Prepubic Urethrostomy for Surgical Correction of the Urethral Stricture and Rectourethral Fistula after Perineal Urethrostomy in a Cat

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J Vet Clin 29(4) : 331-333 (2012)

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Prepubic Urethrostomy for Surgical Correction of the Urethral Stricture and Rectourethral Fistula after Perineal Urethrostomy in a Cat

Su-Young Heo, Hae-Beom Lee and Nam-Soo Kim¹

College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Jeonju 561-756, Korea (Accepted: July 04, 2012)

Abstract : A 2-year-old, castrated male domestic short-haired cat was presented with dysuria. The physical and radiographic examinations were revealed the urethral stricture and rectourethral fistula after perineal urethrostomy (PU).

A prepubic urethrostomy was performed to resolve these problems. After the treatment, the cat had normal urination and complete wound healing without any complications. This is the first case report on co-occurrence of the urethral stricture and rectourethral fistula after PU in the cat.

Key words : urethral stricture, rectourethral fistula, prepubic urethrostomy, perineal urethrostomy, cat.

Introduction

Feline lower urinary tract diseases (FLUTD) are frequently encountered in clinical medicine (7,9). Urethral obstruction is a common problem in male cats. Of cats with FLUTD, ap- proximately 7.4% and 18% have been reported to be ob- structed (5,7). The major causes of urethral obstruction are urethral plugs, uroliths, idiopathic, and granulomatous masses (7,9). In addition, the male cats are more prone to obstruction because of narrowing of penile urethra (10). Most of these cases have been successfully treated by non-surgical techniques, including penile massage and retrograde urethral flushing (9). However, if the problems are not resolved by the aforementioned techniques, surgical techniques are demanded to solve the problem.

In the management of FLUTD, the most commonly performed surgical procedure is perineal urethrostomy (PU) (2,4). This technique creates a permanent opening between the pelvic urethra and the skin in the perineal site (4). Previ- ously, the PU has been reported to be associated with severe complications like hemorrhage from erectile tissue, wound dehiscence, cystitis or ascending urinary tract infection, urethral stricture, urinary and fecal incontinence, perineal hernia, and rectourethral fistula (2,4,6). The occurrence of rectourethral fistula with urethral stricture is a very rare complication (2,4,6). Such complications need to be corrected by surgical procedure. Although, the presence of such complications after PU has been reported in previous studies, until date no case study has reported co-occurrence of urethral stricture and rectourethral fistula after PU.

The purpose of this case study was to discuss the occur-

rence of the urethral stricture and rectourethral fistula after PU in male cat and outcomes of surgical correction of the complications after PU.

Case

A 2-year-old, castrated male domestic short-haired cat weighing 3.8 kg was presented to the Chonbuk Animal Med- ical Center of Chonbuk National University for dysuria. The owner noted that the cat has received animal shelter about 2 months back. The previous history and medical treatment were unknown. Before 2 weeks, the cat had to make increased attempts to urinate. The physical examination revealed dilation of urinary bladder to abdomen palpation, inflammation of anus, and pinpoint urethral opening (Fig 1). A complete blood count and the serum biochemistry analysis were evalu- ated. The complete blood count results were all within the

1Corresponding author.Nam-Soo Kim E-mail: namsoo@chonbuk.ac.kr

Fig 1. The appearance of pinpoint urethral opening after perineal urethrostomy (arrow).

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332 Su-Young Heo, Hae-Beom Lee and Nam-Soo Kim

normal limits. The serum biochemistry analysis demonstrated a mild increase in the levels of blood urea nitrogen (48 mg/dl;

reference range, 10 to 30 mg/dl), and creatinine (2.1 mg/dl;

reference range, < 1.7 mg/dl). The radiology and ultrasonography after intramuscular sedation with 50µg/kg medetomi- dine (Domitor^®, Pfizer Animal Health, USA) were performed.

