Flat and depressed colorectal tumours in a southern Swedish population: a prospective chromoendoscopic and histopathological study

BACKGROUND: Flat and depressed colorectal tumours are common in Japan but are very rare or non-existent in Western countries. AIMS: To study the occurrence of flat colorectal tumours in a southern Swedish population. METHODS: In this prospective study, 371 consecutive European patients were examined by high resolution video colonoscopy combined with chromoendoscopy. The nature of the lesions was determined by histopathological examination. RESULTS: A total of 973 tumours were found; 907 (93.2%) were protruding and 66 (6.8%) were flat or depressed. Of the flat/depressed tumours, five (7.7%) were early adenocarcinomas infiltrating the submucosa. Eleven carcinomas (1.2%) were found among protruding tumours. High grade dysplasia was observed in 18% (n=11) of flat/depressed adenomas in contrast with 7.3% (n=65) of protruding adenomas, and occurred in smaller flat/depressed tumours compared with protruding ones (mean diameter 8 mm v 23 mm, respectively). Furthermore, high grade dysplasia was significantly more common in flat elevated tumours with central depression or in depressed adenomas (35.7%; 5/14) than in flat elevated adenomas (12.8%; 6/47). CONCLUSION: Flat and depressed tumours exist in a Western population. Future studies should address whether or not chromoendoscopy with video colonoscopy is necessary in the search for flat colorectal neoplasms.     

Unsedation colonoscopy can be not that painful: Evaluation of the effect of “Lamaze method of colonoscopy”

AIM: To evaluate the pain relieving effect of intervention with “Lamaze method of colonoscopy” in the process of colonoscopy. METHODS: Five hundred and eighty-five patients underwent colonoscopy were randomly divided into three groups, Lamaze group, anesthetic group and control group. Two hundred and twenty-four patients of Lamaze group, the “Lamaze method of colonoscopy” were practiced in the process of colonoscopy. The Lamaze method of colonoscopy is modified from the Lamaze method of childbirth, which helped patients to relieve pain through effective breathing control. One hundred and seventy-eight patients in anesthetic group accepted sedation colonoscopy. For 183 patients in control group, colonoscopy was performed without any intervention. The satisfactory of colon cleaning, intestinal lesions, intubation time, success ratio, pain grading and complications were recorded. All data were statistically analyzed. RESULTS: There were no significant differences at base line of the three groups (P > 0.05). Anesthetic group shows advantage in intubation time than the other two groups (P < 0.05). Lamaze group shows no advantage in intubation time than that in control group (P > 0.05). The anesthetic group showed an apparent advantage in relieving pain (P < 0.01). Therefore, the “Lamaze method of colonoscopy” performed in colonoscopy could relieve pain effectively comparing with control group (P < 0.05). The patients in anesthetic group had the highest incidence of complications (P < 0.05). CONCLUSION: The performance of the “Lamaze method of colonoscopy” in the process of colonoscopy could relieve patients’ pain, minimize the incidence of complications, and is worthy promotion in clinical practice.     

Wide angle colonoscopy with a prototype instrument: impact on miss rates and efficiency as determined by back-to-back colonoscopies

OBJECTIVE: Polyps are missed during conventional colonoscopy, even with meticulous technique. The aim of this study was to investigate whether a prototype wide angle colonoscope is associated with a reduced miss rate for polyps. METHODS: Two studies were performed. In study 1, a total of 50 patients underwent back-to-back, same-day colonoscopy by a single examiner with the prototype wide angle colonoscope and with a standard colonoscope, with the order of scopes randomized. In study 1, an attempt was made to keep examination time with the two colonoscopes equal. In study 2, a total of 20 patients were examined, 10 by the same colonoscopist who performed study 1 and 10 by a second colonoscopist. In study 2, examiners tried to perform the examinations as quickly as accuracy would allow. RESULTS: In study 1, the miss rate for all polyps was lower with the wide angle colonoscope (20% vs 31%; p = 0.046), although the mean examination time with the wide angle instrument was shorter (6.75 min vs 7.64 min; p = 0.0005). There was no significant difference in detection of adenomas. Polyps, including adenomas, were missed in the peripheral endoscopic field more frequently with the standard colonoscope. In study 2, wide angle colonoscopy was associated with reductions in examination time of 25% and 30% for the two examiners, respectively. Miss rates were the same for one colonoscopist but were higher for the other colonoscopist when the wide angle instrument was used. CONCLUSION: A prototype wide angle colonoscope did not eliminate polyp miss rates. Wide angle colonoscopy has the potential to reduce examination time and improve visualization of the periphery of the endoscopic field of view, but improvements in resolution are needed.     

