Effect of magnetic endoscope imaging on patient tolerance and sedation requirements during colonoscopy: a randomized controlled trial

BACKGROUND: Pain during colonoscopy is primarily related to mesenteric stretching from looping of the colonoscope insertion tube. Prompt recognition and removal of loops reduces patient discomfort and may lessen sedation requirements. Magnetic endoscope imaging allows real-time visualization of the colonoscope during insertion. The effect of magnetic endoscope imaging on patient pain and sedation requirements was assessed in a prospective randomized controlled trial. METHODS: A total of 122 consecutive patients undergoing routine colonoscopy by a single experienced endoscopist were randomized to have the procedure performed either with the endoscopist viewing the imager display (n = 62), or without the imager view (n = 60). Procedures began with administration of hyoscine-N-butylbromide alone, and sedative medications (midazolam and meperidine) were self-administered by the patient with a patient-controlled analgesia pump. Cardiorespiratory parameters were recorded and patient pain was assessed with a 100-mm visual analogue scale. RESULTS: The number of attempts at straightening the colonoscope was fewer (median 8 [0-66] vs. 15 [0-87], p = 0.0076) and the duration of looping less (median 4.5 min [0-27.3 min] vs. 6.4 min [0-29.4 min]), when the endoscopist was able to see the imager view. The total number of patient demands (by patient-controlled analgesia) for medication (median 1 vs. 2.5) and total doses of midazolam (median 0.44 mg vs. 0.88 mg) and meperidine (median 16.75 mg vs. 32.5 mg) administered did not significantly differ between patients examined with or without the imager. Patient pain scores were also similar. CONCLUSIONS: Magnetic endoscope imaging allows accurate assessment and straightening of loops during colonoscopy, but without a significant reduction in patient requirements for sedative medication or improvement in patient tolerance. However, the dosages of sedation drugs used were small.     

The variable stiffness colonoscope: assessment of efficacy by magnetic endoscope imaging

BACKGROUND: Variable-stiffness colonoscopes combine the flexibility of pediatric instruments for negotiation of the sigmoid colon with the ability to stiffen the insertion tube to prevent or control looping after straightening. Previous studies have found wide variation in the efficacy of the stiffening mechanism. Thus, two studies were conducted to assess the potential benefit of the stiffening device and its optimal use. METHODS: In study 1, the effect of routinely stiffening the straightened variable-stiffness colonoscopes in the mid-descending colon was determined in 82 patients. Two insertions were performed (mid-descending colon to cecum) in each patient with and without application of the stiffening device (randomized). The time to negotiate the proximal colon (mid-descending to cecum), time to pass the variable-stiffness colonoscopes across the splenic flexure into the transverse colon, time to pass the right colon, and ancillary maneuvers used were recorded for each insertion. In study 2, consecutive patients, excluding any with previous colonic resection, were examined by using standard adult variable-stiffness colonoscopes. Real-time views of the procedure with magnetic endoscope imaging were recorded for all examinations, but procedures were randomized to be done either with (n = 88), or without (n = 87) the endoscopist viewing the magnetic endoscope imaging display. Whenever stiffening was applied, the anatomic location of the colonoscope tip and stiffness efficacy were recorded. RESULTS: In study 1, time taken to negotiate the proximal colon (p = 0.0041) and time to negotiate the splenic flexure (p = 0.006) were significantly shorter and ancillary maneuvers performed were fewer (p = 0.0014) with the stiffening device activated. In study 2, stiffening was used with similar frequency in patients examined with and without the magnetic endoscope imaging view, most commonly for passing the splenic flexure (71%), but also in the transverse colon (12%), right colon (9%), and sigmoid/descending colon (8%). Stiffening was significantly more effective when used in combination with magnetic endoscope imaging (69% with imager vs. 45% without imager; p = 0.0102). CONCLUSIONS: Overall, the variable-stiffness device used was effective in controlling looping 57% of the time. Activating maximum stiffness appears to be effective once the sigmoid colon has been negotiated and the colonoscope straightened with the tip in the proximal colon, reducing the number of ancillary maneuvers and shortening the insertion time through the proximal colon. Routine magnetic endoscope imaging further enhances the efficacy of the variable-stiffness colonoscopes by helping to identify the optimal time for stiffening.     

