GI- small bowel, colorectal and anus

Question 1

Anatomy and physiology
1) where does nutrient absorption occur
2) where does water absorption occur
3) Duodenum
a-Most common location for ulcers
b- contains ampulla of Vater (duct of wirsung) and duct of santorini
c- which portions are retroperitoneal
d- where is there a transition point in the duodenum
e- where is vascular supply (arteries and where they run)

Answer 1

1) small bowel
2) small and large bowel
3) a- duodenal bulb (1st portion)
b- 2nd portion (Descending)
c- Descending (2nd) and transverse (3rd) portions are retroperitoneal
d- bw 3rd and 4th portions at the acute angle between the aorta (posterior) and SMA (anterior)-> can get SMA compression of duodenum here if angle too acute
4) superior (off gastroduodenal artery) and inferior (off SMA) pancreaticoduodenal arteries. Both have anterior and posterior branches and many commincations

Question 2

Small bowel Anatomy and physiology
1) what is maximum site of all absorption except for B12, bile acids, iron and folate
2) where is B12, bile acids (conjugated and non-conjucated), iron and folate absorbed
3) Jejunum
a- length
b- vascular supply
c- % of water and NaCl absorbed here
4) Ileum
a- length
b-vascular supply

Answer 2

1) jejunum
2) B12 (terminal ileum), bile: non-conjugated in ileum and conjugated in terminal ileum, iron (duodenum) and folate (Terminal ileum)
3) a-100cm, long vasarecta, circular muscle folds
b- SMA
c-95% NaCl and 90% of water
4) 150 cm, short vasa recta, flat
b- SMA

Question 3

Small bowel Anatomy and physiology

1) enzymes contained in intestinal brush border
2) normal size (circumference) of small bowel/transverese colon/cecum
3) branch of SMA that supplies ileum/cecum

Answer 3

1) maltase, sucrase, limit dextrinase, lactase
2) small bowel- 3cm/ transverse colon-6cm/ cecum 9cm
3) ileocolic

Question 4

Small bowel cell types, which cells:

1) secrete mucin
2) have secretory granules and enzymes
3) do amine precursor uptake and decarboxylation (APUD), 5-hydosytryptamine release and are the precursor for carcinoid
4) have alkaline solution
5) are lymphoid tissue, and where are they increased in number
6) are Ag-presenting cells in intestinal wall

Answer 4

1) goblet cells
2) Paneth cells
3) Enterochromaffin cells
4) Brunner’s glands
5) Peyer’s patches, increased in ileum
6) M cells

Question 5

Small bowel Anatomy and physiology

1) where is IgA released
2) what part of intestines has both heme and Fe transporters
3) phases of the migrating motor complex (gut motility)
4) most important hormone in migrating motor complex and what phase does it act on

Answer 5

1) released into gut and in mother’s milk
2) small bowel
3) Phase I- rest; Phase II- acceleration and gallbladder contraction; phase III- peristalsis; Phase IV- deceleration
4) motilin, acts on phase III= peristalsis

Question 6

Bile salts (Acids)

1) what % are reabsorbed
2) what % is active vs passive resorption and what type of bile salts are absorbed with each and where do they occur
3) why do gallstones form after terminal ileum resection

Answer 6

1) 95%
2) 50/50
active- conjugated bile salts in terminal ileum via Na/K-ATPase only
passive- non-conjugated bile salts- 45% in ileum and 5% in colon
3) malabsorption of bile salts

Question 7

Short Gut Syndrome

1) how is dx made
2) sx
3) what nutritional deficits do these patients have
4) What does the Sudan Red stain check for
5) what does the Schilling test check for
6) how much bowel do you need to survive off TPN
7) rx

Answer 7

1) on symptoms, not gut length
2) diarrhea, steatorrhea (sudan red stain), weight loss, nutritional deficiency
3) lose fat, B12, electrolytes, water
4) looks for fecal fat
5) checks for B12 absorption (radiolabled B12 in urine)
6) 75cm or 50cm with competent ileocecal valve
7) restrict fat, PPI to reduce acid, Lomotil (diphenoxylate and atropine)

Question 8

Causes of steatorrhea

1) mechanism if gastric hypersecretion of acid is the cause
2) mechanism if interruption of bile salt resorption (ie- TI resection) is the cause
3) rx

Answer 8

1) decreased pH-> inc intestinal motility-> interferes with fat absorption
2) interferes with micelle formation and fat absorption
3) control diarrhea (Lomotil), dec oral intake, especially fats, pancrease and PPI

Question 9

Non healing EC fistula

1) causes that interfere with healing
2) what type of fistulas are more likely with proximal bowel (high-or low output) and less likely to close with conservative management
3) what location of fistulas are more likely to close
4) in pt with ECF and persistent fever what should you check for
5) rx

Answer 9

1) FRIENDS: foreign body, radiation, IBD, epithelialization, Neoplasm, Distal obstruction, Sepsis/infection
2) high-output are more likely proximal and less likely to heal
3) colonic fistulas
4) r/o abscess- fistulogram, CT abd, upper GI with small bowel followthrough
5) NPO, TNP, skin protection (stoma appliance), octreotide. If need surgery-> resect segment containing fistula and perform primary anastomosis

Question 10

Bowel Obstruction and most common causes:
1) without previous surgery
a- small bowel
b- large bowel
2) with previous surgery
a- small bowel
b- large bowel
3) why is aggressive fluid resuscitation important in SBP
4) cause of air with bowel obstruction
5) what % are cured with conservative management
6) indications for surgery

Answer 10

1) a- hernia; b-cancer
2) a-adhesions, b-cancer
3) 3rd spacing of fluid into bowel lumen occurs
4) swallowed nitrogen
5) 80% of pSBO and 40% of complete SBO
6) progressing pain, peritoneal signs, fever, increasing WBCs (all signs of strangulation or perforation), or failure to resolve

Question 11

Gallstone Ileus

1) cause
2) Radiologic findings
3) rx

Answer 11

1) fistula bw gallbladder and 2nd portion of duodenum-> SBO from stone in terminal ileum
2) air in biliary tree in pt with SBO
3) remove stone from TI. can leave GB and fistula if pt too sick. if not too sick-> cholecystectomy and close duodenum