Intraprocedural bowel cleansing with the Jet Prep cleansing system improves adenoma detection

AIM: To investigate the impact of Jet Prep cleansing on adenoma detection rates.METHODS: In this prospective,randomized,crossover trial,patients were blindly randomized to an intervention arm or a control arm.In accordance with the risk profile for the development of colorectal carcinoma,the study participants were divided into high-risk and low-risk groups.Individuals with just one criterion(age 70 years,adenoma in medical history,and first-degree relative with colorectal cancer) were regarded as high-risk patients.Bowel preparation was performed in a standardized manner one day before the procedure.Participants in the intervention arm underwent an initial colonoscopy with standard bowel cleansing using a 250-m L syringe followed by a second colonoscopy that included irrigation by the use of the Jet Prep cleansing system.The reverse sequence was used in the control arm.The study participants were divided into a high-risk group and a low-risk group according to their respective risk profiles for the development of colorectal carcinoma.RESULTS: A total of 64 patients(34 men and 30 women) were included in the study; 22 were included in the high-risk group.After randomization,30 patients were assigned to the control group(group A) and 34 to the intervention group(group B).The average Boston Bowel Preparation Scale score was 5.15 ± 2.04.The withdrawal time needed for the first step was significantly longer in group A using the Jet Prep system(9.41 ± 3.34 min) compared to group B(7.5 ± 1.92 min).A total of 163 polyps were discovered in 64 study participants who underwent both investigation steps.In group A,49.4% of the polyps were detected during the step of standard bowel cleansing while the miss rate constituted 50.7%.Group B underwent cleansing with the Jet Prep system during the first examination step,and as many as 73.9% of polyps were identified during this step.Thus,the miss rate in group B was a mere 26.1%(P 0.001).When considering only the right side of the colon,the miss rate in group A during the first examination was 60.6%,in contrast to a miss rate of 26.4% in group B(P 0.001).CONCLUSION: Jet Prep is recommended for use during colonoscopy because a better prepared bowel enables a better adenoma detection,particularly in the proximal colon.     

Flat adenomas in the National Polyp Study: is there increased risk for high-grade dysplasia initially or during surveillance?

BACKGROUND & AIMS: The flat adenoma may be a more aggressive pathway in colorectal carcinogenesis. Sessile adenomas from the National Polyp Study cohort were reclassified histopathologically as flat or polypoid and compared with initial and surveillance pathology. METHODS: A total of 933 sessile adenomas detected during 1980-1990 were reclassified as follows: (1) adenoma thickness (AT): < or =1.3 mm, and (2) adenoma ratio (AR): adenoma thickness <2x normal mucosa thickness. Logistic regression was used to assess whether flat adenomas had an effect on risk for high-grade dysplasia initially, and a Cox proportional hazards model assessed the risk for advanced adenomas at surveillance. RESULTS: The analysis encompassed 8401 person-years of follow-up evaluation. AT and AR measures of adenoma flatness were 95% concordant. By the AT measure, flat adenomas (n = 474) represented 27% of all baseline adenomas. Flat adenomas were found to be no more likely to exhibit high-grade dysplasia than sessile (polypoid) or pedunculated adenomas, the odds ratio for high-grade dysplasia was 1.91 (95% confidence interval [CI], 0.66-5.47; P = 0.23) for sessile (polypoid) vs. flat adenomas and 1.78 (95% CI, 0.63-5.02; P = 0.28) for pedunculated vs. flat adenomas adjusted for size, villous component, and location, and corrected for correlation of risk within an individual patient. Patients with flat adenomas at initial colonoscopy were not at greater risk for advanced adenomas at surveillance compared with those with polypoid adenomas only, the odds ratio was 0.76 (95% CI, 0.4-1.42; P = .39), adjusted for multiplicity, age, and family history of colorectal cancer. CONCLUSIONS: Flat adenomas identified in the National Polyp Study cohort at baseline were not associated with a higher risk for high-grade dysplasia initially, or for advanced adenomas at surveillance.     

