Endoscopy Around the World: Perspectives

The development of the swallowable video capsule (M2A)

Capsule endoscopy (CE) is useful in evaluating disease surveillance for primary small-bowel follicular lymphoma (FL), but some cases are difficult to evaluate objectively. This study evaluated the usefulness of a deep convolutional neural network (CNN) system using CE images for disease surveillance of primary small-bowel FL.

We enrolled 26 consecutive patients with primary small-bowel FL diagnosed between January 2011 and January 2021 who underwent CE before and after a watch-and-wait strategy or chemotherapy. Disease surveillance by the CNN system was evaluated by the percentage of FL-detected images among all CE images of the small-bowel mucosa.

Eighteen cases (69%) were managed with a watch-and-wait approach, and 8 cases (31%) were treated with chemotherapy. Among the 18 cases managed with the watch-and-wait approach, the outcome of lesion evaluation by the CNN system was almost the same in 13 cases (72%), aggravation in 4 (22%), and improvement in 1 (6%). Among the 8 cases treated with chemotherapy, the outcome of lesion evaluation by the CNN system was improvement in 5 cases (63%), almost the same in 2 (25%), and aggravation in 1 (12%). The physician and CNN system reported similar results regarding disease surveillance evaluation in 23 of 26 cases (88%), whereas a discrepancy between the 2 was found in the remaining 3 cases (12%), attributed to poor small-bowel cleansing level.

Disease surveillance evaluation of primary small-bowel FL using CE images by the developed CNN system was useful under the condition of excellent small-bowel cleansing level.

In this chapter, we provide a critical discussion on the fabrication challenges for endoluminal microdevices. We detail the physical laws that govern the miniaturization of a device, the theoretical mechanical limits of miniaturized structures, and the viability of different fabrication options depending on the application. Then, we provide fabrication examples based on the classification of endoluminal devices: rigid, articulated systems for minimally invasive surgery, flexible tethered systems for navigation and intervention inside tubular organs or cavities, and wireless systems for diagnosis and intervention inside hollow organs. The chapter will conclude with a discussion on main take-away lessons and future directions in the field.