Lecture 4

Question 1

What are the 2 functions of colon and rectum?

Answer 1

Absorption of water, electrolytes​
Storage of feces​

Question 2

What connects venous drainage of the rectum?

Answer 2

Venous cushions or hemorrhoids

Question 3

List some diagnostics for the colorectal region

Answer 3

Digital rectal exam​ (DRE)
Colonoscopy: routine after 45​yo
Abdominal series (XR): pneumoperitoneum, obstruction, volvulus​
Contrast studies​
CT scan​
Angiography/nuclear study

Question 4

Descr diverticulosis and its symptoms

Answer 4

1) Multiple false diverticula of colon
Most commonly in sigmoid
80%asymptomatic finding on colonoscopy or CT
2) Usually asymptomatic
may have LLQ pain, change in bowel habits, bleeding

Question 5

How is diverticulosis treated?

Answer 5

No treatment required if asymptomatic
No evidence that dietary changes treat or prevent

Question 6

Diverticulitis
1) What is it?
2) Sx?
3) Dx?

Answer 6

1) Obstructed, inflamed diverticula (micro- or macro-perforation)
2) Progressive abd pain (usually LLQ), change in bowel habits, low-grade fever, +/-N/V
3) CTA/Pw IV contrast (preferredinitial study), BE, scope later (4-6 wks after Tx)

Question 7

Diverticulitis: Differentiate outpatient vs inpatient Tx

Answer 7

1) Outpatient (uncomplicated): Supportive (pain control, clear liquid diet, clinical reassessment until resolved, +/-abx)
2) Inpatient (complicated): >3cm abscess, fistula, obstruction, or perforation (Meet one or more criteria): IV antibiotics, IV analgesia, IV hydration, bowel rest

Question 8

What are some complications of diverticulitis?

Answer 8

Free (frank) perforation, obstruction, abscess, fistula

Question 9

Diverticulitis:
1) How common is surgery?
2) What does choice of surgery technique depend on?

Answer 9

1) <10%% require surgery; leading cause (elective)
2) Hemodynamic stability
Extent of peritoneal contamination
Extent of colonic inflammation
Surgeon experience/preference

Question 10

Diverticulitis: What should you do for Localized perforation (Hinchey I & II) forming a pericolonic, mesenteric, or pelvic abscess?

Answer 10

Medical therapy +/- drained percutaneously
Abscesses >3cm should be evaluated for percutaneous drainage

Question 11

Diverticulitis:
1) What should you do for Free (frank) perforation (Hinchey III & IV)?
2) What should you do if there’s an obstruction?

Answer 11

1) Life-threatening condition requiring emergency surgery
2) Resection (or fecal diversion) required to rule out cancer & relieve obstruction; endoluminal stenting

Question 12

Diverticulitis: What should you do for persistent Sxs?

Answer 12

Surgery required for failure of medical treatment & recurrent symptoms after recovery (chronic smoldering diverticulitis)

Question 13

Describe how to decide if Elective (risk reduction) surgery should be done for diverticulitis

Answer 13

1) Individualized decision for sigmoid colectomy
2) Based on # episodes, severity of symptoms, impact on quality of life, comorbidity, anatomic factors, access to medical resources, chance of recurrence, and patient preference
ie. prior episode of complicated diverticulitis and immunosuppressed
3) Typically performed 10-12 weeks after recovery

Question 14

Diverticulitis surgery:
1) Descr the use of abx
2) Descr bowel prep

Answer 14

1) Most common organisms: E. coli, K. pneumoniae, and B. fragilis
-Prophylactic abx within 1hr of surgery
2) Bowel prep recommended for all elective resection colorectal procedures (and stable Hinchey 1 &2 if requiring surgery)

Question 15

Diverticulitis surgery:
1) Descr stoma marking
2) What pt position is surgery done in?

Answer 15

1) Stoma: surgically created opening in the abd wall connecting bowel with outside of the body
Ex. Colostomy, ileostomy, urostomy
2) Patient positioning: modified lithotomy or split-leg position

Question 16

Descr elective Sigmoid colectomy/ resection with primary anastomosis for diverticulitis

Answer 16

One-stage resection
Performed open or minimally invasive (laparoscopic or robotic)
Goal: remove diseased colon and perform primary anastomosis of healthy remaining bowel

Question 17

Descr emergent 2-stage Hartmann’s procedure for diverticulitis

Answer 17

Gold standard
Most commonly performed for Hinchey III &IV

Question 18

Colorectal cancer:
1) How common?
2) When is it diagnosed?
3) Where does it occur most?
4) In what ages is it seen?

