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Cystoscopy: Techniques and clinical applications
Cystoscopy: Techniques and Clinical Applications Jeannette S. Messer, Dennis J. Chew, and Mary A. McLoughlin Cystoscopy is a powerful tool for characterization of lower urinary tract disease in dogs and cats. Current applications of cystoscopy include diagnostic and interventional techniques. This article reviews cystoscopy equipment, procedures, and common applications of cystoscopy. A review of normal anatomy and common lower urinary tract lesions identifiable with cystoscopy is also presented. Clin Tech Small Anim Pract 20:52-64 © 2005 Elsevier Inc. All rights reserved. KEYWORDS cystoscopy, uroendoscopy, bladder, urethra, ureters
C
ystoscopy, or uroendoscopy, is the use of optics and glass fibers to obtain images of the urethra, urinary bladder, and ureteral openings into the bladder. Cystoscopy allows rapid and definitive diagnosis of anatomic abnormalities of the lower urinary tract as well as bladder and urethral diseases. This technique is currently underutilized in veterinary medicine, but the decreased cost and increasing availability of equipment and training will likely make this technique more accessible in the future.
Cystoscopy Equipment A variety of cystoscopes are required for adequate evaluation of all patients (Table 1). Rigid cystoscopy instruments are used for female dogs and cats (Fig. 1) whereas flexible cystoscopes are needed for the smaller, curved urethras of male dogs and cats. Rigid cystoscopes are composed of three parts: the sheath that provides a smooth, rounded edge to protect both the mucosa and the telescope; the telescope which conducts light and the image; and the bridge that links the sheath and telescope and provides ports for installation of gas or liquid. Cystoscopes are available with a variety of viewing angles, but a 30-degree angle of view is most commonly utilized in veterinary cystoscopy. Image quality is significantly different from cystoscope to cystoscope with the best quality from large, rigid cystoscopes and lesser quality from small, flexible cystoscopes. Several manufacturers offer equipment suitable for cystoscopy in small animal patients (Table 2). Careful maintenance and storage of cystoscopy equipment
Small Animal Internal Medicine Section, The Ohio State University College of Veterinary Medicine, Department of Veterinary Clinical Sciences, Columbus, Ohio. Address reprint requests to Jeannette S. Messer, DVM, Resident, Small Animal Internal Medicine, Small Animal Internal Medicine Section, The Ohio State University College of Veterinary Medicine, Department of Veterinary Clinical Sciences, 601 Vernon L. Tharp St., Columbus, OH 43210. E-mail: [email protected]
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is essential. Cystoscopes should be gas or chemically sterilized according to the manufacturer’s directions and stored in protective cases. The operator assembles all parts of the cystoscope immediately before use. After assembly, the camera and light and fluid sources are connected to the cystoscope (Table 3). Several types of light sources are available, with the best being xenon light sources (Fig. 2). Images obtained by cystoscopy can be viewed directly through the cystoscope eyepiece or with a camera attached to the eyepiece. Cameras allow multiple observers to view the examination, provide magnification, and control light intensity (Fig. 3). Still and video images may be preserved and selected images used for the medical record. Some cystoscopes have instrument channels capable of accommodating biopsy instruments (Fig. 4), nets to retrieve stones, electrocautery, or lithotripsy instruments. A directed, consistent, systematic approach to cystoscopy is important for the best evaluation of the lower urinary tract. A standardized cystoscopy report will ensure that all portions of the lower urinary tract are evaluated (Figs. 5 and 6).
Cystoscopy Procedures We place patients in right lateral recumbency and the examiner sits behind or beside the patient in a comfortable chair with arm support. Others perform the examination with the patient in dorsal recumbency. The perivulvar or preputial area is clipped and aseptically prepared. The entire examination should be performed using sterile procedures, including sterile gloves for handling the equipment and the external genitalia. In male dogs, an assistant is required to extrude the penis from the prepuce (Fig. 7) and stay sutures or a mosquito hemostat on the prepuce may be necessary to extrude the feline penis from the prepuce (Fig. 8). A fluid source (0.9% saline) is attached to the cysto-
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Table 1 Cystoscopes Use
Type of Cystoscope
Large female dog (11-25 kg) Medium female dog (7-15 kg) Small female dog or female cat Male dog Male cat
Rigid Rigid Rigid Flexible Flexible
scope as well as a drain line (if desired). The light source and camera are also attached and the camera is white balanced and focused. The cystoscope is liberally coated with sterile lubricant and inserted into the vulva directed slightly dorsally in females or directly into the urethra in male dogs. In female dogs and cats, firm pressure and gentle traction on the vulva is used to create a chamber from the vaginal vestibule, which is then distended by fluid infusion (Fig. 9). Once the vagina, urethra, and cingulum have been visualized and the cystoscope oriented so that the vagina is at the top of the screen (dorsal), the examination may begin.
Normal Cystoscopic Anatomy The external genitalia should be examined for any evidence of discharge or anatomic abnormalities. In females, the vaginal vestibule, urethra, vagina, and cingulum should be examined for anatomic or mucosal abnormalities (Fig. 10). The cystoscope is then guided into the urethra while it is distended by fluid. The normal urethra is smooth and pale pink with a dorsal membrane. The dorsal urethral membrane may be used to orient the cystoscope so that the dorsal structures are at the top of the screen (Fig. 11). The urethra is the first structure encountered in males. It should be distended with fluid as the cystoscope is passed up the urethra. The view should be oriented to maintain the urethral lumen in the center of the screen. The distal urethra widens into the neck of the bladder. The bladder should be fully distended with fluid to examine the mucosa and external ureteral orifices. The collapsed or par-
Diameter 17-22 Fr 14 Fr 10 Fr 7.5 Fr 1.1 mm
Length 22-30 cm 16-18 cm 14-19 cm 55-100 cm 55 cm
tially distended bladder has many convoluted folds, which flatten out with distension. The bladder mucosa should be smooth and pale pink with a network of blood vessels crossing its surface.1 The trigone of the bladder is located immediately proximal and dorsal to the neck of the bladder. The two ureters are c-shaped mirror images of each other and are located in direct opposition in the same image plane. The right ureter is located on the right side of the image and the left ureter is on the left side of the image (Fig. 12). Once inside the bladder, the inflow and drainage ports of the cystoscope should be used to flush out urine and other debris to improve visualization. The bladder must be fully distended to definitively assess the position of the ureters within the bladder. Definitive identification of the ureters should involve observation of urine emanating from ureters. The remainder of the bladder should be evaluated in a systematic manner beginning with the apex. Visualization may be improved by moving the bladder around the cystoscope via abdominal palpation. Air bubbles will rise to the up side (left) of the bladder and urine can be seen pooling on the down side (right).2 Heavier material such as stones and crystals will fall to the gravity dependent (right) side of the bladder. The caudal reproductive tract should also be evaluated in females. The cystoscope may be passed into the urethra to an area just distal to the cervix called the pseudocervix.3 The canine vagina has a dorsal median postcervical fold that appears similar to the fold found in the urethra (Fig. 13).4
Clinical Applications of Cystoscopy Clinical Indications Abnormalities of micturition, abnormal urine composition, incontinence, recurrent urinary tract infections, urethral obstruction, and mass lesions identified with radiography or ultrasound are all indications for cystoscopy (Table 4). The caudal female reproductive tract may be evaluated using cystoscopy in dogs with difficulties during natural breeding, abnormal vulvar discharge, infertility, or
Table 2 Manufacturers of Equipment Used for Cystoscopy
Figure 1 Cystoscopy equipment. Rigid cystoscopes are used for females and male cats with perineal urethrostomies. It is important to match the size of cystoscope to the size of the patient. The best image will be obtained with the largest cystoscope that can be easily passed through the urethra.
