Incomplete colonoscopy: maximizing completion rates of gastroenterologists

MorphGI: A Self-Propelling Soft Robotic Endoscope Through Morphing Shape

Colonoscopy is currently the best method for detecting bowel cancer, but fundamental design and construction have not changed significantly in decades. Conventional colonoscope (CC) is difficult to maneuver and can lead to pain with a risk of damaging the bowel due to its rigidity. We present the MorphGI, a robotic endoscope system that is self-propelling and made of soft material, thus easy to operate and inherently safe to patient. After verifying kinematic control of the distal bending segment, the system was evaluated in: a benchtop colon simulator, using multiple colon configurations; a colon simulator with force sensors; and surgically removed pig colon tissue. In the colon simulator, the MorphGI completed a colonoscopy in an average of 10.84 min. The MorphGI showed an average of 77% and 62% reduction in peak forces compared to a CC in high- and low-stiffness modes, respectively. Self-propulsion was demonstrated in the excised tissue test but not in the live pig test, due to anatomical differences between pig and human colons. This work demonstrates the core features of MorphGI.

A review on model-based and model-free approaches to control soft actuators and their potentials in colonoscopy

Colorectal cancer (CRC) is the third most common cancer worldwide and responsible for approximately 1 million deaths annually. Early screening is essential to increase the chances of survival, and it can also reduce the cost of treatments for healthcare centres. Colonoscopy is the gold standard for CRC screening and treatment, but it has several drawbacks, including difficulty in manoeuvring the device, patient discomfort, and high cost. Soft endorobots, small and compliant devices thatcan reduce the force exerted on the colonic wall, offer a potential solution to these issues. However, controlling these soft robots is challenging due to their deformable materials and the limitations of mathematical models. In this Review, we discuss model-free and model-based approaches for controlling soft robots that can potentially be applied to endorobots for colonoscopy. We highlight the importance of selecting appropriate control methods based on various parameters, such as sensor and actuator solutions. This review aims to contribute to the development of smart control strategies for soft endorobots that can enhance the effectiveness and safety of robotics in colonoscopy. These strategies can be defined based on the available information about the robot and surrounding environment, control demands, mechanical design impact and characterization data based on calibration.

Three-dimensional reconstruction of computed tomography colonography discloses anatomic features associated with colonoscopy failure

Objectives:

Three-dimensional virtual reality (3D VR) permits precise reconstruction of computed tomography (CT) images, and these allow precise measurements of colonic anatomical parameters. Colonoscopy proves challenging in a subset of patients, and thus CT colonoscopy (CTC) is often required to visualize the entire colon. The aim of the study was to determine whether 3D reconstructions of the colon could help identify and quantify the key anatomical features leading to colonoscopy failure.

Design:

Retrospective observational study.

Methods:

Using 3D VR technology, we reconstructed and compared the length of various colonic segments and number of bends and colonic width in 10 cases of CTC in technically failed prior colonoscopies to 10 cases of CTC performed for non-technically failure indications.

Results:

We found significant elongation of the sigmoid colon (71 ± 23 cm versus 35 ± 9; p = 0.01) and of pancolonic length (216 ± 38 cm versus 158 ± 20 cm; p = 0.001) in cases of technically failed colonoscopy. There was also a significant increase in the number of colonic angles (17.7 ± 3.2 versus 12.7 ± 2.4; p = 0.008) in failed colonoscopy cases.

Conclusion:

Increased sigmoid and pancolonic length and more colonic bends are novel factors associated with technical failure of colonoscopy.

Can endoscopic follow-up after acute diverticulitis be rationalised?

BACKGROUND

Acute diverticulitis (AD) is a common cause of presentation to emergency surgical services. Follow-up with endoluminal investigation to exclude colorectal cancer (CRC) remains controversial. Guidelines are increasingly moving to a more restrictive follow-up based on severity of disease and age. The purpose of this observational study was to assess the prevalence of CRC in AD patients and the impact of follow-up on endoscopy services.

METHODS

Patients admitted with a diagnosis of AD over a 2-year period were reviewed. The proportion of patients undergoing endoscopic follow-up and the CRC detection rate were recorded. The potential impact of a more conservative approach to follow-up was evaluated.

RESULTS

There were 484 patients with AD presenting 546 times (M:F = 198:286; median age = 63 years). 80% of admissions were aged 50 or older. There were 43 emergency interventions in 39 patients (10 percutaneous drain; 33 surgery). The remainder were managed conservatively. 28 patients (5.1%) underwent colonic resection with cancer found in one specimen (3.6%). 287 patients underwent endoluminal follow-up with cancer diagnosed in 3 cases (1.0%). There was no significant difference in the prevalence of CRC between patients requiring emergency surgery and those managed conservatively, or between patients with complicated versus uncomplicated diverticulitis.

CONCLUSION

CRC masquerading as acute diverticulitis is rare. The incidence of neoplasia both at endoscopic follow-up and in patients requiring emergency intervention is low. Conservative follow-up strategies appear safe, but their effectiveness in reducing the burden on endoscopy services may be limited by current age-based recommendations. Restricting follow-up to those with complicated AD would reduce the number of patients requiring endoluminal investigation by 70%.

