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

Efficacy and tolerability of 1 L polyethylene glycol plus ascorbic acid with senna versus 2 L polyethylene glycol plus ascorbic acid for colonoscopic bowel preparation: Prospective, randomized, investigator-blinded trial

OBJECTIVES

Low-volume polyethylene glycol plus ascorbic acid (PEG-Asc) reduces the dosage of colonoscopic bowel preparation (BP) solution, but is still poorly tolerated. Adding laxatives to the BP solution reduces the volume of fluid required, without affecting quality. This study aimed to compare 1 L PEG-Asc plus 24 mg senna (1L-PEG/AS) and conventional 2 L PEG-Asc (2L-PEG/A) regimens on BP quality and patient tolerability.

METHODS

A single-center, randomized, investigator-blinded, noninferiority trial was performed between June and August 2022. Outpatients scheduled for colonoscopy were randomized (1:1) to the 1L-PEG/AS or 2L-PEG/A group. The Boston Bowel Preparation Scale (BBPS) was used to evaluate BP quality. Adverse events and tolerability were surveyed using questionnaires.

RESULTS

Overall, 344 patients received 1L-PEG/AS or 2L-PEG/A regimens. The baseline characteristics and adverse events of the two groups were comparable. The 1L-PEG/AS group showed noninferior adequate BP rates compared with the 2L-PEG/A group (88% vs. 89%, P = 1.00); overall BBPS was 7.1 ± 1.5 and 7.2 ± 1.5, respectively (P = 0.39). Higher willingness to repeat the BP was observed in the 1L-PEG/AS group (85% vs. 62%, P < 0.01).

CONCLUSIONS

The 1L-PEG/AS regimen was comparable to the 2L-PEG/A regimen in terms of BP adequacy, requiring lower BP solution volumes, with better patient tolerance. Thus, it may be a suitable alternative to the conventional BP solution for colonoscopy. The Japan Registry of Clinical Trials (jRCT1051220043).

Diagnostic Yields and Clinical Impacts of Capsule Endoscopy

Observing the entire small bowel is difficult due to the presence of complex loops and a long length. Capsule endoscopy (CE) provides a noninvasive and patient-friendly method for visualizing the small bowel and colon. Small bowel capsule endoscopy (SBCE) has a critical role in the diagnosis of small bowel disorders through the direct observation of the entire small bowel mucosa and is becoming the primary diagnostic tool for small bowel diseases. Recently, colon capsule endoscopy (CCE) was also considered safe and feasible for obtaining sufficient colonic images in patients with incomplete colonoscopy, in the absence of bowel obstruction. This review article assesses the current status of CE in terms of the diagnostic yield and the clinical impact of SBCE in patients with obscure gastrointestinal bleeding, who have known or suspected Crohn's disease, small bowel tumor and inherited polyposis syndrome, celiac disease, and those who have undergone CCE.

Congenital positional anomaly of descending colon and sigmoid colon: Its embryological basis and clinical implications

The rotation of the midgut is essential for normal placement of intestines in the abdominal cavity. The process of midgut rotation and simultaneous retraction of the herniated intestinal loops pushes the hind gut to the left side of the abdominal cavity. So the descending colon and the sigmoid colon occupy the left side of the abdominal cavity. In this report, we document a male cadaver that revealed right-sided sigmoid colon. On further dissection, the descending colon was found lying in the midline with a small peritoneal fold stretching from the right side of sigmoid colon to ileocecal junction. There was also variation in the inferior mesenteric artery supplying the displaced descending colon and sigmoid colon. The possible embryological and molecular basis of this variation has been discussed. The anatomical knowledge of this variation is essential for interventional and diagnostic colonoscopy procedures and colonic surgeries.

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.

When Experts Fail: Use of a Short Turning Radius Colonoscope Facilitates Successful Completion of Colonoscopy in Patients with Bowel Fixity

BACKGROUND

Rates of incomplete colonoscopy in non-expert settings range up to 13%. Expert colonoscopists can complete ~ 95% colonoscopies when other endoscopists fail; however, a small number remain incomplete even in expert hands, typically due to bowel fixity.

