Introduction
Colonoscopy refers to the endoscopic
examination of the entire colon and rectum and often includes the
terminal ileum. Common activities performed during colonoscopy include
inspection, biopsy, photography, and video recording. The procedure is
technically challenging and requires considerable training and
experience. High-quality examinations require good clinical judgment,
anatomy and pathology recognition, technical skill in manipulating the
scope and performing biopsies, appropriate patient monitoring, and
well-maintained and clean equipment to ensure patient safety. Video
colonoscopes enable complete examinations of the entire colon in more
than 90% of examinations.
Most colorectal cancers appear to
develop from benign neoplastic (adenomatous) lesions. Americans of
average risk have a 6% lifetime risk of developing colon cancer.
Adenomas occur in about 30% of individuals at age 50 years and
55% at age 80 years. Several screening modalities are advocated
to detect early adenomas and cancer, including colonoscopy every 10
years after age 50. Colonoscopy has sensitivities of 75% to
85% for polyps <1 cm in diameter and 95% for larger
polyps and cancers. The specificity for the examination approaches
100%.
A single screening colonoscopy in
asymptomatic individuals at age 65 has been advocated for reducing
mortality from colorectal cancer. Several analyses have suggested that a
single screening or repeated screenings every 10 years after age 50 may
be a cost-effective strategy. Despite increased insurance coverage for
colonoscopy screening, the feasibility of screening an entire population
has yet to be established.
View OriginalView Original
Colonoscopy is the diagnostic procedure
of choice for patients with a positive fecal occult blood test (FOBT).
Approximately 50% of individuals with a positive FOBT have a
neoplastic lesion (adenomas, 38%; cancer, 12%) at
endoscopy. Patients with long-standing ulcerative colitis should undergo
colonoscopy with biopsy to examine for dysplasia beginning 8 years after
the development of pancolitis or 15 years after the development of
distal disease.
Colonoscopy is indicated for villous
adenomas of any size that are discovered during flexible sigmoidoscopy.
Distal tubular adenomas are not associated with an increase in proximal
adenomas, and some clinicians do not believe that colonoscopy is
required after removal of a small, distal tubular adenoma. Historically,
adenomas >1 cm in diameter have been referred for colonoscopy.
Larger colonic lesions are more often villous or tubulovillous,
necessitating colonoscopic removal of the lesion and examination for
synchronous lesions. Some studies suggest that purely tubular lesions
>1 cm in diameter can be followed without immediate colonoscopy.
This strategy may be problematic, because a biopsy sample from within a
large lesion may fail to recognize the most significant pathology (i.e.,
missed villous or cancerous elements). Despite some contrary opinions,
colonoscopy is generally not indicated after the diagnosis of a
hyperplastic distal polyp.
Average procedure times for experienced
endoscopists are about 10 minutes to reach the cecum and 30 minutes to
complete the entire procedure. Inadequate preparation is the most common
reason for prolonged or incomplete examinations. Most individuals in the
United States receive 3 to 4 L of a polyethylene glycol " based
electrolyte solution the day before the examination. Some studies have
suggested that longer procedures and greater discomfort occur in women
undergoing the procedure, possibly because of their anatomically longer
colons and greater sigmoid mobility. Older individuals may present
greater difficulty in reaching the cecum.
Colonoscopy routinely is performed after
the administration of conscious sedation. Intravenous midazolam and meperidine have been the drugs most commonly
employed. Unfortunately, 15% of individuals receiving these two
medications are dissatisfied with their sedation. Propofol is an intravenous, short-acting sedative
used for the induction of general anesthesia. Propofol may provide superior sedation and more
rapid recovery, but its safety in office situations has not been
demonstrated. Studies have shown that the procedure can be performed in
selected individuals without sedation, with relatively high (70%
to 85%) rates of patients willing to undergo a similar procedure
again without sedation. Many physicians feel more comfortable with
routine administration of sedation to improve procedure acceptance among
patients. Procedural (Conscious) Sedation contains guidelines for
monitoring the patient receiving conscious sedation at endoscopy.
