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Colonoscopy. Scott M. Strayer, MD, MPH Associate Professor University of Virginia Health System Department of Family Medicine. A Case. 45 yo male presents with rectal bleeding X1. Physical exam reveals small non-thrombosed hemorroid. What other history would you like to have?
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Colonoscopy Scott M. Strayer, MD, MPH Associate Professor University of Virginia Health System Department of Family Medicine
A Case • 45 yo male presents with rectal bleeding X1. • Physical exam reveals small non-thrombosed hemorroid. • What other history would you like to have? • Are any further tests warranted?
One more case • 50 year old presents for physical exam. • What questions would you ask to determine preferred method of colon cancer screening.
Colon Cancer • 150,000 cases per year. • 50,000 deaths annually. • #2 cause of cancer mortality in non-smoking males and females.
Screening Recommendations • The USPSTF strongly recommends that clinicians screen men and women 50 years of age or older for colorectal cancer. (A recommendation) • Good evidence that periodic fecal occult blood testing (FOBT) reduces mortality from colorectal cancer and fair evidence that sigmoidoscopy alone or in combination with FOBT reduces mortality. Insufficient evidence that newer screening technologies (e.g., computed tomographic colography) are effective in improving health outcomes.
Screening Recommendations • AAFP-No published standards or guidelines for low-risk patients • ACOG-After age 50, annual FOBT (DRE should accompany pelvic examination); sigmoidoscopy every 3 to 5 years • ACS-After age 50, yearly FOBT plus flexible sigmoidoscopy and DRE every 5 years or colonoscopy and DRE every 10 years or double-contrast barium enema and DRE every 5 to 10 years
Screening Recommendations • AMA-Annual FOBT beginning at age 50, and flexible sigmoidoscopy every 3 to 5 years beginning at age 50 • AGA-FOBT beginning at age 50 (frequency not specified); sigmoidoscopy every 5 years, double-contrast barium enema every 5 to 10 years or colonoscopy every 10 years.
Screening Recommendations • CTFPHC-Insufficient evidence to recommend using FOBT screening in the periodic health examination of individuals older than age 40; insufficient evidence to recommend sigmoidoscopy in the periodic health examination; insufficient evidence to recommend screening with colonoscopy in the general population • USPSTF-After age 50, yearly FOBT and/or sigmoidoscopy (unspecified frequency for sigmoidoscopy)
The Evidence • Screening for colorectal cancer reduces cancer-related mortality at costs comparable to other cancer screening programs. Given an expected screening compliance rate of 60% and current costs of the various procedures, annual rehydrated fecal occult blood testing plus sigmoidoscopy every 5 years is most cost-effective. If the cost of colonoscopy is reduced by 25% or more, screening every 10 years with colonoscopy is preferred by this model (LOE: 2b). Frazier AL, Colditz GA, Fuchs CS, Kuntz KM. Cost-effectiveness of screening for colorectal cancer in the general population. JAMA 2000;284:1954-61.
More Evidence • 16% of colorectal cancers prevented with FOBT. • 34% of colorectal cancers prevented with flex sig. • 75% prevented with colonoscopy. • Colonoscopy q 10 years was more cost-effective than flex sigs q 5-10 (LOE:?). Sonnenberg A, et al. Cost-effectiveness of colonoscopy in screening for colorectal cancer. Ann Intern Med October 17, 2000;133:573-84.
Even More Evidence • Screening with sigmoidoscopy: There is evidence from case control studies, to recommend that flexible sigmoidoscopy be included in the periodic health examination of patients over age 50 [B, II-2, III]. There is insufficient evidence to make recommendations about whether only 1 or both of fecal occult blood testing and sigmoidoscopy should be performed [C, I]. CMAJ 2001 Jul 24;165(2):206-8 [20 references]
Is there enough time for prevention? • Patient panel of 2500 • Age and sex distribution similar to US pop. • To fully satisfy the USPSTF recs, it would take 1067 hours per year or 4.4 hours per working day of a physician’s time • If you include children and pregnant women: 1621 hours per year / 6.8 hours per day
Priorities among recommended clinical preventive services Coffield AB, Maciosek MV, etal. Am J Prev Med 2001;21(1):1-9.
Is it cost effective? • Flex sig with FOBT Q 5 years-$92K per life year saved. • Pap smears Q year-$99K per life year saved. • Annual mammogram (55-64)-$132K per life year saved. Frazier AL, Colditz GA, Fuchs CS, Kuntz KM. Cost-effectiveness Of screening for colorectal cancer in the general population. JAMA 2000:1594-1961.
