The impact of reader fatigue on the accuracy of capsule endoscopy interpretation

BACKGROUND AND AIMS

Capsule endoscopy (CE) interpretation requires the review of many thousands of images, with lesions often limited to just a few frames. In this study we aim to determine whether lesion detection declines according to the number of capsule videos read.

METHODS

32 participants, 16 of which were novices (NR) and 16 experienced (ER) capsule readers took part in this prospective evaluation study. Participants read six capsule cases with a variety of lesions, in a randomly assigned order during a single sitting. Psychomotor Vigilance Tests and Fatigue Scores were recorded prior to commencing and then after every two capsules read. Changes in lesion detection and measures of fatigue were assessed across the duration of the study.

RESULTS

Mean agreement with the predefined lesions was 48.3% (SD:16.1), and 21.3% (SD:15.1) for the experienced and novice readers respectively. Lesion detection declined amongst experienced reader after the first study (p = 0.01), but remained stable after subsequent capsules read, while NR accuracy was unaffected by capsule numbers read. Objective measures of fatigue did not correlate with reading accuracy.

CONCLUSION

This study demonstrates that reader accuracy declines after reading just one capsule study. Subjective and objective measures of fatigue were not sufficient to predict the onset of the effects of fatigue.

Argon plasma coagulation for Barrett's esophagus with low-grade dysplasia: a randomized trial with long-term follow-up on the impact of power setting and proton pump inhibitor dose

BACKGROUND

This study evaluated the impact of power setting and proton pump inhibitor (PPI) dose on efficacy and safety of argon plasma coagulation (APC) of Barrett's esophagus (BE) with low-grade dysplasia (LGD). METHODS : 71 patients were randomized to APC with power set at 90 W or 60 W followed by 120 mg or 40 mg omeprazole. The primary outcome was the rate of complete (endoscopic and histologic) ablation of BE at 6 weeks. Secondary outcomes included safety and long-term efficacy. RESULTS : Complete ablation rate in the 90 W/120 mg, 90 W/40 mg, and 60 W/120 mg groups was 78 % (18/23; 95 % confidence interval [CI] 61-95), 60 % (15/25; 95 %CI 41-79), 74 % (17/23; 95 %CI 56-92), respectively, at 6 weeks and 70 % (16/23; 95 %CI 51-88), 52 % (13/25; 95 %CI 32-72), and 65 % (15/23; 95 %CI 46-85) at 2 years post-treatment (differences not significant). Additional APC was required in 28 patients (23 residual and 5 recurrent BE). At median follow-up of 108 months, 66/71 patients (93 %; 95 %CI 87-99) maintained complete ablation. No high-grade dysplasia or adenocarcinoma developed. Overall, adverse events (97 % mild) did not differ significantly between groups. Chest pain/discomfort was more frequent in patients receiving 90 W vs. 60 W power (P < 0.001). One patient had esophageal perforation and two developed stenosis.

CONCLUSIONS

APC power setting and PPI dose did not impact efficacy and safety of BE ablation. Complete ablation of BE with LGD was durable in > 90 % of patients, without any evidence of neoplasia progression in the long term.

Use of rapid reading software to reduce capsule endoscopy reading times while maintaining accuracy

BACKGROUNDS AND AIMS

A typical capsule endoscopy (CE) case generates tens of thousands of images, with abnormalities often confined to a just few frames. Omni Mode is a novel EndoCapsule software algorithm (Olympus, Tokyo, Japan) that proposes to intelligently remove duplicate images while maintaining accuracy in lesion detection.

METHODS

This prospective multicenter study took place across 9 European centers. Consecutive, unselected CE cases were read conventionally in normal mode, with every captured frame reviewed. Cases were subsequently anonymized and randomly allocated to another center where they were read using Omni Mode. Detected lesions and reading times were recorded, with findings compared between both viewing modes. The clinical significance of lesions was described according to the P classification (P0, P1, and P2). Where a discrepancy in lesion detection in either mode was found, expert blinded review at a consensus meeting was undertaken.