Endoscopy Support Services, Brewster, NY Five Star Medical, Inc., Hayward, CA Karl Storz, Endoscopy America, Inc., Culver City, CA Mitsubishi, New York, NY Olympus, Melville, NY Stryker, San Jose, CA
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54 Table 3 Other Equipment Needed for Cystoscopy Light source Camera (optional) Video monitor (optional) Recording device (optional)
dystocia.5 Cystoscopy may be used to visualize lesions, obtain biopsies, resect masses, perform lithotripsy, as an adjunct to voiding hydropulsion, perform artificial insemination, and to deliver submucosal bulking agents to treat urinary incontinence.6
Limitations of Cystoscopy Cystoscopy requires general anesthesia for optimal urethral relaxation and patient restraint. It is most useful to evaluate the lower urinary tract and has limited use in lesions of the upper urinary tract. Biopsies can be obtained through the cystoscope; however, only small pieces of tissue are retrieved. Cystoscopy also requires specialized equipment and advanced training of both the operator and the assistant. Although the technique is not technically demanding, it does require education and experience to obtain good images and interpret the image findings. Cystoscopy performed in patients with recent (within 7 days) urinary tract surgery or in patients with urinary tract rupture can result in leakage of irrigation fluid into the abdomen.
Diagnostic Tests Used in Conjunction With Cystoscopy
Figure 3 Image capture. Images of the lower urinary tract may be viewed through the eyepiece of the cystoscope or via camera equipment attached to the cystoscope eyepiece. Still images or video images may be captured in a variety of formats depending on the equipment used.
Urodynamic studies (urethral pressure profiles and cystometrograms) are also used as adjuncts to cystoscopy to diagnose functional abnormalities of the lower urinary tract.
Variants of Normal
Cystoscopy is best used in conjunction with other diagnostic tests and not alone. Urinalysis should always be performed to identify abnormalities in the urine and urine culture to rule out urinary tract infection. Abdominal radiographs are helpful to characterize the size, shape, and location of the kidneys, ureters, bladder, and urethra. Radiopaque stones may also be identified. Contrast studies and abdominal ultrasound may be useful to identify abnormalities in ureter location, nonradiopaque stones, or mass lesions. Computed tomography is useful to diagnose subtle anatomic abnormalities such as ectopic ureters.7
It is important to be aware of normal variability of anatomy and imaging artifacts found in cystoscopy. The bitch in estrus will have a large flap of hyperplastic tissue covering the external urethral orifice that may be mistaken for a mass lesion (Fig. 14).3 Lipid droplets (Fig. 15) and air bubbles (Fig. 16) are commonly encountered and should not be mistaken for stones. Bands of tissue commonly referred to as frenulums, remnants of paramesonephric septae, or hymenal folds may be seen crossing the vaginal opening (Fig. 17).3 Their only clinical significance appears to be impairment of breeding; however, wide bands are often seen in patients with ectopic ureters (Fig. 18). In some dogs, there appears to be a fibrous band of tissue
Figure 2 Light sources. Many different light sources are available for use in cystoscopy. Xenon light sources are generally considered optimal and are available from several different companies. Some newer light sources have automatic light adjustment, but most require that an assistant adjust the light level throughout the examination.
Figure 4 Biopsy instruments. Most cystoscopes have an instrument channel that will accommodate a biopsy instrument. The cystoscope can be used to select an optimal location for biopsy and to direct the biopsy instrument.
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Figure 5 Female cystoscopy report. It is important to have a consistent and systematic procedure for the cystoscopic examination. Having a standardized cystoscopy report form can ensure that all anatomic structures are evaluated and all abnormalities are recorded.
encircling the vagina (Fig. 19). This band of tissue is seen in both normal dogs and dogs with signs of lower urinary tract disease.
Cystoscopic Lesions Lesions commonly identified with cystoscopy include bladder and urethral stones (Figs. 20 and 21), neoplasia in the bladder or urethra (Figs. 22 and 23), cystitis (Fig. 24), and anatomic abnormalities such as ectopic ureters (Fig. 25).8 Renal hematuria (Fig. 26), urethral strictures (Fig. 27), foreign material (Fig. 28), proliferative urethritis (Fig. 29), inflammatory bladder masses (Figs. 30 and 31) (ie, polyploid
cystitis), mucosal abscessation (Fig. 32) and ureteroceles may also be identified with cystoscopy.9-12
Advanced Diagnostic Techniques and Interventions Biopsy Some cystoscopes have instrument channels capable of fitting biopsy instruments. This allows the examiner to obtain tissue samples of any lesions identified cystoscopically. The drawback is that only very small pieces of tissue can be obtained in this manner. Biopsies may also be obtained through
J.S. Messer, D.J. Chew and M.A. McLoughlin
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Figure 6 Male cystoscopy report.
blind or ultrasound-guided traumatic catheterization after completion of the cystoscopy procedure.
erinary medicine.16 This type of therapy is most often palliative, but may be useful in cases of nonoperable bladder tumors or with pedunculated polyps.
Voiding Hydropulsion Cystoscopy may be used to identify bladder calculi and evaluate them for suitability for hydropulsion. Passing the cystoscope through the urethra may also improve dilation and lubrication of the urethra for stone passage. Finally, the cystoscope may be used to ensure that all stones have been evacuated from the bladder; this is especially helpful in patients with many small stones.
Ureteral Catheterization Some ureters are dilated to the extent that a cystoscope can be passed up the ureter. Once the cystoscope is in the ureter, urine samples may be sterilely obtained by attaching a syringe to the instrument channel. A technique for cystoscopeguided catheterization of the ureters has also been described in dogs.17,18
Dilation of Urethral Strictures Traumatic urinary catheterization, previous surgery, or stones lodged in the urethra may lead to urethral stricture. Proximal strictures may potentially be dilated by passing balloon catheters into the stricture and inflating the balloon. Cystoscopy aids in identification of strictures and characterization of their location and severity. The area should also be examined after dilation via cystoscopy.