New Developments Pignone M, Levin B. Recent Developments in Colorectal Cancer Screening and Prevention. American Family Physician 2002:297-302.
Screening Capacity • National screening program would require approx. 10m procedures (double current levels) annually or 5m colonoscopy procedures (increase of 20%). • Not enough surgeons and GI’s to perform the additional colonoscopies.
Indications • Should consider colonoscopy if: previous polyps, family history of colon cancer, rectal bleeding, hemoccult positive stools, change in bowel habits, protracted diarrhea, surveillance in UC/Crohn’s, anemia, unexplained wt. Loss/fevers, abdominal pain.
Contraindications • ABSOLUTE • Acute, severe cardiopulmonary disease. • Inadequate bowel prep. • Active diverticulitis • Acute abdomen. • History of SBE or prosthetic valves with no prophylaxis. • Marked bleeding dyscrasia.
Contraindications • RELATIVE • Recent abdominal surgery (bowel or pelvic). • Active infection • Pregnancy.
Additional Equipment • Light source • Suction apparatus • Biopsy forceps • K-Y Jelly • 4X4 inch gauze pads • Nonsterile gloves • Water container (for suction)
More equipment • Video unit and monitor • Anoscope • Basin of water • Formalin jars • Disinfecting cleaner
Complications • Bowel perforation (1-2/1000) • Complications from sedation • Bleeding (increased risk with biopsy) • Abdominal distention and pain • Infection (SBE, infection from another pt.) • Vasovagal symptoms • Missed disease
Increased Complications • Watch out for patients with previous bowel or pelvic surgery, irradiation, or diverticulosis. • Caution with blind advancement (only limited distances).
Patient Preparation • Signed informed consent • Fleets phosphorous soda X 2 or Golytely • Abx prophylaxis for high risk (e.g. hx of endocarditis, prosthetic valves, vascular graft-1st year) • Clear liquids day before exam and of exam • Take laxative if chronic constipation • Take normal medications (caution with diabetics)
Clear Liquid Diet • Beverages: carbonated, coffee, kool-aid (avoid red), tea. • Desserts: Jello, clear popsicles • Fruit: Apple juice, cranberry juice, grape juice • Soups: Beef bouillon, clear broth • Sweets: hard candy, sugar.
The Procedure • Pt. Placed in left lateral decubitus position • Rectal examination first • Lubrication is key, don’t smear the lens • Either directly insert scope, or flex index finger behind the scope. • Hold scope in left hand, use thumb for up and down, use right hand for right-left (or can also use thumb).
Sedation • Versed and Fentanyl • Continuous monitoring • Reversal if needed
Rectum • Insert scope 7-15cm, insufflate and/or withdraw to visualize lumen • Normal rectal mucosa is a nonfriable, vascular network. • Proctitis produces an erythematous, friable mucosa, often with bleeding. • Semilunar valves of Houston appear as sharp edges protruding into the lumen (there are 3) with shadows noted behind them.
Rectum • Ulcerative colitis will produce erythema, friability, and mucosal bleeding.
Sigmoid • Redundant folds, hard to visualize lumen • May have to: insufflate, extensive turning, torquing, accordionization, or dithering • Avoid bowing out. • Most common place for perforations
FIGURE 1.Hooking and straightening technique used to pass through a tortuous sigmoid colon. (A) The scope is inserted to the angled sigmoid. (B) The scope tip is turned to a sharp angle, and the sigmoid is hooked as the scope is withdrawn. (C) The sigmoid is straightened as the scope is withdrawn. The scope can then be inserted through to the descending colon. Techniques
FIGURE 2.Paradoxic insertion. (A) The scope is bowing out the sigmoid colon, which has a mobile mesenteric attachment. (B) Paradoxic insertion describes the insertion of the tube without advancement of the scope tip. Paradoxic insertion can be very uncomfortable for the patient. Other Techniques
Descending Colon • Long, straight tube with concentric haustrae. • Vascularity is random, reticular. • Polyps can either be mound-like (sessile) or on a long stalk (pedunculated). • Don’t mistake suction polyps or mucous for polyps!!
Transverse Colon • After splenic flexure (often blind curve) • Triangular appearance • Fairly straight • Hepatic flexure (blue-brown area where livers is in contact with bowel wall)
Ascending Colon • Also triangular • Advance to cecum by pulling back, using suction, often releasing right lower quadrant abdominal pressure • Identify landmarks • Ileocecal valve • Appendiceal Orifice • Terminal Ileum
The Final Step-Retroflexion • Accomplished by turning inner knob all the way “up” and outer knob all the way “right” while gently inserting and rotating 180 degrees. • Make sure you are in rectum, and not to far from internal sphincter.