The ultrasonography showed the presence of uroliths within the urinary bladder and thickening of the urinary bladder wall (Fig 2a). The positive contrast radiography confirmed the presence of fistula between pelvic urethra and rectum and dilation of pelvic urethra (Fig 2b). Based on these results, the cat was diagnosed to be suffering from the urethral stricture and rectourethral fistula due to complications after PU. After discussing about the surgical options with the owner, the decision was made to perform a prepubic urethrostomy to resolve these problems.

Prior to surgery, the cat was administered preoperative cephalexin (20 mg/kg IM, Methilexin Inj^®, Union Korea Pharm) for prophylaxis. The cat was premedicated with propofol (5 mg/kg IV, Anepol IN^®; Ha Na Pharm, Seoul, Korea) administered intravenously and general anesthesia was maintained with isoflurane in oxygen.

The cat was positioned in a dorsal recumbency position, and prepared for aseptic perineal and ventral abdominal surgery. A prepubic urethrostomy, as described by Baines et al (1), was performed. A ventral median celiotomy was used to expose the urinary bladder. After ventral cystotomy, the uroliths were removed from the bladder and irrigated with sterile saline. The urethral was elevated using a penrose drain, and ligated around the distal of urethra. An open- ended tomcat catheter was inserted into preprostatic urethra and the cystotomy was closed (Fig 3a). Simple interrupted 4- 0 polyglycolic acid sutures were used to suture the urethral mucosa without imparting any tension to the abdomen skin (Fig 3b). The subcutaneous tissues and skin were closed rou- tinely. An 8 Fr foley catheter was inserted into newly cre- ated urethral stoma. Postoperatively, an Elizabethan collar was placed immediately to protect the surgical site. The catheter of urethra was removed after 2 days. The cat was administered cephalexin (15 mg/kg IV Methilexin Inj^®, Union Korea Pharm, every 12 hours for 5 days), and the sutures were

removed at 14 days.

During the postoperative follow-up, at 3 months, no stric- tures of urethral opening were noted. After the hair growth around the urethral stoma, the occurrence of urine-scald dermatitis was seen around the urethral opening. We advised to cut the hair around the urethral stoma to protect urine-scald dermatitis, although the cat had mild urine-scald dermatitis around urethral opening at 6 months follow-up, and urine passed freely through the urethral opening (Fig 4). No other complications were noted.

Discussion

Complications of PU have been reported in previous studies (2,4,5,6). Stricture of the urethral opening mostly occurs due to performance of inappropriate surgical technique. A previous study has demonstrated the presence of urethral stricture in 37 out of 204 cats after PU. All the cases of PU resulted from incomplete mobilization and dissection of the penis and its pelvic attachments with failure to correctly extend the urethral incision to the level of the pelvic urethra (5). In another study, early complications after PU were noted in 15 out of 59 cats. The most common of these was urethral stricture formation at the mucocutaneous junction of the stoma (2). In our case, although the initial surgical techniques were unknown, urethral stricture was associated with Fig 2. Ultrasonography and positive contrast radiography show-

ing the presence of uroliths within the urinary bladder and thickening of the urinary bladder wall (a) and the presence of fistula between pelvic urethra and rectum and dilation of pelvic urethra (arrow) (b).

Fig 3. Photograph of intraoperative view. Note the closed cystotomy and insertion of an open-ended tomcat catheter in preprostatic urethra (a), and creating the prepubic urethral stoma (b).

Fig 4. Photograph of clinical outcome. The urethral opening in abdomen on sixth month after prepubic urethrostomy.

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Prepubic urethrostomy for surgical correction in a cat ₃₃₃

improper techniques, postoperative use of urethral catheters and grooming of the surgical site. Surgical revision of urethral stricture has previously been described after PU. The authors reported that in 8 out of 11 cats, the dissection did not involve the urethra to the level of the bulbourethral glands.

Suturing of the narrow penile urethra to the skin presumably resulted in an inadequate stoma that had subsequently stric- tured (8). The use and misuse of urethral catheters have been shown to increase the risk of stricture formation and the risk of urinary tract infection (4,5).