Question 12

Meckles diverticulum

1) rule of 2’s
2) embryologic cause
3) MC presentation in kids and adults
4) MC tissue found in meckel’s
5) type of tissue most likely to be symptomatic in meckels and symptoms
6) rx of incidental meckel’s
7) rx of meckels with uncomplicated diverticulitis or bleeding
8) Dx

Answer 12

1) located 2ft from ileocecal valve; 2% of population have it; usually presents in the 1st 2 years of life with bleeding; a true diverticulum
2) failure of closure of the omphalomesenteric duct
3) accounts for 50% of all painless lower GI bleeds in children bleeding
6) don’t remove unless gastric mucosa suspected (feels thick or has very narrow neck)
7) diverticulectomy if uncomplicated. need segmental rsxn if complicated (ie-perf), neck >1/3 of diameter of normal bowel lumen or diverticulitis involves the base
8) Meckel’s scan (99Tc) if trouble localizing (mucosa lights up)

Question 13

Duodenal diverticula

1) what disease process must be r/o
2) rx
3) frequency of diverticula in the 3 diff segments of small bowel

Answer 13

1) r/o gallbladder-duodenal fistula
2) observe unless perf’d, bleeding or causing obstruction or highly symptomatic then do segmental resection. if juxta-ampullary usually need choledochojejunostomy for biliary or ERCP with stent for pancreatitis symptoms (avoid whipple)
3) duodenum> jejunum>ileum

Question 14

Crohn’s Disease

1) age at 1st presentation, ethnicity with increased frequency
2) extraintestinal manifestations
3) what part of GI tract is usually spared
4) MC area involved
5) what % first present with anal/perianal dz and MC sx and rx
6) MC sites for initial presentation

Answer 14

1) 15-35 yo, inc in ashkenazi Jews
2) arthritis, arthralgias, pyoderma gangrenosum, erythema nodosum, ocular diseases, growth failure, megaloblastic enemia from folate and vit B12 malabsorption
3) rectum
4) Terminal ileum
5) 5%, rx- flagyl. large skin tag MC for anal dz.
6) TI and cecum (40%)> Colon only (35%)> small bowel only (20%) >perianal (5%)

Question 15

Crohn’s Disease

1) dx
2) Medical Rx
3) what % eventually need an operation

Answer 15

1) colonoscopy with path showing transmural involvement, segmental dz (skip lesions), cobblestoning, narrow deep ulcers, creeping fat, fistulas and granulomas
2) 5-ASA and loperamide for maintenance. Steroids for acute flares.
Remicaide (infliximab; TNF-alpha inhibitor)- for fistulas or steroid resistant disease. NO agents affect the natural course of disease. TPN may induce remission and fistula closure with small bowel dz
3) 90%

Question 16

Crohn’s Disease

1) Surgical indications
2) rx of pts with diffuse disease of colon
3) Can you do pouches or ilio-anal anastomosis with Crohn’s disease
4) rx of incidental finding of IBD in pt with presumed appendicitis and nl appendix.

Answer 16

1) obstruction that doesn’t resolve with conservative management, abscess (perc drain), Megacolon, hemorrhage (unusual), blind-loop obstruction, Fissures (no lateral internal sphincteroplasty), perineal fistula- unroof and r/o abscess, anorectovaginal fistula- may need rectal advancement flap, pos colostomy. Just get 2cm away from gross dz, no need for clear margins
2) proctocolectomy and ileostomy
3) no
4) remove appendix to avoid future confusion

Question 17

Crohn’s disease

1) when to consider sticturoplasty
2) recurrence rate requiring surgery for Crohn’s disease after resection
3) Complications from removal of Terminal Ileum
4) Colon CA risk of Crohn’s pancolitis compared to risk from UC

Answer 17

1) if pt has mult bowel strictures and need to save length. Not good for 1st surgery. Has 10% leak/abscess/fistula rate.
2) 50%
3) megaloblastic anemia (dec B12 uptake)
osmotic diarrhea and steatorrhea from dec bile salt uptake
Ca oxalate kidney stones 2/2 dec oxalate binding to Ca bc of intraluminal fat binding Ca instead-> inc oxalate absorbed-> released in urine-> hyperoxaluria
Gallstones from malabsorption of bile salts
4) same risk

Question 18

Carcinoid Tumors
1) hormones released by what cells and how to measure
2) MC site
3) pts with tumors where are at inc risk for multiple primaries and second unrelated malignancies
4) Carcinoid rx if:
a- in appendix
b- anywhere else in GI tract
c- unresectable
5) Causes of false 5-HIAA

Answer 18

1) serotonin (produced by Kulchitsky cells (enterochromaffin cells)). Breakdown product is 5-HIAA which can be measured in the urine. Bradykinin also released
2) appendix (50%), then ileum and rectum
3) small bowel tumors
4) a- if appendectomy; if >2cm or involving base=>right hemicolectomy
b-treat like CA (segmental rsxn with lymphadenectomy)
c- chemo: streptozocin and 5FU, usually just for resectable disease
5) fruits

Question 19

Carcinoid syndrome

1) where is the tumor if having this syndorme?
2) sx and the responsible hormones
3) best test for localizing tumor not seen on CT
4) serum test that is highest sensitivity for detecting carcinoid tumor
5) treatment

Answer 19

1) bulky liver mets
2) Kallikrein-> flushing; serotonin-> diarrhea; bradykinin-> asthma-type symptoms
3) Octreotide scan
4) Chromogranin A level
5) if resect liver mets, also resect GB in case of future embolization
octreotide-> for carcinoid syndrome palliation.
Aprotinin for bronchospasm
Phenothiazine (alpha-blockers) for flushing

Question 20

Intussusception in adults

1) causes
2) MC presentation
3) rx

Answer 20

1) small bowel or cecal tumors (worrisome in adults bc often malignant lead point)
2) obstruction
3) resection

Question 21

Benign Small Bowel tumors
1) Adenomas
a- MC location; b- sx; c- rx
2) Puetz-Jeghers Syndrome
a- inheritance pattern
b- associated benign tumors
c- associated malignancies

Answer 21

1) a- duodenum; b- bleeding/obstruction; c-rsxn often with endoscopy
2) a- autosomal dominant
b- small and large bowel hamartomasl pts also have mucocutaneous melanotic skin pegmentation
c- extraintestinal malignancies (MC- breast CA) and small risk of GI malignancies but don’t do prophylactic colectomy.

