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.     

A technique for resection of invasive tumors involving the trigone area of the bladder in dogs: preliminary results in two dogs

Objective— To describe a surgical technique for resection of the entire bladder neck, including the trigone and proximal urethra in dogs with invasive tumors causing life-threatening urinary tract obstruction.
Study Design— Clinical case reports.
Animals— Dogs (n=2) with bladder tumors.
Methods— Circumferential excision of the bladder neck and proximal urethra with preservation of the neurovascular pedicles was performed to remove a rhabdomyosarcoma (dog 1) and a transitional cell carcinoma (dog 2) involving the trigone and bladder neck that were causing urinary tract obstruction. Reconstruction of the bladder and proximal urethra included bilateral ureteroneocystostomy. Adjuvant chemotherapy was administered postoperatively to both dogs.
Results— Postoperatively, dogs 1 and 2 were continent after 7 and 17 days, respectively, and regained normal urinary function after resolution of a transient pollakiuria. Dog 1 had no evidence of local or regional recurrence; however, a large solitary pulmonary metastatic lesion was diagnosed 8 months later. The dog was euthanatized despite a lack of clinical signs. Dog 2 had at least 1 metastatic lesion in the abdominal wall 6 months later and was euthanatized at 580 days because of renal failure.
Conclusion— En-bloc removal of the bladder neck and proximal urethra with preservation of the dorsal vascular and nervous pedicles, although a technically challenging procedure, can be performed without associated urinary incontinence or bladder wall necrosis.
Clinical Relevance— In dogs with invasive bladder tumors causing life-threatening urinary tract obstruction, resection of the bladder neck and proximal urethra should be considered as a promising surgical alternative to urinary diversion.     

Evaluation of palliative stenting for management of malignant urethral obstructions in dogs

OBJECTIVE: To evaluate use of balloon-expandable and self-expanding metallic stents in management of malignant urethral obstructions in dogs. DESIGN: Original study. ANIMALS: 12 dogs with malignant urethral obstructions. PROCEDURES: The extent and location of urethral obstructions and the diameter of adjacent unaffected luminal segments were determined by use of fluoroscopically guided wires and measuring catheters. Stents were chosen to extend approximately 1 cm proximal and distal to the obstruction. Stent diameters were chosen to be approximately 10% greater than the diameter of healthy portions of the urethra to prevent displacement. Stents were placed in the urethra under fluoroscopic guidance to restore luminal patency. RESULTS: 3 dogs received balloon-expandable metallic stents, and 9 dogs received self-expanding metallic stents. The placement procedures were rapid, safe, and effective at restoring luminal patency and were not associated with major complications. Complications included recurrent urethral obstruction secondary to blood clot formation and urethral edema in 1 dog and stent dislodgement into the urinary bladder in 1 dog. All dogs were able to urinate immediately after the procedure. Nine dogs (3/4 females and 6/8 males) were continent or mildly incontinent after stent placement. Of the remaining 3 dogs, 2 developed severe incontinence and 1 had an atonic bladder. Seven dogs were considered to have good to excellent outcome, 3 had fair outcome, and 2 had poor outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Transurethral placement of metallic stents was a safe and effective palliative treatment option for dogs with malignant urethral obstructions.     

Urethral conformation and position in relation to urinary incontinence in the bitch.

The conformation of the urethra, the position of the bladder neck and the distance between the external urethral orifice and the cranial pubic brim were compared in 30 continent and 30 incontinent bitches with incompetence of the urethral sphincter mechanism, using the measurements made from vagino-urethrograms. The bladder neck was significantly (P less than 0.001) further caudal in incontinent dogs than in continent dogs. Its position was not affected by neutering and could not be explained by the degree of urethral curvature. The distance from the external urethral orifice to the cranial pubic brim was correlated (P less than 0.001) with bodyweight but was not significantly different in the continent and incontinent bitches. In neutered animals, the distance between the cranial pubic brim and the external urethral orifice was significantly (P less than 0.05) shorter than in entire animals.     

