A transparent hood simplifies magnifying observation of the colonic mucosa by colonoscopy

Distal Endoscopic Attachments

Endoscopy is an evolving science and the last two decades has seen it expand exponentially at a pace unapparelled in the past. With the advancement in new procedures like image-enhanced endoscopy, magnifying endoscopy, third space endoscopy, and highly advanced endoscopic ultrasound procedures, endoscopic accessories are also evolving to cater the unmet needs. Endoscopic cap or distal attachment cap is a simple but very important accessory in the endoscopists' armamentarium which has changed the path of endoscopic procedures. It has so far been used commonly mostly for variceal ligation and endoscopic mucosal resections for colorectal polyps. But the horizon of its use has expanded in the recent years for difficult clinical scenarios like providing stability to the endoscope, overcoming blind spots during screening colonoscopies, maintaining clear field of vision during endotherapy of gastrointestinal bleeding, and during magnification endoscopy for lesion characterizations and so on. These caps are of different shapes, sizes, colors, and material depending on manufacturers and their implications while performing varied endoscopies. This review summarizes the clinical utilities of the cap in diagnostic as well as therapeutic endoscopy and its expanding indications of use.

Indications and outcomes of endoscopic resection for non-pedunculated colorectal lesions: A narrative review

In the last years, endoscopic techniques gained a crucial role in the treatment of colorectal flat lesions. At the same time, the importance of a reliable assessment of such lesions to predict the malignancy and the depth of invasion of the colonic wall emerged. The current unsolved dilemma about the endoscopic excision techniques concerns the necessity of a reliable submucosal invasive cancer assessment system that can stratify the risk of the post-procedural need for surgery. Accordingly, this narrative literature review aims to compare the available diagnostic strategies in predicting malignancy and to give a guide about the best techniques to employ. We performed a literature search using electronic databases (MEDLINE/PubMed, EMBASE, and Cochrane Library). We collected all articles about endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) registering the outcomes. Moreover, we analyzed all meta-analyses comparing EMR vs ESD outcomes for colorectal sessile or non-polypoid lesions of any size, preoperatively estimated as non-invasive. Seven meta-analysis studies, mainly Eastern, were included in the analysis comparing 124 studies and overall 22954 patients who underwent EMR and ESD procedures. Of these, eighty-two were retrospective, twenty-four perspective, nine case-control, and six cohorts, while three were randomized clinical trials. A total of 18118 EMR and 10379 ESD were completed for a whole of 28497 colorectal sessile or non-polypoid lesions > 5-10 mm in size. In conclusion, it is crucial to enhance the preoperative diagnostic workup, especially in deciding the most suitable endoscopic method for radical resection of flat colorectal lesions at risk of underlying malignancy. Additionally, the ESD necessitates further improvement because of the excessively time-consuming as well as the intraprocedural technical hindrances and related complications. We found a higher rate of en bloc resections and R0 for ESD than EMR for non-pedunculated colorectal lesions. Nevertheless, despite the lower local recurrence rates, ESD had greater perforation rates and needed lengthier procedural times. The prevailing risk for additional surgery in ESD rather than EMR for complications or oncologic reasons is still uncertain.

Novel 3D-printing technique for caps to enable tailored therapeutic endoscopy

BACKGROUND AND AIM

To evaluate the feasibility of a tailored endoscopic cap created using 3D-printing technology that is customized according to esophagogastric lesions of each patient.

METHODS

Tailored endoscopic caps, which were designed and fabricated with a 3D printer, were inserted in 35 patients. The types of cap were side-hole cap made for cap-assisted endoscopic mucosal resection (EMRC), oblique-head cap designed for endoscopic submucosal dissection (ESD), wide-head cap used for Trucut biopsy (TCB), and narrow-tip cap to facilitate peroral endoscopic myotomy (POEM).

RESULTS

EMRC in the esophagus and gastroesophageal junction was carried out using a side-hole cap in seven patients. Median total procedure time for successful removal of lesions was 14 min (range 8-50 min). Gastric ESD was carried out using with an oblique-head cap in 16 patients, for which the median total procedure time was 53 min. TCB in the esophagus was done using a wide-head cap in eight patients. While carrying out POEM for tunneling, a narrow-tip cap was used in four patients with achalasia.

