Feline Perineal Urethrostomy: A Review of Past and Present Literature

Urethral obstruction is a potentially fatal condition and in cases of recurrent obstruction or an identified cause that is refractory to medical management, a urethrostomy may be performed for definitive treatment. Perineal urethrostomy is the surgical creation of a permanent stoma in the wider pelvic urethra via anastomosis to the perineal skin. Diagnosis of the underlying cause of obstruction, proper perioperative treatment, and an understanding of the anatomy and surgical technique, are imperative to the success of this procedure. This review intends to highlight these aspects, as well as the common complications and expected prognosis to aid decision making in the management of these cases.     

Penile amputation and scrotal urethrostomy in 18 dogs

The objective of this study was to report the signalment, indications for surgery, postoperative complications and outcome in dogs undergoing penile amputation and scrotal urethrostomy. Medical records of three surgical referral facilities were reviewed for dogs undergoing penile amputation and scrotal urethrostomy between January 2003 and July 2010. Data collected included signalment, presenting signs, indication for penile amputation, surgical technique, postoperative complications and long-term outcome. Eighteen dogs were included in the study. Indications for surgery were treatment of neoplasia (n=6), external or unknown penile trauma (n=4), penile trauma or necrosis associated with urethral obstruction with calculi (n=3), priapism (n=4) and balanoposthitis (n=1). All dogs suffered mild postoperative haemorrhage (posturination and/or spontaneous) from the urethrostomy stoma for up to 21 days (mean 5.5 days). Four dogs had minor complications recorded at suture removal (minor dehiscence (n=1), mild bruising and swelling around the urethrostomy site and mild haemorrhage at suture removal (n=2), and granulation at the edge of stoma (n=1)). One dog had a major complication (wound dehiscence and subsequent stricture of the stoma). Long-term outcome was excellent in all dogs with non-neoplastic disease. Local tumour recurrence and/or metastatic disease occurred within five to 12 months of surgery in two dogs undergoing penile amputation for the treatment of neoplasia. Both dogs were euthanased.     

Transpelvic urethrostomy in 11 cats using an ischial ostectomy

OBJECTIVE: To investigate the feasibility and long-term outcome of a modified subpubic urethrostomy technique termed transpelvic urethrostomy (TPU) in cats. STUDY DESIGN: Prospective clinical study. ANIMALS: Eleven male cats with obstructive lower urinary tract disease that could not be relieved, and requiring a surgical urinary diversion, were selected for TPU. METHODS: With the cat in dorsal recumbency, the penis was exposed and the ventral pelvis was denuded by median adductor muscle elevation. An approximately 12 mm x 15 mm area of ischium was removed. The pelvic urethra, 8-20 mm cranial to the bulbourethral glands, was incised longitudinally and sutured to the skin to create a urethrostomy. RESULTS: All cats were neutered males (2-9 years); none were uremic or hyperkalemic at admission. Urine was cultured if there was leukocyturia, nitrituria, and/or bacteriua. Bacteria were isolated from 2 specimens. A patent urethrostomy was created in all cats without operative complications. Except for 1 cat without associated clinical signs, stricture was not evident between 9 and 42 months after urethrostomy. One cat had postoperative urinary incontinence (UI) that resolved within 4 weeks. Two cats each had 1 episode of idiopathic lower urinary tract disease after 6-month follow-up; both responded to medical therapy. CONCLUSIONS: TPU was used as a successful urinary diversion procedure relieving signs of urinary tract obstruction and preventing further obstruction, with few complications. The incidence of UI after TPU remains minimal. CLINICAL RELEVANCE: TPU should be considered as a salvage urinary diversion procedure in cats (as an alternative to prepubic and subpubic techniques). TPU may also be considered as a possible primary urinary diversion solution (an alternative to perineal urethrostomy) for obstructive lower urinary tract disease in cats.     