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.     

The technique of abdominal pressure in total colonoscopy

Total colonoscopy can be difficult. It is recognized that abdominal pressure can be helpful in the performance of colonoscopy by externally splinting the endoscope to prevent loop formation. Properly applied abdominal pressure can limit patient discomfort and shorten examination time. Various techniques for abdominal pressure were studied in 201 consecutive patients who had total colonoscopy to the cecum. Abdominal pressure or change of body position was used 619 times in 165 patients (82%), with an average of 3.75 pressure applications per colonoscopy, most lasting less than 30 sec. Pressure was most commonly used when the endoscope tip was at the splenic flexure. Non-specific pressure to a region of the abdomen where looping developed, endoscopically observed specific pressure near the tip, and position change were used in a stepwise manner. Non-specific pressure was more successful in the left (78%) than in the right (47%) colon (p less than 0.0005). As intubation progressed left to right, specific pressure became more useful. When abdominal pressure was not useful, a change in patient position from left lateral to supine was successful in advancing the endoscope tip in 68% of patients.     

Magnetic imaging-assisted colonoscopy vs conventional colonoscopy: A randomized controlled trial

AIM: To compare magnetic imaging-assisted colonoscopy (MIC) with conventional colonoscopy (CC).METHODS: Magnetic imaging technology provides a computer-generated image of the shape and position of the colonoscope onto a monitor to give visual guidance to the endoscopist. It is designed to improve colonoscopy performance and tolerability for patients by enabling visualization of loop formation and endoscope position. Recently, a new version of MIC technology was developed for which there are limited data.To evaluate this latest generation of MIC among experienced rather than inexperienced or trainee endoscopists, a prospective randomized trial was performed using only gastroenterologists with therapeutic endoscopy training. Consecutive patients undergoing elective outpatient colonoscopy were randomized to MIC or CC, with patients blinded to their group assignment. Endoscopic procedural metrics and quantities of conscious sedation medications were recorded during the procedures. The procedure was classified as “usual” or “difficult” by the endoscopist at the conclusion of each case based on the need for adjunctive maneuvers to facilitate endoscope advancement. After more than one hour post-procedure, patients completed a 10 cm visual analogue pain scale to reflect the degree of discomfort experienced during their colonoscopy. The primary outcome was patient comfort expressed by the visual analogue pain score. Secondary outcomes consisted of endoscopic procedural metrics as well as a sedation score derived from standardized dose increments of the conscious sedation medications.RESULTS: Two hundred fifty-three patients were randomized and underwent MIC or CC between September 2011 and October 2012. The groups were similar in terms of the indications for colonoscopy and patient characteristics. There were no differences in cecal intubation rates (100% vs 99%), insertion distance-to-cecum (82 cm vs 83 cm), time-to-cecum (6.5 min vs 7.2 min), or polyp detection rate (47% vs 52%) between the MIC and CC groups. The primary outcome of mean pain score (1.0 vs 0.9 out of 10, P = 0.41) did not differ between MIC and CC groups, nor did the mean sedation score (8.2 vs 8.5, P = 0.34). Within the subgroup of cases considered more challenging or difficult, time-to-cecum was significantly faster with MIC compared to CC, 10.1 min vs 13.4 min respectively (P = 0.01). Sensitivity analyses confirmed a similar pattern of overall findings when each endoscopist was considered separately, demonstrating that the mean results for the entire group were not unduly influenced by outlier results from any one endoscopist.CONCLUSION: Although the latest version of MIC resulted in faster times-to-cecum within a subgroup of more challenging cases, overall it was no better than CC in terms of patient comfort, sedation requirements and endoscopic procedural metrics, when performed in experienced hands.     

