Use Of Magnetic Endoscope Imaging Research Articles

Preoperative localization of colorectal cancer: a systematic review and meta-analysis.

Preoperative colorectal tumor localization is crucial for appropriate resection and treatment planning. As the localization accuracy of conventional colonoscopy is considered to be low, several localization techniques have been developed. We systematically reviewed the tumor localization error rates of several preoperative endoscopic techniques and synthesized information on risk factors for localization errors and procedure-related adverse events. MEDLINE, EMBASE, the Cochrane Library, and the grey literature were searched. Studies were included if they reported tumor localization errors in patients with colorectal cancer undergoing resection with curative intent. Using random-effects models, pooled incidence of tumor localization errors were derived for conventional colonoscopy and colonoscopic tattooing. Due to the lack of comparative studies, a direct comparison of the pooled estimates was performed. Procedure-related adverse events, risk factors for localization errors, and the localization outcomes of other techniques such as colonoscopic clip placement, radioguided occult colonic lesion identification, and the use of magnetic endoscope imaging were also synthesized. A total of 38 non-randomized controlled and observational studies were included in this review (2578 patients underwent conventional colonoscopy and 643 colonoscopic tattooing). The pooled incidence of localization errors with conventional colonoscopy was 15.4% (95% CI 12.0-18.7), whereas that of colonoscopic tattooing was 9.5% (95% CI 5.7-13.3), mean difference 5.9% (95% CI 0.65-11.14, p=0.03). Adverse events secondary to tattooing were infrequent, and most were cases of ink spillage. Limited information was available for other localization techniques. Conventional colonoscopy has a higher incidence of localization error compared to colonoscopic tattooing for localization of colorectal cancer. Colonoscopic tattooing is safe and leads to fewer tumor localization errors. Given the widespread adoption of laparoscopic resections for colorectal cancer, routine colonoscopic tattooing should be adopted. However, studies directly comparing different localization techniques are needed.

Magnetic endoscope imaging for routine colonoscopy: impact on propofol dosage and patient safety - a randomized trial.

The use of magnetic endoscope imaging (MEI) has been previously shown to facilitate colonoscopy procedures. We aimed to evaluate the benefits of MEI in terms of reduction in propofol dosage in patients undergoing routine colonoscopy. We conducted a randomized prospective trial in a university hospital in Germany. Endoscopists were randomly assigned 1:1 to use MEI during colonoscopy (MEI arm) or to conduct colonoscopy without the use of MEI (standard arm). The desired level of sedation was conscious sedation as assessed using the Observer's Assessment of Alertness and Sedation scores. After complete recovery, patient satisfaction was assessed using a numeric rating scale (NRS) ranging from 1 to 10 points. The primary outcome was total propofol dosage. Secondary outcome measures were patient satisfaction, patients' cooperation, and complication rates, as well as cecal intubation time and adenoma detection. Among 334 randomized patients, no severe adverse events were observed. Median propofol dosage was significantly lower in the MEI arm compared with the standard arm (150 mg vs. 180 mg; P = 0.04). Deep sedation was observed in 7.8 % of patients in the MEI group and 3.6 % in the standard arm (P = 0.10). Patient satisfaction scores were higher in the MEI arm compared with standard procedures (9.0 vs. 8.5; P = 0.04). No significant differences in patients' cooperation, cecal intubation time, and adenoma detection were observed between the study arms. The use of MEI may be useful in reducing propofol dosage for colonoscopy and improving patient satisfaction.ClinicalTrials.gov identifier: NCT02121704.

Magnetic endoscopic imaging as an adjuvant to elective colonoscopy: a systematic review and meta-analysis of randomized controlled trials.