Urethrotomy and urethrostomy in the dog

An incision, or urethrotomy, is made into the urethral lumen to remove or relieve an obstruction temporarily. When permanent diversion of urine flow proximal to an obstructed, severely damaged, or diseased urethra is required, a urethrostomy is performed. Urethrostomy is also performed to diminish the risk of urethral obstruction due to recurrent urinary calculi that are not likely to be resolved with medical therapy. Whenever possible, to reduce the risk of urethral stricture or recurrent urinary tract infection, urethral surgery is avoided when an obstruction can be relieved by retrohydropropulsion or catheterization. Urethrotomy can be performed in the prescrotal or perineal regions depending on the level of the urethral obstruction. Although urethrostomy can be made in the perineal and antepubic positions, scrotal urethrostomy is the procedure of choice provided the lesion is distal to this area. Specific urethrotomy and urethrostomy procedures are described, including discussion about selection of the appropriate procedure for the urethral problem, patient stabilization considerations, general postoperative management, and risk of complications.     

Prevalence of bacterial urinary tract infection after perineal urethrostomy in cats.

It has been reported that the prevalence of bacterial urinary tract infection (UTI) increases after perineal urethrostomy in male cats. Perineal urethrostomy, using a surgical technique preserving striated urethral sphincter function, was performed on 2 groups of cats. The first group consisted of healthy castrated cats. The second group of cats had recurrent or persistent urethral obstruction. All cats had normal urethral sphincter function after surgery, as measured by urethral pressure profilometry and electromyography. Long-term periodic urinalysis and bacterial culturing of urine was performed on all cats. Twenty-two percent of the previously obstructed cats had recurrent bacterial UTI, compared with none of the healthy cats. On the basis of these findings, we suggest that perineal urethrostomy per se does not predispose cats to bacterial UTI, but surgical alteration of the urethral meatus combined with an underlying uropathy may increase the prevalence of ascending bacterial UTI after surgery.     

Suture-related urolithiasis following repair of inadvertent prostatectomy in a dog

A 10-month-old male chow chow mixed breed dog was presented for anuria secondary to inadvertent prostatectomy performed during unilateral cryptorchidectomy. Surgical repair was successfully performed; however, this resulted in suture-associated urolith formation 3 months later, requiring a second surgical intervention and urethrostomy.     

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.     

Use of fluoroscopically guided percutaneous antegrade urethral catheterization for the treatment of urethral obstruction in male cats: 9 cases (2000-2009)

Objective-To describe the technique and determine outcome for male cats with urethral obstruction treated with fluoroscopically guided percutaneous antegrade urethral catheterization (PAUC). Design-Retrospective case series. Animals-9 client-owned neutered male cats with urethral obstruction and inability to pass a retrograde urinary catheter. Procedures-Information regarding the procedure and hospitalization was obtained from medical records. Long-term follow-up was obtained via medical record review or telephone interview. Results-Diagnoses included iatrogenic urethral tear (n = 6), obstructive urethral calculi (1), urethral ulceration (1), and urethral stricture (1). Seven of the 9 procedures were successful. The 2 patients in which PAUC failed had mechanical obstructions preventing guide wire access across the urethral obstruction. Procedure times ranged from 25 to 120 minutes. No complications were noted in any patients during the procedure. One patient was euthanized because of unrelated disease. Follow-up information was available for 6 of 8 surviving patients. No complications that could be directly attributed to the procedure were noted. All 6 patients had a perineal urethrostomy performed 0 days to 6 weeks following the procedure because of reobstruction of the lower urinary tract. None of these patients had documented urethral strictures and none had recurrence of clinical signs following perineal urethrostomy. Conclusions and Clinical Relevance-Results suggested that PAUC can be a simple, rapid, minimally invasive, and safe technique to facilitate transurethral catheterization in select cases. Patients with iatrogenic urethral tears may be good candidates. Patients with impacted urethral calculi, severe strictures or ulcerations, or a nondistended urinary bladder may be less amenable to PAUC.     

Hypospadias in a polar bear (Ursus maritimus).

Corrective surgery on a 1.5-yr-old male polar bear (Ursus maritimus) with hypospadias included amputation of the vestigial penis, bilateral orchiectomy with scrotal ablation, and distal perineal urethrostomy. Hypospadias in other species is a congenital deformity that may be caused by extra- and intrauterine factors resulting in a disruption of the testosterone balance during urethral development, but the causative mechanism in this bear is unknown. The urethrostomy site was functional without complications 8 mo after surgery.     