The Cath-Cam: a new concept in colonoscopy

BACKGROUND: Guidewires and catheters exert less force on the gut wall than an endoscope. OBJECTIVE: To develop a guidewire-assisted device for colonoscopy. METHODS: A light-weight flexible catheter illuminated with light-emitting diodes was designed to carry an ultraslim high-resolution videoendoscope of 3 mm. Tip bend stiffness was 5 times less than a colonoscope. Hinged guidewires were passed, folded, through the accessory channel. A loop could be rapidly formed to explore the lumen. RESULTS: The catheter followed curves of excised pig colon and exerted significantly less force on the colon wall than a colonoscope (mean 1.6 +/- 0.23 N vs 3.0 +/- 0.37 N, P < .05; bend-radius, 80 mm). Survival studies in pigs showed that the guidewire loop could be advanced under visual control and the Cath-Cam could be advanced by using much less force than the colonoscope. CONCLUSIONS: A catheter-based colonoscope with a miniature video imager reduced the force required for successful colonoscopy in pigs.     

Magnetic endoscopic imaging saves abdominal compression and patient pain in routine colonoscopies

OBJECTIVE: Magnetic endoscope imaging (MEI) is a technique for the direct visualisation of endoscope configuration within the colon. This method may prevent loop formation by giving visual feedback of endoscope movement. This study aimed to evaluate the efficacy of MEI in improving colonoscopy performance. METHODS: Overall 1000 consecutive patients who underwent a complete routine colonoscopy were randomized into two groups: in group A with MEI, while in group B without MEI. Sedation was performed according to local standards. In both groups time to reach the cecum, the number of positioning maneuvers and involvement of a second assistant nurse were recorded. Abdominal compression was graded from 1 to 4 according to the duration and intensity of compression was quantified using a scale from 1–3 according to compression form and patient reaction. RESULTS: Patients were randomized (group A with MEI, n = 490; group B without MEI, n = 510) and a total colonoscopy was performed. Time to cecal intubation did not differ between the groups (507 s vs 538 s; NS). The duration of abdominal compression was significantly shorter in MEI guided colonoscopy. The intensity of abdominal compression was lower in group A and fewer turn maneuvers needed per patient. A trend towards a reduced need for assistance in MEI group was seen. CONCLUSION: Although MEI does not generally accelerate colonoscope advancement, it significantly reduces the force and the duration of abdominal compression by assistant personnel, thus minimizing patient discomfort and decreasing the need for additional staff.     

Usefulness of a small-caliber, variable-stiffness colonoscope as a backup in patients with difficult or incomplete colonoscopy

OBJECTIVES: Although variable-stiffness colonoscopes have been developed, difficult or incomplete colonoscopies occasionally occur. The aim of this study was to evaluate the usefulness of a small-caliber, variable-stiffness colonoscope (scVSC) as a backup in patients with difficult or incomplete colonoscopies. METHODS: First, we retrospectively reviewed the cecal intubation rate of colonoscopies in which an adult standard colonoscope (AC) was immediately switched to an scVSC in all patients in whom a colonoscopy with an AC was incomplete. Second, 374 consecutive patients were randomized to undergo colonoscopy with a pediatric variable-stiffness colonoscope (PVSC, n = 123), AC (n = 125), or scVSC (n = 126). The scVSC was used by the same endoscopist to reattempt colonoscopy immediately after colonoscopy with a PVSC or an AC had been assessed as difficult or incomplete. The cecal intubation rate and time and the ancillary maneuvers used were evaluated. RESULTS: Fifty-two (2.5%) of the 2,056 attempted colonoscopies with an AC did not reach the cecum. Fifty-one of the 52 patients (98.1%) had complete colonoscopies after the switch from the AC to the scVSC. The initial intubation rate and time were not statistically different among the groups: PVSC, 95% and 6.8 min; AC, 91% and 7.5 min; and scVSC, 98% and 8.2 min. Cecal intubation was achieved in all five patients (100%) and in 10 out of 11 (91%) patients, respectively, after the PVSC or AC was switched to the scVSC. CONCLUSIONS: The completion rate markedly improved after switching from an AC or PVSC to an scVSC in difficult or incomplete colonoscopies, although the scVSC does not appear to offer any distinct advantage over the AC or PVSC for routine colonoscopies.     

