Lower Gastrointestinal Disorders Flashcards Preview

NMS Casebook > Lower Gastrointestinal Disorders > Flashcards

Flashcards in Lower Gastrointestinal Disorders Deck (114)
Loading flashcards...
1
Q

What is an “obstructive series”

A

Upright PA and lateral CXR, and flat and uptright abdominal radiograph

2
Q

Why do patients with SBO typically present with contraction alkalosis and hypokalemia?

A

When patients have SBO they tend to vomit because of bowel back up. This results in loss of H2O, Na+, H+ and Cl- with an overall decrease in plasma volume from H20 loss and an increase in pH due to H+ loss…giving you alkalosis. Hypovolemia and alkalosis causes the kidneys to retain more Na+ and H+…thus giving you hypokalemia.

3
Q

How do you correct a contraction alkalosis in a patient with SBO?

A

IVF containing Na and K usually does the job

4
Q

When is it appropriate to d/c a patient w/SBO

A

Pain and distention resolution w/toleration of food after NG removal.

5
Q

Differential diagnosis for SBO in a patient with no prior abdominal surgeries?

A

Adhesions can still form regardless of surgical history. Hernia, bowel tumors or inflammatory processes can also cause SBO.

6
Q

A patient presents with nausea, vomiting, abdominal distention and tenderness to palpation of the abdomen. She says that she has had symptoms for the past 2 days and only has passed small amounts of diarrhea. What do you need to do in your assessment of this patient?

A

Typically complete SBO presents with no BMs. Small amounts of diarrhea can indicate constipation and you need to check for fecal impaction. Gastroenteritis and partial SBO should also be in your differential.

7
Q

What is the most common tumor metastasis in the intestine?

A

Melanoma, it frequently manifests as SBO that does not resolve with nonoperative management. Even if the tumor is not resectable, surgical measures should be taken to relieve the obstruction.

8
Q

A patient presents with SBO and a PHMx significant for ovarian cancer. What is at the top of your differential?

A

Recurrent ovarian cancer can happen locally or as peritoneal studding, resulting in obstruction.

9
Q

How can breast cancer affect the bowel?

A

Breast cancer mets can manifest as SBO

10
Q

What is a good physical exam finding that tells you this patient needs surgical exploration for SBO?

A

Localized tenderness, markedly elevated temperature, localized pain around hernia, free air under diaphragm on CXR and marked leukocytosis can indicate closed loop obstruction, perforation, ischemia or abscess. Metabolic acidosis is suspicious for ischemia or necrotic bowel and depending on the patients status and imaging mertis either urgent surgical exploraiton or mesenteric arteriography before exploration to check for arterial occlusion.

11
Q

Post-op plan for pt that underwent LOA to correct SBO

A

NPO w/NG tube until bowel function returns. Once patient tolerates food d/c.

12
Q

What is a second look operation in regards to surgery for SBO?

A

If the SBO was due to a closed loop obstruction and it was questionable if the bowel would still be viable, you re-explore the abdomen in 24 hours to assess for viability and resect any ischemic or necrotic bowel followed by anastamosis. Don’t just send the patient home because ischemic bowel will present several days later and make the patient much sicker.

13
Q

Management of a patient with SBO due to hernia.

A

Exploration through hernia incision if patient is stable. Exploration through midline abdominal incision if patient appears ill to more thoroughly inspect the entire bowel for ischemia and necrosis. Repair the hernia and resect non-viable bowel.

14
Q

Management of accidental enterotomy during intra-abdominal procedure

A

If small, primary repair is fine. If large, resection and anastomosis are required. Either way, the patient will be at risk for small bowel fistulas and leaks post-op.

15
Q

A patient presents with heart failure, COPD and urinary sepsis. The sepsis is resolved in the hospital, but he has SBO now. After NG drainage and NPO treatment, the patient still cannot tolerate solids. You are unsure if the obstruction is mechanical or from paralytic ileus due to his many comorbidities. How do you determine if you need to do surgery or not?

A

Upper GI series w/small bowel follow through. Note that constipation can be seen on radiographs and in upper GI series the Barium will still find its way through the impacted stool.

