Indications for Cystoscopy

Indications for cystoscopy include chronic or recurrent urinary tract infections, hematuria, dysuria, stranguria, pollakiuria, trauma, calculi, incontinence, abnormal morphologic findings in the urine sediment, and abnormal imaging findings on abdominal radiographs and ultrasounds (see Box 17-1).^11,12 Transurethral cystoscopy with a rigid cystoscope is the preferred approach for female dogs and cats (Figures 17-1 through 17-6). The urethra and bladder of male dogs can be studied with a flexible urethroscope passed through the urethra (see Figure 17-4). A small diameter semirigid scope can be used in male cats, unless they have had an urethrostomy (Figure 17-7). Routine practice after perineal urethrostomy in the cat is to examine the urinary system with a 1.9-mm rigid cystoscope. Most small animal patients can also be examined with a laparoscopic-assisted cystoscopy.⁶ Laparotomy for removal of calculi from the renal pelvis and ureter is facilitated by the use of small arthroscopes or cystoscopes (Figure 17-8). When the attempt is made to diagnose urinary problems, cystoscopy should be considered essential. For the previously mentioned problems, other diagnostic procedures include a history, physical examination, complete blood count, serum chemistry profile, and urinalysis. If the problem is assumed to be difficult to either diagnose or resolve, cystoscopy is a quick and direct approach for diagnosis.¹¹ In addition, when cystoscopy is used for diagnosis, the operating channel provides an option for passing graspers, basket catheters, injection needles, scissors, and energy devices for treatments (see Box 17-2 and Figure 17-6). The only significant concern is the need for general anesthesia. Because the procedure is typically quick and minimally invasive, anesthesia is usually easily justified.

Figure 17-1 Rigid endoscopes used for cystoscope sheaths for cystoscopy in female dogs and cats, as well as laparoscopic-assisted cystoscopy. Each has 30-degree viewing and utilizes the same camera and light cable. They are 1.9, 2.7, and 3.5 or 4 mm in diameter. The 1.9-mm size may also be integrated into the cystoscopy sheath, which makes it more durable because it is slender and prone to bending.

(Photograph by Chris Herron © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-2 Standard sheaths for cystoscopy for use with endoscopes (see Figure 17-1). Each has an inflow and outflow port, as well as an operating port for instruments. The sheath for the 1.9-mm scope is a 10F size with a 3.5F operating channel, which will accommodate a 400-μm diode laser fiber; the sheath for the 2.7-mm scope is a 14.5F size with a 5F operating channel, which will accommodate a 800-μm fiber, and sheaths for the 3.5- to 4-mm scopes range from 17F to 24F.

(Photograph by Chris Herron © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-3 Specialized sheaths for cystoscopy can be used with the 3.5- to 4-mm telescopes. These include a deflecting bridge for selective ureteral catheterization. Injection augmentation (A) and transcervical insemination (B) (see Chapter 18). During injection augmentation performed by a right-handed operator, the cystoscope is held in the left hand and a syringe attached to the needle is slowly injected with the right hand.

(Photograph by Chris Herron © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-4 The flexible 2.5- to 2.8-mm fiberoptic urethroscope is used to examine the urethra of male dogs; the urethra is approached from either the tip of the penis or the bladder during laparoscopic-assisted cystoscopy. This is available in 70- and 100-cm lengths. The focus on the urethroscope should be adjusted before connecting to the camera, and then the only focusing is with the camera. The flexible tip can bend 90 degrees in one direction (inset). A full 360-degree examination can be done by manually rotating the scope from outside the patient. The operating channel accepts 3F instrumentation, which should only be advanced through the scope while it is straight or only slightly bent.

(From Rawlings CA: Endoscopic removal of urinary calculi, Compend Cont Ed Pract Vet 31(10): 476-484, 2009.)

Figure 17-5 It is very helpful to be slightly ambidextrous, being able to hold and manipulate the cystoscope in either hand depending on the needs for the procedure. Most cystoscopy is performed with the dominant hand; here the right hand is being demonstrated. Injection augmentation, laser treatment, transcervical insemination, and biopsies are done with the right hand on the accessory instrument while the cystoscope is in the left.

(Photograph by Chris Herron © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-6 A, The 2.7-mm cystoscope and sheath are being used to pass a 5F biopsy forceps. Although cystoscopic biopsy can be done by one person, it is better to have a second person to open and close the alligator handle and then to remove and replace the forceps in the operating channel. The operator is responsible for positioning the cystoscope and biopsy device. B, A basket catheter for calculi removal shown here with and without calculi.

(A, Photograph by Chris Herron © 2010 University of Georgia Research Foundation, Inc. B, From Rawlings CA: Endoscopic removal of urinary calculi, Compend Cont Ed Pract Vet 31(10):476-484, 2009.)

Figure 17-7 A 1-mm semirigid telescope with 0-degree viewing.

(From McCarthy TC, Veterinary endoscopy for the small animal practitioner, ed 1, St Louis, 2004, Saunders.)

Figure 17-8 A 1.9-mm cystoscope or small arthroscope is used for nephroscopy to remove calculi during a laparotomy. These scopes can be used to examine lumen of dilated renal pelvis and ureters during laparotomy. This approach is similar to arthroscopy and can be used for calculi removal using grasping forceps and calculi basket devices. A, Grasping forceps to remove calculi using a second small opening through the renal parenchyma or going parallel to the scope. B, Basket catheter passed through the cystoscope’s operating channel to remove calculi.

(From Rawlings CA: Endoscopic removal of urinary calculi, Compend Cont Ed Pract Vet 31(10):476-484, 2009.)

