COLON

Question 1

Timing for surgery in FAP

Answer 1

wait until the patient has reached full physical maturity

safest surgical approach is total proctocolectomy with ileoanal anastomosis. Any residual rectal mucosa left behind is at risk of neoplasia.

Even with careful endoscopic surveillance of the rectal segment, invasive carcinomas can develop.

Question 2

management of Large sessile villous adenomas (>2 cm in diameter) found on endoscopy

Answer 2

great potential for malignant degeneration.

If such lesions cannot be completely removed by means of snare polypectomy, segmental surgical resection may be necessary.

Question 3

endoscopic management of Diminutive polyps (5 mm or less)

Answer 3

Diminutive polyps (5 mm or less) have little malignant potential.

If they are too small for snare polypectomy, ablation with a hot biopsy forceps is a reasonable approach.

Question 4

risk of synchronous adenoma

Answer 4

Because 30% to 50% of patients with one adenoma have synchronous adenoma elsewhere in the colon, the entire colon should be “cleared” by means of colonoscopy if a patient has a polyp.

Question 5

Nonspecific enteritis or pouchitis iof ileal pouch-anal anastomosis, presentation treatment

Answer 5

the most common late complication

occurring among as many as 15% of patients.

The clinical symptoms include high stool frequency, watery stools, fat malabsorption, urgency, nocturnal leakage, and rectal bleeding. Patients may have fever, malaise, and arthralgia.

he cause of this condition is unknown.

Most patients respond to treatment with metronidazole. this may be infused rectally

Question 6

Overall, surgical resection liver metastasis survival rate 5 years

Answer 6

associated with a 25% to 30% 5-year survival rate.

Question 7

Patients eligible for hepatic resection of metastatic disease

Answer 7

no evidence of extrahepatic tumor (LOOK UP LUNG)

fewer than four (LOOK UP IF MULT AND IN ONE LOBE)

lesions amenable to resection with negative surgical margins.

Question 8

This patient has a near totally resected sessile adenoma, what is management

Answer 8

If no malignancy is found in this patient, most authors would recommend follow-up in one to three years.

The National Polyp Study has demonstrated that surveillance colonoscopy can be safely deferred for three years after COMPLETE removal of all adenomas.

Because this patient had a large sessile polyp, follow-up sooner than three years is indicated.

Question 9

Sessile polyps greater than 2 to 3 cm are usually best approached how

Answer 9

surgically

because of the difficulty and increased risk of perforation with colonoscopic removal, and their increased likelihood of harboring a cancer.

Question 10

The Meissner plexus is located in the

Answer 10

submucosa between the muscularis mucosae and the circular muscle of the muscularis propria.

Question 11

the Auerbach plexus , is located

Answer 11

also know as the myenteric plexus,

between the inner circular muscle and outer longitudinal muscle layers of the colon.

Question 12

Dunphy sign refers to

Answer 12

acute appendicitis sign

increased pain with any coughing or movement and is related to inflammation that involves the parietal peritoneum.

Question 13

Rovsing sign is

Answer 13

acute appendicitis sign

right lower quadrant pain that is induced by palpation of the left lower quadrant and is highly suggestive of a right lower quadrant inflammatory process.

Question 14

The obturator sign is seen with

Answer 14

acute appendicitis sign

inflammation of a pelvic appendix

pain on INTERNAL rotation of the right hip.

Question 15

iliopsoas sign is

Answer 15

acute appendicitis sign

seen with a retrocecal appendix

pain on EXTENSION of the right hip.

Question 16

demonstrated to decrease time to resumption of bowel function described as flatus, bowel movement, or toleration of regular diet by 15-24 hours.

Answer 16

Alvimopan is an opioid antagonist that is peripherally acting and does not cross the blood brain barrier.

( CAREFUL-SESAP says no help and laparoscopic - and recommend gum chewing)

approved by the FDA for perioperative use after partial large or small bowel resections with primary anastomosis.

Question 17

Most of the water and electrolytes from the chyme is absorbed where

Answer 17

MOST small boweL

SECOND most PROXIMAL colon also absorbs water and ions but almost no nutrients (99,121,122).

