)?

Answer 54

SIRS criteria, elevated BUN/signs of volume depletion due to third spacing, and radiologic signs of third spacing

Question 55

What is emphysematous cholecystitis?

Answer 55

A lifethreatening form of acute cholecystitis that occurs more commonly in patients with immunosuppression or vascular disease. It arises due to infection of gallbladder wall with gas-forming bacteria and requires emergency cystectomy.

Question 56

How is dx confirmed for emphysematous cholecystitis?

Answer 56

imaging demonstrating air fluid levels in the gall bladder, gas in the gall bladder wall, and occasionally pneumobilia.

Question 57

What is the next step in managment of a biliary cyst dx'd w/MRCP?

Answer 57

Surgery! There is a 30x increase in chance of malignancy so take that sucker out.

Question 58

What lab values should you look for in acute pancreatitis?

Answer 58

amylase/lipase levels >3 times the upper limit of normal

Question 59

55 yo m presenting with a year of progressive gatigue and frequenct loose stools. He describes voluminous foul smelling stools that are difficult to flush. He has lost about 20 pounds without trying this past year. On multiple occastions, he has been hospitalized for epigastric pain radiating to the back. What is this describing most likely?

Answer 59

Pancreatic insufficiency due to pancreatitis. Chronic pancreatitis can be due to alcohol abuse, cystic fibrosis, or autoimmune. Pancreatic cancer can also cause pancreatic insufficiency.

Question 60

What is the most likely caused of small bowel intestinal bleeding in a 10 yo boy?

Answer 60

meckel diverticulum, dx with t 99m scan

Question 61

Ischemic colitis commonly affects what watershed areas?

Answer 61

the splenic flexure and rectosigmoid junction

Question 62

How do we dx toxic megacolon?

Answer 62

ab ct, showing colonic dialation of greater than 6 cm

Question 63

How does the presentation of left vs right sided colon adenocarcinoma present?

Answer 63

Left: obstruction of the outflow of stool leading to altered bowel habits, hematochezia Right: bleeding is NOT likely visible so it has OCCULT bleeding and iron deficiency anemia Right is more insidious

Question 64

What do we mean by loss of haustrations on abdominal xray in the setting of toxic megacolon?

Answer 64

Question 65

Systemic toxicity presenting as fever, tachycardia, hypotension as well as ab pain and distention following a diarrheal illness or in suspected IBD is concerning for...

Answer 65

Toxic megacolon

Question 66

How do we treat toxic megacolon in an IBD pt?

Answer 66

Methyprednisolone! Fluids, electrolyte repletion, bowel rest and decompression (NG tube) and broad spec abx.

Question 67

What is the difference in presentation of a small bowel obstruction vs an ileus?

Answer 67

Question 68

How do we manage c. diff?

Answer 68

Question 69

DRE with bright red blood inthe rectum, colonoscopy with muscosal pallow, friability, and multiple telangienctasias in the setting of a pt with a hx of rdjuvant radiation therapy for cervical cancer is concerning for...

Answer 69

Radiation proctitis

Question 70

How might a SBO develop in a pt with crohn?

Answer 70

Severe uncontrolled inflammation can lead to fibrotic strictures

Question 71

How does abdominal compartment syndrome impact preload?

Answer 71

DECREASED preload (abdominal pressure decreases venous return to the heart)

Question 72

Abdominal distention, colonic dialation, in the setting of electrolyte derrangements or medications...

Answer 72

Acute colonic pseudo obstruction (ogilvie syndrome) arises from autonomic dysruption of the colon

Question 73

is the dilation of the colon in the absence of a mechanical obstruction (e.g., colonic tumor/stricture).

Answer 73

Megacolon

Question 74

etiological factors → impairment/destruction of the autonomic nervous system → imbalance between sympathetic and parasympathetic control of intestinal motility--> megacolon

Answer 74

Pathophysiology of acute megacolon (ogilvie's syndrome)

Question 75

What can contribute to acute megacolon? (acute colonic pseudoobstruction, ogilvie's syndrome)

Answer 75

Its idiopathic but can happen in the setting of very ill patients who recently underwent a surgical procedure, have electrolyte imbalances, or are on anticholinergic drugs, opioid analgesics, antipsychotics, calcium channel blockers

Question 76

What are the risk factors for toxic megacolon?

Answer 76

infections colitis as seen in c diff, UC, Crohns

Question 77

How may colonic polyps lead to bowel obstruction?

Answer 77

The polyps can cause intussusception

Question 78

Most common type of nonneoplastic polyp among those with low malignant potential, common in the distal colon

Answer 78

hyperplastic polyp

Question 79

red flags for CRC

Answer 79

change in bowel habits, lower GI bleeding, and weight loss. These features as well as iron deficiency anemia in men older than 50 years of age and postmenopausal women

Question 80

What labratory marker do we track in colorectal cancer?