Urethral Defects in Geldings With Hematuria and Stallions With Hemospermia

A urethral defect, presumed to communicate with the corpus spongiosum penis, caused hematuria in seven geldings and hemospermia in three stallions. Hematuria in geldings occurred at the end of urination. Hematuria was not observed in stallions with hemospermia. A linear urethral defect was identified, by endoscopic examination, on the convex surface the urethra at the level of the ischial arch of each horse. Cause of the defect was not determined. Two stallions were successfully treated for hemospermia, one by temporary subischial urethrostomy combined with sexual rest for 10 weeks, and the other by sexual rest alone for 6 months. The third stallion had hemospermia 6 weeks after urethrostomy. The geldings were successfully treated for hematuria, six by temporary subischial urethrostomy, and one by a subischial incision that extended into the corpus spongiosum penis but did not enter the lumen of the urethra. Efficacy of subischial urethrostomy for treatment of hemospermia was difficult to assess because of the small number of surgically treated stallions. In geldings, surgery eliminated hematuria, presumably by reducing vascular pressure in the corpus spongiosum penis during urination, thus allowing the urethral defect to heal.     

Squamous cell carcinoma of the equine external genitalia: a review and assessment of penile amputation and urethrostomy as a surgical treatment

A retrospective analysis was performed on 48 cases of suspected neoplasia involving the equine external genitalia. Forty nine squamous cell carcinomata (SCC) and 23 squamous papillomata (SP) were identified. Two cases of epithelial hyperplasia and one case of habronemiasis were also recognised histopathologically. The glans penis was the most common site of tumour development accounting for 53 per cent of cases of SCC and 61 per cent of SP. The urethral diverticulum, urethral process or urethra was involved in 27.6 per cent (8/29) of cases of SCC. Twelve per cent (5/41) of cases of SCC were confirmed to have metastatic involvement of the local lymph nodes. Papillomata showing pre-malignant changes were identified in five cases. Seventy five per cent (36/48) of the animals presented were ponies. All were geldings, mean age 16.5 years. Penile amputation and urethrostomy, preputial ablation and proximal urethrostomy or local excision were used in the surgical management of these animals; three cases were inoperable and destroyed at presentation. Oedema, haemorrhage and stenosis of the urethrostomy site were encountered as post operative complications. Sixty six per cent (6/9) of animals with SCC of the glans penis (without urethral involvement), which had a known history over the follow up period, treated by penile amputation and urethrostomy survived for longer than 18 months. Similarly, of those with urethral involvement only 28.6 per cent (2/7) survived for a similar follow-up period. SCC not uncommonly affects the external genitalia of aged pony geldings and frequently the glans penis. If the lesion is identified before local metastasis occurs, penile amputation and urethrostomy is indicated and the prognosis is favourable.     

Perineal urethrostomy in a brown capuchin monkey (Cebus apella).

A 14-yr-old male brown capuchin monkey (Cebus apella) was presented to the Veterinary Teaching Hospital of the Hebrew University of Jerusalem, Israel, with stranguria. The history included distal urethral obstruction and a previous surgical attempt to create a urinary diversion through the perineum. A perineal urethrostomy was performed. In a 17-mo follow-up period, neither stranguria nor dysuria was observed, and the monkey's social behavior appeared normal. Perineal urethrostomy appears to be a simple and practical procedure in primates with a compromised distal urethra.     

Prepubic urethrostomy: A long-term study in 16 cats

OBJECTIVE: To investigate the indications for and long-term outcome of prepubic urethrostomy (PPU) in the cat. STUDY DESIGN: Retrospective survey. ANIMALS: Sixteen cats that had undergone PPU. METHODS: Data were recovered from the medical records of the cats. Follow-up information was obtained from the owners and referring veterinarians. RESULTS: Indications for PPU were: failed perineal urethrostomy for the management of idiopathic lower urinary tract disease (ILUTD) (8 cats) or urethral trauma (1 cat); unresolved pelvic urethral obstruction after recurrent ILUTD (5 cats); and stenosis of the pelvic urethra as a result of trauma (2 cats). A patent urethral stoma was created in all cases. Signs of lower urinary tract disease were present in 8 cats postoperatively. With appropriate dietary management, these signs resolved in 2 cats and improved in another 4 cats. Eleven cats experienced postoperative complications that consisted of peristomal skin irritation or necrosis (7 cats) and urinary incontinence (6 cats). Complications developed in the immediate postoperative period in 6 cats, and resolved in 2 of these. Six cats developed late complications, at 6 to 84 months postoperatively. Six cats were euthanatized between 1 and 26 months' postoperatively. The mean survival time in these cats was 13 months. Reasons for euthanasia included urinary incontinence (3 cats), skin necrosis (2 cats), and unresolvable ILUTD (1 cat). CONCLUSIONS: PPU is a salvage procedure that is successful in relieving the signs of urinary tract obstruction and preventing further obstruction. However, potential complications should limit its use to cases in which standard techniques for perineal urethrostomy cannot be performed. CLINICAL RELEVANCE: PPU is a comparatively simple procedure that should be considered as a salvage technique for obstructive disease of the pelvic urethra.     

