Topics in Compan An Med 32 (2017) 55–57

Submucosal Collagen Injection for Management of Urinary Incontinence Following Urethral Stent Placement Scott Kilpatrick, BSc (Hons), BVMS, MRCVS, DipECVIM-CAa,1, Tracy Hill, DVM, DACVIM, PhD, DipECVIM-CAb,⁎ Keywords: submucosal collagen bulking incontinence cystoscopy urethral stent a

The Hospital for Small Animals, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Roslin, Midlothian, UK

An 8-year-old, entire, male British Bulldog was referred for a week-long history of severe stranguria and dysuria. A prostatic wash was diagnostic of prostatic carcinoma. A transluminal urethral stent was placed in the proximal urethra, which resulted in resolution of the urinary obstruction, however, the dog developed severe urinary incontinence after the procedure. Cystoscopically-guided submucosal collagen injections were performed immediately proximal to the os penis. The dog's incontinence resolved with a single collagen injection for the 10-month follow-up period. & 2017 Elsevier Inc. All rights reserved.

b

Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA

⁎ Address reprint requests to: Tracy Hill, University of Georgia College of Veterinary Medicine, 2200 College Station Rd, Athens, GA 30601, USA.

E-mail: [email protected] (T. Hill)

Introduction Prostatic carcinoma is the most common neoplasia of the prostate in dogs. Common clinical signs include dysuria and urinary obstruction, dyschezia, hind limb pain, and ataxia.1 Because of the aggressive nature of canine prostate cancer, up to 80% exhibit significant local invasion and widespread visceral metastases at the time of diagnosis.2 Urethral self-expanding metallic stent placement has been demonstrated to be a rapid, safe, effective, and minimally invasive palliative treatment option for alleviation of urethral obstruction and stranguria in dogs with obstructive carcinoma in the urethra.3-6 The main complication of stent placement is urinary incontinence, which was detected in 47.4% of female dogs and 78.2% of male dogs after self-expanding metallic stent placement.3 There are no reports of successful treatment of incontinence that develops secondary to stent placement. This case report describes the use of submucosal urethral collagen injection for treatment of incontinence following stent placement. Submucosal collagen has been used for the management of urethral sphincter mechanism incontinence in female dogs, particularly after failure of pharmacologic management.7

Case Description An 8-year-old male entire British Bulldog was presented for investigation of a 7-day history of stanguria and dysuria. The dog had a history of urate urolithiasis 1 year prior that had been successfully managed surgically. An appropriate stone prevention 1

Present address: Vets Now, Glasgow, UK.

http://dx.doi.org/10.1053/j.tcam.2017.07.005 1527-3369 & 2017 Topics in Companion Animal Medicine. Published by Elsevier Inc.

diet was prescribed and the dog had not shown clinical signs related to urolithiasis for the previous 12 months. On clinical examination, the dog demonstrated marked dysuria with several unsuccessful attempts to micturate during the initial consultation. Routine hematology and biochemistry revealed no significant abnormalities. Urinalysis by cystocentesis revealed urine specific gravity of 1.030, bloodþþþ, proteinþþ with unremarkable sediment examination. Urine culture was negative. Abdominal ultrasonography revealed nonobstructive right renal calculi and mild-chronic cortical changes bilaterally. A nodule was detected on the left testicle. The prostate was large and contained numerous hypoechoic cystic lesions (Fig 1). Sediment was detected in the urinary bladder. FNA samples were taken from the left testicle confirmed the presence of seminoma. Cytology of a prostatic wash was consistent with well-differentiated carcinoma (Fig 2). Multiple treatment options were discussed, including chemotherapy, nonsteroidal anti-inflammatory drugs, palliative radiation therapy, urethral stent placement, and cystostomy tube placement. Because of the dog's apparent urinary obstruction, a urethral stent was placed in the proximal urethra, bridging the obstructive prostatic neoplasia, under fluoroscopic guidance as previously described (Fig 3).4 Castration was also performed at this time. The dog recovered uneventfully and was able to micturate without stranguria immediately following recovery from anesthesia. Severe incontinence was noted, exhibited by constantly dribbling urine; grade 2-3 of 10 on a previously published continence scoring system.8 Medical management was unsuccessfully attempted with phenylpropanolamine (0.8 mg/kg p.o. q8 h) and oestriol (1 mg/dog p.o. q24 h). Three weeks following stent placement, endoscopic submucosal urethral injection of collagen was performed similarly to previous reports.9 While under general anesthesia, the dog was

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S. Kilpatrick, T. Hill / Topics in Companion An Med 32 (2017) 55–57

Fig. 1. Ultrasonographic image demonstrating prostatic mass.

positioned in dorsal recumbency. A 2.7 Fr rigid cystoscope was passed into the penile urethra. Three circumferential submucosal injections of collagen2 were injected immediately proximal to the os penis; a second set of circumferential injections was given 1 cm proximal to the first. Bulging of mucosa was observed at the outset during each injection, suggesting correct submucosal location, however, each injection site rapidly spread to become more diffuse and less clearly defined. Mild-to-moderate hemorrhage occurred with each collagen injections. The urethral lumen was mildly narrowed at the completion of the procedure. In the 48 hours following the procedure the dog was attributed a continence score of 4. After the dog's discharge from the hospital, the dog remained fully continent at home (continence score 10/10). The dog remained fully continent at the time of writing (10 months). The dog was managed with chronic meloxicam therapy for the prostatic carcinoma.

