Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Surgery > Colon, Rectum, Anal Canal > Flashcards

Colon, Rectum, Anal Canal Flashcards

1
Q

Diverticulitis pathophys

A
  • Diverticulosis = mucosal herniations protruding through intestinal layers and smooth muscle along with natural weakness in muscularis mucosa created by nutrient vessels in wall of the colon. These pouches are lined by mucosa and serosa only
  • The condition appears to be associated with low fiber diet, constipation, and obesity
  • Diverticula can appear anywhere along GI tract, but mostly in colon and most commonly in sigmoid colon where intraluminal pressures are highest
  • Diverticulitis is inflammation of the diverticula. Obstruction of neck of diverticula can result in stasis of intralminal fecal material causing bacterial overgrowth and infection. This can cause:
    1) Micro/macro perf (may be walled off by pericoloc fat/mesentery)
    2) Abscess (and possible rupture leading to peritonitis)
    3) Fistula to adjacent organs or skin (most common in men is colovesicular)
    4) Recurrent attacks can yeild scar tissue and narrowing/obstructing of colon
  • Abscess can be peritoneal or retroperitoneal depending on segment of colon (posterior ascending and descending colon are retroperitoneal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Prevalence of diverticulitis

A

Diverticulosis: 5% before age 40
65% before age 85. Usually asymptomatic

15-25% of those with diverticulosis get diverticulitis
- Of these, 75% have just colicky pain and 25% require surgery

20% of patients with diverticulitis are younger than 50

Anatomic prevalence:

  • 70% L side of colon
  • 75% R sided in Asians
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Diverticulitis morbidity/mortality

A

20-35% with conservatively managed diverticulitis experience recurrence

More severe illness in younger patients, immunocompromised, significant comorbid conditions, and those taking anti-inflammatory meds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Typical history of diverticulitis

A

1 symptom = LLQ pain

  • can mimic many abdominal conditions due to location variability of the diverticula
  • Mild disease = localized abdominal pain, colicky pain, change in bowel habits (usually constipation more than diarrhea)
  • After perf = fever, anorexia, nausea,vomiting
  • If colovesicular fistula = dysuria (90%), pneumaturia (70%), fecaluria (70%)
  • Bleeding more common in simple diverticulosis NOT diverticulitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Workup for diverticulitis

A

H&P usually enough

Look for leukocytosis with L shift

If ambiguous, do CT

  • Pericolic fat stranding (98%)
  • Colonic diverticula (84%) - note this is NOT 100%
  • Bowel wall thickening (70%)
  • Phlegmon or abscess (35%)

Colonoscopy and contrast enema are contraindicated with possible perforation***

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Hinchey classification of acute diverticulitis

A

Stage 1 = Pericolic abscess

Stage 2 = Distant or remote abscess

Stage 3 = Prurulent peritonitis

Stage 4 = Fecal peritonitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Tx for diverticulitis

A

Medical Care

  • Liquid diet and 7-10d of oral broad-spectrum antibiotics (cipro/metronidazole)
  • Long term care = high fiber and low fat diet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Indications for surgery in diverticulitis

A

1) Free air perforation with fecal peritonitis
2) Suppurative peritonitis secondary to ruptured abscess
3) Abdominal or pelvic absess (unless CT-guided aspiration is possible)
4) Fistula formation
5) Inability to rule out carcinoma
6) Intestinal obstruction
7) Failing medical therapy
8) Immunocompromised
9) Extremes of age
10) Recurrent episodes of acute diverticulitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the surgical approach for diverticulitis?