Answer 18

1) ~53,000 deaths & ~153,000 new cases annually
2) Diagnosed after onset of symptoms, asymptomatic screening, or emergency admission
3) More occur on lower left side
4) qPeak at 70, start in 4th decade

Question 19

What are some risk factors for CRC?

Answer 19

familial polyposis, Lynch syndrome, UC, Crohn’s, polyps, DM, truncal obesity, red/processed meat consumption, smoking, etoh consumption

Question 20

Colorectal cancer:
1) What do most cases arise from?
2) Descr this
3) When are these at increased risk?

Answer 20

1) Adenomatous colon polyps: Progress from small (<8 mm) to large (≥8 mm) polyps then to dysplasia and carcinoma.
2) Adenomas (adenomatous polyps) increase risk for CRC and may harbor malignancy/progress to malignancy
-Subtypes: tubular, tubulovillous (22% progress), villous (40% progress)
3) Size: 1-2cm (10% risk), >2cm (45% risk)
-Sessile, located on ascending colon, male, >60yo, FHx

Question 21

What should be done if a pt has an adenomatous colon polyp?

Answer 21

Complete excision of adenoma + more frequent colonoscopic surveillance

Question 22

1) How long does it take adenomas to grow into CRC?
2) What are some Sxs of right sided lesions?

Answer 22

1) Adenocarcinomas grow slowly
Adenoma > carcinoma takes ~10yrs
2) May cause chronic blood loss resulting in iron deficiency anemia (fatigue, weakness)

Question 23

CRC: What are some Sxs of left-sided lesions?

Answer 23

Frequent circumferential involvement:
-Possible obstruction
-Colicky abdominal pain
-Change in bowel habits (constipation, frequency, loose stools)
-Possible blood-streaked stools (marked bleeding unusual)

Question 24

Rectal cancer:
1) What are some Sxs?
2) Descr the physical exam

Answer 24

1) Tenesmus, urgency, recurrent hematochezia
2) Physical exam usually normal (except in advanced disease)
-Liver should be examined for hepatomegaly (metastasis)
-Distal rectal cancers
-Digital rectal exam (DRE) to determine extension

Question 25

What are some labs for CRC?

Answer 25

CBC: anemia CMP Hepatic function: increased alkaline phosphatase CEA: for proven cancer and surveillance after treatment (not approved for screening)

Question 26

How is CRC detected? (2 ways)

Answer 26

Colonoscopy (gold standard for CRC detection) CT colonography (“virtual colonoscopy”): if unable to reach cecum or tumor precludes passage of colonoscope

Question 27

Explain TNM staging for CRC

Answer 27

T - primary tumor (depth) N - status of the regional nodes M - distant metastasis Correlates with the patient’s long-term survival Used to determine which patients should receive neoadjuvant therapy or surgery

Question 28

T, N, & M categories for colon cancer are assigned based upon what?

Answer 28

Whether there are signs of cancer spread on physical examination or radiographic imaging tests *Findings from surgical resection and histologic examination of the resected tissues

Question 29

Descr supplemental approaches for staging rectal cancer

Answer 29

DRE Rigid proctoscopy MRI & ERUS

Question 30

How is colon cancer treated? Explain

Answer 30

Surgical resection + adjuvant chemotherapy: 1) Resection of the primary colonic or rectal tumor + anastomosis 1) Resection of all draining mesenteric lymph nodes: -At least 12 to determine staging -Guides decisions about adjuvant therapy

Question 31

CRC: 1) Descr the use of surgical resection 2) Who are candidates for curative surgery?

Answer 31

1) For treatment & staging 2) Stage I-III Stage IV with resectable metastasis to liver and/or lung

Question 32

What surgical technique is preferred for most CRC pts? Explain

Answer 32

Minimally invasive: First step: explore abdominal cavity for mets Resection of 5 cm on each side of lesion Adequate lymphadenectomy: 12 or more lymph nodes

Question 33

What are the 3 surgical options for obstructing (worse prognosis) colon cancers?

