Patient positioning for microdiscectomy nearly fatal because of iatrogenic obstruction to inferior cardiac inflow caused by hepatic hernia.

A routine microdiscectomy was complicated by an inferior cardiac inflow obstruction caused by compression of the inferior vena cava. This was due to further upward migration of an existing hepatic hernia through a right-sided diaphragmatic defect. Understanding the pathogenesis of this problem allowed the surgical team to adjust the positioning of the patient. After installing the patient on a different frame, the prone position was well tolerated and the microdiscectomy could be performed without the need to repair the diaphragmatic hernia.