RESULTS

The patient population undergoing CE had a mean age of 49.5 years (range, 18-91), with the investigation of anemia or GI bleeding accounting for 71.8% of cases. The average small-bowel transit time was 4 hours, 26 minutes. The mean reading time in normal mode was 42.5 minutes. The use of Omni Mode was significantly faster (P < .0001), with an average time saving of 24.6 minutes (95% confidence interval, 22.8-26.9). The 2127 lesions were identified and classified according to the P classification as P0 (1234), P1 (656), and P2 (237). Lesions were identified using both reading modes in 40% (n = 936), and 1186 lesions were identified by either normal or Omni Mode alone. Normal mode interpretation was associated with 647 lesions being missed, giving an accuracy of .70. Omni Mode interpretation led to 539 lesions being missed, with an accuracy of .75. There was no significant difference in clinical conclusions made between either reading mode.

CONCLUSIONS

This study shows that CE reading times can be reduced by an average of 40%, without any reduction in clinical accuracy.

Adenocarcinoma risk in patients registered with Polish Barrett's Oesophagus Registry

Barrett's Oesophagus (BO) is a complication of chronic gastro-oesophageal reflux disease (GORD) and is a major risk factor for oesophageal adenocarcinoma. Current guidelines are based on data showing a 0.5% annual malignancy progression rate. The Polish Barrett's Oesophagus Registry (POBOR) was established to characterize Polish patients with BO and estimate the risk of malignant progression. POBOR was established in 1999 after a dedicated training of endoscopists and histopathologists. Physicians registered patients using a dedicated registry form. After excluding patients known to have endoscopic treatment for BO, follow-up <1 year and adenocarcinoma found at index endoscopy we have linked patients personal identification numbers (PESEL) with the National Cancer Registry to identify those with a diagnosis of oesophageal or gastric cardia adenocarcinoma. In total, 843 patients were registered [609 men (72.2%), male to female ratio 2.6:1] with median age at diagnosis of 56 years (IQR:47-67). Long segment BE was found at index endoscopy in 294 patients (39.4%) whereas low grade dysplasia in 147 (17.4%). 112 patients (13.3%) fulfilled the exclusion criteria and the remaining 731 were followed for a median of 9.8 years (IQR: 9.3-10.0). After 6779 patient-years, 6 adenocarcinomas were diagnosed yielding an incidence rate of 0.89 per 1000 patients-years (95% confidence interval [CI 0.40-1.97]) which corresponds to annual malignancy progression rate of less than 0.1%. The malignancy rate in patients with low grade dysplasia was 3.70 per 1000 patient-years (95% CI 1.39-9.85). In Polish BO patients the risk of malignant progression was lower than previously reported. It was notably higher in patients with low grade dysplasia than in those with no dysplasia at index endoscopy, which may warrant strict surveillance in these patients.

Leadership training to improve adenoma detection rate in screening colonoscopy: a randomised trial

OBJECTIVE

Suboptimal adenoma detection rate (ADR) at colonoscopy is associated with increased risk of interval colorectal cancer. It is uncertain how ADR might be improved. We compared the effect of leadership training versus feedback only on colonoscopy quality in a countrywide randomised trial.

DESIGN

40 colonoscopy screening centres with suboptimal performance in the Polish screening programme (centre leader ADR ≤ 25% during preintervention phase January to December 2011) were randomised to either a Train-Colonoscopy-Leaders (TCLs) programme (assessment, hands-on training, post-training feedback) or feedback only (individual quality measures). Colonoscopies performed June to December 2012 (early postintervention) and January to December 2013 (late postintervention) were used to calculate changes in quality measures. Primary outcome was change in leaders' ADR. Mixed effect models using ORs and 95% CIs were computed.

RESULTS

The study included 24,582 colonoscopies performed by 38 leaders and 56,617 colonoscopies performed by 138 endoscopists at the participating centres. The absolute difference between the TCL and feedback groups in mean ADR improvement of leaders was 7.1% and 4.2% in early and late postintervention phases, respectively. The TCL group had larger improvement in ADR in early (OR 1.61; 95% CI 1.29 to 2.01; p<0.001) and late (OR 1.35; 95% CI 1.10 to 1.66; p=0.004) postintervention phases. In the late postintervention phase, the absolute difference between the TCL and feedback groups in mean ADR improvement of entire centres was 3.9% (OR 1.25; 95% CI 1.04 to 1.50; p=0.017).

