EFFECTS OF BLADDER DISTENTION ON CANINE AND FELINE RETROGRADE URETHROGRAPHY

Retrograde urethrography with viscous contrast medium was performed in male and female dogs and cats before and after bladder distention. The viscosity of commercially prepared contrast medium was increased by addition of an aqueous lubricant. The diameter of the proximal urethra of female dogs (regions 1 and 2) was larger during urethrography (p<0.05) following bladder distention. The diameter of regions 1 and 2 of the proximal uretha of female cats in lateral recumbency was larger during urethrography (p<0.05) following bladder distention. The diameter of the distal urethra of female dogs and cats was not significantly different before or after bladder distention. The diameter of the prostatic urethra of male dogs was larger (p<0.003) following bladder distention. The diameter of the membranous and penile urethra of male dogs was not significantly different before or after urinary bladder distention. Similarly, the diameter of the urethral lumen in male cats was not significantly different before or after bladder distention. The increased viscosity of the contrast medium due to the aqueous lubricant failed to distend all areas of the male and female canine and feline urethra maximally during urethrography when the bladder was not distended. On the basis of the results of this study, the authors recommend urinary bladder distention with a lubricant-free positive contrast medium to generate intravesical hydrostatic pressure sufficient to induce urethral distention. The degree of bladder distention should be determined by digital palpation.     

Simultaneous cystometry and uroflowmetry for evaluation of micturition in two dogs

A recently developed urodynamic testing procedure was used to evaluate disorders of micturition in 2 dogs. The procedure simultaneously recorded intravesical pressure and urine flow during micturition. In an 11-year-old spayed female Sheltie that could not urinate normally, a micturition study demonstrated functional outflow obstruction of the urinary bladder. Although the urethra was patent, the urethral resistance factor, as calculated from pressure and flow data, was extremely high during voiding efforts. A urethral transitional cell carcinoma along with secondary infection, inflammation, and fibrosis were found to be responsible for the dog's problem. Ability to urinate was restored following removal of the affected portion of the urethra. In a 6-year-old spayed female Doberman Pinscher with urinary incontinence during sleep, a micturition study demonstrated urethral incompetence. During infusion of 0.9% NaCl solution into the bladder, the fluid flowed through the urethra before the detrusor muscle contracted, and urethral resistance during voiding was low. The dog's incontinence was responsive to estrogen administration.     

TRANSITIONAL CELL CARCINOMA OF THE URETHRA IN FOUR FEMALE DOGS: ITS URETHROGRAPHIC APPEARANCE

ansitional cell urethral carcinoma in four female dogs is reported. Lesion distribution in the proximal two thirds of the urethra and the radiographic appearance with retrograde positive contrast urethrography were similar in each dog. The normally smooth longitudinal urethral striations were replaced by multiple small, poorly marginated intraluminal masses that resulted in a generalized moth-eaten appearance. Extension of contrast medium into the periurethral tissues also occurred. Retrograde urethrography, a simple diagnostic technic, aided in establishing a differential diagnosis in dogs that had urine retention and stranguria.     

Colliculus seminalis as a cause of a urethral filling defect in two dogs with Sertoli cell testicular neoplasms

A urethral filling defect in the proximal portion of the pelvic urethra, suggestive of a mass, was detected by positive-contrast retrograde urethrography in 2 dogs with prostatic disease and Sertoli cell neoplasms. Extension of prostatic neoplasia into the urethra or primary urethral neoplasia were considered as explanations for the radiographic finding of an intraluminal filling defect in the pelvic urethra. Masses were visualized and biopsied during prostatic surgery. Masses were nonneoplastic and represented enlargement of the colliculus seminalis.     

Use of a self-expanding metallic stent for the treatment of a urethral stricture in a young cat

A 4-month-old intact male domestic shorthair cat was evaluated for urinary outflow obstruction after several weeks of medical management for traumatic urethral rupture. Positive-contrast retrograde urethrography and anterograde cystoscopy performed 4 weeks after the initial urethral injury confirmed a stricture approximately 1cm distal to the bladder trigone at the site of the initial urethral tear. A self-expanding metallic urethral stent (SEMS) was placed under fluoroscopic guidance to relieve the urethral stricture and re-establish luminal patency. After stent placement, the cat was able to void urine normally with minimal urinary incontinence noted. This resolved several months post-stent placement. No known clinical complications persisted other than mild intermittent hematuria.     