Question 22

Malignant small bowel tumors
1) MC malignant SB tumor
2) Duodenal CA risk factors
3) Adenocarcinoma
a- how common
b- MC location within SB
c- sx
d- rx

Answer 22

1) adenocarcinoma (but rare overall)
2) FAP, Gardner’s polyps, adenomas, von Recklinghausen’s
3) a- rare
b- duodenal
c- obstruction, jaundice
d- resection and adenectomy. Whipple if in 2nd portion of duodenum

Question 23

Small bowel Leiomyosarcoma

1) MC location
2) how to differentiate with leiomyoma
3) how to differentiate from GIST
4) rx

Answer 23

1) jejunum and ileum; most extraluminal
2) hard. >5mitoses/hpf, atypia, necrosis
3) test for c-KIT (GIST if positive)
4) resection. No adenectomy required

Question 24

Small bowel lymphoma

1) MC location
2) associated diseases
3) MC type of lymphoma
4) Dx
5) Rx if a- in 1st or 2nd portion of duodenum; b- if anywhere else
6) prognosis

Answer 24

1) ileum
2) Wegener’s SLE, AIDS, Crohn’s, celiac sprue
3) NHL B cell type
4) abdominal CT, node sampling
5) a- Chemo-XRT, NO whipple; b- wide en bloc resection including nodes
6) 40% 5-year survival rate

Question 25

Stomas 1) what type of stoma has highest incidence of parastomal hernia? rx? 2) MC stomal infection 3) Diversion Colitis- what is it/cause. Rx 4) MCC of stenosis of stoma. rx 5) MCC of fistula near stoma 6) what type of stoma increases incidence of gallstones and uric acid kidney stones

Answer 25

1) colostomies. no repair unless symptomatic 2) candida 3) hartmann's pouch colitis 2/2 lack of short-chain fatty acids. rx- short-chain fatty acid enemas 4) Ischemia. Rx- dilation if mild 5) crohn's 6) ileostomy

Question 26

Appendicitis 1) order of symptoms 2) MC age 3) CT scan findings 4) what is MC perforation site 5) MCC in children 6) MCC in adults 7) chain of events for appendicitis leading to rupture 8) signs in children 9) signs in elderly

Answer 26

1) 1st-anorexia, 2nd-abdominal pain, 3rd-vomiting. Pain migrates to RLQ as peritonitis sets in 2) 20-35yo 3) diameter >7mm or wall thickness >2mm (looks like bulls eye), fat stranding, no contrast in appendiceal lumen 4) midpoint of antimesenteric border 5) hyperplasia, can follow a viral illness 6) fecalith 7) luminal obstruction-> appendix distension-> venous congestion and thrombosis-> ischemia-> gangrene necrosis and finally rupture (MC in children and elderly 2/2 delayed dx 8) high fever and more Vomiting/diarrhea. Infrequent in infants 9) minimal sx. may need right hemicolectomy if suspect CA

Question 27

Treatment of appendicitis 1) nonoperative situation and CT shows walled off perforated appendix in elderly 2) if during pregnancy a- when is most likely to occur b- what trimester is it the MCC of acute abdominal pain c- what trimester is it most likely to perforate d- where to make incision

Answer 27

1) perc drainage and interval appendectomy at later date once sx improve 2) a- 2nd trimester b-1st trimester c- 3rd trimester (confused with contractions), 35% fetal mortality with rupture d- where pt is having pain (may be in RUQ).

