A preliminary prospective study of the usefulness of a magnetic endoscope locating device during colonoscopy

Accuracy of preoperative tumor localization in large bowel using 3D magnetic endoscopic imaging: randomized clinical trial

Background

Laparoscopic surgery has become the standard treatment for colorectal cancer. A tumor that does not involve serosa is invisible intraoperatively, and manual palpation of the tumor during laparoscopy is not possible. Therefore, accurate localization of the neoplastic infiltrate remains one of the most important tasks prior to elective laparoscopic surgery. The aim of this study was to evaluate the utility of a magnetic endoscopic imaging (MEI) for precise preoperative endoscopic localization of neoplastic infiltrate within the large bowel.

Materials and methods

The study enrolled 246 patients who underwent elective surgery for colorectal cancer in 2012–2015 with accurate preoperative colonoscopic localization of the tumor. The analysis concerned patients with neoplastic infiltrate localized more than 30 cm from the anal verge. For evaluative purposes and accuracy of localization, the intestine was divided anatomically into 13 parts. Colonoscopic examinations were conducted with two types of endoscopes: group I—with MEI and group II—without MEI. Patients were assigned to the groups by random allocation. Ultimate confirmation of the tumor localization was accomplished by intraoperative evaluation.

Results

Group I involved 127 patients and group II 129. The two groups were compared in terms of age, sex, BMI and frequency of previous abdominal procedures. Proper localization of the lesion was confirmed in 95.23 % of group I patients and in 83.19 % of group II patients (p < 0.05). The greatest discrepancy in localization occurred in 8.9 % of patients from group I and 20 % of patients from group II in which the lesion was assessed primarily in the distal sigmoid.

Conclusions

A magnetic endoscopic imaging allows more accurate localization of neoplastic infiltrate within the large intestine compared to standard colonoscopy alone, especially within the sigmoid colon. This method can be particularly useful in planning and performing laparoscopic procedures to diminish the likelihood of improper bowel segment resection.

ClinicalTrials.gov number

NCT01688557

Electronic supplementary material

The online version of this article (doi:10.1007/s00464-016-5203-4) contains supplementary material, which is available to authorized users.

Mechanical analysis of insertion problems and pain during colonoscopy: why highly skill-dependent colonoscopy routines are necessary in the first place... and how they may be avoided

BACKGROUND

Colonoscopy requires highly skill-dependent manoeuvres that demand a significant amount of training, and can cause considerable discomfort to patients, which increases the use of sedatives. Understanding the underlying fundamental mechanics behind insertion difficulties and pain during colonoscopy may help to simplify colonoscopy and reduce the required extent of training and reliance on sedatives.

METHODS

A literature search, anatomical studies, models of the colon and colonoscope, and bench tests were used to qualitatively analyze the fundamental mechanical causes of insertion difficulties and pain. A categorized review resulted in an overview of potential alternatives to current colonoscopes.

RESULTS

To advance a colonoscope through the colon, the colon wall, ligaments and peritoneum must be stretched, thus creating tension in the colon wall, which resists further wall deformation. This resistance forces the colonoscope to bend and follow the curves of the colon. The deformations that cause insertion difficulties and pain (necessitating the use of complex conventional manoeuvres) are the stretching of ligaments, and stretching of colon wall in the transverse and longitudinal directions, and the peritoneum.

CONCLUSIONS

Four fundamental mechanical solutions to prevent these deformations were extracted from the analysis. The current results may help in the development of new colonoscopy devices that reduce - or eliminate - the necessity of using highly skill-dependent manoeuvres, facilitate training and reduce the use of sedatives.

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.

Evaluation of magnetic scope navigation in screening endoscopic examination of colorectal cancer

Background

Colorectal cancer is the most common cancer in Europe. Early diagnosis and treatment gives the patient a chance for complete recovery. Screening colonoscopies in the symptom-free patients are currently performed on a wide scale. The examinations are performed under local anesthesia which does not eliminate all discomfort and pain related to the examination. The aim of this study was to evaluate magnetic scope navigation in screening endoscopic examinations performed to detect early-stage colorectal cancer.

Methods

The study group consisted of 200 patients, aged 40–65 years, who were free from colon cancer symptoms. All patients underwent complete colonoscopy under local anesthesia. The equipment could be fitted with the scope that allows three-dimensional observation of instrument localization in the bowel. The examination was performed by three experienced endoscopists, each of whom performed over 5,000 colonoscopies. The patients were randomized to two groups: those whose equipment did not have 3D navigation (group I) and those whose equipment did have 3D navigation (group II). Each group consisted of 100 cases matched by gender, age, and BMI. The authors compared the duration of introducing instrument to cecum, the pulse rate before the examination and at the time the instrument reached the cecum, and subjective pain evaluation by the patient on the visual analog scale.

