Predictors for difficult cecal insertion in colonoscopy: The impact of obesity indices

Constipation and colonoscopy

Constipation is a significant sociomedical problem, which can be caused by various reasons. In the diagnostic approach to patients with constipation, the following data are usually sufficient: History, complete physical examination (including rectal examination), and additional diagnostic tests. A colonoscopy is not a necessary diagnostic method for all patients with constipation. However, if patients have alarm symptoms/signs, that suggest an organic reason for constipation, a colonoscopy is necessary. The most important alarm symptoms/signs are age > 50 years, gastrointestinal bleeding, new-onset constipation, a palpable mass in the abdomen and rectum, weight loss, anemia, inflammatory bowel disease, and family history positive for colorectal cancer. Most endoscopists do not like to deal with patients with constipation. There are two reasons for this, namely the difficulty of endoscopy and the adequacy of preparation. Both are adversely affected by constipation. To improve the quality of colonoscopy in these patients, good examination techniques and often more extensive preparation are necessary. Good colonoscopy technique implies adequate psychological preparation of the patient, careful insertion of the endoscope with minimal insufflation, and early detection and resolution of loops. Bowel preparation for colonoscopy often requires prolonged preparation and sometimes the addition of other laxatives.

Factors of easy and difficult cecal intubation during unsedated colonoscopy

BACKGROUND AND AIMS

difficulty of cecal intubation should be a main indicator for the need of sedated colonoscopy and skilled endoscopists. The present study aimed to explore the factors associated with easy and difficult cecal intubation in unsedated colonoscopy.

METHODS

all consecutive patients who underwent unsedated colonoscopy at our department by the same endoscopist from December 3, 2020 to August 30, 2022 were retrospectively collected. Age, gender, body mass index (BMI), reasons for colonoscopy, position change, Boston Bowel Preparation Scale score, cecal intubation time (CIT) and major colonoscopic findings were analyzed. CIT < 5 min, CIT 5-10 min and CIT > 10 min or failed cecal intubation were defined as easy, moderate and difficult cecal intubation, respectively. Logistic regression analyses were performed to identify independent factors associated with easy and difficult cecal intubation.

RESULTS

overall, 1,281 patients were included. The proportions of easy and difficult cecal intubation were 29.2 % (374/1,281) and 27.2 % (349/1,281), respectively. Multivariate logistic regression analysis found that age ≤ 50 years, male, BMI > 23.0 kg/m2 and the absence of position change were independently associated with easy cecal intubation, and that age > 50 years, female, BMI ≤ 23.0 kg/m2, position change, and insufficient bowel preparation were independently associated with difficult cecal intubation.

CONCLUSIONS

some convenient factors independently associated with easy and difficult cecal intubation have been identified, which will be potentially helpful to determine whether a colonoscopy should be sedated and a skilled endoscopist should be selected. The current findings should be further validated in large-scale prospective studies.

Dexmedetomidine-Oxycodone combination for conscious sedation during colonoscopy in obese patients: A randomized controlled trial

Background

Obesity is a risk factor for sedation-related respiratory depression during colonoscopy. In a colonoscopy, propofol is frequently used because of its strong sedative and hypnotic properties. However, propofol is associated with marked respiratory depression. The objective of this trial was to investigate the effectiveness and safety of dexmedetomidine plus oxycodone for conscious sedation during colonoscopy in obese patients.

Methods

A total of 120 patients had colonoscopies, and they were divided into two groups at random: Dexmedetomidine and oxycodone were used to sedate group Dex + oxy; while group Pro + oxy received anesthesia with propofol plus oxycodone. Parameters including blood pressure, heart rate, respiration, blood oxygen saturation, injection pain, and recovery time were recorded for both groups.

Results

The incidence of hypoxemia was significantly reduced in group Dex + oxy compared with group Pro + oxy (4.9% vs 20.3%, P = 0.011). Blood pressure was lower, and heart rate was higher in group Pro + oxy compared with group Dex + oxy (P < 0.05). In addition, group Dex + oxy showed a significantly shorter caecal insertion time, recovery time to orientation, and recovery time to walking than group Pro + oxy (P < 0.05). Endoscopist satisfaction scores were significantly higher in group Dex + oxy compared with group Pro + oxy (P = 0.042).

