A Practical Review of Perineural Versus Intraneural Injections

Histological confirmation of needle tip position during ultrasound-guided interscalene block: a randomized comparison between the intraplexus and the periplexus approach

“…Nevertheless, avoidance of ''intraneural injection'', which is defined by injection below the epineurium, is standard practice within the regional anesthesia literature. 3,5,13,23 Nerves cannot be dissected and removed in live patients, while comparing block techniques requires thousands of patients due to the low but clinically significant rate of neurological complications. 24 We chose the cadaver model followed by microscopic assessment of tissues in an attempt to clarify exactly which neural layers are penetrated with an intraplexus vs a periplexus approach.…”

“…1,2 This may be due to the limitation of conventional ultrasound to distinguish muscle fascia from epineurium and small fascicles, [3][4][5] such that mechanical nerve injury, barotrauma, or local anesthetic toxicity may result from unintended injection into critical nerve structures. 1,[6][7][8][9][10] This has recently led investigators to focus on how best to avoid nerves while still achieving a reliable block.…”

Ultrasound-guided regional anesthesia for upper limb surgery

“…This has been accomplished using real-time observation of the distribution of the injected solution correlated with the characteristics of the blocks it produced, particularly onset time and depth of block. 21 Macroanatomy, superficial landmarks, and the concept of a perineural sheath have now given way to an understanding of nerve microanatomy and its relationship to neighbouring tissue. The literature to determine the optimal technique with respect to ease of execution, reproducibility, reliability, speed of onset, and safety is still evolving.…”

“…L'observation en temps réel de la diffusion des solutions injectées corrélée avec les caractéristiques des blocs obtenus, notamment en ce qui a trait à la vitesse d'installation et la profondeur du bloc, ont permis de définir certains compartiments à cibler lors de la réalisation des blocs échoguidés. 21 La macroanatomie, les repères de surface et le concept de gaine périnerveuse ont maintenant fait place à la compréhension de la microanatomie nerveuse et de sa relation avec les tissus avoisinants. La littérature est encore en constante évolution pour déterminer quelle est la meilleure technique en regard de la facilité d'exécution, la reproductibilité, la fiabilité, la rapidité d'installation et la sécurité.…”

Permanent upper trunk plexopathy after interscalene brachial plexus block

“…Although the intraneural injection is not usually associated with ongoing nerve damage in many cases, the degree of damage will depend on the nerve structure affected, the brachial plexus being of particular importance. There are no clinical algorithms in place that can assist in monitoring how peripheral nerve blocks are performed in order to prevent neural injuries [10]. We report the case of a patient who suffered a severe neurological deficit after an IBPB.…”