Читать книгу Veterinary Endoscopy for the Small Animal Practitioner - Группа авторов - Страница 33

Rigid telescopes used for endoscopy are described by the diameter, length, and angle of view. For small animal endoscopy, telescopes range in diameter from 1.0 to 10.0 mm and in length from 6.5 to 31 cm (Figure 2.26). Angle of view refers to the angle that the center of the image seen through the telescope deviates from the long axis of the telescope and ranges from 0° or straight ahead to 120° (Figure 2.27). A new rigid telescope design, the “ENDOCAMELEON”, has a variable adjustable angle of view from 0 to 120° for a 10 mm diameter, 32 cm long laparoscope version (Figure 2.28) and from 15 to 90° for a 4.0 mm diameter, 18 cm long arthroscopy/ENT version. Telescopes in use today are designed with what is termed a Hopkins rod lens system (Figure 2.29) for image transmission that has dramatically improved quality over previous lens systems. Light transmission into the patient is through a fiberoptic bundle incorporated into the telescope with a light post for attaching a flexible fiberoptic light guide cable that leads to an external remote cold light source (Figure 1.9).

Figure 2.26 Telescopes available for use in small animal practice including from left to right: A 10 mm diameter, 31 cm long, 0° laparoscope; a 5 mm diameter, 29 cm long, 0° laparoscope; a 4.0 mm diameter, 30 cm long, 30° cystoscope; a 1.0 mm diameter, 20 cm long, 0° semirigid needle scope; the 2.7 mm diameter, 18 cm long, 30° multipurpose rigid telescope (MPRT); a 3 mm diameter, 14 cm long, 0° laparoscope; a 2.4 mm diameter, 10 cm long, 30° arthroscope; and a 1.9 mm diameter, 6.5 cm long, 30° arthroscope that is set above the line of telescopes. The degree angles of the telescopes listed are examples and many are available in one to multiple viewing angles.

(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)

Figure 2.27 A diagram showing the angle of view of rigid telescopes used in small animal practice. Zero and thirty degree angles are the most commonly used angles. Greater angles are occasionally used but increase the difficulty in orientation of the image.

Figure 2.28 The ENDOCAMELEON telescope for laparoscopy with variable angles of view. A 10 mm diameter laparoscope is shown that has a working length of 32 cm and a variable view angle of 0–120°. The tip of the telescope has a curved outer lens housing with an inner lens that rotates through the variable angle range shown in the upper insert. The lens position is adjusted with the black ring behind the light post shown in the lower insert. The angles of the angle of view are shown in the insert at the tip of the endoscope.

(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)

Figure 2.29 A diagram of the Hopkins rod lens system shown in the telescope at the bottom and a conventional lens system in the telescope at the top. Hopkins rod lenses are the standard design for telescopes in current use today having superior image compared to conventional lens telescopes.

The most common telescope used for small animal endoscopy is a 2.7 mm diameter, 18 cm long, 30° angle of view arthroscope (Figure 2.26 and Table 2.2). This is called the 2.7 mm multipurpose rigid telescope (MPRT) because of its wide range of applications including cystoscopy, rhinoscopy, otoscopy, laparoscopy, thoracoscopy, bronchoscopy, laceroscopy, fistuloscopy, vaginoscopy, oculoscopy, neoscopy, transabdominal nephroscopy, transabdominal cholecystodocoscopy, and also arthroscopy. This telescope is supplied with multiple sheaths (Figure 2.30 and Table 2.3) allowing expansion of its use to include all the above listed procedures. Additional commonly used telescopes include those listed previously plus a 9.5 Fr one‐piece cystoscope (Figure 2.31) and operating laparoscopes (Figure 2.32). The length and angle of view of these telescopes vary based on their intended use with each having advantages, disadvantages, and specific best applications. The original intended use may or may not apply to its application in small animal practice and actual use is based on the diameter, length, angle of view, and sheath selection that fit our patient's needs. Current uses of individual telescopes will be presented in the individual chapters.

Table 2.2 Rigid telescopes used for small animal endoscopy.

10 mm diameter, 31 cm long, 0° laparoscope(Karl Storz #26003AA)5 mm diameter, 29 cm long, 0° laparoscope(Karl Storz #62046AA)3 mm diameter, 14 cm long, 0° laparoscope(Karl Storz #7220AA)2.7 mm diameter, 18 cm long, 30° multipurposeRigid telescope (MPRT) (Karl Storz #64029BA)2.4 mm diameter, 10 cm long, 30° arthroscope(Karl Storz #64300BA)1.9 mm diameter, 6.5 cm long, 30° arthroscope(Karl Storz #28305BA)1.0 mm diameter, 20 cm long, 0° semirigidNeedle scope (Karl Storz #62512)

Figure 2.30 The 2.7 mm diameter, 18 cm long, 30° multipurpose rigid telescope (MPRT) that is the most widely used telescope in small animal practice with a selection of sheaths available for use with this telescope. From upper left to lower right: the 14.5 Fr, 15 cm working length operating/cystoscopy sheath with a 5 Fr working channel, and 2 Luer connectors with stopcocks; the arthroscopy sheath with 4.0 mm outside diameter, 13.5 cm working length, and 1 Luer connector with a stopcock; the 2.7 mm diameter telescope; the examination and protection sheath with 3.5 mm outside diameter, 17 cm working length, and 1 Luer connector with a stopcock; and a 3.9 mm laparoscopy trocar‐cannula with a working length of 5 cm and a silicone leaflet valve.

(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)

Table 2.3 The 2.7 mm MPRT with available sheath selection.

2.7 mm diameter, 18 cm long, 30° telescope (Karl Storz #64029BA) Cystoscopy/operating sheath (Karl Storz#67065CK)14.5 Fr, 15 cm working length, 5 Fr operating channel, with 2 fluid portsArthroscopy sheath (Karl Storz #64132S)4 mm diameter, 13.5 cm working length, with 1 fluid port Guard or examination sheath (Karl Storz #64018US)3.5 mm diameter, 17 cm working length, with 1 fluid portLaparoscopy trocar cannula (Karl Storz #62117GK)3.9 mm diameter, 5 cm long, with a silicone leaflet valveLaparoscopy endotip cannula (Karl Storz #30117MT)3.9 mm diameter, 5 cm long, with an automatic valve

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.