Conclusion

For obese patients, dexmedetomidine plus oxycodone effectively sedate them with few adverse effects, while also reducing colonoscopy operation difficulty by allowing obese patients to reposition. Thus, dexmedetomidine plus oxycodone could be used safely as a conscious sedation method for colonoscopy in obese patients.

Trial registration

The protocol was registered at www.chictr.org.cn (ChiCTR1800017283, July 21, 2018).

Factors affecting cecal intubation time during colonoscopy

In recent years, the morbidity and mortality of colorectal cancer (CRC) have increased significantly in China, and it has become one of the major malignancies that threaten the health of residents. Colonoscopy is the gold standard for the diagnosis of CRC. High-quality colonoscopy can effectively reduce the mortality of CRC. Cecal intubation time (CIT) is one of the indicators to reflect the quality of colonoscopy. Studies have found that many factors can affect CIT. This paper reviews the literature to identify the factors that affect CIT, such as those related to doctors, patients, assistive technologies, and equipment, in order to improve the quality of colonoscopy performed by endoscopists.

A randomized prospective study comparing single-balloon-assisted colonoscopy and cap-assisted colonoscopy in patients with previous incomplete conventional colonoscopy

INTRODUCTION

Cecal intubation may be unsuccessful by conventional colonoscopy in some patients. Single-balloon-assisted colonoscopy (SBC) and cap-assisted colonoscopy (CAC) were studied to solve this problem. There was no head-to-head comparison between them.

METHODS

We conducted a randomized study from 2018 to 2021 to compare cecal intubation rate of SBC and CAC in patients with previous incomplete conventional colonoscopy. We recruited patients with incomplete conventional colonoscopy in two hospitals in Hong Kong. Patients were randomized into SBC group and CAC group in 1:1 ratio. In the case of failure in cecal intubation by allocated method, alternative modality would be performed as rescue.

RESULTS

Forty-four patients were recruited. Cecal intubation rate was superior in SBC group (22/22, 100%) than CAC group (16/22, 72.7%) (P = 0.02). No difference in cecal intubation time, polyp detection rate, and diagnostic gain in area not examined previously. SBC induced less discomfort (modified Gloucester comfort score 2.14 vs 2.63, P = 0.03) with use of comparable amount of midazolam and fentanyl as CAC. For patients failed cecal intubation by CAC, all (n = 6) were rescued successfully by SBC. Body weight, body mass index (BMI), and waist circumference were greater in rescue subgroup. More patients were obese (BMI ≥ 25 kg/m) in rescue subgroup (67% vs 19%). None in rescue subgroup had history of successful cecal intubation by conventional colonoscopy (0% vs 56%, P = 0.046). However, we failed to demonstrate significant association in multivariate analysis owing to small sample size. No adverse event was noted.

CONCLUSION

SBC is superior to CAC in cecal intubation in patients with previous incomplete conventional colonoscopy.

Minimal water exchange by the air-water valve versus left colon water exchange in unsedated colonoscopy: a randomized controlled trial

BACKGROUND

Water exchange colonoscopy is the least painful method for unsedated colonoscopies. Simplified left colon water exchange (LWE) reduces the cecal intubation time but it is difficult to avoid the use of an additional pump. Minimal water exchange (MWE) is an improved novel method that eliminates the need for pumps, but it is not clear whether MWE has the same efficiency as LWE.

METHODS

This was a prospective, randomized, controlled, noninferiority trial conducted in a tertiary hospital. Enrolled patients were randomized 1:1 to the LWE group or MWE group. The primary outcome was recalled insertion pain measured by a 4-point verbal rating scale. Secondary outcomes included adenoma detection rate (ADR), cecal intubation time, volume of water used, and patient willingness to repeat unsedated colonoscopy.