Colonoscope "Looping" During Ileo-Colonoscopy in Children is Significantly Different to that Observed in Adult Practice

OBJECTIVES

Ileo-colonoscopy (IC) can be technically challenging because of unpredictable colonoscope loop formation. Aims of this study were to assess the risk of loop formation and to attempt to understand which factors were likely to predispose to which subtype of loop.

METHODS

Prospective study conducted on children referred for an IC at Sheffield Children's Hospital. Presence and type of loop was objectively assessed using the magnetic endoscope imaging tool.

RESULTS

Three hundred procedures were prospectively evaluated. Only 9% of paediatric ICs were loop-free. Alpha loops were the most common loop in children older than 5, whereas reverse alpha loops and a wider variety of complex and repetitive loops were observed in younger patients. Once a specific type of loop has formed, the risk of re-looping in a different way or in a different position of the colon is reduced. Left lateral starting position was found to increase the risk of reverse alpha loops and re-looping. Challenging loops, such as reverse alpha, were more frequent in males. Higher body mass index (BMI) was associated with an increased risk of alpha and deep transverse loops formation, while lower BMI with a higher incidence of reverse alpha and N loop. Loop formation did not prevent 100% ileal intubation.

CONCLUSIONS

This study represents the first attempt to describe loop formation according to patient characteristics in a large paediatric series. Further studies are needed in order to establish if these findings could be helpful in simplifying the execution of IC procedures in children and facilitate the learning curve during endoscopy training programs.

TAX-Corpus: Taxonomy based Annotations for Colonoscopy Evaluation

Colonoscopy plays a critical role in screening of colorectal carcinomas (CC). Unfortunately, the data related to this procedure are stored in disparate documents, colonoscopy, pathology, and radiology reports respectively. The lack of integrated standardized documentation is impeding accurate reporting of quality metrics and clinical and translational research. Natural language processing (NLP) has been used as an alternative to manual data abstraction. Performance of Machine Learning (ML) based NLP solutions is heavily dependent on the accuracy of annotated corpora. Availability of large volume annotated corpora is limited due to data privacy laws and the cost and effort required. In addition, the manual annotation process is error-prone, making the lack of quality annotated corpora the largest bottleneck in deploying ML solutions. The objective of this study is to identify clinical entities critical to colonoscopy quality, and build a high-quality annotated corpus using domain specific taxonomies following standardized annotation guidelines. The annotated corpus can be used to train ML models for a variety of downstream tasks.

Endorobots for Colonoscopy: Design Challenges and Available Technologies

Colorectal cancer (CRC) is the second most common cause of cancer death worldwide, after lung cancer (Sung et al., 2021). Early stage detection is key to increase the survival rate. Colonoscopy remains to be the gold standard procedure due to its dual capability to optically inspect the entire colonic mucosa and to perform interventional procedures at the same time. However, this causes pain and discomfort, whereby it requires sedation or anaesthesia of the patient. It is a difficult procedure to perform that can cause damage to the colonic wall in some cases. Development of new technologies aims to overcome the current limitations on colonoscopy by using advancements in endorobotics research. The design of these advanced medical devices is challenging because of the limited space of the lumen, the contorted shape, and the long tract of the large bowel. The force applied to the colonic wall needs to be controlled to avoid collateral effects such as injuries to the colonic mucosa and pain during the procedure. This article discusses the current challenges in the colonoscopy procedure, the available locomotion technologies for endorobots used in colonoscopy at a prototype level and the commercial products available.

Novel rigidizing overtube for colonoscope stabilization and loop prevention (with video)

BACKGROUND AND AIMS

Loop formation can impede endoscope advancement, destabilize the tip, and cause pain. Strategies to mitigate looping include torque-based reduction maneuvers, variable stiffness shafts, and abdominal splinting. In some cases, these strategies are insufficient, and there is need for novel instruments. Loop formation is of particular concern in colonoscopy, but it can also impact performance of other endoscopic procedures such as enteroscopy and altered-anatomy ERCP. In this case series we demonstrate the utility of a novel rigidizing overtube (Pathfinder; Neptune Medical, Burlingame, Calif, USA) in colonoscopy and other endoscopic procedures where loop management is critical.

METHODS

We describe our initial experience with the Pathfinder overtube in 29 patients. The overtube is 85 cm long and can accommodate a pediatric colonoscope. In its native state, the overtube is extremely flexible. Once the overtube is advanced to the desired location, application of a vacuum to the device causes the device to become 15 times stiffer. The endoscope can then be advanced through the overtube without loop formation in the region that the overtube traverses.