AIMS

Pentax Retroview™ (EC-3490TLi) is a new slim colonoscope with a short turning radius (STR) and greater tip deflection (210°), which allows easy maneuverability across sharply angulated/fixed colonic bends. We evaluated the utility of this colonoscope for completing colonoscopies that fail even in the hands of expert colonoscopists.

METHODS

Retrospective chart review was performed, and main outcomes measured included cecal intubation rate, lesions detected, dosage of sedation used, and complications.

RESULTS

Using the STR colonoscope, complete colonoscopy to the cecum was possible in 34/37 patients (91.9%). No loss of lumen/blind advancement was necessary in any of the procedures. No adverse events occurred. Among the completed colonoscopies, 6/34 (17.6%) patients had adenomas, all proximal to the site of prior failure, including one advanced adenoma. All failures (n = 3, 8.1%) had a history of cancer surgeries, with peritoneal carcinomatosis/extensively fixed/frozen bowel (two patients) and an additional diverticular stricture with colo-vesical fistula (one patient).

CONCLUSION

STR colonoscope facilitates completion of a high proportion (91.9%) of colonoscopies that previously failed in expert hands. Its STR allows easy maneuverability across segments of sharp angulation with bowel fixity without need for blind advancement. The use of this colonoscope led to the detection of adenomas in 17.6% of patients, all proximal to the site of prior failed colonoscopy.

Emerging next-generation robotic colonoscopy systems towards painless colonoscopy

Advances in the field of robotics have allowed modern technology to be integrated into medicine and that can minimize patients suffering from the side effects that are inherent to procedures for improving their quality of life. Conventional devices that are used for colonoscopies are rigid and require a high level of expertise from endoscopists to perform the procedure. Advances in robot-assisted colonoscopic systems now produce softer, more slender, automated designs that no longer require the operator to use forceful pushing to advance the colonoscope inside the colon, reducing risks to the patient of perforation and pain. It is challenging to reprocess these scopes for reuse as the materials used can be damaged during decontamination, leading to the possible risks of cross-infection by pathogenic microorganisms when reused by patients. An ideal solution is to eliminate these contamination risks to patients by adopting sterile, single-use scopes straight from the manufacturer's package to the patient. With this idea in mind, emerging developments that push the boundaries in this area will benefit patients and encourage the public to participate in and adhere better to colonoscopy screening to reduce the development of colorectal cancer. Thus, in light of these concerns and challenges, to encourage patients undergoing colorectal screening to comply with colonoscopy procedures that they are less invasive, changes in the design and materials are necessary. One of the more promising technological advances in this area is the advent of robotic colonoscopy.

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.

High Efficacy of Repeating Colonoscopy by an Advanced Endoscopist after an Incomplete Colonoscopy

Background and Aims

This study aims to evaluate the role of an advanced endoscopist to study the entire colon after an incomplete colonoscopy.

Methods

All patients with an elective incomplete colonoscopy performed under deep sedation in our department between January 2010 and October 2016 were included. Patients with a colonic stenosis, an inadequate bowel preparation, or a colonoscopy performed without deep sedation were excluded. Included patients were followed up to evaluate if and what type of subsequent examinations (colonoscopy by an advanced endoscopist, single-balloon enteroscopy [SBE], and/or CT colonography) was performed to complete the study of the entire colon. Lesions found during these subsequent examinations were also recorded.

Results

Ninety-three patients had an incomplete colonoscopy, with no diagnosis of colorectal cancer (CRC) and a high-risk polyp rate of 5.4% (n = 5). Seventy-seven patients with incomplete colonoscopies underwent subsequent examinations, namely CT colonography in 45.5% (n = 35), colonoscopy by an advanced endoscopist in 53.2% (n = 41), and SBE in 13% (n = 10). In the 49 patients who performed either colonoscopy (n = 39) or SBE (n = 10) by an advanced endoscopist, the cecal intubation rate was 100%, and high-risk polyps were found in 26.5% (n = 13) and CRC in 4.1%. CT colonography revealed findings consistent with polyps and CRC in 22.9% (n = 8) and 2.9% (n = 1) of the cases, respectively. Colonoscopy was further repeated in 6 patients with suspected polyps in CT colonography, confirming the initial diagnosis in 5 patients.