Question 18

Vascular ectasia occurs most frequently in the

Answer 18

CECUM and ascending colon,

other sites include: transverse and left colon or rectum in as many as 20% to 30% of cases

Question 19

At endoscopic examination, Vascular ectasia findings and presentation

Answer 19

flat or slightly raised, red, and 2 to 10 mm in diameter.

dilated, thin-walled vessels that appear to be ectatic veins, venules, and capillaries localized to the submucosa and mucosa.

Advanced lesions - arteriovenous communications, manifest as massive hemorrhage and hematochezia.

More than 90% of patients stop bleeding spontaneously,

Approximately 50% of patients with vascular ectasia have cardiac disease, most commonly atherosclerotic coronary disease.

25% of patients have aortic stenosis ( careful, aortic ectasias dilation and thinning)

Question 20

The mucosal surface of the colon consists of

Answer 20

columnar epithelium made up of regularly arranged crypts and numerous goblet cells.

Unlike that of the small intestine, the columnar epithelium of the colon does not possess villi.

Question 21

The muscularis propria of the colon consists of

Answer 21

an inner circular layer

AND outer longitudinal layer.

The thick circular muscle forms a continuous layer around the entire circumference of the colon.

Question 22

appendix carcinoid tumors risk of nodal metastases with small bowel carcinoid

Answer 22

Small bowel carcinoids have a greater metastatic potential at a smaller size.

Nodal and/or liver metastases are present at initial presentation in 20% to 30% of small bowel carcinoids 1 cm or smaller.

carcinoid metastases and carcinoid syndrome or less common from hind gut lession

Question 23

Lynch syndrome

Answer 23

autosomal dominant

combination of cancer in the colon,
female genital tract (ovaries, endometrium, and uterus),

Question 24

Amsterdam criteria

Answer 24

the Amsterdam criteria
used for Lynch syndrome = HNPCC

3,2,1
relatives
generations
age less than 50

3 relatives with colorectal cancer (one is a first-degree relative of the other two);

≥2 generations are involved,

≥1 case appears before 50 years of age)

Question 25

ocular manifestations of ulcerative colitis

Answer 25

iritis, 
uveitis, 
conjunctivitis, 
episcleritis, 
retinitis, 
retrobulbar neuritis. 

ocular symptoms are closely related to disease activity and respond to therapy with steroids or immunosuppressive agents

EXCEPT ulcerative panophthalmitis

Question 26

Overall mean 24-hour stool frequency bowel movements after ileal pouch-anal anastomosis after year

Answer 26

five to six

Question 27

interventions that have never been shown in large scale studies to decrease the risk of postoperative ileus.

Answer 27

Administration of metoclopramide

Early postoperative feeding

Question 28

Vascular ectasia can be diagnosed with and compare sensitivities

Answer 28

colonoscopy or selective mesenteric angiography.

Colonoscopy has been reported to have a sensitivity of 80% in the detection of vascular ectasia.

Question 29

treatment of bowel vascular ectasia

Answer 29

bleeding from colonic (MOST common) vascular ectasia

treated by endoscopic modalities with a procedure-related morbidity of 2% to 10%.

Patients bleeding from vascular ectasia for whom endoscopic hemostatic modalities are unsuccessful or unavailable can be treated with resection of the colon after preoperative localization of the bleeding site.

For the usual patient, right colectomy with ileotransverse colostomy is the best treatment. or

Question 30

defined taeniae

Answer 30

The outer longitudinal muscle layer is grouped into three bands known as taeniae.

These bands are positioned approximately 120 degrees apart around the circumference of the colon

one taenia along the mesenteric border and the other two on the antimesenteric border of the colon.

Question 31

haustra coli.

Answer 31

The sacculations seen between the taeniae (taeniae are 3 bands of outer longitudinal muscle)

Question 32

The transverse colon is suspended by what and compare relative mobility

Answer 32

the transverse mesocolon

considered completely intraperitoneal.

most mobile portion of the colon and can be present anywhere from the upper abdomen down into the pelvis.