Long-term outcomes and prognostic factors of patients with obstructive colorectal cancer: A multicenter retrospective cohort study

AIM: To investigate the long-term oncologic outcomes and prognostic factors in patients with obstructive colorectal cancer(CRC) at multiple Japanese institutions.METHODS: We identified 362 patients diagnosed with obstructive colorectal cancer from January 1, 2002 to December 31, 2012 in Yokohama Clinical Oncology Group's department of gastroenterological surgery. Among them, 234 patients with stage Ⅱ/Ⅲ disease who had undergone surgical resection of their primary lesions were analyzed, retrospectively. We report the long-term outcomes, the risk factors for recurrence, and the prognostic factors.RESULTS: The five-year disease free survival and cancer-specific survival were 50.6% and 80.3%, respectively. A multivariate analysis showed the ASAPS(HR = 2.23, P = 0.026), serum Albumin ≤ 4.0 g/d L(HR = 2.96, P = 0.007), T4 tumor(HR = 2.73, P = 0.002) and R1 resection(HR = 6.56, P = 0.02) to be independent risk factors for recurrence. Furthermore, poorly differentiated cancers(HR = 6.28, P = 0.009), a T4 tumor(HR = 3.46, P = 0.011) and R1 resection(HR = 6.16, P = 0.006) were independent prognostic factors in patients with obstructive CRC.CONCLUSION: The outcomes of patients with obstructive CRC was poor. T4 tumor and R1 resection were found to be independent prognostic factors for both recurrence and survival in patients with obstructive CRC.     

结肠镜检查中大肠腺瘤的漏诊率及漏诊相关危险因素

目的 明确结肠镜检查中大肠腺瘤的漏诊率及漏诊腺瘤特征,探讨腺瘤漏诊的相关危险因素.方法 患者在初次结肠镜检查发现并切除腺瘤后120 d内进行结肠镜复查,分析2次结肠镜检查结果.记录2次结肠镜检查所见腺瘤的特征(包括大小、部位、形态、数目及病理)、患者临床特征(包括年龄、性别、结肠镜检查原因、腹部及盆腔手术史、大肠憩室病史及是否行无痛结肠镜检查)及不同的内镜操作医师.分析不同类型腺瘤在结肠镜检查中的漏诊率以及腺瘤特征、患者临床特征和内镜医师的操作水平对腺瘤漏诊的影响.结果 809例患者中271例发生腺瘤漏诊,2次结肠镜检查共检出腺瘤2134颗,漏诊腺瘤425颗,腺瘤总漏诊率为20%(425/2134);平均患者腺瘤漏诊率为33%(271/809).腺瘤体积大者,漏诊率低(P<0.01);乙状结肠、肝曲、盲肠和升结肠部位的腺瘤以及平坦型腺瘤容易漏诊(P<0.05);患者腺瘤数越多在结肠镜检查中腺瘤漏诊率越高(P<0.01);初级内镜医师与有经验内镜医师相比,其漏诊率明显增加(P<0.01).结论 结肠镜检查中存在部分腺瘤漏诊,腺瘤漏诊与腺瘤大小、形态、部位、数目以及结肠镜检查操作医师密切相关.     