Lithotripsy Cystoscopy guided lithotripsy probes may be used to break up bladder stones that are too large for hydropulsion. Techniques using electrohydraulic and laser lithotriptors have been described in dogs.13-15
Polyp or Mass Resection Electrocautery and cystoscopy-guided laser therapy to remove polyps and bladder masses have been reported in vet-
Submucosal Injections Submucosal bulking agents may be injected into the urethra to narrow the urethral lumen. Teflon, glutaraldehyde cross-linked collagen, and A-cell have all been used as submucosal bulking agents to treat urinary sphincter mechanism incompetence and decrease clinical urinary incontinence.19,20 The proximal urethra is visualized through the cystoscope and a needle is passed through the instrument port. Collagen or other material is loaded into the needle and the needle is inserted submucosally. Collagen is injected until a visible bleb of mucosa protrudes across at least 50% of the urethral lumen (Fig. 33). The blebs are placed in a clover pattern until 3 blebs have been placed and the lumen is completely occluded (Fig. 34). The bladder is expressed to verify that urine can pass through the collagen site and the patient is hospitalized until they urinate on their own.
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Figure 6 (Continued)
Potential Complications and Troubleshooting Cystoscopy Inability to Enter the Urethra Inability to enter the urethra is the most common complication of cystoscopy. Patient versus cystoscope size is the most important factor determining whether or not the cystoscope can be passed into the urethra and is the reason that several different sizes of cystoscopes are needed for successful procedures on a variety of patients. It is also important to remember that the viewing angle on the cystoscope is 30°. Two other reasons for failure to enter the urethra are direction of the cystoscope ventrally into the clitoral fossa (Figs. 35 and 36) or dorsally and cranially into the vagina that contains a dorsal ridge similar to that of the urethra.
Figure 7 Male dog cystoscopy procedures. In the male dog, the penis is extruded from the prepuce by an assistant while the examiner passes the cystoscope up the urethra. Fluid is injected through the instrument port to distend the urethra and ease the passage of the cystoscope. The instrument is manipulated to keep the image of the urethral lumen in the center of the screen.
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Figure 8 Male cat cystoscopy procedures. Just as in the male dog, the male cat penis is extruded from the prepuce and the flexible cystoscope is directed up the urethra while fluid is simultaneously infused to distend the urethra and ease the passage of the cystoscope. A mosquito hemostat or stay sutures secured to the prepuce may be necessary to maintain extrusion of the penis throughout the examination.
Poor Image Quality Poor image quality may be the result of imaging or patient factors. The image quality may be affected by the level of illumination, camera focus or lubricant obscuring the view. Patient factors include the degree of bladder distension, bladder hemorrhage (especially with distension), failure to distend the vaginal vestibule with fluid, or large amounts of debris in the urine. The bladder must be fully distended, but not so much that bladder hemorrhage occurs. The risk of hemorrhage can be minimized by periodically having an assistant pal-
J.S. Messer, D.J. Chew and M.A. McLoughlin
Figure 10 Vaginal vestibule. The appearance of the normal vaginal vestibule when distended with fluid. The vagina is located at the top of the screen, the cingulum is the band of tissue between the vagina and the urethra and the external urethral orifice is the opening in the middle of the image.
pate the bladder for size and drain fluid out of the bladder when it becomes too large. Bladder hemorrhage can be decreased by infusing chilled saline into the bladder and flushing the bladder. The use of cooled fluids requires close attention to patient body temperature since they can become hypothermic quickly; this is particularly a problem in small patients. It is important to select the largest cystoscope that can be easily and atraumatically passed into the urethra. Distending the vaginal vestibule with fluid in females improves the ability to visualize and enter the external urethral orifice. The male urethra should also be distended with fluid as the cystoscope is passed up its length. When debris in the urine compromises image quality, flushing the bladder with fluid can dramatically improve visualization.
Urinary Tract Infection Urinary tract infection can be a complication of cystoscopic procedures. It is uncommon when strict sterile pro-
Figure 9 Female cystoscopy procedures. The cystoscope is directed slightly dorsally to enter the vaginal vestibule. The vulvar labia are pressed firmly closed and retracted slightly to form a chamber that is distended with irrigation fluid.
Figure 11 Urethra. The normal female urethra is characterized by smooth, pale pink mucosa and a dorsal urethral membrane. The male urethra appears similar, but the urethral lumen is smaller and less distensible.
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59 Table 4 Indications for Cystoscopy
Figure 12 Normal location of the ureters within the bladder. The ureters are located just inside the bladder neck in the trigone. They are c-shaped and the open areas of the c’s face each other; both ureters are located in the same plane within the bladder. The right ureter is located on the right side of the screen and the left ureter on the left side of the screen.
cedures are followed to minimize contamination of the lower urinary tract. The large volumes of fluid used to flush the bladder and urethra are also helpful to minimize bacterial contamination. Routine use of a broad-spectrum antibiotic (amoxicillin) for 5 to 7 days postprocedure is recommended.
Damage to the Lower Urinary Tract Damage to the lower urinary tract as a result of cystoscopy is rare; however, perforation of the urethra (Fig. 37), bladder rupture, or lodging of the cystoscope in the urethra is possible.21 Proper technique and selection of equipment appropriate to the patient are the best way to minimize the risk of damage to the lower urinary tract. The
Disorders of micturition Pollakiuria Stranguria Incontinence Abnormalities of the urine stream Abnormalities of urine composition Hematuria Calculi Abnormal cells in the urine sediment Chronic or recurrent urinary tract infections Investigate anatomy Obtain urine from bladder or ureters for analysis and culture Identify mass lesions or calculi predisposing to infection Evaluation for evidence of cystitis or mucosal abscessation Trauma to the lower urinary tract Bladder rupture Avulsed ureters Urethral perforation Urethral obstruction Verify obstruction Relieve obstruction Verify resolution of obstruction Obtain samples of calculi, plugs, or masses causing urethral obstruction Urethral stricture Mass lesions identified using ultrasound or contrast radiography Verification of the lesion Characterization of the extent of the lesion Biopsy of lesion Anatomic abnormalities identified using ultrasound or contrast radiography Vaginal septa Ectopic ureters Urachal diverticula Adjunct to urodynamic studies Investigate presence of anatomic abnormalities or mass lesions that may influence results of urethral pressure profilometry or cystometrography Evaluation of the distal reproductive tract in females Stage of estrus cycle Evidence of vaginitis Interventions Lithotripsy Removal of pedunculated masses or polyps Implantation of submucosal bulking agents to treat incontinence
cystoscope should never be advanced with more than gentle pressure.
Conclusions Figure 13 Normal vagina. The caudal female reproductive tract can be examined via cystoscope from the vagina to an area just caudal to the cervix called the pseudocervix. The vagina has numerous mucosal folds and with distension, a dorsal membrane similar to that seen in the urethra, may be appreciated. The appearance of the mucosa changes during the estrus cycle.
Cystoscopy can be an invaluable adjunct to routine diagnostic procedures of the lower urinary tract in dogs and cats. It allows direct visualization of the areas of interest, enables biopsies of mass lesions and provides opportunities for intervention such as lithotripsy and submucosal collagen injections. Specialized equipment and advanced training are required for optimal cystoscopy results.
