Canis ISSN: 2398-2942

Bladder: herniation

Contributor(s): Rachel Burrow

Introduction

  • Displacement occurs in 3 sites:
    • Perineal.
    • Inguinal.
    • Pre-pubic (associated with traumatic rupture of the cranial pubic ligament or the caudoventral body wall).
  • Signs: urethra may become obstructed - urinary tenesmus, or herniation of the bladder may be asymptomatic. A mass/swelling will be present at the site of the hernia, this swelling may fluctuate in size.
  • Diagnosis: history, clinical signs, radiography.
  • Treatment: surgical correction of the hernia.
  • Prognosis: good if early treatment.

Pathogenesis

Etiology

  • Displacement of the bladder to an extra-abdominal position occurs when there is a congenital or acquired weakness or enlargement of the inguinal ring (as with an inguinal hernia), acquired loss of support of the perineal diaphragm (as with a perineal hernia), or traumatic disruption of the caudoventral body wall (as with rupture of the cranial pubic tendon and/or body wall).

Pathophysiology

  • A loss/failure of the local structures that define the limits of the abdomen will allow local abdominal organs and abdominal organs that are freely mobile, to move through the defect, outside the limit of the abdomen. In the case of perineal and inguinal hernias and traumatic ruptures of the caudal abdominal wall, the bladder is local to the defect and may herniate.
  • Herniation of the bladder to a location other than its normal position in the caudoventral abdomen can result in a partial or complete obstruction to urine flow through kinking or twisting of the urethra. The bladder may be displaced (in inguinal and perineal hernias, and traumatic body wall ruptures) or retroflexed (in perineal hernias).
  • In the case of traumatic rupture of the caudal body wall and avulsion of the cranial pubic ligament there may be severe damage (shredding, tearing, etc) of the local tissues, in addition to cardiovascular instability, respiratory and orthopedic injuries.
  • The consequences of urethral obstruction due to herniation of the bladder are the same as those that occur with a physical urethral obstruction. The patient will become azotemic, and if the obstruction is not relieved, uremic and hyperkalemic. Devitalization or rupture of the bladder wall is possible associated with over-distension of the bladder with urine. Death usually occurs within 60-75 hours if a complete obstruction of the urethra is not treated.
  • If the bladder has been acutely (acute complete urethral obstruction) or chronically over-distended (partial urethral obstruction) it may become atonic through neuromuscular damage and the patient will then suffer from urinary retention and overflow incontinence.

Timecourse

  • The patient may present with herniation of the bladder shortly after development of the hernia, or weeks-months later.
  • If the obstruction of the urethra is complete, the development of clinical signs will develop acutely. The presentation may be less acute if the urethral obstruction is incomplete.
  • Occasionally bladder herniation may occur chronically and asymptomatically.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Brissot H N, Dupre G P & Bouvy B M (2004) Use of laparotomy in a staged approach for resolution of bilateral or complicated perineal hernia in 41 dogs. Vet Surg 33 (4), 412-421 PubMed.
  • Hosgood G, Hedlund C S, Pechman R D & Dean P W (1995) Perineal herniorrhaphy: perioperative data from 100 dogs. JAAHA 31 (4), 331-342 PubMed.

Other sources of information

  • Read R A, Bellenger C R (2003) Hernias. In: Slatter D (ed) Textbook of Small Animal Surgery, 3rd edn, Philadelphia: W B Saunders, pp 446-448.
  • Smeak D D (2003) Abdominal hernias. In:Slatter D (ed) Textbook of Small Animal Surgery, 3rd edn, Philadelphia: W B Saunders, pp 449-470.
  • Bellenger C R, Canfield R A (20023) Perineal hernia. In: Slatter D (ed) Textbook of Small Animal Surgery, 3rd edn, Philadelphia: W B Saunder, pp 487-498.
  • Waldron R A (2003) The bladder. In: Slatter D (ed) Textbook of Small Animal Surgery, 3rd edn, Philadelphia: W B Saunder, pp 1629-1637.


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