RESULTS

The overtube was used in 29 patients to assist with difficult procedures. Patients were predominantly men (n = 18; 62.1%), with a median age of 66 years (interquartile range, 57-72). One patient received an upper endoscopy (3.4%), 24 received colonoscopy (82.8%), and 4 received enteroscopy (13.8%). The overtube was used in 12 procedures for incomplete colonoscopy (41.4%), 6 for depth (20.7%), and 11 for stability (37.9%). Colonoscopy was performed in the setting of screening (n = 3), surveillance given polyp history (n = 7), referrals for polyp removal (n = 10), workup of iron deficiency anemia (n = 2), and incomplete colonoscopy (n = 1). The lower endoscopy cases had a median cecal intubation time of 5 minutes (interquartile range, 4.25-7). Enteroscopy was performed in 4 patients: In one patient the distal 60 cm of the ileum was examined with a pediatric colonoscope to exclude ileitis, in another the overtube was used to stabilize a 6-mm endoscope to traverse a tight Crohn's ileocolonic stricture, in a third patient altered-anatomy ERCP was performed using an enteroscope through the overtube to reach a hepaticojejunostomy, and in the final patient upper enteroscopy was performed and the mid-jejunum was reached. We present 4 cases that demonstrate the use of the overtube. There were no adverse events.

CONCLUSIONS

Initial experience with a novel rigidizing overtube suggests that this tool can be useful in colonoscopy and other endoscopic procedures affected by looping.

Performance of radiographic imaging after incomplete colonoscopy for nonmalignant causes in clinical practice

BACKGROUND AND AIMS

CT colonography (CTC) or barium enema are commonly ordered to complete colorectal imaging after an incomplete colonoscopy. We evaluated the sensitivity of radiographic studies performed for this purpose in clinical practice outside clinical trials.

METHODS

Adult patients referred to an expert endoscopist for incomplete colonoscopy because of a redundant colon or a difficult sigmoid and who underwent previous radiographic imaging between July 2001 and July 2019 were identified. None of the patients had a malignant obstruction as the cause of incomplete colonoscopy. Data on polyp size, location, and pathology were obtained from colonoscopy and radiology reports. Polyps identified on imaging and colonoscopy were matched based on polyp size and location.

RESULTS

Among 769 patients referred for incomplete colonoscopy, we identified 65 with a radiographic examination performed within 36 months of colonoscopy at our center. Per-patient sensitivity for CTC was suboptimal (70%) and was very low for barium enema (26.7%). Per-polyp sensitivity for both CTC and barium enema was poor (23.8% and 7.6%). Quality of the examination did not seem to affect procedure sensitivity.

CONCLUSIONS

Radiographic imaging after incomplete colonoscopy for reasons other than malignant obstruction had poor sensitivity for polyps. Patients with incomplete colonoscopies should be considered for repeat colonoscopy by an expert.

Efficacy and Tolerability of Prucalopride in Bowel Preparation for Colonoscopy: A Systematic Review and Meta-Analysis

INTRODUCTION

Adequate bowel preparation is a vital determinant for the success of colonoscopy. However, individuals who undergo bowel preparation for colonoscopy can experience major discomfort. To solve this problem, adding prucalopride to the prepared solution may reduce intake volume, decreasing discomfort and side effects. We performed meta-analyses and systematic review of available randomized controlled trials.

METHODS

Meta-analyses were conducted to evaluate the overall relative risk and 95% confidence intervals in the combined studies for the assessment of primary outcome, which is the efficacy of bowel preparation with the addition of prucalopride.

RESULTS

Four randomized controlled trials involving 581 patients were included. When data were pooled for all patients in two non-inferiority studies, no significant difference in the quality of bowel preparation was observed between patients receiving prucalopride plus bowel preparation solution at a lower volume and those receiving the existing solution (relative risk: 0.94; 95% confidence interval: 0.86-1.03). The effects of prucalopride on acceptability, adverse events, adenoma detection rate, and polyp detection rate did not significantly differ from those of traditional solutions.

CONCLUSIONS

The combination of prucalopride and bowel preparation solution at a lower volume has similar effects on bowel preparation, and its use did not increase the occurrence of adverse effects.

The Yield and Safety of Screening Colonoscopy in Patients Evaluated for Liver Transplantation

Colorectal cancer (CRC) screening with colonoscopy is commonly used in patients who are candidates for liver transplantation. We initiated this study to define the risk-benefit ratio of performing screening colonoscopy in this population. A retrospective observational study of all consecutive patients undergoing colonoscopy during pre-liver transplantation screening between 2004 and 2017 was conducted. Endoscopic and pathological findings and clinical events potentially related to the colonoscopy in the 30 days after the procedure were registered and compared with a 30-day inpatient control time frame. A total of 858 colonoscopies were performed in 808 patients (65% male; median age, 55 years [interquartile range (IQR), 47-62]; median model for end-stage liver disease (MELD) score, 15 [IQR, 11-18]). CRC was found in 2 patients (0.2%), and advanced adenomas were found in 44 patients (5.4%). The only independent risk factor for an advanced neoplasm was age (odds ratio, 1.072 per year; 95% confidence interval, 1.031-1.115; P < 0.001). During the 30-day postprocedure period, 178 clinical events occurred in 128 patients compared with 101 clinical events in 72 patients in the control time frames (P < 0.001). After colonoscopy, there was a significantly increased risk for renal failure (P = 0.001) and gastrointestinal (GI) bleeding (P = 0.023). Presence of ascites and MELD score were identified as independent risk factors for acute renal failure and GI bleeding. During the study observation period, 53.5% of the screened population actually underwent liver transplantation. Conclusion: CRC screening in pre-liver transplantation patients is associated with a relatively low prevalence of CRC and an increased risk of postcolonoscopy complications such as acute renal failure and GI bleeding, especially in patients with advanced liver disease. Because the risk-benefit ratio of standard performance of a screening colonoscopy in this population appears questionable, alternative screening strategies should be considered.