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Figure 14 Bitch in estrus. The mucosal folds of the vagina change in appearance with the stage of the estrus cycle. During estrus, there is often a large, hyperplastic fold of mucosa covering the external urethral orifice.
Figure 15 Lipid droplets. Lipid droplets are a normal component of feline urine and should not be mistaken for stones in the urinary bladder. The droplets should be found on the up-side of the bladder.
Figure 16 Air bubbles. Air bubbles are frequently introduced during cystoscopy. Bubbles are found on the up-side of the bladder and may aid in orientation during the examination.
J.S. Messer, D.J. Chew and M.A. McLoughlin
Figure 17 Vaginal vestibule with thin frenulum. Small bands of tissue, frenulums or hymenal remnants, are frequently found crossing the vagina. Unless the tissue distorts the anatomy of the urethra, it is of no clinical significance.
Figure 18 Vaginal vestibule with wide frenulum. Wide bands of tissue crossing the vagina are frequently found in patients with ectopic ureters. The opening to an ectopic ureter can be seen dorsal to the urethra just inside the external urethral orifice.
Figure 19 Vaginal vestibule with cingulum. The cingulum is the band of tissue between the vagina and urethra. Fibrous rings are frequently found encircling the vagina in normal dogs and dogs with clinical signs of lower urinary tract disease.
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Figure 20 Bladder stones in a dog. Bladder calculi are found in various shapes and sizes; these are calcium oxalate stones in a dog. Cystoscopy can be used to aid in hypdropulsion of small stones, to collect stones for quantitative analysis, or to perform intracorporeal lithotripsy and break stones into pieces small enough to remove via hydropulsion.
Figure 21 Bladder stones in a cat. These are calcium oxalate stones found in the bladder of a female cat. Voiding hydropulsion was used to remove the stones from the bladder. The gross appearance of stones is suggestive, but not diagnostic for their mineral content. Quantitative mineral analysis should always be used to identify the stone type and guide therapy.
Figure 22 Transitional cell carcinoma in a dog urethra. This image is from the urethra of a dog that had transitional cell carcinoma in both the urethra and urinary bladder. The cystoscope is an excellent tool to identify disease in the urethra and obtain biopsies of lesions.
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Figure 23 Transitional cell carcinoma in a dog bladder. Transitional cell carcinoma found in the bladder of a female dog. Cystoscopy can be used to biopsy masses identified using ultrasound or contrast radiographs. The magnification associated with cystoscopy images often allows identification of lesions within the urethra that are too small to identify with other imaging modalities. Bladder masses are frequently associated with extension of neoplastic tissue into the urethra.
Figure 24 Cystitis. This image was taken of a bladder from a female cat with signs of lower urinary tract disease and a negative urine culture. The prominent vascularity and glomerulations (submucosal petechial hemorrhages) seen here are characteristic of cystitis.22 Cystitis is also associated with increased mucosal friability and mucosal ulceration with subsequent hemorrhage frequently occurs with urethral and bladder distension. Lesions consistent with cystitis may be seen with feline lower urinary tract disease, bladder infection or sterile canine cystitis.
Figure 25 Ectopic ureters. Ectopic ureter in a female dog terminating in the proximal urethra.
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Figure 26 Renal hematuria. Cystoscopy may be used to identify the source of renal hematuria and to catheterize the ureters to obtain urine samples.
J.S. Messer, D.J. Chew and M.A. McLoughlin
Figure 29 Proliferative urethritis. Proliferative urethritis in a female dog; notice the proliferative tissue covering the external urethral orifice.
Figure 30 Benign inflammatory bladder mass. Many different types of benign and malignant masses can be visualized and biopsied via cystoscopy. This mass was composed of inflammatory tissue that formed along the suture line from a previous cystotomy. Some masses will take on the appearance of polyps within the bladder (polyploid cystitis). Figure 27 Urethral stricture. Stricture of the urethra in a male cat associated with perineal urethrostomy surgery.
Figure 28 Foreign material. Foreign material left in the urethra postintraurethral ureterectomy surgery for an ectopic ureter. Suture material can act as a nidus for recurrent urinary tract infection.
Figure 31 Benign inflammatory bladder mass. This mass consisted of inflammatory tissue that formed at the opening to the right ureter.
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Figure 32 Bladder wall abscessation. Images of the bladder wall from a dog with recurrent urinary tract infections. The bladder has markedly increased vascularity and 2 abscesses can be appreciated in the mucosa.
Figure 33 Collagen implantation. This image shows submucosal collagen injection in the urethra of a female dog. A needle is loaded with collagen and passed through the instrument port of the cystoscope. One operator directs the cystoscope while the other inserts the needle under the mucosa and injects collagen.
Figure 34 Collagen implantation. Ideal collagen placement results in complete occlusion of the urethral lumen. The bladder is expressed following the procedure to ensure that urination can occur, and patients are hospitalized until they urinate on their own.
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Figure 35 Appearance of the clitoral fossa. The clitoral fossa is a blind pocket of tissue located ventral to the vaginal vestibule.
Figure 36 Mucosal folds in the clitoral fossa. The clitoral fossa contains mucosal folds that may mimic the collapsed mucosa of the vaginal vestibule.
Figure 37 Partial urethral perforation. Complications associated with cystoscopy are rare. However, partial or complete perforation of the lower urinary tract can occur. The image shown here is iatrogenic partial perforation of the urethra of a female dog following a cystoscopy procedure. Proper equipment size and technique will decrease the risk of trauma to the urinary tract.
