Intestine: strangulated obstruction / hernia in Cats (Felis) | Vetlexicon
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Intestine: strangulated obstruction / hernia

ISSN 2398-2950


Introduction

  • Formed when a piece of bowel passes through a congenital or acquired defect in the abdominal wall, perineal musculature, mesentery or diaphragm.
  • Cause: acute or may occur after hernia has been present for a long time.
  • Signs: vomiting Vomiting, abdominal pain, anorexia, fever and depression.
  • Strangulation should always be considered in cases of suspected bowel obstruction where the clinical signs are more severe than those associated with a simple mechanical obstruction.
  • Diagnosis: radiography.
  • Treatment: surgical exposure of the hernial sac contents, breakdown of any adhesions and reduction of the bowel, and possibly resection and anastomosis.
  • Prognosis: guarded.

Acute presentation

  • Vomiting Vomiting.
  • Hematochezia.
  • Anorexia.
  • Abdominal pain or tenderness.
  • Shock Shock: septic, pale mucous membranes, slow capillary refill, tachycardia.

Pathogenesis

Pathophysiology

  • Luminal blockage as such is not always present but the blood supply to a segment of bowel is severely compromized.
  • An intact arterial supply allows the intramural sequestration of blood and eventually bowel wall edema.
  • The bowel will distend and become filled with gas and fluid proximal to the strangulation. The fluid in a strangulated obstruction will contain a significant amount of blood.
  • If the strangulation continues, the bowel wall will become non-viable and necrotic, allowing the transmural migration of toxins and bacteria. Fluid and blood loss combined with the peritoneal absorption of these bacteria and toxic substances will eventually lead to hypovolemia and endotoxic shock and death if left untreated.

Timecourse

  • Acute.

Diagnosis

Presenting problems

Client history

  • Acute onset.
  • Vomiting.
  • Hematochezia.
  • Anorexia.
  • Depression.
  • Presence of abdominal wall defect.

Clinical signs

  • Abdominal pain or tenderness.
  • Fever or hypothermia.
  • Depression.
  • Palpable abdominal mass.
  • Incarcerated bowel in a hernia that is palpated as a turgid painful mass with considerable inflammation and swelling to the surrounding tissues.
  • Shock, pale mucous membranes, slow capillary refill, tachycardia.

Diagnostic investigation

Radiography

  • See abdominal radiography Radiography: abdomen.
  • Presence of loops of intestine outside the peritoneal cavity.
  • Ileus of loops of intestine proximal to strangulation.

Contrast radiography

Confirmation of diagnosis

Discriminatory diagnostic features

  • History.
  • Clinical signs.

Definitive diagnostic features

  • Radiography.

Gross autopsy findings

  • Open thorax and abdomen. Inspect abdominal contents carefully and systematically in situ prior to any organ removal. Incarcerated bowel is typically markedly congested (dark red).
  • Be careful not to manually correct the displacement by careless examination.
  • Check carefully for predisposing factors such as neoplasia, other masses.
  • Note that intussusception is a common agonal change and so should be interpreted with caution. Congestion is obvious in prolonged gut displacements.

Histopathology findings

  • Affected bowel typically has marked congestion, and may have hemorrhage and necrosis depending on duration and severity.

Differential diagnosis

Treatment

Initial symptomatic treatment

Standard treatment

  • Surgery - laparotomy/celiotomy Laparotomy: midline, and resection and anastomosis:
    • Clip and prepare sufficient area to allow extension of incision if necessary.
    • Incise over hernia/rupture - extend to expose peritoneal cavity or perform separate incision.

    Many surgeons prefer a ventral midline incision if it is a traumatic hernia.

Monitoring

For shock, peritonitis

  • Temperature, pulse, respiration.
  • Abdominal pain.
  • Vomiting.

Prevention

Outcomes

Further Reading

Publications

Refereed papers