Endoscopy Practice and Safety
Peter B. Cotton
4. Endoscopic equipment
Gregory G. Ginsberg
Fig. 1 Flexible endoscopes are composed of three sections: the control section, the insertion tube, and the connector section. Particular
features of any given endoscope are modified to best accomplish the intended use. The instrument depicted here is a variable
stiffness colonoscope, equipped with a stiffness control apparatus.
Fig. 2 The insertion tube contains one or two instrument channel(s), one or two light guide bundles (incoherent fiber optic), an
air channel, a water channel, either an image guide bundle (coherent fiber optic) or a CCD chip with wire connections, and
angulation wires. The angulation wires deflect the bending section of the insertion tube. The contents are confined within
a mesh tube and covered with an outer polymer layer.
Fig. 3 The duodenoscope is a side-viewing (at 90° to the longitudinal access of the insertion tube) instrument designed primarily for ERCP. Duodenoscopes are equipped with
an elevator lever that allows deflection of devices passed through the endoscope accessory channel.
Fig. 4 A choledochoscope is a thin caliber endoscope that is passed through the instrument channel of a duodenoscope and inserted
intraductally for direct imaging of the (a) biliary and (b) pancreatic ducts.
Fig. 5 Radial scanning echoendoscopes have a sector scanning ultrasound transducer affixed to the tip of the endoscope providing
Fig. 6 The linear array format allows for longitudinal imaging acquired via linear-arrayed piezoelectric ultrasound transducers and
allows for ultrasound-guided fine-needle biopsy tissue sampling.
Fig. 7 (a) The capsule endoscope is a disposable plastic capsule which weighs 3.7 g and measures 11 mm in diameter × 26 mm in length. (b) The contents include a metal oxide silicon (CMOS) chip camera, a short focal length lens, four white
light-emitting diode (LED) illumination sources, two silver oxide batteries, and a UHF band radio telemetry transmitter.
Fig. 8 Endoscopic biopsy forceps consist of a flexible, metal-coil outer sheath that houses a steel cable connecting a two-piece
plastic handle to opposed metal biopsy cups.
Fig. 9 Polypectomy snares are used for resection of sessile and pedunculated epithelial lesions throughout the digestive tract. Polypectomy
snares consist of an attached or continuous wire loop housed within a flexible synthetic polymer sheath.
Fig. 10 The Roth net (US Endoscopy, Mentor, OH) enables secure retrieval of multiple specimens from the upper and lower digestive
Fig. 11 Injection needles consist of an outer sheath (plastic, Teflon, or stainless steel coil) and an inner hollow core needle.
Fig. 12 Spray catheters are disposable, flexible, hollow plastic sheaths, with a plastic luer lock handle and a metal spray nozzle
tip (a). Vital stains, like Lugol's iodine seen here, and contrast agents are applied via spray catheters.
Fig. 13 Contact hemostasis probes deliver thermal energy by completion of an electrical circuit between two or more electrodes on
a probe at the tip of a flexible shaft. Here the electrodes are arrayed in a spiral fashion.
Fig. 14 Cylindrical diffuser laser fibers are used in photodynamic therapy (PDT). (a) These flexible glass fibers are modified with a variable length tip that promotes uniform scattering of laser light energy
circumferentially along the long axis of the diffuser tip. (b) A further modification of the cylindrical diffusion catheter used for PDT in the esophagus incorporates an inflatable centering
Fig. 15 The argon plasma beam coagulator is a non-contact electrocoagulation device. Monopolar current is conducted to the target
tissue through an ionized argon gas (argon plasma).
Fig. 16 Variceal band ligation devices consist of a transparent, hollow-chamber, friction-fit adapter affixed to the tip of the endoscope,
preloaded elastic band(s), and a release mechanism. The target tissue is suctioned into the hollow chamber of the friction-fit
adapter. A trigger mechanism deploys an elastic band, ligating the target tissue.
Fig. 17 (a) The clip-fixing device consists of a control section and an insertion tube. The control section incorporates movable plastic
parts that manipulate clip loading and deployment. The insertion tube is made up of a metal coil sheath contained within an
outer plastic sheath. A metal cable moves within the coil sheath. (b) The clips themselves are configured of a multi-angled
stainless steel ribbon. When fully opened, the predeployment distance between the clip prongs measures 7 mm.
Fig. 18 (a) The detachable snare or 'endoloop' (Olympus HX-20Q, Olympus Corp., Tokyo). The nylon loop is non-conductive and consists of a heat-treated circular or elliptically
shaped nylon thread and a silicon-rubber stopper that maintains the tightness of the loop. (b) Following snare resection of
the large pedunculated polyp, a detachable loop was applied to prevent delayed bleeding.
Fig. 19 Plastic transparent caps that affix to and overhang the tip of the endoscope may be used to enhance colonic visualization
and to facilitate endoscopic mucosal resection.
Copyright © Blackwell Publishing, 2005