Colon and Rectum, C48 P308-325 Flashcards
ANATOMY
Identify the arterial blood supply to the colon:
P308 (picture)
- Ileocolic artery
- Right colic artery
- Superior mesenteric artery (SMA)
- Middle colic artery
- Inferior mesenteric artery (IMA)
- Left colic artery
- Sigmoidal artery
- Superior hemorrhoidal artery
(superior rectal) - Middle hemorrhoidal artery
10 Inferior hemorrhoidal artery - Marginal artery of Drummond
- Meandering artery of Gonzalez
ANATOMY
What are the white lines of
Toldt?
P309
Lateral peritoneal reflections of the
ascending and descending colon
ANATOMY
What parts of the GI tract
do not have a serosa?
P309
Esophagus, middle and distal rectum
ANATOMY What are the major anatomic differences between the colon and the small bowel? P309
Colon has taeniae coli, haustra, and appendices epiploicae (fat appendages), whereas the small intestine is smooth
ANATOMY What is the blood supply to the rectum: Proximal? P309
Superior hemorrhoidal (or superior rectal) from the IMA
ANATOMY What is the blood supply to the rectum: Middle? P309
Middle hemorrhoidal (or middle rectal) from the hypogastric (internal iliac)
ANATOMY What is the blood supply to the rectum: Distal? P309
Inferior hemorrhoidal (or inferior rectal)
from the pudendal artery (a branch of
the hypogastric artery)
ANATOMY What is the venous drainage of the rectum: Proximal? P309
Via the IMV to the splenic vein, then to
the portal vein
ANATOMY What is the venous drainage of the rectum: Middle? P309
Via the iliac vein to the IVC
ANATOMY What is the venous drainage of the rectum: Distal? P309
Via the iliac vein to the IVC
COLORECTAL CARCINOMA
What is it?
P309
Adenocarcinoma of the colon or rectum
COLORECTAL CARCINOMA
What is the incidence?
P309
Most common GI cancer Second most common cancer in the United States Incidence increases with age starting at 40 and peaks at 70 to 80 years
COLORECTAL CARCINOMA
How common is it as a cause
of cancer deaths?
P309
Second most common cause of cancer
deaths
COLORECTAL CARCINOMA
What is the lifetime risk of
colorectal cancer?
P310
6%
COLORECTAL CARCINOMA
What is the male to female
ratio?
P310
≈1:1
COLORECTAL CARCINOMA
What are the risk factors?
P310
Dietary: Low-fiber, high-fat diets correlate with increased rates Genetic: Family history is important when taking history FAP, Lynch’s syndrome IBD: Ulcerative colitis > Crohn’s disease, age, previous colon cancer
COLORECTAL CARCINOMA
What is Lynch’s syndrome?
P310
HNPCC = Hereditary NonPolyposis
Colon Cancer—autosomal-dominant
inheritance of high risk for development
of colon cancer
COLORECTAL CARCINOMA What are current ACS recommendations for polyp/colorectal screening in asymptomatic patients without family (first-degree) history of colorectal cancer? P310
Starting at age 50, at least one of the following test regimens is recommended: Colonoscopy q 10 yrs Double contrast barium enema (DCBE) q 5 yrs Flex sigmoidoscopy q 5 yrs CT colonography q 5 yrs
COLORECTAL CARCINOMA What are the current recommendations for colorectal cancer screening if there is a history of colorectal cancer in a first-degree relative less than 60 years old? P310
Colonoscopy at age 40, or 10 years before
the age at diagnosis of the youngest
first-degree relative, and every 5 years
thereafter
COLORECTAL CARCINOMA What percentage of adults will have a guaiac-positive stool test? P310
≈2%
COLORECTAL CARCINOMA What percentage of patients with a guaiac-positive stool test will have colon cancer? P310
≈10%
COLORECTAL CARCINOMA What signs/symptoms are associated with the following conditions: Right-sided lesions? P311
Right side of bowel has a large luminal diameter, so a tumor may attain a large size before causing problems Microcytic anemia, occult/melena more than hematochezia PR, postprandial discomfort, fatigue
COLORECTAL CARCINOMA What signs/symptoms are associated with the following conditions: Left-sided lesions? P311
Left side of bowel has smaller lumen and semisolid contents Change in bowel habits (small-caliber stools), colicky pain, signs of obstruction, abdominal mass, heme() or gross red blood Nausea, vomiting, constipation
COLORECTAL CARCINOMA
From which site is melena
more common?