Use of cystoscopic-guided laser ablation for treatment of intramural ureteral ectopia in male dogs: four cases (2006-2007)

OBJECTIVE: To describe and evaluate the outcome of cystoscopic-guided laser ablation of intramural ureteral ectopia in male dogs. DESIGN: Retrospective case series. ANIMALS: 4 incontinent male dogs with intramural ureteral ectopia. PROCEDURES: Intramural ectopic ureters were diagnosed via preoperative computed tomography-IV urography and subsequent cystoscopy. Transurethral cystoscopic-guided laser ablation (diode laser [n = 3 dogs] and holmium:yttrium aluminum garnet laser [1]) was performed to proximally relocate the ectopic ureteral orifice to the urinary bladder. Fluoroscopy was used during the procedures to confirm that the ureteral tract was intramural and the ureteral orifice was intravesicular after the procedure. In 1 dog with bilateral ureteral ectopia, staged laser ablation was performed at 6-week intervals because of difficulty viewing the second ureter on the first attempt. All ureteral orifices were initially located in the middle to proximal portion of the prostatic portion of the urethra. Six weeks after surgery, imaging was repeated in 3 of 4 dogs. RESULTS: Postoperative dysuria or hematuria did not develop. All dogs were immediately continent after laser treatment and remained so at a median follow-up period of 18 months (range, 15 to 20 months) without medical management. Conclusions and CLINICAL RELEVANCE: Ureteral ectopia can cause urinary incontinence in male dogs and is usually associated with other urinary tract abnormalities. Cystoscopic-guided laser ablation provided an effective and minimally invasive alternative to surgical management of intramural ureteral ectopia.     

Transobturator vaginal tape inside out for treatment of urethral sphincter mechanism incompetence: preliminary results in 7 female dogs

Objectives: To evaluate the clinical efficacy of the transobturator vaginal tape inside‐out (TVT‐O) in incontinent female dogs affected with urethral sphincter mechanism incompetence (USMI) and to determine its urodynamic and morphologic effects. Study Design: Case series. Animals: Incontinent spayed female dogs (n=7). Methods: TVT‐O tape was inserted in 7 incontinent female dogs diagnosed with USMI. Urethral pressure profilometry (UPP) and vaginourethrograms were performed preoperatively, and 1 and 3 months postoperatively. Clinical efficacy of the technique was evaluated and complications reported. Follow‐up information was evaluated by a telephone questionnaire. Results: All dogs were continent immediately after the procedure. Incontinence recurred 2 months after surgery in 1 dog and was treated by phenylpropanolamine administration. At mean follow‐up time of 11.3 months, 6 of 7 dogs were continent. An iatrogenic urethral tear occurred intraoperatively in 1 dog. No postoperative complications were encountered. The postoperative UPPs showed significantly increased maximal urethral closure pressure and integrated pressure. Postoperative vaginourethrograms were unremarkable. The surgical procedure did not modify the location of the urinary bladder neck in dogs with a “pelvic urinary bladder” preoperatively. Conclusions: TVT‐O was efficient in maintaining short term continence in 6 of 7 dogs affected with USMI.     

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.     

Ureterocolonlc Anastomosis in Ten Dogs with Transitional Cell Carcinoma

Ureterocolonic anastomosis (UCA) was performed in 10 dogs with transitional cell carcinoma of the urinary bladder trigone or the urethra, or both. All grossly visible tumor was excised. All of the dogs recovered from anesthesia and surgery and had anal continence with no urine leakage. One dog died of undetermined causes 7 days after surgery. Nine dogs survived 1 to 5 months. The owners of eight of the dogs considered their dog's quality of life to be acceptable. Four dogs were euthanatized because of neurologic disease, three of which also had nausea and vomiting. The neurologic and gastrointestinal signs may have been caused by hyperammonemia, metabolic acidosis, and uremia. Blood ammonia levels were elevated in two dogs with neurologic signs. Hyperchloremic metabolic acidosis that was reversible with bicarbonate therapy was diagnosed in five dogs. All of the dogs were azotemic because of intestinal recycling of urea. Serum creatinine concentrations increased in four dogs after surgery. Drug-induced renal disease may have developed in two dogs. Pyelonephritis developed in five kidneys, two of which had outflow obstruction and two had bilateral hydroureteronephrosis before the UCA. In this small number of dogs, surgical excision of transitional cell carcinoma was not curative with six dogs having confirmed metastatic lesions at the time of death.     

