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Flashcards in Alimentary Tract - Anal Canal Deck (58):
1

initial treatment of SCC of anal canal

concurrent chemoradiation (Nigro protocol)

radx dose - 45 Gy

chemo - mitomycin, 5-FU

2

If an anal margin/perianal skin SCC is well-differentiated and < 2 cm, what is first line treatment?

local excision if T1 and no risk to sphincter complex

3

6 months s/p chemoradiation, a patient has biopsy proven progressive/persistent anal SCC, what is the treatment?

APR

4

the surgical anal canal is between what two landmarks

intersphincteric groove

anorectal ring (not dentate line)

5

what structure is at the anorectal ring?

levator ani - divides the rectum and anal canal

6

the intersphincteric groove is between what structures?

the internal and external anal sphincter muscles

nonkeratinized squamous epithelium and keratinized squamous epithelium (external)

7

what is the difference in the anal canal proximal and distal to the dentate line

  • Above the dentate: columnar epithelium; superior rectal artery, a branch of the inferior mesenteric artery; lymph drained along hypogastric vessels.
  • Below the dentate: stratified squamous epithelium; inferior rectal artery, a branch of the internal pudendal artery; somatic innervation; superficial inguinal lymph drainage.

8

what studies are required for staging of anal SCC?

DRE, anoscopy, superficial inguinal node palpation w/ consideration of FNA, CT chest and abdomen, MRI pelvis, consider PET/CT if positive nodes or large mass

9

what are other studies that should be considered in patients who have already been staged for SCC? 

HIV testing

in women, gyn exam should be considered to rule out HPV-associated cervical cancer

10

what is the recurrence rate for anal SCC after chemoradiation? when do you re-examine?

10-30%

wait 6 months to do biopsy (ongoing beneficial effects of radiation)

can do biopsy earlier if disease is progressing

11

for anal SCC, if there is biopsy-proven inguinal lymph node involvement, what else should be done at the time of APR

  • pts initially receive chemoradiation that covers inguinal lymph nodes (positive or not)
  • lymphadenectomy can be done during APR for pts with persistent or recurrent nodal disease
  • lymph node involvement is an independent predictor of poor prognosis

12

what procedure would you do for a well-differentiated 1 cm SCC of the anus? 

WLE +/- V-Y advancement flap or skin graft

13

what is the role of APR in anal SCC? what are the steps?

indicated for recurrent/progressing SCC 6 mo s/p chemoradiation

  • goal: resect rectum, mesorectum, anus, perineal soft tissue, pelvic floor musculature en bloc
  • abdomen: mobilize sigmoid, ID L ureter, divide sigmoid
    • high ligation of IMA
    • ​TME: circumferentx dissx in avascular plane around mesorectum, preserving autonomic nerve plexus
  • perineum: elliptical incision, dissection to ischiorectal fossa
  • end colostomy 

14

in pts w/ SCC of the anus, what can be considered to prevent perianal wound complications (dehiscence, abscess, sinus tract)?

omental flap

muscle flap reconstruction (rectus abd, gracilis, gluteal)

15

how is radiation proctitis diagnosed? what can chronic radiation proctitis cause? how is it treated?

endoscopy w/ visualization telangiectasia, atrophy, friable tissue

can cause obstruction and bleeding

treated w/ sucrulfate, topical formalin, argon plasma

16

In a patient w/ anal SCC s/p chemoradiation, evidence of progression on examination should be followed by... 

a biopsy and restaging with CT and/or PET.

Surgical treatment with an APR with or without inguinal node dissection is then indicated.

17

Surveillance of anal SCC involves evaluation by DRE, anoscopy, and inguinal lymph node palpation 8 to 12 weeks after completion of chemoradiation. At that time, patients' conditions are classified as... 

  1. complete remission - f/u w/ serial DRE, anoscopy, ILN palp, CT
  2. persistent disease - follow closely x6 mo - bx if still present
  3. progressive disease - bx, restage, APR +/- ILN dissx

18

A 51-year-old woman presents to your clinic with complaints of anal bleeding and pain. Physical examination reveals a 3-cm ulcerated anal lesion. What is your approach in evaluating this patient further?