Computer-assisted colonoscopy (the NeoGuide Endoscopy System): results of the first human clinical trial ("PACE study")

OBJECTIVES: Unsedated colonoscopy is an uncomfortable procedure for most patients. Discomfort during colonoscopy is largely related to looping of the colonoscope, which displaces the colon from its native configuration and stretches attachments to the mesentery. A novel computer-assisted colonoscope utilizes a fully articulated, computer-controlled insertion tube. On manual insertion of the colonoscope, the position and angle of the scope's tip are encoded into a computer algorithm. As the colonoscope is advanced, the computer directs each successive segment to take the same shape that the tip had at a given insertion depth. The insertion tube thus changes its shape at different insertion depths in a "follow-the-leader" manner. METHODS: This initial clinical trial with this novel colonoscopy system was designed as a prospective, nonrandomized, unblinded, feasibility study. Three physicians of varying levels of experience participated in the study. RESULTS: Eleven consecutive patients (seven men, four women, age range 19-80) meeting inclusion criteria for screening or diagnostic colonoscopy were enrolled in the study. The cecum was reached in 10 consecutive patients (100%). Findings included diverticular disease in two cases and multiple colonic polyps in two cases. Postprocedure assessment at discharge, 48 h, and 30 days revealed no complications or adverse effects. Physician satisfaction and patient acceptance of this new technique were high. CONCLUSIONS: In this limited, first of its kind feasibility study, the computer-assisted colonoscope was shown to perform colonoscopy safely and effectively. The colonoscope's unique design limited loop formation during colonoscopy. Large-scale clinical trials are indicated.     

Sedation-free colonoscopy using an upper endoscope is tolerable and effective in patients with low body mass index: a prospective randomized study

OBJECTIVE: Small-caliber upper endoscopes can be used safely and effectively for sedation-free colonoscopy. The objective of the study is to assess the efficacy of a small-caliber upper endoscope (9.2 mm) comparing with a standard colonoscope (12.2 mm). METHODS: In a prospective trial, patients undergoing sedation-free colonoscopy were randomly assigned to the upper endoscope (E) or the standard colonoscope (C). Outcome measures included patient self-assessed pain score (4-point scale), endoscopist-assessed pain score (4-point scale), cecal intubation rate, difficult cecal intubation rate (>900 s), number of polyps detected, and complication rates. RESULTS: A total of 244 patients were entered. Clinical characteristics were not different between the two groups. Cecal intubation was achieved in 91.0% of the patients in each group. The mean patient self-assessed pain score (SD) was significantly lower in the E group compared with the C group: 1.44 (0.81) versus 2.08 (1.10), p < 0.001. The mean endoscopist assessment of patient pain score (SD) was significantly lower in the E group compared with the C group as well: 1.27 (0.67) versus 1.58 (0.90), p= 0.003. In patients with low body mass index (BMI < 22 kg/m(2)), the cecal intubation rate was significantly higher in the E group (97.7%vs 79.4%, p= 0.026) and the difficult cecal intubation rate was significantly lower in the E group (9.3%vs 32.4%, p= 0.011). There were no significant differences in the number of polyps detected and complication rates between the two groups. CONCLUSION: A small-caliber upper endoscope is tolerable and effective for sedation-free colonoscopy, especially in patients with low BMI.     

