Diagnosis and surgical management of ectopic ureters

Ureteral ectopia is a congenital abnormality of the terminal segment of one or both ureters in which the ureteral orifice is located distal to the trigone of the bladder. Continuous or intermittent urinary incontinence is the most frequently reported clinical symptom associated with ureteral ectopia. A variety of anatomic morphologies of ectopic ureters have been reported. Historically, surgical therapy focused on reestablishing drainage of the ureters into the bladder lumen. However, continued urinary incontinence after surgery is the most frequently reported complication. Specific classification and successful management of the various types of ectopic ureters remain diagnostic and therapeutic challenges to the veterinary clinician. Cystoscopic evaluation of the lower urinary tract and urodynamic evaluation of bladder and urethral function has improved the presurgical assessment of the patient. Surgical procedures, which are aimed at repositioning the ureteral orifice(s) within the bladder lumen and treating primary sphincter incompetence, are necessary to successfully manage small animal patients with ectopic ureters.     

Extramural Ectopic Ureter in a Domestic Ferret (Mustela putorius furo)

Ectopic ureter is the most common cause of congenital urinary incontinence in the dog and cat. The occurrence of ectopic ureter in the dog has been estimated to be 0.016%. A 6-month-old ferret was evaluated for urinary incontinence and urine scalding around the perineal and inguinal areas. Ultrasonography showed a nondistended urinary bladder that contained a possible intraluminal blood clot. Excretory urography revealed a left ectopic ureter. The ferret was initially treated with oral amoxicillin-clavulanate and topical silver sulfadiazine ointment for the perineal and inguinal dermatitis associated with the incontinence. Because of the potential for complications and additional surgery with ureteral transplantation, a left nephroureterectomy was performed. Surgical recovery was uneventful and the incontinence improved, although a small amount of incontinence-associated dermatitis was still present 24 days after discharge. Phenylpropanolamine therapy was initiated to address a suspected dysfunction of the urethral sphincter. Urinary incontinence improved with the phenylpropanolamine therapy; however, a small amount of incontinence persisted throughout the 3 months in which the ferret was evaluated. To the authors' knowledge, this is the first report of an ectopic ureter in a domestic ferret.     

Congenital urinary incontinence in cats: a review of 19 cases.

Nineteen cases of feline congenital urinary incontinence (10 cats with ureteral ectopia and nine with incompetence of the urethral sphincter mechanism) are reviewed. The 10 cats with ureteral ectopia are considered together with 13 from previous reports. There was no apparent breed predisposition. Most of the 23 cats were presented for urinary incontinence but two of them were continent. Thirteen were females and ectopia was unilateral in 13 and bilateral in 10. Twenty-eight of 31 ectopic ureters terminated in the urethra. The commonest complication was hydroureter/hydronephrosis (10 cases). Eighteen of the cats were treated surgically, 13 by ureteral transplantation, four by ureteronephrectomy and one by ligation of the renal blood vessels; 16 of them were cured by surgery. Congenital urethral sphincter mechanism incompetence has not been reported previously in the cat. Nine cases are presented and the urethras of all were markedly hypoplastic. A common concomitant abnormality was vaginal aplasia, with the uterine horns terminating in the dorsum of the bladder. Bacteriuria was more common in this group than in the cats with ureteral ectopia.     

Ectopic ureter in the horse: Three cases and a review of the literature

Ureterovesicular anastomosis resulted in resolution of the clinical signs of urinary incontinence in three horses with unilateral ectopic ureter. Follow-up of two of the horses ten months and three years later indicated no further urinary tract problems; the third horse died four days after surgery from intestinal infarction.

Diagnosis can be readily confirmed by antegrade or retrograde ureterography, or endoscopic visualization of the ectopic ureteral openings. Nephrectomy appears indicated in cases of unilateral ectopic ureter with associated ipsilateral urinary tract infection or hydronephrosis, providing the contralateral kidney has normal function. Ureterovesicular anastomosis appears to be indicated in the management of unilateral ectopic ureters in the absence of ascending urinary tract infection or hydronephrosis, and in cases of bilateral ectopic ureters.