P311
Right-sided colon cancer
COLORECTAL CARCINOMA From which site is hematochezia more common? P311
Left-sided colon cancer
COLORECTAL CARCINOMA
What is the incidence of
rectal cancer?
P311
Comprises 20% to 30% of all colorectal
cancer
COLORECTAL CARCINOMA
What are the signs/
symptoms of rectal cancer?
P311
Most common symptom is hematochezia
(passage of red blood ± stool) or mucus;
also tenesmus, feeling of incomplete
evacuation of stool (because of the mass),
and rectal mass
COLORECTAL CARCINOMA What is the differential diagnosis of a colon tumor/ mass? P311
Adenocarcinoma, carcinoid tumor, lipoma,
liposarcoma, leiomyoma, leiomyosarcoma,
lymphoma, diverticular disease, ulcerative
colitis, Crohn’s disease, polyps
COLORECTAL CARCINOMA
Which diagnostic tests are
helpful?
P311
History and physical exam (Note: 10%
of cancers are palpable on rectal
exam), heme occult, CBC, barium
enema, colonoscopy
COLORECTAL CARCINOMA What disease does microcytic anemia signify until proven otherwise in a man or postmenopausal woman? P312
Colon cancer
COLORECTAL CARCINOMA
What tests help find
metastases?
P312
CXR (lung metastases), LFTs (liver metastases), abdominal CT (liver metastases), other tests based on history and physical exam (e.g., head CT for left arm weakness looking for brain metastasis)
COLORECTAL CARCINOMA What is the preoperative workup for colorectal cancer? P312
History, physical exam, LFTs, CEA, CBC,
Chem 10, PT/PTT, type and cross 2 u
PRBCs, CXR, U/A, abdominopelvic CT
COLORECTAL CARCINOMA
What are the means by
which the cancer spreads?
P312
Direct extension: circumferentially and then through bowel wall to later invade other abdominoperineal organs Hematogenous: portal circulation to liver; lumbar/vertebral veins to lungs Lymphogenous: regional lymph nodes Transperitoneal Intraluminal
COLORECTAL CARCINOMA
Is CEA useful?
P312
Not for screening but for baseline and
recurrence surveillance (but offers no
proven survival benefit)
COLORECTAL CARCINOMA What unique diagnostic test is helpful in patients with rectal cancer? P312
Endorectal ultrasound (probe is placed
transanally and depth of invasion and
nodes are evaluated)
COLORECTAL CARCINOMA
How are tumors staged?
P312
TMN staging system
COLORECTAL CARCINOMA
Give the TNM stages:
Stage I
P312
Invades submucosa or muscularis propria
T1–2 N0 M0
COLORECTAL CARCINOMA
Give the TNM stages:
Stage II
P312
Invades through muscularis propria or
surrounding structures but with negative
nodes (T3–4, N0, M0)
COLORECTAL CARCINOMA
Give the TNM stages:
Stage III
P313
Positive nodes, no distant metastasis
any T, N1–3, M0
COLORECTAL CARCINOMA
Give the TNM stages:
Stage IV
P313
Positive distant metastasis (any T, any
N, M1)
COLORECTAL CARCINOMA What is the approximate 5-year survival by stage: Stage I? P313
90%
COLORECTAL CARCINOMA What is the approximate 5-year survival by stage: Stage II? P313
70%
COLORECTAL CARCINOMA What is the approximate 5-year survival by stage: Stage III? P313
50%
COLORECTAL CARCINOMA What is the approximate 5-year survival by stage: Stage IV? P313
10%
COLORECTAL CARCINOMA What percentage of patients with colorectal cancer have liver metastases on diagnosis? P313
≈20%
COLORECTAL CARCINOMA
Define the preoperative
“bowel prep.”