结肠镜检查中大肠腺瘤的漏诊率及漏诊相关危险因素

目的 明确结肠镜检查中大肠腺瘤的漏诊率及漏诊腺瘤特征,探讨腺瘤漏诊的相关危险因素.方法 患者在初次结肠镜检查发现并切除腺瘤后120 d内进行结肠镜复查,分析2次结肠镜检查结果.记录2次结肠镜检查所见腺瘤的特征(包括大小、部位、形态、数目及病理)、患者临床特征(包括年龄、性别、结肠镜检查原因、腹部及盆腔手术史、大肠憩室病史及是否行无痛结肠镜检查)及不同的内镜操作医师.分析不同类型腺瘤在结肠镜检查中的漏诊率以及腺瘤特征、患者临床特征和内镜医师的操作水平对腺瘤漏诊的影响.结果 809例患者中271例发生腺瘤漏诊,2次结肠镜检查共检出腺瘤2134颗,漏诊腺瘤425颗,腺瘤总漏诊率为20%(425/2134);平均患者腺瘤漏诊率为33%(271/809).腺瘤体积大者,漏诊率低(P<0.01);乙状结肠、肝曲、盲肠和升结肠部位的腺瘤以及平坦型腺瘤容易漏诊(P<0.05);患者腺瘤数越多在结肠镜检查中腺瘤漏诊率越高(P<0.01);初级内镜医师与有经验内镜医师相比,其漏诊率明显增加(P<0.01).结论 结肠镜检查中存在部分腺瘤漏诊,腺瘤漏诊与腺瘤大小、形态、部位、数目以及结肠镜检查操作医师密切相关.     

Alcohol,postprandial plasma glucose,and prognosis of hepatocellular carcinoma

AIM:To identify factors associated with prognosis of hepatocellular carcinoma(HCC) after initial therapy.METHODS:A total of 377 HCC patients who were newly treated at Katsushika Medical Center,Japan from January 2000 to December 2009 and followed up for > 2 years,or died during follow-up,were enrolled.The factors related to survival were first analyzed in 377 patients with HCC tumor stage T1-T4 using multivariate Cox proportional hazards regression analysis.A similar analysis was performed in 282 patients with tumor stage T1-T3.Additionally,factors associated with the period between initial and subsequent therapy were examined in 144 patients who did not show local recurrence.Finally,214 HCC stage T1-T3 patients who died during the observation period were classified into four groups according to their alcohol consumption and postprandial glucose levels,and differences in their causes of death were examined.RESULTS:On multivariate Cox proportional hazards regression analysis,the following were significantly associated with survival:underlying liver disease stage [non-cirrhosis/Child-Pugh A vs B/C,hazard ratio(HR):0.603,95% CI:0.417-0.874,P = 0.0079],HCC stage(T1/T2 vs T3/T4,HR:0.447,95% CI:0.347-0.576,P < 0.0001),and mean postprandial plasma glucose after initial therapy(< 200 vs ≥ 200 mg/dL,HR:0.181,95% CI:0.067-0.488,P = 0.0008).In T1-T3 patients,uninterrupted alcohol consumption after initial therapy(no vs yes,HR:0.641,95% CI:0.469-0.877,P = 0.0055) was significant in addition to underlying liver disease stage(non-cirrhosis/Child-Pugh A vs B/C,HR:0649,95% CI:0.476-0.885,P = 0.0068),HCC stage(T1 vs T2/T3,HR:0.788,95% CI:0.653-0.945,P = 0.0108),and mean postprandial plasma glucose after initial therapy(< 200 mg/dL vs ≥ 200 mg/dL,HR:0.502,95% CI:0.337-0.747,P = 0.0005).In patients without local recurrence,time from initial to subsequent therapy for newly emerging HCC was significantly longer in the "postprandial glucose within 200 mg/dL group" than the "postprandial glucose > 200 mg/dL group"(l     

Comparative analysis of endoscopic precut conventional and needle knife sphincterotomy

