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At least 1,225 records · Page 68Linked to original sources
PubMed1997

[Endoscopic results of treating malignant polyps of the large intestine].

We present own material of 291 colonoscopic polypectomies performed between 1991 and 1996. In this group 15 (5.1%) polyps contained malignancy (14 adenocarcinoma, 1 lymphoma). Analysis of this material supported well known fact of higher malignant potential of large polyps and of adenoma villosum. In all but one cases of cancers located in polyps histological examination confirmed free margin of electro-resection. There were no local recurrences during follow-up lasting 2 month to 5.5 years. Patient with lymphoma malignum (large polyp over 4 cm in diameter) underwent typical chemotherapy and is now, one year after polypectomy disease-free. In this group colonoscopy is repeated every 3 months during first two years and every 6 months later. In cases of cancer-free margin of electro-ablation colonoscopic polypectomy seems adequate treatment of malignant large bowel polyps.

Adenocarcinoma↗
PubMed1976

Early detection and prevention of colon cancer. The role of colonscopy.

The incidence of and mortality associated with colon cancer has not decreased during the past 25 years despite several innovations in therapy. Earlier detection and prevention by polypectomy though the sigmoidoscope and colonoscope have been suggested as one alternative offering improvement. The polyp-cancer sequence is controversial, but recent evidence indicates that polyps with a papillary component have a substantial potential for becoming malignant. Forty-four polyps were resected from 26 patients. Nineteen polyps from 14 patients had papillary features of "in-situ" carcinoma. Thus, colonoscopic polypectomy may play an important role not only in early detection but also in the prevention of colon cancer.

Adenoma↗
PubMed1998

[Value of colonoscopy in tumor after-care after colorectal carcinoma].

The significance of colonoscopic follow up is discussed controversially. Colonoscopy after resection of colorectal cancer offers the possibility of direct inspection and to take biopsies for the early detection of local recurrence or additional neoplasms. In a retrospective study we examined the benefit of regular colonoscopies. Between 1/1995 and 4/1996 237 colonoscopies were performed on 164 patients after resection of colorectal cancer. The evaluation was done due to the stage of the primary tumor, the age of the patients, the time after operation and the number of previous colonoscopies. 54 adenomas were found in 35 of 164 patients. 32% of the adenomas were diagnosed in the ascending colon or colon transversum. Additionally three carcinomas were found. There were two local recurrences and one metachronous neoplasm. Two patients were diagnosed without clinical symptoms and were able to undergo potential curative resection again. Because of the number and the localisation of diagnosed neoplasms colonoscopic surveillance should be performed every six months in the first two years after resection of colorectal cancer.

Adenomatous Polyposis Coli↗
PubMed1976

Colonscopic excision of sessile polyps.

Most benign sessile colon polyps can be removed colonoscopically from all reaches of the colon, thus avoiding laparotomy previously required for most of these lesions. Two hundred and fifty colonoscopy procedures were reviewed, revealing 87 sessile colon polyps ranging from 0.5-6.0 cm. in size. Sixty-eight of 87 lesions were excised from 51 patients with just three lesions found to be malignant (invasive adenocarcinoma). Sixteen lesions were felt to be unsuitable for safe colonscopic excision and were, therefore, removed by laparotomy (in 12 patients) and six lesions found to be malignant. Three sessile lesions in this consecutive series were not yet removed at the time of this writing. Thorough bowel preparation and evaluation for other possible lesions are important components of this procedure, which yielded other polyps or cancers in 24 of 66 patients. While most sessile lesions less than 2 cm. in size can be excised endoscopically, certain larger benign sessile lesions can also be removed using piece-meal snare excision technics and radiowave electrocautery (principle of less heat penetration and tissue destruction). Seventy-nine per cent of all sessile colon polyps were excised colonoscopically in this series making abdominal surgery now unnecessary for most colon polyps. Laparotomy is necessary for certain larger benign lesions and all sessile lesions containing invasive cancer.

Colon↗
PubMed1982

A second look at colonoscopy: indications, failures, and costs.

