RELATO DE CASO: SIRENOMELIA ASSOCIADA A DEFEITOS CONGÊNITOS RAROS

Abstract

ABSTRACT

Introduction: Sirenomelia is a rare congenital anomaly that affects the formation of the lower limbs, usually paired by a single limb at the midline level, is usually associated with defects in the genitourinary tract. Case report: A case of necropsy of a newborn with an ultrasonographic diagnosis of sirenomelia who died minutes after birth. Among the postmortem findings, the following stand out: malformations of the genitourinary and colonic system, incomplete formation of the lumbosacral spine, aortic vascular deformity, pulmonary hypoplasia and signs of acute fetal distress, which presented with a single lower limb composed of partially fused femurs and a single fibula. The final diagnosis was Sirenomelia - type IV of the Stocker-Heifetz classification. Discussion: The pathophysiology of sirenomelia is not well defined, however two hypotheses that are considered in the literature: vascular and blastogenic. The first proposes that the presence of an aberrant single umbilical artery causes poor arterial irrigation in the lower portion of the fetus; resulting in an underdevelopment that characterizes sirenomelia. Blastogenic, explains the disease as a primary defect during the final phase of gastrulation, in which there is failure of the caudal somites and the caudal button. Conclusion: Sirenomelia is often associated with other congenital defects, affecting the formation of urogenital and gastrointestinal viscerals, such as unilateral or bilateral renal agenesis, absence of external genitalia, anorectal atresia and aberrant arterial abdominal vascularization. Malformations present in essencial organs are crucial for the newborn's prognosis and survival.

KEY-WORDS: Congenital Abnormalities; Musculoskeletal abnormality; Sirenomelia