P313
Preoperative preparation for colon/rectal resection: 1. Golytely colonic lavage or Fleets Phospho-Soda until clear effluent per rectum 2. PO antibiotics (1 gm neomycin and 1 gm erythromycin 3 doses) Note: Patient should also receive preoperative and 24-hr IV antibiotics
COLORECTAL CARCINOMA What are the common preoperative IV antibiotics? P313
Cefoxitin, Unasyn®
COLORECTAL CARCINOMA If the patient is allergic (hives, swelling), what antibiotics should be prescribed? P313
IV Cipro® and Flagyl®
COLORECTAL CARCINOMA
What are the treatment
options?
P313
Resection: wide surgical resection of
lesion and its regional lymphatic drainage
COLORECTAL CARCINOMA What decides low anterior resection (LAR) versus abdominal perineal resection (APR)? P314
Distance from the anal verge, pelvis size
COLORECTAL CARCINOMA
What do all rectal cancer
operations include?
P314
Total mesorectal excision—remove the
rectal mesentery, including the lymph
nodes (LNs)
COLORECTAL CARCINOMA
What is the lowest LAR
possible?
P314
Coloanal anastomosis (anastomosis normal colon directly to anus)
COLORECTAL CARCINOMA What do some surgeons do with any anastomosis less than 5 cm from the anus? P314
Temporary ileostomy to “protect” the
anastomosis
COLORECTAL CARCINOMA What surgical margins are needed for colon cancer? P314
Traditionally >5 cm; margins must be at
least 2 cm
COLORECTAL CARCINOMA
What is the minimal surgical
margin for rectal cancer?
P314
2 cm
COLORECTAL CARCINOMA How many lymph nodes should be resected with a colon cancer mass? P314
12 LNs minimum = for staging, and may
improve prognosis
COLORECTAL CARCINOMA What is the adjuvant treatment of stage III colon cancer? P314
5-FU and leucovorin (or levamisole)
chemotherapy (if there is nodal
metastasis postoperatively)
COLORECTAL CARCINOMA What is the adjuvant treatment for T3–T4 rectal cancer? P314
Preoperative radiation therapy and
5-FU chemotherapy as a “radiosensitizer”
COLORECTAL CARCINOMA What is the most common site of distant (hematogenous) metastasis from colorectal cancer? P314
Liver
COLORECTAL CARCINOMA What is the treatment of liver metastases from colorectal cancer? P314
Resect with ≥1-cm margins and
administer chemotherapy if feasible
COLORECTAL CARCINOMA
What is the surveillance
regimen?
P315
Physical exam, stool guaiac, CBC, CEA, LFTs (every 3 months for 3 years, then every 6 months for 2 years), CXR every 6 months for 2 years and then yearly, colonoscopy at years 1 and 3 postoperatively, CT scans directed by exam
COLORECTAL CARCINOMA Why is follow-up so important the first 3 postoperative years? P315
≈90% of colorectal recurrences are
within 3 years of surgery
COLORECTAL CARCINOMA What are the most common causes of colonic obstruction in the adult population? P315
Colon cancer, diverticular disease,
colonic volvulus
COLORECTAL CARCINOMA What is the 5-year survival rate after liver resection with clean margins for colon cancer liver metastasis? P315
≈33% (28%–50%)
COLORECTAL CARCINOMA What is the 5-year survival rate after diagnosis of unresectable colon cancer liver metastasis? P315
0%
COLONIC AND RECTAL POLYPS
What are they?
P315
Tissue growth into bowel lumen, usually
consisting of mucosa, submucosa, or both
COLONIC AND RECTAL POLYPS
How are they anatomically
classified?