Question 28

``` 1) Appendix mucocele a- benign or malig b- rx c- complication of rupture d- MCC of death 2) treatment if operating for presumed appendicitis but find ruptured ovarian cyst, thrombosed ovarian vein or regional enteritis not involving cecum ```

Answer 28

1) a- can be either. concern for malignant mucous papillary tumor so needs resection b- open appendectomy so don't spill tumor contents. need R hemi if malignant c- pseudomyxoma peritnoei= spread of tumor implants throughout peritoneum d-SBO from peritoneal tumor spread 2) still do appy to prevent future confounding diagnosis

Question 29

Typhoid Enteritis (Salmonella) 1) who gets it 2) sx 3) rx

Answer 29

1) Children 2) RLQ pain, diarrhea, fever, headaches, maculopapular rash, leukopenia, rare bleeding/perforation 3) bactrim

Question 30

Colon Anatomy and Physiology 1) What does it secrete 2) what does it absorb 3) 4 layers from inside to outside 4) 2 muscle layers and where they are

Answer 30

1) K 2) Na and H20 3) mucosa-> submucosa-> muscularis propria-> serosa 4) muscularis propria is circular layer of muscle muscularis mucosa is small interwoven muscle layer just below mucosa but above the basement membrane

Question 31

Colon Anatomy and Physiology 1) what parts of the colon are retroperitoneal 2) what part of the rectum is covered by peritoneum 3) what are the plicae semilunares 4) what are the Taenia coli and at what point do they become broad and completely encircle the bowel

Answer 31

1) ascending, descending and sigmoid colon 2) anterior upper and middle 1/3 of the rectum 3) transverse bands that form haustra 4) 3 bands that run longitudinally along colon. At rectosigmoid junction become broad and encircle the bowel.

Question 32

Colon Anatomy and Physiology 1) Vascular supply to a- ascending colon and 2/3 of transverse colon b-1/3 transverse colon, sigmoid colon and upper portion of the rectum c- what connects SMA to IMA and runs along the colon margin providing collateral flow d- what is the short direct connection bw SMA and IMA e- where does 80% of the blood flow go to?

Answer 32

1) a- SMA (ileocolic, Right colic and middle colic) b- IMA (left colic, sigmoid branches, superior rectal artery) c- marginal artery d-Arc of Rioban e- mucosa and submucosa

Question 33

Colon Anatomy and Physiology What do the following arteries branch off of? 1) Superior rectal artery 2) middle rectal artery 3) inferior rectal artery 4) where do the superior and middle rectal veins drain 5) where does the inferior rectal vein drain 6) where do the superior and middle rectum drain for lymphatics 7) where does the lower rectum drain for lympthatics

Answer 33

1) branch of IMA 2) branch of internal iliac (lateral stalks during low anterior resection [LAR] or abdominoperineal resection [APR] contain the middle rectal arteries) 3) branch of internal pudendal which is branch of internal iliac 4) IMV and eventually portal vein 5) internal iliac vein and into the caval system 6) to IMA nodal lymphatics 7) primarily to IMA nodes but also to internal ileac nodes

Question 34

Colon Anatomy and Physiology 1) where are bowel wall lymphatics 2) what are the watershed areas of the bowel

Answer 34

1) mucosal and submucosal lymphatics 2) a-splenic flexure (Griffith's point) is IMA and SMA junction b- Rectum (Sudak's point)- jnc of superior rectal and middle rectal arteries *colon more sensitive to ischemia than small bowel 2/2 decreased collaterals

Question 35

Internal and External Sphincter 1) which is under voluntary control/CNS control? 2) which is involuntary? 3) external sphincter: a- what nerve controls; b- what muscle is it a continuation of and type of muscle 4) internal sphincter- a- what is the resting state; b- what muscle is it a continuation of

Answer 35

1) external sphincter 2) internal sphincter 3) a-Inferior rectal branch of the internal pudendal nerve; b-continuation of levator ani (striated) muscle 4) a- contracted; b-muscularis propria (smooth muscle)

Question 36

Colorectal Anatomy and Physiology 1) what are the inner and outer nerve plexuses 2) what provides parasympathetic control? 3) what nerves give sympathetic control 4) what muscle marks the transition between the anal canal and rectum 5) distance from anal verge of a- anal canal b-retum c- rectosigmoid junction

Answer 36

1) Meissner's plexus= inner nerve plexus; Auerbach's plexus= outer nerve plexus 2) Pelvic splanchnic nerves 3) lumbar and sacral plexus 4) levator ani 5) a- 0-5cm; b-rectum is 5-15cm; c-rectosigmoid jnc is at 15-18cm

Question 37

Colorectal Anatomy and Physiology 1) what is the main nutrient of colonocytes 2) what are crypts of lieberkuhn 3) colonic inertia- what is it and how to rx 4) pouchitis- how to treat a- stump pouchitis b-infectious pouchitis 5) Denonvilliers fascia (anterior)- where is it 6) Waldeyer's fascia (posterior)- where is it

Answer 37

1) short-chain fatty acids 2) mucus-secreting goblet cells 3) slow transit time. May need subtotal colectomy 4) a- diversion or disuse proctitis-> short chain fatty acid enemas b- rx- metronidazole 5) rectovesicular fascia in men, rectovaginal fascia in women 6) rectosacral fascia

Question 38

Polyps 1) MC type of polyp and risk of CA 2) MC intestinal neoplastic polyp and shape 3) most likley to produce symptoms and risk of CA 4) which ones have inc CA risk 5) which side are they MC found on 6) rx of pedunculated polyp 7) rx of sessile polyp

Answer 38

1) hyperplastic polyp, no CA risk 2) Tubular adenoma- usually pedunculated (75% of polyps) 3) villous adenoma- usually sessile and larger, 50% have cancer 4) >2cm, sessile or villous lesions 5) left-side predominance 6) endoscopic removal 7) segmental resection if can't remove endoscopically

Question 39

Polyps 1) diff bw high-grade dysplasia and intramucosal CA and invasive CA 2) age to start colon CA screening 3) options for colon CA screening and frequency 4) alternatives for colon CA screening 5) things that cause false-positive hemoccult 6) contraindications to colonoscopy

Answer 39

1) high-grade dysplasia and intramucosal CA= basement membrane intact (Carcinoma in-situ) invasive CA (into submucosa=T1) 2) start at 50 for normal risk, at 40 or 10yr before youngest case for intermediate risk (fam h/o colon CA) 3) colonoscopy q10 years or high sensitivity fecal occult blood test q3yr + flex sigmoidoscopy q5 years or high-sensitivity fecal occult blood testing annually 4) CT colonography or double contrast barium enema q 5 years 5) beef, vitamin C, iron, cimetidine 6) recent MI, splenomegaly, pregnancy (if fluoroscopy planned)

Question 40

Treatment of polyps if 1) polypectomy shows T1 lesion 2) extensive low rectal villous adenomas with atypia 3) Path shows T1 lesion after transanal excision of rectal polyp 4) path shows T2 lesion after transanal excision of rectal polyp

Answer 40

1) polypectomy sufficient if margins >2mm and well differentiated with no vascular/lymphatic invasion. Otherwise need formal colon resection 2) transanal excision (can try mucosectomy) of as much of the polyp as possible. NO APR unless cancer present 3) sufficient if margins >2mm, well diff and no vasc/lymph invasion 4) APR or LAR

Question 41

Colorectal CA 1) where does it fall in the leading causes of CA death 2) role of red meat and fat 3) associated infection 4) main gene mutations 5) MC site of primary

Answer 41

1) 2nd MC cause 2) O2 radicals-> tissue damage 3) Clostridium septicum infection 4) APC, DCC, p53, k-ras 5) sigmoid colon

Question 42

Colorectal CA 1) where does it spread 1st 2) most imp prognostic factor 3) MC site of mets (#1 and #2) and what veins they spread via 4) rx of isolated lung or liver mets or direct spread into adj organs 5) prognosis for liver and lung mets 6) what percent get drop metastases to ovaries? 7) Do colon or rectal CA go to bone? if so how?

Answer 42

1) lymph nodes 2) nodal status 3) #1 Liver via portal vein, #2 Lung via iliac vein 4, 5) liver- resect if adequate liver fnc after-> 35% 5yr survival lung-> resect in selected pts-> 25% 5-YS adj spread-> resect en block with portion of adjacent organ 6) 5% 7) Colon CA doesn't go to Bone. Rectal CA can metastasize via Batson's plexus (venous)

Question 43

``` Colorectal CA: 1) better or worse prognosis: a-Lymphocytic penetration b-mucoepidermoid 2) how to stage rectal CA 3) how to r/o synchronous lesions ```