AIM:To compare the efficacy,complications and postprocedural hyperamylasemia in endoscopic pre-cut conventional and needle knife sphincterotomie.METHODS:We performed a retrospective analysis of two pre-cut sphincterotomy(PS) techniques,pre-cut conventional sphincterotomy(PCS),and pre-cut needle knife(PNK).The study included 143 patients;the classic technique was used in 59 patients(41.3%),and the needle knife technique was used in 84 patients(58.7%).We analyzed the efficacy of bile duct access,the need for a two-step procedure,the rates of complications and hyperamylasemia 4 h after the procedure,"endoscopic bleeding" and the need for bleeding control.Furthermore,to assess whether the anatomy of the Vater’s papilla,indications for the procedure or the need for additional procedures could inform the choice of the PS method,we evaluated the additive hyperamylasemia risk 4 h after the procedure with respect to the above mentioned variables.RESULTS:The bile duct access efficacy with PNK and PCS was 100% and 96.6%,respectively,and the difference between the two groups was not significant(P = 0.06).However,the needle knife technique required two-step access significantly more often,in 48.8% vs8.5% of cases(P < 0.0001).The only complication noted was post-ercp pancreatitis(PEP),which was observed in 4/84(4.8%) and 2/59(3.4%) patients submitted to PNK and PSC,respectively;the difference between the two procedures was not significant(P = 0.98).An analysis of other consequences of the techniques yielded the following results in the PNK and PCS groups:hyperamylasemia 4 h after the procedure > 80 U/L,41/84 vs 23/59(P = 0.32);hyperamylasemia 4 h after the procedure > 240 U/L,19/84 vs 11/59(P = 0.71);pancreatic pain,13/84 vs 7/59(P = 0.71);endoscopic bleeding,10/84 vs 8/59(P = 0.97);and the need for bleeding control,10/84 vs 7/59(P = 0.79).In the next part of the study,we analyzed the influence of the method chosen on the risk of hyperamylasemia with respect to an indication for endoscopic retrograde cholangiopancr     

Sporadic duodenal adenoma and the association with colorectal neoplasia: a case-control study

OBJECTIVES: Sporadic duodenal adenomas are an uncommon finding. It is not clear whether patients with sporadic duodenal adenoma have a greater risk for colorectal neoplasia and should undergo colonoscopy. The aims of the present study were to estimate the prevalence of colorectal neoplasia in patients with sporadic duodenal adenoma, and to compare colorectal neoplasia rates in patients with sporadic duodenal adenomas versus those without them.
METHODS: A retrospective case-control study was conducted to identify sporadic duodenal adenoma patients using the databases of two academic and one regional hospital in the Netherlands. Colonoscopic findings in the sporadic duodenal adenoma patients were compared with those of a control group of patients who underwent both gastroduodenoscopy and colonoscopy. Furthermore, the frequency of colorectal cancer in the sporadic duodenal adenoma patients was compared with the population incidence of colorectal cancer.
RESULTS: During the period 1991–2006, 102 patients in total with sporadic duodenal adenomas were identified. Colonoscopy was performed in 49 patients (48%), and colorectal neoplasia was present in 21 of these patients (43%). There was a significantly higher rate of both colorectal neoplasia (43% vs 17%, odds ratio [OR] 3.6, 95% confidence interval [CI] 1.7–7.4) and advanced colorectal adenoma (18% vs 3%, OR 7.8, 95% CI 2.1–29.4) in the patients with sporadic duodenal adenoma compared to that in the control group. Also, the incidence of colorectal cancer was higher in sporadic duodenal adenoma patients compared to that in the population ( P = 0.02).
CONCLUSIONS: Individuals with sporadic duodenal adenomas appear to be at a significantly higher risk of colorectal neoplasia, and therefore should undergo colonoscopy.     

The use of indigocarmine spray increases the colonoscopic detection rate of adenomas

Purpose  It remains controversial whether chromocolonoscopy using indigocarmine increases the detection of colorectal polyps. We aimed to assess the impact of indigocarmine dye spray on the detection rate of adenomas and the feasibility of learning the technique in a Western practice. Methods  400 patients were prospectively allocated into 2 groups; A (n = 200): indigocarmine chromocolonoscopy was performed by a Japanese colonoscopist with expertise in chromoscopy; B (n = 200): initial 100 patients (B-1), a Western colonoscopist with no previous experience of chromoscopy performed conventional colonoscopy, but with at least 10 min observation during colonoscopy withdrawal. In the next 100 patients (B-2), he performed chromocolonoscopy. All polyps found were resected. Regression analysis was used to compare the numbers of polyps detected in groups A, B-1 and B-2, whilst controlling for gender, age, indication and history of colorectal cancer. Results  There were significant differences in the numbers of neoplastic polyps and flat adenomas between groups A and B-1 as well as between B-1 and B-2, but not between A and B-2. There was no significant difference in numbers of advanced lesions. Chromocolonoscopy (A and B-2) detected more neoplastic polyps of ≤5 mm. Conclusion  Chromocolonoscopy increases the detection of neoplastic polyps and flat adenomas, particularly diminutive polyps, but does not increase the detection of advanced lesions.     