Dysuria and Stranguria

Dysuria and stranguria are difficult urination or straining to urinate. Despite repeated attempts to void, the patient produces a typically small volume of urine. Dysuria is caused by obstructions, inflammation, or irritation. The most common cause of inflammation and a frequent cause of straining are urinary tract infections. Obstructive dysuria is most commonly produced by calculi (discussed later in this chapter) or tumors of the urethra or bladder outflow tract (Figure 17-9). Other causes of obstructive dysuria are prostatic abscesses or cysts, granulomatous masses, strictures (Figure 17-10), trauma, fibrotic bands of tissue (Figure 17-11), and urethral contraction due to bladder–urethral sphincter reflex dyssynergia. Masses obstructing the bladder outflow area can also include inflammatory polyps and blood clots.

Figure 17-9 Ten-year-old female spayed Wirehaired Dachshund with hematuria, frequent attempts to void, and occasional inappropriate urination. Small cystic calculi and a urinary tract infection were present. Cystoscopy was used to find proliferative masses in the urethra and small calculi, which were removed. The histologic diagnosis was transitional cell carcinoma.

(Photograph © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-10 Five-year-old intact male English bulldog who started dribbling urine 48 hours before referral examination. There were repeated attempts to void without a good urine stream. No signs of azotemia were present, but small calculi were present in the bladder and urethra. Urethral calculi were removed from the os penis area with a basket catheter, and bladder calculi were removed by laparoscopic-assisted cystoscopy. A urethroscope was used to find a mild stricture and urethral injury just caudal to the os penis.

(Photograph © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-11 Six-year-old female spayed Dachshund with dysuria and frequent yelping when placed into left lateral recumbency. Hematuria was present on urinalysis, but no abnormalities were seen on radiography or ultrasonography. A, The cranial area of the urethra had a stricture. B, The fibrous stricture was resected with the use of a diode laser. C, No stricture was present when cystoscopy was performed 1 year later.

(Photographs © 2010 University of Georgia Research Foundation, Inc.)

Straining can be produced by vaginal and vestibular masses (Figure 17-12), but these masses seldom produce complete urinary obstruction.

Figure 17-12 Twelve-year-old female Shih Tzu, who had had three litters, now has a mass periodically protruding from the vulva. A, Cystoscopy found the mass attached to the cranial region of the vagina. B, Ovariohysterectomy, which included this region of the vagina, removed the mass, a vaginal fibroma.

(Photographs © 2010 University of Georgia Research Foundation, Inc.)

The initial evaluation of dysuria should determine whether the patient is uremic and whether urine is being retained. Residual volume is measured by catheterization or ultrasonography after the patient is permitted to void. Patients with high residual volume usually have obstructive dysuria or neurologic deficits. Straining patients with a low residual volume are typically those with inflammation, most likely caused by infection. Questions about the patient’s history should include:

1. “What are the urinary signs?”

2. “Has the patient had prior urinary disease?”

3. “How frequently does the patient attempt to void?”

4. “How much urine is produced?”

5. “Does the patient strain to void?”

6. “Is defecation normal or changed?”

7. “Is there blood or discoloration of the urine?”

8. “When does blood appear to be within the urine stream?”

9. “Has there been any history of trauma?”

10. “Has the patient had any generalized disease signs, such as vomiting, weight loss, or anorexia?”

The physical examination should include all systems, and the emphasis should be on the urogenital tract. First, is the bladder distended? If the bladder is distended because of either obstruction or neurologic deficits, care should be taken to avoid rupture of the bladder. The urethra is palpated, and the external orifice is examined. Examination should also include rectum palpation. These examinations can also include urethral catheterization and a neurologic examination. Care should be taken during catheterization and must be stopped if resistance is encountered. Radiographs should be taken, and in male dogs either urethroscopy or positive contrast urethrography should be considered. After a complete history and physical examination, the mechanism of the dysuria can usually be characterized as an obstruction with a full bladder or an urgency with an empty bladder.

Urinalysis is best obtained by centesis, and a portion of the urine should be submitted for culture and sensitivity testing. Cystocentesis is a relatively safe procedure, especially when ultrasound is used. The standard blood tests should also be done. Patients with obstructive signs require emergency measurement of blood urea nitrogen (BUN), creatinine, and electrolyte concentrations. The standard of practice for straining dogs includes survey radiographs. Ultrasonography is also noninvasive and is an excellent technique for examining the urinary tract from the kidneys to the external orifice of the urethra. Before and usually in lieu of proceeding to contrast procedures, CT, or magnetic resonance imaging (MRI), the next diagnostic procedure is cystoscopy.

Cystoscopy can diagnose the cause of urinary obstructive disease and has the potential to provide treatment in many patients. In female dogs, cystoscopy can be used to diagnose calculi or cancer, specifically transitional cell carcinoma (see Figure 17-9), as the cause of obstructive dysuria.^13,14 Other causes include strictures (see Figure 17-10), other anatomic abnormalities, and extraluminal masses. Patients with urinary tract inflammation will not have obstructions but will have signs of inflammation. Calculi can be diagnosed in female cats by rigid cystoscopy and in male dogs by flexible urethroscopy. Transurethral cystoscopy is the preferred calculi removal treatment in female dogs when the calculi are only two to three times the diameter of the largest cystoscope appropriate for the patient. A three- or four-wire basket catheter is passed through the cystoscope’s operating channel. Urethral calculi in male dogs can sometimes be removed with the use of a basket catheter and flexible urethroscope. Calculi in male cats may be removed by transurethral cystoscopy when a perineal urethrostomy has also been performed as a part of the case management. Cystic calculi and most urethral calculi can be removed by a laparoscopic-assisted cystoscopy in both male and female dogs and cats.