Question 33

described the course of the greater omentum and its attachments

Answer 33

The greater omentum descends from the greater curvature of the stomach in front of the transverse colon and ascends to attach to the transverse colon on its anterosuperior edge.

Question 34

Lynch syndrome colon cancer process

Answer 34

HNPCC

Colonic adenomas can occur by the third and fourth decades,

cancer appearing by the fifth decade (mean 40-45 years of age).

Patients do not develop a “carpet” of polyps as they do in polyposis syndromes.

DNA mismatch repair defect.

Question 35

Cowden’s syndrome

Answer 35

autosomal dominant juvenile polyposis syndrome (average age at diagnosis is 18 years)

characterized by colonic hamartomous polyposis and is

associated with breast and thyroid cancer.

Their risk for colorectal and other GI cancers is 15% by age 35 and 65% by age 65).

Question 36

Familial polyposis coli

Answer 36

(familial adenomatous polyposis - FAP

numerous colonic polyps and development of cancer by age 40;

NOT associated with uterine cancer (as is seen in lynch)

Question 37

Turcot syndrome

Answer 37

colonic polyposis syndrome

associated with brain tumors.

Question 38

colon phys

Answer 38

Approximately 1,500 mL of ileal effluent reaches the cecum over a 24-hour period, of which 90% is water. Of this amount, only 100 to 150 mL of water appears in the stool. The colon has a tremendous reserve capacity that allows it to absorb as much as 5 to 6 L of water over a 24-hour period. Water absorption in the colon is a passive process that depends primarily on the osmotic gradient established by the active transport of sodium across the colonic epithelium. Salt and water absorption is greater in the right colon than in the left colon and sigmoid colon. Patients undergoing a right hemicolectomy should be counseled preoperatively that they might experience loose bowel movements or frank diarrhea in the early postoperative period. Sodium absorption involves the passive movement of sodium across the apical membrane into the mucosal cell down an electrochemical gradient. To maintain an adequate electrochemical gradient, intracellular sodium is removed from the cell into the interstitial space in exchange for potassium. This process is energy dependent and controlled by a Na+-K+-ATPase pump at the basolateral membrane of the colonic epithelium. Short-chain fatty acids, which include acetate, butyrate, and propionate, are absorbed in a concentration-dependent manner. They are an important energy substrate for the colonic epithelial cells and are the major fecal anions.

Question 39

superior mesenteric artery arises from the

Answer 39

suprarenal aorta,
runs posteriorly to the pancreas,
passes anteriorly to the third portion of the duodenum.

Question 40

The superior mesenteric artery gives rise to

that supply the

Answer 40

the ileocolic and middle colic branches that supply the cecum, ascending colon, and proximal transverse colon.

Question 41

The right colic artery,

Answer 41

which also supplies the ascending colon, can originate as a branch of the ileocolic artery or it can arise directly from the superior mesenteric artery.

Question 42

The inferior mesenteric artery arises from the

Answer 42

infrarenal aorta and supplies the distal transverse colon, descending colon, sigmoid colon, and upper rectum through its left colic, sigmoidal, and superior hemorrhoidal branches.

The middle and inferior hemorrhoidal arteries arise from the hypogastric arteries and supply the distal two thirds of the rectum. A series of arterial arcades along the mesenteric border of the entire colon, known as the marginal artery of Drummond, connect the superior mesenteric and inferior mesenteric arterial systems. The veins that drain the large intestine bear the same terminology and follow a similar course to the corresponding arteries. The veins from the right colon and transverse colon, along with the veins draining the small intestine, drain into the superior mesenteric vein. The superior mesenteric vein runs slightly anterior and to the right of the superior mesenteric artery. The superior mesenteric vein courses beneath the neck of the pancreas, where it joins the splenic vein to form the portal vein. The inferior mesenteric vein drains blood from the left colon, sigmoid colon, rectum, and superior anal canal. The inferior mesenteric vein ascends over the psoas muscle in a retroperitoneal plane. The vein courses under the body of the pancreas to drain into the splenic vein. The superior hemorrhoidal veins drain blood from the rectum into the portal system through the inferior mesenteric vein. The middle and inferior hemorrhoidal veins drain blood from the lower rectum and anal canal into the systemic venous circulation through the internal iliac veins.