结肠镜检查中大肠腺瘤的漏诊率及漏诊相关危险因素

目的 明确结肠镜检查中大肠腺瘤的漏诊率及漏诊腺瘤特征,探讨腺瘤漏诊的相关危险因素.方法 患者在初次结肠镜检查发现并切除腺瘤后120 d内进行结肠镜复查,分析2次结肠镜检查结果.记录2次结肠镜检查所见腺瘤的特征（包括大小、部位、形态、数目及病理）、患者临床特征（包括年龄、性别、结肠镜检查原因、腹部及盆腔手术史、大肠憩室病史及是否行无痛结肠镜检查）及不同的内镜操作医师.分析不同类型腺瘤在结肠镜检查中的漏诊率以及腺瘤特征、患者临床特征和内镜医师的操作水平对腺瘤漏诊的影响.结果 809例患者中271例发生腺瘤漏诊,2次结肠镜检查共检出腺瘤2134颗,漏诊腺瘤425颗,腺瘤总漏诊率为20%（425/2134）;平均患者腺瘤漏诊率为33%（271/809）.腺瘤体积大者,漏诊率低（P〈0.01）;乙状结肠、肝曲、盲肠和升结肠部位的腺瘤以及平坦型腺瘤容易漏诊（P〈0.05）;患者腺瘤数越多在结肠镜检查中腺瘤漏诊率越高（P〈0.01）;初级内镜医师与有经验内镜医师相比,其漏诊率明显增加（P〈0.01）.结论 结肠镜检查中存在部分腺瘤漏诊,腺瘤漏诊与腺瘤大小、形态、部位、数目以及结肠镜检查操作医师密切相关.     

High-grade dysplasia and invasive carcinoma in colorectal adenomas: a multivariate analysis of the impact of adenoma and patient characteristics

BACKGROUND AND AIMS: Most colorectal carcinomas develop from preformed adenomas, but only a minority of adenomas undergo malignant transformation. The clinical significance of polyps of size < 0.5 cm is controversial. The primary goal of this study was to assess the independent risk factors of adenoma and patient characteristics associated with advanced pathological features (APF; i.e. high-grade dysplasia or invasive carcinoma) in colorectal adenomas. A secondary goal was to assess the malignant potential of adenomas with a diameter of < 0.5 cm. PATIENTS AND METHODS: Patients who underwent total colonoscopy at our Medical Department between 1978 and 1996 and had at least one colorectal adenoma were considered for this study. Patients with a history of colorectal cancer, prior polypectomy or colorectal surgery were excluded. A total of 7590 adenomas removed from 4216 patients were included in this analysis. Logistic regression analysis was used to study the impact of different adenoma and patient characteristics on the risk of APF. RESULTS: Size proved to be the most important risk factor for APF. The percentage of adenomas with APF was 3.4%, 13.5% and 38.5% for adenomas of diameter < 0.5 cm, 0.5-1 cm and > 1 cm, respectively. Villous or tubulovillous histology, left-sided location and age >or= 60 years were also associated with APF, whereas sex and number of adenomas had no significant impact. Logistic regression analysis revealed that the risk of an adenoma containing APF was best described by a model incorporating the factors size, location, age, and the age by histology interaction. In the class of adenomas with diameter < 0.5 cm, no invasive carcinoma was found, but 3.4% of adenomas had high-grade dysplasia. CONCLUSIONS: The risk of a colorectal adenoma containing APF can be estimated only by a complex model taking into account several adenoma and patient characteristics. Size, histological type, location and age are independent risk factors for APF in colorectal adenomas. As a considerable percentage of adenomas with diameter < 0.5 cm contain high-grade dysplasia, the clinical conclusion from our study is that all adenomas, including those with diameter < 0.5 cm, should be removed whenever possible.     

