Читать книгу Gastrointestinal Pathology - Группа авторов - Страница 12

The flexible pinch biopsy forceps have been one of the most versatile of all instruments for tissue acquisition. These typically involve a flexible steel cable and lever device with two sharp‐edged cups, which can be opened and closed to acquire tissue (Figure 1.4).

Standard endoscopic sampling typically acquires tissue from the mucosa and occasionally a submucosal depth of the intestinal wall; however, large‐capacity forceps as well as multiple sampling including “bite on bite” allow sampling of the deeper layers. Pinch biopsy forceps come in multiple sizes from very small instruments such as a pediatric forceps, which can be passed through very small working channels. Recent development of very tiny forceps makes it possible to pass them through special endoscopes into the bile or pancreas duct and to pinch biopsy outside of the traditional gastrointestinal lumen (Figure 1.5).

Studies comparing jumbo forceps to standard forceps have generally not shown significant advantages of larger capacity forceps. A limitation of most forceps is the inability to sample tissue in the submucosa routinely. This is highlighted in studies looking for Barrett's esophagus after the surface epithelium has been ablated. Biopsy forceps can remove tissue with mechanical closure alone or with electrocautery (“hot biopsy”) although the use of hot biopsy has diminished significantly due to increased risks of complication and tissue damage in the biopsy specimen.

Figure 1.4 Endoscopic biopsy forceps in the open position. The needle‐like pin in the center holds the tissue in place so one to two samples can be obtained per pass.

Figure 1.5 Micro biopsy forceps <1 mm in diameter, which can be passed through specialized endoscopes into the bile duct, pancreas duct, or via 19‐gauge needles for extraluminal tissue sampling.

Source: Boston Scientific Corporation with permission.

Figure 1.6 Endoscopic snare for polypectomy. The wire loop is extended in the open position outside the plastic sheath. When closed, the wire loop is strangulated and resects the polyp tissue.

Figure 1.7 Endoscopic cytology brush. Note the abrasive brush extended beyond the protective plastic sheath.