A
  • If patient has peritoneal signs, consider 2 stage Hartmann
    1) Resect inflamed colon, diverting colostomy, and closure of rectal stump
    2) Wait 3-6 months for healing of rectal stump before taking down colostomy and making a final primary anastomosis
  • If preop bowel prep is possible then do a simple resection with primary anastomosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

2 ways to remember some presentations of colorectal cancer

A

1) “Post-menopausal man with Fe deficiency anemia”
- Cancers on the right generally bleed but don’t obstruct

2) Alternating bowel habits/pencil thin stools
- Cancers on the left generally obstruct but don’t bleed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Prevalence of CRC

A

3 most diagnosed malignancy and #2 leading cause of cancer death in men and women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Screening for CRC

A

Start at age 50

Colonoscopy every 5-10 years

OR

double contrast barium enema every 5 years

OR fecal occult blood + flex sig every 5 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Risk factors for CRC

A

1) Environment - high fat, low fiber diet and cigarette smoking
2) Crohns and UC
3) Previous colorectal, breast, ovarian, uterine cancer

4) Genetic
- FAP (100% will have cancer by 30s or 40s) so treated with total proctocolectomy. In FAP we also see gastric, duodenal polyps, and periampullary cancers

  • Gardners - skull and desmoid tumors
  • Turcots - brain tumors
  • HNPCC “Lynch” - 80% chance of CRC. Higher risk for endometrial, stomach, and ovarian
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Polyps

A

Benign: hyperplastic, hamartomas, inflammatory. P-J and juvenile polyps unlikely to become malignant

Malignant potential: adenomatous. Tubular, villous (bad), tubulovillous. Pedunculated. Sessile (bad)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Presenting symptoms for CRC

A

Blood in stool: Melena if in right colon which can be detected by guaiac. Possible hematochezia is very distal.

Anemic symptoms and labs: Tired, dizzy, microcytic anemia

Weight loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ddx for heme-positive blood

A

1) Diverticular disease
2) Colon carcinoma
3) IBD
4) benign polyps
5) vascular ectasia
6) ischemic colitis
7) rectal ulcers
8) hemorrhoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Lymphatic drainage for CRC

A

Found in colonic mesentery, mesorectum and para aortic area

Low lying cancer in anal canal can go to deep inguinal nodes and tumors of the anus may spread to superficial inguinal nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Staging for CRC

A

LFTs to check for liver mets

Rectal exams, abdominal/pelvic CT for finding mets

Endorectal US for staging local tumors and finding out depth of invasion

TMN

T1 = submucosa
T2 = muscularis propria
T3 = Subserosa
T4 = other organs
N1 = mets to 1-3 nodes
N2 = 4 or more

Stage 1: T1-2 N0 M0 5yr = 90%

Stage 2: T3-4 N0 M0 5yr = 75%

Stage 3: Any T N1-N3 M0 5yr=50%

Stage 4: Any T Any N M1 5yr 5%

Untreated liver mets have median survival of less than 1 year. If treated surgically there’s 30-40% 5 year survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Surgical tx for CRC

A

Single lesion - segmental resection with 2cm margin

Synchronous lesion - hemicolectomy or sigmoid colectomy

Role of laproscopy is up in the air

Bowel prep

  • mechanical prep (clear liq 24hrs, lyte solution and enema)
  • intraluminal antibacterial (neomycin, metronidazole)
  • parenteral antibiotics 30mins before incision
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Chemo for CRC

A

Stage 3 patients and some stage 2

6 months 5FU and leucovorin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Radiation for CRC

A

Stage 2 or 3 rectal cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Follow-up for CRC

A

CEA preOp. Follow it postop to determine recurrence

PET in pts with known recurrent disease to the liver

H&P should be done every 3 months for 2 years then every 6 months for 5 years

CEA q3m x 2yrs then q6m x 5yrs

Colonoscopy 1y postop and 3-5 yrs if negative for polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How does the colonoscopy alter follow-up for suspected CRC?

A

If it finds polyp…get the path

1) benign: Now q5-7yrs (in case you missed one the first time)

2) Carcinoma in situ. Get CT for staging, resect primary, and FOLFOX
- come back for colonoscopy q3-5y

If the scope showed giant fungating mass then get CT for staging, resect primary, and FOLFOX. Scope 1 yr postop and q3-5y after

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

FOLFOX

A

FOLinic acid (leucovorin)

F = 5FU

OXaliplatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Colon embryo

A

Midgut = up to mid-transverse

Hindgut = rest to prox anus

Ectoderm = distal anus

Dentate line = transition from hindgut to ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Blood supply to colon

A

Based on embryo

Midgut = SMA

Hindgt = IMA

Distal anus = internal pudendal branches (branch of internal iliac)

Internal iliac = middle and distal rectum via middle rectal and inferior rectal arteries (branch of internal pudendal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Widest part of colon

A

Cecum…narrows progressively after that

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which parts of the colon are retroperitoneal?

