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Colonoscopy: history and development.

Retrograde colonoscopy of the entire colon, and endoscopic excision of polyps from anywhere in the colon, began in June and September of 1969, respectively. Momentous advances have occurred over the past two decades, and the two procedures are now widely accepted and practiced. Development and perfection of the methodology were, at first, fraught with many difficulties, both procedural and technical, which had to be overcome. Significant opposition was engendered in the early years by some who claimed that the methods were both unnecessary and unduly dangerous. Time has proven otherwise. Progress came about as the result of a steady stream of publications from a number of centers documenting the successful and safe application of the methodology. A recounting is presented of the many contributions that predated development of the colonoscope and colonoscopy, and how the latter came about. For those coming into the art more recently, this review of beginnings is offered to allow a balanced evaluation of their craft.

Colonic Polyps↗

Treatment of colonic polyps--practical considerations.

The adenomatous colonic polyp, a neoplastic lesion, is the precursor of most if not all carcinomas of the colon and rectum. Confirmatory evidence is derived from epidemiological, histological and clinical data demonstrating a close parallelism between adenomas and cancer of the colon. Based on current knowledge, all colonic polyps should be removed to prevent the development of colonic cancer. However, since the risk of malignancy within an adenoma is related to its size, histology and the degree of dysplasia, practical considerations dictate that all polyps 1 cm in diameter or larger should be removed upon their detection by barium enema or colonoscopy since such adenomas are the ones most likely to contain malignancy. The endoscopic removal of colon polyps can be efficiently and safely accomplished when established principles of colonoscopy and electrosurgery are followed. This technique requires the proper equipment, a skilled endoscopy assistant, and an experienced endoscopist with the ability to adeptly perform colonoscopy, an understanding of the basic concepts of electrocautery and knowledge of the various structural configurations of colonic polyps. Colonoscopic polypectomy will avoid the need for surgical resection in most instances. Management of the malignant colonic polyp remains controversial. The patient with a sessile or pseudo-pedunculated polyp containing invasive cancer should undergo colonic resection. Surgery is not necessary for the majority of patients whose pedunculated adenomas contain invasive cancer, unless the malignancy is poorly differentiated, the cancer invades lymphatics or vascular channels, or tumour is seen at or near the resection margin. Surveillance colonoscopy after endoscopic polypectomy should be performed in most instances within one year to look for recurrent tumour, missed polyps or a metachronous adenoma. Subsequently, colonoscopy should be performed every two years in patients with multiple index polyps, and every three years after removal of a single index adenoma.

Adenoma↗

Evaluation of colonic neoplasia by flow cytometry of endoscopic biopsies.

Colonoscopy is a valuable and frequently used method in the evaluation of colonic neoplasia. Flow cytometry is a technique that can be used to diagnose malignancy. In this study, flow cytometry was used to evaluate colonoscopic biopsies taken from patients with suspected colonic neoplasia. Nineteen colonic biopsies were obtained and evaluated by this technique. Aneuploidy was demonstrated in six patients with carcinoma of the colon. In addition, abnormal DNA histograms were noted in two premalignant conditions (colonic adenoma and inflammatory bowel disease). The results show that flow cytometry can be applied to colonic biopsies and suggest that it may be of use in the diagnosis of malignant and premalignant conditions of the colon.

Adenoma↗

Colonoscopy in childhood.

A review was made of 139 fiberoptic colonoscopies performed between 1975 and 1982 on 113 patients aged 1 month to 20 years. General anesthesia was used in four procedures. All others were done under sedation with meperidine (mean dose 2.9 mg/kg) and diazepam (mean dose 0.5 mg/kg). Indications were rectal bleeding in 52 patients; assessment and surveillance of known inflammatory bowel disease in 33 patients; and diagnostic evaluation of abdominal pain, diarrhea, and/or fever in 28 patients. The cecum was reached in 84% of diagnostic examinations. Comparison of findings on colonoscopy with barium enema in 75 patients showed agreement in 46, colonoscopic superiority in 25, and barium enema superiority in four. Bleeding sufficient to cause anemia was seen in 10/26 patients with polyps. Five minor complications and no major complications occurred. Flexible fiberoptic colonoscopy and polypectomy may be done usefully in childhood by physicians well versed and experienced with these procedures. Colonoscopy and biopsy changed the radiographic diagnosis from ulcerative colitis to Crohn's disease in several cases and indicated greater extent of colonic disease in several cases of ulcerative colitis and Crohn's disease. Colonoscopy is usually the most sensitive and accurate diagnostic tool for the evaluation of colonic disease, but barium enema and colonoscopy are complementary tests and barium enema should usually precede colonoscopy, with certain exceptions.