Endoscopic surgical treatment can also be done for strictures, intraluminal masses, intraluminal foreign bodies, and transitional cell carcinoma. Foreign bodies may be removed by wire baskets and grasping forceps passed through the operating channel. Strictures may be resected and transitional cell carcinoma debulked with a diode laser (Figure 17-13), or both may be treated by stenting. See the “Minimally Invasive Options for Urinary Obstructions, Including Calculi” section. Although both techniques are new, preliminary clinical experience with urethral stents and laser resection of transitional cell carcinoma has demonstrated prolongation of quality of life. Some masses can be resected by traditional surgery.

Figure 17-13 Two-year-old spayed female Doberman Pinscher with incontinence, characterized by frequent bed soaking and dribbling four to five drops after voiding. A, Cystoscopy was used to find a long tag of tissue originating in the cranial region of the urethra; the other end was just inside the urethra. A loop of the tissue exited the urethral meatus. B, The origin and insertion were resected with the use of a diode laser aided by traction with a mosquito hemostat. Histologic diagnosis was lymphocytic, plasmacytic inflammation of an apparently congenital lesion. Incontinence resolved.

(Photographs © 2010 University of Georgia Research Foundation, Inc.)

Recurrent Urinary Tract Infection and Inflammation

Recurrent infections may produce a range of signs from mild straining to frequent urination. Many dogs attempt to void repeatedly, frequently delivering small amounts of urine. These repeated attempts to void should be contrasted with the traditional male marking activity. After the diagnostic studies already described, cystoscopy can usually confirm urinary tract inflammation by the presence of inflammatory lymphocytic or plasmacytic foci (Figure 17-14). Dogs with recessed or “hooded” vulvas frequently have local pyoderma and ascending infection. Inflammatory foci are commonly found in the vestibule, and these foci can spread up the urethra and into the bladder. Cystoscopy is frequently combined with episioplasty to remove the excessive perivulvar skinfold.

Figure 17-14 Seven-year-old female spayed Golden retriever who had had bilateral neoureterostomy performed intravesicularly at 8 months of age as treatment for bilateral ectopic ureter. Incontinence and infection were frequent after surgery. A, The vulva was small and recessed. B, Cystoscopy found extensive areas of lymphocytic, plasmacytic inflammatory foci in addition to a fenestrated ureter and a broad mesonephric septal remnant at the vestibulovaginal junction. C, After a diode laser resected these areas, and urethral injection augmentation was done, incontinence resolved for 3 weeks and then slowly returned. A colposuspension and episioplasty were recommended.

(Photographs © 2010 University of Georgia Research Foundation, Inc.)

There are multiple anatomic reasons for recurrent infections, but cystoscopy can only be used to eliminate the following causes: calculi, foreign bodies, inflammatory polyps, tumors, incontinence, and other anatomic abnormalities. Primary treatment should be attempted. If no apparent anatomic cause is found, a biopsy of the bladder mucosa can be obtained for tissue culture. In many patients, management must focus on aggressive monitoring and appropriate antibiotic treatment. These patients should have regular cystocentesis for urinalysis and culture. If appropriate urinary tract infection management has been done and infection recurs, cystoscopy can be repeated.

Hematuria and Other Abnormal Discharges

Hematuria and purulent discharges can be produced in the urogenital system at any point from the kidney to the external genitalia. The anatomic site can sometimes be localized depending on the timing of hemorrhage with respect to urination. Blood dripping frequently or at the start of urination is usually more external, from the prostate to the tip of the urethra, prepuce, or vestibule. Blood seen throughout urination is usually from the bladder or kidneys, cranial to the urethral sphincters. The source of blood may be from trauma, neoplasia, or polyps or may be idiopathic (Figure 17-15).¹⁹ Survey radiography and ultrasonography should be done, but the most diagnostic technique is usually cystoscopy. Masses can be identified, and diagnostic samples can be obtained for histologic evaluation. Traumatic injuries are usually just verified, but catheterization until the injury heals or surgery is occasionally appropriate. Some dogs develop renal origin hematuria, and the location can be easily identified with cystoscopy (Figure 17-15).¹⁹

Figure 17-15 Four-year-old spayed female Shepherd cross dog had been treated for persistent urinary tract infection. There were frequent attempts to void, and hematuria could be seen during urination. There was no evidence of urinary tract infection when examined as a referral. Cystoscopy was used to identify bloody urine exiting the right ureter (A) but not the left (B) resulting in a diagnosis of essential unilateral hematuria.

(Photographs © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-16 A, The patient for cystoscopy is placed on her back with the vulva at the end of the table. The monitor should be opposite the patient from the operator, and a large, draped instrument table should be placed between the endoscopy tower and the patient. B, The patient’s vulvar area is modestly clipped and surgically prepared before draping. It is essential that the vulva be closed securely after cystoscope insertion so that fluid is prevented from escaping the optical space. For more information on the cystoscopy technique, visit the companion website.

www.tamssmallanimalendoscopy.com

(Photographs © 2010 University of Georgia Research Foundation, Inc.)

Contraindications

The primary contraindications are patient size, lack of instrumentation, and lack of expertise. I have rarely encountered a patient in which general anesthesia precluded cystoscopy. Cystoscopy of the female is probably the quickest and easiest endoscopic technique to learn. After inanimate model training during training laboratories, cystoscopy is the first procedure taught when the student progresses to patients. Some individual dogs and cats may be more challenging, but patience and gentle, subtle movements frequently allow the urethra to be entered. Strictures and tumors can increase cystoscopy difficulty, but cystoscopy has already produced a diagnosis in those cases. An appropriate range of cystoscopes are needed for a wide range of patient and urethral sizes. Without a flexible urethroscope, the entire length of the male dog’s urethra cannot be examined.