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References 1. Brearley MJ, Cooper JE: The diagnosis of bladder disease in dogs by cystoscopy. J Small Anim Pract 28:75-85, 1987 2. Chew DJ, Buffington T, Kendall MS, et al: Urethroscopy, cystoscopy, and biopsy of the feline lower urinary tract. Vet Clin North Am Small Anim Pract 26:441-462, 1996 3. Lindsay FEF: The normal endoscopic appearance of the caudal reproductive tract of the cyclic and non-cyclic bitch: Post-uterine endoscopy. J Small Anim Pract 24:1-15, 1983 4. Pineda MH, Kainer RA, Faulkner LC: Dorsal median postcervical fold in the canine vagina. Am J Vet Res 34:1487-1491, 1973 5. Root MV, Johnston SD, Johnston GR: Vaginal septa in dogs: 15 cases (1983-1992). J Am Vet Med Assoc 206:56-58, 1995 6. McCarthy TC. Cystoscopy, in McCarthy TC (ed): Veterinary Endoscopy for the Small Animal Practitioner. St. Louis, Elsevier; 2005, pp 49-135 7. Samii VF, McLoughlin MA, Mattoon JS, et al: Digital fluoroscopic excretory urography, digital fluoroscopic urethrography, helical computed tomography, and cystoscopy in 24 dogs with suspected ureteral ectopia. J Vet Intern Med 18:271-281, 2004 8. Cannizzo KL, McLoughlin MA, Mattoon JS, et al: Evaluation of transurethral cystoscopy and excretory urography for diagnosis of ectopic ureters in female dogs: 25 cases (1992-2000). J Am Vet Med Assoc 223:475-481, 2003 9. Moroff SD, Brown BA, Matthiesen DT, et al: Infiltrative urethral disease in female dogs: 41 cases (1980-1987). J Am Vet Med Assoc 199:247251, 1991 10. Hostutler RA, Chew DJ, Eaton KA, et al: Cystoscopic appearance of
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proliferative urethritis in 2 dogs before and after treatment. J Vet Intern Med 18:113-116, 2004 Eddlestone S, Taboada J, Senior D, et al: Renal haemangioma in a dog. J Small Anim Pract 40:132-135, 1999 Martinez I, Mattoon JS, Eaton KA, et al: Polypoid cystitis in 17 dogs (1978-2001). J Vet Intern Med 17:499-509, 2003 Senior DF: Electrohydraulic shock-wave lithotripsy in experimental canine struvite bladder stone disease. Vet Surg 13:143-148, 1984 Davidson EB, Ritchey JW, Higbee RD, et al: Laser lithotripsy for treatment of canine uroliths. Vet Surg 33:56-61, 2004 Wynn VM, Davidson EB, Higbee RG, et al: In vitro effects of pulsed holmium laser energy on canine uroliths and porcine cadaveric urethra. Lasers Surg Med 33:243-246, 2003 McCarthy TC: Transitional cell carcinoma. Vet Med 98:96, 2003 Ensor RD, Boyarsky S, Glenn FJ: Cystoscopy and ureteral catheterization in the dog. J Am Vet Med Assoc 149:1067-1072, 1966 Senior DF, Newman RC: Retrograde ureteral catheterization in female dogs. J Am Anim Hosp Assoc 22:831-834, 1986 Arnold S, Hubler M, Lott-Stolz G, et al: Treatment of urinary incontinence in bitches by endoscopic injection of glutaraldehyde cross-linked collagen. J Small Anim Pract 37:163-168, 1996 Arnold S, Jager P, DiBartola SP, et al: Treatment of urinary incontinence in dogs by endoscopic injection of Teflon. J Am Vet Med Assoc 195: 1369-1374, 1989 McCarthy TC: Cystoscopy and biopsy of the feline lower urinary tract. Vet Clin North Am Small Anim Pract 26:463-482, 1996 Osborn SD, Buffington CA, Chew DJ, et al: Cystoscopic identification of glomerulations in cats with idiopathic cystitis. J Vet Intern Med 1994:169 (abstr)
C
ystoscopy, or uroendoscopy, is the use of optics and glass fibers to obtain images of the urethra, urinary bladder, and ureteral openings into the bladder. Cystoscopy allows rapid and definitive diagnosis of anatomic abnormalities of the lower urinary tract as well as bladder and urethral diseases. This technique is currently underutilized in veterinary medicine, but the decreased cost and increasing availability of equipment and training will likely make this technique more accessible in the future.
Cystoscopy Equipment A variety of cystoscopes are required for adequate evaluation of all patients (Table 1). Rigid cystoscopy instruments are used for female dogs and cats (Fig. 1) whereas flexible cystoscopes are needed for the smaller, curved urethras of male dogs and cats. Rigid cystoscopes are composed of three parts: the sheath that provides a smooth, rounded edge to protect both the mucosa and the telescope; the telescope which conducts light and the image; and the bridge that links the sheath and telescope and provides ports for installation of gas or liquid. Cystoscopes are available with a variety of viewing angles, but a 30-degree angle of view is most commonly utilized in veterinary cystoscopy. Image quality is significantly different from cystoscope to cystoscope with the best quality from large, rigid cystoscopes and lesser quality from small, flexible cystoscopes. Several manufacturers offer equipment suitable for cystoscopy in small animal patients (Table 2). Careful maintenance and storage of cystoscopy equipment
Small Animal Internal Medicine Section, The Ohio State University College of Veterinary Medicine, Department of Veterinary Clinical Sciences, Columbus, Ohio. Address reprint requests to Jeannette S. Messer, DVM, Resident, Small Animal Internal Medicine, Small Animal Internal Medicine Section, The Ohio State University College of Veterinary Medicine, Department of Veterinary Clinical Sciences, 601 Vernon L. Tharp St., Columbus, OH 43210. E-mail: [email protected]
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1096-2867/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.ctsap.2004.12.008
is essential. Cystoscopes should be gas or chemically sterilized according to the manufacturer’s directions and stored in protective cases. The operator assembles all parts of the cystoscope immediately before use. After assembly, the camera and light and fluid sources are connected to the cystoscope (Table 3). Several types of light sources are available, with the best being xenon light sources (Fig. 2). Images obtained by cystoscopy can be viewed directly through the cystoscope eyepiece or with a camera attached to the eyepiece. Cameras allow multiple observers to view the examination, provide magnification, and control light intensity (Fig. 3). Still and video images may be preserved and selected images used for the medical record. Some cystoscopes have instrument channels capable of accommodating biopsy instruments (Fig. 4), nets to retrieve stones, electrocautery, or lithotripsy instruments. A directed, consistent, systematic approach to cystoscopy is important for the best evaluation of the lower urinary tract. A standardized cystoscopy report will ensure that all portions of the lower urinary tract are evaluated (Figs. 5 and 6).
Cystoscopy Procedures We place patients in right lateral recumbency and the examiner sits behind or beside the patient in a comfortable chair with arm support. Others perform the examination with the patient in dorsal recumbency. The perivulvar or preputial area is clipped and aseptically prepared. The entire examination should be performed using sterile procedures, including sterile gloves for handling the equipment and the external genitalia. In male dogs, an assistant is required to extrude the penis from the prepuce (Fig. 7) and stay sutures or a mosquito hemostat on the prepuce may be necessary to extrude the feline penis from the prepuce (Fig. 8). A fluid source (0.9% saline) is attached to the cysto-
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Table 1 Cystoscopes Use
Type of Cystoscope
Large female dog (11-25 kg) Medium female dog (7-15 kg) Small female dog or female cat Male dog Male cat
Rigid Rigid Rigid Flexible Flexible
scope as well as a drain line (if desired). The light source and camera are also attached and the camera is white balanced and focused. The cystoscope is liberally coated with sterile lubricant and inserted into the vulva directed slightly dorsally in females or directly into the urethra in male dogs. In female dogs and cats, firm pressure and gentle traction on the vulva is used to create a chamber from the vaginal vestibule, which is then distended by fluid infusion (Fig. 9). Once the vagina, urethra, and cingulum have been visualized and the cystoscope oriented so that the vagina is at the top of the screen (dorsal), the examination may begin.