Answer 43

1) a-better Prognosis b- worse prognosis 2) rectal US-good at assessing depth of invasion, sphincter involvement, presence of enlarged nodes or recurrance or MRI 3) total colonoscopy

Question 44

Colorectal CA goals of resection 1) general goals/margins 2) MC surgery of right-sided colon CA 3) surgery for pt with rectal pain with rectal CA

Answer 44

1) en block resection, adequate margins (>2cm), regional adenectomy 2) primary anastamosis without ostomy 3) need APR: Permanent colostomy, anal canal is excised along with rectum. Use when you can't get 2-cm margin for LAR (<2cm from levator ani muscles)

Question 45

Colorectal CA 1) best method of picking up intrahepatic mets? 2) resolution of conventional U/S vs. Abd CT vs. MRI vs. Intraop US

Answer 45

1) intraoperative US 2) Conventional US res is 10mm Abdominal CT is 5-10mm Abdominal MRI is 5-10mm (better than CT) Intraop US is 3-5mm

Question 46

Abdominoperineal Resection (APR) 1) what is excised and type of ostomy 2) risks 3) when to use in colorectal CA 4) risk of local recurrence of rectal vs colon CA

Answer 46

1) rectum and anal canal, permanent colostomy 2) impotence and bladder dysfunction (injured pudendal nerves) 3) malignant lesions only (not benign tumors) that are not amenable to APR, ie- don't have at least 2-cm margin (2cm from levator ani muscles) with LAR 4) higher with rectal CA than colon CA in general

Question 47

Colorectal CA 1) role of preop chemo-XRT 2) T1-4 staging 3) N1-3 staging 4) Describe the stages of colorectal CA

Answer 47

1) produces complete response in some pts with rectal CA, preserves sphincter function in some 2) T1 into submucosa, T2 into muscularis propria, T3 into serosa or through muscularis propria; T4 through serosa into free peritoneal cavity or adj organs/structures 3) N0=no nodes; N1=1-3 positive nodes; N2 4+ positive nodes; N3= central nodes positive 4) 0=Tis; I=T1-2, II= T3-4. III=N+, any T; IV=M1

Question 48

Rectal CA 1) which rectal CA can be excised transanally 2) which rectal CA need APR or LAR

Answer 48

1) low rectal T1 (limited to submucosa) if t meet criteria above

Question 49

Chemo in colorectal CA 1) when is postop chemo, no XRT indicated 2) when is preop chemo-XRT indicated 3) treatment for Stage IV rectal CA 4) what chemo agents are used

Answer 49

1) Stage III and IV (nodes positive or distant mets) 2) Stage II or III 3) chemo and XRT +/- surgery 4) 5FU, leucovorin, and oxaliplatin (FOLFOX)

Question 50

XRT in colorectal surgery 1) benefits 2) damage/risks

Answer 50

1) decreased local recurrence and increased survival when combined with chemo. May down-stage tumor possibly allowing LAR instead of APR 2) rectum MC injured- vasculitis, thrombosis, ulcers, strictures

Question 51

Colorectal CA 1) when is recurrence MC 2) Followup required

Answer 51

1) MC within 1 year. 20% overall recurrence, 5% get another primary 2) get f/u colonoscopy at 1 year to check for new primaries (Metachronous)

Question 52

Familial Adenomatous Polyposis (FAP) 1) inheritance pater 2) Cancer incidence 3) Gene responsible 4) screening 5) Surgical treatment 6) MCC of death after surgery

Answer 52

1) Autosomal Dominant, 20% are spontaneous 2) 100% by age 40 3) APC gene, chromosome 5 4) don't need colonoscopy. polyps aren't present at birth, but are present in puberty. just do screening sigmoidoscopy. Also get duodenal polyps- get endoscopy q2 years to check. After surgery, need lifetime surveillance of residual rectal mucosa 5) all need total colectomy prophylactically at age 20- do proctocolectomy, rectal mucosectomy and ileoanal pouch (J-pouch). 6) periampullary tumors of the duodenum

Question 53

1) Gardner's syndrome- associated gene and cancers | 2) Turcot's syndrome- associated gene and cancers

Answer 53

1) APC gene. Colon CA, desmoid tumors, osteomas | 2) APC gene. colon CA and brain CA

Question 54

Lynch Syndromes (Hereditary Nonpolyposis colon CA 1) inheritance and what % of population has it 2) associated mutation 3) Prediliction for what type of CA overall a-in Lynch I b- in Lynch II 4) what is the amsterdam criteria for Lynch syndrome 5) surveillance 6) Treatment

Answer 54

1) autosomal dominant, 5% of the population have 2) DNA mismatch repair gene 3) right-sided and multiple colon CA a- just colon CA risk b- colon CA + ovarian, endometrial, bladder and stomach CA 4) 3-2-1-> at least 3 first degree primary relatives, over 2 generations, 1 with cancer before age 50 5) screening colonoscopy starting at age 25 or 10yr before primary relative got CA + surveillance for the other CA types in the family 6) 50% get metachronous lesions within 10yrs and often have multiple primaries-> need total proctocolectomy with first CA operation