Instrumentation

Transurethral cystoscopy in the female dog and cat is performed with a rigid cystoscope.^11,12,20 All have a 30-degree angle, which provides side viewing as well as enough forward viewing to direct the scope into the urogenital system. The side viewing increases the examination capabilities because the scope can be rotated 360 degrees. Cystoscopes consist of a scope that is inserted into a sheath. Cystoscope sheaths have two fluid ports: one is for fluid infusion and the other is for outflow. Infusion of saline or a balanced electrolyte solution permits flushing and distension of an optical space. It is important to avoid overdistension of the bladder, which is drained via the outflow port. The most frequently used scope is a 2.7-mm, 18-cm-long cystoscope with a 14.5F sheath (see Figure 17-1). It can be used in female dogs as small as 5 kg. In dogs more than 15 to 20 kg, this 2.7-mm cystoscope can usually be used to examine the urethral and bladder outflow but is too short to do a thorough bladder examination. In these larger female dogs, a 3.5- or 4-mm, 30-cm-long cystoscope is preferred. In female dogs smaller than 5 kg and in female cats, a 1.9-mm, 18-cm-long cystoscope is required. Even this scope becomes difficult to use in females less than 2 kg. Because the 1.9-mm scope can be broken, it is also provided in an integrated fashion with the scope and sheath as a unit. Specialized cystoscopes can be useful, especially for injection augmentation and selective catheterization of ureters.²¹

Transurethral cystoscopy of male dogs is done with a flexible urethroscope. My preference is a 2.5-mm by 70- or 100-cm-long fiberoptic scope (see Figure 17-4). This scope tapers from 2.5 mm at the tip to 2.8 mm near its eyepiece. This scope can be passed up the urethra of a male dog over 10 kg and sometimes in dogs as small as 6.5 kg. It can also be passed from the bladder to the region of the os penis during laparoscopic-assisted cystoscopy in smaller dogs. The advantage of the fiberoptic scope is the ability to use the standard camera and light cable connected to either the cystoscope or the laparoscope during a laparoscopic-assisted cystoscopy. This reduces the instrumentation for examination of the bladder and urethra during this procedure as compared with use of the flexible scope, which requires a separate video endoscopy system. Male cats can be examined with a 1.2-mm-diameter flexible cystourethroscope or a semirigid 1-mm scope.¹²

Patient Evaluation and Preparation

All dogs and cats undergoing cystoscopy should have a complete history, physical examination, a complete blood count, urinalysis, and serum chemistry tests. The chemistry tests and imaging tests vary depending on the animal’s problem, as already discussed. Urinary tract infections should be appropriately managed, but this may be difficult depending on the cause of the infection. Some conditions, such as neoplasia and massive hemorrhage, are indications for a platelet count, coagulogram, and, possibly, mucosal bleeding times. Patients should be fasted from solid foods for 12 hours, unless medical status requires more frequent feeding. Water is also withheld, but shorter times are preferred for patients with renal disease, which reduces the urine concentration. Antibiotic administration is routinely used during cystoscopy.

Anesthesia and Monitoring

General anesthesia is required. No special anesthetic protocol is universally preferred. Drug selection and types of monitoring should be based on the animal’s condition and the expertise of the practice. The patient should be permitted to urinate before cystoscopy, and the bladder should be emptied at the end of cystoscopy.

Cystoscopic Techniques

Rigid transurethral cystoscopy is selected for female dogs and cats and for male cats after perineal urethrostomy. The ability to provide high flows quickly provides a clear optical media. The 30-degree viewing with a rigid scope provides excellent images of the entire urogenital system. Because of the long and circuitous urethra, male dogs require the use of flexible endoscopy. This provides lower infusion rates and limited ability to examine the entire bladder. Another alternative for male dogs and cats is laparoscopic-assisted cystoscopy. This technique is even used for removal of calculi from the urethra or for diagnosis of bladder and proximal urethral masses.

Transurethral Cystoscopy in Female Dogs and Cats

Multiple techniques have been used for transurethral cystoscopy, but I have developed preferences after experimentation with alternatives. The patient is placed on her back with the vulva positioned at the end of the table; the operator is behind the dog, and the monitor is at the patient’s head, opposite the cystoscopy site from the operator (see Figure 17-16, A). A modest amount of clipping is done about the vulva. This area is scrubbed in an effort to reduce contamination. A sterile drape is fenestrated for the vulva and placed over the patient to leave the vulva exposed. Sterile gloves are used (see Figure 17-16, B). Cystoscopic equipment is either sterilized or disinfected with glutaraldehyde (Cidex). These practices are done to limit contamination.