Usefulness of a pediatric colonoscope for colonoscopy in adults

BACKGROUND: There are few published data on how different types of colonoscopes affect success in reaching the cecum and patient comfort. We examined the feasibility of using a pediatric colonoscope for routine colonoscopy in adults and investigated whether there were subgroups of patients in whom use of this instrument was preferable. METHODS: One-hundred fifty adults undergoing outpatient colonoscopy were randomized to colonoscopy with a standard colonoscope (Olympus CF-100L) or with a pediatric colonoscope (Olympus PCF-100). All procedures were performed by a faculty endoscopist and timed by an independent observer. After examinations, the endoscopist graded procedure difficulty and patients were given a questionnaire that assessed their experience. RESULTS: The adult (n = 77) and pediatric (n = 73) colonoscope groups were comparable in all outcomes measured, including success in reaching the cecum (91% vs. 93%, p = 0.61), mean time to reach the cecum (11.4 vs. 9.7 min, p = 0.07), mean total procedure time (21.8 vs. 21.9 min, p = 0.95), mean meperidine dose (55 vs. 52 mg, p = 0.17); median midazolam dose (2.0 mg in both groups, p = 0.10), the endoscopists' perception of procedure difficulty, and patient comfort scales. Of the 7 patients in whom colonoscopy with the adult colonoscope was unsuccessful, the cecum was reached in 4 by switching to a pediatric colonoscope (all women, 3 of whom had prior hysterectomy). In the 5 patients in whom colonoscopy with the pediatric colonoscope was unsuccessful, the cecum was reached in 1 by switching to an adult colonoscope. Including the cases in which the cecum was reached by switching to the alternative colonoscope, the overall frequency of cecal intubation was 143 of 150 (95%). Subgroup analysis disclosed no difference between the 2 groups in outcomes when gender, presence of diverticulosis, and patient size were considered. Colonoscopy with the pediatric colonoscope was more successful than with the adult instrument in reaching the cecum in women with prior hysterectomy (11 of 12 [92%] vs. 15 of 21 [71%]); however, the numbers in each group were relatively small and the difference was not significant (p = 0.22). CONCLUSIONS: The pediatric colonoscope is suitable for routine colonoscopy in adults. It is also useful in patients in whom colonoscopy with the adult colonoscope is unsuccessful in reaching the cecum (particularly in women). Additional study is needed to see if the pediatric colonoscope is actually superior to the adult colonoscopy for routine colonoscopy in women with prior hysterectomy.     

Upper gastrointestinal endoscopy—How far does the endoscope go?

Two adult-size endoscopes (Olympus GIF-K2 and ACMI TX-8) were compared for extent of duodenal intubation by the endoscopist's estimate of location and x-ray position in 55 patients. The endoscopes were not different in duodenal position when separately analyzed for the endoscopist's estimate or x-ray location. Combining the results for both endoscopes showed the endoscopist's estimate to differ significantly from x-ray location in 47% of patients (p = 0.02). When incorrect, the endoscopist overestimated 62% of the time and underestimated 38% of the time. X-ray evaluation of insertion depth confirmed that the second portion of the duodenum was reached in 96%, third portion in 51%, and fourth portion or beyond in 38% of patients. We conclude that fluoroscopic confirmation may be necessary when endoscopically assessing distal duodenal segments for pathology.     

Cecal intubation rate with the double-balloon endoscope after incomplete conventional colonoscopy: A study in 45 patients

Background and Aim:  Conventional colonoscopy is the gold standard for colorectal cancer screening. However, a failure rate to complete conventional colonoscopy of more than 10% is reported in the literature. We evaluated whether the therapeutic Fujinon double-balloon endoscope EN-450T5/20 is a valuable tool to intubate the cecum and to carry out all conventional endoscopic procedures after incomplete conventional colonoscopy.
Methods:  Forty-five consecutive patients with prior incomplete conventional colonoscopy were prospectively enrolled. All but three procedures were carried out under conscious sedation with the patient in the left lateral decubitus position without fluoroscopic guidance.
Results:  The cecum was reached in 42 of 45 patients (93%) and in 62% additional therapeutic interventions were carried out. Double-balloon colonoscopy required less conscious sedation compared to conventional colonoscopy. No external abdominal compression nor fluoroscopic control was used. The insertion depth of the double-balloon endoscope did not exceed the working length of a conventional colonoscope.
Conclusions:  The present study illustrates that the concept of double-balloon endoscopy is a valuable alternative to reach the cecum after prior incomplete conventional colonoscopy, especially due to redundant colon and colonic loop formation. The procedure requires less conscious sedation and no fluoroscopic control, but allows all conventional endoscopic interventions.     