Results

Group I consisted of 54 women and 46 men with a mean age of 54.6 years and mean BMI of 27.8 kg/m², and group II had 58 women and 42 men, mean age of 55.1 years and mean BMI of 26.4 kg/m². The average time it took for the instrument to reach the cecum was 216s in group I and 181s in group II (P < 0.05). Pain measured on the 10-point VAS scale was 2.44 in group I and 1.85 in group II (P < 0.05). The results showed a significantly shorter time for the instrument to reach the cecum in group II and significantly lower pain intensity during the examination was reported by the group II patients. No significant differences were found in the pulse measurements between the groups (P = 0.5).

Conclusions

3D navigation during colonoscopy decreases the time for the instrument to reach the cecum and lowers pain intensity subjectively reported by the patients. The use of 3D and the possibility to observe instrument localization and maneuvers brings more comfort to the patients.

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.&nbsp;

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.

Determining scope position during colonoscopy without use of ionizing radiation or magnetic imaging: the enhanced mapping ability of the NeoGuide Endoscopy System

BACKGROUND

Knowledge of the position and shape of the endoscope could overcome many challenges of performing colonoscopy, e.g., loop formation. A novel computer-assisted colonoscope (NeoGuide Endoscopy System) delivers a real-time, three-dimensional map of the tip position and insertion tube shape in addition to the video image of the colon lumen. The aim of this study is to evaluate the mapping capabilities of the NeoGuide Endoscopy System in terms of colonic looping, insertion depth, tip position, and tip angle formation.

METHODS

Ten endoscopists with various levels of experience were each shown 70 map images generated by the NeoGuide endoscopy system in a benchtop anatomical colon model. First endoscopists were asked to determine the tip angle based on the map image and the system's corresponding tip positioning aid (20 images). In the second part they had to identify the scope-tip position in the colon model (40 images). In the third part ten images were presented for identification of colonic loops.

RESULTS

The tip angle was correctly identified in 99% (198/200) of images. Using only the map images the scope position was accurately determined in 87.5% (350/400). Identification of colonic looping of the scope was appropriate in 99% (99/100). Overall accuracy was 92.4%, and overall positive predictive value was 94.9%.

CONCLUSION

Three-dimensional map images generated by the NeoGuide endoscopy system provide accurate information regarding tip position, insertion tube position, and colonic looping.

Use of an electromagnetic colonoscope to assess maneuvers associated with cecal intubation

Background

Safe and effective colonoscopy is aided by the use of endoscopic techniques and maneuvers (ETM) during the examination including patient repositioning, stiffening of the endoscope and abdominal pressure.

Aim

To better understand the use and value of ETM during colonoscopy by using a device that allows real-time imaging of the colonoscope insertion shaft.

Methods

The use of ETM during colonoscopy and their success was recorded. Experienced colonoscopists and endoscopy assistants used a commercially available electromagnetic (EM) transmitter and a special adult variable stiffness instrument with 12 embedded sensors to examine 46 patients. In 5 of these a special EM probe passed through the instrument channel of a standard pediatric variable stiffness colonoscope was used instead of the EM colonoscope.

Results

Thirty-nine men and 7 women with a mean age of 64 years (range 33–90) were studied. The cecum was intubated in 93.5% (43/46). The mean time to reach the cecum was 10.6 minutes (range 3–25). ETM were used a total of 174 times in 41 of the patients to assist with cecal intubation. When ETM were required to reach the cecum, and the cecum was intubated, an average of 3.82 ETM/patient was used. While ETM were used most often when the tip of the colonoscope was in the left side of the colon (rectum 5.0%, sigmoid colon 20.7%, descending colon 5.0%, and splenic flexure 11.6%), when the instrument was in the transverse colon (14.8%), hepatic flexure (20.7%) and ascending colon (19.8%) the use of ETM was also required. When the colonoscope tip was in the transverse colon, hepatic flexure and ascending colon, ETM success rates were less (61.1%, 52.0%, and 41.7% respectively) compared to the left colon success rates (rectum 83.3%, sigmoid colon 84.0%, descending colon 100%, and splenic flexure 85.7%).

Conclusion

The EM colonoscope allows imaging of the insertion shaft without fluoroscopy and is a useful device for evaluating the efficacy of ETM. ETM are important tools of the colonoscopist and are used most often in the left colon where they are most effective.