The cystoscope is advanced through the vestibule and into either the urethra or vagina with direct visualization and fluid infusion (Figures 17-17 and 17-18). Although a blunt obturator is routinely included as part of the cystoscopic package, it is not used for dogs and cats. The cystoscope is held in the dominant hand, and the light cable is in the up position. The operator should be looking down or dorsally through the 30-degree scope in the dog placed in dorsal recumbency. To examine areas on either side or ventrally, the operator should rotate the light cable and scope while maintaining the camera in the same orientation. The vulva lips are closed and an optical space is produced within the vestibule by infusion of fluid through the infusion port; this allows the urethra to be seen and entered. Fluid infusion is by gravity flow with either saline, Ringer’s solution, lactated Ringer’s solution, or some sterile isotonic electrolyte fluid (see Figure 17-17). Before either the urethra or vagina is entered, the vestibule should be examined. The urethra is entered after holding the tip of the cystoscope at the urethral orifice so that the urethra can be dilated with fluid infusion. As the cystoscope is advanced, care should be taken not to advance it forward against resistance. The dorsal wall of the urethra can be viewed, but to view the entire urethral lumen would cause the point of the cystoscope sheath to be pushed against the ventral urethral wall when a 30-degree cystoscope is advanced. The entire urethra wall can be easily examined by ventral displacement of the cystoscope’s tip during withdrawal of the cystoscope from the bladder. When the bladder is entered, residual urine is permitted to flow through the outflow port. When the outflow port is open, the inflow port should be closed. Once the bladder is collapsed, the outflow port is closed and inflow is turned on. The flushing procedure is repeated until a clear optical space permits examination of the lining of the urinary system. Care must be taken to avoid overdistension of the bladder. Overdistention can produce mucosal tears in the bladder and can cause difficulties in examining the ureters and cranial portion of the bladder. Dogs more than 20 kg are frequently examined with the 2.7-mm cystoscope because the most critical areas are from the bladder outflow to the exterior, and much of the bladder can be examined if the bladder is only mildly distended. Before or after examination of the urinary system, the vagina is entered and the cystoscope advanced as far cranially as possible. Because this procedure is normally done quickly, it is common to repeat passage of the cystoscope into the bladder so that a thorough examination is ensured. The bladder is emptied on the final examination.

Figure 17-17 Intravenous types of fluids are used for infusion at gravity flow. It is essential that an optical space is maintained by prevention of loss of fluid. Two ports are on the cystoscope: one for inflow and the other for outflow. Flow should be permitted to flow either in or out without both ports being open at the same time. Once the cystoscope is inside the bladder, bladder fluid is permitted to flow out and new fluids infused so that the bladder can be cleared. Care is taken to avoid overdistention of the bladder.

(Art by Kip Carter © 2010 University of Georgia Research Foundation, Inc.)

Figure 17-18 A, During infusion, the cystoscope is advanced dorsally sufficiently to avoid the sub-clitoral fossa. B, The cystoscope is then directed more horizontally during advancement into both the vagina and urethra. The vestibule, vagina, urethra, bladder, and trigone with both ureteral openings must be thoroughly examined.

(Art by Kip Carter © 2010 University of Georgia Research Foundation, Inc.)

All surfaces of the urogenital tract are examined, usually starting just cranial to the clitoral fossa. Typical abnormalities include calculi, tumors, mucosal tears, focal inflammatory lesions, laceration through the urogenital tract wall, and congenital abnormalities. The most common congenital lesions are ectopic ureters, a condition in which the ureters do not enter the bladder outflow tract normally but rather enter distally into the urethra, vagina, or vestibule. Many dogs have a persistent mesonephric septal remnant going from dorsal to ventral at the vestibulovaginal orifice. This remnant may continue cranially in the vagina to appear as a medial septum. Digital images and movies of abnormalities are recorded. In some patients with no apparent lesions, it is helpful to record the normalcy for hospital records and communication with the client.

Biopsy specimens are obtained from tumors and masses. These biopsies are usually done with the largest flexible biopsy cup device that can be passed through the operating channel. These samples are small, requiring as many as 8 or 10 samples for accuracy. Recurrent urinary tract infections can be an indication for a bladder mucosal biopsy for culture and sensitivity testing. My preference is to place these small biopsy specimens on a single foam insert within a biopsy cassette. Larger samples from vestibular and caudal urethral masses can frequently be obtained with the use of a 3-mm oval biopsy forceps passed beside the cystoscope. Having sterilized biopsy cassettes on the sterile back table improves aseptic technique.

The operating channel can also be used to pass other instruments for retrieval of calculi and foreign bodies and for laser treatment of ectopic ureters and masses; an injection needle can also be passed through the channel for submucosal augmentation with bulking solution. These treatments are covered in subsequent sections.

Transurethral Cystoscopy in Male Dogs

The distal portion of the urethra can be examined with the use of a short, rigid scope with a sheath, such as a 1.9-mm cystoscope and various arthroscopes. For a complete urethral examination, a long (70- to 100-cm) urethral flexible scope is used. It is preferable to be able to deflect the tip in at least one direction, for example, neutral to left to right. Rotation of the flexible scope provides the ability to turn the tip in each of four directions. The approach to passing either short, rigid or longer flexible scopes is similar to passing a urethral catheter. Adequate urethral distension frequently requires injection by syringe in addition to the standard gravity infusion. As the urethroscope is being passed, avoid forcing the tip against the wall, which produces a “pink-out.” Manipulation of the urethra and bladder can be helpful while the urethroscope is advanced. This manipulation can be directly on the urethra and penis, rectal palpation of the prostatic urethra, or abdominal manipulation of the bladder. The best examination, images, and movies are obtained as the urethroscope is being withdrawn. Good viewing requires a slow, steady withdrawal with redirection of the tip to retain a luminal view. Within the bladder, a clear optical space must be obtained, which can be difficult to accomplish with the low flows through the 2.5- to 2.8-mm flexible scope. It is helpful to empty and flush the bladder with a urethral catheter before urethroscopy. Examination of the bladder is easier if it is only modestly distended. A thorough examination can be done by moving the tip back and forth and rotating the scope 90 degrees.