Question 55

``` Sigmoid volvulus 1) what type of diet predisposes to it 2) who is at higher risk? 3) AXR findings 4) Gastrografin enema findings 5) rx if a- not gangrenous or peritoneal signs b- gangrenous or peritoneal signs ```

Answer 55

1) high-fiber ( Iran, Iraq) 2) debilitated psychiatric pts, neuro dysfnc, laxative abuse 3) bent inner tube sign 4) bird's beak sign (tapered colon 5) a- decompress with colonoscopy (80% reduce, 50% recur). Give bowel prep and perform sigmoid colectomy during same admission b- no decompression-> go straight to OR for signoidectomy

Question 56

Cecal Volvulus 1) age in which it occurs 2) XR appearance 3) rx

Answer 56

1) 20s-30s 2) can appear as SBO with dilated cecum in RLQ 3) OR-> right hemicolectomy (decompression unlikely to succeed). If pt is frail and colon is viable can try cecopexy

Question 57

Ulcerative Colitis 1) Symtoms 2) layers of bowel involved 3) what part of GI tract is spared? and pattern of bowel affected? 4) colonoscopy findings 5) Barium enema findings 6) Medical rx

Answer 57

1) bloody diarrhea, abd pain, fever, weight loss 2) mucosa and submucosa 3) spares anus. starts distally in rectum and is contiguous. 4) bleeding is universal, mucosal friability with pseudopolyps, crypt abscesses and collar button ulcers. bx and r/o infectious cause. backwash ileitis can occur with proximal disease. 5) with chronic disease see loss of haustra, narrow caliber, short colon and loss of redundancy 6) sulfasalazine (or 5-ASA) and loperamide for maintenance therapy= maintain remission. Steroids for acute flares. Consider cyclosporine or infliximab for steroid-resistant disease

Question 58

Ulcerative Colitis and Toxic Colitis or Toxic Megacolon 1) definition of Toxic Colitis 2) definition of Toxic megacolon 3) initial treatment and what should you avoid in these patients 4) absolute indications for surgery

Answer 58

1) >6 bloody BM/d, fever, inc HR, drop in Hgb, leukocytosis 2) above + distension, abdominal pain and tenderness 3) NGT, IVF, steroids, bowel rest and abx (Cipro/flagyl) will treat 50% adequately. the other 50% require surgery. follow with serial AXR and clinical response to determine. AVOID barium enemas, narcotics, anti-diarrheal agents and anti-cholinergics 4) Pneumoperitoneum, diffuse peritonitis or localized peritonitis with increasing pain or colonic distension >10cm, uncontrolled sepsis, major hemorrhage

Question 59

Ulcerative Colitis 1) where is perforation most likely to occur? what about in Crohn's? 2) surgical indications for UC 3) Surgery to do for emergent/urgent resections 4) surgery for elective resections 5) MC complication of elective ileoanal anastomosis in UC 6) reasons that the ileoanal anastomoses may need resection at a later time 7) rx of infectious pouchitis

Answer 59

1) transverse colon in UC, distal ileum in Crohns 2) massive hemorrhage, refractory toxic megacolon, acute fulminant UC (in 15%), obstruction, any dysplasia, cancer, intractability, systemic complications, failure to thrive and long standing disease (>10yr) as prophylaxis against colon CA (somewhat controversial) 3) total proctocolectomy and bring up ileostomy, perform definitive hook-up later 4) ileoanal anastamosis (rectal mucosectomy, J-pouch, and ileoanal/low-rectal anastamosis). For this need lifetime surveillance of residual rectal area. Need temporary diverting ileostomy (6-8 wk) while pouch heals. Can also do APR with ileostomy. 5) leak- rx with drainage and abx 6) cancer, dysplastic changes, refractory pouchitis, or pouch failure (incontinence) 7) Flagyl

Question 60

Ulcerative colitis 1) Cancer risk in pts with pancolitis and screening 2) Extraintestinal manifestations in UC a- MC one to require total colectomy b- which ones get better with colectomy c- which don't get better with colectomy d- rx of pyoderma gangrenosum e-gene that is responsible for sacroiliitis, ankylosing spondylitis and ulcerative colitis f- T/F: thromboembolic dz is a complication

Answer 60

1) 1% per year starting 10years after initial dx. need yearly colonoscopy starting 8-10 yr after initial diagnosis 2) a- failure to thrive in children b- ocular prbms, arthritis, anemia. c- primary sclerosing cholangitis, ankylosing spondylitis. 50% of pyoderma gangrenosum get better and 50% don't d-steroids e- HLA B27 f-true

Question 61

``` Carcinoid of the colon and rectum 1) what % of carcinoids are here 2) most important predictor of mets 3) what % have local or systemic spread 4) Treatment of a- low rectal carcinoids b- high rectal or colon carcinoids ```

Answer 61

1) 15% 2) size of tumor 3) 2/3 4) a- if wide local excision with negative margins. if >2cm-> APR b- formal resection with adenectomy

Question 62

Colonic obstruction 1) Law of LaPlace 2) where is perforation with obstruction most likely to occur based on Law of LaPlace 3) 2 MCC of colonic obstruction 4) what is pneumatosis intestinalis an indicator of 5) what about air in the portal system

Answer 62

1) Tension= Pressure x Diameter 2) cecum (smalles diameter) 3) #1 Cancer, #2 diverticulitis 4) bowel wall ischemia-> dissection of air through areas of bowel wall 5) significant infection or necrosis of the large or small bowel. V. ominous sign

Question 63

Olgalvie's syndrome 1) what is it 2) risk factors 3) medical/conservative treatment 4) indications of high risk for bowel perf and options for treatment

Answer 63

1) pseudoobstruction of colon-> massively dilated colon which can perforate 2) opiate use, bedridden or older pts, recent surgery, infection or trauma 3) check and replace electrolytes, especially K. discontinue drugs that slow the gut (ie- narcotics), NGT 4) if colon >10cm-> decompression with colonoscopy and neostigmine, cecostomy if that fails

Question 64

Amoebic Colitis 1) what bug? and how do you get it 2) where does primary infection occur 3) secondary infection 4) risk factors 5) symptoms 6) Dx 7) rx

Answer 64

1) Entamoeba histolytica, from contaminated food and water with feces that contain cysts 2) primary in colon; 3) secondary in liver 4) travel to Mexico, ETOH, fecal-oral transmission 5) similar to Ulcerative Colitis (dysentery)l chronic more common form (3-4BM/d, cramping, fever 6) endoscopy-> ulceration, trophozoites; 90% have anti-amebic Ab 7) flagyl, diiodohydroxyquin

Question 65

Actinomyces 1) symptoms 2) MC location 3) pathology 4) rx

Answer 65

1) can present as a mass, abscess, fistula or induration. Suppurative and granulomatous. 2) Cecum MC location. (can be confused with CA) 3) yellow-white sulfur granules 4) penicilin or tetracycline. drain any abscess

Question 66

Diverticula 1) what is it 2) cause 3) MC location: a- overall, b- if bleeding, c- if diverticulitis occurs

Answer 66

1) herniation of mucosa through colon wall at sites where arteries enter the muscular wall (false diverticula), circular muscle thickens adjacent to diverticulum with luminal narrowing 2) straining (inc intraluminal pressure) 3) a- left side; b- right side (50% of bleeds from right); c-left side

