70 Feline Perineal Urethrostomy

Joshua Milgram
Veterinary Teaching Hospital, Koret School of Veterinary Medicine, Rehovot, Israel

Perineal urethrostomy (PU), a surgical procedure for the treatment Risk factors
of penile urethral obstruction and trauma in male cats, was first • Rupture of the postprostatic urethra may be caused by blunt or
reported in 1963 (Carbone 1963). The modifications of this tech- penetrating trauma, but iatrogenic trauma when attempting ret-
nique (Christensen 1964; Wilson and Harrison 1971; Yeh and Chin rograde urethral catheterization is more common (Ladlow 2014).
2000) are the commonly used surgical methods for the treatment of • Inadequate mucocutaneous apposition caused by:
urethral obstruction in male cats. ° Excessive tension on the suture line
The urethra of a male cat is divided into four anatomically discrete ° Technical error: misidentification of the urethral mucosa and
sections, preprostatic, prostatic, postprostatic, and penile urethra. failure to oppose the skin and mucosa
The order of the sections, based on increasing internal diameter is,
penile urethra (0.7 mm), postprostatic urethra at the level of the Diagnosis
bulbourethral glands (1.3 mm), and preprostatic urethra (2.0 mm) • Rupture of the postprostatic urethra may result in a fluctuant swelling
(Cullen et al. 1983). The diameter of the urethra at the level of the of the perineum and the dorsum around the tail base (Ladlow 2014).
bulbourethral glands is almost double the diameter of the penile • Marked hyperemia, pain, edema, and bruising of the perineal area
urethra and provides adequate luminal diameter (1.3 mm) for the and hindlegs immediately after performing a PU (Figure 70.1)
creation of a permanent stoma (Wilson and Harrison 1971; Phillips • Pain during and after urination (Ladlow 2014)
and Holt 2006). Failure to dissect cranially to this level results in • Dehiscence of stoma (Ladlow 2014)
the creation of stoma with a smaller diameter that is predisposed to • Necrosis and sloughing of the peristomal skin
stricture formation.
Treatment
Although perineal urethrostomy is usually a successful proce-
• Aspiration of the subcutaneous fluid (Holt 1989; Clarke and
dure when performed correctly, numerous serious complications
Findji 2011)
have been reported, including stricture formation and recurrent
• Placement of a small closed-suction drain (Holt 1989; Clarke and
obstruction, bacterial urinary tract infection (UTI), sterile cystitis,
Findji 2011)
subcutaneous urine leakage at the surgical site, urinary and fecal
incontinence, rectal prolapse, rectourethral fistula formation, and
perineal hernia (Smith and Schiller 1978; Gregory and Vasseur
1983; Gregory 1987; Scavelli 1989; Griffin and Gregory 1992; Hos-
good and Hedlund 1992).

Hemorrhage
See Chapter 12.

Wound dehiscence
See Chapter 9.

Subcutaneous urine leakage

Definition
• Leakage of urine into the subcutaneous tissues of the perineum Figure 70.1 A cat with subcutaneous leakage of urine after a transpelvic
and hindlimbs urethrostomy. Note the swelling and edema present in the perineal region
• Occurred in 25% of cats in one study (Bass et al. 2005) and thighs (Courtesy of Annick Hamaide).

Complications in Small Animal Surgery, First Edition. Edited by Dominique Griffon and Annick Hamaide.
© 2016 John Wiley & Sons, Inc. Published 2016 by John Wiley & Sons, Inc.
Companion website: www.wiley.com/go/griffon/complications