16
Q

Work up of a patient with possible mesenteric ischemia

A

Pain out of proportion to PE, nonspecific ileus on radiographs, hydrate/oxygenate/perfuse, sigmoidoscopy to check for ischemia, mesenteric angiogram if sigmoidoscopy is negative. If the patient looks really sick and you suspect necrotic bowel you can go straight to the OR.

17
Q

This patient presents with 1 day hx of nausea, vomiting and sever abdominal pain. PE shows abdominal distention and tenderness. Her pain seems much more severe than her abdominal findings. Sigmoidoscopy shows ischemic bowel. Mesenteric angiogram is shown below. How do you tx this patient?

A

Revascularization of SMA due to risk of recurrence, necrosis and a much worse episode. Also put the patient on aspirin.

18
Q

When can you go directly to the OR for a patient with suspected ischemic bowel?

A

Significantly worsening pain over acute time period, markedly elevated WBC/markedly decreased WBC in elderly or metabolic acidosis

19
Q

When is an angiogram an acceptable next step before taking a patient with mesenteric ischemia to the OR?

A

Hx of a-fib, hx of abdominal bruit (looking for stenotic celiac/SMA) and hx of thoracic aortic dissection.

20
Q

A patient presents with symptoms of mesenteric ischemia. His hct is 55%, how do you manage this patient?

A

Most common cause of polycythemia is dehydrate, so rehydrate the patient. If the patient has polycythemia vera the patient needs phlebotomy, rehydration, angiography and surgery if angiography indicates significant occlusion. If the patient has COPD, he needs a pulmonology consult to improve ventilation which will decrease RBC load.

21
Q

A patient presents with sx of mesenteric ischemia and hx of CHF. How do you manage this patient?

A

Ischemia may be due to low flow nonocclusive state, confirmed by angiogram. Tx involves direct mesenteric infusion of papaverine (PED10A inhibitor) to vasodilate and meds to improve cardiac output. If necrosis is likely go to the OR, where you will likely see small punctate areas of necrosis, indicating a low flow state. Post-op hemodynamic optimization and second look is a reasonable approach without immediate resection.

22
Q

Next step in a patient with suspect mesenteric ischemia and bloody diarrhea?

A

Sigmoidoscopy, if full-thickness necrosis is present then send for surgery. If only mucosal necrosis, optimize hemodynamics, give abx and admit for observation.

23
Q

How do you treat a patient with mesenteric necrosis from the ligament of Treitz to the transverse colon?

A

Let the succumb to the disease and die. In younger individuals you may consider surgical resection and reanastaomosis followed by chronic TPN or small bowel transplant due to short bowel syndrome.

24
Q

How do patients present if they develop short bowel syndrome from multiple bowel resections?

A

Deficiencies in vitamins A (night blindness, xerophthalmia, xerosis, Bitot spots and keratinization of the skin and mucous membranes), D (muscle aches, muscle weakness, bone pain, osteomalacia and hypocalcemia), E (mild hemolytic anemia and nonspecific neurologic deficits), K (easy bruisin/bleeding), B9 (macrocytic anemia), and B12 (macrocytic anemia + posterior column deficits), calcium,magnesium, iron, and zinc.

25
Q

Management differences in relatively healthy patients with necrotic bowel resection vs. ill patients with necrotic bowel resection?

A

Healthy: direct anastomoses after resection w/second look if you’re really concerned about the viability of the bowel. Ill: ileostomy for direct visualization of the bowel and no concern for leak.

26
Q

Ulcerative Colitis vs. Crohn’s disease

A
27
Q

How are strictures and fistulas typically managed in patients with Crohn’s disease?

A

Get CT to r/o perforation or abscess. Tx nonop w/TMP, bowel rest and observation. Management is based on patient symptoms and active problems, not radiologic findings. Only if SBO from stricture does not resolve do you consider resection of stricture back to normal bowel and anastomosis or stricturoplasty (axial cut of stricture w/ transverse repair to dilate lumen).

28
Q

What is the problem with resecting a stricture at the terminal ileum in a patient with Crohn’s disease?

A

The terminal ileum reabsorbs B12 and bile acids. B12 deficiency results in megaloblastic anemia posterior column sx. Bile acid deficiency results in diarrhea, malabsorption and oxalate stones.

29
Q

Tx for patient w/perianal abscesses and fistulas?

