Colonoscopy

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A colonoscopy (also colonoscopy or colonoscopy ) is used to examine the colon and usually the last centimeter of the small intestine .

Model representation of a colonoscopy

A pioneer in this field was the Swiss Peter Deyhle (1969).

indication

The reasons (indication) for performing a colonoscopy are:

Alternatives

Before a colonoscopy is advised by the attending physician or gastroenterologist , a detailed anamnesis of family history and appetite behavior , weight loss without dietary exertion , pain , nausea , vomiting , gas or bowel movements , if an intestinal disease is suspected , is recommended can be changed.

By listening to the abdomen, intestinal noises are recognized, which can provide information about bowel function. The palpation of possible resistances (e.g. tumors), tapping ( percussion ) and the inspection of the abdomen also serve as a further possibility to assess the gastrointestinal tract for changes. The rectal examination can also contribute to an alternative examination, whereby the mucous membrane conditions and lower intestinal sections can be assessed.

The stool examination by means of a rapid test for occult (invisible) blood in the stool counts as well as the colonoscopy for colorectal cancer screening. The test is recommended annually for men and women from the age of 50 according to guidelines, the health insurance companies pay the test from the age of 50. Regular attendance is important to increase the chance of an early diagnosis of a positive test result. Such a positive test result (i.e. blood in the stool) is an indication for a colonoscopy. However, a negative test result is no more reliable criterion for ruling out colon cancer . The Federal Joint Committee (G-BA) decided in April 2016 that new test procedures will be used in the future for the early detection of colon cancer. Quantitative immunological tests for the detection of invisible blood in stool ( iFOBT ) are replacing the gujak -based test (gFOBT) currently in use . The iFOBT is said to reveal a disease with a 5% higher probability.

The colonic enema , which can show the colon and rectum using conventional X-rays , is increasingly being replaced by virtual colonoscopy , as it can more reliably detect tumors and other changes. Other imaging methods are expected to play a greater role in the future, such as B. Colon capsule endoscopy. Using a video camera, a non-invasive, very precise representation of the intestine can be carried out faster and without great preparation and stress for the patient.

preparation

Before the examination, the large intestine must be emptied so that the examination is not obstructed by stool remains. For this purpose, a strong laxative is administered the day before or occasionally a few hours before the examination, usually in the form of an orthograde intestinal lavage , less often as an enema . Many patients find purging with a PEG purging solution stressful and uncomfortable. A few years ago, 3 to 5 liters of poorly tasting liquid had to be drunk within a few hours. The unpleasant taste can be alleviated by cooling the solution or mixing it with clear apple juice. There are also lemon or orange flavored 2 liter supplements on the market designed to make the process easier. Those who cannot or do not want to drink the laxative can also receive the solution through a gastric tube . There is also the option of using a combination of osmotic, motility and secretion-influencing laxatives to cleanse the bowel. The patient has to drink a lot (tea, water, etc.), but drinking is usually easier for him. The disadvantage of this method is that electrolyte shifts in the body's water and mineral balance occur more frequently, the circulatory load can be higher and the intestine is not quite as clean.

device

Variable flexibility colonoscope

The flexible colonoscope has a diameter of about 1 cm and a length of about 1.2 meters. A video colonoscope is mostly used today, which has a video chip at the tip and transmits the image to a monitor. This makes it possible for the patient to follow the examination. The colonoscope is equipped with a suction device to suck up liquid stool residues and irrigation fluid. A working channel enables the introduction of small instruments (forceps and loops) with which small tissue samples or polyps can be removed.

Sedation and monitoring

The colonoscopy is performed by a doctor in either a practice or a clinic. You can use a sedative, e.g. B. Midazolam , if necessary in conjunction with a pain reliever such as pethidine or tramadol , to make the examination more pleasant. In the meantime, the examination is also carried out under short anesthesia , usually with the anesthetic propofol , so that the patients do not notice anything of the entire procedure. However, it should be noted that sedation or short anesthesia is responsible for at least 50% of the complications that occur during the examination. In particular, it is the major cause of cardiopulmonary (i.e., cardiovascular and respiratory) complications, which are the leading cause of colonoscopy-related death.

