UNLABELLED: Patients from a hereditary nonpolyposis colorectal cancer (HNPCC) kindred (Lynch Type 1 and Type 2) have an increased risk of developing large-bowel cancer. Tumors occur at a young age and are characteristically right-sided. Colonic mucosal proliferation is known to be increased in several groups of patients at risk of colorectal cancer. PURPOSE: This study was performed to assess the pattern of mucosal proliferation at different sites in the colon of patients at risk of HNPCC and to determine whether this pattern differs from normal patients. METHODS: Mucosal biopsies were obtained at colonoscopy from 21 patients at risk for HNPCC (16 females; mean age, 42 years) and from 7 normal patients (4 females; mean age, 38 years), and mucosal proliferation was quantified using the whole crypt mitotic count (WCMC) technique. RESULTS: In patients from HNPCC families, WCMC and crypt area were significantly greater in the cecum than in the transverse colon and left colon (P < 0.001). Compared with normal patients, WCMC in HNPCC patients was significantly greater in the cecum only (P < 0.05). A significant right-to-left shift was also observed in normal patients, but the percentage increase from right to left was two-fold greater in HNPCC patients. CONCLUSIONS: These results confirm a proximal-to-distal proliferative gradient in the human colon and suggest that this may be exaggerated in HNPCC. This increased proximal proliferative rate may be a factor in the development of right-sided cancer in these patients.

Adult↗

PubMed1997

Immediate recovery of psychomotor function after patient-administered nitrous oxide/oxygen inhalation for colonoscopy.

BACKGROUND AND STUDY AIMS: Previous studies have shown that patients inhaling-self-administered nitrous oxide/oxygen as a sedative/analgesic medication for colonoscopy were ready to leave the endoscopy unit on average sooner than those given conventional intravenous premedication. The aim of this study was to define the time course of recovery after nitrous oxide/oxygen sedation or intravenous opiate/benzodiazepine premedication for colonoscopy. PATIENTS AND METHODS: Consecutive colonoscopy patients were randomized to receive either a 50% nitrous oxide/oxygen mixture (n = 12), or pethidine 25-50 mg and midazolam 2.5 mg (n = 15), or no sedation (n = 10). Psychomotor function was assessed by multiple-choice reaction time, hand-eye co-ordination, and letter deletion tests before and at 15-minute intervals after colonoscopy, with the assessment carried out by an observer blinded to the sedation regime. RESULTS: The mean duration and tolerance of the procedure were similar in the three study groups. Patients receiving nitrous oxide/oxygen mixture were judged (by clinical observation) to recover more quickly than those given conventional sedation (median 8 min, range 3- 25 min, vs. median 16 min, range 3-50 min). Recovery, as judged by a return to baseline in psychomotor function tests, was complete within 30 minutes in all patients receiving the nitrous oxide/oxygen mixture, compared to 50 minutes in those given conventional intravenous sedation. CONCLUSIONS: The rapid recovery observed with nitrous oxide/oxygen sedation for colonoscopy suggests that it is safe for patients to travel unescorted after the procedure. Driving may also be safe soon after nitrous oxide/oxygen sedation, but this requires further clarification.

Analgesia, Patient-Controlled↗

PubMed1997

Real-time magnetic three-dimensional imaging of flexible endoscopy.

Because of the variability of the colonic anatomy from patient to patient, colonoscopy may be technically difficult to perform and teach, and lesions may be localized inaccurately by the endoscopist. Endoscopists understandably have abandoned fluoroscopy as an adjunct because of its expense, complexity, and potential hazard. The authors have developed a novel method of magnetic imaging that gives real-time views in simulated three dimensions of the endoscope configuration and the location of its tip in the abdomen. The system is inherently safe and easy to use, although it currently requires a catheter to be inserted into the instrumentation channel. Preliminary experience suggests that this approach will be a significant help to endoscopists performing colonoscopy, particularly to those who are currently learning or less experienced.

Clinical Competence↗

PubMed1996

Why is colonoscopy more difficult in women?

BACKGROUND: In our experience colonoscopy in women is more difficult than in men. A retrospective review of 2194 colonoscopies performed by a single experienced endoscopist (CBW) showed that 31% of examinations in women were considered technically difficult compared with 16% in men. METHODS: To investigate a possible anatomic basis for this finding, normal barium enema series from 183 female and 162 male patients were identified. From these barium enemas, measurements of colonic length and mobility were independently taken by two physicians who were unaware of each patient's gender. RESULTS: Total colonic length was greater in women (median, 155 cm) compared to men (median, 145 cm), p = 0.005, despite women's smaller stature (p < 0.0001). Although there were no significant differences in rectum plus sigmoid, descending, or ascending plus cecum segmental lengths, women had longer transverse colons (female median length, 48 cm; male median length, 40 cm), p < 0.0001. There were no differences in mobility of the descending colon and transverse colon between the sexes, but the transverse colon reached the true pelvis more often in women (62%) than in men (26%), p < 0.001. CONCLUSIONS: Colonoscopy appears to be a technically more difficult procedure in women. The reason for this may be due in part to an inherently longer colon.