P315
Sessile (flat)
Pedunculated (on a stalk)
COLONIC AND RECTAL POLYPS What are the histologic classifications of the following types: Inflammatory (pseudopolyp)? P315
As in Crohn’s disease or ulcerative colitis
COLONIC AND RECTAL POLYPS What are the histologic classifications of the following types: Hamartomatous? P315
Normal tissue in abnormal configuration
COLONIC AND RECTAL POLYPS What are the histologic classifications of the following types: Hyperplastic? P315
Benign—normal cells—no malignant
potential
COLONIC AND RECTAL POLYPS What are the histologic classifications of the following types: Neoplastic? P316
Proliferation of undifferentiated cells;
premalignant or malignant cells
COLONIC AND RECTAL POLYPS
What are the subtypes of
neoplastic polyps?
P316
Tubular adenomas (usually pedunculated)
Tubulovillous adenomas
Villous adenomas (usually sessile and look
like broccoli heads)
COLONIC AND RECTAL POLYPS What determines malignant potential of an adenomatous polyp? P316
Size
Histologic type
Atypia of cells
COLONIC AND RECTAL POLYPS What is the most common type of adenomatous polyp? P316
Tubular 85%
COLONIC AND RECTAL POLYPS What is the correlation between size and malignancy? P316
Polyps larger than 2 cm have a high risk of carcinoma (33%–55%)
COLONIC AND RECTAL POLYPS What about histology and cancer potential of an adenomatous polyp? P316
Villous > tubovillous > tubular (Think:
VILLous = VILLain)
COLONIC AND RECTAL POLYPS What is the approximate percentage of carcinomas found in the following polyps overall: Tubular adenoma? P316
5%
COLONIC AND RECTAL POLYPS What is the approximate percentage of carcinomas found in the following polyps overall: Tubulovillous adenoma? P316
20%
COLONIC AND RECTAL POLYPS What is the approximate percentage of carcinomas found in the following polyps overall: Villous adenoma? P316
40%
COLONIC AND RECTAL POLYPS
Where are most polyps found?
P316
Rectosigmoid (30%)
COLONIC AND RECTAL POLYPS
What are the signs/symptoms?
P316
Bleeding (red or dark blood), change in
bowel habits, mucus per rectum,
electrolyte loss, totally asymptomatic
COLONIC AND RECTAL POLYPS
What are the diagnostic tests?
P316
Best = colonoscopy
Less sensitive for small polyps = barium
enema and sigmoidoscopy
COLONIC AND RECTAL POLYPS
What is the treatment?
P317
Endoscopic resection (snared) if polyps;
large sessile villous adenomas should be
removed with bowel resection and lymph
node resection
POLYPOSIS SYNDROMES FAMILIAL POLYPOSIS What is another name for this condition? P317
Familial adenomatous polyposis (FAP)
POLYPOSIS SYNDROMES
FAMILIAL POLYPOSIS
What are the characteristics?
P317
Hundreds of adenomatous polyps within
the rectum and colon that begin developing
at puberty; all undiagnosed; untreated
patients develop cancer by ages 40 to 50
POLYPOSIS SYNDROMES FAMILIAL POLYPOSIS What is the inheritance pattern? P317
Autosomal dominant (i.e., 50% of offspring)
POLYPOSIS SYNDROMES
FAMILIAL POLYPOSIS
What is the genetic defect?
P317
APC (adenomatous polyposis coli) gene
POLYPOSIS SYNDROMES
FAMILIAL POLYPOSIS
What is the treatment?
P317
Total proctocolectomy and ileostomy
Total colectomy and rectal mucosal
removal (mucosal proctectomy) and
ileoanal anastomosis
POLYPOSIS SYNDROMES GARDNER’S SYNDROME What are the characteristics? P317
Neoplastic polyps of the small bowel
and colon; cancer by age 40 in 100% of
undiagnosed patients, as in FAP
POLYPOSIS SYNDROMES GARDNER’S SYNDROME What are the other associated findings? P317
Desmoid tumors (in abdominal wall or
cavity), osteomas of skull (seen on x-ray),
sebaceous cysts, adrenal and thyroid
tumors, retroperitoneal fibrosis, duodenal
and periampullary tumors
POLYPOSIS SYNDROMES GARDNER’S SYNDROME How can the findings associated with Gardner’s syndrome be remembered? P317
Think of a gardener planting “SOD”:
Sebaceous cysts
Osteomas
Desmoid tumors
POLYPOSIS SYNDROMES
GARDNER’S SYNDROME
What is a desmoid tumor?