Evaluation of long-term effects of endoscopic injection of collagen into the urethral submucosa for treatment of urethral sphincter incompetence in female dogs: 40 cases (1993-2000)

OBJECTIVE: To evaluate long-term success of endoscopic injection of collagen into the urethral submucosa in female dogs with urinary incontinence caused by urethral sphincter incompetence. DESIGN: Retrospective study. ANIMALS: 40 incontinent female dogs. PROCEDURE: Medical records were reviewed for outcome and other results for dogs in which a cystoscope was passed into the urethra for deposition of 3 collagen deposits into the submucosa. RESULTS: 27 (68%) dogs were continent for 1 to 64 months (mean, 17 months) after the collagen injection. In another 10 dogs, incontinence improved and in 6 of these dogs, full continence was regained with administration of additional medication. In 3 dogs, incontinence was unchanged. As long as 12 months after injection, there was a deterioration in the initial result in 16 dogs, after which their condition stabilized. Mild and transient adverse effects developed in 6 (15%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Long-term success of endoscopic injection of collagen was satisfactory. Relapse of incontinence might be caused by flattening of the collagen deposits rather than resorption of the collagen.     

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.     

Modified "cup-patch" ileocystoplasty for urinary bladder reconstruction in a dog

Full-thickness wall necrosis involving 90 to 95% of the urinary bladder was diagnosed in a 6-month-old Golden Retriever 2 days after ovariohysterectomy. An isolated, vascularized segment of ileum denuded of mucosa was used to reconstruct the urinary bladder. Serial excretory urography over 1 year indicated gradual enlargement of the bladder, with development of a smooth mucosal surface. At 6 months after reconstructive surgery, the dog was voiding urine 2 to 3 times/d and was continent. Results of renal function testing, urinalysis, and bacteriologic culture of urine were all considered normal on follow-up examinations. The cause of bladder wall necrosis was never determined. Ileocystoplasty as described herein appears to be an effective urinary bladder reconstructive procedure in dogs whenever the bladder neck, proximal portion of the urethra, and their neurovascular supply can be spared.     

Prostatopexy as a treatment for urethral sphincter mechanism incompetence in male dogs

OBJECTIVES: The incidence of urinary incontinence due to urethral sphincter mechanism incompetence (USMI) in male dogs is relatively rare compared with the incidence in bitches, but the medical management of USMI in male dogs is less rewarding than in bitches. Attempts have been made to manage this condition surgically using either urethral bulking agents such as Teflon or by relocating the intrapelvic bladder neck to an intra-abdominal position by vas deferentopexy. This paper reports the response to prostatopexy in male dogs with USMI. METHODS: The response to prostatopexy was determined in nine severely incontinent male dogs with USMI that were followed up for periods ranging from 10 months to five years (mean 2.3 years). RESULTS: One dog was cured, four were improved, and no improvement in the frequency or degree of urinary incontinence occurred in the remaining four animals. No complications were seen in any of the dogs. CLINICAL SIGNIFICANCE: Prostatopexy may provide a further method of treating male dogs with USMI that do not respond to medical therapy.     

Primary prostatic haemangiosarcoma causing severe haematuria in a dog

A 10-year-old, entire, male, mixed-breed dog was presented for severe haematuria and stranguria. Ultrasound revealed a large intraluminal urinary bladder blood clot and a prostatic space-occupying lesion. Invasion of the lesion into the prostatic urethra was detected ultrasonographically during compression of the urinary bladder. Post-mortem examination revealed primary prostatic haemangiosarcoma infiltrating the urethra. Haemangiosarcoma should be considered as a rare cause of prostatic mass lesions, haematuria or lower urinary tract signs in dogs.     