A

Ascending colon, descending colon, posterior hepatic and splenic flexures (all but cecum, transverse and sigmoid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Watershed areas of colon

A

Ileocecal area

Junction of descending and sigmoid

Splenic flexure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Lymphatic drainage of colon

A

Colon, rectum and anus generally follow arterial supply (ileocolic nodes, superior mesenteric nodes, etc)

Anal canal above dentate line = inferior mesenteric node

Lower anal canal = inguinal nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Microbio of colon

A

Colon sterile at birth

Normal flora = 99% anaerobic (Bacteroides)

1% aerobic (E Coli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

IBS

A

Abnormal state of intestinal motility modified by psychosocial factors for which no anatomic cause can be found

Often a wastebasket diagnosis for a change in bowel habits with ab pain after other causes have been ruled out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Constipation

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Diarrhea definition

A

Passage of > 3 loose stools/day

In hospitalized patient, a workup may be indicated to rule out infectious or ischemic causes

In outpatient, diarrhea may occur due to extensive small bowel resection (short bowl syndrome), due to disruption of innervation, or even as an expected outcome (gastric bypass)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Diagnosis of diarrhea

A

Stool sample for enteric pathogens and C Dif toxin

Check stool for WBCs (IBD or infectious colitis), RBCs without WBCs (ischemia, invasive infectious diarrhea, cancer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Treatment of diarrhea

A

Individualized based on treatable cause, and is addressed with specific problems that may cause it (colitis, ischemia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Postvagotomy diarrhea

A

In 20% of patients after truncal vagotomy

Denervation of extrahepatic biliary tree and small bowel leads to rapid transit of unconjugated bile salts into colon

This impedes water absorption and causes diarrhea

Cholestyramine is the tx. If it fails, surgical reversal of a segment of small bowel to prolong transit time and increase absorptive capacity may be needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Pseudomembranous colitis def

A

An acute colitis characterized by formation of adherent inflammatory exudate overlying the site of mucosal injury

Most common due to overgrowth of C Dif (gram positive, anaerobic, spore-forming bacilis)

Typically occurs after broad spectrum antibiotics (esp clinda, ampicillin, cephalosporin) kill normal intestinal flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Signs of Pseudomem colitis

A

Vary from self-limited diarrhea to invasive colitis with megacolon or perforation as complications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Dx of of pseudomem colitis

A

Detection of c dif toxin in stool; proctoscopy or colonoscopy if dx uncertain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Tx of pseydomem colitis

A

Stop offending antibiotic

Give flagyl or vanc PO (if patient can’t tolerate PO give IV metronidazole)

Put patient on contact iso

High rate of recurrence (20%) despite high response rate to treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Radiation-induced colitis

A

Associated with XRT to pelvis usually for endometrial, cervical, prostate, bladder or rectal cancer

Risk = atherosclerosis, diabetes, HTN, old age, adhesions from previous surgery

Chance of getting it is dose-dependent:
6,000 = Most

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Signs of radiation induced colitis

A

Early (during course of XRT): n/v, cramps, diarrhea, tenesmus, rectal bleeding

Late (weeks to years after): tenesmus, bleeding, abscess, fistula involving rectum (rectal pain, stool per vagina)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Dx of radiation-induced colitis

A

Early = Plain abdominal film, barium enema

Late = Barium enema, CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Cause of radiation-induced colitis

A

Early = mucosal edema, hyperemia, acute ulceration

Late = submucosal arteriolar vasculitis, microvascular thrombosis, wall thickening, mucosal ulcerations, strictures, perforation