Polypectomy is the most commonly
performed therapeutic procedure during colonoscopy. With regard to
polyps found at the time of endoscopy, 85% to 90% can be
removed with the endoscope, but patients can experience considerable
morbidity from bleeding or colon perforation due to polypectomy. There
is a strong relationship between complication rates of diagnostic and
therapeutic colonoscopy and the experience of the endoscopist. The
highest rates of these complications appear in the first 500
procedures.
Colonoscopy can be safely learned only
with direct, one-on-one supervision by an experienced proctor or
preceptor. Debate exists about the number of procedures that trainees
need to perform to become competent in colonoscopy, and no scientific
data currently exists correlating the volume of colonoscopies performed
with acquisition of competence. Individual practitioners have varying
levels of manual dexterity and experience with flexible sigmoidoscopy
and can acquire skills at differing rates. Studies show that when
observable factors are used to determine technical competency in
colonoscopy (reach-the-cecum rate, time to complete procedure, and rate
of complications), family physicians, gastroenterologists, and general
surgeons are all comparable.
Equipment
- Conscious sedation drugs
and equipment - Colonoscope and video
monitoring equipment - Biopsy forceps, snare,
electrosurgical generator
Indications
- Evaluation of a
radiographic abnormality - Screening of asymptomatic
individuals for colon neoplasia or cancer - Evaluation of unexplained
gastrointestinal bleeding - Positive FOBT
- Unexplained
iron-deficiency anemia - Examination for a
synchronous colon neoplastic lesion when a lesion is found in
the rectosigmoid - Surveillance or follow-up
study after removal of a prior neoplastic lesion - Suspected inflammatory
bowel disease or surveillance for previously diagnosed
inflammatory bowel disease - Evaluation of symptoms
suggestive of significant colon disease (e.g., chronic diarrhea,
weight loss, abdominal or pelvic pain) - Therapeutic procedures
(e.g., polyp removal, foreign body removal)
Contraindications (Relative)
- Fulminant colitis
- Acute diverticulitis
- Hemodynamically unstable
patient - Recent (<3 months)
myocardial infarction - Recent (<1 week)
bowel surgery - Uncooperative patient
- Coagulopathy or bleeding
diathesis - Known or suspected
perforation - When the procedure
results will not produce a change in management
The Procedure
Step 1
The patient is placed on the
examination table in the left lateral position. Intravenous access
is obtained, and sedation is administered. Appropriate patient
monitoring includes frequent vital signs, oximetry, and heart rhythm
(electrocardiographic) evaluation throughout the procedure. Flexible Sigmoidoscopy provides instruction for
scope insertion and examination techniques in the rectosigmoid
during colonoscopy.
Step 1 View Original Step 1 View Original
Step 2
Traversing the rectosigmoid
junction is the one of the most difficult aspects of the procedure.
Prior pelvic surgery may produce extensive adhesions in this area
(see Flexible Sigmoidoscopy for techniques to pass
through this area). Insert the scope only through visible lumen. The
wall of the descending (left) colon has a characteristic circular
appearance with encircling folds.
- PITFALL: Sliding the scope along the colon
wall (i.e., slide-by technique) is not advocated, as this
technique may result in perforation at the rectosigmoid
junction.
Step 2 View Original Step 2 View Original
Step 3
A sharp turn appears at the
splenic flexure. A bluish color of the vascular spleen may be
visible through the colon wall.
Step 3 View Original Step 3 View Original
Step 4
A sharp turn of the scope tip
(with torquing) often is required to pass through the splenic
flexure.
The lumen of the transverse
colon has a characteristic triangular appearance.
Step 4 View Original Step 4 View Original
Step 5
The passage through the
transverse colon is relatively straight. Another sharp angle exists
at the hepatic flexure. The hepatic flexure can be identified by the
bluish brown shadow of the liver seen through the colon wall.
Step 5 View Original Step 5 View Original
Step 6
The examiner may notice
transillumination through the left upper abdominal wall from the
endoscope light. The assistant can press down on the
patient 's right upper abdomen to facilitate the downward
deflection of the scope tip into the ascending (left) colon. The
ascending colon has a characteristic pattern of mucosal folds that
do not encircle the lumen completely.