Results of colonoscopy and colonoscopic polypectomy in 599 patients have been reviewed. Added experience has not decreased the number of failures--failure to examine the entire colon, polyps not retrieved for histological examination ("lost polyps"), undetected ("missed") lesions, and false-negative biopsy specimens. The incidence of invasive carcinoma in polyps measuring under 1 cm is less than 1%; polypectomy should be reserved for larger lesions or demonstrated growth of small polyps. Diagnostic colonoscopy in selected patients (those with persistent gross or occult rectal bleeding but normal results from sigmoidoscopic and barium enema studies) demonstrates a causative lesion in greater than 25% and detects a cancer in 5% to 10% of patients.

Biopsy↗
PubMed1985

Colonoscopy in the emergency treatment of colonic volvulus in Nigeria.

The commonest cause of large-bowel obstruction in Nigeria is sigmoid volvulus. Patients usually present late, dehydrated, and in very poor condition. The mortality of emergency colonic surgery is undoubtedly high, more so in developing countries poorly equipped to cope with such a condition. To reduce the mortality rate and improve management of the patients, a four-year prospective study of detorsion followed by elective surgery after adequate resuscitation and bowel preparation was carried out between January 1979 and December 1982. Volvulus is classified into three groups: torsion, obstruction, and strangulation. Criteria for short colonoscopic detorsion of torsion and obstruction types are discussed, and the contraindication in the case of strangulation type mentioned. This article describes the management of 92 cases of sigmoid volvulus between 1979 and 1982.

Adult↗
PubMed1993

Non-radiological technique for three-dimensional imaging of endoscopes.

A novel system is described which images in three dimensions, the total configuration of a colonoscope without the use of conventional radiological techniques. A low intensity magnetic field is used in conjunction with a miniature inductive sensor. The system intrinsically safe and it is potentially inexpensive and capable of being used in a normal hospital environment. Clinical trials are described in which the system is validated in terms of its suitability for the application. Magnetic and conventional X-ray images obtained ex vivo with the endoscope held in various configurations and comparisons in the patients confirm the practical applicability of the new system.

Colonoscopes↗
PubMed2005

Validation of a flexible endoscopy simulator.

BACKGROUND: Virtual reality (VR) simulation is a rapidly proliferating adjunct of surgical training. Numerous devices have evolved as educational tools in a variety of fields. Whether these tools can be used for validation of physicians' skills has yet to be determined. The objective of this study was to determine whether the GI Mentor (Simbionix, Lod, Israel) flexible endoscopy simulator construct could distinguish experienced endoscopists from beginners. METHODS: Seventy-five surgical attendings, fellows, and residents were recruited for participation in the study. Two cohorts were used and these groups were selected from 2 separate scientific sessions. Participants completed a standardized questionnaire documenting their endoscopic training and experience. Physicians subsequently were designated as experienced or beginner after their endoscopic training and experience were evaluated. All participants completed 1 of 2 colonoscopic simulations. The GI Mentor objectively evaluated performance on the basis of programmed data points, including the time to reach the cecum, the percentage of mucosa visualized, the completed polypectomy rate, the percentage of time spent in clear view through the lumen, the percentage of time that the patient was in pain, and overall efficiency. RESULTS: In both simulations, experienced endoscopists were more efficient than beginners (.32%/s vs. .26%/s, P=.02; and .53%/s vs. .37%/s, P=.03) and achieved a greater polypectomy rate (78% vs. 43%, P=.03; and 87% vs. 48%, P=.01). Furthermore, experienced endoscopists visualized more of the colonic surface (86% vs. 82%, P=.02) and spent a greater proportion of the time in clear view of the lumen (55% vs. 47%, P=.05) than beginners completing the first simulation. In the second simulation, experienced participants reached the cecum more rapidly than beginners (175 vs. 262 s, P=.01). CONCLUSIONS: The G1 Mentor VR colonoscopy construct appears valid. Significant performance differences were shown between the experienced and beginner cohorts. The beginner participants in this study were all physicians with some degree of endoscopic experience. Therefore, the G1 Mentor distinguished endoscopists of varying experience and exposure. Further validation studies are needed to evaluate the breadth of programs inherent to this simulator and to determine whether it may be used in the future for qualification and certification purposes.