46
Q

Tx of radiation-induced colitis

A

Early = treat symptoms
if no improvement, decrease dose of XRT or D/C treatment

Late = treat with stool softener, topical 5-ASA, corticosteroid enema

  • strictures = gentle dilation or diverting colostomy after excluding cancer
  • Rectovaginal fistual = prox colostomy and low colorectal anastomosis or coloanal temporary colostomy
47
Q

ischemic colitis definition

A

Acute or chronic intestinal ischemia secondary to decreased intestinal perfusion or thromboembolism

Embolus or thrombus of IMA

Poor perfusion of mucosal vessels from arteriole shunting or spasm

Often affects the splenic flexure

48
Q

Ischemic colitis incidence and risk factors

A

Most common in elderly

Risk:

1) Old age
2) s/p AAA repair (early postop)
3) HTN
4) CAD, AFib
5) Cocaine abuse
6) Prothrombotic conditions
7) Sickle cell anemia

Most common setting for ischemic colitis is early postop period following AAA repair when impaired blood flow through IMA may put colon at risk

49
Q

Signs of ischemic colitis

A

Mild lower abdominal pain and rectal bleeding, classically after AAA repair

Pain more insidious in onsert than small bowel ischemia

50
Q

Diagnosis of ischemic colitis

A

Clinical Hx

Plain abdominal XR - may reveal pneumatosis (air in bowel wall) or thumbprinting (submucosal edema)

CT - may show segmental thickening of bowel wall

Colonoscopy may show pale mucosa with petechial bleeding

51
Q

Tx of ischemia colitis

A

If mild = IVF and observe

If mod (fever and high WBC) = IV Abx

Severe (peritoneal signs) = exlap with colostomy

52
Q

Ulcerative colitis def

A

Inflammation confined to mucosal layer of colon that extends from rectum proximally in continuous fashion. Autoimmune

53
Q

Incidence of UC

A

Age btw 15-40 and 50-80 (bimodal)

Whites 4x > blacks

Industrialized&raquo_space; developing nations

54
Q

Risks for UC

A

1) Jewish
2) White
3) Urban dwelling
4) Positive FHx
5) Nicotine LOWERS risk (unlike Crohn’s)

55
Q

Signs of UC

A

Mild (confined to rectum or rectosigmoid): intermittent rectal bleeding, passage of mucus from rectum, mild diarrhea

Mod: Freq loose, bloody stools. Mild abdominal pain, low-grade fever

Severe: Freq loose stools, severe abdominal pain, bleeding necessitates blood transfusion. Patients may have rapid weight loss

56
Q

Dx of UC

A

Flex Sig with histolopathologic eval of biopsies

Barium enema: “Lead Pipe” appearance of colon due to loss of haustral folds, but no longer test of choice

57
Q

Treatment of UC

A

Medical: Similar to Crohn’s

1) Mild/Mod = 5-ASA, corticosteroids PO or per rectum.
2) Severe = IV steroids
3) Proctitis = topical steroids
4) Refractory = immunosuppresion

Surgical
1) Indication = failure of medical therapy, increasing risk of cancer in long-standing disease, bleeding, perforation

2) Procedure = Proctocolectomy (curative)
3) If patient is acutely ill and unstable due to perf, a diverting loop colostomy is indicated. Once stabilized, the patient may undergo more definitive procedure
4) In Chrohns, the treatment is stricturoplasty and segmental resections bc recurrence is the rule and the goal is to preserve as much healthy intestine as possible

58
Q

Prognosis for UC

A

1-2% risk of cancer at 10 years and 1%/year after that

59
Q

Crohn’s vs UC complications

A

UC

1) Perf
2) Stricture
3) Megacolon
4) Cancer

Crohns

1) Abscess
2) Fistula
3) Obstruction
4) Cancer
5) Perianal disease

60
Q

Is the diverticula in diverticulitis/osis true or false?

A

False (only mucosa really)

61
Q

1 site of diverticulitis?