A

Drain the abscess and open the fistula tract +/- seton if the tract is deeper. Rx metronidazole

30
Q

Tx for Crohn’s colitis

A

Sulfasalazine (5-acetylsalicylic acid compound) if confine to colon. Colectomy +/- ileostomy is often necessary.

31
Q

Risk for developing colorectal cancer in patients with UC? How do you account for this medically?

A

Low for 1st 10 years (2-3%). Increases 1-2% per year after 10 years. Consequently patients should have colonoscopy every 1-2 years 8-10 years after disease onset. Colonscopy should include biopsy of suspicious lesions (strictures, polyps and plaques) and random biopsies because UC colorectal cancer does not always follow the polyp to cancer sequence. Proctocolectomy (removal of mucosa w/ileal pouch and anal anastomosis) is indicated if severe dysplasia is present. Note that these types of surgeries have a high reoperative and failure rate, despite curing the cancer.

32
Q

What is the blood supply to the colon

A
33
Q

What is the blood supply to the rectum?

A
34
Q

What type of surveillance do you need to do in a patient with UC after they have proctocolectomy?

A

If there is no rectal mucosa left, none. If rectal mucosa is left over, proctoscopy every 6-12 months.

35
Q

A woman presents 6 months after proctocolectomy for UC with fever, blood-tinged diarrhea and pain w/defecation. How do you treat her?

A

She has pouchitis. Confirm the dx w/endoscopy looking for hemorrhagic mucosa with edema and small ulceration. Tx with metronidazole.

36
Q

A patient presents to the ER with recurrent bloody diarrhea, abdominal pain and distention. T-101, HR-120, abdomen is distended and acutely tender. PMHx significant for UC. How do you evaluate and treat this patient?

A

PMHx significant for UC w/her sx is concerning for toxic megacolon. You should get CBC and an obstructive series to r/o perf. If toxic megacolon is confirmed, place NG, put pt as NPO, add TPN, IVFs, broad spectrum abx and high dose IV steroids. Then admit for close observation. This resolves 50% of cases. Indications for ileostomy with Hartmann pouch of rectum and total abdominal colectomy include no improvement over 3-6 days, no response to medical management, air in the colon wall (indicating impending perf) or perf (mortality rate of 27-44%).

37
Q

A patient presents to the ED with RLQ pain exaccerbated by pain in the right pelvis on rectal exam. What might this indicate?

A

Possible retrocecal appendicitis, ovarian pathology or PID.

38
Q

Work up for a patient with RLQ pain that could be appendicitis

A

NPO, Hydration, observation w/serial exams and CBC. Pain meds should be avoided so as not to mask sx. You may also order u/s to r/o gyn pathology or CT to dx appendicitis.

39
Q

RLQ pain + hematuria

A

Severe UTI or kidney stone. Dx w/IV pyelogram or CT w/o contrast to check for stones.

40
Q

RLQ pain + dysuria and high WBC

A

UTI or appendicitis. Continue to observe and follow patient.

41
Q

RLQ pain + cervical motion tenderness

A

PID -> gyn consult

42
Q

RLQ pain + adnexal tenderness

A

Appendicitis, PID or TOA

43
Q

Initial tx for IBD

A

5-acetylsalicylic acid-containing compounds + steroids. Make sure to r/o appendicitis before giving steroids because it can obscure the correct dx due to decreased inflammation.

44
Q

Epidemiology of appendicitis

A

Bimodal distribution with peaks at ages 25 and 65. Older adults typically present with non-classic sx of vague abdominal pain, sepsis, altered mentation and failure to thrive. Little kids more often present with ruptured appendix.

45
Q

Where does appendicits present in pregnant women? How is it managed?

A

Presents in upper and lateral abdomen due to uterine enlargement. Appenectomy is safe during pregnancy and should be done to minimize risk of peritonitis.

46
Q

A patient presents with appendicitis and you take her to the OR. In the OR the appendix is red with an inflamed appendiceal tip w/exudate. How do you treat this?

A

Ligate the appendix at its base and cauterize the stump.

47
Q

A patient presents with appendicitis and you take her to the OR. In the OR the appendix is gangrenous with necrosis extending to the base of the cecum. How do you treat this?