Answer 33

1) Diversion 2) Urgent resection with or without anastomosis 3) Endoscopic stenting with or without resection during same hospitalization

Question 34

Besides surgery, what should be done for obstructing (worse prognosis) colon cancers?

Answer 34

+ Adjuvant chemotherapy: standard of care for stage III (node-positive) disease (improves survival 20-25% and reduces recurrence by 40%) -Considered in high-risk stage II -Start immediately upon recovery from surgery (~1 month post-op) (Adjuvant radiation rarely used)

Question 35

Rectal CA: 1) How do you Tx stage 1? 2) What abt stages 2-3?

Answer 35

1) Surgical excision (no benefit from chemo or radiation therapy) 2) Benefit from combined therapy: a) Neoadjuvant chemoradiation, surgery, & adjuvant chemo or… b) Short-course radiation, surgery, & adjuvant chemo or… c) Total neoadjuvant therapy (chemo + chemoradiation or radiation followed by surgery)

Question 36

Rectal CA: How do you Tx resectable stage IV & asymptomatic primary tumors?

Answer 36

-Neoadjuvant chemo & either chemoradiation or short-course radiation followed by surgery -Watch & wait approach

Question 37

What are the factors considered in choice of surgery for rectal CA?

Answer 37

1) Lesion location, depth of penetration & invasion into adjacent structures 2) Patient’s individuality 3) Patient preference

Question 38

Descr timing of surgery for rectal CA based on the stage

Answer 38

1) Stage I: proceed directly to surgery 2) Stages II, III, & resectable stage IV: neoadjuvant therapy then surgery

Question 39

1) When is local excision appropriate? 2) What are the radical options?

Answer 39

1) Early-stage disease for pathologic staging & definitive treatment for some 2) LAR or APR + TME

Question 40

Radical excision for rectal CA: 1) When is Low anterior resection (LAR) used? 2) When is Abdominoperineal resection (APR) used? 3) What is Total mesorectal excision (TME)? When is it used?

Answer 40

1) Tumors in mid- to distal rectum 2) Tumors in distal third of rectum and/or involving anal sphincter 3) Removal of the rectum and fatty tissue, lymph nodes, and blood vessels surrounding it. Gold standard for tumors of the middle and lower rectum

Question 41

Colorectal CA: 1) Descr Metastatic disease 2) What are some palliative procedures?

Answer 41

1) Liver most common site; liver & lung metz resectable if all other sites amenable to oncologic resection 2) Fecal diversion, surgical bypass, endoluminal stents

Question 42

What are the Txs for recurrent CRC? (2 main options)

Answer 42

1) Resectable: surgery + chemo + radiation therapy 2) Unresectable: combo chemo & radiation therapy

Question 43

Diseases of anus and rectum: 1) Common Sxs? Common complaint? 2) Decr what you may find on inspection 3) What abt on digital exam?

Answer 43

1) Pain, protrusion, bleeding, discharge Hemorrhoids are a common complaint -Must examine but be gentle 2) Fissures, skin tags, hemorrhoids, fistulae, tumors, dermatologic or infectious conditions 3) Tumors, polyps, sphincter weakness

Question 44

1) Define rectum 2) Define anus 3) Where is there sensation?

Answer 44

1) Rectum: approximately 15 cm in length 2) Anus: 3-4 cm from dentate line to anal verge 3) Above dentate line - insensate Below dentate line - sensate

Question 45

Anorectal abscess: 1) What is it? 2) S/Sxs?

Answer 45

1) Local infection of perirectal spaces secondary to obstruction of anal glands & ducts 2) Acute anal pain, swelling, +/-fever

Question 46

Anorectal abscesses: 1) What are some exam findings? 2) How is it diagnosed?

Answer 46

1) Exam: erythematous tender, fluctuant mass adjacent to anal canal 2) Not necessary but MRI helpful (and imaging test of choice) if no obvious PE findings or if abscess recurrent/complex (ie Crohns)

Question 47

Anorectal abscesses: 1) How are they treated? 2) What is a complication?

Answer 47

1) Incision & drainage (I&D) for ALL abscesses Abx for immunocompromised or septic If larger abscess, may require drain 2) Anal fistula (aka fistula-in-ano)

Question 48

What followup care should you do for anorectal abscesses?

Answer 48

Pain control Laxatives or fiber supplements Sitz baths Close follow up (up to 8 weeks to heal) every week or 2

Question 49

Anal fistula: 1) What causes them? When should they be suspected? 2) What defines them?