The advancement of the device can lead to tension on the hanging straps of the colon (large intestine). This can cause pain. However, this pain is associated with the above. Medicines completely suppressible so that no patient has to suffer from the examination anymore. If the patient wants to stay awake for the time being and follow the examination on the monitor, there is always the option of having sedation or short anesthesia in the event of complaints.

The patient is continuously monitored during sedation. Usually, a probe is attached to the patient's finger to measure oxygen saturation and pulse ( pulse oximetry ). In the case of high-risk patients, the blood pressure may also be measured several times.

Investigation process

At the beginning of the examination, the patient lies on his back. While the sedation or anesthesia may begin to take effect, the patient is brought into a stable left-sided position with the legs slightly bent. The instrument is advanced under sight with straightening or repositioning maneuvers until the appendix (caecum) or the last part of the small intestine (terminal ileum ) is reached. When the colonoscope is withdrawn, the intestine is unfolded by means of air insufflation (air injection) and the entire intestinal mucosa is carefully searched for pathological changes. The exam usually takes about 25 minutes. The volume of air of a few liters blown in for intestinal unfolding can briefly cause intestinal flatulence (so-called "winds") during and after the examination , but these usually disappear again quickly. Using CO 2 instead of room air can minimize the problem as CO 2 is absorbed by the intestinal mucosa up to 150 times faster.

Findings

  • Normal large intestine (transverse colon)

  • Normal appendix with Bauhinscher valve (ascending colon)

  • Sigma diverticulum

  • Pedunculated colon polyp

  • Circular colon cancer

  • Inflammatory colon stenosis

  • Angiodysplasia in the appendix

therapy

Diverticulum

Diverticula do not require any therapy and should not be regarded as a disease. Only in the case of bleeding from diverticula is hemostasis endoscopically possible in very rare cases. Diverticulitis can also be diagnosed, although colonoscopy is not advisable during the inflammatory phase because of possible perforation of the inflamed and thus more easily injured intestinal wall.

Polyps

Polyps are macroscopically visible, mostly pedunculated protuberances of the mucosa. Over the course of several years, they can degenerate and lead to colon cancer (see also adenoma-carcinoma sequence ), and they are therefore removed in the same session (also as part of screening colonoscopies).

Inflammation / ulcer

For a more precise differentiation of inflammatory changes and ulcers, samples are taken from the mucous membrane with forceps pushed through the endoscope ( biopsy ) and / or secretions are obtained specifically for bacteriological examination.

Tumors

Biopsy of a suspected tumor area

In the case of tumors and especially colon cancer ( colon cancer ), tissue samples are taken for a precise fine-tissue examination . In patients who are no longer operable, a stent can be inserted endoscopically in the event of severe constriction in order to enable the passage of the faeces and to avoid an artificial anus ( anus praeter ). In a large-scale study in Saarland , it was shown that people who had undergone preventive colonoscopy ( cancer screening ) within the last ten years had significantly less frequent advanced cancer than those in a comparison group who underwent colonoscopy for the first time (6.1% to 11.4%).

Stenoses

In the case of constrictions, a balloon can be inserted through the endoscope which, after filling with air or water, expands the constriction ( balloon dilatation ). However, this therapy is reserved for specialists only, as there is a risk of intestinal rupture ( perforation ).

Bleeding

Bleeding occurs when:

Bleeding can be stopped endoscopically with the injection of medication or with heat ( coagulation ).

Complications

Nowadays, colonoscopy is considered a routine examination and is therefore particularly safe and low-risk. Nevertheless, complications with adverse health consequences for the patient can occur.