Risk factors for colorectal adenomas among immediate family members of patients with colorectal cancer in Taiwan: a case-control study

OBJECTIVES: The incidence of colorectal cancer or adenoma among first-degree relatives of patients with colorectal cancer is significantly high. However, a well defined screening and surveillance consensus has not been developed for these families in Taiwan. We conducted this study to evaluate the colorectal adenoma prevalence pattern in screened immediate family members in Taiwan, and to derive implications for future screening programs. METHODS: A total of 234 immediate family members (aged 51.6 +/- 21.5 yr) of 186 patients with colorectal cancer were offered a colonoscopy. Each relative examined was then paired with two control subjects for age, sex, and symptoms. The prevalence of colorectal adenomas was then compared using multiple logistic regression analysis. RESULTS: The estimated risk of developing adenomas among immediate family members of patients with colorectal cancer was significantly increased (OR = 2.33; 95% CI, 1.43-3.78; p < 0.001). This trend was more striking for men (OR = 2.46; 95% CI, 1.40-4.31; p = 0.001). Immediate family members were at an increased risk for high-risk adenomas (> or = 1.0 cm, with a villous component, and/or with severe dysplasia) (OR = 4.5; 95% CI, 1.91-10.60; p = 0.002), and developed adenomas at an earlier age than did controls. Individuals with index cancer relatives diagnosed at < 50 yr of age or male relatives posed a higher risk of developing colorectal adenomas. CONCLUSIONS: The prevalence of colorectal adenoma in persons with a colorectal cancer family history in Taiwan is similar to that reported in Western countries. This high-risk population should be offered a screening colonoscopy beginning at 40 yr of age.     

Colonoscopic withdrawal technique is associated with adenoma miss rates

BACKGROUND: Clinical studies have documented differences in detection rates of colorectal cancers and adenomas between experienced colonoscopists, the basis of which is unknown. The aim of this study was to determine whether colonoscopic withdrawal technique varies between 2 colonoscopists with known differences in adenoma detection rates. METHODS: Ten consecutive colonoscopic withdrawals by each of the 2 colonoscopists were videotaped and then assessed according to specific criteria by 4 experts blinded to who had performed the colonoscopies. RESULTS: Each of the 4 experts scored the colonoscopist with the lower miss rate significantly higher (p < 0.001) for each of 4 quality criteria: (1) examining the proximal sides of flexures, folds and valves, (2) cleaning and suctioning, (3) adequacy of distention, and (4) adequacy of time spent viewing. CONCLUSION: Higher quality colonoscopic withdrawal technique as determined by expert observers was associated with a colonoscopist with a previously documented lower miss rate for adenomas. Colonoscopic withdrawal technique should be subjected to further study and standards for withdrawal technique should be developed.     

Effect of water exchange method on adenoma miss rate of patients undergoing selective polypectomy: A randomized controlled trial

BackgroundAdenomas may be missed in up to 40% of screening colonoscopies. Although the water exchange (WE) method can improve ADR, as shown in several RCTs, it remains uncertain whether it can increase the detection of missing adenomas compared with standard air-insufflated (AI) colonoscopy.MethodsPatients aged 18–80 years who underwent selective polypectomy were randomly allocated to the WE or AI group. The primary endpoint was the adenoma miss rate (AMR), defined as the number of patients with one or more additional adenomas during the polypectomy procedure divided by the total number of patients in each group.ResultsA total of 450 patients were enrolled, with 225 in each group. The overall AMRs were 45.8% (103/225) in the WE group and 35.6% (80/225) in the AI group (p = 0.035). More patients in the WE group had at least one missed adenoma in the proximal colon (38.2% vs 24.4%, p = 0.002). The adenoma-level miss rate was also higher in the WE group than in the AI group (35.1% vs 29.0%, p = 0.036). Subgroup analysis showed that patients in the WE group had more missed adenomas located in the proximal colon or with flat shapes.ConclusionsThis study confirmed that substantial adenomas were missed in patients undergoing selective polypectomy. The WE method significantly improved the detection of missed adenomas, especially those located in the proximal colon or with flat shapes. (ClnicalTrials.gov number: NCT02880748)     