A randomized controlled trial comparing the efficacy of 1-L polyethylene glycol solution with ascorbic acid plus prucalopride versus 2-L polyethylene glycol solution with ascorbic acid for bowel preparation

OBJECTIVES

Bowel cleansing is a major patient complaint during colonoscopy. Adding laxatives to the bowel preparation is effective in replacing a portion of bowel preparation solution and reducing its volume. Prucalopride is a serotonin receptor agonist that stimulates gastrointestinal motility and provides propulsive force for defecation. This study aimed to compare 1 L polyethylene glycol (PEG) with ascorbic acid (Asc) plus 2 mg prucalopride (1LP/AP) and 2 L PEG with Asc (2LP/A) for colonoscopy preparation with respect to bowel-cleansing quality and side effects.

METHODS

A single-center, randomized, prospective study was conducted with 260 outpatients administered either 1LP/AP or 2LP/A. The primary endpoint was bowel preparation quality, which was evaluated using the Boston Bowel Preparation Scale and Aronchick Bowel Preparation Scale, and the secondary endpoints were patient tolerability and acceptability, assessed by a questionnaire-based survey.

RESULTS

The adequate bowel preparation rates were 88.5% and 83.1% in the 2LP/A and 1LP/AP groups, respectively, and the efficacy of 1LP/AP was equivalent to the control regimen (p=.216). Other colonoscopic variables including adenoma detection rate were similar in both groups. Patient tolerability and acceptability were not significantly different, but patients in the 1LP/AP group were more willing to repeat the same regimen (p=.039).

CONCLUSIONS

Bowel preparation quality with 1LP/AP was equivalent to that with 2LP/A, which did not increase the occurrence of side effects, but it reduced the volume of the solution ingested, and increased patient satisfaction.

Use of diphenhydramine as an adjunctive sedative for colonoscopy in patients on chronic opioid therapy: a randomized controlled trial

BACKGROUND AND AIMS

Chronic opioid use increases tolerance to sedatives. Diphenhydramine is recommended for difficult-to-sedate patients during endoscopic procedures. We hypothesized that the addition of diphenhydramine to midazolam and fentanyl would improve objective and subjective measures of procedural sedation.

METHODS

This randomized, double-blind, placebo-controlled trial included patients on chronic opioids undergoing colonoscopy. Patients were randomized to receive 50 mg of diphenhydramine intravenously (n = 61) or placebo (n = 58), in addition to fentanyl and midazolam. Baseline characteristics, amount of fentanyl and midazolam, procedure times, and adverse events were recorded. Quality of sedation was assessed by the physician and nurse. Patients rated pain and amnesia on a 10-point scale.

RESULTS

There was no difference in amounts of fentanyl (125.4 ± 56.2 μg vs 126.9 ± 53.5 μg, P = .88) and midazolam (4.9 ± 2.1 mg vs 5 ± 1.9 mg, P = .79) used. The mean sedation scores from the physician (6.2 ± 1.1 vs 5.3 ± 1.2, P =.0002) and nurses (5.6 ± 1.5 vs 5.1 ± 1.4, P =.04) were statistically significant in favor of the diphenhydramine arm. Patient scores for pain (2.05 ± 2.17 vs 3.09 ± 3.95, P =.047) and amnesia (7.8 ± 3.4 vs 6.5 ± 3.8, P =.047) favored the group that received diphenhydramine. Qualitative assessment showed no significant difference between the groups. There was no difference in induction time (P = .86), procedure duration (P = .98), or recovery time (P = .16). Hypotensive episodes were more common in the placebo group (P = .027).

CONCLUSIONS

In patients on chronic opioid therapy, administration of diphenhydramine does not allow for lower doses of procedural sedatives but improves quality of sedation without increasing the number of adverse events. (Clinical trial registration number: NCT T01967433.).

Colonoscopy learning curves for colorectal surgery fellow trainees: experiences with the 15-year colonoscopy training program

Purpose

This study aimed to analyze the learning curves for colorectal surgery fellows in a colonoscopy training program.

Methods

Between May 2003 and February 2017, 60 surgical fellows joined our 1-year colonoscopy training program as trainees and performed 43,784 cases of colonoscopy. All trainees recorded their colonoscopy experiences prospectively into the database. After excluding 6 trainees, who had experience with performing more than 50 colonoscopies before participating in our training program or who discontinued our training program with experience performing less than 300 colonoscopies, this study included 54 trainees who had performed 39,539 colonoscopy cases. We analyzed the cecal intubation rate (CIR) and cecal intubation time (CIT) using the cumulative sum (Cusum) technique and moving average method to assess the technical colonoscopy competence.