CONCLUSIONS

Teaching centre leaders in colonoscopy training improved important quality measures in screening colonoscopy.

TRIAL REGISTRATION NUMBER

NCT01667198.

Water exchange versus carbon dioxide insufflation in unsedated colonoscopy: a multicenter randomized controlled trial

BACKGROUND AND STUDY AIMS

Compared with air insufflation, water exchange and carbon dioxide (CO2) insufflation have been shown to reduce colonoscopy discomfort; however, head-to-head studies of the two methods are lacking. We aimed to compare water exchange and CO2 insufflation directly with regard to pain during primary unsedated colonoscopy.

METHODS

Patients willing to undergo unsedated colonoscopy at three centers in Norway and Poland were randomized 1:1 to water exchange or CO2 insufflation during colonoscope insertion. Patients were blinded to group allocation. The primary end point was the proportion of patients reporting moderate or severe procedural pain on a 4-point verbal rating scale (VRS-4) at discharge. Secondary outcomes included the proportion of patients reporting no pain on the VRS-4.

RESULTS

A total of 473 patients were randomized. A discharge pain questionnaire was completed by 226 of 234 patients (97 %) in the water exchange group versus 226 of 239 patients (95 %) in the CO2 group (P = 0.37). Moderate or severe pain was reported by 47 of 226 patients (21 %) in the water exchange group versus 60 of 226 patients (27 %) in the CO2 group (P = 0.15). No pain was reported by 100 of 226 patients (44 %) and 69 of 226 patients (31 %) in the water exchange and CO2 groups, respectively (P = 0.003). On-demand sedation was used in 15 patients (6 %) in each group (P = 0.95).

CONCLUSIONS

There was no significant reduction in moderate or severe pain in a comparison of water exchange with CO2 insufflation. The secondary outcome of no pain was significantly more frequent in the water exchange group. Clinical trials registry number: NCT01633333.

Small bowel tumors detected and missed during capsule endoscopy: Single center experience

AIM: To characterize small bowel (SB) tumors detected by capsule endoscopy (CE), and identify missed tumors.

METHODS: The study included 145 consecutive patients in whom 150 CEs were performed. Following CE, the medical records of the study population were reviewed. Results of double- or single-balloon enteroscopy performed after CE and the results of surgery in all patients operated on were retrieved. The patients were contacted through telephone interviews or postal mail. In addition, the national cancer registry and the polish clinical gastrointestinal stromal tumor (GIST) Registry were searched to identify missed neoplasms.

RESULTS: Indications for CE included overt and occult obscure gastrointestinal bleeding (n = 81, 53.7%), anemia (n = 19, 12.7%), malabsorption (n = 18, 12%), abnormal CB follow through (n = 9, 6%), abdominal pain (n = 7, 5%), celiac disease (n = 5, 3%), neuroendocrine tumor (n = 3, 2%), Crohn’s disease (n = 2, < 2%), Peutz-Jeghers syndrome (n = 2, < 2%), other polyposes (n = 2, < 2%), and diarrhea (n = 2, < 2%). The capsule reached the colon in 115 (76.6%) examinations. In 150 investigations, CE identified 15 SB tumors (10%), 14 of which were operated on or treated endoscopically. Malignancies included metastatic melanoma (n = 1), adenocarcinoma (n = 2), and GIST (n = 3). Benign neoplasms included dysplastic Peutz-Jeghers polyps (n = 4). Non-neoplastic masses included venous malformation (n = 1), inflammatory tumors (n = 2), and a mass of unknown histology (n = 1). During the follow-up period, three additional SB tumors were found (2 GISTs and one mesenteric tumor of undefined nature). The National Cancer Registry and Polish Clinical GIST Registry revealed no additional SB neoplasms in the post-examination period (follow-up: range 4.2-102.5 mo, median 39 mo). The sensitivity of CE for tumor detection was 83.3%, and the negative predictive value was 97.6%. The specificity and positive predictive value were both 100%.

CONCLUSION: Neoplasms may be missed by CE, especially in the proximal SB. In overt obscure gastrointestinal bleeding, complementary endoscopic and/or radiologic diagnostic tests are indicated.