Discussion Transluminal urethral stents are an effective, safe option in the palliative treatment of malignant obstructive urethral disease.3-6 Moderate-to-severe incontinence is a relatively frequent reported complication, affecting approximately 50% of male dogs receiving urethral stents.3 Transurethral submucosal collagen has been used for the management of urethral sphincter mechanism incontinence in female dogs, particularly after failure of pharmacologic management.7

Fig. 3. Survey radiograph demonstrating stent bridging prostate.

This treatment modality produces a significant improvement in continence scores for a mean of 16.4 months. Client satisfaction was excellent despite lack of complete continence in some dogs.7,10 Transurethral collagen injections are used in the management of male human patients with postprostatectomy incontinence, producing a 50% improvement in continence scores for a mean duration of 6 months.11 There are no published reports of the use of transurethral submucosal collagen in the management of male dog incontinence, especially related to the placement of a urethral stent. Normally, coaptation of the urethral mucosa is described and is thought to contribute to the effectiveness of the procedure in female dogs.7 Bulging of the urethral mucosa was observed in this case, but was seen to dissipate quickly, with no real narrowing of the urethra observed. Despite this, the procedure was still successful. The authors had counseled the client that the submucosal injections at the penile urethra were unlikely to significantly improve the dog's urinary incontinence; a complete resolution of incontinence so close to the procedure was unexpected. It is possible that the improvement of incontinence was unrelated to the treatment or specifically to the collagen injection though the close temporal association to collagen injections suggests some causality. This case demonstrates the potential use of transurethral submucosal collagen for management of incontinence in male dogs subsequent to urethral stent placement. Further investigation would be needed to determine if submucosal collagen in the penile urethra could repeatedly show efficacy in the treatment of post stent incontinence. Additionally, the duration of action in male dogs would need to be determined; given the length of survival of dogs with prostatic carcinoma it is likely the dog in this case will not outlive the effects of the collagen. Penile transurethral submucosal collagen may be a reasonable option in dogs with severe incontinence post stent placement.

References

Fig. 2. Prostatic wash cytology showing dysplasia, multiple nucleoli, pleocytosis consistent with prostatic carcinoma. (Color version of figure is available online.)

2

Avalon Medical, Stillwater, MN.

1. Leroy BE, Northrup N. Prostate cancer in dogs: comparative and clinical aspects. Vet J 180:149–162, 2009 2. Cornell KK, Bostwick DG, Cooley DM, et al. Clinical and pathologic aspects of spontaneous canine prostate carcinoma: a retrospective analysis of 76 cases. Prostate 45:173–183, 2000 3. Blackburn AL, Berent AC, Weisse CW, et al. Evaluation of outcome following urethral stent placement for the treatment of obstructive carcinoma of the urethra in dogs: 42 cases (2004-2008). J Am Vet Med Assoc 242:59–68, 2013 4. Weisse C, Berent A, Todd K, et al. Evaluation of palliative stenting for management of malignant urethral obstructions in dogs. J Am Vet Med Assoc 229:226–234, 2006 5. Berent AC, Weisse C, Beal MW, et al. Use of indwelling, double-pigtail stents for treatment of malignant ureteral obstruction in dogs: 12 cases (2006-2009). J Am Vet Med Assoc 238:1017–1025, 2011

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6. McMillan SK, Knapp DW, Ramos-Vara JA, et al. Outcome of urethral stent placement for management of urethral obstruction secondary to transitional cell carcinoma in dogs: 19 cases (2007-2010). J Am Vet Med Assoc 241: 1627–1632, 2012 7. Byron JK, Chew DJ, McLoughlin ML. Retrospective evaluation of urethral bovine cross-linked collagen implantation for treatment of urinary incontinence in female dogs. J Vet Intern Med 25:980–984, 2011 8. Byron JK, March PA, Chew DJ, et al. Effect of phenylpropanolamine and pseudoephedrine on the urethral pressure profile and continence scores of incontinent female dogs. J Vet Intern Med 21:47–53, 2007

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9. Arnold S, Hubler M, Lott-Stolz G, et al. Treatment of urinary incontinence in bitches by endoscopic injection of glutaraldehyde cross-linked collagen. J Small Anim Pract 37:163–168, 1996 10. Barth A, Reichler IM, Hubler M, et al. 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). J Am Vet Med Assoc 226:73–76, 2005 11. Westney OL, Bevan-Thomas R, Palmer JL, et al. Transurethral collagen injections for male intrinsic sphincter deficiency: the University of Texas-Houston experience. J Urol 174:994–997, 2005

Submucosal Collagen Injection for Management of Urinary Incontinence Following Urethral Stent Placement.

An 8-year-old, entire, male British Bulldog was referred for a week-long history of severe stranguria and dysuria. A prostatic wash was diagnostic of ...
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