Ischial ostectomy in direct end-to-end anastomosis of the pelvic urethra in male dogs

Ischial ostectomy in conjunction with direct end-to-end anastomosis of the pelvic urethra was performed after prostatectomy in cadavers of 10 male dogs with normal bladder and urethra, and in a mongrel dog with an enlarged prostrate and transection injury of the pelvic urethra. In the cadavers, tension on the suture line was assessed from the intravesical pressure (IVP) and volume of normal saline solution (NSS) instilled into the bladder to cause dehiscence of the anastomosis before and after the ostectomy. The experiment found that the IVP and instilled NSS volume after the ischial ostectomy were significantly (p<0.01) higher than those before the ostectomy, suggesting the ostectomy can reduce tension on the suture line and risk of dehiscence. Clinically, the dog had uneventful recovery with normal urination. Fluoroscopic examination of the caudal abdomen at 3 and 16weeks after surgery revealed urethral continuity without perforation and narrowing of the anastomosis site.     

Use of laparoscopic-assisted cystoscopy for removal of urinary calculi in dogs

Urinary calculi were removed by means of laparoscopic-assisted cystoscopy in 3 dogs. Two small abdominal incisions were made--1 for a laparoscope and 1 for placement of a Babcock forceps to aid in grasping and lifting the urinary bladder to the abdominal wall. A cystoscope and instruments for calculi removal were passed through a small cystotomy. Biopsy of the urinary bladder or other abdominal organs could also be performed by use of this technique. Laparoscopic-assisted cystoscopy was minimally invasive and provided clear images of the mucosal surface of the urinary bladder and proximal portion of the urethra for easy retrieval of urinary calculi. An imaging procedure should be performed to ensure complete removal of calculi.     

Bladder retroflexion in the dog

In a series of 61 dogs examined for perineal hernia 12, (20 per cent) were found to have bladder retroflexion. Associated urinary signs were seen in only five dogs including one case with bladder rupture. Radiology was found to be the most consistently accurate means of diagnosis. Bladders were drained by catheterization, or by percutaneous or surgical cystocentesis before manipulative or surgical reduction. Conventional herniorrhaphy and castration were performed in all cases. Cystopexy was performed in only one case although recurrence of the retroflexion was not encountered in any dogs. Three dogs remained urinary incontinent after treatment.     

Partial cystectomy for urinary bladder neoplasia: surgical technique and outcome in 11 dogs

Partial cystectomy was performed in 11 dogs with bladder neoplasia (10 with transitional cell carcinoma and one with rhabdomyosarcoma). Between 40 and 70 per cent of the bladder was excised during the partial cystectomies. In eight dogs, all the grossly visible tumour was excised but on histopathological examination of the excised tissue, neoplastic tissue was found to extend to the surgical margins in four of these dogs. A ureteral stoma was excised with the tumour in four dogs necessitating ureteral reimplantation; one dog had both ureteral stomas excised and bilateral ureteral reimplantation. The bladder incision dehisced in two dogs, necessitating a second surgery. Six dogs were polla-kiuric after surgery. Pollakiuria resolved within two months in four dogs and persisted in two dogs. None was incontinent. Local tumour recurrence was suspected in nine dogs based on imaging studies and confirmed in five dogs during post mortem examination. Five dogs were euthanased two to seven months after surgery. Six dogs survived at least one year, two of these dogs remain alive at 17 and 27 months after surgery. It is concluded that partial cystectomy may provide local control of bladder neoplasia.     

