Performance of disposable endoscopic forceps according to the manufacturing techniques

Abstract

Background/aims: Recently, to lower the production costs and risk of infection, new disposable biopsy forceps made using simple manufacturing techniques have been introduced. However, the effects of the manufacturing techniques are unclear. The aim of this study was to evaluate which types of biopsy forceps could obtain good-quality specimens according to the manufacturing techniques.

Methods: By using an in vitro nitrile glove popping model, we compared the popping ability among eight different disposable biopsy forceps (one pair of biopsy forceps with cups made by a cutting method [cutting forceps], four pairs of biopsy forceps with cups made by a pressing method [pressing forceps], and three pairs of biopsy forceps with cups made using a injection molding method [molding forceps]). Using an in vivo swine model, we compared the penetration depth and quality of specimen among the biopsy forceps.

Results: In the in vitro model, the molding forceps provided a significantly higher popping rate than the other forceps (cutting forceps, 25.0%; pressing forceps, 17.5%; and molding forceps, 41.7%; p = 0.006). In the in vivo model, the cutting and pressing forceps did not provide larger specimens, deeper biopsy specimen, and higher specimen adequacy than those obtained using the molding forceps (p = 0.2631, p = 0.5875, and p = 0.2147, respectively). However, the molding forceps showed significantly more common crush artifact than the others (cutting forceps, 0%; pressing forceps, 5.0%; and molding forceps, 43.3%; p = 0.0007).

Conclusion: The molding forceps provided lower performance than the cutting and pressing forceps in terms of crush artifact.

Keywords: Biopsy; Disposable equipment; Endoscopy; Instruments.

Figure 1.

Characteristics of disposable biopsy forceps according to the manufacturing techniques. Cutting forceps, made using a precision lathe technique, are characterized by the smoothest surface and the best finishing. Pressing forceps, made of a thin metal board with a press molding technique, are characterized by higher productivity and lower production cost than cutting forceps. Molding forceps, made with an injection molding process, are characterized by the highest productivity and lowest production cost. However, it has a coarse surface and crude design. Red circles present the typical characteristic areas of each type.

Figure 2.

In vitro nitrile glove popping test. (A) The tip of air-filled nitrile glove, which are put on during endoscopic examination, is grasped and pulled with biopsy forceps to see if there is any popping. The popping occurs by two phenomena as follows: the cutting phenomenon, where only the part grasped inside the cups of the biopsy forceps is sharply cut (B), and the tearing phenomenon, where not only the part grasped inside the cups but also the surrounding areas are torn (C).

Figure 3.

Endoscopic examination with biopsy samplings. Five specimens were obtained from the greater curvature side of the antrum in one swine (A, B), and five specimens were obtained from the opposite lesser curvature side of the antrum in the other swine (C, D).

Figure 4.

Representative images of crush artifacts classified as grade 0 to 3 (H&E, × 200). (A) Grade 0, no crush artifact; (B) grade 1, mild crush artifact; (C, D) grade 2, moderate crush artifact; and grade 3, severe crush artifact that can affect diagnosis. The arrows present the compression areas that were used for classifying the degree of crush artifact, and red dot circles present the parts of tearing tissues.

Figure 5.

Comparison of specimen sizes according to manufacturing company. No significant difference was observed between the eight types of forceps (p = 0.5180) (A, cutting forceps, Olympus; B, pressing forceps, Boston Scientific; C, pressing forceps, Cook Medical; D, molding forceps, Upex-Med; E, molding forceps, Finemedix; F, pressing forceps, Medwork; G, pressing forceps, Incore; and H, molding forceps, Taewoong Medical).

Figure 6.

Comparison of specimen sizes according to manufacturing technique. No significant difference was observed between the three groups (p = 0.2631).