Adolescent↗

Total colonoscopy in children.

One hundred and twenty-three total colonoscopies were performed on 115 children with ages ranging from 3 months to 16 years. The major indications were suspected inflammatory bowel disease and unexplained rectal bleeding. Ninety-seven per cent of all procedures were carried out with sedation only. Adult colonoscopes were used in most of the patients but in babies and small children paediatric instruments were preferable. Total colonoscopy was possible in all patients with a patent colon. The terminal ileum was examined in 63 patients. Endoscopic snare polypectomy was successfully carried out in 8 children and multiple haemangiomas were electrocoagulated in one. Total colonoscopy in this paediatric series proved to be at least as easy, rapid, well-tolerated, and safe as in adults. In selected patients as single colonoscopy can give an accurate diagnosis with biopsy proof and sometimes the opportunity for definitive treatment.

Adolescent↗

Liquid chemical sterilization using peracetic acid. An alternative approach to endoscope processing.

Recurrent episodes of endoscope contamination with nontuberculous mycobacterium and Pseudomonas species, coupled with employee concerns about exposure to 2% glutaraldehyde and the requirement for rapid scope turnover time, led to the investigation of an alternative method for endoscope processing. A prospective evaluation of 220 bronchoscopy procedures was carried out. Endoscope culture surveillance was performed twice a month for a 12 month period on all endoscopes. In addition, the deliberate inoculation of bronchoscopes with Mycobacterium gordonae was carried out. No indications of cross contamination were noted among the 220 bronchoscopy procedures after processing the scopes by the studied liquid chemical sterilization system using peracetic acid. Ongoing patient surveillance did not reveal any indications of cross contamination for nearly 15,000 patients diagnostic or surgical endoscopic procedures using instruments processed by this liquid chemical sterilization system. Twice a month for 12 months, bronchoscopes, colonoscopes, and gastroscopes were cultured for bacterium, fungi, and acid fast bacilli and showed no growth. Deliberate inoculation of bronchoscopes with M. gordonae showed the scopes were rendered sterile. No unusual occurrences of occupational chemical exposure were found in 11 individuals working with this liquid chemical sterilization system. The peracetic acid based sterilization system studied proved to be an effective, safe, and economical alternative to the glutaraldehyde method.

Adolescent↗

Technically difficult colonoscopy, a non-radiologic sign of sigmoidal obstruction: value of sigmoid colectomy for intractable symptoms.

Technical difficulty in passing the colonoscope was assessed in 371 patients undergoing 627 colonoscopies during 1989-91 and were graded as 0: no difficulty and cecum reached (71.43%); 1: difficult but cecum reached (20.22%); 2: difficult and cecum not reached although lumen beyond seen (4.85%); and 3: difficult and cecum not reached as lumen beyond could not be seen (3.5%). Frequency of patients with chronic lower abdominal pain and/or disturbed bowel habits in each grade increased as grade of obstruction increased: 0 (25.66%), 1 (36%), 2 (77.77%), and 3 (100%). During 1983-91, 54 patients with lower abdominal pain and/or disturbed bowel habits for a mean of 30.5 months, unresponsive to conventional medical measures, and who also had a grade 2 or 3 sigmoidal obstruction, elected to undergo sigmoid colectomy. Operative and pathologic studies showed that the primary cause was fixation of the sigmoid colon to the pelvis in two or three loops by adhesions from previous pelvic surgery, endometriosis, ovarian cyst, or diverticulitis. All patients had relief of symptoms that was maintained during the 1-9 year follow-up.

Abdominal Pain↗

Quantitative standardised analysis of advanced laparoscopic surgical procedures.

