Veterinary Endoscopy for the Small Animal Practitioner. Группа авторов
target="_blank" rel="nofollow" href="#ulink_2e29d1a1-7714-5990-8054-7574a499b933">Figure 2.31 A one‐piece cystoscope incorporating the telescope and sheath into one unit with a 9.5 Fr diameter, a working length of 14 cm, a 3 Fr instrument channel, and 2 fluid connection ports with 2 stopcocks. This telescope has a better image than the 1.9 mm diameter cystoscope and sheath that it replaces plus it is much more robust.
(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)
Figure 2.32 A 10 mm diameter, 0° operating laparoscope with a working length of 23 cm and with a 6 mm diameter working channel for use with 5 mm diameter minimally invasive surgery instruments.
(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)
Most of the telescopes that we use in small animal practice are adapted from already available human instruments. One of the exceptions to this is the Veterinary Otoscope that was specifically developed and produced for small animal application (Figure 2.33). This telescope is a one‐piece instrument for ear examination in the awake patient.
Figure 2.33 The Veterinary Otoscope for ear examination in awake patients with a tip diameter of 5 mm, an 8.5 cm length with a 5 Fr working channel, and a stopcock attachment allowing simultaneous irrigation and passing 5 Fr instruments for manipulations.
(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)
A recent significant advance in telescope technology is that most telescopes are now autoclavable. The autoclavable telescopes are labeled as autoclavable. This feature greatly facilitates instrument turnaround and practice efficiency.
2.2.10 Flexible Endoscopes
Flexible endoscopes are described by insertion tube diameter, working length, working channel diameter, tip deflection control, and video or fiberoptic image (Figure 2.34). For small animal practice, flexible endoscopes range in diameter from 2.8 to 9.7 mm, working lengths from 70 to 140 cm, two‐way and four‐way tip deflection control, 1–2.8 mm working channel diameter, and are available in fiberoptic and video options. Light transmission into the patient is through an incoherent fiberoptic bundle incorporated into the flexible endoscope insertion tube and flexible umbilical cord that connects to an external remote cold light source. Some flexible endoscopes use a flexible fiberoptic light guide cable as used with rigid telescopes to connect to the external light source. The advent of LED light sources has also made it possible to incorporate a light source into the endoscope (Figure 2.10).
Figure 2.34 The anatomy of a flexible fiberoptic gastrointestinal endoscope. A connector that attaches to a light source with an air pump for insufflation is at the proximal end of the umbilical cord. This connector has a light guidepost, an air insufflation tube, suction connector, lens washing water container connection, a pressure compensation valve, and electrical contacts. The umbilical cord runs from this connector to the handpiece of the endoscope carrying the light guide cable, suction channel, and air insufflation/water channel. The handpiece has an eyepiece section with fiberoptic endoscopes, angulation control knobs with breaking levers, a suction valve, an air insufflation/water valve, and an operating channel port. The eyepiece has a focus ring and camera attachment mechanism. Video endoscopes do not have the eyepiece section. The insertion tube is the portion of the endoscope extending from the handpiece to the distal tip that is passed into the patient. The tip portion of the endoscope is called the bending section and is the portion of the endoscope that is bent using the angulation control knobs on the handpiece. Additional information of flexible gastrointestinal endoscopes is presented in Chapter 3.
Addition of CCD and CMOS video chip technology to endoscopy has dramatically improved image quality beyond traditional fiberoptic images. Even though video endoscopes are more expensive, the increased image quality and elimination of deterioration in image quality of fiberoptic bundles over time make the added expense well worth the investment.
The most common flexible endoscopes used in small animal practice are the 2.8 mm diameter 70 cm, working length fiberoptic or video uretero‐cystoscope; the 6.2 mm diameter, 61 cm working length video bronchoscope; 5.2 mm diameter, 85 cm working length fiberoptic bronchoscope; and 7.9 or 9.7 mm diameter, 140 cm working length video gastroscopes (Table 2.4).
Table 2.4 Flexible endoscopes commonly used in small animal practice.
| Video gastroscopes9.7 mm sheath diameter, 140 cm working length, 4‐way tip control, 2.8 mm diameter working channel (Karl Storz #60914NKSK)7.9 mm sheath diameter, 140 cm working length, 4‐way tip control, 2.8 mm diameter working channel (Karl Storz #60714NKSK)Video bronchoscope (recommended to use feline video gastroscope)5.9 mm sheath diameter, 110 cm working length, 4‐way tip control, 2.0 mm diameter working channel (Karl Storz #60511NKSK)Fiberoptic bronchoscope5.2 mm sheath diameter, 85 cm working length, 2‐way tip control, 2.3 mm diameter working channel (Karl Storz #60001VLK2)3.7 mm sheath diameter, 65 cm working length, 2‐way tip control, 1.5 mm diameter working channel (Karl Storz #60002VBK2)Video uretero‐cystoscope8.5 Fr sheath diameter, working length 70 cm, 2‐way tip control, 3.6 Fr working channel (Karl Storz #60278VSK) |
2.2.11 Sheaths, Cannulas, and Trocars
Rigid telescopes are used with sheaths, cannulas, or trocars depending on the procedure being performed (Figures 2.35–2.40). A specific sheath is required for each specific telescope size, instrument size, and procedure being performed. Telescope trocar‐cannulas for abdominal or thoracic wall penetration come with a sharp obturator that is removed after the cannula is in place to allow placement of the telescope. Many of these cannulas also have a blunt obturator that is used when needed for replacing cannulas that have become displaced, for the Hassan technique of laparoscopy portal placement, and for paraxiphoid thoracic port placement. Sheaths for smaller telescopes are also used to protect the telescope from breakage and lock to