Is the variable-stiffness paediatric colonoscope more effective than a standard adult colonoscope for outpatient adult colonoscopy?: A randomised controlled trial

BACKGROUND: Trials with variable-stiffness colonoscopes have yielded conflicting results regarding efficacy and patient tolerance. AIM: We compared a variable-stiffness paediatric colonoscope with a standard adult colonoscope. METHODS: Two hundred and forty consecutive adult outpatients presenting for colonoscopy were randomised to either a variable-stiffness paediatric colonoscope or an adult colonoscope. If there was difficulty in performing colonoscopy with the assigned scope, the endoscopist was given the option of switching to the alternative instrument. In the condition of a severely fixed, angulated sigmoid colon, a final 'salvage' (backup) option was that of switching to an even thinner diameter paediatric colonoscope. RESULTS: The initial frequency of total colonoscopy was similar with the variable-stiffness paediatric colonoscope and adult colonoscope (95.8% versus 96.6%, p=1.0). Factoring in scope changes, the final frequency was 98.3% versus 99.2% (p=1.0). There was no statistical difference between the two groups in terms of insertion time, doses of sedative medications, scales of procedure difficulty, or patient satisfaction. CONCLUSIONS: Adult colonoscope and variable-stiffness paediatric colonoscope are both effective instruments for routine colonoscopy. In cases when the use of the initial scope is unsuccessful, switching to the alternative scope may permit passage to the caecum. There are occasional patients with fixed, angulated sigmoid colons in whom use of an even thinner diameter paediatric colonoscope can be helpful.     

Early use of magnetic endoscopic imaging by novice colonoscopists: improved performance without increase in workload

BACKGROUND

Magnetic endoscopic imaging represents a recent advance in colonoscopy training. This technique provides adjunct information to the endoscopist, specifically with regard to colonoscope loop formation.

OBJECTIVE

To examine the effect of a magnetic endoscopic imager on novice performance and workload in colonoscopy.

METHODS

Twenty complete novices received an introductory teaching session followed by the completion of two procedures on a colonoscopy model. One-half of the participants performed their first procedure with the imager, and the second procedure without, while the other one-half were trained with the inverse sequence. Two main outcome measures were recorded: distance achieved and total workload as measured by the National Aeronautics and Space Administration task load index tool.

RESULTS

A significant improvement was noted between the first and second colonoscopies, with the best performance recorded for participants who performed their first procedure with the imager, and their second without. The imager did not significantly change the total workload.

DISCUSSION

The study participants paid attention to the magnetic endoscopic imager; however, this did not translate into a measurable increase in novice workload. A delayed learning benefit was conferred to the group exposed to the imager on their first colonoscopy, suggesting that, even at an early training stage, the additional imager information entered working memory and was processed in a useful fashion. The introductory teaching strategy used in the present study was successful as judged by the overall distance achieved and performance improvement seen in all study participants.     