Answer 49

1) Complication of up to 50% perirectal abscesses Suspected if persistent drainage 6-8wks after abscess drainage 2) Defined by tissues traversed and relationship to the anal sphincter (Parks classification system)

Question 50

Anal fistula: 1) What increases risk? 2) What should exam include?

Answer 50

1) PMHx of Crohn's 2) DRE, anoscopy >External opening visualized often with a palpable subcutaneous tract between the ext opening and anus If complex tracts, MRI or endorectal US

Question 51

What is Goodsall’s rule for anal fistulas?

Answer 51

Descr the relationship between internal & external openings

Question 52

Descr anal fistula Tx

Answer 52

General surgeons (simple), colorectal surgeon (complex) Traditional fistulotomy OR Sphincter-sparing approaches (trans-sphincteric; use of seton) Prone (anterior) or lithotomy (posterior) position If associated with Crohn’s, medical management (abx, biologics) is the treatment.

Question 53

What are some anal fistula complications?

Answer 53

incontinence, leakage, recurrent fistula, & abscess formation (rare)

Question 54

Rectal prolapse aka procidentia: What are the Sxs?

Answer 54

perianal mass protrudes with straining, abd discomfort, incomplete BM, mucus and/or stool discharge with altered bowel habits No pain (suggests other diagnosis if present)

Question 55

Rectal prolapse: 1) Dx? 2) What are the types?

Answer 55

1) Full thickness prolapse visible on exam when bearing down Colonoscopy to r/o other colonic pathology prior to surgery 2) Complete (protrusion of all layers), partial (protrusion of mucosa only), and occult (intussusception without protrusion).​

Question 56

Descr the Tx of rectal prolapse

Answer 56

1) Most commonly treated surgically 2) Surgical indications: presence of a mass from prolapsed bowel & fecal incontinence and/or constipation a/w rectal prolapse 3) Treatment: transabdominal or perineal surgery; Rectopexy

Question 57

Hemorrhoids: What are they?

Answer 57

Engorgement precipitated by constipation, straining, pregnancy, increased pelvic pressure (ascites, tumor), portal hypertension, diarrhea

Question 58

Differentiate internal and external hemorrhoids

Answer 58

Internal: above dentate line, graded 1-4, insensate, may cause painless BRBPR External: below dentate line, palpable lump, pain (severe when thrombosed) & pruritis

Question 59

1) Who are candidates for hemorrhoid surgery? 2) What are some outpatient procedures?

Answer 59

1) Patients with normal bowel habits & persistent symptoms: -Internal: grades 1-3 with failed conservative management; grade 4 first step -External complicated/failed medical therapy/within 4 days of thrombosis 2) Lithotomy or prone jackknife position -In office: rubber band ligation (most effective/preferred grade I-III), sclerotherapy, infared coagulation -In OR surgical treatment: Excisional hemorrhoidectomy, stapled hemorrhoidopexy, doppler-guided hemorrhoidectomy

Question 60

Hemorrhoids: 1) What should you do post-op? 2) What are some early complications? 3) What are some late complications?

Answer 60

1) Post-op pain control, keep BMs soft (fiber), avoid constipation 2) Bleeding, infection, & urinary retention 3) Anal stenosis, mucosal ectropion

Question 61

When is Stapled hemorrhoidopexy indicated? What are some complications of this procedure?

Answer 61

1) Failed medical treatment Grade II-III not a/w significant external hemorrhoids 2) Rectovaginal fistula, rectal obstruction, staple line bleeding

Question 62

Anal fissures: 1) What are they? 2) What is the typical location? 3) When should you be concerned for concern for Crohn’s, infections (TB, HIV/AIDS, syphilis), carcinoma (rare)?

Answer 62

1) Tear in anoderm distal to dentate line (acute & chronic) 2) 90% posterior midline 3) With lateral fissures

Question 63

Anal fissures: 1) Sxs? 2) What abt in chronic cases?

Answer 63

1) Sharp pain with defecation, rectal bleeding 2) Heaped up epidermis (sentinel tag)

Question 64

What is the initial treatment for anal fissures?