A

Ligate and amputate the appendix, cauterize the stump and bury the stump into the cecum. If the cecum is inflamed or has an associated mass perform a right colecotmy.

48
Q

A patient presents with appendicitis and you take her to the OR. In the OR the appendix is perforated w/local abscess. How do you treat this?

A

Remove the appendix, drain the abscess, irrigate and place a drain. Think about leaving the skin open to heal due to high likelihood of wound infection with complete closure.

49
Q

A patient presents with appendicitis and you take her to the OR. In the OR the appendix has a 1cm yellow firm mass at its tip. How do you treat this?

A

This is most likely a small carcinoid tumor. If < 2cm w/no evidence of local spread routine appendectomy can be performed. If > 2cm or base of appendix/cecum is involved perform right colectomy and reanastomosis. Check 5-HIAA and serum serotonin levels to determine the malignancy of the tumor (not TNMG). If this may be a recurrent lesion CT abdomen and octreotide scan can help you localize neuroendocrine tumors.

50
Q

A patient presents with appendicitis and you take her to the OR. In the OR you find a 3cm pedunculated mass in the terminal ileum that is obstructing the lumen. How do you treat this?

A

This could be carcinoid or adenocarcinoma. You need to remove the involved ileum and regional LNs. Also examine the rest of the bowel for multiple lesions (common with carcionoid). Check 5-HIAA and serum serotonin levels to determine the malignancy of the tumor (not TNMG). If this may be a recurrent lesion CT abdomen and octreotide scan can help you localize neuroendocrine tumors.

51
Q

How might you look for a pelvic abscess on physical exam of a patient who had appendectomy 1 week ago?

A

Tender mass on rectal exam. Confirm with CT and perc drain for tx.

52
Q

What are the screening guidelines for colorectal cancer in asymptomatic patients?

A

Average risk (age > 50 w/no other risk factors) can get yearly FOBT (high false-negative rate), FOBT every 3 years + sigmoidoscopy at 5 year intervals (misses 50% of clorectal polyps) or colonoscopy at 10-year intervals…all starting at age 50. Increased risk: 1st degree relative = same screening guidelines starting at age 40, FAP = genetic counseling and yearly flex sig (chance of colorectal cancer is 100%, so colectomy if + for polyps), HNPCC (Lynch syndrome) = genetic testing, colonoscopy every 1-2 years from age 20-40 and yearly after age 40, hx of large or multiple adenomatous polyp removal = f/u exam in 3 years, hx of resected colon cancer = colonoscopy 1 year after operation, screening at 3 years and then at 5 year intervals, CEA every 2-3 months if stages II-III for 2 years, LFTs and physical exam every 3-6 months. DO NOT SCREEN PATIENTS > 75 unless they are < 85 with favorable conditions for screening.

53
Q

Management of patient that presents with 2-3 hemorrhoids that only bleed with BMs

A

Conservative 1st: sitz baths, stool softeners and fiber. If they fail to resolve and are internal, you can band them or excise them. External hemorrhoids are excised. Depending on the patients age you may also want to get a colonoscopy or sigmoidoscopy to absolutely r/o colon cancer.

54
Q

Tx of thrombosed hemorrhoids

A

Conservative 1st: sitz baths and stool softeners. If extremely painful can go ahead with I&D, mild analgesics and sitz baths.

55
Q

Next step if you discover a 5cm perianal fungating mass on DRE

A

Bopsy and transanal u/s to determine depth of invasion.

56
Q

What is the adenoma-carcinoma sequence?

A
57
Q

A patient comes for routine colonoscopy and you perform polypectomy on a single 1cm pedunculated polyp. How do you manage this patient?

A

F/u w/path results. If invasive adenocarcinoma he will need colon resection. If not, f/u colonoscopy in 3-6 months and then surveillance colonoscopy every 3 years.

58
Q

When do you need to schedule surgical resection of a sessile polyp found on colonoscopy?

A

If > 2cm

59
Q

When is polypectomy alone sufficient for the patient?

A

Severe atypia or less or carcinoma in situ (no invasion into muscularis mucosa) in the head of the polyp with no extention into the stalk (hese patients should have f/u colonoscopy in 3-6 months and then in 12 month intervals) or carcinoma in the stalk of the polyp w/margin > 2mm, well-differentiated and no lymphovascular invasion. Otherwise, mark it with a tatoo and schedule the patient for resection.