A

Sigmoid colon

Lower odds as you move proximally

62
Q

Lower GI Bleed

A

Bleed distal to ligament of Treitz

Massive = 3+ units of blood within 24h

Most common causes are diverticulosis and angiodysplasia

Other causes are cancer, IBD, ischemic colitis, hemorrhoids

10-20% eventually require surgery despite the fact that 85% initially stop spontaneously

Significant surgery needed when no site identified in an unstable patient bc although

63
Q

Incidence of diverticulosis vs angiodysplasia

A

Diverticulosis
50% of patients are > 60

Angio
25% are > 60
Men > women

64
Q

Character of GI bleeds from diverticulosis vs angiodysplasia

A

Divertic
Painless
> 60% site of bleeding proximal to splenic flexure
Massive and rapid

Angio
Cecum and ascending colon
Slow

65
Q

Signs of bleeding from diverticulosis vs angiodysplasia

A

Both

Melena and/or hematochezia with symptoms of orthostasis

66
Q

Diagnosis of diverticulosis vs angio

A

1) first, rule out upper GI bleed with NG lavage

2) To ID site of bleed,
- Colonoscopy
- if >0.5ml/min: bleeding san with Tc-sulfer colloid identifies bleeding. Label lasts up to 24h so patient can be easily rescanned when rebleeding occurs agter negative initial scan
- If >1ml/min angiography (selective mesenteric angio is best method to diagnose angiodysplasia)

67
Q

Treatment of bleeds from diverticulosis vs angio

A

1) Resuscitation
2) Therapeutic options if site is ID’d:
- Octreotide
- Embolization
- Vasoconstriction (Epi)
- Vasodestruction with alcohol or sodium compounds
- Coag/cautery with heat

3) If site ID’s but bleeding massive or refractory - segmental colectomy
4) Without ID of bleeding and persistent bleeding in unstable patient, exlap with possible colectomy w/ ileostomy

68
Q

Cause of angiodysplasia

A

Chronic intermittent obstruction of submucosal veins secondary to repeated muscular contractions

This results in dilated venules with incompetent precapillary sphincters and thus AV communication

69
Q

Large bowel obstruction incidence

A

Mostly in elderly patients

Much less common than SBO

70
Q

3 most common causes of LBO

A

1) Adenocarcinoma (65%)
2) Scarring secondary to diverticulitis (20%)
3) Volvulus (5%)

71
Q

Signs of LBO

A

Abdominal distention, cramping abdominal pain, nausea, vomiting, obstipation and high-pitched bowel sounds

72
Q

Dx of LBO

A

Supine and upright XR - distended proximal colon, air-fluid levels, no distal rectal air

Establish 8-12h history of obstipation; passage of some gas or stool indicated partial SBO, a nonoperative condition

Barium enema - may be needed to distinguish btw ileus and pseudo-obstruction

73
Q

Tx of LBO

A

1) Correct fluid and lyte issues
2) NG tube for intestinal decompression (gastric emptying is reflexly inhibited)
3) Broad-spectum IV Abx (Cefoxitin)
4) Relieve obstruction surgically (colonic obstruction is surgical emergency since NG tube will not decompress the colon)

74
Q

Volvulus def

A

Rotation of a segment of intestine about its mesenteric axis; characteristically occurs in sigmoid colon (75% of cases) or cecum (25%)

75
Q

Incidence of volvulus

A

More than 50% of cases are in patients over 65

76
Q

Risk factors for volvulus

A

1) Elderly (esp institutionalized patients)
2) Chronic constipation
3) Psychotropic drugs
4) Hypermobile cecum secondary to incomplete fixation during intrauterine development (cecal volvulus)

77
Q

Signs of volvulus

A

LBO

78
Q

Diagnosis of volvulus

A

Clinical presentation

Abdominal films - markedly dilated sigmoid colon or cecum with a “kidney bean” appearance

Barium enema - characteristic, “bird’s beak” at areas of colonic narrowing

79
Q

Treatment of volvulus

A

Cecal

  • R hemicolectomy if vascular compromis
  • cecopexy otherwise adequate (suture right colon to parietal peritoneum)