The use of magnetic endoscopic imaging (MEI) to visualize scope configuration in three dimensions is thought to increase procedural efficiency and diminish discomfort associated with colonoscopy. The aim of this systematic review and meta-analysis was to evaluate the performance of MEI in colonoscopy. The electronic databases Medline, EMBASE, and the Cochrane Library of Randomized Trials were searched. Methodological quality was assessed using the Jadad score. Odds ratios (OR) or risk differences for dichotomous variables and mean differences for continuous outcomes were calculated with 95 % confidence intervals (CIs). A total of 13 randomized studies met eligibility criteria and were included in qualitative and quantitative synthesis. MEI was associated with a significantly lower risk of failed cecal intubation (risk difference 4 %, 95 %CI 0 % - 7 %; P = 0.03), lower cecal intubation time (mean difference 0.58 minutes, 95 %CI 0.28 - 0.88; P < 0.001), and lower pain scores as estimated by visual analog scales (mean difference 0.45 cm, 95 %CI 0.03 - 0.86; P = 0.03) compared with conventional colonoscopy. On subgroup stratification of outcome according to endoscopist experience, failure rates were unaffected, but experienced colonoscopists reduced intubation times with MEI (mean difference 0.78 minutes, 95 %CI 0.12 - 1.43; P = 0.02). Sensitivity analyses of high-quality studies (Jadad score ≥ 3) showed no significant difference in failure rate (risk difference 4 %, 95 %CI 0 % - 8 %; P = 0.07) or intubation time (mean difference 0.56 minutes, 95 %CI - 0.15 to 1.28; P = 0.12). Adjuvant MEI is associated with a lower failure risk and shorter time to cecal intubation during elective colonoscopy compared with conventional colonoscopy.

Assessment of colonoscopy by use of magnetic endoscopic imaging: design and validation of an automated tool

Yield and safety of colonoscopy are highly dependent on operator competence. Existing tools for assessing competence is time-consuming and based on direct observation, making them prone for bias. There is a need for an easily accessible, reliable, and valid measure of endoscopic performance. The aim of this study was to develop and explore the validity of an automated, unbiased assessment tool. We tested 10 experienced endoscopists and 11 trainees in colonoscopy on a physical simulator (Kagaku Colonoscope Training Model). Participants were tested with an easy and a difficult case. Center for Clinical Education, Capital Region of Denmark. By using magnetic endoscopic imaging, we developed a colonoscopy progression score (CoPS). A pass/fail score was established by using the contrast-group method. We found significant differences in performance between the 2 groups using the CoPS in both case scenarios (easy: P< .001, difficult: P< .01). Small sample sizes. The heterogeneity of the experienced group resulted in a high passing score for the difficult case, which led to the failing of the less experienced in the group. The CoPS does not consider polyp detection rate, tissue damage, or patient discomfort. We developed a score of progression in colonoscopy, based on magnetic endoscopic imaging. With the same tool, a map of progression in colonoscopy can be provided. The CoPS and map of progression in colonoscopy could, with further development, be a valuable tool in colonoscopy training, providing live feedback and aid in unbiased certification.

Magnetic endoscopic imaging during colonoscopy is associated with less pain and decreased need of analgesia and sedation—Results from a randomized controlled trial

Objective. Colonoscopy is the method of choice for examining patients with lower gastrointestinal symptoms. The procedure is, however, in many cases, associated with pain and impaired compliance. Magnetic endoscopic imaging (MEI) generates a three-dimensional image of the colonoscope on a computer screen which may enable the colonoscopist to avoid looping, and consequently improve patient satisfaction. Material and methods. In this randomized controlled trial, 200 outpatients referred to colonoscopy at Østfold Hospital Trust, Fredrikstad, Norway, were included. Patients were randomized to either the standard arm (using fluoroscopy on demand, n = 100), or the MEI arm (n = 100). End points were time to cecum, subjective pain experiences, and use of sedation or analgesics. Results. Out of a total of 200 patients, 54% were men. However, no significant differences between the groups according to gender were found. Fluoroscopy was applied in 23% of the cases in the standard group. Use of MEI was associated with decreased time to cecum (p < 0.05), decreased pain scores (Visual Analogue Scale, p < 0.05), decreased need of analgesia (p < 0.01), and decreased amount of administered midazolam and pethidin (p < 0.05 in both). Conclusions.MEI during colonoscopy was associated with decreased pain and less on-demand requests for sedation and analgesia. In addition, the use of MEI reduced the cecal intubation time. Consequently the implementation of magnetic endoscopic imaging in the endoscopy suits may be beneficial, particularly in the clinically difficult cases.

