ANORECTAL

Question 1

workup of anal incontinence?

Answer 1

Ultrasonographic examination of

accurately localize defects and asymmetry.

reliable for mapping defects of the external sphincter and is more comfortable for patients than is electromyographic mapping.

Question 2

Gracilis muscle transposition, for anal incontinence?

Answer 2

has fallen out of favor because of an unsatisfactory

short-term success rate of approximately 50%.

This striate muscle is capable of producing voluntary contraction to occlude the anal canal. It is, however, unable to preserve a closed lumen at all times because of lack of an inherent tone within the muscles, unlike the resting anal tone generated by the internal sphincter muscle.

Question 3

Use of an electrostimulating device for anal incontinence

Answer 3

short-term success rate of 75%.

Long-term, low-frequency electrical stimulation of skeletal muscle converts fast-twitch muscle into slow-twitch muscle capable of sustained activity.

This operation is expensive and is experimental.

Question 4

artificial anal sphincter

Answer 4

inflatable cuff of silicone rubber placed around the upper anal canal.

The pressure-regulating balloon is placed to the left or right of the bladder, and the pump with which the patient can inflate and deflate the cuff is placed in the labia majora or in the scrotum.

This operation has been received with enthusiasm in Europe but is not approved for clinical application by the U.S. Food and Drug Administration.

Question 5

result with chemotherapy and radiation therapy and rectal cancer in terms of local recurrence and survival

Answer 5

Postoperative combination therapy improved BOTH local control and survival in two randomized trials.

A National Cancer Institute Consensus Conference in 1990 recommended that patients with:

T3 (this STAGE II) and/or N1 to N3 tumors should receive fluorouracil-based chemotherapy plus concurrent pelvic irradiation.

NEOadjuvant has been shown to decrease local recurrence but not definitive improve on survival

NEOadjuvant radiation stumor shrinkage and downstaging to allow sphincter preservation with excellent functional results.

to

Question 6

associated symptoms with rectal radiation therapy

Answer 6

Diarrhea preoperative radiation therapy in fewer than 50% of patients in most series.

Uncontrolled nausea and vomiting occur in only 5%.

Question 7

physiology of to external beam radiation therapy works on rectal cancer

Answer 7

cytotoxic effect

damaging the helical configuration of the nucleic acids’ DNA,

thereby interfering with the ability of cancer cells to reproduce.

Question 8

intersphincteric fistula

Answer 8

intersphincteric plane.

external opening usually is in the perianal skin close to the anal verge.

Question 9

transsphincteric fistula

Answer 9

starts in the intersphincteric plane

or

deep postanal space.

track traverses external sphincter,

external opening is at the ischioanal fossa.

Horseshoe fistulas are in this category.

Question 10

Horseshoe fistulas

Answer 10

type of trans-sphincteric fistula that starts in deep post anal space or intersphincteric plane and exits at ischioanal fossa.

Question 11

Suprasphincteric fistulas

Answer 11

start in the intersphincteric plane

in the mid-anal canal

pass upward to a point above the puborectalis muscle.

fistula passes laterally over this muscle and downward between the puborectalis and levator ani muscles into the ischioanal fossa.

Question 12

extrasphincteric fistula

Answer 12

passes from perineal skin

through the ischioanal fossa and the levator ani muscle

penetrates the rectal wall.

Question 13

Extrasphincteric fistulas can arise from what causes

Answer 13

cryptoglandular origin, trauma, foreign body, or pelvic abscess.

Question 14

Chronic anal fissure usually is deep, exposing the what is operative treatment at a rate of potential complication

Answer 14

internal anal sphincter.

Lateral internal sphincterotomy is effective but has been associated with decreased continence in up to 7% of patients.

Question 15

Biopsy of a lesion in the anus revealed an invasive apocrine gland neoplasm. The deep margins include striated muscle infiltrated by neoplastic cells. what is the diagnosis

Answer 15

perianal Paget disease

Question 16

Biopsy of a lesion in the anus revealed an invasive apocrine gland neoplasm. The deep margins include striated muscle infiltrated by neoplastic cells. what is the treatment

Answer 16

Wide local excision is the best treatment in the absence of invasive carcinoma.

multiple punch biopsies may be needed to determine the extent of involvement.

For more advanced lesions with underlying carcinoma: abdominoperineal resection is indicated.

Inguinal lymph node dissection is performed only if groin lymph nodes are clinically positive for metastasis.