To support the improvement of advanced laparoscopic surgical procedures, we designed a quantitative analysis method to monitor surgical activities. The emphasis lies on the time spent on these activities and on the instruments controlled by the hands of the surgeon. Our method uses combined video images originating from the laparoscope, an overview CCD camera placed in the operating theatre and, when available, a video colonoscope. After the operation is finished, the images are evaluated by means of a standardised analysis routine based on a spreadsheet program and a set of standard terms (thesaurus), to minimise subjectivity of the analysis. After calculations, the data are presented in tables and graphs, resulting in objective information for research on the operation. Seven advanced laparoscopic procedures, in this case colon resections, have been analysed, and it was demonstrated that the analysis method is capable of describing different laparoscopic procedures using the limited thesaurus. Possible areas of application of the method are the evaluation of time-consuming parts of the operation, of surgical tasks and measurement of the surgeon's learning curve. Other applications are the prediction and measurement of the impact of new instruments and techniques.

Colectomy↗

Peroral colonoscopy. Technique, depth, and yield of lesions.

Examination of portions of the small bowel beyond the reach of standard upper endoscopes can be done using peroral passage of a colonoscope. Important information can be obtained and directed biopsies and treatment of bleeding lesions can be performed.

Biopsy↗

New methods of polypectomy.

The three most prominent advances in colonoscopic polypectomy are the submucosal injection of saline to ensure safety of polypectomy, the use of the small, or mini, snare for removal of most colon polyps, and the introduction of the argon plasma coagulator for the treatment of vascular abnormalities of the colon and the fulguration of residual adenoma at the base of sessile polyps with a noncontact technique. The role of Endoloop, endoscopic clips, and rubber band ligation for polypectomy is discussed.

Argon↗

[Virtual CT colonoscopy. Examination technique, limitations and perspectives].

Virtual CT-colonoscopy is a post-processing method which allows for reconstruction of inner bowel surface structures from helical CT datasets. The reconstructed images simulate the views which are known from fiberoptic endoscopy. Since colorectal cancer is the second main cause of death in USA and Europe today and since recent screening recommendations are often ignored by the public, a non-invasive or minimal-invasive procedure for colonic evaluation would offer some benefits. Virtual CT-colonoscopy generally involves three essential steps: patient preparation with cleansing of the bowel and administration of an air enema, helical CT-examination by using appropriate scan parameters, and interactive 3D rendering of the volume data-set. Although recent studies have demonstrated that polypoid lesions of about 5 mm size are well detectable and although virtual colonoscopy offers many advantages over fiberoptic endoscopy, some technical and clinical limitations must still be noted. Thus, the current inability of virtual colonoscopy to provide texture and color leads to problems in identifying flat lesions; the presence of retained or adherent fecal matter may result to false positive diagnosis and collapsed segments of bowel may cause problems as they cannot subsequently be evaluated during image reconstruction. Virtual endoscopy is still in its infancy and further technical and clinical developments are necessary. Virtual CT-colonoscopy may then prove to be equal or superior to colonoscopy in sensitivity and specificity for polyp detection and be able to reduce the number of unnecessary colonoscopic procedures.

Colonoscopes↗

Localizing colorectal cancer by colonoscopy.

HYPOTHESIS: Colonoscopic localization of colorectal carcinoma is frequently inaccurate and unreliable. DESIGN: Consecutive case series. SETTING: Tertiary care teaching hospital. PATIENTS: Three hundred fourteen consecutive patients undergoing surgical resection for colorectal cancer from January 1, 2000, to December 31, 2003. INTERVENTION: Surgical resection for colorectal cancer. MAIN OUTCOME MEASURE: Incidence of erroneous site localization. RESULTS: Two hundred thirty-six patients had complete endoscopic, pathologic, and operative records. Colonoscopy was inaccurate for tumor localization in 49 cases (21%). In 27 (11%) of these cases, a different procedure was required than initially planned; in an additional 10 cases (4%), the surgical approach required modification. Inaccurate localization was associated with previous colorectal procedures on both univariate analysis (odds ratio, 3.94; 95% confidence interval, 1.50-10.32; P<.005) and multivariate analysis (odds ratio, 4.47; 95% confidence interval, 1.64-12.08; P = .003). Having the colonoscopy performed by a surgeon trended toward protection from error on multivariate analysis (odds ratio, 0.47; 95% confidence interval, 0.20-1.08; P = .07). Age, sex, diverticular disease, endoscopist volume and years of training, and bowel preparation had no significant effect. CONCLUSIONS: Colonoscopy has a considerable error rate for localization of colorectal cancer, especially when previous colorectal procedures have been performed. Adjunctive localizing techniques, such as endoscopic tattooing, should be strongly considered.

