[The visualisation of dura perforation and blood patches with ultrasound]

The postdural puncture headache (PDPH) is a possible complication after spinal or epidural puncture. The therapeutic concept is usually organised step by step, but the epidural blood patch is the most reliable and effective therapy. In earlier studies myelographie, epidurographie and MRT were used, to visualise the localisation of the dural defect and to describe the effects of patching the epidural space. Our working group focused on the utilisation of ultrasound and we decided to use this technique for the visualisation of bloodpatches. With agreement of the local ethics committee we monitored the performance of 4 epidural bloodpatches in pregnant women, who suffered from PDPH. We used a General Electric LQ 400 ultrasonograph with a 7-MHz-probe. To ensure sterile conditions we used sterile ultrasound sleeves and sterile ultrasound gel. In 3 of 4 cases a continuity loss could be represented in the doppel layer signal of the dura. It had the size of the diameter of a Tuohy needle. In one case the defect of the dura was larger than in the preliminary investigations (2,5 - 3 mm). The ultrasonography of the epidural space was performed in the paramedian scan. All patches were placed by using the conventional loss of resistance technique with using online ultrasound support. The epidural puncture and the application of the blood patches were visualised simultaneously in all cases. With the injection of blood a brief expansion of the epidural space was seen. The patients recieved a mean injection volume of 17 ml sterile blood. 10 to 40 seconds after the injection of blood the disconituity of the dura doppel layer signal was no longer provable. Within a short time we could detect the increase of cerebrospinal fluid and the patients headache was treated sucessfully. The clinical use of this diagnostic technique can be found in the simultaneous presentation of the dura leakage and the intervention while performing an epidural bloodpatch. Since these informations are relevant for further clinical practice further investigations are warranted.