Abdominothoracic anomalies accompanying central nervous system anomalies in TYPE 2 chiari malformation

Chiari Malformations are complex structural disorders caused by the herniation of the hindbrain structures from the foramen magnum to the upper spinal canal at varying degrees. Each type of Chiari malformation presents with associated conditions or anomalies. It is known that type 2 Chiari malformation, which is the subject of the research, is associated with neural tube closure defect and generally lumbar myelomeningocele. Malformation has been investigated in many aspects, and its pathological variations have been tried to be explained by theories. In this study, it was aimed to define the incidence of abdominothoracic anomalies outside the central nervous system in patients diagnosed with type 2 Chiari using the database of Fırat University Hospital and to determine the relationship between them, if any. The radiological examinations of 245 patients diagnosed with type 2 Chiari malformation between 2011 and 2021, registered in the Fırat University Hospital information system, were reviewed. Images of 76 patients were excluded from the study because they were not of sufficient quality, and thoracic-abdominal computed tomography and magnetic resonance images of the remaining 169 patients were re-evaluated for accompanying anomalies. In a total of 169 patients with Chiari, rib (28.4%) and renal (9.4%) anomalies were found to increase significantly, while other thoracoabdominal anomalies were found to be at an acceptable level (In the general population, rib anomalies were reported between 5% and 14%, and all urinary system anomalies were reported between 1% and 3.5%). When the relationship between these anomalies and spinal defect levels was investigated, although rib anomalies had a significant correlation with thoracolumbar-thoracolumbosacral defect (p<0.05), no correlation was found in renal anomalies. Apart from dysraphism, additional spinal anomalies (vertebra segmentation-formation anomalies, diastematomyelia, syringohydromyelia) frequently accompany our cases, all of whom have myelomeningocele. A strong statistical correlation was found between vertebra segmentation-formation anomalies and spinal defect levels (p<0.001). In addition, there was a significant increase in the frequency of femur fractures (10.1%) and developmental hip dysplasia (5.9%), which are important causes of morbidity in type 2 Chiari cases. Keywords: Chiari malformation, myelomeningocele, rib anomaly, horseshoe kidney