Vascular, Systemic, and Other Disorders Affecting the Gastrointestinal Tract
Grzegorz Telega, Vincent F. Biank, and B U.K. Li
GASTROINTESTINAL VASCULAR DISORDERS
ISCHEMIC BOWEL DISORDERS
Ischemic bowel disease is the term used to describe disorders that cause insufficient blood flow to the gastrointestinal tract. (Table 412-1).1 Arteriosclerotic vascular disease is the major cause of ischemic bowel disease in adults but is extremely rare in children. Most pediatric cases of acute childhood ischemic bowel disease result from extrinsic obstruction, hyper-coagulable states, or following hypovolemic shock.2
Clinical findings with mesenteric vascular insufficiency consist of postprandial colicky periumbilical pain, with symptoms that are far worse than would be expected from physical examination of the abdomen. Similar symptoms can also be experienced with ischemia of the spleen or omentum. Acute vascular insufficiency results in nonspecific findings including ileus, bilious vomiting, and mucosal necrosis with hematemesis or hematochezia. Symptoms may worsen following reperfusion. Ischemic injury should be considered if symptoms persist or worsen following an acute insult such as shock or surgical obstruction. Chronic vascular insufficiency may result in protein-losing enteropathy, steatorrhea, or carbohydrate malabsorption.
Diagnosis of ischemic bowel disease or other vascular disorders of the bowel requires a high degree of suspicion and is mainly dependent upon the history and physical examination.3 Confirmatory studies may include gastric tonometry, Doppler ultrasound, and abdominal computerized tomography (CT). In some cases, mesenteric angiography may be necessary to establish the diagnosis. Due to the rarity of ischemic disease in childhood, endoscopic findings (see eFig. 412.1 ) of exudate are often misinterpreted as being due to inflammatory bowel disease. Biopsy generally shows acute inflammatory changes. Chronic ischemia may be associated with fibrosis. Treatment depends upon the underlying cause and may include resection of involved bowel, anticoagulation therapies, and interventional radiographic therapies.
Rarely, symptoms similar to ischemic bowel disease result from mesenteric venous inflammation. Mesenteric inflammatory venoocclusive disease is characterized by extended thrombophlebitis and fibrous organized thrombosis of multiple veins, not the arteries.4 Diagnosis is usually made on pathology of bowel resected for ischemia.
SYSTEMIC VASCULITIC DISEASES
Systemic vasculitic diseases (especially polyarteritis nodosa), anatomical malformations of the mesenteric artery, degas disease, and dermatomyositis are the most common chronic or recurrent causes of bowel ischemia in children.2Dermatomyositis can be associated with mesenteric vasculitis, intestinal ulcerations, and perforations. Other collagen vascular disorders, including polymyositis, polyarteritis nodosa, and systemic lupus erythematosus, are occasionally associated with mesenteric arteritis. Degos disease is an obliterative endarteritis that affects small to medium-sized vessels and can be associated with spontaneous perforation of the bowel.
Henoch-Schönlein purpura is a systemic vasculitis with deposition of IgA immune complexes in postcapillary venules throughout the body, as discussed in detail in Chapter 472. Gastrointestinal symptoms of diffuse abdominal pain, vomiting, and hematochezia may be observed several weeks before onset of the palpable purpuric skin lesions. Endoscopy displays purpuric lesions of the small bowel and colon.5 Intussusception occurs in approximately 10% of children with Henoch-Schönlein purpura and abdominal pain; bowel perforation and development of bowel stricture are less common. Pancreatitis and cholecystitis have been reported. Corticosteroid treatment may decrease the severity of GI symptoms, but treatment may mask symptoms of perforation and does not prevent renal complications. The benefits of corticosteroid treatment remain controversial.
Vascular malformations are a rare cause of painless bleeding of varying severity in children. Angiodysplasias are small vascular malformations of the gut. The lesions are often multiple and frequently involve the cecum or ascending colon, although they can occur at other places. In childhood, these are most commonly associated with Turner syndrome6 or von Willebrand’s syndrome.7 Diagnosis of angiodysplasia is often accomplished with endoscopy. Treatment options include endoscopic interventions (including double-balloon enteroscopy and ablation therapy), estrogen/progesterone therapy, or occasionally surgery.
Mass lesions involving mesenteric artery
Hemolytic uremic syndrome