Specific Complications and Problems With the Technique

Venous puncture
The area is richly vascularized (ascending lumbar vein). The position of the needle is too median -- it is necessary to direct the needle 5° more laterally.

Urethral Puncture
Too deep insertion of the needle.
Puncture of the kidney
Too deep and too cephalic puncture. Risk increased at the time of a puncture in L3
     on the right side.

Intraperitoneal injection
Insertion of the needle is too deep

Extension of anesthesia to epidural space
This is really not a true complication because analgesia will be effective. This obser-
     vation implies the modification of the protocol of injection and monitoring. The
     figure demonstrates the spread of a radio contrast material into the epidural
     (peridural) space.

Hematoma of the psoas muscle with a nerve compression

Tips:
Osseous contact: Transverse process
     This is a very welcome contact and a safety guard. The anatomical studies 10 show that the distance
     between the posterior edge of the transverse process and the plexus is rather constant and ranges
     between 15 and 20 mm. This is also confirmed by clinical studies 11. The needle is reorientated outwards
     to pass process in caudal direction. The depth of the progression beyond the process should not exceed
     20 mm. If the stimulation of a branch is not obtained it is necessary to withdraw and reorientate the
     needle direction.