60
Q

How do you manage a patient who had a sessile polyp on colonoscopy with invasive carcinoma?

A

Since risk of LN mets and local recurrence w/o resection is 15-20%, bowel resection is indicated w/repeat colo in 1 year.

61
Q

In addition to colonoscopy, CBC, CEA and CXR, what other tests should you order for a patient with a high index of suspicion for colon cancer?

A

CT liver and LFTs to r/o liver mets

62
Q

Where are the most common locations of colon cancer? How does the presentation differ by location?

A

50% in rectum, 20% in sigmoid, 5% in descending colon, 10% in transverse colon and 15% in ascending colon. Right sided colon cancer typically presents with weight loss, fatigue, a mass and pain. Left sided colon cancer typically presents with pain and obstruction (napkin-ring or apple core lesions cause intermittent constipation and diarrhea). Sigmoid colon cancer typically presents with bowel complaints and rectal cancer typically presents with bowel complaints + painless bleeding.

63
Q

It is the morning of the surgery for your patient having a colon resection for colon cancer. What is your plan for the patient?

A

Hopefully the patient completed bowel prep the day before (GoLYTELY, Mg-citrate + oral nonabsorbable abx). Before opening the patient give a single dose of cephalosporin. Once the patient is opened, explore the liver, diaphragm, small bowel and peritoneum for mets. Resect the appropriate side of the colon, regional LNs and then reanastomose bowel. Post-op the patient needs to be NPO of IVFs until bowel function returns.

64
Q

What types of colon cancer present with a particularly worse prognosis regardless of their actual stage?

A

Mucus-producing tumors, signet ring cell tumors, tumors presenting with perforation and tumors with venous or perineural invasion…note that these tumors merit adjuvant chemotherapy.

65
Q

How do you stage colon cancer?

A

Tx:Incomplete information.

Tis: CIS, involves only the mucosa, has not grown beyond the muscularis mucosa

T1: The cancer has grown through the muscularis mucosa and extends into the submucosa.

T2: The cancer has grown through the submucosa and extends into the muscularis propria

T3: The cancer has grown through the muscularis propria and into the serosa but not through it. It has not reached any nearby organs or tissues.

T4a: The cancer has grown through the serosa

T4b: The cancer has grown through the serosa and is attached to or invades into nearby tissues or organs.

Nx: Incomplete information.

N0: No cancer in nearby lymph nodes.

N1: 1-3 positive local LNs

N1a: 1 positive local LN
N1b: 2-3 positive local LNs
N1c: Positive perinodal fat, no cancer in actual LNs

N2: 4+ positive local LNs

N2a: 4-6 positive local LNs
N2b: 7+ local LNs

M0: No mets

M1a: 1 met to distant organ/LNs

M1b: > 1 met to distant organ/LN or distant part of peritoneum

Stage I (92% 5 year survival colon, 87% rectal, tx is polypectomy +/- partial colectomy w/LN dissection)

T1-T2, N0, M0

Stage IIA (87% 5 year survival colon, 80% rectal, tx is partial colectomy, chemorads is controversial, but if chemo is used it is 5-FU + leucovorin or capecitabine)

T3, N0, M0

Stage IIB (63% 5 year survival colon, 49% rectal)

T4a, N0, M0

Stage IIC

T4b, N0, M0

Stage IIIA (89% 5 year suvival colon, 84% rectal, tx is partial colectomy w/LN dissection + chemo w/5-FU, leucovorin, + oxaliplatin or chemo w/capecitabine + oxaliplatin. Rads is added case by case.)

T1-T2, N1, M0 or T1, N2a, M0

Stage IIIB (69% 5 year survival colon, 71% rectal)

T3-T4a, N1, M0 or T2-T3, N2a, M0 or T1-T2, N2b, M0

Stage IIIC (53% 5 year survival colon, 58% rectal)

T4a, N2a, M0 or T3-T4a, N2b, M0 or T4b, N1-N2, M0

Stage IVA (11% 5 year survival colon, 12% rectal, tx is partial colectomy w/LN dissection and mets resection + chemo or chemo alone +/- palliative colon resection to relieve obstruction)

Any T, Any N, M1a

Stage IVB (11% 5 year survival colon, 12% rectal)

Any T, Any N, M1b

66
Q

What is the standard follow up for a patient who had colon cancer resection?