Sigmoid

  • Sigmoidoscopy with rectal tube insertion to decompress the volvulus
  • Emergent laparotomy if sigmoidoscopy fails or if strangulation or perforation is suspected
  • Elective resection in same hospital admission to prevent recurrence (nearly 50% of cases recur after nonoperative reduction)
80
Q

Psuedo-obstruction (Ogilvie) def

A

Massive colonic dilation without evidence of mechanical obstruction

81
Q

Incidence of Ogilvie

A

More common in older, institutionalized patients

Associated with any severe acute illness, neuroleptics, opiates, malignancy, and certain metabolic disturbances

Risk = recent surgery or trauma, severe infection

82
Q

Signs of Ogilvie

A

Marked abdominal distention with mild abdominal pain and decreased or absent bowel sounds

83
Q

Diagnosis of Ogilvie

A

Abdominal XR with massive colonic distention

Exclude mechanical cause for obstruction with water-soluble contrast enema and/or colonoscopy

84
Q

Treatment of Ogilvie

A

NGT and rectal tube for prox and distal decompression

Correction of lytes

D/C narcotics, anticholinergics, or other offending meds

Consider pharm decompression with neostigmine (cholinesterase inhibitor)

If peritoneal signs develop, patient should get prompt exlap to treat possible perf

Refractory cases may need total colectomy

85
Q

Malignant potential of a polyp

A

By size, histo type, and epithelial dysplasia

1) Size
2cm = 40%

2) Histo
Tubular = 5%
Tubulovillous = 20%
Villous = 40%

3) Atypia
Mild = 5%
Mod = 20%
Severe = 35%

86
Q

Hamartomatous polyp

A

normal tissue arranged in abnormal config - juvenile polyps and Peutz-Jeghers

87
Q

Adenoma - carcinoma sequence

A

Normal - hyperproliferative - early adenoma - intermediate adenoma - late adenoma - carcinoma (- mets)

1) APC gene loss or mutated
2) Loss of DNA methylation
3) Ras mutation
4) Loss of DCC gene
5) Loss of p53

88
Q

Hemorrhoids

A

Prolapse of submucosal veins located in the L lateral, R anterior, R posterior quadrants of anal canal

Classified by type of epithelium: I

1) Internal = covered by columnar mucosa (above dentate)
2) External = anoderm (below dentate)
3) Mixed = both types involved

Men = Women

Risk = Constipation, pregnancy, increased pelvic pressure (ascites, tumors), portal HTN

Dx = Clinical Hx, PE, visualize with anoscope

89
Q

Anal fissure definition

A

Painful linear tears in anal mucosa below dentate line; induced by constipation or excessive diarrhea

90
Q

Signs of anal fissure

A

Pain with defecation
Bright red blood on toilet tissue
Markedly increased sphincter tone and extreme pain on DRE
Visible tear upon gentle lateral retraction of anal tissue

91
Q

Tx of anal fissure

A

Sitz bath

Fiber supplements, bulking agents

Increased fluid intake

If nonsurg therapy fails, options include lateral internal spincterotomy or forceful anal dilation

92
Q

Grading internal hemorrhoids

A

1) Grade 1
- protrudes into lumen, no prolapse
- sx = bleeding
- tx = nonresectional measures (rubber band ligation, infrared coag, injection sclerotherapy - all this is only above dentate line)

2) Grade 2
- prolapse with straining, spontaneous return
- sx = bleeding, perception of prolapse
- tx = nonresectional

3) Grade 3
- prolapse, requires manual reduction
- sx = bleeding, prolapse, mucous soilage, pruritis
- tx = consider trial of nonresctional; may require excision

4) Grade 4
- prolapse cannot be reduced
- sx = bleeding, prolapse, mucous soilage, pruritis, PAIN (if thrombosed or ischemic)
- tx = excision

93
Q

Anorectal fistula definition

A

Tissue tracts originating in the glands of the anal canal at the dentate line that are usually the chronic sequelae of anorectal infections, particularly abscesses

