Related Experiment Video
Updated: Jun 17, 2026

Nerve Stimulator-guided Injection of Autologous Stem Cells Near the Equine Left Recurrent Laryngeal Nerve
Published on: September 26, 2018
Nerve injury by needle nerve perforation in regional anaesthesia: does size matter?
T Steinfeldt1, W Nimphius, T Werner
1Department of Anaesthesiology and Intensive Care Therapy, Philipps University Marburg, Baldingerstr., 35032 Marburg, Germany. steinfeldt@gmx.de
Background:
In regional anaesthesia, there is a risk of direct nerve injury. The purpose of this study was to determine whether the diameter of the applied needle is associated with the magnitude of nerve injury after needle nerve perforation.
Methods:
In five anaesthetized pigs, the brachial plexus were exposed bilaterally. Up to eight nerves underwent needle nerve perforation using a 24 G pencil-point cannula (small diameter) or a 19 G pencil-point needle (large diameter). After 48 h, the nerves were resected during anaesthesia. The specimens were processed for visual examination and the detection of inflammatory cells, myelin damage and intraneural haematoma. The grade of nerve injury was scored ranging from 0 (no injury) to 4 (severe injury).
Results:
Forty-eight nerves were examined. The applied injury score was significantly lower in the small-diameter group [median (inter-quartile range) 2.0 (2.0-2.0)] compared with the large-diameter group [3.5 (3.0-4.0) P<0.01]. Myelin damage and intraneural haematoma occurred predominantly in the large-diameter group. Signs of post-traumatic regional inflammation were comparable among both groups.
Conclusions:
The severity of nerve injury after needle nerve perforation was related to the diameter of the applied cannula. However, no such difference exists for regional inflammation. Functional consequences of these findings need to be determined. Currently, small-diameter cannulae may be advisable for peripheral nerve blocks to minimize the risk of nerve injury in the case of nerve perforation.
Related Concept Videos
Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia
One of the advantages of...
Local Anesthetics: Differential Sensitivity of Nerve Fibers
Local Anesthetics: Adverse Effects
Once absorbed into the systemic circulation, local anesthetics can affect the organs that depend on the functioning of sodium...
Local Anesthetics: Clinical Application as Spinal Anesthesia
Local Anesthetics: Clinical Application as Surface, Infiltration, and Conduction Block Anesthesia