A

Tell them that 70-90% of recurrences happen within 2-4 years and he needs repeat colo at 6 months and then at 1 year intervals. He also needs more frequenct CXR, CEA and LFTs to survey for mets.

67
Q

What is Lynch syndrome?

A

HNPCC is due to a mutation in MSH2 or MLH1 that causes DNA mismatch repair enzyme dysfunction and microsatellite instability.

68
Q

What is FAP?

A

Familial adenomatous polyposis is caused by AD first hit mutation in the APC gene of the adenoma carcinoma sequence. Colorectal carcinoma develops in 100% of patients by age 30.

69
Q

What liver lesions should you not resect at time of colectomy for patients with colon cancer?

A

Invasion of vessels or larger lesions, these increase operative risk significantly (bile leak and infection) and should be done at a later date after obtaining patient consent.

70
Q

A patient presents after having a hemicolectomy done with abdominal distention and feculent vomiting POD 3. How do you treat this patient?

A

He likely has bacterial overgrowth in the stomach and proximal small bowle due to either anastomoses leakage causing persistent ileus or mechanical obstruction due to adhesions, hernia or obstructed anastomosis. You should get a CT to identify the problem, put on IVF, NG and NPO.

71
Q

A patient presents after a hemicolectomy with feculen material draining from the inferior aspect of the incision. How do you treat this patient?

A

He likely has wound infection due to anastomotic leak. Tx with NPO and IVFf, most colon fistulas close with this therapy. If CT shows undrained fluid collection, drain it. If you are concerned about the patency of the anastomosis, you may have to revise it but should confirm patency with gastrofrafin enema or colo.

72
Q

What is your next step in a patient that presents with crampy abdominal pain, decreased stool caliber and constipation 6 months after hemicolectomy for colon cancer?

A

Colonoscopy to check for anastomotic recurrence of cancer or structure at anastomosis.

73
Q

Next step when you discover rectal adenocarcinoma

A

Transrectal u/s to determine tumor depth, CT/MRI to assess adjacent structures and distant mets (esp liver and LNs), CXR and CEA.

74
Q

Tx for apatient with rectal cancer confined to the bowel wall w/o LN spread or mets.

A

Abdominoperineal resection (takes the entire rectum w/permanent colostomy and excision of regional LNs).

75
Q

How do rectal carcinomas metastasize?

A

Lymphatic spread via the internal iliac nodes, sacral nodes and inferior mesenteric nodes if > 5cm from anal verge. Inguinal nodes can also be involved if < 5cm from anal verge.

76
Q

What are risks and complications of abdominoperineal resection?

A

Impotence (50% incidence to due proximity of sympathetic plexus), incontinence, massive bleeding from presacral space, ureter injury and colostomy complications.

77
Q

When do you do abdominoperineal resection vs. low anterior resection for rectal cancer? How big are your margins?

A

LAR if > 5cm from anal verge, abdominoperineal resection if < 5cm. This is because lateral margins in lesions < 5cm from anal verge include the sphincters. Both methods should have 2cm margins for well to mod differentiated and 5cm margins for poorly differentiated and larger lateral components.

78
Q

Most common cause of failure after surgically removing rectal carcinoma?

A

Local recurrence

79
Q

When do you use radiation for rectal cancer?

A

When it is large/bulky and needs shrinking before surgery or extends outside bowel wall.

80
Q

What procedures can you do to resect rectal cancer while preserving continence?

A

Sphincter-preserving proctectomy or coloanal anastomosis.

81
Q

How does surgery for rectal cancer differ in women compared to men?

A

You have to remove the posterior vaginal wall also.

82
Q

Early pelvic pain vs. later pelvic pain in patient post-op from LAR for rectal cancer?

A

Early = infection or nerve injury. Late = local recurrence.

83
Q

A patient presents for follow up surveillance after having colon cancer removed 2 years ago. His CEA is elevated today and CT abdomen reveals liver metastasis. What characteristics of the metastasis would make this non-resectable? What could you do if you can’t resect it?