Adolescent↗

PubMed1996

Premedication with intravenous antispasmodic speeds colonoscope insertion.

BACKGROUND: Use of antispasmodic medication prior to colonoscopy is controversial but may improve visualization of colonic mucosa and ease colonoscope insertion. METHOD: The effects on the performance of colonoscopy by premedication with the antispasmodic hyoscine n-butyl bromide were studied in a prospective, double-blind, placebo-controlled trial. Fifty-six consecutive patients were randomly assigned to receive intravenous hyoscine 20 mg (n = 29) or placebo (n = 27) in conjunction with our standard initial medications (meperidine 0.7 mg/kg and midazolam 0.03 mg/kg). Insertion and withdrawal of the colonoscope were timed, and 100 mm visual analogue scales were used to assess procedure difficulty, colonic motility, and the degree of discomfort experienced by the patients. RESULTS: In those patients receiving hyoscine, intubation time was quicker (median hyoscine, 13 minutes; median placebo, 17.5 minutes, p = 0.045) and colonic spasm less (median hyoscine, 19 mm; median placebo, 53.5 mm, p = 0.01). The procedure was considered significantly less difficult in the hyoscine group (median, 23.5 mm) compared to the placebo group (median, 50), p <0.05. No significant differences in withdrawal time or patient pain scores were found. CONCLUSIONS: Premedication with intravenous hyoscine n-butyl bromide reduces colonic spasm and in this study made colonoscope insertion significantly quicker and easier.

Adult↗

PubMed1996

Laboratory acquired verotoxin producing Escherichia coli (VTEC) infection.

Explore the source record for details and available documents.

Adult↗

PubMed1996

Psychological aspects of gastrointestinal endoscopy: a review.

Explore the source record for details and available documents.

Adaptation, Psychological↗

PubMed1995

Intraoperative measurement of colonic anatomy and attachments with relevance to colonoscopy.

This study examined the variations in colonic length and mesenteric attachments in 118 patients undergoing laparotomy. Measurements were taken according to a set protocol with the bowel pulled medially, or towards the pubic symphysis or the xiphisternum, mimicking the possible displacements that may occur during colonoscopy. A free sigmoid loop was not present in 20 patients (17 percent) because of adhesions. A descending mesocolon of 10 cm or more in length was recorded in ten patients (8 percent) and an ascending mesocolon 10 cm or greater in 11 (9 percent). Some 24 patients (20 percent) had mobile splenic flexures and in 34 (29 percent) the mid-transverse colon reached the symphysis pubis or lower when pulled downwards. Mean (range) total colonic length was 114.1 (68-159) cm. This study helps define anatomical variations that may affect the facility, or otherwise, of colonoscopy.

Adult↗

PubMed1995

A peroperative comparison of Western and Oriental colonic anatomy and mesenteric attachments.

It has been suggested that the Oriental colon is easier to colonoscope than its Western counterpart. The aim of this study was to investigate possible differences in colonic anatomy between Western and Oriental patients that might explain this observation. Measurements of colonic length and mesenteric attachments were taken according to a set protocol from 115 Western (Caucasian) and 114 Oriental patients at laparotomy. Sigmoid adhesions were found more frequently in Western (17%) compared to Oriental (8%) patients, P = 0.047. A descending mesocolon of > or = 10 cm occurred in 10 (8%) Western patients but only 1 (0.9%) Oriental patient, P = 0.01. The splenic flexure was more frequently mobile in Western patients (20%) compared to Oriental (9%) patients, P = 0.016. In 29% - of Western patients the mid-transverse colon reached the symphysis pubis, or lower when pulled downwards in contrast to 10% of Oriental patients, P < 0.001. There was no significant difference in total colonic length comparing Western (median = 114 cm, range 68-159 cm) to Oriental (median = 111 cm, range 78-161 cm) patients. Western patients have a higher incidence of sigmoid colon adhesions and increased colonic mobility when compared to Orientals. These findings support the observation that colonoscopy is a more difficult procedure in Western patients.

Adult↗

PubMed1995

Can barium enema indicate when colonoscopy will be difficult?

The barium enemas of 48 consecutive patients, who were technically difficult to intubate at colonoscopy, were compared to those of 46 patients who were not. Measurements were taken of colonic length and mobility, and an assessment made of diverticular disease. Rectosigmoid length (mean difficult group = 61 cm, mean control = 54 cm, P = 0.01) and total colonic length (mean difficult group = 157 cm, mean control = 140 cm, P < 0.0001) were greater in the difficult colonoscopy group as were transverse colon mobility (mean difficult group = 10 cm, mean control = 7 cm, P = 0.003) or redundancy (transverse colon reaching the true pelvis on the erect film); 65% difficult group vs 17% control group, P < 0.0001. The presence of moderate or severe diverticular disease was also greater in the difficult (23%) compared to the control (4%) group, P = 0.02. When available, assessment of a previous barium enema is a useful guide to probable technical difficulty of colonscopy. It may allow appropriate allocation of potentially difficult cases to specialist endoscopy lists.