Dynamic Position Change at Colonoscopy Improves Adenoma Detection

Colonoscopy has led the way with regard to quality assurance in gastroenterology and endoscopy services. Widespread adoption of colonoscopic screening and surveillance to detect colonic adenoma has driven much of the quality improvement. Improved bowel preparation regimens, better training of both trainees and trainers, optimizing withdrawal time of colonoscope to permit careful inspection, use of magnetic endoscopic imaging, better colonoscopies that now permit retroflexion in the right colon, regular and routine monitoring of colonoscopic performance and feedback, and single balloon-assisted colonoscopies in patients who failed conventional colonoscopy have all contributed to more efficient, effective and safer colonoscopies. Patient satisfaction with colonoscopy is high (1), and quality improvement driven by national guidelines and training has been encouraging (2). Dynamic position changes during colonoscope withdrawal was pioneered by the St Mark’s Hospital group from London, United Kingdom, and was incorporated into their training program. This group conducted a randomized crossover trial and reported that position changes during colonoscopic withdrawal significantly improved polyp and adenoma detection rates (3). In the current issue of the Journal, Koksal et al, from Turkey (4) (pages 509–512), confirmed this in a randomized study in which the investigators randomly assigned patients 1:1 to examination in either the left lateral position during colonoscope withdrawal or other positions (Table 1). An increase in adenoma detection rate of 9.8% in the transverse colon, splenic flexure, descending and sigmoid colon was noted in the group examined by dynamic position changes. TABLE 1 Dynamic patient positioning during colonoscope withdrawal (Koksal et al, pages 509–512) Dynamic position change is intuitive because air naturally rises to the highest position. Such position changes result in better distension with less insufflation of air, shifting of fluids and residues, and opening tight angles at flexures. Hence, this may also help ease insertion. However, the patients need to be lightly sedated and moving from the left lateral to supine position is relatively easy, but moving to the right lateral position is more cumbersome. It is possible that simply a ‘tilt’ to the right side rather than full right lateral decubitus may suffice, but this needs to be proven. Most Canadian colonoscopists do not routinely practice dynamic position changes at colonoscopy. On current evidence, a supportive case can be made for such practice to be adopted. This will also emphasize good practice during colonoscope withdrawal, not just in the time taken, but optimum positioning, carefully looking behind folds, optimizing luminal distension and suctioning all residues and fluid. While optimum insertion technique to reach the cecum makes a good colonoscopist, it is withdrawal technique that makes a great colonoscopist. Certainly, such meticulousness is not compatible with hurry, but the rewards are much greater, especially for the patient.

Magnetic endoscope imaging (ScopeGuide) elucidates the mechanism of action of the pain-alleviating impact of water exchange colonoscopy - attenuation of loop formation

The explanation why water exchange colonoscopy produces a significant reduction of pain during colonoscopy is unknown. A recent editorial recommended use of magnetic endoscope imaging (MEI) to elucidate the explanation. In unselected patients to show that MEI documents less frequent loop formation when water exchange is used. Observational, performance improvement. Veterans Affairs outpatient endoscopy. Routine colonoscopy cases. Colonoscopy using air or water exchange method was performed as previously described. The MEI equipment (ScopeGuide, Olympus) with built-in magnetic sensors displays the configuration of the colonoscope inside the patient. During sedated colonoscopy the endoscopist was blinded to the ScopeGuide images which were recorded and subsequently reviewed. Loop formation based on a visual guide provided by Olympus. There were 41 and 32 cases in the water exchange and air group, respectively. The sigmoid N loop was most common, followed by the sigmoid alpha loop, and exaggeration of scope curvature at the splenic flexure/transverse colon. Of these, 20/32 vs. 9/41 patients (p=0.0007) had sigmoid looping, and 17/32 vs. 9/41 patients (p=0.0007) had sigmoid/splenic looping when the scope tip was in the transverse colon, in the air and water exchange group, respectively. Colonoscopy method was not blinded and non randomized. MEI data objectively demonstrated significantly fewer loops during water exchange colonoscopy, elucidating its mechanism of pain alleviation - attenuation of loop formation. Since MEI feedback enhances cecal intubation by trainees, the role of MEI combined water exchange in speeding up trainee learning curves deserves further evaluations.

