My Dog Continues to Lick Her Uretha After Surgery for Bladder Stones W
Can Vet J. 2012 Jul; 53(7): 787–790.
Language: English | French
Suture-related urolithiasis following repair of inadvertent prostatectomy in a dog
Abstract
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.
Résumé
Urolithiase causée par des sutures après la réparation d'une prostatectomie par inadvertance chez un chien. Un chien Chow-Chow mâle de race croisée âgé de 10 mois a été présenté pour de l'anurie causée par une prostatectomie par inadvertance réalisée durant la cryptorchidectomie unilatérale. Une réparation chirurgicale a été réalisée avec succès. Cependant, cela a causé la formation d'urolithes associés aux sutures 3 mois plus tard, ce qui a exigé une deuxième intervention chirurgicale et l'urétrotomie.
(Traduit par Isabelle Vallières)
Inadvertent prostatectomy is a known complication associated with canine cryptorchidectomy but urethral stricture formation and urinary incontinence are the most common sequelae following repair (1,2). Here we report the formation of suture-related struvite urolithiasis resulting in stranguria as a complication of the original surgical procedure.
Case description
A 10-month-old, 27.9 kg male chow chow mixed breed dog was presented to the Western Veterinary Specialist Center of Edmonton for evaluation of anuria and lethargy 72 h after a right cryptorchidectomy had been performed elsewhere. On presentation, the dog's vital parameters were within normal limits; however, he was straining to urinate and a moderate amount of sero-sanguinous fluid was leaking from a right peripreputial incision. Abdominal palpation was difficult given the dog's discomfort; however, a severely enlarged bladder was detected.
Bloodwork revealed a mild leukocytosis of 18.2 × 109/L [reference interval (RI): 6 to 17 × 109/L] characterized by a mild mature neutrophilia of 15.6 × 109/L (RI: 3.5 to 12 × 109/L). Abnormalities on the serum biochemistry panel included severe azotemia (blood urea nitrogen of 48.50 mmol/L; RI: 3.21 to 10.35 mmol/L), elevated creatinine (916 mmol/L; RI: 35 to 124 μmol/L), severe hyperphosphatemia (3.81 mmol/L; RI: 0.61 to 1.61 mmol/L), mild hypercalcemia (3.38 mmol/L; RI: 2.25 to 3.00 mmol/L), mild hypermagnesemia (1.22 mmol/L; RI: 0.62 to 0.99 mmol/L), and mild hyponatremia (138 mmol/L; RI: 141 to 152 mmol/L). Following sedation, urethral catheterization was performed. No urine could be retrieved through the catheter. A contrast cystourethrogram with dilute iohexol (Omnipaque, Iohexol Injection 240 mg I/mL diluted 3:1 with sterile saline; GE Healthcare Canada, Mississauga, Ontario) was performed, revealing leakage of the contrast material directly into the abdomen from the proximal urethra. Suspecting a severely devitalized bladder based on the leakage of contrast material, cystocentesis for the purpose of a urinalysis was not performed prior to surgery.
The patient was taken to surgery on an emergency basis. A caudal ventral midline approach into the abdominal cavity was performed, incorporating the previous right peripreputial incision. There was a small amount of purulent fluid within the subcutaneous tissues and this was cultured, resulting in a 1+ growth of Mycoplasma spp. Upon entering the abdomen a dramatically enlarged bladder was immediately apparent. The bladder wall was very thin, and had numerous areas which were hemorrhagic to black, consistent with necrosis. A ligature was present around the neck of the bladder, approximately 2 cm caudal to the ureteral openings, preventing drainage of urine. The ligature was removed and a large volume of dark, foul smelling urine was evacuated. Both ureters were traced cranially from the bladder and were found to be markedly enlarged along their entire length. Measurements of the ureters were not obtained, but they were estimated to be 6 to 7 mm in diameter.
A urinary catheter was introduced through the penile urethra and was found to enter the abdomen through a transected proximal urethra at the level of the pubis. The prostate was absent. The free edges of the bladder neck and proximal urethra were debrided until bleeding tissue was apparent. A 10 French Foley catheter (Smiths Medical PM, Waukesha, Wisconsin, USA) was placed through the penile urethra and guided into the bladder before the bladder and urethra were anastomosed using 3-0 PDS (Ethicon, San Antonio, Texas, USA) in an interrupted pattern. Sutures were placed to achieve an appositional closure, and suture spacing was adjusted to accommodate the mild to moderate disparity in lumen diameters. Efforts were made to avoid penetrating the mucosal surface with the suture material. A large necrotic section of the dorsal cranial bladder wall (estimated to include approximately 1/3 of the bladder) was also resected until bleeding edges were apparent and the defect was closed with 3-0 PDS in an appositional and then an inverting pattern.