500
 Chapter 70 Feline Perineal Urethrostomy 501

• Urinary diversion with a cystostomy tube (Ladlow 2014) Urethral stricture

• Conservative management (Bass et al. 2005)
Definition
Outcome • Most commonly used to describe postoperative narrowing of the
• Necrosis of skin of the perineum or hindlimbs urethral stoma
• Considered to be a predisposing factor for stricture of the stoma
Risk factors
Prevention • Insufficient dissection of the urethra to the level of the bulboure-
• Atraumatic retrograde urethral catheterization thral glands
• Meticulous surgical technique • Excessive tension on sutures placed between the urethral mucosa
and the skin
• Subcutaneous urine leakage
Urinary incontinence • Suture pattern: No difference was found between the use of a
simple continuous pattern of absorbable material and a simple
Definition interrupted closure of nonabsorbable material to close a perineal
• Urinary incontinence is the loss of voluntary control of urina- urethrostomy (Agrodnia et al. 2004). However, a simple continu-
tion, resulting in leakage of urine from the urinary system to the ous pattern of absorbable material has been associated with a
exterior of the body. higher incidence of complications in cats referred for revision of
• Urinary incontinence is occasionally seen postoperatively after perineal urethrostomy (Bleedorn and Bjorling 2012).
perineal urethrostomy but is usually temporary (Smith and • Surgeon experience has been reported to be a contributing fac-
Schiller 1978; Gregory and Vasseur 1983; Scavelli 1989). tor to stricture formation (Smith and Schiller 1978). However, in
a later report, no difference was found between supervised resi-
Risk factors dents and senior staff surgeons (Bass et al. 2005).
• Excessive dorsal dissection with damage to the pelvic plexus • Postoperative use of urethral catheters (Smith and Schiller 1978)
• Excessive removal of the urethra with retention of inadequate • Self-induced trauma (Smith and Schiller 1978)
length of urethra (Ladlow 2014)
• Intraoperative damage to the pudendal nerve during the surgery Diagnosis
• Bladder damage during an obstructive episode • History of treatment, in the immediate postoperative period, for clini-
cal signs consistent with urine leakage (hyperemia of the surgical site,
Diagnosis edema and bruising of the perineal area and hindlegs).
• Diagnostic tests should be undertaken as needed to distinguish • Clinical signs include complaints of stranguria, urinary inconti-
between urinary incontinence and other causes of dysuria. nence, vocalization on urination, inappropriate urination, hema-
• These tests include urinalysis and culture, as well as ultrasonogra- turia, dyschezia, bruising of the perineum, licking at the urethral
phy and positive contrast studies of the lower urinary tract. stoma, vomiting, and weight loss (Phillips and Holt 2006).
• Urodynamic examination (urethral pressure profile and cystom- • A visible narrowed urethral stoma on physical examination
etry) may confirm the diagnosis if needed. (Figure 70.2).

Treatment
• Medical treatment is adapted depending on the etiology of the
urinary incontinence. In case of damage to the urethral sphincter,
the administration of α-adrenergic agents (e.g., phenylpropanola-
mine) may be attempted. If bladder dysfunction is suspected or
diagnosed, a urinary catheter should be left in place for at least
10 days, while parasympathicomimetic agents are administered.
• When the urinary incontinence is not responsive to medical
management, endoscopic injection of submucosal urethral bulk-
ing agents has been attempted to improve the continence with
limited success.

Outcome
• In most cases, spontaneous recovery may be expected.
• The prognosis for recovery is guarded in case of irreversible nerve
damage.

Prevention
• Avoid excessive dissection of the tissues dorsal to the penis.
• Avoid removal of excessive urethral length.

Urinary tract infection Figure 70.2 Stricture (pinpoint opening) after to a perineal urethrostomy
See Chapter 64. in a cat (Courtesy of Annick Hamaide).
502 Section 8 Surgery of the Urinary Tract

(A)

(C)

Figure 70.3 Surgical revision of a stricture consecutive to a perineal

urethrostomy (the same cat as in Figure 70.2). A, An elliptical incision is
made around the stenotic stoma and periurethral tissues are dissected.
B, The urethral remnant is dissected up to the bulbourethral glands. The
first suture is placed at the apex. C, The new urethral stoma is created
(B) (Courtesy of Annick Hamaide).
 Chapter 70 Feline Perineal Urethrostomy 503

