Small-bowel capsule endoscopy with panoramic view: results of the first multicenter, observational study (with videos)

BACKGROUND AND AIMS

The first small-bowel video-capsule endoscopy (VCE) with 360° panoramic view has been developed recently. This new capsule has wire-free technology, 4 high-frame-rate cameras, and a long-lasting battery life. The aim of the present study was to assess the performance and safety profile of the 360° panoramic-view capsule in a large series of patients from a multicenter clinical practice setting.

METHODS

Consecutive patients undergoing a 360° panoramic-view capsule procedure in 7 European Institutions between January 2011 and November 2015 were included. Both technical (ie, technical failures, completion rate) and clinical (ie, indication, findings, retention rate) data were collected by means of a structured questionnaire. VCE findings were classified according to the likelihood of explaining the reason for referral: P0, low; P1, intermediate; P2, high.

RESULTS

Of the 172 patients (94 men; median age, 68 years; interquartile range, 53-75), 142 underwent VCE for obscure (32 overt, 110 occult) GI bleeding (OGIB), and 28 for suspected (17) or established (2) Crohn's disease (CD). Overall, 560 findings were detected; 252 were classified as P2. The overall diagnostic yield was 40.1%; 42.2% and 30.0% in patients with OGIB and CD, respectively. The rate of complete enteroscopy was 90.2%. All patients but one, who experienced capsule retention (1/172, 0.6%), excreted and retrieved the capsule. VCE failure occurred in 4 of 172 (2.3%) patients because of technical problems.

CONCLUSIONS

This multicenter study, conducted in the clinical practice setting and based on a large consecutive series of patients, showed that the diagnostic yield and safety profile of the 360° panoramic-view capsule are similar to those of forward-view VCEs.

Can we improve the detection rate and interobserver agreement in capsule endoscopy?

BACKGROUND

Data about strategies for improving the diagnostic ability of capsule endoscopy readers are lacking.

AIM

(1) To evaluate the detection rate and the interobserver agreement among readers with different experience; (2) to verify the impact of a specific training (hands-on training plus expert tutorial) on these parameters.

METHODS

17 readers reviewed 12 videos twice; between the two readings they underwent the training. The identified small bowel findings were described by a simplified version of Structured Terminology and classifies as clinically significant/non-significant. Findings identified by the readers were compared with those identified by three experts (Reference Standard).

RESULTS

The Reference Standard identified 26 clinically significant findings. The mean detection rate of overall readers for significant findings was low (about 50%) and did not change after the training (46.2% and 46.4%, respectively). There was no difference in the detection rate among readers with different experience. The interobserver agreement with the Reference Standard in describing significant findings was moderate (k = 0.44; CI95%: 0.39-0.50) and did not change after the training (k = 0.44; CI95%: 0.38-0.49) or stratifying readers according to their experience.

CONCLUSIONS

Both the interobserver agreement and the detection rate of significant findings are low, regardless of the readers' experience. Our training did not significantly increase the performance of readers with different experience.

Superiority of neural networks over discriminant functions for thalassemia minor screening of red blood cell microcytosis

We compared the utility of screening red blood cell (RBC) microcytosis for thalassemia minor using backpropagation neural networks, linear and quadratic discriminant functions, and previously reported discriminant functions based on RBC indices. Screening classification of cases representing possible thalassemia minor (n = 60) and non-thalassemic microcytosis (n = 60) were studied. Among eight RBC indices evaluated, the RBC count was the best univariate discriminant function. Multivariate stepwise discriminant analysis selected the RBC count, the mean corpuscular volume, and the percentage of hypochromic cells as the most discriminatory subset of RBC indices. Optimized linear and quadratic discriminant functions based on these indices performed better than seven previously reported multivariate discriminant functions. However, optimized neural networks were superior to all other discriminant methods studied, averaging 94.1% discriminant efficiency, 94.2% sensitivity, and 94.2% specificity.

Prophylactic sclerotherapy in high-risk cirrhotics selected by endoscopic criteria. A multicenter randomized controlled trial

Controlled trials of sclerotherapy for the prevention of the first variceal hemorrhage in cirrhotics have given conflicting results. In the present study, 106 cirrhotics were randomized to sclerotherapy (55 patients) or control group (51 patients). Admission criteria were no history of previous variceal bleeding and the presence of high-risk varices, i.e., a variceal score less than or equal to 0 according to Beppu et al. Sclerotherapy sessions were performed at time zero, 7 days, 30 days, and then monthly until eradication. Follow-up endoscopies were performed at 6-month intervals thereafter. Control patients underwent repeat endoscopy at 6-month intervals. Bleeding episodes were treated by sclerotherapy in both groups, whenever possible. Mean follow-up was 24 months. Analysis of the results was performed by the intention-to-treat method. Variceal bleeding occurred in 19 sclerotherapy patients (34.5%) and in 17 controls (35.4%, P = NS). Overall mortality was 34.5% in sclerotherapy patients and 50% in controls (P = NS). Seven of the 19 sclerotherapy patients (36.8%) and 11 of the 17 controls (64.7%) who bled died of hemorrhage (P less than 0.05, log-linear model). It is concluded that prophylactic sclerotherapy does not reduce the incidence of first variceal bleeding in cirrhotics. However, there seems to be a trend toward a lower bleeding-related mortality in sclerotherapy patients than in controls.

Eradication of esophageal varices by endoscopic sclerotherapy: how much is enough?

To clarify if complete eradication of varices from the lower esophagus by endoscopic sclerotherapy is really essential to prevent rebleeding, or if reduction of varices below a certain size can be considered a sufficient result, we compared the fate of 72 patients in whom sclerotherapy was stopped after one of the following endoscopic endpoints was reached: complete eradication (15 patients, group 1), partial eradication with residual small white varices (32 patients, group 2), and partial eradication with residual small blue varices (25 patients, group 3). The incidence of variceal recurrences and recurrent bleeding over a median follow-up of 17 months after stopping sclerotherapy did not differ significantly in the three groups. Analysis of the time course of variceal recurrences showed that the recurrence-free interval was almost identical in group 1 and group 2 patients (13 and 14 months, respectively). Group 3 patients had a shorter recurrence-free interval (8.3 months), but the difference was not statistically significant. We conclude that sclerotherapy can be stopped safely when either complete eradication or reduction of varices to small white columns is obtained.

Activation of coagulation in cirrhotics after endoscopic variceal schlerotherapy

To investigate the occurrence and extent of activation of coagulation after endoscopic variceal sclerotherapy (EVS), we performed serial measurements of conventional coagulation tests [prothrombin time (PT), partial thromboplastin time (PTT), platelets, and fibrinogen], and of plasma fibrinopeptide A (FPA) in 39 cirrhotic patients undergoing 55 sessions of elective EVS. Thrombin (20 U/ml) and sodium morrhuate 5% were used in sequence as sclerosants on 34 occasions. In the remaining 21 sessions, sodium morrhuate 5% alone was used. Conventional coagulation tests did not change significantly after EVS, regardless of the type of treatment. Basal plasma FPA levels were abnormally high in about 50% of patients. After EVS, plasma FPA increased sharply in 37/39 patients (95%), returning to baseline values in most of them within 24 h. We conclude that transient systemic activation of blood coagulation occurs after EVS. Such activation can be detected only by sensitive methods such as FPA assay, and has no effect on conventional coagulation tests. This, and the absence of any clinical EVS-related coagulation disorder in our patients, suggests that activation of coagulation should not be a major concern for patients undergoing EVS.