Question 43

sigmoid volvulus The most common symptom

Answer 43

pain,

The pain is in the lower midabdomen and is consistent with the origin of pain afferents in the hindgut.

Question 44

sigmoid volvulus most common sign

Answer 44

distention from accumulation of colonic gas.

Question 45

Colorectal carcinoma in Crohn’s disease occurs predominantly among what gender, age, prognosis, location

Answer 45

men with a mean age in the early fifties.

One recent study reported the cumulative frequency was 8% for ulcerative colitis and 7% for Crohn’s colitis at 20 years.

Most carcinomas are located in the left colon;

75% are distal to the splenic flexure.

Controlled for stage of disease, colorectal carcinoma associated with either ulcerative colitis and Crohn’s disease or spontaneous colorectal carcinoma all have a similar prognosis.

Question 46

The most common complication following operation of restorative proctocolectomy is

Answer 46

small-bowel obstruction.

The rate of bowel obstruction necessitating reoperation has been reported to be 10% to 20% in most series of patients undergoing ileal pouch-anal anastomosis.

Pelvic and wound infections have been reported to occur among 10% of patients undergoing ileoanal anastomosis, although the overall infection rate has been approximately 5% in several series.

Conversion to permanent ileostomy because of postoperative complications is necessary for fewer than 5% of patients.

Question 47

Initial management of toxic megacolon includes

Answer 47

intravenous fluid and electrolyte resuscitation, nasogastric suctioning, administration of broad-spectrum antibiotics, and total parenteral nutrition (if they dont have peritoneal signs - even though the look sick with WBC of 19)..

In the presence of toxic megacolon or colonic perforation, the operation should be definitive without being overly aggressive.

Abdominal colectomy with ileostomy and Hartmann closure of the rectum is the best procedure.

After recovery, a delayed operation for restoration of continence can be performed. Leaving the rectum intact allows it to be used for subsequent mucosal proctectomy and ileoanal anastomosis.

Question 48

The external anal sphincter

Answer 48

composed of voluntary striated muscle.

direct control of the CNS via the inferior branch of the internal pudendal nerve and the perineal branch of the fourth sacral nerve.

Question 49

The internal anal sphincter

Answer 49

a specialized continuation of the circular muscle of the rectum,

innervated by the autonomic nervous system (not the same as the central nervous system).

It is an involuntary muscle normally contracted at rest.

sympathetic innervation from the hypogastric nerves (L5)

parasympathetic innervation from pelvic splanchnic nerves (S2-S4)

Question 50

Distal esophageal longitudinal muscle, small bowel longitudinal muscle and small bowel circular muscle are innervated by neural fibers from the

Answer 50

myenteric (Auerbach) plexus found within the muscularis propria. This creates an intrinsic autonomic nervous system.

NOT considered central nervous system

Question 51

acute appendicitis describe a characteristic set of symptoms and their timing

Answer 51

The initial symptom is the periumbilical pain that is visceral in nature.

followed by nausea and/or vomiting, although some patients will only experience anorexia.

pain then shifts to the right lower quadrant as the inflammatory process involves the overlying parietal peritoneum.

At this point, the patient may describe pain in the right lower quadrant that is exacerbated by various movements.

Physical examination reveals tenderness in the right lower quadrant with signs of peritoneal irritation.

Fever then ensues, and is usually of a low-grade nature, especially early on in the course.

Eventually, laboratory tests reveal a leukocytosis, usually mild in nature.

In those patients where the symptoms do not follow this temporal pattern, one must be suspicious of a diagnosis other than acute appendicitis.

Question 52

familial adenomatous polyposis

Answer 52

adenomatosis polyposis coli gene.

Question 53

colorectal tumorigenesis is the p53 gene - how common

Answer 53

Alteration in p53 is one of the most common genetic events in malignant disease among humans.

p53 has been found in more than 75% of persons with colorectal carcinoma.

GF 2011

Question 54

deleted in colorectal carcinoma” gene, also called DCC, how common

Answer 54

Mutations in DCC are present in 47% of persons with late adenoma and 73% of those with carcinoma.

