192 chapter 8 Principles of Endoscopy Branden Duffey, DO l Manoj Monga, MD, FACS Equipment Cystourethroscopy Upper Urinary Tract Endoscopy Patient Preparation T he purpose of this chapter is to introduce the basic principles of endoscopy as they relate to retrograde instrumentation and visualization of both the lower and the upper urinary tract. In addition to discussing strategies for both routine and dif- cult retrograde access, emphasis is placed on patient positionin g and preparation, basic equipment, and ancillary instrumentation required for both cystourethroscopy and ureteropyeloscopy. In-depth discussion of treatment strategies for specic pathologic processes is beyond the scope of this chapter and the reader is directed to specic chapters throughout this text. EQUIPMENT Retrograde visualization of the urinary tract is a routine part ofthe urologist’s practice and may be performed in a variety of set- tings. Straightforward procedures (i.e., cystoscopy with minimal intervention) may be performed in the ofce setting and requires only an endoscope, light source, and irrigating uid. The urologist views the procedure through the optical eyepiece at the proximal end of the instrument. Either xenon or halogen external light sources deliver cool light to the endoscope through a beroptic cable. Typical irrigation uids include sterile water, glycine, or normal saline. If electrocautery use is anticipated, a solution free of electrolytes should be used. Video-endoscopi c units, comprising a light source, camera for the endoscope, image processor and recorder, and monitor , are usually arranged on a mobile tower and commonly found in both the ofce and operating room settings (Fig. 8–1). Images are transmitted to the image processor by a camera attached to the eyepiece and displayed on a viewing monitor . In the case of digital endoscopes there is no eyepiece and the image is sent directly to the image processor. In both cases, still images and live sequences can be transferred to a recording device for incorporation into the medical record, postprocedure review, and patient education. Video-endoscopic units are advan- tageous in that they (1) avoid surgeon contact with bodily uids; (2) may facilitate more ergonomic surgeon positionin g during the procedure; (3) enhance the teaching of endourologic skills; and (4) may decrease discomfort in male patients during cystoscopy performed using local anesthesia (Patel et al, 2007). Light source modications, specically narrow band imaging and porphyrin- based uorescence, have been developed in efforts to improve the detection of urothelial carcinoma during endoscopy . Narrow band imaging technology lters white light into two separate bands (415 nm and 540 nm) that are absorbed by hemoglobin, which aids in the detection of hypervascular urothelial neoplasia (Herr and Donat, 2008). In uorescence-based endoscopy , a solution of5-aminolevulinic acid or hexaminolevulinate is instilled in the bladder and then inspected with blue light (wavelength 380 to 450 nm). These substances aid in tumor detection because they are converted to porphyrins that preferentially accumulate in neo- plastic cells and uoresce red when illuminated with blue light (Kriegmair et al, 1996). Urology-specic endoscopy suites are found in the operating room and generally have full video capa- bilities in addition to uoroscopy provided by either a mobile C-arm or endoscopy table. Fluoroscopy is used to perform retro- grade pyelography and ureteral stenting and to localize endo- scopes and instruments during the procedure. It is imperative that operating room personnel minimize radiation exposure by wearing leaded aprons, thyroid shields, and eyewear. CYSTOURETHROSCOPY Indications Cystourethroscopy is used to directly visualize the anterior urethra, posterior urethra, and the bladder. One of the most common indications for cystourethroscopy is the evaluation of microscopic and gross hematuria. Other indications for cystourethroscopy include evaluation of voiding symptoms, surveillance of urothelial carcinoma, foreign body removal, and assisting in difcult place- ment of a catheter. Although its primary use is in the diagnosis and treatment of lower urinary tract disorders, it is also used to access the upper urinary tract for both diagnostic and therapeutic interventions. Specic to the lower urinary tract, cystourethroscopy is an adjunctive procedure that permits macroscopic visualization that may be correlated with signs and symptoms of lower urinary tract pathologic processes. Additionally , uid and tissue specimens may be obtained for cytologic and histologic evaluation. The upper urinary tract may be accessed using cystoscopic tech- niques. Diagnosti c evaluation of the upper urinary tract is accom- plished by selective intubation of the ureteral orices and retrograde instillation of contrast material. Ureteral catheters and brushes can be passed into the upper urinary tract to obtain speci- mens for cytologic and histologic evaluation. In cases of upper tract obstruction, ureteral stents are often placed with cystoscopic assistance. Fluoroscopy is utilized in many, if not all, of these retrograde interventions.