A

Multiple lesions in multiple lobes, vascular invasion, local invasion, extrahepatic mets, can’t get 1cm margins or cirrhosis means no surgery. Survival rate if the lesion is resectable is 33% at 5 years. 15% if 1-4 lesions are present and 0% if unresectable. Aside from surgery you can try cryotherapy, ethanol injection, RF ablation or chemoembolization with Gelfoam saturated with chemotherapy.

84
Q

What is the most common cancer in the anal canal? Where does it like to metastasize?

A

Squamous cell. They commonly metastasize to inguinal LNs and superior rectal LNs.

85
Q

Tx for anal cancer

A

Local excision alone if small, superficial and mobile, otherwise chemorads is preferred for all other anal cancers due to preservation of sphincter (abdominoperineal resection only indicated if residual disease after 4-6 weeks of chemorads)

86
Q

Management of diverticulitis

A

Fluids only diet + broad spectrum abx 7-10 days in outpatient and increase dietary fiber. If clinical picture is more serious complete bowel rest, IVF, IV abx and meperidine for pain (decompresses bowel as opposed to morphine that can cause increased pressure). You should check obstructive series to r/o perf and consider CT to check for inflammation, abscess, diverticul and thickened sigmoid bowel wall…all of which would confirm diverticulitis.

87
Q

Long-term f/u for diverticulitis

A

70% have no further recurrences, but you should do colonoscopy after recovery to make sure there is no colon cancer.

88
Q

When should you advise a patient for resection of diverticula?

A

After 2nd episode of diverticulitis you can recommend elective resection 4-6 weeks later to avoid complications of perf or abscess with subsequent episodes.

89
Q

Management of a patient with abscess due to diverticulitis?

A

Drain the abscess, admit until tolerates solids and remains afebrile. Schedule colonoscopy and single-stage colectomy (reanastomosis w/o colostomy) 4-8 weeks after inflammation is controlled. If patient clinically worsens do a a Hartmann procedure w/resection of inflammatory mass and colostomy.

90
Q

Most common causes of rapid lower GI bleeding? How do you confirm that it’s not upper GI bleeding in the ED?

A

Bleeding diverticula and vascular ectasias. Other common causes are Meckel’s, aortoenteric fistula, ischemic colitis, IBD, hemorrhoids and rectal varices. Confirm it’s not upper GI by NG tube placement. Figure out what the lower GI cause is by colonoscopy.

91
Q

How do you know if you should transfuse a patient if they had a massive bleed but their hematocrit is initially normal?

A

Check it every few hours because it takes a while for it to normalize after a massive bleed.

92
Q

Tx for massive lower GI bleed due to vascular ectasia

A

Vascular ectasias are AVMs due to degeneration of intestinal submucosal veins and overlying mucosal capillaries, resulting in submucosal artery and vein communications. Monopolar coagulation, make sure not to perforate the colon though!

93
Q

Tx for massive lower GI bleed due to diverticular rupture

A

Tattoo w/methylene blue or India ink for localization during surgery.

94
Q

Why are diverticula associated with heavy lower GI bleeding?

A

Vasa recta arteries that penetrate the diverticulum become eroded. Note that although left sided diverticula are more common, right sided diverticula bleed more.

95
Q

How do you diagnose the cause of massive GI bleed when patients fail to respond to transfusions and continue to bleed?

A

Technetium-labeled RBC scan (isolates bleeds of 0.1 mL/min, but can’t localize bleeding site well) or mesenteric angiography (isolates bleeds of 0.5-1.0 mL/min, use if less stable and bleeding more rapidly) to find the cause, then send the patient to surgery even if you can’t identify the cause once 4-6 units of blood have been given.

96
Q

Surgical approach for massive lower GI bleed in a patient with unspecified dx

A

Left or right hemicolectomy to remove the bleeding source, anything less than that with an unsure dx increases the risk of rebleeding. Explore the whole abdomen b/f colectomy. Finish w/primary anastomosis unless pt is unstable or malnourished.

97
Q

When can you take a patient with a massive lower GI bleed to the OR before they receive 4-6 units of transfused blood?

A

Pt is unstable w/continued bleeding (CAD or angina w/unstable vitals) and patients with hard-to-determine blood types or Jehovah’s Witnesses. Just remember, never bypass the pre-op angiogram because it will be very difficult to find the bleeder and you will end up doing a total abdominal colectomy.