Magnetic Endoscopic Imaging Does Not Improve Unsedated Colonoscopy

In previous studies, magnetic endoscopic imaging (MEI) has not improved performance by experienced colonoscopists. However, use of MEI by trainees has reduced formation of loops in the colonoscope that can cause pain during the procedure and has …

Magnetic endoscopic imaging as a guide to smart colonoscopy

The enormous numbers of colonoscopies now performed worldwide make it more important than ever to optimize initial colonoscopy training and to develop a methodology for assessing the objective competence of endoscopists. At the early training stage only completion rate and the time taken to reach the cecum are the available end-points, which provide realistic but clear measures of actual skill, while perforation and potential mortality are cited as significant limitations of colonoscopy. Therefore, in the early days of colonoscopy the procedure was often performed with the use of fluoroscopy to visualize the endoscope.1 Today, fluoroscopy is reserved for exceptional cases due to the added expense, inconvenience and radiation risk it presents, both to the patient and the medical staff. As a consequence generations of endoscopists have remained unaware of the potential advantages that imaging of the endoscope configuration offers when compared to the blind insertion of the endoscope. Loop recognition, management and straightening are all important aspects of quality colonoscopy. Loops are easier to understand and reduced when displayed on a screen, rather than by guessing and by feel alone. While it is a bonus for trainees and certainly for the patient to have the teacher standing alongside, a long apprenticeship phase and the 100–300 subsequent solo procedures needed to achieve supposed competence are also costly for the hospital and the supervising endoscopist (C. Williams 2011, pers. comm.). In 1993 magnetic endoscope imaging (MEI) was first presented as an alternative to fluoroscopy.2 MEI is derived from very low-strength magnetic fields generated by a series of tiny wire coils positioned along the length of the colonoscope. It provides real-time three-dimensional views of the colonoscope shaft configuration and its location within the abdomen on a separate computer monitor. Several studies have shown that MEI reliably permits the exact localization of colonic pathologies.3-5 Thus, it can be used for follow-up examination after local treatment or in patients with small colorectal tumors for whom surgery is planned. Although initial studies suggested that the use of the MEI could also improve the performance of both skilled and trainee endoscopists allowing a higher colonoscopy completion rate,6 only a few further randomized trials have been reported in the literature and showed conflicting results with regard to intubation times and rates as well as the need for sedatives and the pain experienced by the patient.3, 7-9 Moreover, most of these studies did not include enough patients to gain enough statistical power to show the difference between the groups who do and do not use MEI. In this issue of the Journal of Digestive Diseases Dechêne et al. present the largest study evaluating the use of MEI for colonoscopy done to date and add valuable information about the utility of MEI.10 With the inclusion of 1000 patients results are reliable. The authors found that the use of MEI did not accelerate cecal intubation times. However, the duration of abdominal compression was significantly shorter and the intensity of abdominal compression was lower in MEI-guided colonoscopy. Moreover, fewer turn maneuvers per patient were needed in the group with MEI. This depicts what MEI is able to offer for colonoscopy in the era of potent analgosedation. MEI facilitates the technical performance of colonoscopy by showing what is really going on inside the patient. Endoscope looping and the effects of rotation and withdrawal can be directly observed. Further, MEI permits the precise and effective administration of external abdominal compression. On the other hand, cecal intubation rates and times are rather dependent on adequate bowel preparation and the use of sedatives allowing the insertion of the endoscope even in the presence of normally painful stretching of the colon.11 Nevertheless, the personal aim of each endoscopist should be the exertion of the optimal technique, for example, by the use of MEI, thereby keeping the use of sedatives low. Given the obvious advantages of the application of a safe endoscope imaging method the question arises why MEI has not been used in every endoscopy unit so far. Indeed, most endoscopists consider that the benefits of MEI are not big enough to compensate for the additional costs for the special equipment and colonoscopes. Here, the manufacturer would have to concede. For the endoscopist MEI is finally like all the other small things that make life easier: once you have used it, you would not like to not to have it.

