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Chapter 48 / Colon and Rectum 319

What is Cronkhite-Canada Diffuse GI hamartoma polyps (i.e., no syndrome? cancer potential) associated with

malabsorption/weight loss, diarrhea, and loss of electrolytes/protein; signs include alopecia, nail atrophy, skin pigmentation

What is Turcot’s syndrome? Colon polyps with malignant CNS tumors (glioblastoma multiforme)

DIVERTICULAR DISEASE OF THE COLON

DIVERTICULOSIS

What is diverticulosis? Condition in which diverticula can be found within the colon, especially the sigmoid; diverticula are actually false diverticula in that only mucosa and submucosa herniate through the bowel musculature; true diverticula involve all layers of the bowel wall and are rare in the colon

Diverticula

Blood vessel

Describe the pathophysiology. Weakness in the bowel wall develops at points where nutrient blood vessels enter between antimesenteric and mesenteric taeniae; increased intraluminal pressures then cause herniation through these areas

What is the incidence? 50% to 60% in the United States by age 60, with only 10% to 20% becoming symptomatic

What is the most common site?

95% of people with diverticulosis have sigmoid colon involvement

320 Section II / General Surgery

Who is at risk?

What are the symptoms/ complications?

What is the diagnostic approach:

Bleeding?

Pain and signs of inflammation?

What is the treatment of diverticulosis?

What are the indications for operation with diverticulosis?

People with low-fiber diets, chronic constipation, and a positive family history; incidence increases with age

Bleeding: may be massive

Diverticulitis, asymptomatic (80% of cases)

Without signs of inflammation: colonoscopy

Abdominal/pelvic CT scan

High-fiber diet is recommended

Complications of diverticulitis (e.g., fistula, obstruction, stricture); recurrent episodes; hemorrhage; suspected carcinoma; prolonged symptoms; abscess not drainable by percutaneous approach

When is it safe to get a colonoscopy or barium enema/sigmoidoscopy?

DIVERTICULITIS

Due to risk of perforation, this is performed 6 weeks after inflammation resolves to rule out colon cancer

What is it?

What is the pathophysiology?

What are the signs/ symptoms?

What are the associated lab findings?

What are the associated radiographic findings?

Infection or perforation of a diverticulum

Obstruction of diverticulum by a fecalith leading to inflammation and microperforation

LLQ pain (cramping or steady), change in bowel habits (diarrhea), fever, chills, anorexia, LLQ mass, nausea/vomiting, dysuria

Increased WBCs

On x-ray: ileus, partially obstructed colon, air-fluid levels, free air if perforated

On abdominal/pelvic CT scan: swollen, edematous bowel wall; particularly helpful in diagnosing an abscess

 

Chapter 48 / Colon and Rectum 321

What are the associated

Barium enema should be avoided in

barium enema findings?

acute cases

Is colonoscopy safe in an

No, there is increased risk of perforation

acute setting?

 

What are the possible

Abscess, diffuse peritonitis, fistula,

complications?

obstruction, perforation, stricture

What is the most common

Colovesical fistula (to bladder)

fistula with diverticulitis?

 

What is the best test for

CT scan

diverticulitis?

 

What is the initial therapy?

IV fluids, NPO, broad-spectrum

 

antibiotics with anaerobic coverage,

 

NG suction (as needed for emesis/ileus)

When is surgery warranted?

What is the lifelong risk of recurrence after:

First episode?

Second episode?

Obstruction, fistula, free perforation, abscess not amenable to percutaneous drainage, sepsis, deterioration with initial conservative treatment

33%

50%

What are the indications for elective resection?

What surgery is usually performed ELECTIVELY for recurrent bouts?

What type of surgery is usually performed for an acute case of diverticulitis with a complication (e.g., perforation, obstruction)?

Two episodes of diverticulitis; should be considered after the first episode in a young, diabetic, or immunosuppressed patient

One-stage operation: resection of involved segment and primary anastomosis (with preoperative bowel prep)

Hartmann’s procedure: resection of involved segment with an end colostomy and stapled rectal stump (will need subsequent reanastomosis of colon usually after 2–3 postoperative months)

322 Section II / General Surgery

 

What is the treatment of

Percutaneous drainage; if abscess is not

diverticular abscess?

amenable to percutaneous drainage, then

 

surgical approach for drainage is necessary

How common is massive

Very rare! Massive lower GI bleeding is

lower GI bleeding with

seen with diverticulosis, not diverticulitis

diverticulitis?