Conclusions

Colonoscopy by an advanced endoscopist achieved cecal intubation in all patients, representing a good choice after an incomplete colonoscopy.

Double-Balloon Endoscopy after Incomplete Colonoscopy and Its Comparison with Computed Tomography Colonography

BACKGROUND/AIMS

Because of the national screening program for colorectal carcinoma in The Netherlands, the number of colonoscopies has increased. In case of incomplete colonoscopy, computed tomography colonography (CTC) and double-balloon colonoscopy (DBc) are alternative options. This study evaluated cecal intubation rate and pathology detection rate in the previously unexplored part of the colon, complication rate of DBc, and CTC results after incomplete colonoscopy.

METHODS

Retrospective observational study in a tertiary referral hospital regarding DBc and CTC reports from cases with incomplete colonoscopy.

RESULTS

Sixty-three DBcs were performed after incomplete colonoscopy. Cecal intubation rate was 95%. Detection rate was 58% (5% carcinoma and 3% high-grade dysplastic adenoma). CTC preceded 54% of DBcs and 62% of CTC findings were confirmed. In 16%, a biopsy was taken, and in 60%, an intervention (mostly polypectomy) was performed. One major complication (1.5%) occurred, i.e., arterial bleeding due to polypectomy necessitating right hemicolectomy. CTC (n=213) showed a possible lesion in 35%, and could be confirmed by follow-up endoscopy or surgery in 65%.

CONCLUSIONS

DBc is effective and safe for completion of colon inspection in incomplete colonoscopy. In patients with a high likelihood of pathology, DBc is preferred over CTC.

Development and validation of an algorithm to complete colonoscopy using standard endoscopes in patients with prior incomplete colonoscopy

BACKGROUND AND STUDY AIMS

 Incomplete colonoscopy may occur as a result of colon angulation (adhesions or diverticulosis), endoscope looping, or both. Specialty endoscopes/devices have been shown to successfully complete prior incomplete colonoscopies, but may not be widely available. Radiographic or other image-based evaluations have been shown to be effective but may miss small or flat lesions, and colonoscopy is often still indicated if a large lesion is identified. The purpose of this study was to develop and validate an algorithm to determine the optimum endoscope to ensure completion of the examination in patients with prior incomplete colonoscopy.

PATIENTS AND METHODS

 This was a prospective cohort study of 175 patients with prior incomplete colonoscopy who were referred to a single endoscopist at a single academic medical center over a 3-year period from 2012 through 2015. Colonoscopy outcomes from the initial 50 patients were used to develop an algorithm to determine the optimal standard endoscope and technique to achieve cecal intubation. The algorithm was validated on the subsequent 125 patients.

RESULTS

 The overall repeat colonoscopy success rate using a standard endoscope was 94 %. The initial standard endoscope specified by the algorithm was used and completed the colonoscopy in 90 % of patients.

CONCLUSIONS

 This study identifies an effective strategy for completing colonoscopy in patients with prior incomplete examination, using widely available standard endoscopes and an algorithm based on patient characteristics and reasons for prior incomplete colonoscopy.

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.

The correlation between diverticulosis and redundant colon

BACKGROUND

Diverticulosis and redundant colon are colonic conditions for which underlying pathophysiology, management and prevention are poorly understood. Historical papers suggest an inverse relationship between these two conditions. However, no further attempt has been made to validate this relationship. This study set out to assess the correlation between diverticulosis and colonic redundancy.

METHODS

Redundant colon, diverticulosis and patient demographics were recorded during colonoscopy. Multivariate binary logistic regression was performed with redundant colon as the dependent variable and age, gender and diverticulosis as independent variables. Nagelkerke R ² and a receiver operator curve were calculated to assess goodness of fit and internally validate the multivariate model.

RESULTS

Redundant colon and diverticulosis were diagnosed in 31 and 113 patients, respectively. The probability of redundant colon was increased by female gender odds ratio (OR) 8.4 (95% CI 2.7-26, p = 0.00020) and increasing age OR 1.7 (95% CI 1.1-2.6, p = 0.017). Paradoxically, diverticulosis strongly reduced the probability of redundant colon with OR of 0.12 (95% CI 0.42-0.32, p = 0.000039). The Nagelkerke R ² for the multivariate model was 0.29 and the area under the curve at ROC analysis was 0.81 (95% CI 0.73-0.90 p-value 3.1 × 10^-8).