Adult↗

Diagnostic and therapeutic colonoscopy. A critical review of 662 examinations.

The results of 662 therapeutic and diagnostic colonoscopic examinations were reviewed to assess the morbidity, clinical benefit, diagnostic accuracy, and indications for the procedure, with special emphasis on detection and endoscopic excision of small, occult, invasive cancers. Overall, the frequency of detecting occult lesions (19%), the (89%) ability to clarify questionable radiographic findings, and a substantial reduction in laparotomy-colotomy procedures required for removal of colonic polyps (88%), coupled with a low morbidity (3%) and low false-negative examination rate (1%) established colonoscopy as one of the most important advances in the management of colon disease in recent years. Although early experience suggests that small, occult, invasive carcinomas, when properly selected, could be adequately treated by endoscopic excision, larger series and longer follow-up periods are necessary to validate any conclusions regarding the decision to manage these lesions conservatively.

Carcinoid Tumor↗

Diagnosis and management of nonspecific colon ulcer.

This report describes seven cases of nonspecific colon ulcers and analysis of the additional 120 cases reported in the literature through 1980. The total current series is compared with the two earlier reviews. Our findings showed that nonspecific colon ulcers occur in all age groups, predominantly 40 to 60 years, with slight predilection to female sex. The man clinical manifestations include abdominal pain mimicking appendicitis (50%), lower gastrointestinal hemorrhage (33%), perforation (19%), and abdominal mass (16%). The usual location of the ulcers is the cecum and ascending colon (67%), then transverse, hepatic, and splenic flexures (18%), and descending and sigmoid colon (15%). The diagnosis is best established by colonoscopy. The nonoperative conservative management is probably indicated in the uncomplicated cases with follow-up colonoscopic studies to ensure complete healing. The etiology of this condition is still unknown.

Adult↗

Colonoscopy after curative resection of colorectal cancer.

Colonoscopy is generally considered to be an important part of the follow-up program for patients who have undergone curative resection of colorectal cancer. However, there are few data available concerning the frequency with which colonoscopy should be performed and for what length of time after operation. Since 1978, our policy has been to examine the colon annually in these patients using colonoscopy alternating with barium enema. We have evaluated the results in 100 patients over a four-year period. Based on size and histology, the significant colonoscopic findings were new colon cancers in three patients and 11 polyps demonstrating increased risk for malignancy in nine patients. This represents an interval yield of 3% per year. From these results and other reports, we recommend that these patients undergo total colonoscopy in the perioperative period to identify and remove synchronous lesions of the colon, and that examination of the remaining colon should be performed annually, preferably with colonoscopy, for at least the first four years after curative resection.

Barium Sulfate↗

Lower gastrointestinal hemorrhage in renal transplant recipients.

A review of the literature and our own series revealed 38 patients with lower gastrointestinal (LGI) hemorrhage among 4086 renal transplant recipients (0.9%). These patients represent 30% of 128 patients with major colorectal complications in this group. Of the 32 patients whose treatment and outcome were reported, only 12 (38%) were treated operatively. The overall mortality rate was 72%. The causes of LGI hemorrhage included colitis from opportunistic infections (42%); pseudomembranous, ischemic, or uremic colitis (40%); and idiopathic ulcers of the colon (18%). Colonoscopic, gross, and histopathologic findings of a patient with massive LGI hemorrhage from a fungal ulcer of the colon are the focus of this study, as are the implications of such findings. We propose an algorithm for diagnostic and therapeutic management decisions. We emphasize prompt diagnosis and the importance of colonoscopy. We propose withdrawal of immunosuppression and early operative intervention if the patient survival rate is to improve.

Candidiasis↗

Retrospective review of colorectal cancer in ulcerative colitis at a tertiary center.