Clinical Competence↗
PubMed2006

Comparison of Pelican single-use multibite biopsy forceps and traditional double-bite forceps: evaluation in a porcine model.

BACKGROUND: The multibite biopsy forceps is intended for consecutive acquisition of numerous tissue specimens with a single pass. The Pelican multibite forceps is equipped with a sleeve for tissue retention that allows up to 6 specimens to be obtained with each pass of the device through the accessory channel. Reducing the need for device exchange could decrease the total procedure time for colon cancer surveillance in patients with longstanding inflammatory bowel disease (IBD). OBJECTIVE: The aim of this study was to evaluate a new multibite biopsy forceps in comparison with a standard double-bite forceps. DESIGN: Prospective randomized animal model trial. SETTING: Multicenter university and community hospitals. INTERVENTIONS: By using a live porcine model, multiple colonoscopic biopsy specimens were obtained with both the Pelican multibite forceps and the Radial Jaw 3 (RJ3) double-bite forceps to mimic colorectal cancer surveillance in patients with IBD. Six biopsy specimens were obtained with each of 6 passes when using the Pelican forceps, and 2 biopsy specimens were obtained with each of 18 passes when using the RJ3 forceps. MAIN OUTCOME MEASUREMENTS: All trials were timed. Two independent pathologists blinded to the forceps used evaluated the specimens. RESULTS: Tissue acquisition when using the Pelican multibite forceps was significantly faster than with a standard double-bite forceps. The devices compared equivalently for specimen retention and quality. LIMITATIONS: The operator could not be blinded to the devices used. This study uses an animal model to extrapolate how the devices might perform in human use. CONCLUSIONS: These findings support the evaluation of the Pelican forceps for colon cancer surveillance in patients with longstanding IBD.

Animals↗
PubMed2005

Aids to insertion: magnetic imaging, variable stiffness, and overtubes.

Inserting the colonoscope quickly and safely without undue patient discomfort is the primary aim of the colonoscopist. The inherently mobile, flexible and unpredictable nature of the colon means that looping occurs frequently during insertion and the colonoscopist must constantly strive to keep the instrument straight whilst at the same time advancing the tip towards the caecum. Colonoscopists have struggled with insertion for many years but recent developments described in this chapter have the potential to make insertion easier and more predictable.

Catheterization↗
PubMed2004

A novel shape-locking guide for prevention of sigmoid looping during colonoscopy.

BACKGROUND: Looping of the endoscope in the sigmoid colon and other colonic segments often represents a significant challenge to the performance of comfortable, complete, and swift colonoscopy. This report describes the design and operation of a new device that addresses this problem, together with preliminary preclinical experience with this use of this shape-locking guide (SG-1). METHODS: The shape-locking guide is an overtube that can be converted from a flexible to a rigid configuration on demand. When in the rigid configuration, the shape-locking guide is designed to protect the colon wall from lateral forces exerted by the colonoscope. The shape-locking guide was evaluated in vitro by using an artificial colon model to learn how to operate it, and to assess feasibility for prevention of colon looping. In addition, safety was assessed in vivo in a pig model. RESULTS: In vitro, the shape-locking guide prevented colonic looping and, thereby, aided completion of "colonoscopy" in the artificial colon model. Subsequent in vivo studies demonstrated that use of the shape-locking guide is safe and feasible; it performed well with respect to ease of insertion and avoidance of sigmoid looping. There was no evidence of significant injury to the colon or adjacent abdominal viscera. CONCLUSIONS: This preliminary study shows that use of the shape-locking guide is safe and that it has performance characteristics that may assist the performance of colonoscopy. Human trials are being undertaken.

Animals↗
PubMedDate not supplied

Push-enteroscopy for diagnosis of patients with gastrointestinal bleeding of obscure origin.

