Complications: Selective Nerve Root Blocks

Complications

Selective nerve root blocks are not associated with complications provided that they are performed carefully and accurately. The only true, but remote, complications are those of infection and allergic reactions associated with any procedure involving the injection of contrast medium or local anaesthetic.

The foremost hazard of selective nerve root blocks is striking the target nerve, but this is avoided by approaching the target point carefully and accurately The spinal nerve or dorsal root ganglion can be incurred only if the needle strays caudally. To guard against misadventure, the needle should be introduced slowly and under repeated fluoroscopic monitoring. Under these conditions, should the needle tip strike the nerve it can be promptly withdrawn before it pierces the nerve; thereafter its course can be corrected. This way, the risk of damaging the nerve is reduced or eliminated.

These precautions also guard against inadvertent dural puncture. Provided the needle is directed into the "safe triangle," it should not pierce the dural sleeve. Furthermore, the injection of contrast medium should reveal whether or not the dura has been pierced. The demonstration of intrathecal spread of contrast medium warns against injecting subsequent agents into the subarachnoid space and calls for repositioning of the needle.