P318
Tumor of the musculoaponeurotic sheath,
usually of the abdominal wall; benign, but
grows locally; treated by wide resection
POLYPOSIS SYNDROMES GARDNER’S SYNDROME What medications may slow the growth of a desmoid tumor? P318
Tamoxifen, sulindac, steroids
POLYPOSIS SYNDROMES GARDNER’S SYNDROME What is the inheritance pattern? P318
Varying degree of penetrance from an
autosomal-dominant gene
POLYPOSIS SYNDROMES GARDNER’S SYNDROME What is the treatment of colon polyps in patients with Gardner’s syndrome? P318
Total proctocolectomy and ileostomy
Total colectomy and rectal mucosal
removal (mucosal proctectomy) and
ileoanal anastomosis
POLYPOSIS SYNDROMES PEUTZ-JEGHERS’ SYNDROME What are the characteristics? P318
Hamartomas throughout the GI tract
jejunum/ileum > colon > stomach
POLYPOSIS SYNDROMES PEUTZ-JEGHERS’ SYNDROME What is the associated cancer risk from polyps? P318
Increased
POLYPOSIS SYNDROMES PEUTZ-JEGHERS’ SYNDROME What is the associated cancer risk for women with Peutz-Jeghers? P318
Ovarian cancer (granulosa cell tumor is most common)
POLYPOSIS SYNDROMES PEUTZ-JEGHERS’ SYNDROME What is the inheritance pattern? P318
Autosomal dominant
POLYPOSIS SYNDROMES
PEUTZ-JEGHERS’ SYNDROME
What are the other signs?
P318
Melanotic pigmentation (black/brown)
of buccal mucosa (mouth), lips, digits,
palms, feet (soles)
(Think: Peutz = Pigmented)
POLYPOSIS SYNDROMES
PEUTZ-JEGHERS’ SYNDROME
What is the treatment?
P318
Removal of polyps, if symptomatic (i.e., bleeding, intussusception, or obstruction) or large (>1.5 cm)
POLYPOSIS SYNDROMES
PEUTZ-JEGHERS’ SYNDROME
What are juvenile polyps?
P318
Benign hamartomas in the small bowel
and colon; not premalignant; also known
as “retention polyps”
POLYPOSIS SYNDROMES PEUTZ-JEGHERS’ SYNDROME What is Cronkhite-Canada syndrome? P319
Diffuse GI hamartoma polyps (i.e., no
cancer potential) associated with
malabsorption/weight loss, diarrhea, and
loss of electrolytes/protein; signs include
alopecia, nail atrophy, skin pigmentation
POLYPOSIS SYNDROMES
PEUTZ-JEGHERS’ SYNDROME
What is Turcot’s syndrome?
P319
Colon polyps with malignant CNS
tumors (glioblastoma multiforme)
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULOSIS
What is diverticulosis?
P319 (picture)
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
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULOSIS
Describe the pathophysiology
P319
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
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULOSIS
What is the incidence?
P319
≈50% to 60% in the United States by
age 60, with only 10% to 20% becoming
symptomatic
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULOSIS
What is the most common site?
P319
95% of people with diverticulosis have
sigmoid colon involvement
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULOSIS
Who is at risk?