Normal Cystoscopic Anatomy The external genitalia should be examined for any evidence of discharge or anatomic abnormalities. In females, the vaginal vestibule, urethra, vagina, and cingulum should be examined for anatomic or mucosal abnormalities (Fig. 10). The cystoscope is then guided into the urethra while it is distended by fluid. The normal urethra is smooth and pale pink with a dorsal membrane. The dorsal urethral membrane may be used to orient the cystoscope so that the dorsal structures are at the top of the screen (Fig. 11). The urethra is the first structure encountered in males. It should be distended with fluid as the cystoscope is passed up the urethra. The view should be oriented to maintain the urethral lumen in the center of the screen. The distal urethra widens into the neck of the bladder. The bladder should be fully distended with fluid to examine the mucosa and external ureteral orifices. The collapsed or par-
Diameter 17-22 Fr 14 Fr 10 Fr 7.5 Fr 1.1 mm
Length 22-30 cm 16-18 cm 14-19 cm 55-100 cm 55 cm
tially distended bladder has many convoluted folds, which flatten out with distension. The bladder mucosa should be smooth and pale pink with a network of blood vessels crossing its surface.1 The trigone of the bladder is located immediately proximal and dorsal to the neck of the bladder. The two ureters are c-shaped mirror images of each other and are located in direct opposition in the same image plane. The right ureter is located on the right side of the image and the left ureter is on the left side of the image (Fig. 12). Once inside the bladder, the inflow and drainage ports of the cystoscope should be used to flush out urine and other debris to improve visualization. The bladder must be fully distended to definitively assess the position of the ureters within the bladder. Definitive identification of the ureters should involve observation of urine emanating from ureters. The remainder of the bladder should be evaluated in a systematic manner beginning with the apex. Visualization may be improved by moving the bladder around the cystoscope via abdominal palpation. Air bubbles will rise to the up side (left) of the bladder and urine can be seen pooling on the down side (right).2 Heavier material such as stones and crystals will fall to the gravity dependent (right) side of the bladder. The caudal reproductive tract should also be evaluated in females. The cystoscope may be passed into the urethra to an area just distal to the cervix called the pseudocervix.3 The canine vagina has a dorsal median postcervical fold that appears similar to the fold found in the urethra (Fig. 13).4
Clinical Applications of Cystoscopy Clinical Indications Abnormalities of micturition, abnormal urine composition, incontinence, recurrent urinary tract infections, urethral obstruction, and mass lesions identified with radiography or ultrasound are all indications for cystoscopy (Table 4). The caudal female reproductive tract may be evaluated using cystoscopy in dogs with difficulties during natural breeding, abnormal vulvar discharge, infertility, or
Table 2 Manufacturers of Equipment Used for Cystoscopy
Figure 1 Cystoscopy equipment. Rigid cystoscopes are used for females and male cats with perineal urethrostomies. It is important to match the size of cystoscope to the size of the patient. The best image will be obtained with the largest cystoscope that can be easily passed through the urethra.
Endoscopy Support Services, Brewster, NY Five Star Medical, Inc., Hayward, CA Karl Storz, Endoscopy America, Inc., Culver City, CA Mitsubishi, New York, NY Olympus, Melville, NY Stryker, San Jose, CA
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54 Table 3 Other Equipment Needed for Cystoscopy Light source Camera (optional) Video monitor (optional) Recording device (optional)
dystocia.5 Cystoscopy may be used to visualize lesions, obtain biopsies, resect masses, perform lithotripsy, as an adjunct to voiding hydropulsion, perform artificial insemination, and to deliver submucosal bulking agents to treat urinary incontinence.6
Limitations of Cystoscopy Cystoscopy requires general anesthesia for optimal urethral relaxation and patient restraint. It is most useful to evaluate the lower urinary tract and has limited use in lesions of the upper urinary tract. Biopsies can be obtained through the cystoscope; however, only small pieces of tissue are retrieved. Cystoscopy also requires specialized equipment and advanced training of both the operator and the assistant. Although the technique is not technically demanding, it does require education and experience to obtain good images and interpret the image findings. Cystoscopy performed in patients with recent (within 7 days) urinary tract surgery or in patients with urinary tract rupture can result in leakage of irrigation fluid into the abdomen.
Diagnostic Tests Used in Conjunction With Cystoscopy
Figure 3 Image capture. Images of the lower urinary tract may be viewed through the eyepiece of the cystoscope or via camera equipment attached to the cystoscope eyepiece. Still images or video images may be captured in a variety of formats depending on the equipment used.
Urodynamic studies (urethral pressure profiles and cystometrograms) are also used as adjuncts to cystoscopy to diagnose functional abnormalities of the lower urinary tract.
Variants of Normal
Cystoscopy is best used in conjunction with other diagnostic tests and not alone. Urinalysis should always be performed to identify abnormalities in the urine and urine culture to rule out urinary tract infection. Abdominal radiographs are helpful to characterize the size, shape, and location of the kidneys, ureters, bladder, and urethra. Radiopaque stones may also be identified. Contrast studies and abdominal ultrasound may be useful to identify abnormalities in ureter location, nonradiopaque stones, or mass lesions. Computed tomography is useful to diagnose subtle anatomic abnormalities such as ectopic ureters.7
It is important to be aware of normal variability of anatomy and imaging artifacts found in cystoscopy. The bitch in estrus will have a large flap of hyperplastic tissue covering the external urethral orifice that may be mistaken for a mass lesion (Fig. 14).3 Lipid droplets (Fig. 15) and air bubbles (Fig. 16) are commonly encountered and should not be mistaken for stones. Bands of tissue commonly referred to as frenulums, remnants of paramesonephric septae, or hymenal folds may be seen crossing the vaginal opening (Fig. 17).3 Their only clinical significance appears to be impairment of breeding; however, wide bands are often seen in patients with ectopic ureters (Fig. 18). In some dogs, there appears to be a fibrous band of tissue
Figure 2 Light sources. Many different light sources are available for use in cystoscopy. Xenon light sources are generally considered optimal and are available from several different companies. Some newer light sources have automatic light adjustment, but most require that an assistant adjust the light level throughout the examination.
Figure 4 Biopsy instruments. Most cystoscopes have an instrument channel that will accommodate a biopsy instrument. The cystoscope can be used to select an optimal location for biopsy and to direct the biopsy instrument.
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Figure 5 Female cystoscopy report. It is important to have a consistent and systematic procedure for the cystoscopic examination. Having a standardized cystoscopy report form can ensure that all anatomic structures are evaluated and all abnormalities are recorded.
encircling the vagina (Fig. 19). This band of tissue is seen in both normal dogs and dogs with signs of lower urinary tract disease.
Cystoscopic Lesions Lesions commonly identified with cystoscopy include bladder and urethral stones (Figs. 20 and 21), neoplasia in the bladder or urethra (Figs. 22 and 23), cystitis (Fig. 24), and anatomic abnormalities such as ectopic ureters (Fig. 25).8 Renal hematuria (Fig. 26), urethral strictures (Fig. 27), foreign material (Fig. 28), proliferative urethritis (Fig. 29), inflammatory bladder masses (Figs. 30 and 31) (ie, polyploid
cystitis), mucosal abscessation (Fig. 32) and ureteroceles may also be identified with cystoscopy.9-12
Advanced Diagnostic Techniques and Interventions Biopsy Some cystoscopes have instrument channels capable of fitting biopsy instruments. This allows the examiner to obtain tissue samples of any lesions identified cystoscopically. The drawback is that only very small pieces of tissue can be obtained in this manner. Biopsies may also be obtained through
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Figure 6 Male cystoscopy report.
blind or ultrasound-guided traumatic catheterization after completion of the cystoscopy procedure.
erinary medicine.16 This type of therapy is most often palliative, but may be useful in cases of nonoperable bladder tumors or with pedunculated polyps.