• Ultrasonography and positive-contrast urethrocystogram might References

be necessary to exclude other causes of stranguria. Agrodnia, M.D., Hauptman, J.G., Stanley, B.J. (2004) A simple continuous pattern
using absorbable suture for perineal urethrostomy in the cat: 18 cases (2000-2002).
Journal of the American Animal Hospital Association 40, 479.
Treatment Baines, S.J., Rennie, S., White, R.A.S. (2001) Prepubic urethrostomy: a long-term study
• Revision of the stenotic stoma is generally possible because the in 16 cats. Veterinary Surgery 30, 107-113.
most common cause is incomplete dissection of the urethra. Bass, M., Howard, J., Gerber, B. (2005) Retrospective study of indications for and out-
• The surgical approach is similar to that for a standard perineal come of perineal urethrostomy in cats. Journal of Small Animal Practice 46, 227-231.
Bleedorn, J.A., Bjorling, D.E. (2012) Urethra. In Tobias, K.M. Johnston, S. (eds.) Veteri-
urethrostomy. An elliptical incision is made around the stenotic
nary Surgery Small Animal. WB Saunders, St. Louis.
stoma, and the urethra is undermined and mobilized as in the Carbone, M. (1963) Perineal urethrostomy to relieve urethral obstruction in the male
standard surgical approach. If a technical error is encountered cat. Journal of the American Veterinary Medical Association 143, 34-39.
(e.g., failure to cut the crura of the penis), it is corrected during Christensen, N.R. (1964) Preputial urethrostomy in the male cat. Journal of the Ameri-
the revision surgery. After the urethra has been adequately mobi- can Veterinary Medical Association 145, 903-8.
Clarke, B.S., Findji, L. (2011) Bilateral caudal superficial epigastric skin flap and per-
lized, the urethra is exposed and sutured depending on the tech- ineal urethrostomy for wound reconstruction secondary to traumatic urethral rup-
nique being used (Figure 70.3). ture in a cat. Veterinary Comparative Orthopedics and Traumatology 24, 142-145.
• Positioning in dorsal recumbency may be advantageous because Corgozinho, K.B., De Souza, H.J.M., Pereira, A.N., et al. (2007) Catheter-induced
it allows the surgeon to perform a cystotomy, if required, without urethral trauma in cats with urethral obstruction. Journal of Feline Medicine and
Surgery 9, 481-486.
the need to reposition the animal. In addition, dorsal recumbency
Cullen, W.C., Fletcher, T.F., Bradley, W.F. (1983) Morphometry of the male feline pelvic
simplifies the conversion to a prepubic or subpubic urethrostomy urethra. Journal of Urology 129, 186-189.
if the revision of the PU fails. Eggertdottir, A.V., Lund, H.S., Krontveit, R., et al. (2007) Bacteria in cats with feline
lower urinary tract disease: a clinical study of 134 cases in Norway. Journal of Feline
Outcome Medicine and Surgery 9, 458-465.
Forrester, S.D., Roudebush, P. (2007) Evidence-based management of feline lower urinary
Revision of the structure has a good prognosis, particularly if the tract disease. Veterinary Clinics of North America Small Animal Practice 37, 533-538.
cause of the stricture was inadequate dissection of the urethra. Gerber, B., Boretti, F.S., Kley, S., et al. (2005) Evaluation of clinical signs and causes of lower
urinary tract disease in European cats. Journal of Small Animal Practice 46, 571-577.
Prevention Gerber, B., Eichenberger, S., Reusch, C.E. (2008) Guarded long-term prognosis in male
cats with urethral obstruction. Journal of Feline Medicine and Surgery 10, 16-23.
• It is important to cut the pelvic attachments of the urethra to
Gregory, C.R. (1987) The effects of perineal urethrostomy on urethral function in male
allow adequate mobilization of the urethra. cats. Compendium on Continuing Education for the Practicing Veterinarian 9, 895-899.
• Mobilize the urethra until the bulbourethral glands are at the Gregory, C.R., Vasseur, P.B. (1983) Long-term examination of cats with perineal ure-
level of the skin incision. throstomy. Veterinary Surgery 12, 210-212.