     

Urethral sphincter mechanism incompetence in the male dog: importance of bladder neck position, proximal urethral length and castration

The radiographs of 37 incontinent adult male dogs with urethral sphincter mechanism incompetence were compared with those of 28 control dogs to determine if, as in the bitch, differences in bladder neck position and urethral length were implicated in the pathophysiology of urethral sphincter mechanism incompetence. Bladder neck position was significantly different; compared with continent dogs, incontinent animals were significantly more likely (P<0.005) to have intrapelvic than intra-abdominal bladder necks. However, after allowing for the influence of body size, and unlike the situation in the bitch, there was no significant difference in proximal urethral length between the two groups. Bladder neck position was significantly related to prostate size (P<0.001) and it is suggested that this is one reason why castrated male dogs are more prone to urethral sphincter mechanism incompetence than entire animals. A logistic regression analysis revealed that both bladder neck position and castration status were significant risk factors for incontinence and that they appeared to be acting independently of each other.     

Urinary incontinence due to ectopic ureter in a male dog.

Urinary incontinence was associated with an ectopic ureter in a 5-month-old, male Wire Fox Terrier. The dog regained urinary continence after transplantation of the ureter from the urethra into the urinary bladder. Of the 3 reported cases of extopic ureters in male dogs, 2 have been associated with urinary incontinence. These observations do not support the hypothesis that ectopic ureters are more frequently recognized in female than in male dogs because urinary incontinence is more commonly associated with the disorder in female dogs.     

Unusual anatomic variation of bilateral ectopic ureters in a dog

An unusual anatomic variation of bilateral ectopic ureters was diagnosed in a 6-week-old female Siberian Husky with urinary incontinence. Assessment during surgery revealed bilateral ectopic ureters with a common opening in the proximal portion of the urethra. Ureteroneocystostomy was performed bilaterally. After surgery, intermittent urinary incontinence continued, but was less severe. After resection of a persistent hymen in the 6-month-old dog, incontinence appeared to resolve, but then recurred, and has been controlled by phenylpropanolamine administration.     

Postpartum partial cystectomy through the vagina in a mare with everted partially necrotic bladder.

The bladder of a 750-kg Clydesdale mare had everted through the urethra into the vagina immediately after parturition. The bladder was reinverted into the peritoneal cavity by an attending veterinarian, but 4 days later, the bladder was everted again in the vagina. The mare was able to void urine through both ureters, which could be seen in the mucosal surface of the bladder. The everted bladder had become edematous and could not be reinverted through the urethra. A considerable portion of the fundus was necrotic. The mare was administered xylazine epidurally to induce perineal analgesia, and the necrotic portion of the bladder was resected and healthy bladder tissue was opposed with a double layer of simple continuous sutures. The urethral sphincter was longitudinally incised through the vaginal mucosa to allow reinversion of the bladder through the urethra. A purse-string suture inserted in the urethral opening decreased the urethral diameter and prevented recurrence of the condition. An inflated Foley catheter was maintained in the bladder for 5 days. The mare recovered normal urination after the catheter was removed.     

Ureteral ectopia and urethral sphincter mechanism incompetence: an update on diagnosis and management options

The two leading causes of urinary incontinence in dogs are ureteral ectopia in juveniles and urethral sphincter mechanism incompetence in adults. While the accuracy of diagnosis of ectopic ureters has improved due to increased use of CT and/or cystoscopy, the diagnosis of urethral sphincter mechanism incompetence largely remains one of exclusion. New treatment options have been developed for both conditions, which have reduced morbidity and mortality, although the rate of long‐term urinary continence has not significantly improved for either and neither has our understanding of the pathophysiology behind these failures. This review provides updates on the management of both of these conditions, with discussion of controversial areas and thoughts for future directions.     

Bilateral ectopic ureters in a male dog with unilateral renal agenesis

A 1-year-old neutered male mixed-breed dog was evaluated because of signs of urinary incontinence. Retrograde positive contrast urethrocystography and excretory urography with pneumocystography revealed bilateral intramural ectopic ureters and absence of the right kidney. During abdominal exploratory surgery, only the left kidney was located. The left intramural ectopic ureter was repaired by neoureterostomy (creation of a new opening for the ureter to enable urine to empty into the bladder). The right ectopic ureter was ligated at its entrance into the urinary bladder serosa. Results of excretory urography (performed immediately after surgery and repeated 8 weeks later) revealed successful correction of the left intramural ectopic ureter. Twelve weeks after surgery, the dog remained continent. To the authors' knowledge, there are few reports of ectopic ureters in male dogs; furthermore, the urinary tract abnormalities detected concurrently in this dog are also unusual.     