Results

Overall, the CIR by the trainees was 80.7%. The median number of cases of colonoscopy performed during the training period for each trainee was 696 (range, 322–1,669). The trainees were able to achieve a 90% CIR with 412 and 493 procedures when analyzed using the moving average and the Cusum, respectively. Using the moving average method, CIRs after 150, 300, and 400 procedures were 67.0%, 84.1%, and 89.2%, respectively. The CIT of trainees continuously decreased until 400 successful cases. Median CITs were 9.4, 8.3, and 7.4 minutes at 150, 300, and 400 successful cases, respectively.

Conclusion

We found that more than 400 cases of experience were needed for technical competence in colonoscopy. Continuous teaching and monitoring is required until trainees become sufficiently competent.

A symptom-based model to predict colorectal cancer in low-resource countries: Results from a prospective study of patients at high risk for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) rates in low-resource countries, which typically lack CRC screening programs, are rising. This study determined whether a risk model for patients with rectal bleeding could identify patients with curable CRC.

METHODS

This prospective, cross-sectional study evaluated a model constructed from data from 1 hospital and validated at 2 other hospitals. The primary endpoint was the ability of the model to predict CRC, as diagnosed by colonoscopy, from clinical characteristics. The secondary endpoint was to determine the percentage of patients who had CRC.

RESULTS

Consecutive patients who were 45 years old or older and had self-reported rectal bleeding for more than 1 week were evaluated. From January 2014 to July 2016, 362 patients answered a questionnaire and underwent colonoscopy. In the validation cohort, 56% of patients with rectal bleeding, weight loss, and changes in bowel habits had CRC, whereas 2% of patients with bleeding alone did. Overall, 18.2% of the patients had CRC, and 8.6% had adenomas. The proportion of CRC patients with potentially curable stage II or III disease was 74%, whereas the historical rate was 36%. The combination of rectal bleeding with both symptoms significantly predicted CRC in the validation set (odds ratio, 12.8; 95% confidence interval, 4.6-35.4; P < .001).

CONCLUSIONS

In low-resource settings, patients with rectal bleeding, weight loss, and changes in bowel habits should be classified as high risk for CRC. Patients with a high risk score should be prioritized for colonoscopy to increase the number of patients diagnosed with potentially curable CRC. Cancer 2018;124:2766-2773. © 2018 American Cancer Society.

Using the plan-do-study-act approach to improve inpatient colonoscopy preparation

Poor inpatient colonoscopy preparations can provide multiple challenges to healthcare providers and patients alike. Poor preparations can make the colonoscopy difficult to perform, and can require the procedure to be repeated. This can in turn lead to greater costs, longer length of stays, less patient satisfaction and worse outcomes. The aim of this quality improvement project was to decrease the rate of poor inpatient colonoscopy preparations using the plan-do-study-act approach. Inpatient colonoscopies at our institution from a 3-month span (November 2016 to January 2017) were evaluated, and found to have a 19% rate of poor preparations. A multiphase intervention programme was then conducted to improve the quality of these preparations. This intervention programme was threefold, and involved (1) direct education to physicians and nursing staff on the preparation process and its importance; (2) the implementation of an electronic order set within our electronic medical record (EMR) to standardise and simplify the process of ordering colonoscopy preparations; and (3) patient education in the form of a handout explaining the steps and importance of a good preparation. Through these interventions, we were able to bring down our rate of poor preparations over a 3-month average from 19% to 4%. Specifically, the implementation of an electronic order set within our EMR resulted in the greatest impact. Our interventions can be replicated at other institutions in order to decrease the rate of poor preparations, and thus result in better outcomes for patients, providers and healthcare facilities.

Clinical Practice Guidelines for the Use of Video Capsule Endoscopy

BACKGROUND & AIMS

Video capsule endoscopy (CE) provides a noninvasive option to assess the small intestine, but its use with respect to endoscopic procedures and cross-sectional imaging varies widely. The aim of this consensus was to provide guidance on the appropriate use of CE in clinical practice.

METHODS

A systematic literature search identified studies on the use of CE in patients with Crohn's disease, celiac disease, gastrointestinal bleeding, and anemia. The quality of evidence and strength of recommendations were rated using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

The consensus includes 21 statements focused on the use of small-bowel CE and colon capsule endoscopy. CE was recommended for patients with suspected, known, or relapsed Crohn's disease when ileocolonoscopy and imaging studies were negative if it was imperative to know whether active Crohn's disease was present in the small bowel. It was not recommended in patients with chronic abdominal pain or diarrhea, in whom there was no evidence of abnormal biomarkers typically associated with Crohn's disease. CE was recommended to assess patients with celiac disease who have unexplained symptoms despite appropriate treatment, but not to make the diagnosis. In patients with overt gastrointestinal bleeding, and negative findings on esophagogastroduodenoscopy and colonoscopy, CE should be performed as soon as possible. CE was recommended only in selected patients with unexplained, mild, chronic iron-deficiency anemia. CE was suggested for surveillance in patients with polyposis syndromes or other small-bowel cancers, who required small-bowel studies. Colon capsule endoscopy should not be substituted routinely for colonoscopy. Patients should be made aware of the potential risks of CE including a failed procedure, capsule retention, or a missed lesion. Finally, standardized criteria for training and reporting in CE should be defined.