  • Ddx: cancer, infection, trauma
  • PE: size, mobility, location in relation to sphincter, ILN
  • Dx: biopsy
  • Stage: FOBT, CT chest, MRI abd/pelvis, +/-PET/CT

19

A 64-year-old man is referred to you with squamous cell carcinoma of the anus. How would you determine the treatment plan?

  • diffx b/w anal canal vs anal margin/perianal skin
  • stage: DRE, anoscopy, MRI pelvis, CT chest/abd
    • may need ILN FNA or PET/CT
  • tx depends on stage
    • differentiated, <2cm on margin - WLE
    • Nigro treats everything else
    • APR +/- ILN dissx if chemo fails (dz s/p 6 mo)

20

define anal intraepithelial neoplasia (AIN)

premalignant to anal SCC, SCC in situ, Bowen's disease

21

exposure to what virus has been associated with the development of anal SCC

HPV

22

Other than HPV, what are other risk factors for anal SCC?

  • STDs
  • HIV
  • immunosuppression
  • smoking
  • precancerous lesions

23

What is the differential for anal canal cancer?

SCC, melanoma, adenocarcinoma, carcinoid

24

In a patient w/ a pruritic, eczematous, erythematous lesion, what is your presumptive diagnosis?

What is this associated with?

What evaluation is needed for the workup?

extramammary Paget disease

associated w/ hidden GI cancer - colonoscopy needed

25

Metastatic anal SCC is treated w/            -based chemotherapy?

cisplatin

26

Explain the indications and contraindications for fistulotomy in patients with anal fistulae.

  • Indications: 
    • Simple fistulae
    • Transsphincteric and low in location, < 1/3 of external anal sphincter
    • Intersphincteric fistulae
  • Contraindications: 
    • Complex fistulae (suprasphincteric or extrasphincteric)
    • Transsphincteric and high in location, o> 1/3 ext anal sphincter
    • Incontinence at baseline
    • Crohn fistulae

27

When examining a patient under anesthesia, be able to accurately identify both the external and internal openings of the fistula and trace the route relative to the anal sphincter complex. Identify the different types of fistulas.

  • Intersphincteric fistulae have an internal opening at the dentate line, pass through the internal sphincter only, then descend through the intersphincteric plane to open perianal.
  • Transsphincteric fistulae have an internal opening at the dentate line and then pass through both internal and external sphincters with an external opening in the ischioanal fossa.
  • Suprasphincteric fistulae have an internal opening at the dentate line, pass through the internal sphincter, ascend over the puborectalis muscle before passing through the external sphincter, and then descend into the ischioanal fossa.
  • Extrasphincteric fistulae have internal openings in the rectum above the levators, descending through the ischioanal fossa.

28

Understand the principles of fistula surgery.

  • Elimination of sepsis
  • Closure of the fistula tract
  • Preservation of the patient's fecal continence and sphincter function
  • Minimization of recurrence

29

Explain alternative treatment options for anal fistulae in patients for whom fistulotomy is contraindicated.

  • Seton
  • Anal plug
  • Fibrin glue
  • Advancement flap
  • Ligation of intersphincteric fistula tract (LIFT) procedure

30

What is the recurrence rate of an anal fistula after operative repair?

Recurrence of an anal fistula can be as high as 40%, depending on technique.

31

What preoperative preparation is important if doing an endorectal advancement flap for a fistula?

Adequate bowel preparation is important if doing an endorectal advancement flap.

32

What is the most common complication after anal fistula surgery?

The most common complication after fistula surgery is urinary retention.

33

What is the most significant risk in a perianal fistula surgery? How is it caused?

The most significant risk during fistula surgery is damage to the sphincter complex, with subsequent incontinence.

34

What does the patient need to know if a cutting seton is to be placed?

If a cutting seton is to be placed, the patient should be informed of the need to have it sequentially tightened. 