Voiding Hydropulsion Cystoscopy may be used to identify bladder calculi and evaluate them for suitability for hydropulsion. Passing the cystoscope through the urethra may also improve dilation and lubrication of the urethra for stone passage. Finally, the cystoscope may be used to ensure that all stones have been evacuated from the bladder; this is especially helpful in patients with many small stones.
Ureteral Catheterization Some ureters are dilated to the extent that a cystoscope can be passed up the ureter. Once the cystoscope is in the ureter, urine samples may be sterilely obtained by attaching a syringe to the instrument channel. A technique for cystoscopeguided catheterization of the ureters has also been described in dogs.17,18
Dilation of Urethral Strictures Traumatic urinary catheterization, previous surgery, or stones lodged in the urethra may lead to urethral stricture. Proximal strictures may potentially be dilated by passing balloon catheters into the stricture and inflating the balloon. Cystoscopy aids in identification of strictures and characterization of their location and severity. The area should also be examined after dilation via cystoscopy.
Lithotripsy Cystoscopy guided lithotripsy probes may be used to break up bladder stones that are too large for hydropulsion. Techniques using electrohydraulic and laser lithotriptors have been described in dogs.13-15
Polyp or Mass Resection Electrocautery and cystoscopy-guided laser therapy to remove polyps and bladder masses have been reported in vet-
Submucosal Injections Submucosal bulking agents may be injected into the urethra to narrow the urethral lumen. Teflon, glutaraldehyde cross-linked collagen, and A-cell have all been used as submucosal bulking agents to treat urinary sphincter mechanism incompetence and decrease clinical urinary incontinence.19,20 The proximal urethra is visualized through the cystoscope and a needle is passed through the instrument port. Collagen or other material is loaded into the needle and the needle is inserted submucosally. Collagen is injected until a visible bleb of mucosa protrudes across at least 50% of the urethral lumen (Fig. 33). The blebs are placed in a clover pattern until 3 blebs have been placed and the lumen is completely occluded (Fig. 34). The bladder is expressed to verify that urine can pass through the collagen site and the patient is hospitalized until they urinate on their own.
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Figure 6 (Continued)
Potential Complications and Troubleshooting Cystoscopy Inability to Enter the Urethra Inability to enter the urethra is the most common complication of cystoscopy. Patient versus cystoscope size is the most important factor determining whether or not the cystoscope can be passed into the urethra and is the reason that several different sizes of cystoscopes are needed for successful procedures on a variety of patients. It is also important to remember that the viewing angle on the cystoscope is 30°. Two other reasons for failure to enter the urethra are direction of the cystoscope ventrally into the clitoral fossa (Figs. 35 and 36) or dorsally and cranially into the vagina that contains a dorsal ridge similar to that of the urethra.
Figure 7 Male dog cystoscopy procedures. In the male dog, the penis is extruded from the prepuce by an assistant while the examiner passes the cystoscope up the urethra. Fluid is injected through the instrument port to distend the urethra and ease the passage of the cystoscope. The instrument is manipulated to keep the image of the urethral lumen in the center of the screen.
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Figure 8 Male cat cystoscopy procedures. Just as in the male dog, the male cat penis is extruded from the prepuce and the flexible cystoscope is directed up the urethra while fluid is simultaneously infused to distend the urethra and ease the passage of the cystoscope. A mosquito hemostat or stay sutures secured to the prepuce may be necessary to maintain extrusion of the penis throughout the examination.
Poor Image Quality Poor image quality may be the result of imaging or patient factors. The image quality may be affected by the level of illumination, camera focus or lubricant obscuring the view. Patient factors include the degree of bladder distension, bladder hemorrhage (especially with distension), failure to distend the vaginal vestibule with fluid, or large amounts of debris in the urine. The bladder must be fully distended, but not so much that bladder hemorrhage occurs. The risk of hemorrhage can be minimized by periodically having an assistant pal-
J.S. Messer, D.J. Chew and M.A. McLoughlin
Figure 10 Vaginal vestibule. The appearance of the normal vaginal vestibule when distended with fluid. The vagina is located at the top of the screen, the cingulum is the band of tissue between the vagina and the urethra and the external urethral orifice is the opening in the middle of the image.
pate the bladder for size and drain fluid out of the bladder when it becomes too large. Bladder hemorrhage can be decreased by infusing chilled saline into the bladder and flushing the bladder. The use of cooled fluids requires close attention to patient body temperature since they can become hypothermic quickly; this is particularly a problem in small patients. It is important to select the largest cystoscope that can be easily and atraumatically passed into the urethra. Distending the vaginal vestibule with fluid in females improves the ability to visualize and enter the external urethral orifice. The male urethra should also be distended with fluid as the cystoscope is passed up its length. When debris in the urine compromises image quality, flushing the bladder with fluid can dramatically improve visualization.
Urinary Tract Infection Urinary tract infection can be a complication of cystoscopic procedures. It is uncommon when strict sterile pro-
Figure 9 Female cystoscopy procedures. The cystoscope is directed slightly dorsally to enter the vaginal vestibule. The vulvar labia are pressed firmly closed and retracted slightly to form a chamber that is distended with irrigation fluid.
Figure 11 Urethra. The normal female urethra is characterized by smooth, pale pink mucosa and a dorsal urethral membrane. The male urethra appears similar, but the urethral lumen is smaller and less distensible.
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59 Table 4 Indications for Cystoscopy
Figure 12 Normal location of the ureters within the bladder. The ureters are located just inside the bladder neck in the trigone. They are c-shaped and the open areas of the c’s face each other; both ureters are located in the same plane within the bladder. The right ureter is located on the right side of the screen and the left ureter on the left side of the screen.
cedures are followed to minimize contamination of the lower urinary tract. The large volumes of fluid used to flush the bladder and urethra are also helpful to minimize bacterial contamination. Routine use of a broad-spectrum antibiotic (amoxicillin) for 5 to 7 days postprocedure is recommended.