Question 67

Lower GI bleed 1) how long after bleed can stool guaiac stay positive 2) location of bleeding if hematemesis 3) cause of azotemia after GI bleed 4) amount of bleeding needed to detect with a- arteriography b-tagged RBC scan

Answer 67

1) 3 weeks 2) from pharynx to ligament of Treitz 3) production of urea from bacterial action on intraluminal blood (inc BUN; also get elevated total bili) 4) a-0.5+ cc/min; b-0.1+ cc/min

Question 68

Diverticulitis 1) cause 2) Dx 3) why do you need follow-up colonoscopy after an episode of diverticulitis? 4) MC complication and rx 5) rx of uncomplicated diverticulitis 6) indications for surgery, and what surgery to do

Answer 68

1) mucosal perforation in the diverticulum with adjacent fecal contamination- denotes infection and inflammation of the colonic wall as well as surrounding tissue 2) CT scan needed only if worried about complications of disease 3) to r/o colorectal CA 4) abscess formation-> perc drain 5) levofloxacin and flagyl, bowel rest for 3-4 days (mild cases can be treated as an outpatient) 6) for significant complications (total obstruction, perforation or undrainable abscess or inability to exclude CA)- resect all of sigmoid colon down to superior rectum (distal margin is nl rectum)

Question 69

DIverticulitis 1) rx of right sided diverticulitis discovered at time of incision for appendectomy 2) dx and rx of colovesicular fistula

Answer 69

1) do R hemicolectomy. (80% of R-sided diverticulitis discovered incidentally this way) 2) sx- fecauluria, pneumouria in men>women (women get colovaginal fistula more often) dx- cystoscopy rx- close bladder opening, resect involved segment of colon and perform reanastomosis, diverting ileostomy. Interpose omentum bw bladder and colon

Question 70

Diverticulosis bleeding 1) T/F: MCC of lower GI bleed 2) cause 3) dx 4) rx and when to go to OR 5) rx for recurrent diverticular bleeds

Answer 70

1) true (after upper GI bleed of course) 2) disrupted vasa rectum-> arterial bleeding 3) NGT to r/o upper GI source. then colonoscopy-> can try hemo-clips and localize bleeding Angio 1st if massive bleed (hypotension/tachy)- can try to embolize or at least localize for surgery tagged RBC scan for hard to localize bleeds 4) Go to OR if hypotensive and not responding to resuscitation-> colectomy at site of bleeding if identified or subtotal colectomy if source not localized 5) resect the area.

Question 71

Angiodysplasia bleeding 1) what side of colon most affected 2) type of bleeding 3) signs of angiodysplasia on angiogram 4) what is associated cardiac abnormality

Answer 71

1) right side 2) venous bleeding (less severe, more likely to recur) 3) - tufts, slow emptying 4) aortic stenosis in 20%- gets better after valve replacement

Question 72

Ischemic colitis 1) causes 2) most vulnerable areas to low-flow state Dx and rx

Answer 72

1) low-flow state (recent MI, CHF), ligation of IMA at surgery (ie- AAA repair), embolus or thrombosis of the IMA, sepsis 2) watershed areas: Splenic flexure (Griffith's pt= SMA and IMA jnc); upper rectum (Sudeck's pt= superior and middle rectal artery jnc) 3) CT scan or endoscopy. - lower 2/3 of rectum spared (supplied by middle and inferior rectal arteries off the internal iliacs - if gangrenous colitis suspected (peritonitis): no colonoscopy and go to OR-> sigmoid resection or left hemicolectomy

Question 73

Pseudomembranous Colitis (C. diff) 1) risk factors 2) recurrance rate 3) key finding on pathology 4) MC location 5) dx 6) rx

Answer 73

1) abx (up to 3 wks after), postop, elderly, ICU pts 2) 15% 3) PMN inflammation of mucosa and submucosa. Pseudomembranes, plaques, and ring-like lesions 4) distal colon 5) C. diff toxin 6) oral- vanc or flagyl. IV- flagyl. Lactobacillus can also help. Stop other abx or change them

Question 74

Neutropenic typhlitis (enterocolitis) 1) when do ppl get it 2) is pneumatosis intestinalis a surgical indication in these pts 3) rx

Answer 74

1) follows chemo when WBCs are low (nadir) 2) no 3) abx, pts will improve when WBCs increase. surgery only for free perforation

Question 75

Other Colon diseases 1) causes of colitis 2) Yersinia-a- what disease process does it mimic; b- how do you get it; c-rx 3) Megacolon 2/2: a- Hirschsprung's disease- MC area affected and dx b- Trypanosoma cruzi- pathophysiology

Answer 75

1) salmonella, shigella, campylobacter, CMV, Yersinia, GIardia, other viral infections 2) a- appendicitis, b- contaminated food (feces/urine), c- tetracycline or bactrim 3) Enlargement is proximal to non-peristalsing bowel a- rectosigmoid MC. dx- rectal bx b- MC aquired cause. 2/2 destruction of nerves

Question 76

Anal and Reectal anatamoy 1) arterial supply to the anus 2) venous drainage a- above the dentate line, b-below the dentate line

Answer 76

1) inferior rectal artery | 2) a- internal hemorrhoid plexus; b-external hemorrhoid plexus

Question 77

Hemorrhoids 1) Locations of the hemorrhoidal plexi 2) line that differentiated bw internal and external hemorrhoids 3) type of cells for internal vs external 4) rx 5) rx of thrombosed external hemorrhoid

Answer 77

1) left lateral, right anterior and right posterior hemorrhoidal plexus 2) dentate line 3) distal to line (external) has sensate squamous epithelium-> pain, swelling, itching. Superior to dentated line (internal) are covered by mucosa-> no sensation 4) fiber and stool softners (prevent straining), sitz baths 5) lance open if >72 hours or elliptical excision if

Question 78

4 Types of Internal hemorrhoids 1) Primary 2) Secondary 3) Tertiary 4) Quaternary

Answer 78

1) slides below dentate with strain 2) prolapse and reduce spontaneously 3) prolapse and have to be manually reduced 4) not able to reduce