CONCLUSIONS

CE generally should be considered a complementary test in patients with gastrointestinal bleeding, Crohn's disease, or celiac disease, who have had negative or inconclusive endoscopic or imaging studies.

Regional center for complex colonoscopy: yield of neoplasia in patients with prior incomplete colonoscopy

BACKGROUND AND AIMS

Incomplete colonoscopy increases the risk of incident proximal colon cancer postcolonoscopy. Incomplete colonoscopy is often followed by barium enema or CT colonography. We sought to describe the yield of completion colonoscopy in a regional center for complex colonoscopy.

METHODS

This is a retrospective cohort study of 520 consecutive patients referred to a single colonoscopist over a 14-year period for completion colonoscopy after a previous incomplete examination.

RESULTS

Colonoscopy was completed to the cecum in 506 of 520 patients (97.3%). A total of 913 conventional adenomas was removed in 277 patients (adenoma detection rate 53.3%). There were 184 adenomas ≥ 1 cm in size or with advanced pathology. There were 525 serrated-class lesions removed in 175 patients, including 54 sessile serrated polyps in 26 patients and 41 hyperplastic polyps greater than 1 cm in 26 patients. Nine colorectal cancers were found. We estimated that approximately 57% of the conventional adenomas, 58% of the sessile serrated polyps, 27% of the hyperplastic polyps, and all 9 cancers detected by the completion colonoscopy were beyond the extent of the previous examination.

CONCLUSIONS

The yield of completion colonoscopy in a cohort of patients with previous failed cecal intubation was substantial. Regional centers for complex colonoscopy can provide high rates of cecal intubation in cases of incomplete colonoscopy and high yields of lesions in these cases. The regional center for complex colonoscopy is an important medical service.

[Risk factors of pain during colonoscopic examination]

OBJECTIVE

To investigate the risk factorsthat predict pain during colonoscopy for decision of sedation or analgesia before the examination.

METHODS

A total of 283 consecutive patients undergoing colonoscopicexamination at Nanfang Hospital between July, 2016 and September, 2016were retrospectively analyzed. The clinical data and visual analogue scale after the examination were analyzed to identify the risk factors for pain during colonoscopy using univariate analysis and multivariate logistic regression. A risk stratification model for predicting pain in colonoscopy was established.

RESULTS

The completion rate of the procedure was significantly lower in patients with a visual analogue scale ≥5 (P<0.000). Univariate analysis showed that female patients, previous abdominal surgery, no previous experience with colonoscopy, complaint of abdominal pain before colonoscopy, insufficient experience of the endoscopists, patient's anticipation of high painlevelbefore examination, and a low body mass index (BMI) were all associated with the experience of pain in colonoscopy (P<0.05). Multivariate logistic regressionanalysis identified BMI index (X₁), level of experience of the endoscopist (A₁, A₂, A₃) and the patient's anticipation of painlevel (X₂) as the risk factors of pain in colonoscopy(P<0.05), and the establishedmodel with the 3 variables was: P=e^Y/(1+e^Y),Y=0.049-0.124×X₁-0.97×X₂+1.713×A₁+0.781×A₂+0.147×A₃, which showed a sensitivity of 70.3% and a specificity of 67.5%for predicting pain in colonoscopy.

CONCLUSION

The patient's anticipation of a high pain level in colonoscopy, insufficient experience of the endoscopist, and a low BMI are the independent risk factors for pain in colonoscopy, and evaluation of these factors can help in the decision-making concerning the use of sedation or analgesia before colonoscopy.

The role of single-balloon colonoscopy for patients with previous incomplete standard colonoscopy: Is it worth doing it?

BACKGROUND

The rate of cecal intubation is a well-recognized quality measure of successful colonoscopy. Infrequently, the standard colonoscopy techniques fail to achieve complete examination. The role of single-balloon overtube-assisted colonoscopy (SBC) in these situations has only been sparsely studied. This prospective single-center study aimed to investigate the technical success (rate of cecal intubation) and the diagnostic gain of SBC.

METHODS

The study recruited consecutive patients with previous incomplete standard colonoscopy who were admitted for SBC at our tertiary center in Eastern Switzerland between February 2008 and October 2014. The primary outcome was defined as successful cecal intubation. Data on patient characteristics, indication, technical details of procedure, and outcome were collected prospectively. The Olympus enteroscope SIF-Q180 was used.

RESULTS

The study included 100 consecutive patients (median age 70 years; range 38-87 years; 54 % female) who were examined using a single-balloon overtube-assisted technique. The cecal intubation rate was 98 % (98/100). The median time of total procedure was 54 min (range 15-119 min); the median time to reach the cecal pole was 27.5 min (range 4-92 min). Passage of the sigmoid colon was not possible in two cases with a fixed, angulated sigmoid colon. The diagnostic gain was 21 % regarding adenomatous polyps in the right colon. The complication rate was 2 % (2/100, minor) without need for surgery.

CONCLUSIONS

This prospective patient cohort study shows that single-balloon colonoscopy is a safe and effective procedure to achieve a complete endoscopic examination in patients with a previous failed standard colonoscopy. A significant diagnostic and therapeutic gain in the right colon justifies additional procedure time.