Push-enteroscopy using a disinfected colonoscope was performed on 39 patients with gastrointestinal bleeding of obscure origin. Our results show that: (1) A high percentage of patients (38%) have pathological lesions responsible for bleeding located in the distal duodenum and proximal jejunum, which are readily detected by push-enteroscopy. (2) Duodeno-jejunal arteriovenous malformations (AVMs) are the most common cause for bleeding, and these lesions can be conveniently cauterized through the endoscope. (3) An efficient sequence of steps for diagnosis of patients with this problem includes push-enteroscopy when the initial EGD and colonoscopy are normal followed by small bowel radiography. Mesenteric angiography and intraoperative enteroscopy can be reserved for patients with severe bleeding when push-enteroscopy and small bowel radiography are negative. We conclude that push-enteroscopy has an important role to play in the early assessment of patients with gastrointestinal bleeding of obscure origin.

Arteriovenous Malformations↗
PubMedDate not supplied

Total colonoscopy: is it always possible?

One-thousand three hundred fifty-one consecutive colonoscopies were performed in an office setting without fluoroscopy. Three different models of colonoscopies were utilized; all were manufactured by the Olympus Corporation of America, and included a videoendoscope, a CF-20L immersible OES-type instrument, and an older fiberoptic colonoscope, CFLB-3W. In all colonoscopies, the cecum was reached in 95.9%, even when an obstructing lesion or stenosis was present. Total intubation was performed in 97% of cases with the videoendoscope, 95.5% with the CF-20L, and 95.7% with the CFLB-3W. In a subgroup of 865 colonoscopies, total colonoscopy was performed in 98% of cases when obstructing lesions (carcinoma or stricture) were excluded from analysis. In this subgroup, total colonoscopy could not be performed in 16 patients because of colonic fixation, tortuosity, or for unknown anatomical reasons. Forty-five percent of this subgroup was female, but of the 16 patients in whom total colonoscopy was not possible, 15 were women, 5 of whom had a previous hysterectomy. We conclude that in the absence of any obstructing lesion, an expert can perform complete colonoscopy in 98% of examinations, and in 95% of all patients presenting for colonoscopy. Total colonoscopy may be more difficult in women than men, but a previous hysterectomy does not seem to adversely affect the ability to perform colonoscopy. The type of instrument used for colonoscopy does not impact on the ability to visualize the entire colon.

Colonoscopes↗
PubMed1995

Endoscopic assessment of invasion of colorectal tumors with a new high-frequency ultrasound probe.

The present study was carried out to clarify the usefulness of and problems associated with a new ultrasound probe in the assessment of invasion of colorectal tumors. Normal colorectal wall of 23 resected specimens from colorectal cancer cases was examined in vitro with the probe. Fifty-one patients with colorectal carcinoma and 16 patients with rectal carcinoid tumor were presurgically examined using the probe via the biopsy channel of a conventional colonoscope. After endoscopic and ultrasonographic examination, 27 patients underwent endoscopic resection and 40 underwent surgical resection. The ultrasonographic findings were compared with histologic findings in all cases. Carcinomas and carcinoid tumors were visualized as an echo-poor region with the probe. The overall accuracy rate for depth of invasion was 76% (39/51) for colorectal cancer. The accuracy rates for tumors limited to the mucosa and tumors invading the submucosa were 83% and 90%, respectively; these rates were higher than those for tumors invading the muscularis propria (50%) and beyond the muscularis propria (73%). In all 16 cases of carcinoid tumor, the depth of invasion was accurately shown to be limited to the submucosa. This probe is useful to assess invasion of colorectal tumors, especially small and flat lesions limited to the mucosa or submucosa.

Adult↗
PubMed1997

Application of magnifying chromoscopy for the assessment of severity in patients with mild to moderate ulcerative colitis.

BACKGROUND: A magnifying colonoscope that enables high-power observation of the colorectal mucosa has been recently developed. The aim of this study was to investigate the value of the magnifying instrument in determining the severity of ulcerative colitis. METHODS: Magnifying colonoscopy was performed in 41 patients with ulcerative colitis, and the findings in the rectum were graded according to network pattern and cryptal openings. These findings were correlated with endoscopic, clinical, and histologic severity of the disease. RESULTS: Magnifying colonoscopy did not detect network pattern in 37% and cryptal opening in 24% of the subjects. The clinical, endoscopic, and histologic grades of activity were not different between groups divided by the presence or absence of each finding. However, when the two features were coupled, patients with visible network pattern and cryptal opening had a lower clinical activity index and lower grade of histologic inflammation than those in whom both findings could not be visualized. CONCLUSIONS: Observation under magnifying colonoscopy can be another clue to determining the severity of disease in patients with ulcerative colitis.