Step 6 View Original Step 6 View Original
Step 7
Avoid the creation of loops
within the colon, which can increase discomfort and risk of
complications. Keep the instrument as straight (short) as possible.
Repeated short insertions and withdrawals and aspiration of air at
the flexures can pleat the colon wall onto the instrument. Abdominal
pressure by the assistant can eliminate loops in the transverse or
sigmoid colon and facilitate more rapid insertion.
Step 7 View Original Step 7 View Original
Step 8
Traversing the left colon can
be challenging. The scope tip is advanced by pulling back on the
endoscope, causing paradoxical insertion. The scope tip is centered
in the lumen, and suction is applied to further advance the scope
through the colon. The ileocecal and appendiceal orifices may be
recognized when the cecum is reached. The appendiceal orifice
(shown) often appears on a "crow 's foot, " and
the three taeniae form a confluent fold leading to the orifice. In
many examinations, the appendiceal orifice may not be seen. Feeling
the scope tip in the patient 's right lower quadrant through
the abdominal wall or seeing the light transilluminating through
abdominal wall can help to assure the endoscopist that the cecum has
been reached, but seeing landmarks such as the appendiceal orifice,
"crow 's foot, " and ileocecal valve are
necessary to confirm the scope 's location within the
colon.
Step 8 View Original Step 8 View Original
Step 9
Attempt to intubate the
ileocecal orifice, which often appears as a slit on the medial wall
3 cm above the pole (i.e., most proximal portion) of the ascending
colon. First, aspirate the fluid from the cecal pole. The ileocecal
orifice often is angled downward, and several attempts may be
required for intubation. Angle the scope tip toward the orifice, and
position the tip just past the orifice. Gently withdraw the scope
until the angled tip flattens the D-shaped mucosal fold.
Step 9 View Original Step 9 View Original
Step 10
After the instrument
visualizes the ileocecal orifice and the valve begins to open, the
instrument is straightened and advanced. Paradoxical advancement by
withdrawal of the scope can aid in entering the terminal ileum. The
terminal ileal mucosa has a characteristic
"cobblestone " appearance.
Step 10 View Original Step 10 View Original
Step 11
Visualization is performed on
withdrawal of the scope. Withdrawal must be slow, with careful
inspection of the entire circumferential wall before the scope is
moved. Inspect behind every fold to ensure that hidden lesions are
not missed. After a polyp is discovered, the scope is positioned a
few centimeters away. The electrocautery snare is inserted through
the biopsy channel. The snare sheath is positioned next to the
polyp, the wire loop is advanced over the polyp, and the wire loop
is slowly secured over the base of the polyp or pedicle. In order to
reduce the risk of performation, the scope tip is maneuvered so that
the snare loop is not touching the colon wall. Apply the
electrocautery current.
- PITFALL: Colonic explosion has occurred in
individuals undergoing electrosurgical polypectomy.
Explosion of intraluminal methane gas is unlikely if the
colon has been adequately prepped.
Step 11 View Original Step 11 View Original
Step 12
Small polyps can be retrieved
through the scope using the snare or grasping forceps. Larger polyps
can be removed by suctioning the polyp against the scope and
withdrawing the scope.
- PITFALL: Reinsertion of the scope may be
needed if the scope has to be withdrawn to remove a large
polyp. The polyp may obscure the scope tip, making adequate
visualization of the colon wall during withdrawal
difficult. - PITFALL: Occasionally, polyps fall away or
are mishandled, or a large number must be removed.
Unretrieved polyps can be recovered after the procedure.
Patients may strain to move them out of the colon, or added
bowel prep solution (i.e., polyethylene glycol solution or
phosphate enema) can be administered through the scope to
induce evacuation. The fluid is filtered so that the polyps
can be recovered for histologic examination. - PITFALL: Suspected perforation after
polypectomy necessitates hospital observation and
evaluation.