Possible complications are perforations (damage to the intestinal wall) that can occur through the endoscope or by blowing in air. This can lead to the transfer of intestinal contents and bacteria into the abdominal cavity, which can make an operation necessary in the further course. Bleeding and secondary bleeding of the intestinal wall, which can result from the removal of polyps (swelling of the mucous membrane) and / or tissue, cannot be ruled out. In most cases, these can already be satisfied during the colonoscopy by injections, the attachment of hemoclips or other procedures. A sepsis can (blood poisoning) as a result of Einschwemmung of intestinal bacteria occur in the bloodstream and the administration of antibiotics make necessary. Too high a dose of tranquilizers or an allergic reaction to the medication administered can lead to disorders of the respiratory and cardiovascular functions and even cardiac arrest.

The risk of most complications is higher in elderly patients (with serious comorbidities) than in younger patients. Complications may also arise if the colonoscopy is performed by an inexperienced doctor.

Use as a preventive medical check-up

A colonoscopy or colonoscopy can be used in Germany as a preventive medical examination from the age of 50 in the statutory health insurance . A second examination can be carried out every ten years.

The benefit of a preventive medical check- up has to be weighed up between its actual effectiveness and possible negative consequences such as complications. Like other preventive measures, colonoscopy has the potential to overdiagnose. The examination reveals and treats pathological changes that might not have impaired the life expectancy and quality of life of a person even without treatment.

As a preventive measure, patients without specific symptoms are given a colonoscopy. Accordingly, most patients will not be diagnosed with pre-existing colon cancer. In contrast, 114 out of 1,000 patients who had not previously received a colonoscopy were diagnosed with adenomas (polyps). These can develop into colorectal cancer, the malignant colon cancer. Complications involving the digestive tract or the cardiovascular system occur in 35 out of 10,000 examinations. However, further complications may arise in the days following the examination.

The reliability of the colonoscopy is high. About 97% of the existing adenomas , possible precursors of a carcinoma , are recognized. However, the quality also depends on the experience of the examiner. In order to be able to settle an outpatient colonoscopy with the statutory health insurance, a doctor in Germany must therefore prove 200 examinations and 10 polyp removals per year.

A long-term study from the USA with a follow-up period of up to 23 years found a 53% reduction in colon cancer mortality in people who had a colonoscopy with removal of colon polyps. The colonoscopy group was not compared with a real, untreated group, but with a statistically expected mortality rate; after an average of 15 years of observation, 12 of 2602 patients (0.5%) had died from colon cancer instead of the statistically expected 25 patients (1%). Around 48% of the patients died of other causes during the follow-up period. For every 195th colonoscopy performed, one death from colon cancer could be prevented. However, the extent to which the preventive medical check-up increases life expectancy is unknown. Further studies that can make more precise statements about the effects of the colonoscopy as a general preventive examination are currently being carried out in Northern Europe, Spain and the USA. However, results will not be available until 2021. A case-control study that was published in the Annals of Internal Medicine in 2013 found that a preventive colonoscopy could reduce the incidence of colon cancer by more than two thirds. The results are therefore similar to a German study from 2011.

See also

Oral access (sorted by depth of penetration):

Anal access (sorted by depth of penetration):