OBJECTIVE: To review patient characteristics, surgical indications, operative procedures, and survival of patients with ulcerative colitis who develop colorectal cancer. DESIGN: Retrospective medical record review. SETTING: Tertiary referral center. PATIENTS: Of 493 patients who underwent surgery for ulcerative colitis between 1978 and 1994, 25 patients had colorectal cancer. INTERVENTION: All patients underwent surgical exploration and either a biopsy, segmental resection, total abdominal colectomy, or restorative proctocolectomy was performed. MAIN OUTCOME MEASURE: Duration of postoperative disease-free survival. RESULTS: The average duration of illness prior to surgery was 18.5 years (range, 0.25-40 years). Surgical indications were intractability for 3 patients (12%); dysplasia as revealed by colonoscopic biopsy for 8 patients (32%); and preoperatively diagnosed cancer for 14 patients (56%). Three patients (12%) underwent exploratory laparotomy, 3 (12%) underwent right hemicolectomy, 5 (20%) underwent total proctocolectomy with ileostomy, 3 (12%) underwent total proctocolectomy with continent ileostomy, and 12 (48%) underwent restorative proctocolectomy. Pathological stage was carcinoma in situ for 3 patients (12%), stage I for 7 patients (28%), stage II for 4 patients (16%), stage III for 6 patients (25%), and stage IV for 5 patients (20%). Five-year survival was 100% (3/3) for patients with carcinoma in situ, 100% (4/4) for those with stage I disease, 50% (2/4) for those with stage II, 25% (1/4) for those with stage III, and 0% (0/5) for those with stage IV. Of the 12 patients treated with a restorative proctocolectomy, 6 are 5-year survivors, and 4 are alive at 24, 36, 38, and 48 months. CONCLUSIONS: Twelve percent of the patients in this series had no preoperative evidence of colorectal malignant neoplasms but had invasive cancer in the resected specimen. Therefore, duration of disease alone may be an indication for surgery. A restorative proctocolectomy is a satisfactory procedure in selected patients with malignant neoplasms.

Adult↗

Recommendations for the care of individuals with an inherited predisposition to Lynch syndrome: a systematic review.

CONTEXT: About 2% of all colorectal cancer occurs in the context of the autosomal dominantly inherited Lynch syndrome, which is due to mutations in mismatch repair genes. Potential risk-reducing interventions are recommended for individuals known to have these mutations. OBJECTIVES: To review cancer risks and data on screening efficacy in the context of Lynch syndrome (hereditary nonpolyposis colorectal cancer) and to provide recommendations for clinical management for affected families, based on available evidence and expert opinion. DATA SOURCES AND STUDY SELECTION: A systematic literature search using PubMed and the Cochrane Database of Systematic Reviews, reference list review of retrieved articles, manual searches of relevant articles, and direct communication with other researchers in the field. Search terms included hereditary non-polyposis colon cancer, Lynch syndrome, microsatellite instability, mismatch repair genes, and terms related to the biology of Lynch syndrome. Only peer-reviewed, full-text, English-language articles concerning human subjects published between January 1, 1996, and February 2006 were included. The US Preventive Services Task Force's 2-tier system was adapted to describe the quality of evidence and to assign strength to the recommendations for each guideline. EVIDENCE SYNTHESIS: The evidence supports colonoscopic surveillance for individuals with Lynch syndrome, although the optimal age at initiation and frequency of examinations is unresolved. Colonoscopy is recommended every 1 to 2 years starting at ages 20 to 25 years (age 30 years for those with MSH6 mutations), or 10 years younger than the youngest age of the person diagnosed in the family. While fully acknowledging absence of demonstrated efficacy, the following are also recommended annually: endometrial sampling and transvaginal ultrasound of the uterus and ovaries (ages 30-35 years); urinalysis with cytology (ages 25-35 years); history, examination, review of systems, education and genetic counseling regarding Lynch syndrome (age 21 years). Regular colonoscopy was favored for at-risk persons without colorectal neoplasia. For individuals who will undergo surgical resection of a colon cancer, subtotal colectomy is favored. Evidence supports the efficacy of prophylactic hysterectomy and oophorectomy. CONCLUSIONS: The past 10 years have seen major advances in the understanding of Lynch syndrome. Current recommendations regarding cancer screening and prevention require careful consultation between clinicians, clinical cancer genetic services, and well-informed patients.

Adult↗