Randomized comparison of three palliative regimens including brachytherapy, photodynamic therapy, and APC in patients with malignant dysphagia (CONSORT 1a) (Revised II)

OBJECTIVES

Because most esophageal cancers are diagnosed at an advanced stage, a majority of patients require palliative dysphagia treatment. Dysphagia severity and the need for repeated re-canalization procedures significantly affect patients' quality of life (QoL). The aim of this study was to establish whether combining argon plasma coagulation (APC) of the neoplastic esophageal tissue with another re-canalization method results in a longer dysphagia-free period compared with APC alone.

METHODS

We conducted a randomized trial in 93 patients with malignant dysphagia. Patients were followed until death. We compared three regimens of esophageal re-canalization; APC combined with high dose rate (HDR) brachytherapy, APC combined with photodynamic therapy (PDT), and APC alone. The primary outcome measure was the dysphagia-free period following randomization. Secondary measures were survival, QoL, treatment-associated complications, and treatment tolerance. A per-protocol analysis was carried out.

RESULTS

The time to first dysphagia recurrence was significantly different between each combination treatment group and the control group (overall test: P=0.006; HDR vs. control, log-rank P=0.002, PDT vs. control, log-rank P=0.036), but not different between the combination groups (HDR vs. PDT, log-rank P=0.36). The median time to first dysphagia recurrence was 88, 59, and 35 days in the HDR, PDT, and control groups, respectively. There was no difference in overall survival between the study groups (P=0.27). No deaths, perforations, hemorrhages, or fistula formations were attributed to treatment. The only major complication was fever, occurring in three PDT patients. Minor complications were observed significantly more often in the combination treatment groups and included pain in both groups, transient dysphagia worsening, and skin sensitivity in the PDT group. The QoL 30 days after treatment in the HDR group was significantly better than in the other groups.

CONCLUSIONS

In patients with inoperable esophageal cancer, palliative combination treatment of dysphagia with APC and HDR or PDT was significantly more efficient than APC alone, and was safe and well tolerated. APC combined with HDR resulted in fewer complications and better QoL than APC with PDT or APC alone (CONSORT 1b).

Vascular lesions of the gastrointestinal tract

Classification of vascular abnormalities of the gastrointestinal tract on the basis of anatomy and pathophysiology has recently been suggested. Angiodysplasia, an example of an arteriovenous lesion, may cause either acute or chronic bleeding. Diagnosis may be difficult. High-quality standard endoscopy, capsule endoscopy, and double-balloon enteroscopy are most efficacious. Therapy using argon plasma coagulation is currently preferred. Pharmacological therapy has been employed, but a final conclusion about its efficacy cannot yet be drawn. Dieulafoy lesion, an arterial type of vascular abnormality, is rare but serious. It can be responsible for severe haemorrhage. Mechanical endoscopic methods are the most efficacious. Gastric antral vascular ectasia (GAVE), a capillary lesion, can be safely biopsied; it coincides with several diseases (including liver cirrhosis), may cause chronic iron-deficiency anaemia, and is best treated by argon plasma coagulation. Haemangiomas, benign neoplastic lesions, usually occur as part of other specific syndromes; they are difficult to manage due to the multiplicity and size of the lesions.

Endosonography versus helical computed tomography for locoregional staging of gastric cancer

BACKGROUND AND STUDY AIMS

Endosonography (EUS) has been shown to be more accurate than incremental computed tomography (CT) in the local (T) and regional (N) staging of gastric carcinoma; however, EUS has never been compared with helical CT (HCT). The fifth edition of the TNM classification changed the guidelines for N-staging of gastric carcinoma. The accuracy of imaging methods in this new system remains unknown.

PATIENTS AND METHODS

Staging accuracy of EUS and HCT were compared prospectively with pathological or intraoperative findings in 88 gastric carcinoma patients. Staging was done according to the fourth and fifth editions of the TNM classification. EUS was done with a radial echo endoscope, and HCT with a scanner with two rows of detectors (two-phase contrast-enhanced scanning of a water-filled stomach).