Question 17

perianal Paget disease metastasis where

Answer 17

sites of metastasis, in order of frequency:

inguinal and pelvic lymph nodes,

liver, 
bone, 
lung, 
brain, 
bladder, 
prostate, 
adrenal gland.

Question 18

At colonoscopy for rectal bleeding, a 45-year-old man has a 1.0-cm submucosal lesion of the rectum. The biopsy diagnosis is granular cell myoblastoma. weighted diagnosis and treatment

Answer 18

tumor most likely arises from the neural crest, with the Schwann cell the current popular favorite as the cell of origin.

” schwannoma of the rectum”

Wide local excision generally provides adequate therapy. Thus, for colorectal lesions, colonoscopic excision is the procedure of choice.

The submucosal location of most of these tumors makes this a suitable route.

Transabdominal resection, either laparoscopically or via open celiotomy, is reserved for tumors that cannot be successfully removed endoscopically.

recurrence is unusual even after demonstration of positive margins of resection, in this instance observation is the appropriate choice for follow-up.

Rigorous and protracted follow-up is appropriate.

Question 19

Fistula-in-ano anatomy and treatment

Answer 19

is a chronic form of perianal abscess that is spontaneously or surgically drained but in which the abscess cavity does not heal completely.

inflammatory track with a primary opening (internal opening) in the anal crypt at the dentate line and a secondary opening (external opening) in the perianal skin.

unroofing the fistula, eliminating the primary opening (infective source), and establishing adequate drainage. Failure to open the entire track can lead to recurrence.

Fistulectomy, excision of the fistula track, has no advantages over fistulotomy and is more likely to cause anal incontinence.

(CAREFUL-SESAP - not using setons)
A seton should be applied. A seton is a suture, usually silk, rubber band, or strip of Penrose drain, drawn through a fistula. It is used to tie the muscles covering the fistula to cause fibrosis or to cut the muscles. In the second stage (average interval, 6 to 8 weeks), fistulotomy is performed. Incontinence after proper use of a seton is uncommon, even when the fistula is deep.

Question 20

Squamous cell carcinoma of the anal canal treatment

Answer 20

Nigro’s combination of radiation and chemotherapy eliminated the primary lesion in most patients.

IF persistent small foci of disease, some authors attempt local excision as the next line of therapy, whereas others advocate abdominoperineal resection or additional courses of chemoradiation therapy.

Question 21

melanoma of the anal canal how common is it and what is treatment

Answer 21

melanoma anal canal is the third most common site of involvement!

exceeded only by skin and the eyes.

Anal canal melanomas should be treated by abdominoperineal resection. Although radical extirpation does not result in satisfactory long-term survival results, abdominoperineal resection is still recommended because the only five-year survival rates come from this approach.

Question 22

treatment of choice for adenocarcinoma of the lower third of the rectum.

Answer 22

Abdominoperineal resection

CAREFUL- individualized on sphincter involvement.

Question 23

Described the progression that causes rectal prolapse

Answer 23

considered a form of intussusception.

usually starts in the anterior aspect of the lower rectum, approximately 8 cm from the anal verge.

By the time rectal prolapse is diagnosed, 50% of patients already have anal incontinence.

Incontinence in rectal prolapse is caused by damage to the pudendal nerve, which supplies the sphincter muscles, from prolonged stretching.

Question 24

with percent of rectal prolapse patient’s regain continence after surgery

Answer 24

ONLY 50% of patients with fecal incontinence from rectal prolapse improve after repair of the prolapse.

Because the return of incontinence takes as long as 6 to 12 months, operative management of incontinence should be postponed for 1 year.

Question 25

Perineal rectosigmoidectomy

Answer 25

has appeal as a lesser procedure, particularly for elderly patients or patients in a high surgical risk category.

young male patient may also prefer this because of the decreased risk of sexual dysfunction

The short-term recurrence rate is approximately 10%.

Question 26

Abdominal rectopexy with or without resection

Answer 26

major operation with high risk of morbidity and mortality, but it has a low recurrence rate.

Patients should be cautioned that despite successful transabdominal repair, approximately 50% of the patients continue to have defecation problems.

Question 27

Most carcinoids in the gastrointestinal tract occur where

Answer 27

ileum and the appendix.

The rectum is the next most common site,

occasional carcinoid tumors occur in the colon.