Subtotal penile amputation and preputial urethrostomy in a dog

CASE DESCRIPTION: A 6-year-old castrated male Shih Tzu was evaluated because of intermittent bleeding during urination. CLINICAL FINDINGS: Necrosis of the cranial portion of the penile shaft extended distally from the preputial fornix. Penile necrosis secondary to strangulation from paraphimosis was diagnosed. TREATMENT AND OUTCOME: A midline preputiotomy incision was used to expose the penile shaft; amputation was performed caudal to the preputial fornix. The terminal portion of the urethra was anastomosed to the preputial mucosa, which allowed the dog to urinate through the preputial orifice. CLINICAL RELEVANCE: Unlike the more conventional urethrostomy procedures performed in dogs, preputial urethrostomy eliminates the potential for local skin irritation during urination. Preputial urethrostomy is also easier to perform in those dogs in which penile amputation is required adjacent to the preputial fornix. A release incision cranial to the prepuce can be used to facilitate caudal displacement of the preputial mucosa, which facilitates urethral anastomosis to this structure. A midline preputiotomy incision provided excellent exposure of the penile shaft for this surgical procedure.     

Urolithiasis in small ruminants. II. Cysto-urethrography as a new aid in diagnosis

A technique for catheterizing male small ruminants is described. The barrier formed by the presence of the urethral diverticulum is avoided by the use of a pre-curved catheter. The technique enables application of contrast studies of bladder and urethra in animals suspected of urolithiasis. Differentiation between cystitis and obstructive urolithiasis is possible and the indications for urethrostomy can be reduced.     

Transpelvic urethrostomy in a Staffordshire bull terrier: a new technique in the dog

An eight-year-old male Staffordshire bull terrier was presented with a bleeding mass in the urethral mucosa 1.5 cm distal to the ischial arch. After cytological findings suggestive of a squamous cell carcinoma and confirmation of the mass with urethroscopy, total penile amputation followed by transpelvic urethrostomy using an ischial symphyseal ostectomy was performed. The procedure successfully produced a tension-free anastomosis of the urethra to the skin in the scrotal position and no major complications were observed in the postoperative period. Histologically, the lesion was reported as a ruptured vascular structure with thrombosis and repair tissue. Seven months after surgery the dog is free of clinical signs.     

Surgical procedure and postoperative management of a perineal urethrostomy in a chimpanzee (Pan troglodytes).

A chimpanzee (Pan troglodytes) with traumatic loss of the distal penis developed a gradually enlarging ventral urethral swelling and progressive dysuria. Endoscopy identified a urethral diverticulum, and endoscopic resection of the diverticulum wall was performed. Postoperative infection caused extensive necrosis of the penis, which necessitated a perineal urethrostomy. Complications of the urethrostomy included urethral obstruction from recurrent urethral stricture. The stricture was managed by regular dilatation using urethral bougies. Because of considerable postoperative swelling, catheterization was required to allow micturition following both the diverticular resection and polyp debulking. A shortened catheter sutured to the skin was tolerated for up to 10 days. Four yr after the urethrostomy, the animal is healthy and asymptomatic with endoscopic examinations performed at 12 mo intervals. This case demonstrates that with appropriate aftercare, perineal urethrostomy is an effective technique in the treatment of chronic distal urethral obstruction in the chimpanzee and probably other primate species.     

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.     

Simultaneous Bilateral Mastectomy in the Dog

Current reports advise against attempting simultaneous bilateral mastectomy in the dog. However, total mastectomy may be the most logical treatment for all dogs with mammary tumors in view of newer evidence suggesting a multicentric origin for this disease. A surgical technique for simultaneous bilateral mastectomy was evaluated in 22 dogs with mammary tumors. The procedure was successfully performed in selected patients and healing occurred without serious complications. The technique, rationale, and recommendations for use of this procedure are presented.