RESULTS

226 patients were included (LWE n = 113, MWE n = 113). The MWE method showed noninferior moderate/severe pain rates compared with the LWE method (10.6 % vs. 9.7 %), with a difference of 0.9 percentage points (99 % confidence interval [CI] -9.5 to 11.3; threshold, 15 %). ADR, cecal intubation time, and willingness to repeat unsedated colonoscopy were not significantly different between the two groups, but the mean volume of water used was significantly less with MWE than with LWE (163.7 mL vs. 407.2 mL; 99 %CI -298.28 to -188.69).

CONCLUSION

Compared with LWE, MWE demonstrated a noninferior outcome for insertion pain, and comparable cecal intubation time and ADR, but reduced the volume of water used and eliminated the need for a water pump.

Impact of an Abdominal Compression Bandage on the Completion of Colonoscopy for Obese Adults: A Prospective Randomized Controlled Trial

METHODS

Eligible patients were randomly allocated into the abdominal bandage and conventional groups during a routine colonoscopy. The primary outcome was CCR.

RESULTS

A total of 250 eligible patients were randomly assigned to the abdominal bandage and conventional groups from January 2021 to April 2021. Eleven patients (five in the abdominal bandage group and six in the conventional group) were excluded due to schedule cancellation after randomization, and 239 patients were eventually included in the final analysis. There were no significant differences between the two groups regarding baseline characteristics (P > 0.05). Furthermore, no significant differences were observed in terms of advanced adenoma detection rate (AADR), polyp detection rate (PDR), bowel preparation scale (BBPS), bubble scale (BS), and withdrawal time between the two groups (P > 0.05). However, compared with the conventional group, the cecal insertion time (CIT) of the abdominal bandage group was significantly shortened (279.00 (234.50-305.75) vs. 421.00 (327.00-485.00), P < 0.001), and the CCR (96.7% vs. 88.2%, P = 0.01) and adenoma detection rate (ADR) (47.5% vs. 32.8%, P < 0.001) were improved. Besides, logistic regression analysis showed that body mass index (BMI) and abdominal compression bandage were associated with CCR.

CONCLUSIONS

Abdominal compression bandages could effectively shorten CIT and improve CCR and ADR for obese patients during a routine colonoscopy. This trial is registered with the Chinese Clinical Trial Registry (No. ChiCTR2100043556).

Factors associated with prolonged cecal insertion time in patients undergoing water exchange colonoscopy

BACKGROUND AND AIM

Water exchange is superior to air insufflation in reducing discomfort and increasing adenoma detection during colonoscopy. However, prolonged cecal insertion time is a drawback. This study aims to investigate the factors affecting cecal insertion during water exchange colonoscopy.

METHODS

We pooled data from five randomized clinical trials that included patients undergoing water exchange colonoscopy. Logistic analysis was performed to determine the independent factors associated with prolonged cecal insertion time (> 15 min).

RESULTS

The cohort included 912 patients (493 men and 419 women) with a median age of 57 years (interquartile range, 49-64 years). The median cecal insertion time was 13.5 min (interquartile range, 10.9-17.0 min). Multivariate logistic regression analysis indicated that female sex, body mass index < 25 kg/m² , a history of constipation, no sedation, less experienced endoscopist, Boston Bowel Preparation Scale score ≤ 6, infused water volume during insertion ≥ 1000 mL, and scope length at the cecum ≥ 85 cm were associated with prolonged cecal insertion time. With increasing volume of infused water (1000-2000 mL), the median cecal insertion time increased gradually from 11.4 to 23.0 min (P < 0.001).

CONCLUSIONS

The current study identified independent factors associated with prolonged cecal insertion time during water exchange colonoscopy. Several factors are modifiable to achieve a shorter insertion time, including better bowel preparation, the use of sedation, more experienced endoscopist, infusing less water during insertion, and maintaining a shorter scope length.