Comparison of polyethylene glycol vs sodium picosulphate vs sodium biphosphonate by efficacy in bowel cleansing and patients' tolerability: a randomised trial

INTRODUCTION

Adequate bowel preparation is necessary for a complete colonoscopy. Polyethylene glycol-electrolyte oral solution (PEG-EOS), sodium picosulphate (SS) and sodium biphosphonate (SP) are the three most commonly used purgative agents. We aimed to determine their efficacy and tolerability compared to each other in a randomised study.

METHODS

313 patients were randomly assigned to receive either PEG-EOS, SS or SP. Patients completed a tolerability score pre-colonoscopy. A cleanliness score was used to document adequacy of bowel preparation. A separate group of patients completed taste scores for the three cathartic agents before and after addition of flavour.

RESULTS

PEG-EOS was the worst-tolerated regimen but achieved the highest rates of right colonic cleansing and the lowest rate of incomplete colonoscopies. There were no statistical differences in the rates of rectosigmoid and mid-gut cleansing among the three agents. SS was by far the preferred purgative in the taste assessment study. Addition of flavour increased significantly taste scores for PEG-EOS.

CONCLUSION

For adequate bowel cleansing PEG-EOS is the most effective but is the least tolerated and least preferred among patients. Addition of flavour increases significantly patients' acceptance of PEG-EOS.

An analysis of the learning curve to achieve competency at colonoscopy using the JETS database

OBJECTIVE

The number of colonoscopies required to reach competency is not well established. The primary aim of this study was to determine the number of colonoscopies trainees need to perform to attain competency, defined by a caecal intubation rate (CIR) ≥90%. As competency depends on completion, we also investigated trainee factors that were associated with colonoscopy completion.

DESIGN

The Joint Advisory Group on GI Endoscopy in the UK has developed a trainee e-portfolio from which colonoscopy data were retrieved. Inclusion criteria were all trainees who had performed a total of ≥20 colonoscopies and had performed ≤50 colonoscopies prior to submission of data to the e-portfolio. The primary outcome measure was colonoscopy completion. The number of colonoscopies required to achieve CIR ≥90% was calculated by the moving average method and learning curve cumulative summation (LC-Cusum) analysis. To determine factors which determine colonoscopy completion, a mixed effect logistic regression model was developed which allowed for nesting of patients within trainees and nesting of patients within hospitals, with various patient, trainee and training factors entered as fixed effects.

RESULTS

297 trainees undertook 36 730 colonoscopies. By moving average analysis, the cohort of trainees reached a CIR of 90% at 233 procedures. By LC-Cusum analysis, 41% of trainees were competent after 200 procedures. Of the trainee factors, the number of colonoscopies, intensity of training and previous flexible sigmoidoscopy experience were significant factors associated with colonoscopy completion.

CONCLUSIONS

This is the largest study to date investigating the number of procedures required to achieve competency in colonoscopy. The current training certification benchmark in the UK of 200 procedures does not appear to be an inappropriate minimum requirement. The LC-Cusum chart provides real time feedback on individual learning curves for trainees. The association of training intensity and flexible sigmoidoscopy experience with colonoscopy completion could be exploited in training programmes.

High success rate of repeat colonoscopy with standard endoscopes in patients referred for prior incomplete colonoscopy

BACKGROUND

In patients with incomplete colonoscopy, cecal intubation is sometimes unsuccessful due to a redundant or tortuous colon. Repeat colonoscopy may be successful with the use of alternate endoscopes or careful attention to technique but limited outcomes data is available. The aim of this study was to describe the technique, success rate and outcomes of consecutive patients referred for previous incomplete colonoscopy.

METHODS

We conducted a retrospective chart review of incomplete colonoscopy procedures in patients age 18-90 at an academic teaching hospital referred to an endoscopist specializing in difficult colonoscopy.

RESULTS

Cecal intubation was successful in 96 of 100 repeat colonoscopies and 83 procedures were completed with a standard endoscope (adult, pediatric, or gastroscope). The adenoma detection rate was 28% for successful repeat colonoscopies; a majority of these patients had no adenomas identified on incomplete exam. In 69.4% of cases, an endoscope was used to successfully complete colonoscopy that was not used in the incomplete colonoscopy. The median insertion time was significantly less for the complete colonoscopy (10.6 min) compared to the incomplete colonoscopy (18.8 min, P = 0.004).

CONCLUSIONS

Repeat colonoscopy has a high success rate and identified a significant number of new adenomas. Use of all available endoscopes should be considered prior to procedure termination in patients with a tortuous colon. Repeat colonoscopy can often be accomplished using a standard endoscope and is not attributed to increased endoscope insertion time.

Colon capsule endoscopy is feasible to perform after incomplete colonoscopy and guides further workup in clinical practice

BACKGROUND

Colon capsule endoscopy (CCE) could be an option to examine the colon after incomplete colonoscopy.

OBJECTIVE

To investigate the extent that CCE complements incomplete colonoscopy and guides further workup.

DESIGN

Prospective, follow-up study.

SETTING

Three tertiary-care centers.

PATIENTS

Consecutive outpatients after colonoscopy failure; 1-year study period.