98
Q

What can you do during mesenteric angiogram to lessen the bleeding while you prep the patient for surgery?

A

Inject vasopressin temporarily into the bleeding vessel but beware of its coronary vasoconstrictor effect and risk of rebleeding in 12 hours. You can also embolize the bleeder, but realize the risk of intestinal necrosis.

99
Q

What are populations that commonly have sigmoid volvulus?

A

Chronic laxative use, chronic illness and demented patients

100
Q

What causes sigmoid volvulus and how do you treat it?

A

Clockwise twisting of the mobile sigmoid colon around the mesentery causes a closed loop obstruction. Confirm dx by barium enema, tx with rigid proctosigmoidoscopy and placement of rectal tube to untwist sigmoid colon.

101
Q

Next step if decompression of sigmoid volvulus fails with rigid proctosigmoidoscopy?

A

Diverting colostomy or resection w/primary anastomosis. Note that this should be done anyway because risk of recurrence is ~30%.

102
Q

Tx of cecal volvulus

A

Surgical detorsion, cecopexy or right colectomy. In stable patients with viable bowel the operation of choice is right colectomy with primary anastomosis due to risk of recurrence.

103
Q

A patient in the ICU is intubated and severely ill. He starts have symptoms of bowel obstruction and intense pain. Abdominal radiograph shows acute massive dilation of the cecum and right colon with no evidence of mechanical obstruction. How do you treat her?

A

This is Ogilvie’s syndrome. This is treated nonoperatively if cecal dilation is < 9-10 cm. If diameter is > 11-12 cm, endoscopic decompression is indicated + neostigmine (parasympathetic agonist to increase colon tone). If this fails you must resort to surgical decompression of the cecum (stoma) or right colectomy.

104
Q

A patient presents with severe constipation. Radiographs show a colon packed with stool. How do you treat this patient?

A

DRE to check for stool impaction. If impacted manually clear rectal vault then give cathartics PO.

105
Q

When can patients avoid surgery for rectal prolapse? What are the surgical options for rectal prolapse?

A

If the prolapse is entirely internal and there is no bleeding. These patients can take stool softeners and increase fiber. If the prolapse is external and causes bleeding w/no other GI causes there are a number of operations which include: rectopexy, LAR, perineal approach resection of prolapsed rectum and sigmoid colon w/anastomosis above dentate line.

106
Q

Tx options for patients with anal fissures

A

Conservative: sitz baths, stool softeners and bulk agents. Surgical: lateral sphincterotomy to divide a portion of the internal sphincter and decrease reflex spasm of the internal anal sphincter with stool passage. Also biopsy lesion to r/o anal cancer. 90% of fissures heal with lateral sphincterotomy.

107
Q

How do you tx fistula in ano?

A

Unroof the sinus tract from the internal anal crypt to the external opening in the perianal skin, drain any undrained fluid and allow the tract to re-epithelialize. Note that if the tract traverses an anal sphinter a seton should be placed to retain continence.

108
Q

What are the 4 types of perianal abscesses and how does management of each differ?

A

Perianal and ischiorectal can be drained through a perianal incision. intersphincteric requires drainage from inside the anal canal. Supralevator drainage depends on its origin and termination.

109
Q

Tx for pilonidal abscesses

A

Unroof the cysts, remove all hair and leave open to heal by secondary intention.

110
Q

Complications associated with stomas

A

Leakage, patient dissatisfaction w/location, parastomal herniation, bowel obstructino abscess and fistula formation

111
Q

What are the different types of stomas?

A

Loop stomas (double barrel), distal bowel stomas (mucous fistulas b/c no stool passes through due to proximal stoma drainage), Hartmann pouch, and cecostomies.

112
Q

When do you use permanent stomas?

A

After abdominoperineal resection w/end sigmoid colostomy, after total proctocolectomy for UC with ileostomy (undone by ileoanal pullthrough) or ileal conduit draining the urinary system to the skin.

113
Q

A patient presents a year after having a Hartmann pouch and colostomy done with fever, weakness and abdominal pain. How should you treat him?

A

This is likley pouchitis. Tx with metronidazole.

114
Q
A