Figure 1.13 A video gastroscope with a video camera chip at the tip of the endoscope with elimination of the image guide bundle and the eyepiece at the handle of the endoscope.
(Source: Photo courtesy of Karl Storz: ©Karl Storz SE & Co KG, Germany.)
Figure 1.14 An image of the duodenum in an 8‐year‐old neutered male 10 kg mixed breed dog with IBD illustrating the superior image produced with a video gastroscope.
Three‐dimensional video systems have been attempted for many years, but none have become popular or achieved a significant market presence. A recently released computer‐enhanced dual image system with significant improvement of image function may change this position for this technology.
Computer‐enhanced image technology has also entered the market with image manipulation to increase the visibility of normal and abnormal tissues. Photodynamic analysis systems are available that use fluorescing dyes combined with specific wavelength light sources, filters, and cameras facilitating the identification of tumors used to improve early diagnosis.
1.3 Clinical Application in Veterinary Medicine
Use of endoscopy in animals was listed in the early history of endoscopy in human medicine but it was not a clinical application and is not relevant to our history. At the time I graduated from Veterinary School in 1969, endoscopy was not a part of our clinical discussions. Endoscopy in small animal veterinary medicine first appeared in the early 1970s. Endoscopic evaluation of the lower respiratory tract in dogs and cats was first reported in 1970 (O'Brien 1970). The first use of laparoscopy for the evaluation of liver and pancreatic disease was reported in 1972 (Dalton and Hill 1972; Lettow 1972). The first reported use of gastrointestinal endoscopy in practice was in 1976 (Johnson et al. 1976). Gastrointestinal endoscopy developed widespread clinical application before any other techniques and has been the most frequently used endoscopic procedure in small animal medicine. Bronchoscopy also gained wide acceptance during this time period.
Other techniques were slow to develop but have recently expanded to become a major portion of small animal diagnostic and operative procedures. Arthroscopy of the shoulder and stifle joints was reported in the late 1970s and during the 1980s (Siemering 1978, Kivumbi and Bennett 1981; Person 1987; Person 1989) but was very slow to gain acceptance because of its difficulty and the long, steep, frustrating learning curve.
Cystoscopy in male and female dogs was first reported as a research technique in 1930 (Vermooten 1930) but did not appear in clinical use until the 1980s. A technique conceived from the concept of cystocentesis and adapted from human medicine was used in early 1983 for access to the bladder using a prepubic percutaneous approach (McCarthy and McDermaid 1986). This technique initiated endoscopic evaluation of the urinary tract in clinical practice. This publication also initiated identification and study of feline lower urinary tract disease as it relates to interstitial cystitis (Buffington 1994). As an accidental incident, while performing vaginoscopy with the 2.7 mm multipurpose rigid telescope (MPRT), the urethral orifice was identified followed by passage of the telescope through the urethra and into the bladder. From this, transurethral cystoscopy emerged as an easy and effective diagnostic procedure in the 1980s (Biewenga and van Ostrum 1985; Senior and Sundstrom 1988; McCarthy and McDermaid 1990; McCarthy 1996). Availability of small flexible urethroscopes made transurethral cystoscopy in male dogs and cats possible.
Invasion of other natural orifices continued to progress with rhinoscopy, otoscopy, and vaginoscopy being added to the list of procedures available. Invasion of body cavities expanded to include thoracoscopy. All these procedures started as diagnostic techniques allowing examination of the area of interest with ability to collect diagnostic samples.
Expansion of these procedures to include treatment allowing us to correct the pathology that we found provided strong incentive for continued growth of endoscopy in small animal practice. Introduction of minimally invasive surgery in human medicine in the 1980s exploded as the procedure of choice for many abdominal surgeries. This translated rapidly into small animal practice with veterinary involvement including design, development, and testing of instrumentation for minimally invasive surgery plus training human surgeons.
Laparoscopic ovariohysterectomies in small animals first performed as research procedures, identified the possibility of Minimally Invasive Surgery (MIS) in small animals, and was used for technique development. The list of MIS procedures performed in small animal practice has grown to include many of the surgical procedures traditionally done as open surgery. Interventional endoscopy, application of therapeutic corrective procedures with cystoscopy, was developed for correction of ectopic ureters, stone removal, and tumor removal. Laparoscopic‐assisted techniques have also promoted expansion of MIS by applying laparoscopy for access to visualize and exteriorize organs with the use of open surgical technique to perform the actual procedure. This approach allows a minimally invasive approach but without the need for special skills and instrumentation needed for a totally intra‐corporeal procedure. NOTES, natural orifice transluminal endoscopic surgery, is the newest addition to our armamentarium of minimally invasive approaches where surgery is performed with special flexible endoscopes through oral, vaginal, or rectal approaches with no skin incisions.
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