Biologic Tissue Sampling With Untethered Microgrippers

Abstract

Even with advances in non-invasive diagnosis of diseases such as cancer or inflammatory diseases, tissue biopsy coupled with histopathologic examination remains the gold standard in establishing an accurate diagnosis.1–2 Generally, effective tissue diagnosis is fundamentally based on biopsying lesions that are suspicious based on visual inspection. Nevertheless, numerous mucosal conditions, such as dysplasia in ulcerative colitis or Barrett’s esophagus, are not always readily recognizable visually, and thus mandate surveillance protocols that involve random biopsies.3 To effectively sample large organs such as the colon, numerous biopsies are required,4 which can be time consuming. Moreover, due to the size of current forceps and the associated mucosal trauma and to the serial operation of the forceps, the number of random biopsies that can be realistically carried out is limited. Consequently, the current standard of care for cancer surveillance in ulcerative colitis patients is performed with at least 33 sequential biopsies (4-quadrant biopsies every 10 cm), which we estimate cumulatively samples less than 0.3% of colonic mucosa. The low sampling coverage may be ineffective at detecting precancerous or cancerous lesions, especially for early, small lesions that are also the most treatable.