• Precise apposition of urethral mucosa to the skin Griffin, D.W., Gregory, C.R. (1992) Prevalence of bacterial urinary tract infection after
perineal urethrostomy in cats. Journal of the American Veterinary Medical Associa-
• Tension-free apposition of urethral mucosa to the skin tion 200, 681-684.
• Self-induced trauma should be prevented. Holt, P.E. (1989) Hindlimb skin loss associated with urethral rupture in two cats. Jour-
nal of Small Animal Practice 30, 406-409.
Hosgood, G., Hedlund, C.S. (1992) Perineal urethrostomy in cats. Compendium on
Continuing Education for the Practicing Veterinarian 14, 1195-1205.
Relevant literature Hostutler, R.A., Chew, D.J., Dibartola, S.P. (2005) Recent concepts in feline lower urinary
Perineal urethrostomy has been reported to result in a long-term tract disease. Veterinary Clinics of North America Small Animal Practice 35, 147-170.
disease-free outcome for the majority of cats. The procedure is Kruger, J.M., Osborne, C.A., Lulich, J.P. (2009) Changing paradigms of feline idio-
well accepted by clients, and the majority of clients consider their pathic cystitis. Veterinary Clinics of North America Small Animal Practice 39, 15-40.
cats to have a good quality of life (Bass et al. 2005; Corgozinho Ladlow, J.F. (2014) Urethra. In Langley-Hobbs, S.J., Demetriou, J.L., Ladlow, J.F. (eds.)
Feline Soft Tissue and General Surgery. Elsevier, Philadelphia.
et al. 2007; Ruda and Heiene 2012). In one study, however, the Phillips, H., Holt, D.E. (2006) Surgical revision of the urethral stoma following perineal
authors concluded that although the rate of reobstruction was urethrostomy in 11 cats: (1998-2004). Journal of the American Animal Hospital
low in the operated group (20%) compared with the nonoperated Association 42, 218-222.
group (36%) of cats, there was no reduction in the recurrence Ruda, L., Heiene, R. (2012) Short- and long-term outcome after perineal urethrostomy
in 86 cats with feline lower urinary tract disease. Journal of Small Animal Practice
of clinical signs of feline lower urinary tract disease between
53, 693-698.
the operated (50%) and the nonoperated (51%) groups of cats Sævik, B., Trangerud, C., Ottesen, N., et al. (2011) Causes of lower urinary tract disease
(Gerber et al. 2008). In Norwegian cats. Journal of Feline Medicine and Surgery 12, 410-417.
The most frequently reported complication of PU is recurrent Scavelli, T. (1989) Complications associated with perineal urethrostomy in the cat.
UTI. There is a wide reported incidence of UTI associated with PU, Problems in Veterinary Medicine 1, 111-119.
Segev, G., Livne, H., Ranen, E., et al. (2011) Urethral obstruction in cats: predisposing
which may vary from symptomatic to asymptomatic or self-limit- factors, clinical, clinicopathological characteristics and prognosis. Journal of Feline
ing (Smith and Schiller 1978; Gregory and Vasseur 1983; Griffin Medicine and Surgery 13, 101-108.
and Gregory 1992; Baines et al. 2001; Bass et al. 2005; Corgozinho Smith, C.W., Schiller, A.G. (1978) Perineal urethrostomy in cat—retrospective study of
et al. 2007; Gerber et al. 2008). A wide reported incidence of UTI complications. Journal of the American Animal Hospital Association 14, 225-228.
Westropp, J. L., Buffington, T.C.A. (2010) Lower urinary tract disorders in cats. In Ettinger,
has also been reported in cats with feline lower urinary tract dis-
S.J. (ed.) Textbook of Veterinary Internal Medicine, 7th edn. WB Saunders, St Louis.
ease that were not treated surgically (Gerber et al. 2005; Hostutler Wilson, G.P., Harrison, J.W. (1971) Perineal urethrostomy in cats. Journal of the Ameri-
et al. 2005; Eggertdottir et al. 2007; Forrester and Roudebush 2007; can Veterinary Medical Association 159, 1789-1793.
Kruger et al. 2009; Sævik et al. 2011; Segev et al. 2011; Westropp Yeh, L.H., Chin, S.C. (2000) Modified perineal urethrostomy using preputial mucosa
and Buffington 2010). in cats. Journal of the American Veterinary Medical Association 216, 1092-1095.