P320
People with low-fiber diets, chronic
constipation, and a positive family
history; incidence increases with age
DIVERTICULAR DISEASE OF THE COLON DIVERTICULOSIS What are the symptoms/ complications? P320
Bleeding: may be massive
Diverticulitis, asymptomatic (80% of cases)
DIVERTICULAR DISEASE OF THE COLON DIVERTICULOSIS What is the diagnostic approach: Bleeding? P320
Without signs of inflammation: colonoscopy
DIVERTICULAR DISEASE OF THE COLON DIVERTICULOSIS What is the diagnostic approach: Pain and signs of inflammation? P320
Abdominal/pelvic CT scan
DIVERTICULAR DISEASE OF THE COLON DIVERTICULOSIS What is the treatment of diverticulosis? P320
High-fiber diet is recommended
DIVERTICULAR DISEASE OF THE COLON DIVERTICULOSIS What are the indications for operation with diverticulosis? P320
Complications of diverticulitis (e.g.,
fistula, obstruction, stricture); recurrent
episodes; hemorrhage; suspected carcinoma;
prolonged symptoms; abscess not
drainable by percutaneous approach
DIVERTICULAR DISEASE OF THE COLON DIVERTICULOSIS When is it safe to get a colonoscopy or barium enema/sigmoidoscopy? P320
Due to risk of perforation, this is
performed 6 weeks after inflammation
resolves to rule out colon cancer
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULITIS
What is it?
P320
Infection or perforation of a diverticulum
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What is the pathophysiology? P320
Obstruction of diverticulum by a
fecalith leading to inflammation and
microperforation
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULITIS
What are the signs/symptoms?
P320
LLQ pain (cramping or steady), change in bowel habits (diarrhea), fever, chills, anorexia, LLQ mass, nausea/vomiting, dysuria
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What are the associated lab findings? P320
Increased WBCs
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What are the associated radiographic findings? P320
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
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What are the associated barium enema findings? P321
Barium enema should be avoided in
acute cases
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS Is colonoscopy safe in an acute setting? P321
No, there is increased risk of perforation
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What are the possible complications? P321
Abscess, diffuse peritonitis, fistula,
obstruction, perforation, stricture
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What is the most common fistula with diverticulitis? P321
Colovesical fistula (to bladder)
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What is the best test for diverticulitis? P321
CT scan
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULITIS
What is the initial therapy?
P321
IV fluids, NPO, broad-spectrum
antibiotics with anaerobic coverage,
NG suction (as needed for emesis/ileus)
DIVERTICULAR DISEASE OF THE COLON
DIVERTICULITIS
When is surgery warranted?
P321
Obstruction, fistula, free perforation,
abscess not amenable to percutaneous
drainage, sepsis, deterioration with initial
conservative treatment
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What is the lifelong risk of recurrence after: First episode? P321
33%
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What is the lifelong risk of recurrence after: Second episode? P321
50%
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What are the indications for elective resection? P321
Two episodes of diverticulitis; should be
considered after the first episode in a
young, diabetic, or immunosuppressed
patient
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What surgery is usually performed ELECTIVELY for recurrent bouts? P321
One-stage operation: resection of involved
segment and primary anastomosis (with
preoperative bowel prep)
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What type of surgery is usually performed for an acute case of diverticulitis with a complication (e.g., perforation, obstruction)? P321
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)
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What is the treatment of diverticular abscess? P322
Percutaneous drainage; if abscess is not
amenable to percutaneous drainage, then
surgical approach for drainage is necessary
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS How common is massive lower GI bleeding with diverticulitis? P322
Very rare! Massive lower GI bleeding is
seen with diverticulosis, not diverticulitis
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What are the most common causes of massive lower GI bleeding in adults? P322
Diverticulosis (especially right sided),
vascular ectasia
DIVERTICULAR DISEASE OF THE COLON DIVERTICULITIS What must you rule out in any patient with diverticulitis/ diverticulosis? P322
Colon cancer
DIVERTICULAR DISEASE OF THE COLON
COLONIC VOLVULUS
What is it?
P322
Twisting of colon on itself about its
mesentery, resulting in obstruction and, if
complete, vascular compromise with
potential necrosis, perforation, or both
DIVERTICULAR DISEASE OF THE COLON COLONIC VOLVULUS What is the most common type of colonic volvulus? P322
Sigmoid volvulus (makes sense because the sigmoid is a redundant/“floppy” structure!)