Step 12 View Original Step 12 View Original
Complications
- Perforation: 1 to 2 per
1,000 procedures (studies from diagnostic colonoscopies only,
however) - Bleeding following
polypectomy - Adverse reaction from
sedatives such as respiratory depression, allergic reaction, or
cardiac dysrhythmia
Pediatric Considerations
Pediatric endoscopes are available,
which have a narrower diameter than adult endoscopes.
Postprocedure Instructions
Patients are usually monitored for 30
minutes after the procedure to make sure that they have recovered
completely from sedation. Someone must drive them home, but they can
resume a regular diet right away. They should be warned to contact their
provider immediately if they experience severe abdominal pain (not just
gas cramps); a firm, distended abdomen; vomiting; fever; or bleeding
greater than a few tablespoons.
Coding Information and Supply Sources
Current Procedural Terminology (CPT)
codes listed here include the terminology "proximal to the
splenic flexure " in the code descriptor. However, for reporting
purposes, colonoscopy is the examination of the entire colon from the
rectum to the cecum and may include examination of the terminal ileum.
For an incomplete colonoscopy, with full preparation administered with
the intent to perform a full colonoscopy, use the colonoscopy codes
above with a -52 modifier to signify reduced services. In the office
setting, a tray charge can be billed (99070 or A4550) to help cover
procedure costs.
View Large CPT Code Description 2008 AVERAGE 50th Percentile Fee Global Period 45378 Flexible colonoscopy with brushing, washing $1,041.00 0 45379 Flexible colonoscopy with removal of foreign body $1,238.00 0 45380 Flexible colonoscopy with one or more biopsies $1,143.00 0 45382 Flexible colonoscopy with bleeding control by
coagulator $1,371.00 0 45383 Flexible colonoscopy with ablation of tumors or polyps $1,389.00 0 45384 Flexible colonoscopy with tumor or polyp removal by hot
biopsy forceps $1,358.00 0 45385 Flexible colonoscopy with tumor or polyp removal by snare
technique $1,491.00 0 CPT is a registered trademark of the American
Medical Association.2008 average 50th Percentile Fees are provided courtesy of 2008
MMH-SI 's copyrighted Physicians ' Fees and
Coding Guide.
Common ICD-9 Codes
View Large Abdominal mass 789.3 Anemia, unexplained 280.9 Iron deficiency anemia secondary to blood loss,
anemia 280.0 GI bleeding, acute 578.9 GI bleeding, occult 578.1 X-ray abnormality 793.4 Weight loss, severe 783.2 Benign neoplasm colon 211.3 Constipation, slow transit 564.01 Constipation, outlet dysfunction 564.02 Diverticulosis with blood 562.12 Rectal bleeding 569.3 Personal Hx CRCa V10.05 Family Hx CRCa V16.0 Ulcerative colitis 556.9 Rectal pain 569.42 Change in bowel habits 787.99 Personal Hx colon polyps V12.72 Abdominal mass 789.3 Anemia, unexplained 280.9 GI bleeding, acute 578.9 GI bleeding, occult 578.1 X-ray abnormality 793.4 Weight loss, severe 783.2
Instrument and Materials Ordering
- Recommendations
for endoscope cleaning appear in Appendix
K: Recommendations for Endoscope
Disinfection - Complete
endoscopy equipment such as endoscopes, light sources, video
endoscopy monitors, cleaning and disinfection aids, and
mouthpieces are available from the following
manufacturers: Olympus
Corporation, Center Valley, PA (http://www.olympusamerica.com)
Pentax Precision
Instrument Corporation, Montvale, NJ (http://www.pentaxmedical.com)
- Intravenous
materials (e.g., intracaths, normal saline solution,
intravenous tubing) can be obtained from local hospitals or
surgical supply houses. - Propofol (1% Diprivan) injection
is available from AstraZeneca, Wilmington, DE
(http://www.astrazeneca-us.com). Meperidine (Demerol) injection is
available from Wyeth-Lederle (http://www.wyeth.com). Midazolam (Versed)
injection is available from Roche, Nutley, NJ (http://www.roche.com). - Guidelines for
monitoring patients receiving conscious sedation appear in Procedural (Conscious)
Sedation.
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