Mucosal penetration with the suture material occurred during repair of the bladder, given its thin appearance and our concerns regarding the integrity of the bladder wall. Omentum was then wrapped around the bladder and anastomosis site prior to abdominal lavage and closure. Finally, the cryptorchid right testicle was identified within the inguinal ring, ligated and removed. During recovery from anesthesis an indwelling urinary catheter was left in place so that urine production could be monitored. Within 72 h of surgery, the urine was grossly normal in appearance and the dog's serum biochemistry results had normalized. Four days after surgery, dehiscence of the peripreputial component of the incision was apparent, including body wall, subcutaneous tissues, and a portion of the skin incision. There was no herniation of any abdominal contents. Revision surgery was performed to debride the inflamed and necrotic tissue and to allow for repeat closure of the linea alba using interrupted sutures. A wet-to-dry "tie over" bandage was used to treat the soft tissue component of the wound. Eight days following the urethral repair, the dog was anesthetized so that the soft tissue component of the wound could be closed and so that a contrast cystourethrogram could be performed. No further evidence of leakage of contrast material was apparent and the urinary catheter was removed. Despite mild intermittent urine dribbling, the dog was discharged the following day, having demonstrated the ability to voluntarily void his bladder.
One month after surgery the dog was seen again for persistent urinary incontinence. Although he would consciously urinate in an apparently normal manner, he would not completely void his bladder and he dribbled urine constantly. A urine culture performed at that time was negative. Treatment with phenylpropanolamine (Vétoquinol, Lavaltrie, Quebec) was initiated [1 mg/kg body weight (BW), PO, q8h]. Within 2 wk of starting treatment, no dribbling was noted, and the dog was consistently urinating consciously according to the owner.
The dog was returned to the Western Veterinary Specialist Center of Edmonton 2 mo later with an acute 1-day history of constant straining to urinate and a diffusely painful abdomen. Palpation along the length of the distal urethra revealed a firm elongated structure approximately 4 to 6 cm in length immediately proximal to the os penis. Palpation in the region resulted in a prominent pain response. Radiographs of the caudal abdomen showed a severely enlarged bladder with no visible stones throughout the length of the urethra. An attempt to pass a urinary catheter was unsuccessful due to a presumed obstruction 10 to 12 cm from the urethral opening. Abnormalities in a sample of urine collected by cystocentesis included the presence of 1 to 2 white blood cells and 2 to 5 red blood cells per high power field in the sediment, as well as occasional amorphous crystals. Urine for culture was also obtained at that time via cystocentesis, and had no bacterial growth. A complete blood (cell) count and serum biochemistry had been performed elsewhere prior to presentation and were within normal limits.
The dog was taken to surgery so that a scrotal urethrotomy could be performed, directly over the firm palpable mass. This revealed a 6-cm urethral plug, grossly consisting of what appeared to be suture fragments, crystals, and blood clots. This mass was removed from the urethra in its entirety (Figure 1). Proximal to the urethrotomy there were several similar 4- to 5-mm plugs, which were removed with thumb forceps. A left peripreputial incision was made and carried through the linea to gain access to the caudal abdomen. The bladder was exposed and a ventral cystotomy was performed, where several small suture remnants were present in the mucosa. Small aggregations of crystals were associated with, and adherent to the sutures. The suture aggregates were removed, the bladder was flushed with saline, and patency into the urethra was confirmed. The bladder and urethral anastomosis site from the previous surgery could be palpated and appeared to have healed appropriately with no obvious strictures. The bladder was closed with 3-0 Monocryl (Ethicon) in a continuous appositional pattern without entering the bladder lumen. The bladder was tested for leaks and the abdominal incision was closed. The urethrotomy was then converted to an urethrostomy.
Urethral plug consisting of suture fragments, crystals, and blood clots. The plug was removed from the urethra immediately proximal to the os penis and measured approximately 6.5 cm.
The dog remained in hospital overnight for post-operative monitoring and was discharged the following day. The urethral plug was submitted to the Minnesota Urolith Center (University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota, USA) and was found to consist of multiple intact uroliths containing magnesium ammonium phosphate. At his last recheck 1 wk later, the dog appeared to be urinating normally and the surgical site was healing appropriately.
Follow-up through a telephone call was obtained 3 mo following the second surgery. The patient was doing well, urinating normally, and had no further episodes of stranguria. No tests were done to document further urolith or urethral plug formation.
Discussion
This case report describes several complications that occurred during and following attempted cryptorchidectomy. Inadvertent prostatectomy has been previously reported as a sequela of cryptorchidectomy (3–5), and repair requires anastomosis of the bladder neck to the proximal urethra. Urethral strictures are the most common complication requiring additional surgery following repair (6). In this case, however, the dog required an additional emergency surgery due to the formation of a suture-associated urethral plug, which resulted in complete urinary obstruction.
