GASTROINTESTINAL VASCULAR DISORDERS
Ischemic bowel disease is the term used to describe the condition arising from insufficient blood flow to the gastrointestinal tract. Most pediatric cases of acute ischemic bowel disease result from extrinsic obstruction, hypercoagulable states, or hypovolemic shock. Ischemic injury is also thought to play a central role in the development of necrotizing enterocolitis. Clinical symptoms of ischemia may include colicky periumbilical pain, ileus, bilious vomiting, hematemesis, or hematochezia. Ischemic injury should be considered if symptoms occur following an acute event such as surgical obstruction or shock. Chronic vascular insufficiency may result in steatorrhea, protein-losing enteropathy, or carbohydrate malabsorption.
Diagnosis of ischemic bowel disease requires a high degree of suspicion after a thorough history and physical exam. Further studies to diagnose intestinal ischemia may include computed tomography (CT) of abdomen or Doppler ultrasound. In some instances, mesenteric angiography may be required. Endoscopic findings (Fig. 407-1) are easily misinterpreted as being due to inflammatory bowel disease, although mucosal biopsies will generally show acute inflammatory changes. Chronic ischemia may cause chronic changes and fibrosis. Treatment relies on addressing the underlying cause and may include resection of involved bowel, anticoagulation therapies, or interventional radiographic therapies.
Colonoscopic findings from a patient with bowel ischemia. Note the diffuse exudate; however, the mucosa can also appear cyanotic or necrotic. (Reproduced with permission from www.gastrolab.net.)
SYSTEMIC VASCULAR DISEASES
Systemic vascular diseases are the most common chronic or recurrent causes of bowel ischemia in children. Dermatomyositis can be associated with mesenteric vasculitis, and intestinal ulcerations and even perforations may occur. Gastrointestinal involvement in dermatomyositis is more common in pediatric patients than adult patients with the disease. Other vascular disorders, including polymyositis, and polyarteritis nodosa are occasionally associated with gastrointestinal ischemia causing obstruction, perforation, and hemorrhage. Systemic lupus erythematous can cause an arterial vasculitis and abdominal vessel thrombosis. Atrophic papulosis, also known as Degos disease, is a rare thrombo-occlusive vasculitis that affects small to medium-sized vessels and can affect multiple organ systems. It is not clear whether Degos disease is a single entity or the end stage of several vasculitic conditions. It may respond to treatment with eculizumab and treprostinil, a synthetic analog of prostacyclin (PGI2).
Henoch-Schönlein purpura (HSP) is an immune complex–mediated vasculitis affecting small vessels of the skin, joints, kidneys, and gastrointestinal tract, as discussed in detail in Chapter 200. Gastrointestinal symptoms of colicky abdominal pain, vomiting, hematemesis, diarrhea, and hematochezia may be observed several weeks or months before the onset of the typical palpable purpuric skin lesions. Gastrointestinal complaints are common, occurring in as many as 85% of patients. Involvement of the pancreatobiliary system has also been reported. Serious complications of intussusception, obstruction, or perforation are possible. Endoscopy ...