Use of Electrohydraulic Lithotripsy in 28 Dogs with Bladder and Urethral Calculi

Background: Electrohydraulic lithotripsy (EHL) has been used as an alternative to cystotomy in human medicine to remove urinary calculi. This prospective study evaluated the efficacy and safety of EHL to remove urinary calculi in dogs. Hypothesis: EHL is an efficient and safe method of treatment of bladder and urethral calculi in dogs. Methods: Dogs presented between January 1, 2005 and June 1, 2007 with lower urinary tract calculi diagnosed by radiographs or ultrasound examination were included in the study. Physical examination, CBC, biochemistry, urinalysis, and urine culture were performed at presentation. EHL and voiding urohydropulsion were performed under general anesthesia. Patients received IV fluids for 12 hours after which they were rechecked by ultrasound examination and discharged with antibiotics and anti‐inflammatory drugs for 5 days. All patients were reevaluated 1, 3, and 6 months after presentation by physical examination, urinalysis, and ultrasonography. Results: Twenty‐eight dogs (19 males, 9 females) presented with bladder or urethral calculi or both underwent lithotripsy. Their median weight was 8.3 kg. Calcium oxalate calculi were present in 22 dogs, struvite in 4, and mixed calculi in 2. Fragmentation was done in the bladder (23 dogs) and in the urethra (12 dogs). Calculus‐free rate was higher for urethral than for bladder calculi in males and higher for bladder calculi in females than in males. No major complications were reported. Twelve dogs relapsed within 6 months. Conclusions: Results of this study support the use of EHL as a minimally invasive treatment for bladder calculi in females and for urethral calculi in male dogs.     

Evaluation of a Transpelvic Sling Procedure With and Without Colposuspension for Treatment of Female Dogs With Refractory Urethral Sphincter Mechanism Incompetence

Objective —To evaluate a sling procedure using a polyester ribbon passed through the obturator foramen, around the urethra, and fixed outside the pelvis for the treatment of female dogs with refractory urethral sphincter mechanism incompetence (USMI). Animals —26 female dogs with USMI that had not improved with medical management. Methods—All dogs underwent a transpelvic sling procedure, and in 13, with a radiographic diagnosis of a pelvic bladder, additional colposuspension was performed. Multichannel urethral pressure profilometry (UPP) and diuresis cystourethrometry (UCM) were performed in all dogs before and in seven dogs 2 to 14 months after surgery. Long-term results of surgery and medical therapy were determined. Results — 13 dogs (50%), 6 of these without additional colposuspension, were continent after surgery and remained continent during a follow-up period of 12 to 36 months (mean, 19 months). Seven, three of which had colposuspension, had improved markedly. Four of these dogs became continent with additional medical therapy. Five dogs did not improve, and three of these were eventually euthanatized. In one dog, the sling was removed after 5 days because of persistent stranguria. Surgery and medical therapy together resulted in continence in 17 dogs (65%) during a follow-up period of 6 to 36 months (mean, 22 months). Postoperative dysuria or stranguria occurred in six dogs, and four of these underwent a colposuspension procedure. Two dogs developed a fistula, 2 and 3 years after surgery. Preoperatively, decreased urethral resistance was suggested by the findings of UPP and UCM in 25 dogs, and an abnormally high compliance was found in 3, detrusor instability in 2, and a low threshold pressure in 1 dog. There was no apparent correlation between these findings and the outcome of surgery. Urethral closure pressures measured after surgery were significantly increased but were still lower than the normal range in all dogs with persistent or recurrent incontinence. Conclusions —A transpelvic sling procedure, with or without additional colposuspension, can be useful in the management of dogs with refractory urinary incontinence. The procedure is not beneficial if it does not increase urethral pressure close to, or within, the normal range.     

Urinary Incontinence after Prostatectomy in Dogs

Eleven dogs with prostatic disease were treated by total prostatectomy. Urinary incontinence persisted in three of nine dogs, two of which were also incontinent before surgery. The incidence of postoperative incontinence may be reduced by undermining the prostatic capsule to preserve as much prostatic urethra as possible. The risk of postoperative incontinence appeared greater if there was prostatic neoplasia or preoperative urinary incontinence.