It was previously theorized that sutures were rapidly covered with epithelium when exposed to the bladder lumen, and that this decreased the risk of suture-related calculus formation (7). More recent studies, however, have demonstrated that suture material within the lumen may inhibit epithelialization and that this risk is increased in inflamed or necrotic bladders (8). Absorbable monofilament suture material is generally recommended over nonabsorbable suture material for urinary tract surgery to decrease the promotion of calculogenesis and the suture's potential to harbor bacteria and debris that may form a future crystal nidus (9–11).
The anastomosis performed during the initial urinary tract repair in this case was performed with 3-0 Polydioxanone (PDS). Polydioxanone is an absorbable monofilament suture that has 14% reduction in tensile strength at 14 d and 31% at 42 d with complete absorption occurring in 180 d (12). Monocryl is also an absorbable monofilament suture but undergoes a 40% to 50% reduction in tensile strength at 7 d and 70% to 80% at 14 d with complete absorption occurring at 90 to 120 d (12). We elected to use polydioxanone for the first surgery, given our concerns about the degree of tissue disruption and necrosis that was present. We were concerned that healing may be prolonged compared with a normal cystotomy on a relatively healthy bladder. Unfortunately, this decision likely contributed to the development of the struvite urolith plug, which ultimately resulted in complete urinary obstruction. We elected to close the defect during the second surgery using Monocryl (Polyglecaprone 25) to try and avoid the recurrence of crystal formation, given the previous polydioxanone suture-related urolithiasis. In addition, care was taken to avoid penetrating the lumen of the bladder while placing the sutures in an attempt to maintain the integrity of the bladder epithelium.
The use of Monocryl in bladder closures has been previously investigated. Greenberg et al (10) suggested that the tensile strength of monocryl in urine may be unacceptable by the critical healing time for bladder tissue; however, Hildreth et al (7) concluded that an appositional pattern using monocryl was acceptable for closure of the bladder wall, which may return to full strength in 14 to 21 d. The outcome of this case supports the findings of Hildreth et al (7), given that the patient recovered from the final surgery without any complications related to bladder healing. The authors routinely use monocryl in an appositional, non-penetrating suture pattern for bladder closures; however, we suggest that further research is required to evaluate its use in cases with severely devitalized bladder tissue and in cases with sterile versus infected urine.
In this case, the urethrotomy was converted to an urethrostomy because of concerns that additional uroliths may form in the future, and that financially, additional surgical procedures or extended hospital stays were not an option for the owner. In dogs, struvite uroliths may form secondary to a urinary tract infection with urease-producing microbes or in sterile urine (13,14). Medical therapy can be attempted to dissolve the struvite uroliths in non-emergency cases using a canned calculolytic diet that promotes acid urine, diuresis, restriction of phosphorus, and increased water consumption (15–17). Infection-induced struvite uroliths dissolved in an average of 12 wk in dogs when appropriate antimicrobials were given concurrently and sterile struvite uroliths dissolved in an average of 5 to 6 wk on this diet (18). Dietary modifications were suggested for this patient following the second surgery, and recheck visits with the referring veterinarian for urinalysis and cultures were recommended.
Urine dribbling was encountered immediately following the initial revision surgery in this case. Previous studies have demonstrated that decreased urethral pressures in the skeletal muscle of the external sphincter and detrusor instability contribute to incontinence in dogs post prostatectomy (19,20). In this case, it is assumed that the inadvertent prostatectomy resulted in interference with and resection of the prostatic urethra and associated neurovascular structures, resulting in the constant dribbling (22). The dog was ultimately treated with phenylpropanolamine, which appeared to resolve the incontinence. Phenylpropanolamine is a sympathomimetic that works by indirectly stimulating alpha and beta adrenergic receptors, resulting in an increased urethral sphincter tone and subsequent closure of the bladder neck (23).
This case represents several complications associated with cryptorchidectomy with which veterinary practitioners should be aware. Inadvertent prostatectomy is possible when the tissues in question are not adequately identified. Finding and tracing the ductus deferens to the retained testicle is recommended so that adjacent tissues are not mistakenly removed. In addition, care should be taken when performing urinary tract surgery; appropriate suture materials and techniques should be employed to minimize postoperative complications. CVJ
Footnotes
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References
1. Basinger RR, Rawlings CA, Barsanti JA, Oliver JE. Urodynamic alterations associated with clinical prostatic disease and prostatic surgery in 23 dogs. J Am Anim Hosp Assoc. 1989;25:385–392. [Google Scholar]
2. Basinger RR, Rawlings CA. Surgical management of prostatic diseases. Compend Contin Educ Vet. 1987;9:933–1000. [Google Scholar]
3. Yarrow TG. Inadvertent prostatectomy as a complication of cryptorchidectomy. J Am Anim Hosp Assoc. 1996;32:376–377. [PubMed] [Google Scholar]
4. Schulz KS, Waldron DR, Smith MM, Henderson RA, Howe LM. Inadvertent prostatectomy as a complication of cryptorchidectomy in four dogs. J Am Anim Hosp Assoc. 1996;32:211–214. [PubMed] [Google Scholar]
5. Bellah JR, Spencer CP, Salmeri KR. Hemiprostatic urethral avulsion during cryptorchid orchiectomy in a dog. J Am Anim Hosp Assoc. 1989;25:553–556. [Google Scholar]
6. Powers MY, Campbell BG, Weisse C. Porcine small intestinal submu-cosa augmentation urethroplasty and balloon dilatation of a urethral stricture secondary to inadvertent prostatectomy in a dog. J Am Anim Hosp Assoc. 2010;46:358–365. [PubMed] [Google Scholar]
7. Hildreth BE, III, Ellison GW, Roberts JF, et al. Biomechanical and histologic comparison of single-layer continuous Cushing and simple continuous appositional cystotomy closure by use of poliglecaprone 25 in rats with experimentally induced inflammation of the urinary bladder. Am J Vet Med Assoc. 2006;67:686–692. [PubMed] [Google Scholar]
8. Appel SL, Lefebvre SL, Houston DM, Homberg DL, Stone JEA, Moore AEP. Evaluation of risk factors associated with suture-nidus cystoliths in dogs and cats: 176 cases (1999–2006) J Am Vet Med Assoc. 2008;233:1889–1895. [PubMed] [Google Scholar]
9. Grier RL. Symposium on surgical techniques in small animal practice. Cystotomy. Vet Clin North Am Small Anim Pract. 1975;5:415–420. [PubMed] [Google Scholar]
10. Greenberg CB, Davidson EB, Bellmer DD, et al. Evaluation of the tensile strengths of four monofilament absorbable suture materials after immersion in canine urine with or without bacteria. Am J Vet Res. 2004;65:847–853. [PubMed] [Google Scholar]
11. Schiller TD, Stone EA, Gupta BS. In vitro loss of tensile strength and elasticity of five absorbable suture materials in sterile and infected canine urine. Vet Surg. 1993;22:208–212. [PubMed] [Google Scholar]
12. Fossum TW, Hedlund CS, Johnson AL, et al. Small Animal Surgery. 3rd ed. St Louis, Missouri: Mosby Elsevier; 2007. p. 60. [Google Scholar]
13. Houston DM, Moore AE. Canine and feline urolithiasis: Examination of over 50 000 urolith submissions to the Canadian veterinary urolith centre from 1998 to 2008. Can Vet J. 2009;50:1263–1268. [PMC free article] [PubMed] [Google Scholar]
14. Osborne CA, Klausner JS, Polzin DJ, Griffith DP. Etiopathogenesis of canine struvite urolithiasis. Vet Clin North Am Small Anim Pract. 1986;16:67–86. [PubMed] [Google Scholar]
15. Osborne CA, Lulich JP, Polzin DJ, et al. Canine urolithiasis Small Animal Clinical Nutrition. 4th ed. Topeka, Kansas: Mark Morris Institute; 2000. pp. 605–688. [Google Scholar]
16. Osborne CA, Polzin DJ, Kruger JM, Abdullahi SU, Leininger JR, Griffith DP. Medical dissolution of canine struvite uroliths. Vet Clin North Am Small Anim Pract. 1986;16:349–374. [PubMed] [Google Scholar]
17. Osborne CA, Klausner JS, Krawiec DR, Griffith DP. Canine struvite urolithiasis: Problems and their dissolution. J Am Vet Med Assoc. 1981;179:239–244. [PubMed] [Google Scholar]
18. Osborne CA, Lulich JP, Polzin DJ, et al. Medical dissolution and prevention of canine struvite uroliths: Twenty years experience. Vet Clin North Am Small Anim Pract. 1999;29:73–111. [PubMed] [Google Scholar]
19. Lulich JP, Osborne CA, Unger LK. Nonsurgical removal of urocystoliths by voiding urohydropulsion. J Am Vet Med Assoc. 1993;203:660–663. [PubMed] [Google Scholar]
20. Furlow WL. Postprostatectomy urinary incontinence. Etiology, prevention and selection of surgical treatment. Urol Clin North Am. 1978;5:347–352. [PubMed] [Google Scholar]
21. Barrett DM, Furlow WL. Radical prostatectomy incontinence and the AS791 artificial urinary sphincter. J Urol. 1983;129:528–530. [PubMed] [Google Scholar]
22. Goldsmid SE, Bellenger CR. Urinary incontinence after prostatectomy in dogs. Vet Surg. 1991;20:253–256. [PubMed] [Google Scholar]
23. Plumb DC. Plumb's Veterinary Drug Handbook. 5th ed. Mississauga, Ontario: Wiley-Blackwell; 2005. [Google Scholar]
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