Question 28

extremely important prognostic factor carcinoids

Answer 28

Tumor size

Question 29

treatment of rectal carcinoid

Answer 29

Transanal local excision suffices for definitive therapy because small tumors rarely metastasize of the rectum Approximately 60% of rectal carcinoids manifest as asymptomatic submucosal nodules less than 2 cm in diameter.

Malignant potential is seen almost exclusively among patients with tumors larger than 2 cm.

More radical excision of larger rectal lesions may be needed for local control; however, the results of radical excision of large rectal carcinoids are poor because the lesions are likely to metastasize.

Question 30

Endorectal ultrasound examination (EUS

Answer 30

mainstay for preoperative evaluation of rectal cancers.

Wall invasion can be assessed with a specificity greater than 90% and a sensitivity of over 95%.

It is more accurate in predicting wall invasion than computed tomographic (CT) scan (91% versus 75%), and comparable to magnetic resonance imaging (MRI) with an endorectal coil (both above 90%).

can accurately predict perirectal lymph node involvement

Because of peritumor inflammation, EUS is more likely to overstage than understage a tumor.

EUS is very good for determining whether the tumor is confined to the muscularis, but not in differentiating T1 from T2 lesions. When used to assess the effectiveness of preoperative radiation therapy, it can ascertain shrinkage, but is not accurate in predicting pathologic stage.

Question 31

Radiation therapy is recommended for patients with rectal cancer when

Answer 31

stage II or III rectal cancers.

In a randomized, prospective study, 204 patients with stage II or III rectal cancer were randomized to receive postoperative radiation alone or radiation therapy plus 5-fluorouracil and semustine chemotherapy. The group who received chemotherapy had improved local tumor control and a higher overall survival rate. In another prospective study, semustine was found not to be an essential component of effective adjuvant therapy. Based on these results and those of other clinical studies, the National Institutes of Health has recommended that patients with stage II or III rectal cancer receive postoperative chemotherapy and radiation therapy as standard care.

Question 32

adjuvant therapy for melanoma of the anal canal

Answer 32

Melanoma of the anal canal is radioresistant and does not respond to chemotherapy or immunotherapy.

Question 33

where is melanoma seen to aggressively spread with anal canal presentation

Answer 33

marked tendency to spread submucosally into the rectum

rarely invades adjacent organs,

Lymphatic spread to the mesenteric nodes has occurred among approximately one third of the patients by the time of diagnosis.

Spread to the inguinal nodes occurs LESS often.

Hematogenous spread to the liver and lung is early and rapid, accounting for most deaths!! CAREFUL this is in distinction to cutaneous melanoma

Question 34

management of anal canal melanoma

Answer 34

There is no statistical difference in survival rates when patients treated by means of abdominoperineal resection are compared with those treated by means of local excision.

Both 5-year survival rates are approximately 15% to 17%. It appears that local control of the disease after the operation is not as much a problem as distant metastasis, which is the main cause of death. For small lesions, wide local excision is the best procedure.

for example 1.5 cm and 2 cm above the dentate line - wide local excision only

Question 35

Per the AJCC guidelines as this patient has 4 or more positive lymph nodes he has what stage rectal cancer

Answer 35

N2 disease which makes him stage IIIC.

Question 36

radiation field recommended for rectal cancer

Answer 36

just pelvic radiation

CAREFUL - previous question “pelvic radiation therapy has become standard treatment. Elective radiation to clinically normal inguinal nodes reduces the risk of lymph node failure and carries little morbidity. “

Question 37

. HPV types 6 and 11 are associated with

Answer 37

lesions such as warts and anal intraepithelial neoplasia or low-grade dysplasia that rarely progresses to invasive carcinoma. In contrast, HPV types 16, 18, 31, 33, 34, and 35 are most commonly associated with high-grade dysplasia, anal intraepithelial neoplasia, and carcinoma of the anus and cervix. HPV types 6 and 11 are maintained as extrachromosomal episomes, whereas HPV types 16 and 18 are integrated into host DNA, which explains the differing propensities to initiate development of carcinoma. Immunosuppressed patients, such as recipients of renal transplants or cardiac allografts and patients who have recently completed chemotherapy, are at increased risk of anal carcinoma. Approximately 50% of patients with human immunodeficiency virus (HIV) infection have detectable HPV DNA.