The DCC protein shares homology with the neural cell adhesion molecule family that regulates cell adhesion and recognition.

Question 55

Most conssistent dietry influence on colorectal cancer

Answer 55

Fat intake has had the most consistently positive association

• the proposed mechanism by which dietary fat increases the risk of colonic cancer is interaction with bile acids.

fiber intake the most consistently inverse association with incidence of colorectal cancer.

Question 56

updated guidelines for screening average-risk individuals for colorectal cancer - All guidelines recommend

Answer 56

All guidelines recommend :

annual fecal occult blood testing (FOBT) with a high-sensitivity test,

flexible sigmoidoscopy every 5 years,

or

colonoscopy every 10 years as options.

Other options included in some, but not all, guidelines include combined sigmoidoscopy and FOBT, double-contrast barium enema every 5 years, computed tomography colonography every 5 years, and stool DNA testing (interval uncertain).

American Cancer Society, the U.S. Multi-Society Taskforce on Colorectal Cancer, and the American College of Radiology.

Revised guidelines have also been issued by the U.S. Preventive Services Taskforce, the American College of Gastroenterology, and the National Comprehensive Cancer Network.

While these guidelines may differ slightly from each other, all stress the importance of cancer prevention.

GF 2011

Question 57

Opinion and practice about the ideal management of cases of well-localized diverticulitis

Answer 57

without systemic signs of sepsis continue to evolve. Free perforation with evidence of peritonitis requires emergency operation and is the one, generally agreed on, contraindication for primary anastomosis. Resection of the involved segment of colon is always preferred to simple proximal diversion unless removing the affected segment is technically a high-risk procedure

Question 58

Most propulsion in the colon occurs as a result of:

Answer 58

Giant migrating motor contractions -

for the giant bowel

most notable in the transverse colon or descending colon. They only occur approximately three times a day, and each contraction moves the luminal contents approximately one third of the length of the colon

Question 59

periappendiceal abscess/phlegmon.

Answer 59

best treated initially with nonoperative therapy, including intravenous hydration and antibiotics. A CT scan may be performed, and if a large collection/abscess is identified, then a CT-guided catheter can be placed. In many patients, antibiotics alone will be sufficient.

Urgent operation in these patients is associated with increased morbidity, including the possible injury of surrounding structures such as the small intestine, and the possible need for an ileocecectomy or cecostomy tube placement.

Initial nonoperative management is therefore recommended, and an interval appendectomy can be performed once the inflammatory process has completely resolved, usually approximately 10 to 12 weeks following the initial presentation.

Whether or not an interval appendectomy is required remains a controversial issue, since the incidence of recurrent appendicitis is probably quite low (approximately 10%).

Question 60

protooncogene In colon cancer

Answer 60

Approximately 50% of cases of colorectal carcinoma and a similar percentage of cases of adenoma larger than 1 cm in diameter have been found to have the ras gene mutations.

In contrast, fewer than 10% of patients with adenoma smaller than 1 cm have this mutation. It has been postulated that the ras gene mutation may be the initiating event in some types of colorectal carcinoma or may promote clonal expansion of a mutated cell population.

It appears that the ras gene mutation alone is not responsible for tumorigenesis. Additional molecular events appear to be necessary.

Question 61

Acute appendicitis typically begins with what findings and what are innervation pathways

Answer 61

poorly localized central abdominal pain associated with anorexia and nausea - visceral origin.

As the inflammatory process becomes transmural, a transition to somatic-type pain develops.

This pain is associated with rigidity and tenderness of overlying muscle groups and organs in direct continuity with the inflammatory process.

Question 62

epinyms for signs of acute appy

Answer 62

typical cases of appendicitis, display tenderness over McBurney point

and often an associated psoas sign (pain on thigh extension).

IF appendix is deep within the pelvis, obturator internus muscle may be associated with a positive obturator test (suprapubic pain on internal and external rotation of the thigh). BOTH directions

Tenderness on rectal examination may be present.

Additionally, a periappendiceal inflammatory process and abscess in continuity with the right adnexa may be associated with cervical motion tenderness.