Jejunal gastrointestinal stromal tumor missed by three capsule endoscopies

Application of wireless power transmission systems in wireless capsule endoscopy: an overview

Wireless capsule endoscopy (WCE) is a promising technology for direct diagnosis of the entire small bowel to detect lethal diseases, including cancer and obscure gastrointestinal bleeding (OGIB). To improve the quality of diagnosis, some vital specifications of WCE such as image resolution, frame rate and working time need to be improved. Additionally, future multi-functioning robotic capsule endoscopy (RCE) units may utilize advanced features such as active system control over capsule motion, drug delivery systems, semi-surgical tools and biopsy. However, the inclusion of the above advanced features demands additional power that make conventional power source methods impractical. In this regards, wireless power transmission (WPT) system has received attention among researchers to overcome this problem. Systematic reviews on techniques of using WPT for WCE are limited, especially when involving the recent technological advancements. This paper aims to fill that gap by providing a systematic review with emphasis on the aspects related to the amount of transmitted power, the power transmission efficiency, the system stability and patient safety. It is noted that, thus far the development of WPT system for this WCE application is still in initial stage and there is room for improvements, especially involving system efficiency, stability, and the patient safety aspects.

Evaluation of 4 three-dimensional representation algorithms in capsule endoscopy images

AIM: To evaluate the three-dimensional (3-D) representation performance of 4 publicly available Shape-from-Shading (SfS) algorithms in small-bowel capsule endoscopy (SBCE).

METHODS: SfS techniques recover the shape of objects using the gradual variation of shading. There are 4 publicly available SfS algorithms. To the best of our knowledge, no comparative study with images obtained during clinical SBCE has been performed to date. Three experienced reviewers were asked to evaluate 54 two-dimensional (2-D) images (categories: protrusion/inflammation/vascular) transformed to 3-D by the aforementioned SfS 3-D algorithms. The best algorithm was selected and inter-rater agreement was calculated.

RESULTS: Four publicly available SfS algorithms were compared. Tsai’s SfS algorithm outperformed the rest (selected as best performing in 45/54 SBCE images), followed by Ciuti’s algorithm (best performing in 7/54 images) and Torreão’s (in 1/54 images). In 26/54 images; Tsai’s algorithm was unanimously selected as the best performing 3-D representation SfS software. Tsai’s 3-D algorithm superiority was independent of lesion category (protrusion/inflammatory/vascular; P = 0.678) and/or CE system used to obtain the 2-D images (MiroCam^®/PillCam^®; P = 0.558). Lastly, the inter-observer agreement was good (kappa = 0.55).

CONCLUSION: 3-D representation software offers a plausible alternative for 3-D representation of conventional capsule endoscopy images (until optics technology matures enough to allow hardware enabled-“real” 3-D reconstruction of the gastrointestinal tract).

The American Society for Gastrointestinal Endoscopy (ASGE) diagnostic algorithm for obscure gastrointestinal bleeding: eight burning questions from everyday clinical practice

The diagnosis and management of patients with obscure gastrointestinal bleeding are often long and challenging processes. Over the last 10 years the introduction in clinical practice of new diagnostic and therapeutic procedures (i.e. Capsule Endoscopy, Computed Tomographic Enterography, Magnetic Resonance Enterography, and Device Assisted Enteroscopy) has revolutionized the diagnostic/therapeutic work-up of these patients. Based on evidence published in the last 10 years, international scientific societies have proposed new practice guidelines for the management of obscure gastrointestinal bleeding, which include these techniques. However, although these algorithms (the most recent ones are endorsed by the American Society for Gastrointestinal Endoscopy - ASGE) allow the management of the large majority of patients, some issues still remain unsolved. The present paper reports the results of the discussion, based on the literature published up to September 2011, among a panel of experts and gastroenterologists, working with Capsule Endoscopy and with Device Assisted Enteroscopy, attending the 6th annual meeting of the Italian Club for Capsule Endoscopy and Enteroscopy. Eight unresolved issues were selected: each of them is presented as a "Burning question" and the "Answer" is the strategy proposed to manage it, according to both the available evidence and the discussion among participants.

Detection of the ampulla of Vater in small bowel capsule endoscopy: experience with two different systems

OBJECTIVE

The aim of this study was to determine the detection rate of the ampulla of Vater (AoV) during small bowel capsule endoscopy (SBCE) examinations and compare the two SBCE systems used in our center.

METHODS

SBCE procedures performed in our center from March 2005 to June 2011 were reviewed retrospectively. A single reviewer, following a detailed protocol, analyzed 30 min of each recording to identify the AoV.

RESULTS

A total of 619 SBCE procedures were enrolled in the study, including 262 with a PillCam SB1, 148 with a PillCam SB2 and 209 with a MiroCam. AoV was identified in 59 SBCE examinations (9.5%), consisting of 28 with a PillCam SB1 (28/262, 10.7%), 13 with a PillCam SB2 (13/148, 8.8%) and 18 with a MiroCam (18/209, 8.6%) (P = 0.665). The AoV was visualized in 53.2 frames (median 12 frames, range 1-1056 frames); and the detection rate was low regardless of indication, patients' characteristics, SBCE system used or capsule transit parameters. Bile spout was associated with a higher AoV detection (P = 0.003).

CONCLUSIONS

The persistently low AoV detection rate using two different SBCE systems underlines the weakness of non-steerable capsule endoscopy. Furthermore, if AoV detection is taken as a surrogate marker of small polyp detection, it becomes obvious both that non-steerable SBCE cannot replace a side-viewing endoscope in the evaluation of periampullary polyps in familial adenomatous polyposis and that it is an infallible method in other small bowel polyposis states.