Does autofluorescence imaging videoendoscopy system improve the colonoscopic polyp detection rate?--a pilot study

OBJECTIVES: Colonoscopy is considered the gold standard for the detection of colorectal polyps; however, polyps can be missed with conventional white light (WL) colonoscopy. The aim of this pilot study was to evaluate whether a newly developed autofluorescence imaging (AFI) system can detect more colorectal polyps than WL.
METHODS: A modified back-to-back colonoscopy using AFI and WL was conducted for 167 patients in the right-sided colon including cecum, ascending and transverse colon by a single experienced colonoscopist. The patient was randomized to undergo the first colonoscopy with either AFI or WL (group A: AFI-WL, group B: WL-AFI). The time needed for both insertion and examination for withdrawal and all lesions detected in the right-sided colon were recorded.
RESULTS: Eighty-three patients were randomized to group A and 84 to group B. The total number of polyps detected by AFI and WL colonoscopy was 100 and 73, respectively. The miss rate for all polyps with AFI (30%) was significantly less than that with WL (49%) ( P = 0.01).
CONCLUSIONS: AFI detects more polyps in the right-sided colon compared to WL colonoscopy.     

Chromoendoscopic colonoscopy for detecting preneoplastic lesions in hereditary nonpolyposis colorectal cancer syndrome.

BACKGROUND & AIMS: In hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, flat and small adenomas are particularly prone to malignant transformation but might be missed by standard colonoscopy. We prospectively studied the diagnostic yield of high-resolution colonoscopy coupled with chromoendoscopy for preneoplastic and neoplastic colorectal lesions in patients with HNPCC syndrome. METHODS: Thirty-six consecutive asymptomatic patients (mean age, 42 years) belonging to HNPCC families and receiving genetic counseling were enrolled in this prospective study. Colonoscopy was performed in 2 steps. Conventional colonoscopy was performed first, followed by a second colonoscopy with chromoendoscopy with indigo carmine (.4%) dye sprayed onto the entire proximal colon. RESULTS: Conventional colonoscopy identified 25 lesions (mean size, 4 +/- 3 mm) in 13 patients. Seven lesions, detected in 5 patients, were adenomas, 3 of which were located in the proximal colon. Chromoendoscopy identified additional 45 lesions (mean size, 3 +/- 1 mm) in 20 patients; most of these lesions were flat and hyperplastic. Eleven additional adenomas were detected in the proximal colon of 8 patients, and 8 of these 11 lesions were flat. The use of chromoendoscopy significantly increased the detection rate of adenomas in the proximal colon, from 3 of 33 patients to 10 of 33 patients (P = .045). CONCLUSION: Relative to conventional colonoscopy, high-resolution colonoscopy with chromoendoscopy markedly improves the detection of adenomas in patients with HNPCC syndrome and might help to prevent colorectal carcinoma in these patients with a very high risk of colorectal cancer.     

Is artificial intelligence the final answer to missed polyps in colonoscopy?

Lesions missed by colonoscopy are one of the main reasons for post-colonoscopy colorectal cancer, which is usually associated with a worse prognosis. Because the adenoma miss rate could be as high as 26%, it has been noted that endoscopists with higher adenoma detection rates are usually associated with lower adenoma miss rates. Artificial intelligence(AI), particularly the deep learning model, is a promising innovation in colonoscopy. Recent studies have shown that AI is not only accurate in colorectal polyp detection but can also reduce the miss rate. Nevertheless, the application of AI in real-time detection has been hindered by heterogeneity of the AI models and study design as well as a lack of long-term outcomes. Herein, we discussed the principle of various AI models and systematically reviewed the current data on the use of AI on colorectal polyp detection and miss rates. The limitations and future prospects of AI on colorectal polyp detection are also discussed.