Urethral transitional cell carcinoma in a cat

A 15-year-old, male neutered cat was referred for investigation of dysuria. A retrograde urethrography was performed which showed two space-occupying masses within the lumen of the mid-to-proximal urethra. Exploratory coeliotomy revealed two urethral masses. Segmental urethrectomy was performed to resect the mass, and the lower urinary tract was reconstructed by vesico-urethral anastomosis. Histopathology showed the mass to be a transitional cell carcinoma with incomplete surgical margins. Tumour regrowth was suspected when dysuria was found approximately 318 days after surgery. Clinical signs were palliated by radiation using weekly fractions of 6 Gy for three weeks. The cat died of unknown causes 386 days postoperatively.     

An end‐to‐end urethral anastomosis after inguinal tunnelization: a new technique in a dog

An 8‐year‐old male dog was presented with a peri‐urethral intrapelvic mass with the characteristics of a sarcoma on computed tomography and cytology evaluation. A two‐step procedure leading to a permanent urinary diversion was performed. During the same procedure, the caudal pelvic urethra and mass were resected and an extrapelvic anastomosis of the pelvic portion of the urethra to its penile portion was performed after passage of the pelvic urethra through the inguinal canal. The procedure successfully produced a tension‐free end‐to‐end urethral anastomosis and no complications were observed during the postoperative period. Histologically, the lesion was reported as a narrowly excised liposarcoma. A 4‐week course of curative intent of radiotherapy was initiated 2 weeks after surgery. Eight months later, the dog was free of clinical signs.     

Retrograde CT urethrography using a power injector quantitatively reveals effects of bladder distension on urethral size in healthy male Beagle dogs

Quantitative analysis of the normal retrograde urethrogram is well reported in radiography, but studies on CT urethrography are lacking. Recently, a method of retrograde CT urethrography using a power injector was described. The purpose of the current, prospective, analytical study was to quantify the urethral size of five, healthy, intact, male Beagle dogs using retrograde CT urethrography and a power injector. With the injection rate of the power injector set at 0.3 mL/s, 1 mL/kg of diluted contrast medium (15 mg I/mL) was injected, and a CT examination was performed. The state of the initial urethrogram taken was defined as “empty bladder.” The same procedures were repeated with the injection of an additional 1 mL/kg of diluted contrast medium until the ureteral reflux was seen (distended bladder). There was a significant difference in volumes between the empty and distended bladder, but the membranous urethra showed the least difference (P = .0044) among the three regions (P < .0001 for the prostatic and penile urethra). Urethral diameters at six sites were measured from sagittal images, and the sites of measurements were adopted from the earlier radiographic studies. The most significant difference in the urethral diameters between the empty and distended bladder occurred at the cranial and middle prostatic urethra (P < .0001). The results of this study can be useful for interpreting the results of retrograde CT urethrography. Care must be taken when narrowing is suspected at the prostatic urethra, and if necessary, further distension of the urinary bladder should be tried.     

Transurethral resection in the management of urethral and prostatic neoplasia in 6 dogs

OBJECTIVE: To assess cystoscopic transurethral resection (TUR) for the palliative management of dogs with neoplastic infiltration of the urethra. STUDY DESIGN: Prospective clinical trial. ANIMALS: Six client-owned dogs. METHODS: Cystoscopic examination and electrosurgical TUR were performed in dogs with urination difficulties caused by prostatic or urethral neoplasia. TUR was performed in a retrograde manner in female dogs and antegrade in male dogs via exploratory celiotomy and ventral cystotomy. Cystoscopic examination was used to determine the extent of neoplastic involvement of the urethra. TUR involved piecemeal removal of neoplastic tissue from the urethral lumen using an electrocautery cutting loop. Hemorrhage was controlled with a cystoscopic cauterized roller-ball. In 2 male dogs, intraoperative radiation therapy (IORT) was used to treat both prostatic neoplasia and the sublumbar lymph node bed. Surgical technique, complications, adjuvant treatment, and outcome were recorded. RESULTS: TUR was performed in 3 male dogs with prostatic carcinoma and 2 female dogs with urethral transitional cell carcinoma (TCC). In 1 female dog, TUR was attempted but not successful because of cystoscope diameter. Iatrogenic urethral perforation occurred during TUR in 3 dogs. In 2 dogs, prolonged exposure to lavage fluid resulted in clinical and biochemical abnormalities consistent with TUR syndrome. Dysuria resolved in 5 dogs within 10 days of TUR. Treatment-related complications included urinary tract infection and tumor seeding. Local tumor progression and metastasis occurred in all dogs. CONCLUSIONS: TUR (in combination with chemotherapy+/-IORT) resulted in rapid palliation of urination difficulties in male dogs with prostatic carcinoma. In female dogs with urethral TCC, however, electrosurgical TUR cannot be recommended because of a high intra- and postoperative complication rate with no improvement in postoperative management compared with historical reports of tube cystostomy. CLINICAL RELEVANCE: TUR is a novel alternative for the palliation of male dogs with prostatic carcinoma. In female dogs with urethral TCC, electrosurgical TUR does not provide any advantages compared with tube cystostomy.     