35

Key steps of anal fistulotomy.

  • ID the tract - connect the external/internal openings with a probe (don't make false passages).
  • Use methylene blue or hydrogen peroxide to identify the internal opening if difficult to probe.
  • Appreciate the tract’s relationship to the sphincter complexes - maximize sphincter preservation.
  • Feel the amount of muscle overlying the probe prior to dividing the isolated tissue.
  • It is acceptable to divide the internal sphincter; divide as little external sphincter as possible.
  • Marsupialize the edges of the wound once the fistula has been opened.
  • If a fistulotomy cannot be performed because of sphincter involvement, place a seton.
  • It is placed through the established fistula tract and secured in place.
  • The patient will be followed for tightening.

36

Explain the key steps of an endorectal advancement flap for anal fistula.

  • Fistulectomy—excision of the fistula tract
  • Mobilization of a mucosal flap
  • Coverage of the internal opening without tension
  • Close with absorbable suture

37

Explain the key steps of a ligation of the LIFT procedure for treatment of transsphincteric fistulae (involves the internal sphincter).

  • Identify the internal opening.
  • Make an incision in the intersphincteric plane at the site of the fistula.
  • Identify the intersphincteric tract using a lacrimal probe.
  • Dissect around the intersphincteric portion of the fistula tract.
  • Hook the intersphincteric tract using a small right-angle clamp.
  • Doubly ligate the tract close to the internal and external sphincter (absorbable suture), and transect between sutures.
  • Inject the external opening to confirm that the tract was divided completely.
  • Curette the external portion of the fistula tract, then drain the external opening.
  • Reapproximate the intersphincteric incision wound with absorbable suture.

38

During a fistulectomy, how would you make the decision to place a seton?

  • A transsphincteric fistula is high, involving more than one-third of the external anal sphincter.
  • The fistula is suprasphincteric or extrasphincteric.
  • The fistula is located anteriorly.
  • The fistula is related to Crohn disease and there is significant perianal sepsis and inflammation.

39

Understand the management of a horseshoe fistula.

  • This involves draining the internal opening and deep postanal space with or without a seton.
  • The horseshoe portion of the fistula should be counterdrained rather than unroofed.

40

Understand the management of simple anal fistulae in Crohn disease.

  • Asymptomatic fistulae in patients with Crohn disease do not require surgical treatment. 
  • Symptomatic, simple, low anal fistulae in patients with Crohn disease may be treated by fistulotomy.

41

Management of complex anal fistulae in patients with Crohn disease is multimodal. How is it done?

  • Surgical treatment with seton placement is followed by medical therapy with tumor necrosis factor-α inhibitors. 
  • Fecal diversion may be necessary in severe cases. 
  • Final closure of the fistula with endorectal advancement flap may be pursued only after perianal sepsis is cleared and the tissue is soft. 
  • Some patients may require permanent setons to manage their perianal fistula disease. 

42

How do you manage urinary retention postop anal fistula operation? 

  • may require catheter and urology follow up

43

How do you manage bleeding postop anal fistula operation?

If not stopping and significant, can do EUA.

Avoid packing within the canal. 

44

How do you manage fecal incontinence after an anal fistula operation?

bulking agents first, then sphincteroplasty if refractory

45

Describe the general principles of postoperative care and follow-up after anal fistula surgery.

  • Local wound care involves sitz baths.
  • Avoid packing.
  • Antibiotics are not necessary (except for patients with Crohn disease or immunocompromise).
  • High-fiber diet for up to 1 month avoids straining.
  • Serial follow-up visits are indicated for patients with cutting setons—for sequential tightening.

46

What is the difference between a closed hemorrhoidectomy and an open hemorrhoidectomy? Is one preferable over the other?

  • Open: mucosa is closed but the skin is left open.
  • Closed: skin and mucosa are both closed.
  • Post-operative pain and sphincter function are similar for both approaches, but most US surgeons use the open technique.

47

Describe the key steps of an open hemorrhoidectomy.