Question 38

Treatment for of squamus anal canal cancer is

Answer 38

all stages!

chemoradiation. The modified Nigro regimen is currently used and consists of 5-fluorouracil, mitomycin C, and pelvic radiation therapy with 50 Gy to the primary carcinoma and 35-45 Gy to pelvic inguinal lymph nodes. Late adverse effects associated with radiation of the anal region include proctitis, diarrhea, incontinence, anal ulcers, and stenosis, with need for permanent colostomy in ~10% of patients. Abdominoperineal resection (APR) has a role for persistent or recurrent anal canal cancer. Studies of salvage APR show better survival in recurrent disease. Perineal wound problems are common from APR as surgery takes place in an irradiated field. Patients who undergo chemoradiation for anal cancer have a higher perineal wound complication rate following APR than do those undergoing chemoradiation for rectal cancer and primary reconstruction with a rectus abdominis myocutaneous flap or other advancement flap should be considered.

Question 39

Hemorrhoidectomy should be considered when

Answer 39

the hemorrhoids are severely prolapsed through the anus, necessitating manual replacement, or are complicated by associated pathologic conditions, such as ulceration, fissure, fistula, large hypertrophied anal papilla, or extensive skin tags. An elliptical excision starts at the perianal skin, includes external and internal hemorrhoids, and ends at the anorectal ring. The mucosa and submucosa are dissected from the underlying internal sphincter muscle. Unless there is an associated anal stenosis or chronic anal fissure, internal sphincterotomy is not performed. The entire wound is closed with running absorbable suture. The largest and the most redundant hemorrhoid should be excised first. No packing is placed in the anal canal. Urinary retention is the most common complication of hemorrhoidectomy. It can be avoided if intravenous fluids are restricted during the procedure and the anterior perineum is not injected with excessive local anesthetic.

Question 40

In selected cases of pedunculated polyps, conservative management without colectomy can be undertaken if

Answer 40

does not contain poorly differentiated tumor cells

NO vascular invasion

negative resection margin has been obtained at the level of the stalk.

does not penetrate the muscularis mucosae

(CAREFUL - this is not submucosa that can still just be taken with scope) - ie, still in situ malignant tumor if does not go into muscularis mucasae and still taken with scope

Question 41

Operation should be done in what time frame of neoadjuvant chemotherapy and radiation therapy for rectal cancer.

Answer 41

one to six weeks after cessation of Neoadjuvant

Question 42

Lesions will be downstaged in what percent in rectal cancer with neoadjuvant

Answer 42

Lesions will be downstaged in 50 per cent to 75 per cent of patients and neoadjuvant

Question 43

Astler-Coller system.

Answer 43

= Dukes stage

One of the more commonly used staging systems is the modified Astler-Coller system. According to this system, stage A represents tumors that invade into the mucosa only. Stage B1 tumors invade into but not through the muscularis propria. Stage B2 lesions invade through the bowel wall without adjacent organ involvement, whereas stage B3 tumors involve adjacent organs. Stage C tumors involve regional lymph nodes and are subgrouped into stages C1, C2, and C3, according to depth of bowel-wall penetration. Stage D represents evidence of distant organ involvement. In general, the 5-year survival rate among patients with stage D disease is less than 10%. Overall, the 5-year survival rates for stages A, B, and C are 90%, 77%, and 47%, respectively. Additional studies have revealed that among patients with Dukes stage C disease, the number of positive nodes is an important predictor of survival.

Question 44

A 19-year-old man has bloody diarrhea (10 bowel movements per day) and weight loss (10 pounds [4.5 kg]). Physical examination reveals two circular, 4-cm erythematous lesions on the trunk. Each lesion has an area of necrosis in the center. The abdominal examination reveals mild hypogastric tenderness. The stool is guaiac positive. The most appropriate next diagnostic step is which of the following? and what is the dx

Answer 44

The diagnosis of ulcerative colitis is one of exclusion. There are no definitive laboratory, radiologic, or histologic features. All patients with bloody diarrhea should have an infectious cause excluded. Stool samples and biopsy specimens should be evaluated for Campylobacter, Salmonella, pathogenic Escherichia coli, and Clostridium difficile organisms and amebic colitis. Flexible sigmoidoscopy is the first step in diagnosis, because ulcerative colitis involves the distal colon and rectum in 90% to 95% of cases. Mild cases may show only a loss of normal vascular pattern, a granular texture, and microhemorrhages when the friable mucosa is touched with the endoscope. Advanced cases are characterized by spontaneous bleeding, ulceration, and purulent exudate. Mucosal biopsy is essential in establishing the diagnosis. Lesions of the skin and oral cavity are frequently found among patients with ulcerative colitis. Pyoderma gangrenosum occurs among approximately 1% of patients.