Answer 80

CEA, which is a prognostic marker and should not be used to screen for colorectal cancer. Think of it as the CA125 of CRC.

Question 81

Lynch syndrome (hereditary nonpolyposis colorecta cancer) increases risk for what other kinds of cancer?

Answer 81

endometrial, gastric, and ovarian cancer.

Question 82

What criteria do we use to ID individuals at increased risk for lynch syndrome?

Answer 82

Amsterdam II criteria

Question 83

When is screening recommended for patients with family members who have lynch?

Answer 83

Preventative screening for colorectal cancer and associated tumors is recommended in individuals with family members known to have a Lynch syndrome gene mutation; it should occur every 1–2 years, starting at 20–25 years of age, or 2–5 years before the earliest recorded case of a tumor in the family.

Question 84

presence of Lynch syndrome-related CRC and brain tumors (especially gliomas)

Answer 84

Turcot syndrome

Question 85

What is the 3-2-1 rule with lynch syndrome?

Answer 85

3-2-1 rule: (3 affected family members, 2 generations, 1 relative under 50 years of age).

Question 86

How does the manifestation of familial adenmatous polyposis differ from lynch?

Answer 86

Lynch syndrome typically manifests with colorectal cancer of the proximal colon, with only a few adenomatous polyps, in contrast to familial adenomatous polyposis, in which hundreds of adenomatous polyps are present.

Question 87

painless rectal mass that protrudes through the anus Fecal incontinence Pruritus ani Rectal bleeding

Answer 87

rectal prolapse

Question 88

The main risk factors for developing anal cancer are ...

Answer 88

The main risk factors for developing anal cancer are immunosuppression and human papillomavirus (HPV) infection.

Question 89

This condition is the most common cause of lower gastrointestinal bleeding in adults.

Answer 89

Diverticulosis

Question 90

Tx of choice for anal SCC

Answer 90

The combination of chemotherapy and radiation is the treatment of choice for patients with anal canal SCC; it has been shown to be superior to surgery, with a 5-year survival rate of ∼ 80%. Subsequent surgery is only indicated if a residual tumor is confirmed with biopsy after the completion of radiochemotherapy.

Question 91

How does prophylaxis differ in pts with FAP versus lynch?

Answer 91

Patients with Lynch syndrome are at high risk of gastrointestinal malignancies and should receive an annual colonoscopy beginning at 20–25 years of age to screen for colorectal cancer, but prophylactic proctocolectomy is not recommended. Prophylactic subtotal or total proctocolectomy with ileoanal anastomosis is recommended in patients with familial adenomatous polyposis (FAP). A family history of gastrointestinal malignancy is also seen in FAP. However, patients with FAP would have numerous polyps on colonoscopy by adolescence, and germline testing would show a mutation in the adenomatous polyposis coli (APC) gene rather than in MLH1 and MSH2.

Question 92

Prophylactic proctocolectomy with ileoanal anastomosis is for...

Answer 92

Familial Adenomatous Polyposis

Question 93

Which is worse: villous or tubular adenomatous polyp

Answer 93

villous; A villous adenomatous polyp has the highest risk (∼ 50%) of malignant transformation of the three types of adenomatous polyps.

Question 94

An autosomal dominant, hamartomatous polyposis syndrome characterized by the presence of polyps (typically < 20) throughout the gastrointestinal tract (mainly the jejunum). Associated with mutation of the STK11 gene on chromosome 19p13.3. Manifests with hematochezia, constipation, diarrhea, mucocutaneous hyperpigmentation, and an increased risk of colorectal, ovarian, breast, and pancreatic cancer.

Answer 94

Peutz-Jeghers syndrome

Question 95

This patient presents with a protruding rectal polyp and multiple hamartomatous polyps. In combination with mucocutaneous hyperpigmentation, what is the most likely dx?

Answer 95

Peutz-Jeghers syndrome

Question 96

is a variant of familial adenomatous polyposis that manifests with multiple colonic polyps and may cause hematochezia together with extracolonic bone and/or soft tissue lesions, such as osteomas, epidermal cysts, and congenital hypertrophy of the retinal pigment epithelium, all of which are seen here. A family history of colon cancer at a young age furthermore supports this diagnosis.

Answer 96

Gardner Syndrome

Question 97

Conservative measures such as sitz baths and topical therapy with calcium channel blockers (e.g., nifedipine, diltiazem) are recommended as the initial treatment for most...

Answer 97

anal fissures

Question 98

What are the firstline Conservative measures for anal fissures?

Answer 98

Conservative measures such as sitz baths and topical therapy with calcium channel blockers (e.g., nifedipine, diltiazem) are recommended as the initial treatment for most anal fissures. These measures reduce anal sphincter tone and promote mucosal healing by increasing blood flow to the anal mucosa.

Question 99

Frank blood in stool and DRE shows no masses is concerning for...

Answer 99

likely diverticulosis