Colonoscopy Indications - PowerPoint Presentation

1. Colonoscopy Indications Asst Prof Faisal Elagili, M.D.MS.FASCRS

2. Colonoscopy Colonoscopy is an examination to inspect the inner lining of the large bowel (rectum and colon) using a flexible tube with a camera at its tip. It is inserted via the anus and gently guided to the start of the large bowel (caecum).

3. IndicationsLower GI bleedingScreening and surveillance of colorectal polyps and cancersa. Colon cancerb. Surveillance after polypectomyc. Colorectal cancer post-resection surveillanced. Inflammatory bowel diseasesAcute and chronic diarrheaTherapeutic a. Excision and ablation of lesionsb. Treatment of lower GI bleedingc. Colonic decompressiond. Dilation of colonic stenosise. Foreign body removal5.Miscellaneous a. Abnormal radiological examinationsb. Isolated unexplained abdominal painc. Chronic constipationd. Preoperative and intraoperative localization of colonic lesions

4. ContraindicationsAbsolute contraindicationsPatient refusal Uncooperative patients Inadequate sedationKnown or suspected colonic perforation Severe toxic megacolon and fulminant colitis PeritonismSevere coagulopathiesAcute diverticulitisRelative contraindicationsVery large abdominal aortic aneurysms (particularly if they are symptomatic) Patients who are immediately postoperative Clinically unstable patients Recent myocardial infarction or pulmonary embolismPregnancy

5. Patient PreparationSigned informed consentRoutine laboratory testing is not necessaryOral iron therapy and bismuth-containing medications must be discontinued Constipating medicines should be stopped 48 hours Blood pressure medications are usually administered on the day of the procedure.

6. Patient Preparation Patients on beta blocker are more susceptible to intraprocedural bradycardia, and atropine should be available during the procedureAspirin,antiplatelet and NSAIDsDiagnostic endoscopy with biopsy appears to be safe Therapeutic

7. Patient PreparationChronic anticoagulationDiagnostic without biopsy May be performed as long as the international normalized ratio (INR) is maintained in the therapeutic range of 1.5 to 2.5Therapeutic Low thrombotic riskWarfarin therapy is discontinued 5 daysHigh thrombotic riskWarfarin should be temporarily discontinued 5days Low molecular weight heparinLMWH

8. Clear Liquid DietColonic preparation is improved by a ‘‘clear’’ liquid diet for one day before the colonoscopyBeverages: coffee, tea.Desserts: Jello, clear popsiclesFruit: Apple juice, cranberry juice, grape juiceSoups: clear brothSweets: hard candy, sugar.

9. Colonic preparationFleet Phospho-soda45 cc evening prior to and on the day of the procedure 4–6 hours before colonoscopyRelatively contraindicated in patients with renal insufficiencyPolyethylene glycol (PEG)Patients must drink all 4 liters of prescribed PEG solution to adequately cleanse the colonContraindicated in patients with suspected complete GI obstruction, and in patients with fluid overload

10. Patient PreparationAntibiotic prophylaxis In high-risk patients (eg, those with prosthetic valves, a previous history of endocarditis, complex cyanotic congenital heart disease, surgically constructed pulmonary shunts or conduits, or joint replacements)The most commonly used preprocedure and postprocedure prophylaxis regimens are as follows:Ampicillin or amoxicillin, 2 g IV/IM or 1.5 g orallyGentamicin, 1.5 mg/kgVancomycin, 1 g IV

11. SedationVersed and FentanylContinuous monitoringReversal if needed

12. Colonoscopy Inseration TechniqueThere are 6 major conceptsKeep the colonoscope straight.Torque steering of the instrument shaft.Position change and abdominal pressure.Minimize gas insufflation Avoid push unless you know where the tip is going.Never let the left thumb leave the up/down dial.

13. Colonoscopy Inseration TechniqueThe endoscopist tests all instrumental ports and manual controls before instrument insertionLeft lateral positionThe anal area inspectionDigital rectal examinationThe instrument tip, supported by the forefinger, is pressed gently and obliquely against the external sphincter until the sphincter relaxes, and inserted blindly a few cm into the rectum

14. Colonoscopy Inseration TechniqueThis insertion may produce a‘‘red-out’’Colonoscopic advancement is deliberate with the lumen in viewMucosal surfaces are meticulously inspected, particularly areas behind folds, around flexures, and within regions of diverticulosis. Air insufflation is used sparinglyExcessive air insufflation can precipitate instrument looping

