Fausto Brandão and Christopher Chamness
Key Points
Full HD (High Definition) is now the standard in veterinary video‐assisted surgery, which is defined as 1920 × 1080 pixels, currently provided with the latest generation CMOS chip cameras.
The “minimally invasive” concept has led to the introduction of miniature scopes and needlescopes into the field of small animal MIS with proven reduced morbidity.
Digital contrast technologies and tissue‐targeted dying technologies such as ICG (indocyanine green) fluorescence yield increased accuracy for refined and advanced minimally invasive procedures enabling higher detail visual perception of living tissues.
Integration platforms and converging MIS technologies enable the control of multimodal systems from a single screen for operator ease.
Imaging Equipment
While veterinary surgeons have defined and implemented the major trends and achievements in minimally invasive surgery (MIS) over the past 20 years, the development of specialized techniques and instrumentation made it possible for professionals to enhance the accuracy and complexity of the procedures. Over these two decades, many veterinary practices and hospitals implemented new standards of surgical care and realized the benefits associated with video‐assisted laparoscopic and thoracoscopic surgeries, utilizing those techniques on a regular basis, despite previous objections to high economic investment. The goal of this chapter is to update and familiarize practitioners with currently available technologies for a fully equipped and integrated MIS operating room (OR). Careful selection of the most versatile, durable, and integrable units is nowadays the gateway to the ongoing evolution of veterinary MIS.
Imaging Chain
The current standard surgical endoscopy imaging system consists of a light source, light‐transmitting cable, endoscope, camera head and camera control unit (CCU), and monitor (Figure 3.1). Each part is critical, and the resulting surgical image can only be as good as the weakest component in the chain. For example, if a surgeon has a full high‐definition (HD) camera, HOPKINS® telescope and light cable, but incorporates into the chain a standard‐resolution monitor, the resulting image quality will be limited by the quality of the screen. Even an old, damaged, or dirty light cable can degrade the image quality of an otherwise high‐end endoscopic imaging system [1–5]. An image troubleshooting guide is presented in Table 3.1.
Figure 3.1 The basic endoscopic imaging chain.
Source: © KARL STORZ SE & Co. KG, Germany.
The light generated by the light source is transmitted via optical fibers in the fiberoptic light cable and the telescope, to illuminate the anatomical space being observed. The image is transmitted through a series of lenses from the distal tip of the telescope to the eyepiece. Next, the chip in the video camera head senses the image and transmits it to the CCU, which processes the endoscopic image and transmits it to a monitor for viewing. This video projection enables the surgeon to maintain an ergonomic posture and to share this visual information with other participants. Furthermore, video imaging facilitates documentation of procedures, in several formats, valuable for medical records, teaching, client education, or consultation purposes [1–5]. Video imaging also enables remote access to view the procedure via live streaming through an integration platform [6].
Telescopes
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General Concepts
Rigid endoscopes are more convenient than flexible endoscopes for examining and performing procedures in body cavities [7–9]. Rigid scopes (i.e., telescopes) are also much simpler in design and less expensive than flexible endoscopes. Despite their lens system and fiber optics, they do not contain flexible materials, are easier to clean and maintain, and have a longer working lifespan [10]. Some models may include a working channel, integrated instrument, or a variable viewing angle, which allows a wider viewing field, in narrow deep anatomical regions. State‐of‐the‐art rigid telescopes are constructed with high‐quality optical glass rod lenses (HOPKINS® rod lenses), producing high‐quality images that are bright, magnified, wide angle, and of high resolution and contrast [1–5, 9]. No single model of rigid endoscope is universally suitable. The appropriately sized telescope should be selected based on the surgical procedure, size, and morphology of the patient and ultimately by the preference and experience of the surgeon. Although smaller scopes tend to be more versatile, they are also more prone to breakage, and their illumination capacity is limited when used in larger, more light‐absorptive cavities such as the abdomen or thorax of large breed dogs.
Table 3.1 Image troubleshooting guide.
| Problem | Possible cause | Resolution |
|---|---|---|
| Image is not clear | Fogged or dirty lens | Blot distal lens of telescope on live tissue or apply antifog agent to lens. |
| Fogged distal lens | Immerse telescope in warm sterile water or apply antifog agent to lens. | |
| Dirty eyepiece, camera, or adapter | Clean using cotton swab moistened with sterile water. | |
| Lens not adjusted to operator's eyesight | Rotate focus adjustment ring on camera head until image is clear. | |
| Internal fluid damage or cracked rod lens | Moisture within telescope will permanently cloud lens in distal end or eyepiece (repair by manufacturer). | |
| Misconnected camera on telescope eyepiece | Check for proper coupling and positioning of camera head to telescope by adjusting adapter. | |
| Image is too dark or too bright | Dirty light guide | Clean light‐guide connector and distal tip using gauze moistened with sterile water. |
| Improper light source or camera settings | Adjust brightness control knob, camera gain, or manual aperture setting. | |
| Old or improperly installed lamp | Properly install lamp; replace old lamp. | |
| Image is too blue | White balance improperly done or not done before telescope insertion into patient | Remove telescope from patient, clean distal lens, and perform white balance correctly. |