Efficacy and tolerability of colonoscopies in overweight and obese patients: Results from a national database on gastrointestinal endoscopic outcomes

Background and study aims  Gastroenterologists are encountering a rising number of obese patients requiring colonoscopy. Existing literature regarding colonoscopy outcomes in this population is scant and conflicting. We analyzed a nationwide cohort of patients to identify the effects of body mass index (BMI) on colonoscopy success, efficacy, and tolerability. Patients and methods  The Clinical Outcomes Research Initiative (CORI) endoscopic database was queried for all colonoscopies in adults between 2008-2014. Patients were stratified into four cohorts based on BMI classification for comparison. Multivariable analysis was performed to identify the effect of BMI on procedure outcome, efficacy and tolerability. Results  Of 41,401 procedures, 27,696 met study inclusion criteria. Of these, 49.4 % were performed for colorectal cancer screening, most commonly under anesthesia directed sedation. Patient discomfort was the reason for an incomplete colonoscopy in 18.7 % of all cases, and more frequent among the overweight and obese cohorts. An inadequate bowel preparation was most common in the class III obesity cohort. Compared to the normal BMI group, a BMI ≥ 30 and < 40 kg/m ² was associated with an increased odds of an incomplete colonoscopy ( P  = 0.001for overweight, P  = 0.0004 for class I/II obesity), longer procedure ( P  < 0.05 for all) and poorer tolerance ( P  < 0.0001 for class I/II obesity, P  = 0.016 for class III obesity). Anesthesia-administered sedation was more commonly used than endoscopist directed sedation amongst the obese cohort compared with the normal BMI cohort ( P  < 0.0001). Conclusions  Endoscopists should consider the increased odds of incomplete colonoscopy, longer procedures, and poorer tolerance when performing colonoscopy in obese patients to improve clinical management and procedural outcome.

Endocuff Vision improves adenoma detection rate in a large screening-related cohort

Background and study aims  Endocuff Vision (ECV) increases adenoma detection rate (ADR) in randomized clinical trials; however, observational effectiveness data are lacking. We evaluated the effectiveness, safety, and practical aspects of ECV use in a large screening-related real-world cohort. Patients and methods  In this observational study, patients undergoing screening-related colonoscopy from November 2018 to April 2019 comprised the baseline period, and those undergoing it from June to November 2019 comprised the ECV period, where ECV use was discretionary. The primary outcome was ADR, compared: 1) between ECV use and standard colonoscopy across both periods; and 2) between time periods. Secondary outcomes included indication-specific ADR, sessile serrated ADR (SSADR), cecal intubation rate (CIR), procedure times, patient comfort scores, and sedation use. Multilevel logistic regression was performed, yielding adjusted odds ratios (AOR) with 95 % confidence intervals (CIs). Results  In 15,814 colonoscopies across both time periods, ADR was 46.7 % with standard colonoscopy and 54.6 % when ECV was used ( P  < 0.001). Endoscopists used ECV in 77.6 % of procedures in the ECV period, during which overall ADR rose to 53.2 % compared to 46.3 % in the baseline period ( P  < 0.001). ECV use was significantly associated with higher ADR (AOR 1.24, 95 % CI 1.10 to 1.40) after adjusting for relevant covariates including time period. ECV use did not result in lower CIR, longer procedure time, increased sedation use, or poorer comfort scores. Conclusions  ECV use is associated with improved ADR without negatively impacting other key procedure and patient-related factors. Future studies should evaluate the cost-effectiveness of incorporating ECV into routine screening-related practice.

Progress and prospects of artificial intelligence in colonoscopy

Artificial intelligence (AI) is a branch of computer science. As a new technological science, it mainly develops and expands human intelligence through the research of intelligence theory, methods and technology. In the medical field, AI has bright application prospects (for example: imaging, diagnosis and treatment). The exploration of robotic gastroscopy and colonoscopy systems is not only a bold attempt, but also an inevitable trend of AI in the development of digestive endoscopy in the future. Based on the current research findings, this article summarizes the research progress of colonoscopy, and looking forward for the application of AI in colonoscopy.

Factors Affecting Cecal Intubation Time in Colonoscopy: Impact of Obesity

Objective

This study aims to determine the factors that prolong cecal intubation time (CIT) and determine the effect of obesity on CIT measured using multiple indexes.

Methods

Patients who underwent elective colonoscopy between July 10, 2020, and January 20, 2021, were evaluated in this prospective observational study. Age, gender, constipation, bowel preparation, presence of diverticulosis, previous surgery history, auxiliary maneuver and additional analgesic requirement, cecum intubation length (CL) and obesity indices [body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR)] were analyzed. Factors affecting CIT were assessed by both univariate and multivariate logistic regression (LR) analyses.