15. Colonoscopy Inseration TechniqueSplenic flexure intubationAided by Clockwise torque of the instrument shaftWith external splinting of the sigmoid colon by the endoscopy assistant.After intubating this flexure, the tip of the instrument can be hooked onto the transverse colon wall, and the shaft modestly withdrawn to reduce any sigmoid loop and straighten the instrument

16. Colonoscopy Inseration TechniqueHepatic flexure intubation Advanced using clockwise torque while the endoscopy assistant supports the midtransverse colon to prevent looping Colonoscopic suction helps maintain tip position within thecolon during brief shaft withdrawalTo help intubate the cecumThe patient can be turned from the left lateral to the right lateral position to use gravity to advance the colonoscopic tipAir can be aspirated from the ascending colon to shorten its length

17. Colonoscopy Inseration TechniqueCecal intubation is critical to complete colonoscopy and not miss a proximal colonic lesion. Appears as a closed capacious sac, bounded distally by the prominent ileocecal valve, and bounded proximally by the convergence of the curvilinear impressions formed by the three taeniae coli (‘‘Mercedes Benz’’ sign) at the caput (apex) of the cecum.The appendiceal orifice may be visible near the caput. It appears as a small dimple-like depression, surrounded by a small fold or slightly raised circular mound.

18. EXTUBATION TECHNIQUEClose examination of the colonic mucosa is best done during extubationMinimum withdrawal time of 6 min is required to gain an adequate ADRThe key points to remember are as followsInflate enough to get clear views (then aspirate once a segment has been examined).Rotate fluid to the 6 o’clock position so it is easily and accurately suctioned.Take care to examine behind flexures and folds.Reinsert the colonoscope if you fall back too quickly to avoid missing sections of mucosa.Consider using position change to optimize the view.

19. The Final Step-Retroflexion Fully inflate the rectum, and then manipulate the shaft gently into a U-turn position; using the lateral wheelRectum or possibly the cecum, where the colonic lumen is widestDangerous in a segment with diverticulosis

20. The Final Step-RetroflexionUseful to detect distal rectal pathology,including internal hemorrhoids, anal fissures, condyloma acuminata, and distal rectal tumors

21. The difficult colonoscopyOne in which the endoscopist struggles or fails to reach the cecum Factors Loops or angulation in the colonDiverticular disease The quality of the preparationThe patient’s body habitusAbdominal hysterectomyFemale

22. The difficult colonoscopyFailure to advance when lumen is visualized is usually caused by a colonic loopMucosal traumaAbdominal pain from colonic stretch.Loops most commonly form in the sigmoid, descending, or transverse colon.

23. The difficult colonoscopyA loop is often reduced bySuctioning airTorque in the opposite direction from the loopJiggling the colonoscope back and forthPatient repositioningModest colonoscope withdrawalRight turn/left turn shortening

24. The difficult colonoscopyLoop reduction is indicated byRestoration of a one-to-one correspondence between colonoscope shaft and tip movementsAmelioration of the patient’s painLoops are prevented bySuctioning excessive airTurning the colonoscope tip using torqueExternal splinting of the colon by the endoscopy assistantJiggling the colonoscope back and forth to pleat, shorten, and straighten the colon over the colonoscope

25. The difficult colonoscopy‘‘Slide-by’’ maneuverThe endoscopic tip is advanced, without visualization of colonic lumen, to negotiate a sharp turn.When the direction of the lumen is known and the colonoscope tip is turned in this directionContraindicated in an area ofDiverticulosisStrictureActive colitisColonic mass

26. The difficult colonoscopySuccessful slide-by is indicated by rapid passage (‘‘spinning’’) of mucosa across the colonoscopic lens without colonic resistance to colonoscopic advancement until lumen reappearsUnsuccessful slide-by is indicated by arrest of mucosal motion across the lens, colonic resistance to colonoscopic advancement

27. The difficult colonoscopy‘Tricks’ to increase cecal intubation rates Limit the air used on intubation, or to suction air when encountering difficult angulationChanging the position of the patien When too much loop has been left in the colon and the cecum cannot be reached, the solution is sometimes to withdraw the endoscope,take out the troublesome loop, and reintubate the colon with great careUse of a thinner endoscope, such as a pediatric colonoscope

28. Colonoscopy RisksPerforation 0.1%Hemorrhage (polypectomy),0.1%-0.6%Cardiovascular and pulmonary complications related to sedation 0.9%Transient bacteremia after colonoscopy, with or with polypectomyPostpolypectomy electrocoagulation syndrome 0.003% to 0.1%Explosive complications of colonoscopy are rareAbdominal distention and pain

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