Blood patches may cause scarring in the epidural space: two case reports.

The use of epidural blood patches has become standard treatment for postdural puncture headache. Two cases suggest that there may occasionally be incomplete resorption of the blood patch, resulting in scarring in the epidural space that can be visualised using postpartum contrast injection and fluoroscopy. Both patients had a previous caesarean delivery during which they had suffered inadvertent dural punctures followed by epidural blood patches. When subsequently presenting for repeat caesarean delivery, both had inadequate epidural anaesthesia. Epidural insertion was then repeated, resulting in successful anaesthesia in one patient but a total subdural block with delayed apnoea and unconsciousness in the other. Distortion of epidural anatomy by fibrosis was considered to be a possible cause.