Results

A total of 512 patients were analyzed. Mean CIT was 5.6 ± 1.6 min, and median CIT was 5.17 min. The CIT median was ≤5.17 min in 264 (51.5%) of the patients, and the CIT median was >5.17 min in 248 (48.5%). In the univariate LR results, young age, constipation, poor bowel preparation, increased CL, additional analgesic requirement, low WHtR, and low BMI (<25 kg/m2) were the factors that prolonged CIT (p <0.05). In the multivariate LR analysis results, WHtR >0.5 and BMI >30 kg/m2 were found to be independent factors that decrease CIT [OR: 0.01 (0.01 0.03) p <0.001; OR: 0.28 (0.13 0.57) p <0.001].

Conclusion

Younger age, low WHtR, low BMI, increased CL, constipation, inadequate bowel preparation, and the use of extra analgesics were found to be associated with longer CIT. When all factors were evaluated together, obesity measured by only WHtR (>0.5) and BMI (>30 kg/m2) were the best predictors of decreased CIT.

Magnetic endoscopic imaging as a rational investment for specific colonoscopies: a systematic review and meta-analysis

BACKGROUND

Magnetic endoscopic imaging (MEI) was regarded as an adjuvant device to improve procedural efficacy and patients' comfort during colonoscopy.

METHODS

Several electronic databases were searched to identify eligible studies. Based on the heterogeneity of included studies, random-effects or fixed-effects models were used to calculate pooled risk ratios (RR), risk difference (RD) or mean difference (MD) along with 95% confidence intervals (CIs).

RESULTS

Twenty-one randomized controlled trials (RCTs) were selected for meta-analysis, with a total of 7,060 patients. Although there is a slightly lower risk of cecal intubation failure with the adjuvant of MEI (RD 3%; P < 0.00001) compared to the control group, the updated studies show no significant benefits. Similarly, the cecal intubation time, pain scores, and loop formation with the adjuvant of MEI did not show any advantages. However, considerable significant benefits were found in the subgroup of technically difficult colonoscopy and inexperienced colonoscopists. Moreover, MEI was associated with lower loop intubation time, lower abdominal compression times, and better lesion localization.

CONCLUSION

The clinical benefits of MEI could be exaggerated. However, MEI has considerable advantages in technically difficult colonoscopies, the assistance for inexperienced colonoscopists, loop resolving, and lesion localization.

Impact of obesity in colorectal endoscopic submucosal dissection: single-center retrospective cohort study

BACKGROUND

When performing colorectal endoscopic submucosal dissection (ESD) in obese patients, technically difficult cases are sometimes experienced because of difficulty with the insertion of the colonoscope, poor scope maneuverability, or an abundance of fat tissue in the submucosal layer. Since the association between obesity and colorectal ESD has not been investigated, we evaluated the clinical impact of obesity in patients who underwent colorectal ESD.

METHODS

We retrospectively reviewed 535 patients who underwent colorectal ESD between April 2012 and February 2019. Patients were divided into three groups based on their body mass index (BMI): a control group (BMI < 25 kg/m²), an overweight group (25 kg/m² ≤ BMI < 30 kg/m²), and an obese group (BMI ≥ 30 kg/m²), and the short-term clinical outcomes were analyzed to assess the safety and difficulty of colorectal ESD.

RESULTS

No significant difference in the procedure times, en bloc resection rates, pathological diagnoses, or complications were seen among the groups. While the amount of sedative per body weight was significantly lower in the group with a higher BMI (flunitrazepam: 1.75 × 10^-2 [1.27 × 10^-2-2.34 × 10^-2] mg/kg vs. 1.48 × 10^-2 [1.08 × 10^-2-2.03 × 10^-2] mg/kg vs. 1.16 × 10^-2 [0.98 × 10^-2-1.54 × 10^-2] mg/kg, P < 0.001; pethidine: 0.63 [0.55-0.72] mg/kg vs. 0.50 [0.46-0.56] mg/kg vs. 0.39 [0.32-0.45] mg/kg, P < 0.001), a reduction in percutaneous arterial oxygen saturation occurred significantly more frequently in the group with a higher BMI (123 [30.2%] vs. 43 [43.9%] vs. 10 [55.6%], P = 0.005). When the procedures were performed by trainees, the number of cases that required a procedure time of longer than 90 min was significantly larger in the group with a higher BMI (27 [10.8%] vs. 14 [21.9%] vs. 3 [25.0%], P = 0.033).