Proximal Urethral Reconstruction Using a Distally Based Ventral Bladder Tube Flap An Experimental Study

Reconstruction of the proximal urethra using a distally based tube flap mobilized from the ventral bladder wall was performed on 12 clinically normal dogs after total prostatectomy and resection of 2 cm of membranous urethra. One dog was euthanized at 6 hours and one at 36 hours after surgery because of surgical complications. Five dogs were euthanized at 10 days, two dogs at 6 weeks and three dogs at 12 weeks. Advancement of the tube flap allowed for tension-free anastomosis to the membranous urethra. Vascular integrity was maintained in all flaps. Intermittent to continuous postoperative urinary incontinence occurred in 7 of 10 dogs. The incontinence was transient in all 6 and 12 week dogs except one in which a persistent stress incontinence developed. Mild to severe dysuria was noted in 8 of 10 dogs, but was also transient in all of the 6 and 12 week dogs, with the exception of one dog. Postoperative urethral closure pressure profilometry revealed decreased tone in the membranous urethra in all 6 and 12 week dogs. It was concluded that proximal urethral reconstruction, using a ventral bladder tube flap, is a viable technique that may permit functional urodynamic recovery in dogs with significant proximal urethral loss.     

Preservation of striated-muscle urethral sphincter function with use of a surgical technique for perineal urethrostomy in cats

It has been reported that perineal urethrostomy resulted in impairment of striated-muscle urethral sphincter function in male cats, as measured by urethral pressure profilometry and electromyography (EMG). Our study was undertaken to describe and evaluate a surgical technique for perineal urethrostomy that reduces trauma to the urethral branches of the pudendal nerve. Perineal urethrostomy was performed on 10 healthy neutered cats after demonstrating that they had normal urethral sphincter function by urethral pressure profilometry (maximal urethral closure pressure [MUCP] = 151 +/- 52 cm of water) and EMG activity at the level of the striated-muscle sphincter before surgery. All cats had normal urethral sphincter function 1 week (MUCP = 194 +/- 19 cm of water, EMG activity present) and 3 weeks (MUCP greater than 200 cm of water, EMG activity present) after surgery. These results indicated that preservation of the urethral branches of the pudendal nerve during urethrostomy preserved striated-muscle urethral sphincter function.     

Urinary incontinence and incoordination in three horses associated with equine protozoal myeloencephalitis

Urinary incontinence, weakness and ataxia associated with equine protozoal myeloencephalitis (EPM) was diagnosed in three horses. Rectal examination of all horses revealed distention of the urinary bladder. Urine was expressed when manual pressure was applied to the bladder of each horse during rectal examination. The anal reflex and tone of the anus and tail were normal in all horses. Two horses had bacterial cystitis associated with Enterococcus sp. All horses were treated with pyrimethamine and a sulfonamide for EPM, but there was a variable response to treatment.     

A non-invasive technique for standing surgical repair of urinary bladder rupture in a post-partum mare: a case report

An 11-year-old mare presented 36 hours after foaling with a ruptured bladder. Uroperitoneum was diagnosed on ultrasound and from the creatinine concentration of the peritoneal fluid. Bladder endoscopy demonstrated tissue necrosis and a rent in the dorsocranial aspect of the bladder. Following stabilisation, including abdominal drainage and lavage, the mare was taken to standing surgery. Under continuous sedation and epidural anaesthesia, and after surgical preparation, a Balfour retractor was placed in the vagina. Using sterile lubricant and moderate force, it was possible to insert a hand into the bladder. The tear was easily palpable on the dorsal portion of the bladder. Two fingers were inserted through the tear and used to provide traction to evert the bladder completely into the vagina where it could grasped with the surgeons other hand to prevent further trauma. A second surgeon could then visualise the entire tear and repaired this using a single layer of size zero PDS suture in a single continuous pattern. As soon as the bladder was repaired, it was replaced via the urethra. The mare did well after surgery and was discharged after 48 hours, apparently normal.This report is the first describing repair of the bladder without an abdominal incision or incision into the urethral sphincter. This greatly reduces the chance of possible complications such as urine pooling after surgery with the previously described standing technique or bladder trauma due to traction with abdominal surgery.     