Damage to the Lower Urinary Tract Damage to the lower urinary tract as a result of cystoscopy is rare; however, perforation of the urethra (Fig. 37), bladder rupture, or lodging of the cystoscope in the urethra is possible.21 Proper technique and selection of equipment appropriate to the patient are the best way to minimize the risk of damage to the lower urinary tract. The
Disorders of micturition Pollakiuria Stranguria Incontinence Abnormalities of the urine stream Abnormalities of urine composition Hematuria Calculi Abnormal cells in the urine sediment Chronic or recurrent urinary tract infections Investigate anatomy Obtain urine from bladder or ureters for analysis and culture Identify mass lesions or calculi predisposing to infection Evaluation for evidence of cystitis or mucosal abscessation Trauma to the lower urinary tract Bladder rupture Avulsed ureters Urethral perforation Urethral obstruction Verify obstruction Relieve obstruction Verify resolution of obstruction Obtain samples of calculi, plugs, or masses causing urethral obstruction Urethral stricture Mass lesions identified using ultrasound or contrast radiography Verification of the lesion Characterization of the extent of the lesion Biopsy of lesion Anatomic abnormalities identified using ultrasound or contrast radiography Vaginal septa Ectopic ureters Urachal diverticula Adjunct to urodynamic studies Investigate presence of anatomic abnormalities or mass lesions that may influence results of urethral pressure profilometry or cystometrography Evaluation of the distal reproductive tract in females Stage of estrus cycle Evidence of vaginitis Interventions Lithotripsy Removal of pedunculated masses or polyps Implantation of submucosal bulking agents to treat incontinence
cystoscope should never be advanced with more than gentle pressure.
Conclusions Figure 13 Normal vagina. The caudal female reproductive tract can be examined via cystoscope from the vagina to an area just caudal to the cervix called the pseudocervix. The vagina has numerous mucosal folds and with distension, a dorsal membrane similar to that seen in the urethra, may be appreciated. The appearance of the mucosa changes during the estrus cycle.
Cystoscopy can be an invaluable adjunct to routine diagnostic procedures of the lower urinary tract in dogs and cats. It allows direct visualization of the areas of interest, enables biopsies of mass lesions and provides opportunities for intervention such as lithotripsy and submucosal collagen injections. Specialized equipment and advanced training are required for optimal cystoscopy results.
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Figure 14 Bitch in estrus. The mucosal folds of the vagina change in appearance with the stage of the estrus cycle. During estrus, there is often a large, hyperplastic fold of mucosa covering the external urethral orifice.
Figure 15 Lipid droplets. Lipid droplets are a normal component of feline urine and should not be mistaken for stones in the urinary bladder. The droplets should be found on the up-side of the bladder.
Figure 16 Air bubbles. Air bubbles are frequently introduced during cystoscopy. Bubbles are found on the up-side of the bladder and may aid in orientation during the examination.
J.S. Messer, D.J. Chew and M.A. McLoughlin
Figure 17 Vaginal vestibule with thin frenulum. Small bands of tissue, frenulums or hymenal remnants, are frequently found crossing the vagina. Unless the tissue distorts the anatomy of the urethra, it is of no clinical significance.
Figure 18 Vaginal vestibule with wide frenulum. Wide bands of tissue crossing the vagina are frequently found in patients with ectopic ureters. The opening to an ectopic ureter can be seen dorsal to the urethra just inside the external urethral orifice.
Figure 19 Vaginal vestibule with cingulum. The cingulum is the band of tissue between the vagina and urethra. Fibrous rings are frequently found encircling the vagina in normal dogs and dogs with clinical signs of lower urinary tract disease.
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Figure 20 Bladder stones in a dog. Bladder calculi are found in various shapes and sizes; these are calcium oxalate stones in a dog. Cystoscopy can be used to aid in hypdropulsion of small stones, to collect stones for quantitative analysis, or to perform intracorporeal lithotripsy and break stones into pieces small enough to remove via hydropulsion.
Figure 21 Bladder stones in a cat. These are calcium oxalate stones found in the bladder of a female cat. Voiding hydropulsion was used to remove the stones from the bladder. The gross appearance of stones is suggestive, but not diagnostic for their mineral content. Quantitative mineral analysis should always be used to identify the stone type and guide therapy.
Figure 22 Transitional cell carcinoma in a dog urethra. This image is from the urethra of a dog that had transitional cell carcinoma in both the urethra and urinary bladder. The cystoscope is an excellent tool to identify disease in the urethra and obtain biopsies of lesions.
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Figure 23 Transitional cell carcinoma in a dog bladder. Transitional cell carcinoma found in the bladder of a female dog. Cystoscopy can be used to biopsy masses identified using ultrasound or contrast radiographs. The magnification associated with cystoscopy images often allows identification of lesions within the urethra that are too small to identify with other imaging modalities. Bladder masses are frequently associated with extension of neoplastic tissue into the urethra.
Figure 24 Cystitis. This image was taken of a bladder from a female cat with signs of lower urinary tract disease and a negative urine culture. The prominent vascularity and glomerulations (submucosal petechial hemorrhages) seen here are characteristic of cystitis.22 Cystitis is also associated with increased mucosal friability and mucosal ulceration with subsequent hemorrhage frequently occurs with urethral and bladder distension. Lesions consistent with cystitis may be seen with feline lower urinary tract disease, bladder infection or sterile canine cystitis.
Figure 25 Ectopic ureters. Ectopic ureter in a female dog terminating in the proximal urethra.
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Figure 26 Renal hematuria. Cystoscopy may be used to identify the source of renal hematuria and to catheterize the ureters to obtain urine samples.
J.S. Messer, D.J. Chew and M.A. McLoughlin
Figure 29 Proliferative urethritis. Proliferative urethritis in a female dog; notice the proliferative tissue covering the external urethral orifice.
Figure 30 Benign inflammatory bladder mass. Many different types of benign and malignant masses can be visualized and biopsied via cystoscopy. This mass was composed of inflammatory tissue that formed along the suture line from a previous cystotomy. Some masses will take on the appearance of polyps within the bladder (polyploid cystitis). Figure 27 Urethral stricture. Stricture of the urethra in a male cat associated with perineal urethrostomy surgery.
Figure 28 Foreign material. Foreign material left in the urethra postintraurethral ureterectomy surgery for an ectopic ureter. Suture material can act as a nidus for recurrent urinary tract infection.
Figure 31 Benign inflammatory bladder mass. This mass consisted of inflammatory tissue that formed at the opening to the right ureter.
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Figure 32 Bladder wall abscessation. Images of the bladder wall from a dog with recurrent urinary tract infections. The bladder has markedly increased vascularity and 2 abscesses can be appreciated in the mucosa.
Figure 33 Collagen implantation. This image shows submucosal collagen injection in the urethra of a female dog. A needle is loaded with collagen and passed through the instrument port of the cystoscope. One operator directs the cystoscope while the other inserts the needle under the mucosa and injects collagen.
Figure 34 Collagen implantation. Ideal collagen placement results in complete occlusion of the urethral lumen. The bladder is expressed following the procedure to ensure that urination can occur, and patients are hospitalized until they urinate on their own.
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Figure 35 Appearance of the clitoral fossa. The clitoral fossa is a blind pocket of tissue located ventral to the vaginal vestibule.
Figure 36 Mucosal folds in the clitoral fossa. The clitoral fossa contains mucosal folds that may mimic the collapsed mucosa of the vaginal vestibule.
Figure 37 Partial urethral perforation. Complications associated with cystoscopy are rare. However, partial or complete perforation of the lower urinary tract can occur. The image shown here is iatrogenic partial perforation of the urethra of a female dog following a cystoscopy procedure. Proper equipment size and technique will decrease the risk of trauma to the urinary tract.
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