DIVERTICULAR DISEASE OF THE COLON
SIGMOID VOLVULUS
What is it?
P322 (picture)
Volvulus or “twist” in the sigmoid colon
DIVERTICULAR DISEASE OF THE COLON
SIGMOID VOLVULUS
What is the incidence?
P323
≈75% of colonic volvulus cases (Think:
Sigmoid = Superior)
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What are the etiologic factors? P323
High-residue diet resulting in bulky stools 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
DIVERTICULAR DISEASE OF THE COLON
SIGMOID VOLVULUS
What are the signs/symptoms?
P323
Acute abdominal pain, progressive
abdominal distention, anorexia,
obstipation, cramps, nausea/vomiting
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What findings are evident on abdominal plain film? P323
Distended loop of sigmoid colon, often in
the classic “bent inner tube” or “omega”
sign with the loop aiming toward the RUQ
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What are the signs of necrotic bowel in colonic volvulus? P323
Free air, pneumatosis (air in bowel wall)
DIVERTICULAR DISEASE OF THE COLON
SIGMOID VOLVULUS
How is the diagnosis made?
P323
Sigmoidoscopy or radiographic exam with
gastrografin enema
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS Under what conditions is gastrografin enema useful? P323
If sigmoidoscopy and plain films fail to
confirm the diagnosis; “bird’s beak” is
pathognomonic seen on enema contrast
study as the contrast comes to a sharp end
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What are the signs of strangulation? P323
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, ↑ WBCs
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What is the initial treatment? P323
Nonoperative: If there is no strangulation, sigmoidoscopic reduction is successful in ≈85% of cases; enema study will occasionally reduce (5%)
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What is the percentage of recurrence after nonoperative reduction of a sigmoid volvulus? P323
≈40%!
DIVERTICULAR DISEASE OF THE COLON SIGMOID VOLVULUS What are the indications for surgery? P324
Emergently if strangulation is suspected 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%)
DIVERTICULAR DISEASE OF THE COLON
CECAL VOLVULUS
What is it?
P324
Twisting of the cecum upon itself and the
mesentery
DIVERTICULAR DISEASE OF THE COLON CECAL VOLVULUS What is a cecal “bascule” volvulus? P324
Instead of the more common axial
twist, the cecum folds upward (lies on the
ascending colon)
DIVERTICULAR DISEASE OF THE COLON
CECAL VOLVULUS
What is the incidence?
P324
≈25% of colonic volvulus (i.e., much less
common than sigmoid volvulus)
DIVERTICULAR DISEASE OF THE COLON
CECAL VOLVULUS
What is the etiology?
P324
Idiopathic, poor fixation of the right
colon, many patients have history of
abdominal surgery
DIVERTICULAR DISEASE OF THE COLON CECAL VOLVULUS What are the signs/ symptoms? P324
Acute onset of abdominal or colicky pain beginning in the RLQ and progressing to a constant pain, vomiting, obstipation, abdominal distention, and SBO; many patients will have had previous similar episodes
DIVERTICULAR DISEASE OF THE COLON
CECAL VOLVULUS
How is the diagnosis made?
P324
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)
DIVERTICULAR DISEASE OF THE COLON CECAL VOLVULUS What diagnostic studies should be performed? P324
Water-soluble contrast study (gastrografin),
if diagnosis cannot be made by AXR
DIVERTICULAR DISEASE OF THE COLON
CECAL VOLVULUS
What is the treatment?
P324
Emergent surgery, right colectomy with
primary anastomosis or ileostomy and
mucous fistula (primary anastomosis may
be performed in stable patients)
DIVERTICULAR DISEASE OF THE COLON CECAL VOLVULUS What are the major differences in the EMERGENT management of cecal volvulus versus sigmoid? P325
Patients with cecal volvulus require surgical reduction, whereas the vast majority of patients with sigmoid volvulus undergo initial endoscopic reduction of the twist