Inadequacy of colonoscopy revealed by three-dimensional electromagnetic imaging

INTRODUCTION: It is generally accepted that clinicians performing colonoscopy should reach the cecum in at least 90 percent of examinations. However, little attention has been paid to whether the endoscopist correctly estimates the amount of colon actually seen. METHODS: During colonoscopy, endoscopists were asked to state how far they had reached. This was compared with the amount of colon actually seen, as assessed by a novel electromagnetic imaging device that recorded a three-dimensional position of the scope within a magnetic field pervading the patient's abdomen. If electromagnetic imaging showed that the cecum had not been reached, the endoscopist was asked to use the electromagnetic imaging system to determine whether it helped advance the colonoscope further. RESULTS: In 119 patients undergoing colonoscopy, clinical assessment of position reached was correct in only 92 (77.3 percent). When the endoscopists stated that cecal landmarks had been seen (n=85), the scope was distal to the cecum in seven cases (8.2 percent). When cecal landmarks had not been seen (n=34), the endoscopist's assessment of the position of the scope was accurate in only 14 (41.2 percent). The use of electromagnetic imaging in this latter group assisted passage to the cecum in 26 cases (76.5 percent). CONCLUSION: Despite assumed visualization of the cecum, inadequate colonoscopy highlights the potential for missing significant pathology in the right colon.The electromagnetic imaging system used in this study was donated by the University Department of Electronics, University of Sheffield, United Kingdom.Presented in part or in full at the British Society of Gastroenterology Meeting, Harrogate, United Kingdom, March 10, 1998; the Royal Society of Medicine Section of Coloproctology Meeting, Grenoble, France, April 15, 1998; and the Tripartite Meeting, Washington, DC, May 4, 1999.     

Variable stiffness colonoscopes are associated with less pain during colonoscopy in unsedated patients

OBJECTIVES: Application of a new variable stiffness colonoscope (VSC) is expected to control loop formation and to lessen patient discomfort. The aim of this prospective study was to compare the efficacy of VSC with a conventional colonoscope (CC) in unsedated colonoscopy, based on the experience of examiners. METHODS: Four-hundred sixty-seven patients were randomly assigned to undergo colonoscopy with either VSC or CC by an endoscopist, including experienced and less-experienced examiners. The percentages of completed procedure and time to cecal intubation were recorded. Patients were asked to rate pain on a 5-point pain score. RESULTS: The percentages of completed procedure with VSC and CC were 98% and 95%, respectively, by less-experienced hands, and 99% and 98%, respectively, by experienced hands. Time for cecal intubation with VSC and CC was 15.7 and 18.5 min, respectively, by less-experienced hands, and 9.8 and 10.6 min, respectively, by experienced hands. A significantly lower mean pain score was noted in VSC patients compared with CC patients, irrespective of experience of the examiner. The percent of patients rating the procedure as moderately or severely painful was significantly lower with VSC than with CC, both in less-experienced (19% vs 40%; p < 0.01) and experienced hands (15% vs 26%; p < 0.05). CONCLUSIONS: Our results indicated that VSC allows favorable examination compared with CC regarding completeness, time to cecal intubation, and comfort of patients undergoing unsedated colonoscopy, irrespective of the examiner's experience. These features suggest VSC as the preferred colonoscope for patients undergoing unsedated colonoscopy.     

Usefulness of a pediatric colonoscope for routine colonoscopy in women who have undergone hysterectomy

BACKGROUND: Colonoscopy can be difficult in some women who have undergone hysterectomy, which can be associated with a fixed, angulated sigmoid colon caused by postoperative pelvic adhesions. Our goal was to determine whether colonoscopy is easier and more comfortable for women after hysterectomy when performed with a pediatric colonoscope, which is thinner in diameter and more flexible than a standard "adult" colonoscope. METHODS: One hundred women with a history of hysterectomy undergoing outpatient colonoscopy were randomized in unblinded fashion to colonoscopy with a standard colonoscope (CF-100L or CF-Q140L, Olympus) or with a pediatric colonoscope (PCF-100, Olympus). All procedures were performed by a faculty endoscopist and timed. After examination, the endoscopist graded procedure difficulty, and patients were given a questionnaire that assessed their experience. RESULTS: The cecum was intubated more frequently in the pediatric colonoscope group than in the standard colonoscope group (96.1% vs. 71.4%, p < 0.001). Success increased in the standard colonoscope group to 89.8% when the pediatric colonoscope was used to complete the examination. There were no differences in the two groups in terms of mean total procedure times (21.4 minutes vs. 22.6 minutes), mean doses of meperidine administered (57 mg both groups), mean doses of midazolam administered (1.5 mg vs. 1.7 mg), scales of procedure difficulty as graded by the endoscopists, and comfort scales as graded by patients. For the cases in which the cecum was intubated, the mean time to reach the cecum (11.7 minutes for the pediatric colonoscope group vs. 12.7 minutes for the adult) was similar. CONCLUSIONS: The pediatric colonoscope is a reasonable choice for colonoscopy in women who have had a hysterectomy. Alternatively, if the endoscopist elects to start the procedure with a standard colonoscope, it is helpful to have a pediatric colonoscope available for use should a fixed, angulated sigmoid colon be encountered that cannot be easily or safely traversed with the standard colonoscope.     