Repair of urethral defects using fascia lata autografts in dogs

OBJECTIVE: To evaluate the feasibility of urethroplasty using a free fascia lata (FL) graft in the dog. STUDY DESIGN: In vivo experimental study. ANIMALS: Mixed-breed dogs (n=14). METHODS: Half of the circumference of the urethra, approximately 1.5 cm long, was excised in 14 male dogs to induce a urethral defect. FL (approximately 2 cm x 2 cm) harvested from the lateral thigh was sutured to the urethra using a 3-0 polyglactin 910 continuous pattern. Dogs were monitored daily for bladder distention and had urethral catheters until normal voiding was observed. On day 60, each dog had a positive contrast urethrogram, and then 8 dogs were euthanatized for gross and histologic examination. Six dogs were monitored for urologic problems for 6 months, and a positive contrast urethrogram was repeated. RESULTS: All dogs recovered successfully; 4 dogs had difficulty voiding for 2-3 days and urine was aspirated from these dogs every 3 hours until signs of painful urination disappeared. On positive contrast urethrograms, urethral anatomy was considered normal except in 4 dogs that had an irregular contour. Gross urethral examination confirmed an absence of ulceration, stricture, diverticula, or fistula formation, and the FL-lined graft survived in all dogs. No degenerative and reparative responses were observed. On histologic examination of the penile urethra, the lumen was intact, covered with transitional epithelium, and surrounded by corpus spongiosum with cavernous spaces and blood-filled vessels. CONCLUSIONS: Free FL grafts are incorporated satisfactorily and would appear to be useful for repairing urethral defects. CLINICAL RELEVANCE: FL grafts should be considered for repair of urethral defects in dogs.     

POSITIVE CONTRAST RETROGRADE URETHROGRAPHY: A USEFUL PROCEDURE FOR EVALUATING URETHRAL DISORDERS IN THE DOG

Positive contrast retrograde urethrography proved to be a useful and relatively simple technic for the evaluation of lower urinary tract disorders in the dog. The case histories of 12 dogs with such disorders were used to illustrate the role of positive contrast retrograde urethrography in the evaluation of urethral and urinary bladder integrity after caudal abdominal and pelvic trauma, and in the investigation of incontinence, stranguria, dysuria, and hematuria.     

ULTRASONOGRAPHIC APPEARANCE OF THE LOWER URINARY TRACT IN FIFTEEN NORMAL HORSES

The purpose of this study was to describe the normal ultrasonographic appearance of the caudal portion of the equine ureters, pelvic urethra, and urinary bladder and to assess ureteral contractility. Fifteen horses with no evidence of urinary tract disease (five females, five intact males and five geldings) were studied. The lower urinary tract was evaluated ultrasonographically using a transrectal approach. The normal ultrasonographic appearance and anatomic location of structures of the lower urinary tract were evaluated and anatomic relationships described. Both ureters were identified dorsal to the bladder and at their openings into the bladder. Their relationship and different appearance from the male deferent ducts/ampullae and vesicular glands was noted. Ultrasonographic measurements of the diameter of the ureters and urethra were obtained and the ureteral, urethral, and urinary bladder wall thickness recorded. The normal parameters established in this study will be useful during sonographic examination of horses with suspected urinary tract disease. Transrectal ultrasonographic examination is valuable in assessing the presence and frequency of ureteral contractions as well as in detecting structural abnormalities of the lower urinary tract. The use of high-frequency transrectal ultrasound transducers allows for excellent visualization of the structures of the equine lower urinary tract.     