INTERVENTION

Patients underwent CCE either immediately after colonoscopy or were rescheduled. Further investigations were guided by the results of CCE. Patients were followed as long as 2 years.

RESULTS

We studied 75 outpatients; 39 had a screening colonoscopy. One third of the patients underwent CCE immediately after colonoscopy. Overall, CCE reached or went beyond the colon segment at which colonoscopy stopped in 68 patients (91%). CCE technically complemented difficult colonoscopy independently of whether same-day CCE was performed (24 [96%]) or was not performed (44 [88%]). CCE detected additional significant findings in 36% of the same-day CCE cases and in 48% of the rescheduled ones. Two patients in the same-day group and 13 in the rescheduled CCE group underwent further colon examination that revealed additional significant findings in 3 of them. Ten percent of the patients reported mild adverse events (AE). If needed, 63 participants (84%) were willing to repeat CCE. Follow-up has not identified symptomatic missed colon cancers.

LIMITATIONS

Selected patient population, first-generation colon capsule, old preparation scheme.

CONCLUSION

CCE performed immediately or at a scheduled date after colonoscopy failure is feasible and safe. CCE after incomplete colonoscopy appears to yield significant findings, guide further workup, and has high patient acceptance.

Patient-controlled analgesia with inhaled methoxyflurane versus conventional endoscopist-provided sedation for colonoscopy: a randomized multicenter trial

OBJECTIVE

Inhaled methoxyflurane (Penthrox, Medical Device International, Melbourne, Australia) has been used extensively in Australasia (Australia and New Zealand) to manage trauma-related pain. The aim is to evaluate the efficacy, safety, and outcome of Penthrox for colonoscopy.

DESIGN

Prospective randomized study.

SETTING

Three tertiary endoscopic centers.

PATIENTS

Two hundred fifty-one patients were randomized to receive either Penthrox (n = 125, 70 men, 51.4 ± 1.1 years old) or intravenous midazolam and fentanyl (M&F; n = 126, 72 men, 54.9 ± 1.1 years old) during colonoscopy.

MAIN OUTCOME MEASUREMENT

Discomfort (visual analogue scale [VAS] pain score), anxiety (State-Trait Anxiety Inventory Form Y [STAI-Y] anxiety score), colonoscopy performance, adverse events, and recovery time.

RESULTS

Precolonoscopy VAS pain and STAI-Y scores were comparable between the 2 groups. There were no differences between groups in (1) pain VAS or STAI Y-1 anxiety scores during or immediately after colonoscopy, (2) procedural success rate (Penthrox: 121/125 vs M&F: 124/126), (3) hypotension during colonoscopy (7/125 vs 8/126), (4) tachycardia (5/125 vs 3/126), (5) cecal arrival time (8 ± 1 vs 8 ± 1 minutes), or (6) polyp detection rate (30/125 vs 43/126). Additional intravenous sedation was required in 10 patients (8%) who received Penthrox. Patients receiving Penthrox alone had no desaturation (oxygen saturation [SaO(2)] < 90%) events (0/115 vs 5/126; P = .03), awoke quicker (3 ± 0 vs 19 ± 1 minutes; P < .001) and were ready for discharge earlier (37 ± 1 vs 66 ± 2 minutes; P < .001) than those receiving intravenous M&F.

LIMITATIONS

Inhaled Penthrox is not yet available in the United States and Europe.

CONCLUSIONS

Patient-controlled analgesia with inhaled Penthrox is feasible and as effective as conventional sedation for colonoscopy with shorter recovery time, is not associated with respiratory depression, and does not influence the procedural success and polyp detection.

Colonoscopy practice in lagos, Nigeria: a report of an audit

Background. Colonoscopy effectiveness depends on the quality of the examination. Community-based report of quality of colonoscopy practice in a developing country will help in determining standard and also serve as a stimulus for improvement in service. Aim. To review the quality of colonoscopy practice and document pattern of colonic disease including polyp detection rate in Lagos, Nigeria. Method. A protocol that captured the patients' demographics, indication, and some quality indices of colonoscopy was developed and sent to all the identified colonoscopy units in Lagos to complete for all procedures performed between January 2011 and June 2012. All data were collated and analyzed. The quality indices studied were compared with guideline standard. Results. Twelve colonoscopy centers were identified but only nine centers responded. The gastroenterologist/endoscopists were physicians (3) and surgeons (5). Six hundred and seven colonoscopy procedures were performed during this period (M : F = 333 : 179) while the sex was not disclosed in 95 subjects. The examination indications were lower GI bleeding (24.2%), altered bowel habits (9.2%), lower abdominal pain (9.1%), screening for CRC (4.3%) and unspecified (46.8%). Conscious sedation was generally used while bowel preparation (good in 81.4%) was done with low residue diet and stimulant laxatives. Caecal intubation rate was 81.2%. Common endoscopic findings were haemorrhoids (43.2%), polyps/masses (13.4%), diverticulosis (11.1%), and no abnormality (23.4%). Polyp was detected in 6.8% of cases. Conclusion. Colonoscopy utilization is low, and the quality of practice is suboptimal; although limited resources could partly explain this, however it is not clear if the low rate of polyp detection is due to missed lesions or low population incidence.