Adolescent↗
PubMed1998

Farewell to bacteremia caused by endoscopic injection--effectiveness of a new injection catheter with a covered tip.

BACKGROUND: Endoscopic injection has recently been reported as effective for several treatments. Because the common channel (suction and biopsy) is usually contaminated with aspirated gastrointestinal juice containing bacteria, often the tip of the injector needle is also. We report a new catheter needle with a covered tip designed to prevent bacteremia from endoscopic injection. METHODS: The new covered needle catheter (Clisco needle) has a 23-gauge retractable needle with a 3 mm extrusion in one lumen. Its distal tip is covered with rubber, blocking infiltration of contaminated gut juice. Ten of these catheters and 10 other disposable needles were inserted through the colonoscope's biopsy channel for 10 patients. Needle tips were cut off after extrusion, and bacteria cultured were counted by standard plate count method. RESULTS: All cultures from ordinary needles grew Escherichia coli, whereas only 3 new needles grew E. coli. Average counts of bacteria cultured from these 3 catheters and 10 disposable needles were 1-250 and 90-6.1 x 10(6), respectively. The difference was highly significant (p < 0.0001). CONCLUSIONS: This new covered needle catheter reduces contaminating bacteria in patients who require endoscopic injection and may prevent bacteremia without antibiotic prophylaxis.

Bacteremia↗
PubMed1999

Micromachines in endoscopy.

Conventional endoscopy has reached a plateau in technical development, necessitating the exploration of bold new ideas in order to make further advances. One such idea is a self-navigating, independent, intelligent colonoscopic micro-robot. The design of a vehicle that can negotiate the difficult and hostile terrain of the colon is a complex task. Options include wheeled or tracked vehicles and pneumatically driven devices. The development of navigation and lesion recognition software to drive such a vehicle is also challenging. The various mathematical concepts involved in the development of such software are explored in this article.

Animals↗
PubMed1999

An initial experience with screening for colon polyps using spiral CT with and without CT colography (virtual colonoscopy)

BACKGROUND: Computed tomographic (CT) colography (virtual colonoscopy) is a new imaging method for detection of colon polyps and cancer. OBJECTIVE: To evaluate the sensitivity of CT colography for polyp detection in a population without symptoms that included persons without colon neoplasia and with radiologists blinded to colonoscopic findings. METHODS: Forty-six persons without symptoms underwent spiral CT followed by same-day colonoscopy with subsequent inspection of two-dimensional axial CT images, interactive multiplanar images, and surfaced and volume-rendered images of the colon (three-dimensional CT colography). RESULTS: Three-dimensional CT colography was superior to two-dimensional axial imaging for detection of colon polyps. Three-dimensional CT colography depicted 1 of 4 (25%) adenomas 2 cm in diameter or larger, 6 of 10 (60%) adenomas 1 to 1.9 cm, 6 of 14 (43%) 6 to 9 mm, and 7 of 65 (11%) 5 mm in diameter or smaller. Three-dimensional CT colography showed a polyp that might have led to colonoscopy in 3 of 4 (75%) patients whose largest adenoma was 2 cm or larger, 5 of 6 (83%) patients with largest adenoma 1 to 1.9 cm, 3 of 7 (43%) patients with largest adenoma 6 to 9 mm, and 4 of 16 patients (25%) with largest adenoma 5 mm or smaller. Large, flat adenomas of the right colon were difficult to identify with three-dimensional CT colography. The specificity of three-dimensional CT colography for patients with adenomas 1 cm in diameter or larger was 89%. Examination of patients with missed adenomas after unblinding indicated that meticulous bowel preparation and adequate distention are critical to accurate interpretation. Perceptual errors were common. CONCLUSIONS: CT colography as performed in this study is not adequate as a colorectal cancer screening test. Several technical factors that appear critical to accurate performance of CT colography are defined.

Adenocarcinoma↗