Intrapelvic Urethral Anastomosis A Comparison of Three Techniques

Three intrapelvic urethral anastomosis techniques were performed on 12 mature male dogs to compare the degree of stricture. The intrapelvic urethra was transected 1 cm caudal to the prostate, and anastomosis was performed using either suturing of the urethra over an indwelling catheter, suturing of the urethra without an indwelling catheter, or apposition of the urethra without sutures over an indwelling catheter. Postoperatively, the dogs were evaluated using clinical urination patterns, biochemical tests, radiography, and pathology. Three of four suture-catheter dogs and one of four catheter-only dogs had normal urinary patterns. Stricture (25-84%) with urethral dilation or fistulas tracts was visible on retrograde, positive contrast urethrograms of 3 of 12 intact dogs 20 weeks after surgery, and on all 12 excised lower urinary tracts. Suture-catheter dogs subjectively had the least amount of stricture. All eight dogs (1 suture-catheter dog, 4 suture-only dogs, and 3 catheter-only dogs) with severe stricture (greater than 60% lumen diameter reduction) had histopathologic signs of chronic, inflammatory urinary tract disease, including four with chronic, ascending lymphocytic pyelonephritis. Hydroureter and hydronephrosis developed in two catheter-only dogs. Complete urethral transection resulted in some degree of stricture, regardless of technique used for anastomosis. Urethral anastomosis over an indwelling catheter appeared to result in a lesser degree of stricture and clinical and histopathologic derangement.     

DIMENSIONS OF THE PROSTATIC AND MEMBRANOUS URETHRA IN NORMAL MALE DOGS DURING MAXIMUM DISTENSION RETROGRADE URETHROCYSTOGRAPHY*

Prostatic and membranous urethral diameter was measured in 24 normal mature male Beagle dogs during maximum distension retrograde urethrocystography. This technique involved retrograde urethral distension by infusion with contrast medium until the urinary bladder was distended and the vesicourethral junction remained opened as observed by fluoroscopy. Lateral and ventro-dorsal radiographs were made during subsequent injections of 5–10 ml of contrast medium. The prostatic urethra was consistently greater in diameter than the membranous urethra. However, the numerical ratio between the prostatic urethral diameter and the membranous urethral diameter varied among these dogs by a factor of 2 at the numerical extremes.     

Immediate urodynamic and anatomic response to colposuspension in female Beagles

OBJECTIVE: To characterize urodynamic function and anatomy before and after colposuspension in anesthetized female Beagles. ANIMALS: 12 adult female Beagles. PROCEDURE; During general anesthesia (thiopental sodium induction and halothane maintenance), urethral pressure profiles, leak point pressure measurements with a 50-ml bladder volume, positive contrast cystograms, and retrograde vaginourethrocystograms were performed. A caudal midline laparotomy was used to perform colposuspension. Urodynamic and radiographic studies were repeated after surgery. RESULTS: Leak point pressures were increased (120 to 168.9 cm H2O), and maximum urethral closure pressures decreased (43.7 to 19.3 cm H2O ) after colposuspension. The urethra and bladder were moved cranially; the external urethral orifice was positioned closer to the pelvic cavity, and the neck of the bladder was positioned more cranially into the abdomen. Length of the urethra, as measured by use of vaginourethrocystograms, was increased by 3%. As measured by use of urethral pressure profiles, total profile length was increased by 19.9%, and functional profile length was increased by 19.2%. CONCLUSIONS AND CLINICAL RELEVANCE: Increased leak-point pressure correlated with the expected clinical improvement attributable to colposuspension. Increased exposure of the urethra to abdominal and pelvic cavity pressures may be the mechanism by which incontinent dogs become continent after colposuspension. Results of the leak-point pressure test may correlate with clinical behavior before and after colposuspension for treatment of incontinence.     

ULTRASONOGRAPHIC APPEARANCE OF URETHRAL TRANSITIONAL CELL CARCINOMA IN TEN DOGS

The mucosal margin of the urethra is best assessed by positive contrast urethrography, but ultrasonography offers complementary information such as urethral wall thickness and size of medial iliac lymph nodes. Ultrasonography of the urethra is quick, noninvasive and does not require sedation or general anesthesia. In patients with complete urethral obstruction, ultrasonography may be the only way to image the urethra. Twelve dogs which were presented to Tufts University School of Veterinary Medicine with clinical signs referable to the urinary bladder, urethra or vagina were examined ultrasonographically. Seven were neutered females and five were neutered males. Each dog had a hyperechoic, nonshadowing line at the epithelial surface of the proximal urethra. In the seven female patients and one of the males, the urethral wall was also thick and hypoechoic to surrounding tissue. In the other males, the urethral epithelial changes were at the level of the prostate, and the limits of the urethra were not visible. In six dogs, the urethral change was the only abnormality seen, while in six, bladder wall, bladder luminal and/or prostatic parenchymal changes were also detected. Three patients had hydronephrosis, and one had enlarged medial iliac lyumph nodes. Biopsies were obtained via suction with urinary catheterization (n = 6), exploratory celiotomy (n = 3), urethroscopy (n = 2), or at post-mortem (n = 1). A histopathologic diagnosis of urethral transitional cell carcinoma was obtained in ten dogs. The ultrasonographic appearance was not pathognomonic for transitional cell carcinoma, as one dog with transitional cell dysplasia and one dog with severe ulcerative and necrosupperative cystitis and urethral stricture had similar findings.     