RESULTS

The T-staging accuracy of EUS (63 %, CI 52 - 73 %) was superior to the accuracy of HCT (44 %, CI 34 - 55 %; P = 0.021). N-staging accuracy of both methods was similar when the fourth edition of the TNM classification was used (EUS 47 %, CI 34 - 60 %; HCT 52 %, CI 38 - 65 %). However, HCT was more accurate than EUS when the fifth edition of the classification was applied (EUS 30 %, CI 18 - 43 %, HCT 47 %, CI 34 - 60 %; P = 0.044). The accuracy of detection of lymph node metastases was similar for both methods (EUS 67 %, CI 54 - 78 %; HCT 77 %, CI 64 - 86 %).

CONCLUSIONS

EUS is more accurate than HCT in the T-staging of gastric carcinoma. Both methods are comparable for N-staging, when this is done according to the older, fourth edition of the TNM classification. If the fifth edition is used, EUS is less accurate than HCT.

Endoscopic ultrasonography for prediction of postpolypectomy bleeding in patients with large nonpedunculated rectosigmoid adenomas

BACKGROUND AND STUDY AIMS

Case reports suggest that endosonographic visualization of blood vessels in a gastric polyp may be predictive of risk of postpolypectomy bleeding; however, this issue has never been studied in patients with colorectal adenomas.

PATIENTS AND METHODS

Endosonography (EUS) was performed prior to endoscopic polypectomy of 42 large (>/= 20 mm) nonpedunculated adenomatous polyps. The median diameter of the polyps was 30 mm (range 20-100 mm); 35 were located in the rectum and seven in the sigmoid colon. During EUS both the polyp and the bowel wall underneath were searched for the presence of vessels, which were defined as longitudinal/tortuous or round/oval echo-free structures >/= 2 mm in diameter.

RESULTS

The polyp was visualized adequately in 39 cases; three cases were excluded from analysis due to inadequate visualization. In eight polyps (20.5%, group 1) EUS revealed vessels measuring 2-4 mm; in 31 polyps (79.5 %, group 2) no vessels were found. The postpolypectomy bleeding incidence (per polyp treated) was 12.5% in group 1 and 12.9 % in group 2 (P>0.05).

CONCLUSIONS

In this small series of patients with large nonpedunculated rectosigmoid adenomas, the EUS image of the polyp was not predictive of postpolypectomy bleeding. The detection of vessels on EUS did not increase the risk for bleeding; however, the sample size was to small to draw definite conclusions. The absence of vessels on EUS did not rule out the possibility of bleeding.

Argon plasma coagulation after piecemeal polypectomy of sessile colorectal adenomas: long-term follow-up study

BACKGROUND AND STUDY AIMS

The aim of this study was to evaluate prospectively the long-term outcomes of using argon plasma coagulation (APC) as an adjunct to piecemeal polypectomy of large sessile colorectal adenomas.

PATIENTS AND METHODS

A total of 77 patients with 82 sessile colorectal adenomas (median size 2.9 cm, range 1.5 - 8.0 cm) underwent snare piecemeal polypectomy. Patients in whom polypectomy was complete received no further treatment (polypectomy group; n = 14). When polypectomy was incomplete, additional treatment with APC was started either immediately or 1 - 3 months after the last polypectomy session (polypectomy + APC group; n = 63). Patients were followed (by endoscopy and biopsy) at regular intervals.

RESULTS

Histologically proven adenoma eradication was achieved in 100 % of patients (14/14) in the polypectomy group and in 90 % of patients (57/63) in the polypectomy + APC group (two patients died of unrelated causes before adenoma was eradicated, two underwent operation because cancer was detected in the polyp treated, and two underwent operation because of endoscopic treatment failure). The adenoma recurrence rate was 14 % in both the polypectomy and polypectomy + APC groups. All recurrences except one occurred during the first year of follow-up and all were successfully re-treated endoscopically. A total of 69 patients in whom long-term follow-up data are available are free from adenoma at a median follow-up of 37 months (range 12 - 80). No major complications of endoscopic treatment occurred. In seven cases (9 %) the polyp was eventually shown to be malignant; in two of these patients the diagnosis of cancer was delayed as a result of unsuccessful endoscopic treatment.

CONCLUSIONS

APC used in combination with piecemeal polypectomy of large colorectal adenomas is an effective and safe method of therapy, provided patient selection is careful and follow-up close.