CONCLUSIONS

This study found an inverse correlation between redundant colon and diverticulosis, supporting the historical suggestion that the two conditions rarely occur concurrently. The underlying principle for this relationship remains to be found. However, it may contribute to the understanding of the aetiology and pathophysiology of these colonic conditions.

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.

Predictors of incomplete optical colonoscopy using computed tomographic colonography

BACKGROUND/AIMS

Optical colonoscopy (OC) is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC). We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC.

PATIENTS AND METHODS

In this case-control study, 70 cases ( with incomplete OC) and 70 controls (with complete OC) were identified. CTC images of cases and controls were independently reviewed by a single CTC radiologist. Demographic and anatomical parameters were recorded. Data was examined using descriptive linear statistics and multivariate logistic regression model.

RESULTS

On analysis, female gender (80% vs 58.6% P = 0.007), prior abdominal/pelvic surgeries (51.4% vs 14.3% P < 0.001), colonic length (187.6 ± 30.0 cm vs 163.8 ± 27.2 cm P < 0.001), and number of flexures (11.4 ± 3.1 vs 8.4 ± 2.9 P < 0.001) increased the risk for incomplete OC. No significant association was observed for increasing age (P = 0.881) and history of severe diverticulosis (P = 0.867) with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings.

CONCLUSION

Female gender, prior surgery, and increasing colonic length and tortuosity were associated with incomplete OC, whereas increasing age and history of severe diverticulosis were not. These factors may be used in the future to predict those patients who are at risk of incomplete OC.

Interval Colorectal Cancer After Colonoscopy: Exploring Explanations and Solutions

There is good evidence that colorectal cancer (CRC) screening has been successful at reducing both CRC incidence and death. Colonoscopy, utilized as either a primary screening tool or a follow-up exam when other screening tests are positive, has significantly contributed to these encouraging trends. However, it is well recognized that colonoscopy is not perfectly sensitive for the detection of neoplasia and that CRC can be diagnosed within a short interval following a colonoscopy that did not detect one. The literature surrounding these cases has rapidly expanded over the last decade. Specifically, studies aimed at understanding the frequency of these events and the likely explanations for their occurrence have been performed. This review will highlight current knowledge around the epidemiology of interval post colonoscopy CRC (PCCRC). The common explanations for these cancers including missed lesions, new lesions, and incompletely resected lesions will be reviewed and their contribution to interval PCCRC estimated. Finally, the relationship of these putative explanations to potential opportunities to prevent interval PCCRC will be explored. Current approaches to prevention largely center on consistent adherence to quality colonoscopy standards. Future approaches include advances in technology to better visualize the colon and adequately resect detected neoplasia. Finally, improvement in training as well as development of a culture of continuous quality improvement will be essential to maximize the benefits of colonoscopy in daily clinical practice.

Frequency and efficacy of additional investigations following incomplete colonoscopies: A population-based analysis

BACKGROUND

Limited data are available on the follow-up of patients with incomplete colonoscopy following positive faecal occult blood testing. Our study aimed to determine the proportion of and reasons for incomplete colonoscopies, the proportion of patients who completed colonic evaluations, the methods used and the subsequent findings.

METHODS

A total of 9483 colonoscopies performed after positive testing in a colorectal cancer screening programme setting were included. The study was prospective for index colonoscopy findings and partly retrospective for follow-up.

RESULTS

Overall 297 colonoscopies were incomplete (3.2%). A secondary colonic evaluation was deemed necessary in 245 patients, of which 126 underwent an additional examination (51.4%). Radiology was the primary method used for complete colonic evaluation, whereas a repeat colonoscopy was performed in only 6.4%; the examination was normal in 119 patients (94.4%). A mucosal high-grade neoplasia was removed in 1, and multiple (≥3) adenomas were removed in 2 patients.

CONCLUSIONS

The present screening programme with biennial faecal occult blood testing revealed a high colonoscopy completion rate, a low rate of secondary colonic evaluation, infrequent use of colonoscopy for completion, and a low detection rate of significant neoplasia.

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.