 

What are the most common

Diverticulosis (especially right sided),

causes of massive lower GI

vascular ectasia

bleeding in adults?

 

What must you rule out in

Colon cancer

any patient with diverticulitis/

 

diverticulosis?

 

COLONIC VOLVULUS

 

 

 

What is it?

Twisting of colon on itself about its

 

mesentery, resulting in obstruction and, if

 

complete, vascular compromise with

 

potential necrosis, perforation, or both

What is the most common

Sigmoid volvulus (makes sense because the

type of colonic volvulus?

sigmoid is a redundant/“floppy” structure!)

SIGMOID VOLVULUS

 

 

 

What is it?

Volvulus or “twist” in the sigmoid colon

 

Chapter 48 / Colon and Rectum 323

What is the incidence?

75% of colonic volvulus cases (Think:

 

Sigmoid Superior)

What are the etiologic

High-residue diet resulting in bulky stools

factors?

and tortuous, elongated colon; chronic

 

constipation; laxative abuse; pregnancy;

 

seen most commonly in bedridden elderly

 

or institutionalized patients, many of

 

whom have history of prior abdominal

 

surgery or distal colonic obstruction

What are the signs/

Acute abdominal pain, progressive

symptoms?

abdominal distention, anorexia,

 

obstipation, cramps, nausea/vomiting

What findings are evident

Distended loop of sigmoid colon, often in

on abdominal plain film?

the classic “bent inner tube” or “omega”

 

sign with the loop aiming toward the RUQ

What are the signs of necrotic

Free air, pneumatosis (air in bowel wall)

bowel in colonic volvulus?

 

How is the diagnosis made?

Sigmoidoscopy or radiographic exam with

 

gastrografin enema

Under what conditions is

If sigmoidoscopy and plain films fail to

gastrografin enema useful?

confirm the diagnosis; “bird’s beak” is

 

pathognomonic seen on enema contrast

 

study as the contrast comes to a sharp end

What are the signs of strangulation?

Discolored or hemorrhagic mucosa on sigmoidoscopy, bloody fluid in the rectum, frank ulceration or necrosis at the point of the twist, peritoneal signs, fever, hypotension, c WBCs

What is the initial treatment?

What is the percentage of recurrence after nonoperative reduction of a sigmoid volvulus?

Nonoperative: If there is no strangulation, sigmoidoscopic reduction is successful

in 85% of cases; enema study will occasionally reduce (5%)

40%!

324 Section II / General Surgery

What are the indications for Emergently if strangulation is suspected surgery? or nonoperative reduction unsuccessful

(Hartmann’s procedure); most patients should undergo resection during same hospitalization of redundant sigmoid after successful nonoperative reduction because of high recurrence rate (40%)

CECAL VOLVULUS

What is it?

What is a cecal “bascule” volvulus?

What is the incidence?

What is the etiology?

Twisting of the cecum upon itself and the mesentery

Instead of the more common axial

twist, the cecum folds upward (lies on the ascending colon)

25% of colonic volvulus (i.e., much less common than sigmoid volvulus)

Idiopathic, poor fixation of the right colon, many patients have history of abdominal surgery

What are the signs/

Acute onset of abdominal or colicky pain

symptoms?

beginning in the RLQ and progressing to

 

a constant pain, vomiting, obstipation,

 

abdominal distention, and SBO; many

 

patients will have had previous similar

 

episodes

How is the diagnosis made?

Abdominal plain film; dilated, ovoid

 

colon with large air/fluid level in the

 

RLQ often forming the classic “coffee

 

bean” sign with the apex aiming toward

 

the epigastrium or LUQ (must rule out

 

gastric dilation with NG aspiration)

What diagnostic studies

Water-soluble contrast study (gastrografin),

should be performed?

if diagnosis cannot be made by AXR

What is the treatment?

Emergent surgery, right colectomy with

 

primary anastomosis or ileostomy and

 

mucous fistula (primary anastomosis may

 

be performed in stable patients)

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