[Experience with the lateral lumbar approach in epidural anesthesia]

Based on a detailed analysis of X-ray pictures of the lumbo-sacral spine and experience assembled during epidural anaesthesia in 116 men, mean age 67 years, and 84 women, mean age 68 years, the authors describe in more detailed the formerly recommended method of a lateral lumbar approach. To make it as successful and as safe as possible it is essential during puncture to be aware of the typical resistance of the yellow ligament, frequently after previous contact with bone and to obtain the positive sign of the "hanging drop" after penetration of the ligament. If in exceptional instances in the depth the elastic resistance of the yellow ligament is lacking before the positive sign of the "hanging drop", it is better to perform the puncture of the epidural space in another intervertebral space. This practically rules out the false positive sign of the "hanging drop" in case of the possible presence of a tougher ligamentous septum in the paravertebral muscles in older patients. This rules out also the even rarer possible penetration of the needle to the dura mater, exactly in the middle of the yellow ligament through the opening for the blood vessel where are only individual elastic fibres, practically without resistance, with a positive "hanging drop".