Idiopathic Infantile Arterial Calcifications

Jorge I López Martínez

Idiopathic Infantile Arterial Calcifications

Introduction  For

many years idiopathic infantile arterial calcification was a disease that most likely was not diagnosed until after death  Among the cases that were diagnosed before death, radiographs have provided the most pertinent information to obtain the diagnosis

Description  Idiopathic

infantile arterial calcification is a diffuse disease of elastic and muscular arteries characterized by destruction and fragmentation of the arterial internal elastic membrane, deposition of calcium along the internal elastic membrane and intimal proliferation.  Prognosis is very poor. Most die before reaching one year of age.

Muscular Artery

Description (cont.)  Idiopathic

infantile arterial calcification is a rare disorder.  The etiology of this disease is unknown, although a few hypotheses have been presented:  1) hereditary disorder of connective

tissue  2) injury to or defect of the endothelium  3) altered iron metabolism  4) hemodynamic disturbance

2-week-old boy w/ IIAC 2-week-old boy w/ IIAC Axial image near superior mesenteric artery origin shows target appearance; wall calcification and lumen enhancement are separated by thickened intima.

2-week-old boy w/ IIAC 2-week-old boy w/ IIAC Coronal reformation shows progressive distal narrowing of aorta.

Pathogenesis  Two

theories exist as to the pathogenesis of the disease:  1) calcification of the internal elastic

membrane is the primary lesion, and intimal proliferation is secondary  2) intimal proliferation is the primary lesion, and calcifications are secondary and of less significance.  In either case, intimalproliferation usually leads to occlusion of the artery.

 The

coronary arteries are most commonly involved; in most cases, death is usually due to congestive heart

Coronary Artery Calcifications  Calcium

phosphate (hydroxyapatite, Ca3[-PO4]2-xCa[OH]2), which contains 40% calcium by weight, precipitates in diseased coronary arteries by a mechanism similar to that found in active bone formation and remodeling. Electron microscopic evidence supports the theory by which hydroxyapatite, the predominant crystalline form in calcium deposits, is formed primarily in vesicles that pinch off from arterial wall cells, analogous to the way matrix vesicles pinch off from chondrocytes in

Related Anomalies  Hydronephrosis  Polycystic  Trisomy

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 Trisomy

18

Kidneys

Consequential Anomalies  Prenatal  Hydrops

 Infancy  Pulmonary & Cardiac Failure  Renal Infarction  Peripheral Gangrene  Bowel Infarction

Treatments  Thyroid

extract

 Estrogens

and steroids

 Diphosphonates