The occurrence of rectourethral fistula after PU is a very rare occurrence. In one case, rectourethral fistula and perineal hernia have been reported after PU (6). In another case, this complication was present along with laceration of the rectum due to dissection of the retractor penis muscle from its attachment to the anal sphincter and rectum and further pen- etration to the rectum (10). However, to the best of the authors' knowledge, this is the first case report on co-occurrence of the urethral stricture and rectourethral fistula after PU in the cats.

Urethral plugs and urethroliths have been reported as the most common causes of obstruction in male cats (2). Other potential causes include urethrospasm, trauma, congenital defects, stricture and neoplasia (7,9). Urethral obstructions are most commonly seen in male cats due to the small diameter of the male urethra (10). The diameter of the penile urethra begins to constrict like a cone. Therefore, inadequate dissection of the penile urethra creates an opening from a portion of the urethra with a small diameter. Excessive wound tension may result in wound contraction and stricture formation at the site of an initially small opening (8).

The aim of urethrostomy is to remove the common site of urethral obstructions and to create new urethral opening. The PU is most commonly used in the management of FLUTD (2,4). The prepubic and transpelvic are known as other surgical procedures in FLUTD. Such procedures are most commonly used for the primary treatment of urethral obstruction or a salvage procedure after PU failure (2,3). A pervious study on prepubic urethrostomy reported high level of com-

plications by following the technique (1). Other surgical options such as transpelvic urethrostomy could have resulted in good outcome (3). However, in our case, it was impossible to perform transpelvic urethrostomy because of the presence of fistula between pelvic urethra and rectum and inflammation of the pelvic urethra.

To the best of authors' knowledge, this is the first case report on co-occurrence of the urethral stricture and rectourethral fistula after PU in a cat. PU should be carefully decided in male cats with FLUTD. Correctable surgical technique is the best way to minimize the complications after urethrostomy.

REFERENCE

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3. Bernarde A, Viguier E. Transpelvic Urethrostomy in 11 Cats Using an Ischial Ostectomy. Vet Surg 2004; 33: 246-252.

4. Charles WS. Perineal urethrostomy. Vet Clin North Am Small Anim Pract 2002; 32: 917-925.

5. Gregory CR, Vasseur PB. Long-term Examination of Cats with Perineal Urethrostomy. Vet Surg 1983; 12: 210-212.

6. Johnson MS, Gourley IM. Perineal hernia in a cat: a possible complication of perineal urethrostomy. Vet Med Small Anim Clin 1980; 75: 241-243.

7. Lekcharoensuk C, Osborne CA, Lulich JP. Evaluation of trends in frequency of urethrostomy for treatment of urethral obstruction in cats. J Am Vet Med Assoc 2002; 221: 502-505.

8. Phillips H, Holt DE. Surgical revision of the urethral stoma following perineal urethrostomy in 11 cats:(1998-2004). J Am Anim Hosp Assoc 2006; 42: 218-222.

9. Saevik BK, Trangerud C, Ottesen N, Sorum H, Eggertsdottir AV. Causes of lower urinary tract disease in Norwegian cats.

J Feline Med Surg 2011; 13: 410-417.

10. Wang B, Bhadra N, Grill WM. Functional anatomy of the male feline urethra: morphological and physiological correl- ations. J Urol 1999; 161: 654-659.

고양이에서 회음부 요도개구술 후 발생한 직장요도 루 및 요도 협착의 외과교정을 위한 치골 요도개구술 증례

허수영·이해범·김남수¹

전북대학교 수의과대학, 생체안전성연구소

요 약 : 두 살 된, 거세된 수컷, 단모종 고양이가 배뇨곤란을 주 증으로 내원하였다. 신체검사 및 방사선 검사에서 회 음부 요도개구술 후 직장요도루 및 요도 협착이 발생한 것으로 진단되었다. 이 문제를 해결하기 위하여 치골 요도개 구술을 실시하였다. 이후 합병증 없이 창상 치유가 잘 이루어져 정상적인 배뇨가 이루어지고 있다. 고양이에서 회음부 요도개구술 후 요도 협착과 직장요도 루가 동시에 발생한 첫 번째 증례이다.

주요어 : 요도 협착, 직장요도 , 치골 요도개구술, 회음부 요도개구술, 고양이