CONCLUSIONS

This study showed that colorectal ESD could be performed safely and effectively in obese patients. However, ESD in obese patients requires attention, particularly to changes in respiratory conditions.

Factors for cecal intubation time during colonoscopy in women: Impact of surgical history

BACKGROUND/AIM

Cecal intubation during colonoscopy is prone to be prolonged in women, which may be related to frequent exposure to pelvic/abdominal surgery. We evaluated the association between Cecal Intubation Time (CIT) and prior episodes of pelvic/abdominal surgery in women.

PATIENTS AND METHODS

A cross-sectional study was conducted on screening participants who underwent colonoscopy. Multivariate regression with parameter estimates (β) was performed to determine the factors affecting CIT, including age, body mass index (BMI), bowel preparation, sedation, diverticulosis, experience of colonoscopists, and a surgical history. Also, subgroup analyses according to type of surgery were performed.

RESULTS

A total of 835 women were enrolled. The mean CIT was 5.82 ± 3.40 min. 323 females (38.7%) had episodes of surgery. The CIT was prolonged in cases performed by non-experienced trainees (β = 3.61, P< 0.001) and with a history of gynecological surgery (β = 0.97, P = 0.001). In the subgroup of non-experienced trainees, lower BMI, poor preparation, and a history of cesarean section significantly prolonged the CIT. Also, the risk for difficult colonoscopy (CIT ≥ 15 min) was increased with a history of cesarean section (odds ratio = 4.43, P= 0.024).

CONCLUSION

A prior episode of gynecological surgery prolonged CIT. Also, cesarean section history was associated with difficult colonoscopy in the examination by non-experienced trainees.

Colonoscopy using back brace support belt: A randomized, prospective trial

Background and Aim

Looping is a major problem in colonoscopy, and it prolongs procedure time. We evaluated the efficacy and safety of an external abdominal compression device (back brace support belt; Maxbelt) with respect to cecal insertion time and other outcomes.

Methods

We performed a prospective study on outpatients undergoing elective colonoscopy in Toyoshima Endoscopy Clinic. Subjects were randomly assigned to groups and were subjected to either Maxbelt (n = 39) or no device (control, n = 38) during colonoscopy. The colonoscopist was blinded to the study. The primary outcome that was observed was insertion time.

Results

The intubation time of the Maxbelt group was shorter than that of the no device group, but the difference was not significant (3.29 vs 4.49 min, P = 0.069). After stratifying by age, the use of Maxbelt significantly decreased cecal intubation time in elderly participants (age ≥ 45) compared to no device group (3.27 vs 5.00 min, P = 0.032). The use of the Maxbelt significantly decreased insertion difficulty encountered by the colonoscopist (P = 0.01). There was no difference in adenoma detection rate, manual pressure, position change, and adverse event.

Conclusions

The use of a back brace support belt could be a viable approach for colonoscopy in elderly patients. (University Hospital Medical Information Network: UMIN000029361).

(Technically) Difficult colonoscope insertion - Tips and tricks

Cecal intubation is a critical aspect of effective, complete colonoscopy. Difficult colonoscopy is most often considered as one in which it is challenging or impossible to reach the cecum. It may be a common occurrence due to patient and/or endoscopist factors. Incomplete colonoscopies should be avoided, since patients in this context present an important prevalence of lesions that escape examination. The approach to successful cecal intubation should depend on characterization of the problem as redundant colon or difficult sigmoid colon. Most patients with a prior incomplete colonoscopy can be colonoscoped successfully, if careful attention is paid to technique, using a variety of scopes, colonoscopy methods and additional equipment. Sufficient time should be allotted to make the attempt.