Presumptive pseudohypoaldosteronism secondary to chronic urinary tract obstruction from sloughed urinary bladder mucosa and urinary tract infection in a cat

Objective – To describe a case of presumptive secondary pseudohypoaldosteronism (PHA) in a cat with urinary tract infection and chronic urethral obstruction. The obstruction was believed to have resulted from sloughed urinary bladder mucosa secondary to pressure necrosis. Case Summary – A 5‐year‐old, 4 kg, castrated male Siamese cat presented for vomiting and stranguria. Medical history included a perineal urethrostomy for urethral obstruction. Physical examination revealed a large, painful, nonexpressible urinary bladder. Point‐of‐care testing demonstrated electrolyte derangements consistent with a postrenal azotemia and metabolic acidosis. Results of urine culture was positive for bacterial growth. Diagnostic imaging revealed presence of retroperitoneal fluid, marked urinary bladder wall thickening, bilateral hydroureter, mild bilateral pyelectasia, and small nephroliths. The patient was treated for a urinary tract obstruction and infection. In the 3 weeks following initial discharge, the patient was evaluated on multiple occasions for lethargy, intermittent vomiting, inappropriate urination, and progressive polyuria and polydipsia. Although the urinary bladder was easily expressed during repeat examinations, it was persistently distended and subjectively thickened upon palpation. Repeat ultrasound of the urinary tract showed evidence of sloughed tissue in the bladder lumen, likely secondary to chronic urethral obstruction and pressure necrosis. A cystotomy was performed to remove the necrotic tissue, and a revised perineal urethrostomy was done due to a partial urethral stricture. Bladder biopsies were obtained at this time. Postoperatively, the cat was reported by the owners to be urinating normally but continued to be polyuric and polydipsic in the week following discharge. One week after surgery, the cat presented in hypovolemic shock with laboratory findings consistent with a presumptive diagnosis of secondary PHA. New or Unique Information Provided – PHA has not been reported previously in a cat. This case report suggests that aldosterone resistance should be considered in cats with consistent laboratory findings and a history of documented obstructive uropathy and urinary tract infection.     

Treatment of urinary incontinence in dogs by endoscopic injection of Teflon

Twenty-two dogs with urethral sphincter incompetence, nonresponsive to phenylpropanolamine administration, were treated by urethral submucosal injection of Teflon. Urinary continence was achieved in all dogs for at least 2 months. Urinary incontinence recurred in 14 dogs (64%) and was controlled by a second Teflon injection in 11 of 12 dogs (92%). Minor complications included transient stranguria, with or without hematuria, after 4 of 35 injection procedures. One dog had temporary partial urethral obstruction after treatment.     

Ectopic ureters in the cat – a report of two cases

Two cases of ectopic ureters in cats are described. In both the male and the female cat urinary incontinence was the prominent feature. Diagnosis was made by excretion urography. In both cats the ectopia was bilateral. The ureters were surgically reimplanted in the bladder, which gave total relief of the incontinence. A follow–up study is described, and the results are discussed.     

Urodynamic testing in the diagnosis of small animal micturition disorders

Urodynamic testing provides a quantitative assessment of the function of the small animal lower urinary tract. Most commonly these techniques are utilized to assess urethral tone (urethral pressure profile or UPP) and bladder detrusor muscle function (cystometrogram or CMG). A UPP may be indicated in cases of canine and feline micturition disorders. Examples include suspected primary sphincter mechanism incontinence (PSMI), ureteral ectopia, other congenital abnormalities, suspected neurological disorders, and mechanical or functional urethral obstruction. A UPP can be performed effectively utilizing human dedicated equipment. A CMG may be indicated to assess detrusor function in all of the above cases as well as cases of suspected atonic or infiltrated urinary bladder. This procedure can also be performed using the same human equipment. These tests are useful not only in providing an accurate diagnosis, but also in providing a sensitive prognostic indicator for clinical outcome of micturition disorders with and without pharmacological or surgical therapy. A leak pressure point may also be established in dogs with urinary incontinence, and may be even more sensitive than a UPP to predict clinical incontinence in some cases.     

Surgical Treatment of Male Dogs With Urinary Incontinence Due to Urethral Sphincter Mechanism Incompetence

A modified technique for fixation of the deferent ducts to the abdominal wall as a therapy for urinary incontinence caused by urethral sphincter mechanism incompetence (USMI) in male dogs is described, and the results in seven dogs are reported. The goal of this treatment was to achieve an effect similar to colposuspension in female dogs with USMI. An increase in urethral length of an average of 28 mm was obtained (range, 5 to 50 mm, measured radiographically). Preoperatively, the neck of the bladder was located intrapelvically in five of seven dogs. Postoperatively, the neck of the bladder was located intra-abdominally, near the caudo-ventral abdominal wall, in all dogs. After a follow-up period of 12 to 49 months, the response to surgery, based on lack of or decrease of incontinence, was excellent in three dogs, good in another three, and poor in one dog.