Biopsy specimens can be taken with a long, flexible 1-mm (3F) biopsy instrument. Care must be taken when the biopsy instrument is advanced through a bent scope; any resistance is a reason to withdraw the entire scope, reinsert the biopsy instrument into a straight scope, and then readvance the scope. The handle of these smaller biopsy instruments should never be squeezed when taking the biopsy “bite.” Closure must be gentle, and the spring must do most of the “bite” because slight pressure can break the biopsy tips. The operating channel can also be used for graspers and basket catheters. A 5F or larger basket catheter can also be passed beside the urethroscope. The basket is opened and closed while being directly viewed with the urethroscope. Calculi and foreign bodies can be removed with this technique.

Laparoscopic-Assisted Cystoscopy

Calculi too large for transurethral cystoscopic removal in female dogs and cats and calculi in male dogs and cats can be removed with the use of cystoscopy done as a laparoscopic-assisted procedure (Figure 17-19).⁶ The rare contraindications for calculi removal by either transurethral cystoscopic or laparoscopic-assisted cystoscopic techniques are very large calculi and perhaps several dozen calculi in a dog. These calculi may be better removed by traditional cystotomy. Other calculi that would be removed by traditional laparotomy are in patients needing other major abdominal surgeries. Examples include removal of nephroliths along with a nephrectomy. Patients requiring a simple liver biopsy and calculi removal are usually better treated by laparoscopy. Laparoscopic-assisted cystoscopy has also been used to resect masses and to examine the bladder outflow tract.

Figure 17-19 Laparoscopic-assisted cystoscopy is used to examine the bladder, ureteral openings, and urethra, as well as to remove calculi that are too large for removal by transurethral cystoscopy. A, Laparoscopy is done to identify and lift the cranial portion of the bladder to the abdominal wall. B, The caudal trocar site is enlarged enough to permit securing the bladder to the abdominal wall and to perform a minicystotomy for placing the cystoscope into the bladder lumen. C, Calculi are removed with the use of either wire basket catheters through the operating channel or a variety of grasping devices passed parallel to the cystoscope. After the calculi are removed, small calculi can be flushed and aspirated from the bladder. The urethra should be examined with the use of either a rigid cystoscope in a female dog or a flexible fiberoptic scope in the male dog.

(From Rawlings CA, Barsanti JA, Mahaffey MB, et al: Use of laparoscopic-assisted cystoscopy for removal of calculi in dogs, J Am Vet Met Assoc 222:759-761, 2003.)

Control of preexisting urinary infections should be attempted before surgery. If infection persists, a culture of the urine or bladder mucosa should be considered. Regardless of urinary control, the potential contamination dictates the use of antibiotics during cystoscopy.

Two laparoscopic trocars are used for laparoscopic-assisted cystoscopy. The monitor is placed caudal to the patient (see Figure 17-19). Laparoscopic techniques are described in the “Laparoscopic Surgery Introduction” portion of Chapter 15. The trocar for a 5-mm laparoscope is placed on the midline, approximately 3 cm caudal to the umbilicus. The abdomen is insufflated, and the site for the second trocar is selected. This trocar is for a 5-mm laparoscopic Babcock forceps to grasp and lift the cranial region of the bladder to the abdominal wall. This site is on the midline for female dogs and for some male dogs, depending on the position of the prepuce in relation to the cranial portion of the bladder. It is critical that the cranial portion of the bladder is lifted to the trocar site. The site is enlarged sufficiently to expose enough of the bladder so that the bladder can be secured to the exterior. If there is bladder lumen cranial to the trocar site, it is difficult to inspect and remove calculi from the cranial pouch of the bladder. A variety of securing techniques are used to keep the bladder firmly attached to the abdominal wall and prevent urine contamination of the peritoneal cavity. Four quadrate attachments with interrupted cruciate-placed sutures are used, which permits their long tags to be secured to drapes. Some surgeons prefer to place a temporary continuous suture between the bladder and skin. Once the bladder trocar has a secure seal with the abdominal wall, a small cystotomy is performed. A 2.7-mm cystoscope is placed into the bladder via the minicystotomy. For cats and small dogs, a 1.9-mm cystoscope is used. The bladder is lavaged in similar fashion to transurethral cystoscopy. Some clinicians prefer to have a urethral catheter as an additional infusion source. The bladder and entire urethra of female dogs and the prostatic urethra of males are examined with the rigid cystoscope. Calculi are removed with a variety of instruments, depending on the size and number of the calculi. Various alligator forceps, 5-mm Babcock forceps, and arthroscopic grasping forceps are passed parallel to the cystoscope to grasp and retrieve calculi (Figure 17-20). Another calculi removal technique is to use a wire basket catheter (see Figure 17-6, B). The entire assembly of cystoscope and forceps or basket catheter are removed with the calculi, and then the cystoscope and forceps are replaced into the bladder for the next retrieval. Once the final larger calculi are removed, some smaller ones can be flushed from the bladder with a urethral catheter flush and even surgical suction. Once the calculi are removed, the cystoscope is advanced through the urethra in females and a flexible urethroscope is advanced in the urethra in males. The 2.5- to 2.8-mm flexible urethroscope can be passed from the bladder to the os penis in most dogs and through the os penis on dogs larger than 6.5 to 10 kg. It is common to see irregularly shaped calculi such that it is possible to easily pass a urethral calculi around while not feeling resistance to the passage. Urethral strictures just proximal to the os penis from prior calculi obstruction and trauma are common. Knowledge of such strictures can justify a scrotal urethrostomy (see Figure 17-10). After calculi removal and flushing, the cystotomy is closed in a single-layer, appositional suture pattern avoiding the mucosa. The greater omentum is sutured to the bladder closure.

