Acquired Chiari type I malformation managed by expanding posterior fossa volume and literature review

Abstract

Purpose: The acquired Chiari type I malformation is a rare late complication of supratentorial shunting in children which is often accompanied by abnormal cranial vault thickening. Several surgical treatments for this disease have been proposed including supratentorial skull enlarging procedures and subtentorial craniotomy. But there is still debate about the best treatment strategy for this disease. Method and results: We reviewed the current knowledge of this disease in the paper. We illustrated one patient of symptomatic acquired Chiari type I malformation who had cysto-peritoneal (C-P) shunting and ventriculoperitoneal (V-P) shunting. We observed the CSF flow dynamic of this patient at different periods. The acquired Chiari type I malformation disappeared on imaging after thinning the occipital planum combined with the standard surgical therapy of Chiari decompression. The symptoms of the patient were relieved after surgery. Conclusion: Overshunting manifestations require prompt recognition and management. Preventive measures should be taken which include making a stringent selection of cases being considered for surgery, avoiding C-P drainage, and placing of a programmable valve as initial treatment of intracranial arachnoid cysts (AC) if shunting is considered.