Use of video and magnetic endoscope imaging for rating competence at colonoscopy: validation of a measurement tool

BACKGROUND: Counting the number of procedures performed provides at best a crude measure of technical competence in colonoscopy. The aim of this study was to develop and validate a qualitative and a quantitative score for measuring technical competency in colonoscopy using videotape evaluation. METHODS: Eighteen endoscopists with varying levels of experience were prospectively videotaped during colonoscope insertion. The following were recorded simultaneously: a closed circuit television view showing instrument handling, the endoscopic luminal view, and a continuous display of the colonoscope configuration (magnetic endoscope imaging). Videotapes were reviewed blindly and in random order by 3 experts. Performance in 3 categories was evaluated: (1) manipulation of instrument controls (0-10), (2) manipulation of the insertion tube (0-6) and (3) depth of insertion (0-4). A global assessment of competence was given for each endoscopist. RESULTS: Comparing the total scores as assessed by the 3 blinded experts, for each individual endoscopist, there were significant differences. However, there was good interobserver agreement and correlation between the individual scores and global assessment ratings of competence (p < 0.0001). CONCLUSIONS: The video assessment tool described appears to measure technical competence at colonoscopy, although in its present form it lacks reliability. Refinement of the score may improve reliability and deserves further evaluation.     

Colon anatomy based on CT colonography and fluoroscopy: Impact on looping,straightening and ancillary manoeuvres in colonoscopy

BackgroundUnsedated colonoscopy is an uncomfortable procedure for most patients. Discomfort during colonoscopy is largely related to looping of the colonoscope which displaces the colon from its native configuration. Therefore, complete intubation of the colon is considerably difficult in up to 10–20% of procedures. Aims of this study were to determine the “normal” colon anatomy in CT-colonoscopy with special focus on length, number of flexures and tortuosity and to assess frequency and type of looping as well as straightening manoeuvres based on fluoroscopic findings.Methods100 consecutive screening patients underwent CT colonography and another 100 cases traditional colonoscopy with fluoroscopic aid. Interactive 3D colon maps and 2D MPR images from virtual procedures were reviewed by two experienced GI-radiologists and GI-endoscopists. Colonoscopy was performed by three board-certified gastroenterologists. Fluoroscopic films of each case were recorded and retrospectively analysed.ResultsThere was a considerable difference in overall colonic length between CT colonography and conventional colonoscopy (167 cm vs. 93.5 cm). Number of acute angle flexures and degree of tortuosity was higher in CT colonography than previously assumed. The caecum was reached in 98/100 cases with conventional colonoscopy. Procedures were incomplete due to an obstructing sigmoid cancer and a floppy redundant colon. Looping occurred in 73/100 cases and straightening manoeuvres with fluoroscopy were highly effective in 95%. Looping was more common in older and smaller women.ConclusionsPredictive anatomical factors for potentially difficult endoscopic colonoscopy can be defined by CT colonography. Looping occurs frequently during routine colonoscopy but hindered caecal intubation in only one case. Short-term fluoroscopy is extremely helpful to guide straightening and ancillary manoeuvres and should be used selectively in patients with looping during conventional colonoscopy.