  • V-shaped skin incision at the location of hemorrhoidal groups, with the apex located internally at the vascular pedicle
  • Creation of a mucosal flap for dissection of additional hemorrhoidal tissue in the submucosal space.
  • Ligation of the vascular pedicle to the hemorrhoid.
  • Adequate mobility of the mucosal flap to prevent stenosis and closure of mucosa.

48

What are the complications of hemorrhoidectomy?

  • Bleeding, either early or delayed.
  • Urinary retention.
  • Postoperative fissure (rare).
  • Infection (rare).
  • Long-term incontinence (rare).
  • Anal stenosis (rare).

49

What are the elements of early postoperative care of the hemorrhoidectomy patient?

  • This operation is painful. The patient should be counseled pre-operatively on the expected level of pain. Provide an adequate supply of opiate analgesics.
  • Provide a stool softener regimen.
  • The patient should monitor for any post-operative bleeding or fever, and call the surgeon if either are inadequately managed.

50

How is the long-term complication of anal stenosis after hemorrhoidectomy prevented?

  • Leave an adequate bridge of mucosa between areas of hemorrhoidal excision.
  • This is most difficult to achieve in operations for fourth-degree hemorrhoids.
  • If in doubt, it is better to be conservative about the extent of excision.

51

What separates internal from external hemorrhoids?

dentate line

52

What are hemorrhoids? How can they be diseased?

Hemorrhoids are normal submucosal/vascular cushions arising from the internal sphincter.

There are no valves in the rectal veins, so hemorrhoidal cushions can fill with blood on increased pressure. Over time, hemorrhoidal supporting tissue can break down, causing potential for prolapse and engorgement.

This leads to a series of physiologic changes that result in tissue breakdown, neovascularization of the tissue, and a cyclical process of hemorrhoidal engorgement, decreased venous return, and prolapse.

53

Given a patient with internal hemorrhoidal disease, correctly stage the process according to the generally accepted four-point scale.

  • Stage 1 = prominent in the anal canal
  • Stage 2 = will prolapse but spontaneously reduces
  • Stage 3 = will prolapse but must be manually reduced
  • Stage 4 = will not reduce after prolapsing

54

Identify need for hemorrhoidectomy.

  • Patients with hemorrhoidal symptoms not amenable to conservative bowel manipulation
  • Internal hemorrhoids > stage 2 not amenable to banding
  • Symptomatic hemorrhoids with a large external component

55

Given a patient with severe hemorrhoidal disease, correctly identify the need for urgent hemorrhoidectomy.

Strangulated or gangrenous hemorrhoids need immediate attention and operative intervention.

56

Thrombosed external hemorrhoids classification and management

often stratified by length of symptoms (< or > 72 hrs)

  • early presentation—definitive management is excision, as it results in more rapid symptom resolution and lower recurrence.
  • late presentation—typically nonoperative (sitz baths)
  • Bedside incision & drainage may be performed for symptomatic relief of severe pain, but is not definitive.

57

What are nonoperative management options for hemorrhoids?

  • Constipation is the most common problem associated with hemorrhoidal disease; thus, one of the hallmarks for therapy is fiber (recommendation: 25 g and 38 g for women and men, respectively) and 64 ounces of fluid per day.
  • Stool softeners can be added if needed.
  • Sitz baths can be used for in the acute settings - thrombosed hemorrhoid or acute flare-up.
  • Topical nitrates and Ca-channel blockers can help patients with increased sphincter tone.

58

Given a patient with appropriate symptoms and findings, be able to perform office-based rubber band ligation.

If a patient continues to have prolapse, pain, and/or bleeding due to their hemorrhoids, she/he should be considered for operative therapy.

  • The goal is to place 1 to 3 bands at the neck of the hemorrhoid.
  • Bands should be at least 1 to 2 cm above the dentate line.
  • There can be a show of blood at 5–7 days after procedure.
  • Complications: rectal bleeding, thrombosis, abscess, pelvic sepsis
  • 18–32% of patients require repeat rubber band treatments.