Figure 17-20 Calculi can be removed from the bladder and urethra by either a wire basket catheter passed through the rigid cystoscope (see Figure 17-6, B) or a grasping forceps advancing parallel to the scope. The latter can be initially challenging, but practice, especially with models, quickly increases competency. Note that the relative lengths of the scope and retrieval device should be continually monitored to ensure proper orientation. To view the technique and cases demonstrating calculi removal, visit the companion website.

www.tamssmallanimalendoscopy.com

(From Rawlings CA: Endoscopic removal of urinary calculi, Compend Cont Ed Pract Vet 31(10):476-484, 2009.)

Resection of tumors, such as inflammatory polyps, can be accomplished with laparoscopic assistance. The primary modification is to extend the trocar site enough to exteriorize the bladder. The cystoscope, or even a laparoscope, can be placed into the bladder lumen to accurately define the margins of and resect an inflammatory polyp. Laparoscopy can also be used for a lymph node biopsy to stage transitional cell carcinoma.

Intraoperative Nephroscopy and Cystoscopy

Rigid endoscopy during open (or traditional) surgery can be very useful for improving visualization and surgical results. A 2.7- or 1.9-mm cystoscope or a small arthroscope can be placed into intestinal, biliary, or urogenital systems (see Figure 17-8). As compared with traditional surgery that is even supplemented with magnifying surgical loops and diode head lights, scopes provide better lighting, magnification, photographic capability, and minimal surgical insults. The optical space is obtained as for cystoscopy with the use of saline or Ringer’s solution. If hemorrhage is profuse, air or carbon dioxide can be used.

The most frequent intraoperative endoscopy is for examination of the renal pelvis and recesses when renoliths are removed. The approach is similar to arthroscopy; a scope is placed through a puncture in the greater curvature of the kidney. Penetration of the pelvis is easy because the pelvis is dilated. Calculi removal has been accomplished by placing an alligator forceps beside the 30-degree scope, an alligator forceps through a separate penetration so that triangulation can be achieved, or a basket catheter through the operating channel of the cystoscope. This use of scope and retrieval instrument within the kidney is so minimally invasive that the renal vessels do not require occlusion. The scope can also be passed through the proximal part of the ureter. When calculi are removed with a scope, the renal recesses must be thoroughly examined so that complete calculi removal is ensured. The scope can also be used to differentiate between intraluminal calculi and mural calcification. I have also used an arthroscope to examine dilated ureters when removing ureteral calculi, performing a neocystostomy, or ureterotomies. The ability to see calculi and strictures with a scope is vastly superior to other examination techniques used on the ureters. Other approaches for renal and ureteral calculi can be found in the “Minimally Invasive Options for Urinary Obstructions, Including Calculi” section.

Cystoscopes and ureteroscopes have also been useful for examination of the bladder and urethra during traditional laparotomy. The cystoscope can be passed through a minicystotomy before doing a cystotomy. An example is a small opening that will allow determination of the precise area to begin resection of an inflammatory polyp. An excellent use of a flexible urethroscope is for examination of the urethra after removal of cystic calculi during cystotomy. Urethral calculi are removed by either flushing or a basket catheter. Diagnostic accuracy and calculi removal are dramatically improved when a scope is used. In addition to clearly seeing urethral calculi, the surgeon can use the scope to see lesions, especially strictures just caudal to the os penis.

A rigid scope can also be placed into cysts, such as prostatic or paraprostatic cysts. I have used this to identify an opening from the urinary system into a recurring cyst. Endoscopic identification and closure of the opening prevented cyst recurrence.

Potential Cystoscopic Problems

Problems during transurethral cystoscopy are rare and usually reflect poor technique. For example, penetration of the urethra or other urogenital regions is due to excessive force used when the scope is advanced. The urethra in female dogs can be positioned in a tortuous fashion or can be rotated as much as 45 degrees. The vulva and vestibule change size and character during the reproductive cycles. The urethral meatus may be positioned such that the cystoscope encounters resistance when the caudal surface of the pubis provides extraluminal obstruction to the cystoscope’s entry into the urethra. Gentle and small movements, redirection or rotation of the scope, and infusion of fluids should permit urethral entry. The cystoscope should never be advanced against significant resistance.

Hemorrhage most likely develops during examination and biopsies of transitional cell carcinoma. This hemorrhage has not, in my experience, been severe enough to produce significant blood loss but may be a reason to stop the procedure. If massive flushing does not work, some clinicians use carbon dioxide or small amounts of air to provide a transient optical space.

Laparoscopic-assisted cystoscopy rarely causes problems; however, one problem is peritoneal contamination with urine if the bladder is not secured snugly against the abdominal wall. I have only seen this once, and it should not occur after an initial experience. I have had one case requiring conversion after penetration of the bladder wall when using a 5-mm laparoscopic biopsy cup forceps. Closure of the bladder wall defect was simple and probably could have been performed laparoscopically. I do not use the 5-mm biopsy forceps when obtaining a sample from the bladder wall. The most frequent complication, although still unusual, has been subcutaneous infections at the trocar site used to access the bladder.

Deciding to Convert or Discontinue Cystoscopy

I have not experienced a complication requiring conversion to traditional surgery when performing transurethral cystoscopy. Discontinuation of transurethral cystoscopy has been based on penetration of the urethra and hemorrhage that makes examination difficult. The urethra has been penetrated when a cystoscope was inappropriately forced through the wall and when a diode laser was used for resection of urethral cancer and correction of ectopic ureters. Although urethral penetration during a diode laser resection of transitional cell carcinoma is possible for any clinician, other penetrations are usually produced by improper technique and limited clinical experience. Urethral perforation has been successfully managed with a urethral catheter left in for 1 or 2 days.