CONCLUSION

Based on the current proof-of-concept study, we anticipate that creating a tailored endoscopic cap is feasible for therapeutic endoscopy.

Correlation between number of polyps detected per colonoscopy and polyp detection rate in average risk Chinese population of colorectal cancer

AIM: To assess the association between the number of polyps detected per colonoscopy (PPC) and polyp detection rate (PDR).

METHODS: A retrospective analysis was performed of the data for patients who underwent screening colonoscopy in the Digestive Endoscopic Center of Changhai Hospital between March 2010 and February 2013. PDR and PPC were calculated by gender, age and endoscopist. Linear regression analysis was applied to study the relationship between PDR and PPC.

RESULTS: A total of 1928 subjects received complete colonoscopies. There were significant linear correlations between PDR and PPC by age in both genders (men: r = 0.96, P = 0.0092; women: r = 0.97, P = 0.0059). There was also a significant linear correlation by endoscopist (r = 0.88, P < 0.05).

CONCLUSION: There is a significant correlation between PDR and PPC. PPC can act as a supplementary index to help distinguish endoscopists who have different colonoscopy skills.

Spatial orientation in pathway surgery

BACKGROUND

In the field of minimally invasive surgery, specifically in pathway surgery (i.e. minimal invasive procedures carried out transluminally or through instrument-created pathways), spatial disorientation is a common experience to endoscopists. In this article, two effects that may cause spatial disorientation in pathway surgery, 'control-display compatibility' and 'local disorientation', were studied.

METHOD

A custom-developed simulator Endo-PaC was developed and used for mimicking pathway surgical scenarios. In Study 1, two ways of control-display alignment, normal mapping and mirrored mapping, were tested in combination with two control devices, thumb control and wrist control, in an orienting task using Endo-PaC. In Study 2, a tethered viewpoint was added to the virtual instrument tip. It was hypothesized that the visible tip would provide a cue of orientating direction in the reference frame during the instrument navigation. In both studies, novice participants were involved, and their performance was evaluated with regard to task time, path length travelled by the virtual tip, time and number of warnings, and subjective workload and personal preference.

RESULTS

In Study 1, normal-thumb and normal-wrist mapping yielded significantly lower means than mirrored-thumb and mirrored-wrist control for all investigated objective and subjective performance measurements. Out of 24 participants, 20 participants preferred normal control mapping. In Study 2, participants performed the task in shorter time and with shorter path length when the tip was visible tip on the monitor using a tethered viewpoint, but with a lower number and time of warnings without a visible tip.

CONCLUSION

The results of our studies show that eliminating the visual-display misalignment would greatly improve novice participants' performance, reduce the training time and their cognitive workload. A visible tip on the monitor would provide strong direction cue and shorten the performance time, but might introduce collision errors to novices and therefore requires longer training time.

Usefulness of cap-assisted colonoscopy during colonoscopic EMR: a randomized, controlled trial

BACKGROUND

Clinical demand for total colonoscopy is increasing. Several articles have reported on the usefulness of a cap for faster cecal intubation and reduced patient discomfort, but results for polyp and adenoma detection have been inconsistent.

OBJECTIVE

To assess the efficacy of a cap attached to the tip of a colonoscope for detection and resection of polyps by experienced colonoscopists.

DESIGN

Prospective, randomized, controlled trial.

SETTING

A tertiary referral center.

PATIENTS AND INTERVENTION

A total of 329 patients who underwent colonoscopic EMR were randomized to cap-assisted colonoscopy (CAC) (CAC group, n = 166) or regular colonoscopy (RC) (RC group, n = 163).

MAIN OUTCOME MEASUREMENTS

Cecal intubation time, total procedure time, required time for colonoscopic EMR of each polyp, and missing polyp rate.