Technical Advances in Getting to the Cecum

Clinical demand for colonoscopy has increased with the introduction of colorectal cancer screening worldwide. The goal is a complete, comfortable, and high-quality procedure. Up to one third of colonoscopies are challenging, and incomplete colonoscopy occurs in 10% of cases. High cecal intubation rates can be achieved by minimizing air insufflation and looping, and by using ancillary maneuvers such as position change and abdominal pressure. In difficult cases, changing to a non-standard endoscope, the use of magnetic endoscopic imaging, and endoscopic accessories including a transparent cap or an overtube can be an effective measure. The use of carbon dioxide instead of air insufflation reduces post-procedure discomfort. A new technique involving water immersion in lieu of air insufflation may reduce discomfort and facilitate insertion to the cecum. Data from alternative novel colonoscopy platforms including capsule colonoscopy, Neoguide, Invendoscope, and the Aer-O-scope appear promising, and prospective clinical studies are warranted.

Early Use of Magnetic Endoscopic Imaging by Novice Colonoscopists: Improved Performance without Increase in Workload

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

The usefulness of a magnetic endoscope locating device in colonoscopy in daily practice: a prospective case-controlled study

This study aimed to investigate the effects of magnetic endoscope imaging (MEI) regarding examination time, caecal intubation rate, and sedation and analgesic requirements during routine colonoscopy compared with earlier used X-ray imaging. Consecutive outpatients undergoing colonoscopy were prospectively studied for two periods. In the first period X-ray was used to establish the correct position of the endoscope. In the second period MEI was used. Outcome measures were examination time, caecal intubation rate, median dose of analgesic and sedative administered, and median X-ray dose used. The two groups studied were comparable with regards to age, sex, and number of therapeutic examinations. The examination time was significantly shorter with use of MEI (median 29 min versus 43 min). No significant differences in the use of analgesic and sedative were found (median 50 microg phentanyle and 2 mg midazolam in both groups). Median X-ray dose was 150 cGy in the group using X-ray imaging. MEI is the imaging methodology of choice and should always be available in colonoscopy, especially for precise locating of colonic lesions.

Improvement in caecal intubation rate and pain reduction by using 3-dimensional magnetic imaging for unsedated colonoscopy: A randomized trial of patients referred for colonoscopy

Objective. Use of magnetic endoscope imaging (MEI) during colonoscopy has the potential to ease caecal intubation and patient discomfort and to reduce dependence on sedation and/or analgesics (SAs). However, pain reduction by using MEI has not been demonstrated so far, probably because of the liberal use of SAs. The aim of the present study was to evaluate the effect of MEI on caecal intubation and patient pain during unsedated colonoscopy performed by experienced and inexperienced colonoscopists. Material and methods. A consecutive series of outpatients referred for colonoscopy were randomly allocated to examination with (imager group) or without (standard group) the use of MEI. Patients agreeing to SAs being given only on demand were included in the study. End-points were caecal intubation and pain, the latter to be graded by category on a form to be completed on the day after the examination. Results. The proportion of colonoscopies performed without SAs was similar when comparing imager and standard groups and experienced with inexperienced colonoscopists; altogether 367(88%) out of 419 colonoscopies. The caecal intubation rate was higher in the imager group (190/212 (90%)) than in the standard group (153/207(74%)) (p<0.001), both collectively and separately for experienced and inexperienced colonoscopists. A pain-reducing effect of MEI was shown only when performed by experienced colonoscopists, with severe pain in 10/137 patients (7.3%) in the imager group and 21/132 patients (16%) in the standard group (p=0.03). Conclusions. In colonoscopy without the routine use of SAs, MEI significantly improves the caecum intubation rate and reduces pain during the procedure.

