Strategies to manage the difficult colonoscopy

During endoscopy,an endoscopist is inevitably faced with the occasional“difficult colonoscopy,”in which the endoscopist finds it challenging to advance the endoscope to the cecum.Beyond optimization of technique,with minimized looping,minimal insufflation,sufficient sedation,and abdominal splinting when needed,sometimes additional tools may be needed.In this review,we cover available techniques and technologies to help navigate the difficult colonoscopy,including the ultrathin colonoscope,rigidizing overtube,balloon-assisted colonoscopy and the abdominal compression device.

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

AIM To identify the factors influencing cecal insertion time(CIT) and to evaluate the effect of obesity indices on CIT. METHODS We retrospectively reviewed the data for participants who received both colonoscopy and abdominal computed tomography(CT) from February 2008 to May 2008 as part of a comprehensive health screening program. Age, gender, obesity indices [body mass index(BMI), waist-to-hip circumference ratio(WHR), waist circumference(WC), visceral adipose tissue(VAT)volume and subcutaneous adipose tissue(SAT) volume on abdominal CT], history of prior abdominal surgery, constipation, experience of the colonoscopist, quality of bowel preparation, diverticulosis and time required to reach the cecum were analyzed. CIT was categorized as longer than 10 min(prolonged CIT) and shorter than or equal to 10 min, and then the factors that required a CIT longer than 10 min were examined.RESULTS A total of 1678 participants were enrolled. The mean age was 50.42 ± 9.931 years and 60.3% were men. The mean BMI, WHR, WC, VAT volume and SAT volume were 23.92 ± 2.964 kg/m2, 0.90 ± 0.076, 86.95 ± 8.030 cm, 905.29 ± 475.220 cm3 and 1707.72 ± 576.550 cm3, respectively. The number of patients who underwent abdominal surgery was 268(16.0%). Colonoscopy was performed by an attending physician alone in 61.9% of cases and with the involvement of a fellow in 38.1% of cases. The median CIT was 7 min(range 2-56 min, IQR 5-10 min), and mean CIT was 8.58 ± 5.291 min. Being female, BMI, VAT volume and involvement of fellow were significantly associated with a prolonged CIT in univariable analysis. In multivariable analysis, being female(OR = 1.29, P = 0.047), lower BMI(< 23 kg/m2)(OR = 1.62, P = 0.004) or higher BMI(≥ 25 kg/m2)(OR = 1.80, P < 0.001), low VAT volume(< 500 cm3)(OR = 1.50, P = 0.013) and fellow involvement(OR = 1.73, P < 0.001) were significant predictors of prolonged CIT. In subgroup analyses for gender, lower BMI or higher BMI and fellow involvement were predictors for prolonged CIT in both genders. However, low VAT volume was associated with prolonged CIT in only women(OR = 1.54, P = 0.034).CONCLUSION Being female, having a lower or higher BMI than the normal range, a low VAT volume, and fellow involvement were predictors of a longer CIT.

CO_2 insufflation for potentially diffi cult colonoscopies: Effi cacy when used by less experienced colonoscopists

AIM： To clarify the effectiveness of CO2 insufflation in potentially difficult colonoscopy cases, particularly in relation to the experience level of colonoscopists. METHODS： One hundred twenty potentially difficult cases were included in this study, which involved females with a low body mass index and patients with earlier abdominal and/or pelvic open surgery or previously diagnosed left-side colon diverticulosis. Patients receiving colonoscopy examinations without sedation using a pediatric variable-stiffness colonoscope were divided into two groups based on either CO2 or standard air insuffiation. Both insufflation procedures were also evaluated according to the experience level of the respective colonoscopists who were divided into an experienced colonoscopist （EC） group and a less experienced colonoscopist （LEC） group. Study measurements included a 100-mm visual analogue scale （VAS） for patient pain during and after colonoscopy examinations, in addition to insertion to the cecum and withdrawal times. RESULTS： Examination times did not differ, however, VAS scores in the CO2 group were significantly better than in the air group （P〈 0.001, two-way ANOVA） from immediately after the procedure and up to 2 h later. There were no significant differences between either insufflation method in the EC group （P = 0.29）, however, VAS scores for CO2 insufflation were significantly better than air insufflation in the LEC group （P = 0.023） immediately after colonoscopies and up to 4 h afterwards. CONCLUSION： CO2 insufflation reduced patient pain after colonoscopy in potentially difficult cases when performed by LECs.