RESULTS

The cecal intubation time in the CAC group and RC group was 5.3 ± 3.3 minutes and 5.8 ± 3.7 minutes, respectively (P = .170). The total procedure time in the CAC group and RC group was 23.0 ± 15.5 minutes and 29.2 ± 13.4 minutes, respectively (P = .626). The time required for colonoscopic EMR of each polyp in the CAC group and RC group was 3.5 ± 4.5 minutes and 4.2 ± 5.1 minutes, respectively (P = .010). The number of polyps during the initial colonoscopy in the CAC group and RC group was 2.2 ± 1.7 and 2.0 ± 1.8, respectively (P = .221). The number of detected polyps during colonoscopic EMR in the CAC group and RC group was 3.4 ± 2.7 and 2.7 ± 1.9 (P = .003). The number of missed polyps in the CAC group and RC group was 1.1 ± 1.5 and 0.8 ± 0.9 (P = .024).

LIMITATION

Single-center experience.

CONCLUSIONS

CAC may reduce the time required for colonoscopic EMR of each polyp and may also improve the polyp detection rate.

Impact of a transparent hood on the performance of total colonoscopy: a randomized controlled trial

BACKGROUND

Clinical demand for total colonoscopy (TCS) is increasing. Improvement of the cecal intubation rate and shortening of the examination time would expand the capacity for TCS.

OBJECTIVE

To assess the efficacy of a transparent hood attached to the tip of a colonoscope for cecal intubation in TCS.

DESIGN

Prospective, randomized, controlled study.

SETTING

Single tertiary-referral center.

INTERVENTIONS

TCS.

MAIN OUTCOME MEASUREMENTS

Cecal intubation time and rate, complications, patient discomfort, and detection rate of colonic polyps.

METHODS

Patients who were to undergo screening and/or surveillance TCS for colorectal cancer were invited to participate in the study. Cecal intubation time and rate, complications, patient discomfort, and detection rate of colonic polyps were evaluated.

RESULTS

A total of 592 patients enrolled in this study were randomly allocated to the hood group and no-hood group. The mean (SD) cecal intubation time in the hood group and the no-hood group was 10.2 +/- 12.5 minutes and 13.4 +/- 15.8 minutes, respectively (P = .0241). The effect of its use was more prominent in the expert endoscopists group compared with those with moderate experience. The cecal intubation rate and the detection rate of small polyps in the 2 groups were similar. The grade of patient discomfort was significantly lower in the hood group. No complications were encountered with the use of the hood.

CONCLUSIONS

Use of a transparent hood on the tip of a colonoscope shortened the time required for cecal intubation and decreased patient discomfort; such use was more effective among experts in shortening the examination time.

[Colonic polyps diagnosis by conventional video colonoscopes and chromoscopy with indigo carmine dye solution]

BACKGROUND

Magnification colonoscopy and contrast chromoscopy with indigo carmine dye solution have been used to differentiate neoplastic polyps (adenomas and adenocarcinomas) from non-neoplastic (hyperplastic, inflammatory, juvenile) in an attempt to obviate endoscopic polypectomy. On the other hand, little published information exists concerning conventional video colonoscopes and chromoscopy for polyp histology prediction. Aim - To assess usefullness of conventional video colonoscopes and contrast chromoscopy with indigo carmine solution for differential diagnosis of colon polyps.

METHODS

In a routine colonoscopy series, we performed chromoscopy with conventional video colonoscopes before endoscopic excision of detected polyps. If a sulcus pattern was observed on the surface of the lesion, it was classified as neoplastic. Polyps were classified as non-neoplastic if no sulcus was detected on its surface. These observations were then compared with histology.

RESULTS

In the study period (18 months), we detected 133 polyps in 53 patients. We were able to compare results of histology and chromoscopy in 126 lesions. The sensitivity, specificity, diagnostic accuracy, negative predictive value, and positive predictive value were 56,4%, 79,2%, 65,1%, 52,8%, and 81,5%, respectively.

CONCLUSION

On the base of the presented data, we concluded that conventional video colonoscopes and contrast chromoscopy with indigo carmine solution is not a good technique for differential diagnosis of colon polyps.