Answer 64

Fiber supplementation, Sitz baths; local CCB or NTG -Most patients with acute and 50% chronic are successfully treated without surgery

Question 65

Descr the two main choices for anal fissure surgery

Answer 65

1) Low risk of fecal incontinence: Procedure of choice/most common procedure performed is lateral internal sphincterotomy 2) High risk (preexisting fecal leakage or lack of sphincter control): V-Y advancement flap & subcutaneous fissurectomy

Question 66

Ischemic colitis: 1) Who does it occur in? Is it emergent? 2) What causes it?

Answer 66

1) Colon is most common site of bowel ischemia Elderly, frail Mortality 13% 2) Usually due to hypoperfusion (nonocclusive 90%) of colon secondary to hemodynamic instability Other causes: thrombosis, atherosclerosis, embolism, ligation of a major vessel

Question 67

Ischemic colitis: 1) Is it easy to Dx? 2) Where does it occur? Why?

Answer 67

1) Often transient & difficult to diagnose 2) Splenic flexure and rectosigmoid junction most commonly affected (“watershed areas”)- transition of blood supply from SMA to IMA distribution

Question 68

Ischemic colitis: 1) Classic presentation? 2) Descr the diagnostic tests

Answer 68

1) Worsening abdominal pain (out of proportion to exam), bloody diarrhea, hematochezia PMHx afib, atherosclerosis, recent trauma/surgery/severe systemic illness 2) Colonoscopy and abd CT w contrast -Colonoscopy: diagnostic modality of choice (*contraindicated in critically ill patients w peritonitis) -Abd CT: bowel wall edema/thickening or pneumatosis of intestinal wall

Question 69

Large bowel obstruction: 1) S/Sxs? 2) Etiologies?

Answer 69

1) Signs/symptoms: abd pain, distention, obstipation, nausea, vomiting (late finding) -R-sided lesions: tend to grow to a large size prior to causing obstruction bc larger diameter 2) Neoplasms (most common), diverticular disease, volvulus, IBD, ischemic or anastomotic strictures

Question 70

1) What is the most common cause for nonmechanical colonic obstruction? 2) How is LBO diagnosed? Explain

Answer 70

1) Colonic pseudo-obstruction (Ogilvie syndrome) 2) Diagnosis (stable without urgent surgical indication): plain abdominal x-ray, upright CXR, CT with rectal contrast (most useful single test for large bowel obstruction) -if concern for strangulation or perforation, use PO gastrografin (water-soluble contrast medium), barium enema, colonoscopy (for chronic symptoms)

Question 71

What are LBO Tx options?

Answer 71

Resection with primary anastomosis Resection with diversion Diversion alone Endoscopic stent placement (bridge to surgery and/or palliative)

Question 72

Volvulus: 1) What is it? 2) MC locations?

Answer 72

1) Twisting loop of colon around axis of mesentery results in a closed-loop obstruction  surgical emergency 2) Most common: sigmoid (65%), cecum, transverse

Question 73

Sigmoid volvulus: 1) Sxs? 2) Imaging findings?

Answer 73

1) Sxs: intestinal colic, nausea, obstipation, distention, chronic constipation 2) “Bent inner tube” sign on abd XR with dilated sigmoid pointing to RUQ “Bird’s beak” deformity with contrast enema “Coffee bean” sign

Question 74

Descr Sigmoid volvulus Treatment

Answer 74

1) IV fluid resuscitation and correction of electrolyte imbalances, NPO, NGT 2) If sign of ischemia, necrosis, or perforation, abx 3) If no peritonitis, detorsion/decompression via urgent endoscopy via flexible sigmoidoscope or colonoscope release of gas/stool 4) If no signs of ischemia, schedule for a sigmoid resection during same admission (recurrence common within 1yr) *If detorsion fails or has bowel ischemia/necrosis/perforation: abx + urgent laparotomy (Hartmann procedure)

Question 75

Cecal volvulus (rotation of cecum and terminal ileum around mesentery): 1) Who does it occur in? 2) Sxs? 3) Abd XR findings?

Answer 75

1) F>M, ~53yo avg. 2) Severe intermittent colicky pain of R abd  continuous pain  vomiting, distention, obstipation 3) “Coffee bean” sign with dilated cecum pointing to LUQ (may also see “bird’s beak”) Contrast enema & CT also sensitive

Question 76

Cecal volvulus: Tx?

Answer 76

Endoscopic detorsion less likely successful (and not recommended) Primary treatment: resection with right colectomy (ileocecectomy)