Question 79

Hemorrhoids 1) surgical indications 2) rx of external hemorrhoids 3) rx of primary and secondary internal hemorrhoids 4) rx of tertiary and quartenary internal hemorrhoids 5) post op care

Answer 79

1) recurrence, thrombosis multiple times, large external component 2) resect with elliptical excision 3) band primary and secondary internal hemorrhoids (don't band external hemorrhoids bc too painful) 4) 3 quadrant resection down to internal anal sphincter (but not through it!) 5) sitz baths, stool softener, high-fiber diet

Question 80

Rectal prolapse 1) where does it start 2) pathophysiology 3) risk factors 4) what layers of rectum are involved 5) medical rx 6) surgical rx

Answer 80

1) 6-7cm from anal verge 2) 2/2 pudendal neuropathy and laxity of the anal sphincters 3) female, straining, chronic diarrhea, pervious pregnancy and redundant sigmoid colons 4) all layers 5) high-fiber diet 6) perineal rectosigmoid resection (Altemeier) transanally if pt is older and frail. low anterior resection and pexy of residual colon if pt in good condition

Question 81

1) rx of condulomata cuminata 2) rx of pilonidal cyst 3) anorectal abscess a- which can be drained through the skin (are below the levator muscles) b- which can form horseshoe abscesses c- which need to be drained transrectally

Answer 81

1) laser surgery 2) drainage and packing followed by surgical resection of the cyst 3) a- perianal, intersphincteric and ischiorectal abscesses can be drained through skin (below levator muscles) b- intersphincteric and ischiorectal c- supralevator abscesses need to be drained transrectally

Question 82

Anal Fissure 1) MC location 2) what will you see with chronic fissure 3) rx 4) Most serious complication of surgery 5) when is surgery C/I 6) WHAT should you worry about with lateral or recurrent fissures

Answer 82

1) 90% in posterior midline, caused by split in anoderm 2) can get sentinel pile 3) sitz baths, bulk, lidocaine jelly and stool softeners (90% will heal) surgical rx- lateral subcutaneous internal sphincterotomy 4) fecal incontinence 5) IBD 6) IBD

Question 83

Fistula-in-ano 1) what precurses its formation 2) do you need to excise the tract 3) what is Goodsall's rule 4) rx of fistulas that a- connect to the lower 1/3 of external anal sphincter b- in upper 2/3 of external anal sphincret 5) Most worrisome complication/ reason we don't use fistulotomy for fistulas above the lower 1/3 of external anal sphincter

Answer 83

1) anorectal abscess 2) no 3) anterior fistulas go in straight line toward anus/rectum. posterior fistulas go toward a midline internal opening in anus/rectum 4) a- fistulotomy (open tract up, curettage out, let it heal by secondary intention b- rectal advancement flap: 5) risk of incontinence- want to avoid damage to external anal sphincter

Question 84

Rectovaginal Fistulas 1) simple- where are they located and rx 2) complex- where are they located and rx

Answer 84

1) low to mid-vagina. rx- trans-anal rectal mucosa advancement flap (many obstetrical fistulas heal spontaneously) 2) high vagina, rx- abdominal or combined abdominal and perineal approach. resection and re-anastomosis of rectum, close hole in vagina, interpose omentum, temporary ileostomy

Question 85

Anal Incontinence- 1) rx if 2/2 nerogenic cause. 2) Abdominoperineal descent as cause- pathophysiology and rx 3) rx if 2/2 obstetrical trauma

Answer 85

1) no good rx 2) chronic damage to levator ani muscle and pudendal nerves (obesity, multiparous women) and anus falls below levators. rx- high-fiber diet, limit to 1BM a day. hard to rx 3) anterior anal sphincteroplasty

Question 86

anorectal ulcerations and AIDS in anorectal problems 1) Kaposi's sarcoma- appearance 2) CMV- appearance and presentation. rx? 3) MCC of rectal ulcer 4) B cell lymphoma- presentation 5) MCC of cancer in AIDS pts 6) how to diagnose cause of ulcer in AIDS pts

Answer 86

1) nodule with ulceration 2) shallow ulcers, presents similar to appendicitis. rx- ganciclovir 3) HSV 4) looks like abscess or ulcer 5) Kaposi's sarcoma 6) need bx

Question 87

Anal Cancer 1) associated risk factors 2) what differentiates the anal canal from the anal margin 3) Cancers seen in anal canal 4) cancers seen in anal margin 5) which location has a better prognosis

Answer 87

1) HPV and XRT 2) anal canal is above the dentate line; anal margin is below the dentate line 3) Above the dentate line: Squamous cell CA (epidermoid, mucoepidermoid, cloacogenic, basaloid CA); adenocarcinoma, melanoma (3rd MC site for melanoma) 4) Below the dentate line: squamous cell CA and basal cell CA 5) anal margin (below dentate line)

Question 88

Anal Cancer: Squamous cell CA 1) sx; 2) treatment if in anal canal/above the dentate line; 3) rx if in anal margin/below the dentate line 4) where do anal margin mets go?

Answer 88

1) pruritis, bleeding, palpable mass if above dentate line; below dentate line: ulcerating, slow growing 2) above dentate line: Nigro protocol (Chemo-XRT with 5-FU and mitomycin) not surgery!. APR for treatment failure or recurrence 3) WLE if 5cm, inolving sphincter or if positive nodes. Need inguinal node dissection if clinically positive 4) to inguinal nodes

Question 89

Anal CA: 1) Adenocarcinoma treatment a- MC b- if

Answer 89

1) a- APR is usual b- WLE with 1cm margin *both need postop chemo/XRT same as rectal CA 2) a-#1 skin, #2-eyes, #3-anal b-mesenteric LNs c- hematogenous spread to liver and lungs d- bleeding e- APR usual, margin dictated by depth of lesion, standard for melanoma 3) a- central ulcer, raised edges, rare mets b- WLE usually sufficient with 3mm margins. APR only needed if sphincter involved

Question 90

Nodal Mets: 1st site of spread for 1) superior and middle rectum 2) lower rectum 3) upper 2/3 of anal canal 4) lower 1/3 of anal canal

Answer 90

1) IMA nodes 2) primarily IMA nodes, also to internal iliac nodes 3) internal iliac nodes 4) inguinal nodes