Improvement in Colonoscopy Performance with Adjunctive Magnetic Endoscope Imaging: A Randomized Controlled Trial

Although magnetic endoscope imaging (MEI) has been reported to improve the performance of colonoscopy, so far only a few randomized controlled studies have been published supporting its adjunctive role. This randomized study was designed to evaluate the role of MEI on the overall performance of colonoscopy. Patients admitted for elective colonoscopy were recruited. They were randomly allocated into two groups, either with an MEI view (study group) or without (control group). Examinations were performed by one of the two designated, trained endoscopists. The primary end point was intubation time. Other outcome measures included completion rate, pain score graded by patients, and ease of procedure as reflected by the number of attempts at straightening the scope, the number of times of hand pressure was applied abdominally, and the need to change the patient's position. Endoscopists were also asked to score the ease of procedure. Finally, in the MEI group, endoscopists were asked to comment on whether MEI helped to locate colonic lesions during endoscopy. In a 12-month period, 120 patients were recruited, with 60 patients in each group. The two groups were matched for age, gender distribution, and indications for colonoscopy. No complication occurred in either group. No significant difference was observed in the intubation time and colonoscopy completion rate. Other measures of ease of procedure and pain score were also similar. However, MEI was reported by endoscopists to be helpful in locating colonic lesions in 32 % of examinations with positive findings. For trained endoscopists, the device confers no benefit in terms of performance improvement. The only identified benefit is in locating lesions. Thus, while the routine use of MEI cannot be recommended, the device could be selectively offered to patients for follow-up examination after local treatment, or to patients with small colorectal tumors in whom laparoscopic surgery is planned.

Patient pain during colonoscopy: an analysis using real-time magnetic endoscope imaging.

Colonoscopy is generally perceived as being a painful procedure. Contributory factors are: stretching of the colonic wall and mesenteric attachments from looping of the instrument shaft, overinsufflation, the degree of torque or force applied to the colonoscope shaft, and patient pain threshold. The aim of this study was to determine the frequency of pain episodes experienced during diagnostic colonoscopy and the corresponding colonoscope configuration, utilizing real-time magnetic endoscope imaging (MEI). Consecutive outpatients undergoing colonoscopy were studied. Patients with previous colonic resections were excluded. Procedures were commenced with antispasmodics only, and patient sedation was self-administered whenever significant discomfort was experienced, using a patient-controlled analgesia (PCA) syringe pump. All "demands" were correlated with the MEI record, which was subsequently analysed. A total of 650 demands were recorded in 102 patients. Seventy-seven percent of all demands occurred with the colonoscope tip in the sigmoid colon, 7 % in the descending colon, 6 % at the splenic flexure, 5 % in the transverse colon, and 4 % in the proximal colon. Ninety percent of all pain episodes coincided with either looping (79 %) or straightening of the colonoscope shaft (11 %); presumed overinsufflation being an infrequent cause of pain (9 %). Of the loops encountered during colonoscopy, the N-sigmoid spiral loop was associated with the majority of pain episodes (56 %). Looping was both more frequent ( P = 0.0002) and less well tolerated in women than in men ( P = 0.0140). This study is the first to document pain at colonoscopy accurately. Looping, particularly in the variable anatomy of the sigmoid colon, is the major cause of pain, especially in women. Use of MEI may improve pain control by facilitating the straightening of loops within the sigmoid colon, and by enabling the endoscopist to target patient analgesia.