94
Q

Classifying anorectal fistulas

A

1) Intersphincteric (#1) - tract stays within intersphincteric plane
2) Transsphincteric - fistula connects the interspincteric plane with the ischiorectal fossa by perforating the external sphincter
3) Suprasphincteric - similar to trans but fistula loops above external sphincter to penetrate the levator ani muscles
4) Extrasphincteric - fistula passes from rectum to perineal skin without penetrating sphincteric complex

95
Q

Goodsall’s rule

A

Useful to help predict course of anorectal fistula tract

Draw a line that bisects anus in the coronal plane

Fistulas that start out anterior to the line will course anteriorly in direct route

Fistulas that start out posterior to the line will have a curved path

If the tracts diverge from this rule this raises suspicious for IBD

96
Q

Anorectal abscess def

A

Obstruction of anal crypts with resultant bacterial overgrowth and abscess formation within the intersphincteric space

97
Q

Risk for anorectal abscess

A

Constipation/diarrhea/IBD

Immunocompromise

Hx of recent surgery or trauma

Hx of colorectal carcinoma

Hx of previous anorectal abscess

98
Q

Signs and tx for anorectal abscess

A

Rectal pain, often sudden onset

Associated fever, chills, malaise, leukocytosis, and a tender perianal swelling with erythema and warmth of overlying skin

Tx = surgical drainage

99
Q

Signs of anorectal fistula

A

Recurrent or persisten drainage that becomes painful when one of the tracts becomes occluded

100
Q

Dx of anorectal fistula

A

Bidigital rectal exam

Anoscopy

If internal opening cannot be identified by direct probing, it should be identified by probing the external opening or by injecting a mixture of methylene blue and peroxide into the tract

101
Q

Tx of anorectal fistula

A

Intraoperative unroofing of entire fistula tract with or without placement of setons (heavy suture looped through the tract to keep it patent for drainage and to stimulate fibrosis)

102
Q

Pilonidal disease def

A

Cystic inflammatory process generally occuring at or near the cranial edge of gluteal cleft

From trauma to hair follicles and resultant infection

103
Q

Incidence of pilonidal disease

A

Mostly young men in late teens to third decade

104
Q

Signs of pilonidal disease

A

Can present acutely as an abscess (fluctuant mass) or chronically as a draining sinus with pain at the top of the gluteal cleft

105
Q

Tx of pilonidal disease

A

I/D under local anesthesia with removal of involved hairs

106
Q

Anal cancer incidence

A

rare

1-2% of colon cancers

107
Q

Risk for anal cancer

A

HPV

HIV

Cigarette smoking

Multiple sexual partners

Anal intercourse

Immunosuppressed

108
Q

Signs of anal cancer

A

Often asymptomatic

Can present with anal bleeding, a lump, or itching; an irregular nodule that is palpable or visible externally (anal margin tumor) or a hard, ulcerating mass that occupies a portion of the anal canal (anal canal tumor)

109
Q

Dx of anal cancer

A

Surgical bx with histo eval

Histo: Anal margin tumors include SCC and BCC, Paget’s ,and Bowen’s. (pagets = adeno in situ, Bowen’s = SCC in situ)

Anal canal tumors are usually epidermoid (SCC or transitional cell/cloacogenic carcinoma) or malignant melanoma

Clinical staging = involves history, PE, proctocolonoscopy, abdominal or pelvic CT or MRI, CXR and LFTs

110
Q

Tx of anal cancer

A

Epidermoid: Chemoradiation is mainstay (5-FU, mitomycin C, 3000 cGy XRT - Nigro protocol)
- surgery reserved for recurrence

Other anal margin tumors: wide local excision alone or in combo with radiation and/or chemo works 80% of the time without abdominal-perineal resection if tumor is small and not deeply invasive

Anal canal tumors: local excision not an option; combined chemo (5FU and mitomycin C) with radiation is often successful; abdominal-perineal resection only if follow up bx indicates residual tumor

111
Q

Prognosis of anal cancer

A

Anal margin tumors = 80% 5yr

Anal canal

  • epidermoid = 50%
  • malignant melanoma = 10-15%

Surgery (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions