Case Report Inguinal Rupture with Herniation of the Urinary Bladder

EQUINE VETERINARY EDUCATION / AE / January 2010 3

Case Report Inguinal rupture with herniation of the urinary bladder

through the scrotal fascia in a Shetland pony foaleve_8195 3..6 M. Cousty*†, C. Tricaud, V. Picandet and O. Geffroy† Clinique Equine de Livet, Cour Samson, 14140 Saint Michel de Livet, France; and †École Nationale Vétérinaire de Nantes, La Chantrerie, 44307 Nantes, France.

Keywords: horse; hernia; urinary bladder; inguinal rupture; surgery

Summary Herniation of the urinary bladder has been reported through a congenitally enlarged inguinal canal in a cat Herniation of the urinary bladder in the inguinal region has (Zulauf et al. 2007) and in dogs (Bellenger 1996). Eversion of not previously been described in the horse. A case of the urinary bladder has been reported through the inguinal rupture with herniation of the bladder through the umbilicus in a foal (Textor et al. 2001) and the vagina in scrotal fascia in a 3-month-old Shetland pony, diagnosed mares (Squire et al. 1992). To our knowledge, herniation of by external palpation, urinary catheterisation and external the urinary bladder has not been reported in the inguinal ultrasonographic examination is reported. Surgical region in the horse. A case of inguinal rupture and management of the case was by dissection of the scrotal protrusion of the urinary bladder outside the vaginal sac in fascia, partial cystectomy and unilateral castration. During a Shetland Pony foal is described. the period of hospitalisation the only complication was a slight seroma, which resolved spontaneously. Follow-up Case history and clinical findings after 6 months did not reveal any abnormality. A 3-month-old male Shetland pony was examined for Introduction urinary incontinence, recurrent pollakuria and the presence of a scrotal mass. There was no history of dystocia. On physical examination, a fluctuant mass was Inguinal herniation (also commonly referred to as an present on the right side of the scrotum. The right inguinal indirect inguinal hernia) occurs when an abdominal ring was difficult to palpate; however, both testes were organ, usually small intestine, protrudes through the located in the scrotum. Urine was observed to drip from vaginal ring into the inguinal canal (Schneider et al. 1982; the penis each time pressure was applied to the mass. Cox 1988; Schumacher 2006). A ruptured inguinal hernia Ultrasound examination (Fig 1) revealed the presence of a occurs when an abdominal organ protrudes through the structure with a well-defined wall and anechoic contents, vaginal ring and then passes through a rent in the parietal lying in a subcutaneous position. However, it was not tunic and scrotal fascia to lie subcutaneously in the possible to determine if it was inside or outside the vaginal scrotum (van der Velden 1988; Schumacher 2006). An sac. On urinary catheterisation, the catheter was palpable inguinal rupture (also commonly referred to as a direct within the scrotal mass and after evacuation of urine the inguinal hernia) occurs when an abdominal organ passes mass was observed to decrease in size. The mass was not through a rent in the peritoneum and transverse fascia reducible by manual palpation. No abnormalities were adjacent to the vaginal ring such that the organ is found identified on routine haematology, serum biochemistry in a subcutaneous location adjacent to but outside of the and urine analysis. A diagnosis of herniation of the urinary vaginal process (Cox 1988; Schumacher 2006). Inguinal bladder was made. However, it was not possible to herniation and rupture occur more commonly in stallions determine if it was due to an inguinal herniation or an and foals and small intestine is the most commonly inguinal rupture. involved abdominal viscus (Schumacher 2006). Treatment

*Author to whom correspondence should be addressed. Dr Cousty’s present address: Unité de Chirurgie, Ecole Nationale Vétérinaire, Prior to surgery the foal received ceftiofur (2.2 mg/kg bwt Atlanpôle – La Chantrerie – BP 40706, 44307 Nantes Cedex 3, France. i.v.) and flunixin meglumine (1.1 mg/kg bwt i.v.). Following

sedation with romifidine (0.08 mg/kg bwt i.v.), anaesthesia was induced with ketamine (2.2 mg/kg bwt i.v.) and diazepam (0.2 mg/kg bwt i.v.) and maintained with isoflurane and an infusion of a romifidine-ketamine- butorphanol solution (romifidine 1 mg/kg bwt/min, ketamine 20 mg/kg bwt/min, butorphanol 0.6 mg/kg bwt/min). The foal was positioned in dorsal recumbency, the abdomen and inguinal region were clipped and a routine aseptic skin preparation was performed. A 15 cm incision was made over the right inguinal ring. The parietal layer of the vaginal tunic was carefully dissected from the surrounding fascia with Metzenbaum scissors and opened. The testis, epididymis and spermatic cord were present within the sac of the parietal layer of the vaginal tunic and no abnormality was observed. Palpation of the vaginal ring did not reveal the presence of any abdominal organ. Dissection was carefully continued outside the vaginal tunic to reveal the serosal surface of the apex of the Fig 1: Ultrasound examination of the right inguinal region showing the presence of an anechoic content with a well-defined wall. It urinary bladder between the internal spermatic fascia and was not possible to determine if it was inside or outside the vaginal the cremaster muscle. The urinary bladder was adherent to tunic. the scrotal fascia (Fig 2). The apex of the bladder was dissected free from the fascial attachments (Fig 3). However, the bladder wall was thickened and haemorrhagic, preventing replacement of the bladder into the abdominal cavity. Doyen intestinal forceps were placed across the bladder and the apex of the bladder was resected. The bladder wall was closed in 2 layers with 3 metric polydioxanone (PDS) in a simple continuous pattern oversewn by a Cushing pattern. Care was taken not to penetrate the lumen of the bladder. The bladder was then returned to the abdomen. The ipsilateral testis was resected following ligation and application of emasculators on the spermatic cord. The parietal layer of the vaginal tunic was closed with a transfixating ligature of 4 metric polyglactin 910 (Vicryl). The scrotal fascia was closed with 4 metric polyglactin 910 (Vicryl) in a cruciate pattern. The skin was closed with 3 metric PDS in a continuous pattern. Fig 2: Adhesion of the serosal surface of the apex of the urinary bladder to the scrotal fascia. Outcome

Following surgery the foal received ceftiofur (2.2 mg/kg bwt i.v. s.i.d.), gentamicin (6.6 mg/kg bwt s.i.d.) and flunixin meglumine (1.1 mg/kg bwt i.v. b.i.d.) for 5 days. The foal was carefully monitored after surgery and the only complication observed was a slight seroma deep to the skin incision which resolved spontaneously. The foal was discharged 5 days after surgery. On follow-up by telephone questionnaire 6 months after surgery the foal was growing as expected without evidence of urinary dysfunction.

Discussion

In horses, the most common organ involved in inguinal herniation is the small intestine (Schumacher 2006). To our Fig 3: Apex of the bladder after resection of the adhesion. knowledge, herniation of the urinary bladder has not been

reported in horses, although it has been reported in cats of the vaginal ring did not reveal the presence of any (Zulauf et al. 2007), dogs (Bellenger 1996) and man (Curr abdominal organ. For these reasons, the hernia can be et al. 1988; Schewe et al. 2000; Fuerxer et al. 2006; Tubbs considered as an inguinal rupture. The precise location of et al. 2007; Bisharat et al. 2009). the hernia is shown on Figure 4 according to the findings In this case, the urinary bladder had partially passed observed during the surgical procedure. through a rent in the peritoneum and transverse fascia, Ultrasonographic examination may be used in horses and was protruding between the internal spermatic fascia to differentiate between the possible causes of inguinal and the cremaster muscle. In horses, the elastic swelling (Blackford et al. 1992) and was very useful in this abdominal tunic that covers the external abdominal case. However, ultrasonography did not allow us to muscle gives rise the superficial inguinal ring and to the determine if the herniation was due to an inguinal external spermatic fascia. The transverse fascia that lines herniation or an inguinal rupture. Urinary catheterisation the internal surface of the abdominal muscle evaginates confirmed that the mass in the inguinal region was the as the internal spermatic fascia. The cremaster muscle bladder however other diagnostic techniques have originates from the internal abdominal muscle and is proved useful in other species. Air contrast radiography located between the external spermatic fascia and the has been used to confirm bladder involvement in an internal spermatic fascia (Budras et al. 2003). The parietal inguinal hernia in a cat (Zulauf et al. 2007) but we believe layer of the vaginal tunic was intact and no abnormalities that even in a foal this technique would prove difficult. In of the spermatic cord and testis were identified. Palpation human medicine a computed tomography scan can be performed after cystography with contrast medium (Fuerxer et al. 2006). In man, as in horses, an indirect hernia follows the spermatic cord in the inguinal canal. The canal communicates with the abdominal cavity through the abdominal ring. In man, a direct inguinal hernia is located over the pelvic bone always secondary to a weakness in the pectineal ligament (Fuerxer et al. 2006). However, in horses, the intestine passes through a rent and is not surrounded by peritoneum contrary to human cases. This condition is consequently more correctly called inguinal rupture, not hernia (Cox 1988; Schumacher 2006). The aetiology of direct hernia is supposed to be a weakness of connective tissue combined with an elevation of abdominal pressure (Schewe et al. 2000). Compression of the foal abdomen during parturition may be responsible for ruptured inguinal hernias (Spurlock and Robertson 1988; van der Velden 1988) and ruptured inguinal hernias are more common in foals than in mature horses (Schumacher 2006). In mature horses trauma is considered to lead to inguinal ruptures and such injuries are less common in foals than ruptured inguinal hernias (Cox 1988). As the animal affected in this report was aged only 3 months it is very likely that the rupture occurred during parturition. The wall of the urinary bladder at the apex was thickened and required resection to allow reduction of the bladder into the abdomen. Removal of this tissue may also have helped to prevent intra-abdominal adhesions to the damaged serosa of the bladder forming. Serosal lesions are also observed on the surface of the intestine during inguinal rupture or ruptured inguinal herniation as a result of adherence of the bowel to the subcutaneous tissues (Schumacher 2006). Resection of the apex of the urinary bladder has been recommended in human surgery if the Fig 4: Transverse plan of the inguinal area showing the precise protruding tissue is necrotic or incidental tumours are location of the hernia (red line). 1) Skin; 2) external spermatic present (Gomella et al. 1985; Thompson et al. 1986). fascia; 3) cremaster muscle; 4) internal spermatic fascia; In conclusion, this inguinal rupture with herniation of the 5) external abdominal oblique muscle; 6) superficial inguinal ring; 7) vaginal ring; 8) transverse fascia; 9) parietal peritoneum; 10) urinary bladder was successfully managed with partial vaginal process. cystectomy, closure of the rent and castration of the

ipsilateral testicle. Inguinal rupture with herniation of the Gomella, L.G., Spires, S.M., Burton, J.M., Ram, M.D. and Flanigan, R.C. urinary bladder is a condition that can be encountered in (1985) The surgical implications of herniation of the urinary bladder. Arch. Surg. 120, 964-967. foals. It can be diagnosed by physical examination, ultrasonography and urinary catheterisation, and treated Schewe, J., Brands, E.H. and Pannek, J. (2000) The inguinal bladder diverticulum: a rare differential diagnosis of hernias. Int. Urol. successfully with surgical reduction, which may include Nephrol. 32, 255-256. partial cystectomy. Schneider, R.K., Milne, D.W. and Kohn, C.W. (1982) Acquired inguinal hernia in the horse: a review of 27 cases. J. Am. vet. med. Ass. 180, Acknowledgement 317-320. Schumacher, J. (2006) Testis. In: Equine surgery, Eds: J.A. Auer and J.A. The authors would like to thank Thomas Hughes for the Stick, W.B. Saunders, St Louis. pp 775-810. revision of the manuscript. Spurlock, G.H. and Robertson, J.T. (1988) Congenital inguinal hernias associated with a rent in the common vaginal tunic in five foals. J. References Am. vet. med. Ass. 193, 1087-1088. Squire, K.R., Adams, S.B. and Conley, R. (1992) Postpartum partial Bellenger, C. (1996) Inguinal and scrotal herniation in 61 dogs. Aust. vet. cystectomy through the vagina in a mare with everted partially Pract. 26, 58-59. necrotic bladder. J. Am. vet. med. Ass. 200, 1111-1113.

Bisharat, M., O’Donnell, M.E., Thompson, T., Mackenzie, N., Kirkpatrick, Textor, J.A., Goodrich, L. and Wion, L. (2001) Umbilical evagination of D., Spence, R.A. and Lee, J. (2009) Complications of inguinoscrotal the urinary bladder in a neonatal filly. J. Am. vet. med. Ass. 219, 953- bladder hernias: a case series. Hernia 13, 81-84. 956, 939. Blackford, J.T., Toal, R.L. and Latimer, F.G. (1992) Percutaneous Thompson, J.E., Jr., Taylor, J.B., Nazarian, N. and Bennion, R.S. (1986) ultrasonographic diagnosis of suspected acquired inguinal and Massive inguinal scrotal bladder hernias: a review of the literature scrotal herniation in horses. Proc. Am. Ass. equine Practnrs. 37, 357. with 2 new cases. J. Urol. 136, 1299-1301. Budras, K., Sack, W. and Rock, S. (2003) Anatomy of the Horse. An Illustrated Text, 4th edn., Sclütersche, Hannover. p 135. Tubbs, R.S., Loukas, M., Shoja, M.M., Salter, E.G. and Oakes, W.J. (2007) Indirect inguinal hernia of the urinary bladder through a persistent Cox, J.E. (1988) Hernias and ruptures: words to the heat of deeds. canal of Nuck: case report. Hernia 11, 287-288. Equine vet. J. 20, 155-156. Curry, N.S., O’Connor, K.F. and Tubbs, C.O. (1988) Scrotal cystocele Van der Velden, M.A. (1988) Ruptured inguinal hernia in new-born colt diagnosed by computed tomography. Urol. Radiol. 9, 247-248. foals: a review of 14 cases. Equine vet. J. 20, 178-181. Fuerxer, F., Brunner, P., Cucchi, J.M., Mourou, M.Y. and Bruneton, J.N. Zulauf, D., Voss, K. and Reichler, I.M. (2007) Herniation of the urinary (2006) Inguinal herniation of a bladder diverticulum. Clin. imaging bladder through a congenitally enlarged inguinal canal in a cat. 30, 354-356. Schweizer Arch. Tierheilk. 149, 559-562.

nearest the barrel is at the appropriate notch. Rotate the plunger ring 1/4 turn to lock it in place and ensure it is locked. Make sure the severity. These trials included horses of various breeds and under different management conditions, and included horses in race or show horse’s mouth contains no feed. Remove the cover from the tip of the syringe, and insert the syringe into the horse’s mouth at the training, pleasure horses, and foals as young as one month. Horses enrolled in the efficacy trials were healthy animals confirmed to have interdental space. Depress the plunger until stopped by the knurled ring. The dose should be deposited on the back of the tongue or deep gastric ulcers by gastroscopy. In these field trials, horses readily accepted GASTROGARD Paste. There were no drug related adverse into the cheek pouch. Care should be taken to ensure that the horse consumes the complete dose. Treated animals should be observed reactions. 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Clinical signs in foals may include: bruxism (grinding of teeth), excessive salivation, colic, cranial abdominal tenderness, NADA 141-123, Approved by FDA Do not use in horses intended for human consumption. Keep this and all drugs out of the reach of children. In case of ingestion, contact a physician. Physicians may contact a poison control center for advice concerning accidental ingestion. anorexia, diarrhea, sternal recumbency or weakness. A more accurate diagnosis of gastric ulceration in horses and foals may be made if Caution ulcers are visualized directly by endoscopic examination of the gastric mucosa. Adverse Reactions Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Gastric ulcers may recur in horses if therapy to prevent recurrence is not administered after the initial treatment is completed. Use In efficacy trials, when the drug was administered at 1.8 mg omeprazole/lb (4 mg/kg) body weight daily for 28 days and 0.9 mg omeprazole/lb Description GASTROGARD Paste at 0.9 mg omeprazole/lb body weight (2 mg/kg) for control of gastric ulcers following treatment. The safety of (2 mg/kg)body weight daily for 30 additional days, no adverse reactions were observed. Chemical name: 5-Methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl) methyl]sulfinyl]-1H-benzimidazole. administration of GASTROGARD Paste for longer than 91 days has not been determined. Precautions Empirical formula: C17H19N3O3S. Molecular weight: 345.42. Structural formula: Maximal acid suppression occurs after three to five days of treatment with omeprazole. The safety of GASTROGARD Paste has not been determined in pregnant or lactating mares. Safety OCH Clinical Pharmacology 3 • GASTROGARD Paste was well tolerated in the following controlled efficacy and safety studies. H C CH Mechanism of Action: Omeprazole is a gastric acid pump inhibitor that regulates the final step in hydrogen ion production and blocks gastric 3 3 • In field trials involving 139 horses, including foals as young as one month of age, no adverse reactions attributable to omeprazole O OCH3 acid secretion regardless of the stimulus. Omeprazole irreversibly binds to the gastric parietal cell’s H+, K+ ATPase enzyme which pumps treatment were noted. hydrogen ions into the lumen of the stomach in exchange for potassium ions. Since omeprazole accumulates in the cell canaliculi and is • In a placebo controlled adult horse safety study, horses received 20 mg/kg/day omeprazole (5x the recommended dose) for 90 days. H irreversibly bound to the effect site, the plasma concentration at steady state is not directly related to the amount that is bound to the enzyme. The relationship between omeprazole action and plasma concentration is a function of the rate-limiting process of H+, K+ ATPase activity/ No treatment related adverse effects were observed. How Supplied turnover. Once all of the enzyme becomes bound, acid secretion resumes only after new H+, K+ ATPase is synthesized in the parietal cell • In a placebo controlled tolerance study, adult horses were treated with GASTROGARD Paste at a dosage of 40 mg/kg/day (10x the recommended dose) for 21 days. No treatment related adverse effects were observed. GASTROGARD® (omeprazole) Paste for horses contains 37% w/w omeprazole and is available in an adjustable-dose syringe. Each syringe (i.e., the rate of new enzyme synthesis exceeds the rate of inhibition). contains 2.28 g of omeprazole. Syringes are calibrated according to body weight and are available in boxes of 7 units or 72 units. Pharmacodynamics: In a study of pharmacodynamic effects using horses with gastric cannulae, secretion of gastric acid was inhibited in • A placebo controlled foal safety study evaluated the safety of omeprazole at doses of 4, 12 or 20 mg/kg (1, 3 or 5x) once daily for 91 days. Foals ranged in age from 66 to 110 days at study initiation. Gamma glutamyltransferase (GGT) levels were significantly elevated in horses Storage Conditions horses given 4 mg omeprazole/kg/day. After the expected maximum suppression of gastric acid secretion was reached (5 days), the actual secretion of gastric acid was reduced by 99%, 95% and 90% at 8, 16, and 24 hours, respectively. treated at exaggerated doses of 20 mg/kg (5x the recommended dose). Mean stomach to body weight ratio was higher for foals in the 3x Store at 68°F – 77°F (20-25°C). Excursions between 59°F – 86°F (15-30°C) are permitted. Pharmacokinetics: In a pharmacokinetic study involving thirteen healthy, mixed breed horses (8 female, 5 male) receiving multiple doses and 5x groups than for controls; however, no abnormalities of the stomach were evident on histological examination. Indications of omeprazole paste (1.8 mg/lb once daily for fifteen days) in either a fed or fasted state, there was no evidence of drug accumulation in the Reproductive Safety For treatment and prevention of recurrence of gastric ulcers in horses and foals 4 weeks of age and older. plasma when comparing the extent of systemic exposure (AUC0-∞). When comparing the individual bioavailability data (AUC0-∞, Cmax, In a male reproductive safety study, 10 stallions received GastroGard Paste at 12 mg/kg/day (3x the recommended dose) for 70 days. Dosage Regimen and Tmax measurements) across the study days, there was great inter- and intrasubject variability in the rate and extent of product No treatment related adverse effects on semen quality or breeding behavior were observed. A safety study in breeding mares has not For treatment of gastric ulcers, GASTROGARD Paste should be administered orally once-a-day for 4 weeks at the recommended dosage of absorption. Also, the extent of omeprazole absorption in horses was reduced by approximately 67% in the presence of food. This is been conducted. 1.8 mg omeprazole/lb body weight (4 mg/kg). For the prevention of recurrence of gastric ulcers, continue treatment for at least an additional evidenced by the observation that the mean AUC0-∞ values measured during the fifth day of omeprazole therapy when the animals were For More Information Please call 1-888-637-4251 and please visit our web site at www.gastrogard.com. 4 weeks by administering GASTROGARD Paste at the recommended daily maintenance dose of 0.9 mg/lb (2 mg/kg). fasted for 24 hours was approximately three times greater than the AUC estimated after the first and fifteenth doses when the horses were Marketed by: Merial Limited Directions For Use fed hay ad libitum and sweet feed (grain) twice daily. Prandial status did not affect the rate of drug elimination. The terminal half-life estimates Duluth, GA • GASTROGARD Paste for horses is recommended for use in horses and foals 4 weeks of age and older. The contents of one syringe will (N=38) ranged from approximately one-half to eight hours. 30096-4640 dose a 1250 lb (568 kg) horse at the rate of 1.8 mg omeprazole/lb body weight (4 mg/kg). For treatment of gastric ulcers, each weight Efficacy marking on the syringe plunger will deliver sufficient omeprazole to treat 250 lb (114 kg) body weight. For prevention of recurrence of gastric Dose Confirmation: GASTROGARD® (omeprazole) Paste, administered to provide omeprazole at 1.8 mg/lb (4 mg/kg) daily for 28 days, Merial Limited, a company limited by shares registered in England and Wales (registered number 3332751) with a registered ulcers, each weight marking will deliver sufficient omeprazole to dose 500 lb (227 kg) body weight. effectively healed or reduced the severity of gastric ulcers in 92% of omeprazole-treated horses. In comparison, 32% of controls exhibited office at PO Box 327, Sandringham House, Sandringham Avenue, Harlow Business Park, Harlow, Essex CM19 5QA, England, • To deliver GASTROGARD Paste at the treatment dose rate of 1.8 mg omeprazole/lb body weight (4 mg/kg), set the syringe plunger to the healed or less severe ulcers. Horses enrolled in this study were healthy animals confirmed to have gastric ulcers by gastroscopy. Subsequent and domesticated in Delaware, USA as Merial LLC. appropriate weight marking according to the horse’s weight in pounds. daily administration of GASTROGARD Paste to provide omeprazole at 0.9 mg/lb (2 mg/kg) for 30 days prevented recurrence of gastric ulcers US Patent: 4255431 and 5708017 • To deliver GASTROGARD Paste at the dose rate of 0.9 mg/lb (2 mg/kg) to prevent recurrence of ulcers, set the syringe plunger to the in 84% of treated horses, whereas ulcers recurred or became more severe in horses removed from omeprazole treatment. Copyright © 2005 Merial Limited. weight marking corresponding to half of the horse’s weight in pounds. Clinical Field Trials: GASTROGARD Paste administered at 1.8 mg/lb (4 mg/kg) daily for 28 days healed or reduced the severity of gastric All rights reserved. Rev. 08-2005 • To set the syringe plunger, unlock the knurled ring by rotating it 1/4 turn. Slide the knurled ring along the plunger shaft so that the side ulcers in 99% of omeprazoletreated horses. In comparison, 32.4% of control horses had healed ulcers or ulcers which were reduced in ®GASTROGARD is a registered trademark of the AstraZeneca Group of Companies.