Efficacy and tolerability of 2-L polyethylene glycol with ascorbic acid versus sodium picosulfate with magnesium citrate: a randomized controlled trial

BACKGROUND/AIM

Previous studies comparing 2-L polyethylene glycol (PEG)-based solution with ascorbic acid (PEG/Asc) with sodium picosulfate/magnesium citrate (SP/MC) drew inconclusive results. This study aimed to compare a 2-L-PEG/Asc with SP/MC by split method in bowel cleansing efficacy, tolerability, and safety and to identify factors influencing inadequate bowel preparation.

METHOD

We performed a prospective randomized, endoscopist-blinded, single-center, controlled trial. The Aronchick scale and Ottawa bowel preparation scale (OBPS) were used to evaluate the bowel cleansing efficacy, and patients' tolerability and preferences were assessed by questionnaire.

RESULTS

In total, 223 patients were randomized to receive 2-L-PEG/Asc (n = 109) or SP/MC (n = 114). There was no significant difference in overall bowel cleansing efficacy between the two groups; however, when analyzing by individual segment, mean bowel cleansing efficacy of right colon showed a trend in favor of SP/MC group than in PEG/Asc group (OBPS; 1.55 ± 0.66 vs. 1.74 ± 0.88, P = 0.08). Furthermore, SP/MC was better tolerated than PEG/Asc based on ease of consumption and preference to receive the agents again in the future. Total adverse events were significantly lower in SP/MC group than PEG/Asc group (47.4 vs. 62.4%, P = 0.031). In multivariate analysis, later colonoscopic starting time was the only independent factor predicting inadequate bowel preparation (OR 1.39, 95% CI 1.156-1.692, P = 0.001).

CONCLUSIONS

There was no significant difference in overall bowel cleansing efficacy between PEG/Asc and SP/MC; however, SP/MC showed better tolerability and safety profile than PEG/Asc. The independent factor for inadequate bowel preparation was later colonoscopic starting time when applied split method.

The impact of visceral adipose tissue as best predictor for difficult colonoscopy and the clinical utility of a long small-caliber scope as rescue

BACKGROUND

There have been many reports about a variety of factors associated with incomplete colonoscopy or difficult colonoscopy with long cecal intubation time (CIT). The aim of this retrospective study was to analyze the factors related to difficult colonoscopy under conscious sedation and demonstrate the clinical utility of a small-caliber scope as rescue by using the data from a large number of subjects who underwent health check-ups.

METHODS

Consecutive 1036 cases over a 12-month period (April 2015 to March 2016) were enrolled and 619 subjects were divided into two groups: Easy colonoscopy (CS) Group (CIT ≤ 10 min); Difficult CS Group (CIT > 10 min or incomplete colonoscopy by a standard scope). The two groups were compared by subjects and colonoscopy characteristics with univariate analysis followed by multivariate logistic regression analysis. Reasons for incomplete colonoscopy were also assessed.

RESULTS

Cecal intubation rate increased from 97.9% to 99.9% (1007/1008) by the rescue scope. Main reasons for incomplete colonoscopy were tortuosity in the left hemicolon (38%), redundancy in the right hemicolon (29%), pain (19%) and fixation (14%). Moreover, 95% (20/21) of rescue colonoscopies were completed without additional sedation. Higher BMI (21 kg/m2 ≤ BMI) and intermediate visceral adipose tissue (VAT) (75 cm2 ≤ VAT < 150 cm2) were significantly associated with easy CS (80.7% vs 19.3%, P = 0.004; 56.3% vs 43.7%, P = 0.001) by univariate analysis. Age, gender, and VAT, not BMI, were independently associated with difficult colonoscopy by multivariate analysis (OR (95% CI), P: 0.964 (0.942, 0.985), 0.001; 1.845 (1.101, 3.091), 0.020; 2.347 (1.395, 3.951), 0.001). Subgroup analysis by gender also showed VAT as the best predictor for both genders.

CONCLUSION

Difficult colonoscopy was significantly associated with advancing age, female gender and, lower (< 75 cm2) or higher (150 cm2 ≤) VAT. These subjects may benefit from having complete and more comfortable colonoscopy examinations by using the small-caliber scope rather than the standard scope.