Adolescent↗

PubMed1995

Intravenous antispasmodic and patient-controlled analgesia are of benefit for screening flexible sigmoidoscopy.

The possible benefits of premedication with the antispasmodic hyoscine n-butyl bromide (hyoscine) and analgesia with inhaled nitrous oxide/oxygen mixture (nitrous oxide) were assessed in a double-blinded, placebo-controlled trial. Consecutive patients at normal risk for cancer undergoing screening flexible sigmoidoscopy were randomly allocated to receive either (1) intravenous hyoscine 20 mg plus inhaled oxygen on demand (n = 40), (2) sterile water injection plus inhaled nitrous oxide on demand (n = 48), or (3) sterile water injection plus inhaled oxygen on demand (n = 43). One recently trained primary care physician performed all procedures. Duration of the procedure, endoscopic findings, and depth of insertion were recorded. After the examination, screenees rated their degree of pain during the procedure using a visual analogue scale. Depth of insertion did not differ between the three study groups, but the duration of the procedure was significantly less in the hyoscine group (median, 12.5 minutes) as compared with placebo (median, 18 minutes; p = .0008). Fifty-four percent of screenees chose to use the on-demand gas. Pain scores were significantly lower in those individuals who inhaled nitrous oxide as compared with placebo (p = .045). Premedication with antispasmodic shortens total procedure time for flexible sigmoidoscopy by a moderately experienced endoscopist as compared with placebo. In this study, a significant number of screenees experienced discomfort during flexible sigmoidoscopy, which appeared to be reduced by offering nitrous oxide inhalation.

Administration, Inhalation↗

PubMed1995

The role of small bowel radiology in the diagnosis and management of Crohn's disease.

A total of 50 children with Crohn's disease were examined by barium follow-through and colonoscopy with ileoscopy, to determine the value of small bowel radiology. Of these children, 40 (80%) had evidence of small bowel Crohn's disease on ileoscopy and/or barium follow-through. Twenty-two (44%) had disease confined to the terminal ileum. Radiology diagnosed disease proximal to the terminal ileum in 18 cases (36%), including 5 children in whom the terminal ileum was normal. Ileoscopy was not possible in nine patients (18%), six of whom had small bowel disease on barium follow-through. Colonic involvement, demonstrated in 34 (68%), was the sole site of disease in 6 (12%). Fifteen (30%) children had surgery, which in six (12%) was determined by the radiological findings of complicated small bowel disease. As the terminal ileum may be uninvolved in the presence of proximal ileal disease, normal ileoscopy does not exclude small bowel Crohn's disease. Small bowel radiology remains necessary to assess the full extent of Crohn's disease in children.

Adolescent↗

PubMed1995

First clinical results with a real time, electronic imager as an aid to colonoscopy.

The early clinical results are described of a real time, electromagnetic imaging system as an aid to colonoscopy. After gaining experience with the use of the system, one experienced endoscopist was randomised to perform consecutive colonoscopies either with (n = 29) or without (n = 26) the imager view. All procedures were recorded on computer disk and replayed for retrospective analysis. Total colonoscopy was achieved in all patients except one (imager view not available). Comparing intubation time and duration of loop formation per patient, there was no significant difference between the two study groups. The number of attempts taken to straighten the colonoscope pre patient, however, was less when the endoscopist was able to see the imager view, p = 0.03. Hand pressure was also more effective when the endoscopist and endoscopy assistant could see the imager display, p = 0.02. Preliminary experience suggests that real time, electronic imaging of colonoscopy is safe, effective, and will improve the accuracy of the procedure.

Abdomen↗

PubMed1995

The quest for a more acceptable bowel preparation: comparison of a polyethylene glycol/electrolyte solution and a mannitol/Picolax mixture for colonoscopy.

Eighty-nine consecutive patients attending for day-case colonoscopy were randomly allocated either polyethylene glycol/balanced electrolyte (PEG) mixture (n = 45) or a mannitol/Picolax mixture (n = 44). Both preparations were administered in two fractions. Patients recorded their experience of the preparation on a questionnaire and one of two experienced endoscopists (unaware of the type of preparation given) assessed the result of bowel cleansing. Carbon dioxide insufflation was used for all examinations. Good/excellent bowel cleansing occurred in significantly more patients given PEG, 43 (96%), than those allocated mannitol/Picolax, 34 (77%), p = 0.01. More patients receiving mannitol/Picolax were able to complete the preparation in full than patients receiving PEG (38 vs 27, p = 0.01). More patients found the taste of mannitol/Picolax pleasant compared to PEG (46% vs 20%). Both preparations had a similar side-effect profile. Of those patients tested, 13% receiving mannitol/Picolax had a postural drop in blood pressure and blood parameters suggestive of mild dehydration. A fractionated administration of PEG as a bowel preparation for day-case colonoscopy is well tolerated and superior as a cleansing agent to a mannitol/Picolax combination. Provided carbon dioxide is used as the insufflating agent, mannitol/Picolax is an acceptable alternative in fit, young patients intolerant of PEG.

Administration, Oral↗