Management of traumatic urethral rupture in 11 cats using primary alignment with a urethral catheter

OBJECTIVE: To assess the management of traumatic urethral ruptures using a systematic attempt at urethral catheterisation. METHODS: Eleven cats that had been diagnosed with a traumatic urethral rupture over a five-year period were included in this study. Rupture was assessed by positive-contrast retrograde urethrography. An attempt was made to manage these ruptures by placing an indwelling urethral catheter. RESULTS: The placement of an indwelling urethral catheter, could be performed in 10 out of 11 cats, which indicated a partial rupture. In one cat, catheterisation was not possible because of complete urethral rupture. A urethral catheter was placed into the urinary bladder via the urethra in five animals. In the other five animals, urethral catheterization required cystotomy using a modified 'inside to outside' technique. Urethral catheter removal occurred between five and 14 days after placement. Urethral healing was accomplished in all cases of catheterisation with a good outcome in eight of the 10 cats. Two cats showed clinical signs related to stricture formation during the follow-up period (seven to 72 months). Retrograde urethrography provided a definitive diagnosis of partial rupture in only six of the 10 cases of partial rupture. CLINICAL SIGNIFICANCE: Results suggested that primary alignment with the placement of a urethral catheter should be attempted for the management of traumatic urethral ruptures in cats. Gentle urethral catheterisation seems to be an effective procedure for diagnosing and dealing with partial urethral rupture in cats. Clinical stricture formation can occur, but the risk does not seem to be high. Further studies are warranted in order to define the ideal duration for maintenance of an indwelling urethral catheter in cases of traumatic partial urethral rupture.     

Traumatic urethral avulsion at the preputial fornix in a cat

A cat with pelvic fractures from being hit by a car had voided no urine in 13 hours despite iv administration of fluids. Abdominal radiography had revealed the pelvic fractures and apparently intact urinary bladder. Urine did not flow from a urethral catheter, and contrast radiography revealed the catheter to be extra-urethral within the penis. Intravenous pyelography revealed intact ureters and urinary bladder; celiotomy confirmed intact urinary bladder. Cystotomy and normograde urethral catheterization allowed localization of the ruptured urethra within the deep subcutaneous tissues of the caudal portion of the abdomen. After closure of the cystotomy and celiotomy incisions, perineal urethrostomy was performed.     

Application of preputial tube-flap urethroplasty to establish a neourethra in a male dog with complications after preputial urethrostomy

A 14-year-old male poodle weighing 7.5 kg presented due to complications after preputial urethrostomy for management of preprostatic urethral rupture. Revision surgery was performed with preputial tube-flap urethroplasty via preputiotomy. A longitudinal flap was raised from the prepuce and anastomosed to the end of the previously cut urethra to create a neourethra and reduce tension at the urethrostomy site. Follow-up retrograde positive contrast urethrography performed 10 days and 6 months postoperatively showed no contrast leakage from either the neourethra tube flap or new preputial urethrostomy. A follow-up email questionnaire, based on the American Urological Association Symptom Index, was completed by the owner 6 months after surgery. The dog had excellent symptom scores, and urinated from the prepuce without difficulty in a manner resembling physiological urination.     

Vaginourethroplasty as a salvage procedure for management of traumatic urethral rupture in a cat

This report describes a cat that suffered pelvic urethral rupture associated with multiple pelvic fractures. A vaginourethroplasty was performed as a salvage procedure, via intrapelvic anastomosis of the proximal urethra to the caudal vagina, following failure of a primary urethral anastomosis. Urinary diversion was achieved via tube cystostomy and a vagino-urethral catheter was maintained for 3 days postoperatively. Anterograde cystourethrography was performed at 7 days and 14 days postoperatively. Absence of contrast leakage from the vagino-urethral anastomosis was documented at 14 days postoperatively and the tube cystostomy was removed. An Escherichia coli urinary tract infection was treated following removal of the tube cystostomy and subsequent urine culture revealed no evidence of urinary tract infection. The cat retained normal urinary continence and elimination behaviour during the 7-month follow-up period. Vaginourethroplasty could be considered as a salvage option for management of traumatic pelvic urethral rupture in the neutered female cat.