Individual evidence

  1. ↑ a b A. Bürger-Mildenberger, N. Menche, J. Willert: Care for diseases of the gastrointestinal tract. In: N. Menche, T. Klare (Ed.): Internal medicine. Textbook for nursing professions. 4th edition. Elsevier GmbH, Munich 2005. pp. 318-319
  2. ↑ "Guideline of the Federal Joint Committee on Organized Cancer Early Detection Programs" (PDF; 316 kB)
  3. ↑ Colon cancer screening will be based on a new test procedure , PM G-BA dated April 21, 2016, accessed on April 26, 2016
  4. ↑ a b Graser et al .: Comparison of CT colonography, colonoscopy, sigmoidoscopy and faecal occult blood tests for the detection of advanced adenoma in an average risk population. In: Gut 58 (2), 2009. pp. 241–248 doi: 10.1136 / gut.2008.156448
  5. ↑ "National Cancer Plan" ( memento of the original from March 6, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 270 kB). Field of action 1: Objectives paper 2 b. Further development of colorectal cancer early detection (including development of organized colorectal cancer screening) @1@ 2Template: Webachiv / IABot / www.bmg.bund.de
  6. ↑ H.-J. Schulz: The Colon Capsule - A Method Looking For A Problem? 34th German Coloproctologist Congress. Munich, 6.-9. March 2008 doi: 10.1007 / s00053-008-8030-9
  7. ↑ A. Riphaus et al .: S3 guideline "Sedation in gastrointestinal endoscopy". 2015. PDF section 4.1.4.
  8. ↑ Guido Schachschal: Practical Colonoscopy. Stuttgart 2010. p. 17.
  9. ↑ Documented for the first time across the population: colonoscopy protects against cancer - possibly even a small colonoscopy of great benefit. (PDF; 40 kB) Press release of the DKFZ from January 4, 2010
  10. ↑ Federal Ministry of Health: "Effectiveness and efficiency of CT colonoscopy in comparison to conventional colonoscopy in colon cancer diagnosis and early detection" (2009; PDF; 936 kB)
  11. ↑ Rabeneck et al. (2008): Bleeding and Perforation After Outpatient Colonoscopy and Their Risk Factors in Usual Clinical Practice, In: Gastroenterology 135 (6), 1899-1906. doi: 10.1053 / j.gastro.2008.08.058
  12. ^ "Guideline of the Federal Joint Committee on Organized Cancer Early Detection Programs." (PDF; 316 kB)
  13. ↑ Brenner et al. (2010): Protection From Right- and Left-Sided Colorectal Neoplasms After Colonoscopy: Population-Based Study. In: Journal of the National Cancer Institute 102 (2), 89-95. doi: 10.1093 / jnci / djp436
  14. ↑ Crispin et al. (2008): Process quality and incidence of acute complications in a series of more than 230,000 outpatient colonoscopies. In: Endoscopy 41 (12), 1018-1025. doi: 10.1055 / s-0029-1215214
  15. ↑ Warren et al. (2009): Adverse Events After Outpatient Colonoscopy in the Medicare Population. In: Annals of Internal Medicine 150 (12), 849-857
  16. ↑ Requirements according to § 135 Abs. 2 SGB V for the execution and billing of colonoscopic services ( "Quality Assurance Agreement for Colonoscopy" ) from June 15, 2012.
  17. ^ AG Zauber, SJ Winawer, MJ O'Brien, I. Lansdorp-Vogelaar, M. van Ballegooijen, BF Hankey, W. Shi, JH Bond, M. Schapiro, JF Panish, ET Stewart, JD Waye: Colonoscopic polypectomy and long -term prevention of colorectal cancer deaths. In: The New England Journal of Medicine . Volume 366, Number 8, February 2012, pp. 687-696, doi : 10.1056 / NEJMoa1100370 , PMID 22356322 , PMC 3322371 (free full text).
  18. ^ ClinicalTrials.gov
  19. ^ ClinicalTrials.gov
  20. ^ ClinicalTrials.gov
  21. ↑ CA Doubeni, S. Weinmann, K. Adams, A. Kamineni, DS Buist, AS Ash, CM Rutter, VP Doria-Rose, DA Corley, RT Greenlee, J. Chubak, A. Williams, AR Kroll-Desrosiers, E Johnson, J. Webster, K. Richert-Boe, TR Levin, RH Fletcher, NS Weiss: Screening colonoscopy and risk for incident late-stage colorectal cancer diagnosis in average-risk adults: a nested case-control study. In: Annals of internal medicine. Volume 158, Number 5 Pt 1, March 2013, pp. 312-320. doi : 10.7326 / 0003-4819-158-5-201303050-00003 . PMID 23460054 .
  22. ^ H. Brenner, J. Chang-Claude, CM Seiler, A. Rickert, M. Hoffmeister: Protection from colorectal cancer after colonoscopy: a population-based, case-control study. In: Annals of internal medicine. Volume 154, Number 1, January 2011, pp. 22-30. doi : 10.7326 / 0003-4819-154-1-201101040-00004 . PMID 21200035 .

Web links

Wiktionary: Colonoscopy  - explanations of meanings, word origins, synonyms, translations