Patient Care after Cystoscopy

Mild analgesic narcotic drugs are routinely provided during the first few hours after transurethral cystoscopy. If additional surgery such as resection of urethral cancer or an episioplasty is done, then longer acting and more potent narcotics are used for analgesia. Nonsteroidal drugs or tramadol can be dispensed with the patient. Most patients are discharged the day after cystoscopy, which permits in-hospital observation of urination for the first 24 hours. Some dogs can be discharged the same day. Dogs undergoing laser surgery or injection augmentation should be monitored to determine if urethral obstruction has been produced by swelling or hemorrhage. Patients with tissue resection and those with renal disease are candidates for fluid therapy at rates that are at least at maintenance levels.

Urinary tract infections should be treated with antibiotics on the basis of urine or bladder mucosal culture sensitivity testing. After a course of antibiotics has been completed, a centesis-obtained urinalysis and culture should be repeated at approximately 5 days after the last treatment.

Incontinent patients are candidates for PPA (1.5 mg/kg given three times a day) or estrogen treatment. Persistence of incontinence despite appropriate urinary tract infection control and drug treatment is a reason for surgical treatment with the use of either a colposuspension or injection augmentation.

Pain after laparoscopic-assisted cystoscopy is managed in a fashion similar to any other laparoscopic procedure. Other patient care is dependent on the animal’s disease.

Follow-Up Monitoring of Procedural Effects

Urinary tract disease is frequently progressive, persistent, or recurrent. Reasons include infection, calculi formation, incontinence, and progressive renal failure. Patients with urinary conditions must be monitored for the remainder of their lives. Recurrent infection requires that these patients be examined as frequently as every 4 months. A centesis-obtained urine sample should be cultured each time. Patients with recurrent calculi formation should have their stones chemically analyzed, and appropriate medical therapy should be instituted. In addition, imaging by survey radiography and ultrasonography should be done as frequently as every 4 months.

Interventional Radiology and Interventional Endoscopy of the Urinary Tract

Interventional endoscopy (IE) involves the use of endoscopic equipment with other contemporary imaging, such as fluoroscopy, ultrasound, or both, to perform diagnostic and therapeutic procedures. Interventional radiology (IR) uses fluoroscopy, with or without ultrasound, to access vessels and various lumens to deliver specific materials for diagnostic and therapeutic purposes (e.g., stents, chemotherapy, embolization particles, and coils). These modalities are being used in combination for endourologic procedures.

Currently, a growing investigation of the use of many novel techniques in veterinary medicine has been undertaken, and this section will discuss mainly the use of IE/IR in the management of urinary obstructions and stone disease in the upper and lower urinary tract of veterinary patients. The relatively common incidence of upper and lower urinary tract obstructions, combined with the invasiveness and morbidity associated with traditional surgical techniques, makes the use of minimally invasive procedures like IE and IR appealing. Such endourologic procedures are the standard of care in human medicine, and these procedures are currently being applied in veterinary medicine. Access and training to proper equipment and techniques are essential before many of the following procedures can be performed.

In humans, extracorporeal shock wave lithotripsy (ESWL), laser lithotripsy, ureteroscopy, ureteral stenting, and percutaneous nephrolithotomy (PCNL)/ureterolithotomy (PCNUL)/cystolithotomy (PCCL) have almost eradicated the need for open surgery in the management of stone disease.^1–7 Nephrolithiasis is a common problem in human patients, and treatment usually involves the use of ESWL (with or without concurrent ureteral stenting) or PCNL.^8–10 The decision on the modality chosen is typically based on stone size and clinician preference. Ureterolithiasis is also dealt with in a similar manner. Ureteroliths less than 5 mm have been shown to pass spontaneously in 98% of people with no intervention other than medical management alone (i.e., alpha blockade).^1–3,11,12 For stones that do not pass, ESWL has been effective for stone elimination in 50% to 81% of cases of ureteral stones, and most outcomes of success range from 50% to 67%.^13–18 Ureteroscopy, on the other hand, has a near 100% success rate when the holmium:yttrium–aluminum–garnet (YAG) laser lithotrite is used.^{10,13–15,19} This makes ureteroscopy, combined with intracorporeal lithotripsy, the first-line therapy for large ureteral calculi in humans.^{5,10,13-15,19,20} In pediatric patients, similar outcomes have been seen with ESWL and ureteroscopic lithotripsy; overall stone-free rates have been 100% with the use of holmium:YAG laser lithotripsy guided by ureteroscopy and closer to 50% to 60% with ESWL alone.^13,15,19,21 In humans, bladder and urethral stones are less of a problem than upper tract stones, contrary to that which is seen in veterinary patients. When stones are found in the bladder or urethra of humans, transurethral laser lithotripsy is the treatment of choice for stone extraction. PCCL is often the treatment of choice for large cystic stone burdens, where repetitive urethral passage and subsequent trauma are concerns.^8,22

The most common etiology of upper and lower tract urinary obstructions in veterinary patients is stone disease, but second to that is obstructive neoplasia and benign strictures. Management of urinary obstructions due to tumors and strictures is similar to that used for stone disease, which mainly involves the placement of urinary stents (urethral and ureteral).

Because of the small size of veterinary patients and the common occurrence of urinary diseases, the use of these techniques is being investigated and commonly performed by the author. Publications of the use of these modalities in small animal patients are scarce, and more are under way.^23–38 This section will discuss some additional equipment that is used for these interventional modalities that has not been previously discussed, and each area of the urinary tract will be addressed. The sections will separately expand on the current veterinary literature and procedural descriptions (Table 17-1).

Table 17-1 Procedures and Equipment for Interventional Urinary Calculi Management

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