Article

Structural Injury to the Human Sciatic Nerve After Intraneural Needle Insertion

Departments of Anesthesiology, Hospital Clínic of Barcelona, Spain.
Regional anesthesia and pain medicine (Impact Factor: 2.12). 05/2009; 34(3):201-5. DOI: 10.1097/AAP.0b013e31819a2795
Source: PubMed

ABSTRACT Recent clinical reports suggest that intraneural needle placement may not always lead to neurologic injury. To explain the absence of neurologic complications in these reports, we studied the risk and extent of nerve injury after intentional needle-nerve placement in a cryopreserved human sciatic nerve.
The sciatic nerve was dissected from a cryopreserved cadaver through partial exposure. Needles were inserted through the nerve, using blunt-tip (30 degrees beveled) (group A) and sharp-tip (15 degrees beveled) (group D) needles. Five needle insertions were made for each needle type. Subsequently, transverse nerve sections at 10 needle trajectories were processed. Nerve samples were stained with hematoxylin-eosin, Masson trichromic, and immunohistochemical stains. In each section, the following variables were quantified: total number of fascicles and vessels in the immediate vicinity of the needle trajectories and the number of injured fascicles and vessels.
A total of 520 fascicles were quantified, of which 134 were in contact with the needle trajectories. The numbers of fascicles and vessels per section were 65 +/- 8 and 14 +/- 7, respectively. A mean of 16 +/- 5 fascicles were found in contact with the needle trajectory (group A: 17+/- 3, group D: 15 +/- 6). Of these, 4 fascicles (3.2%) and 1 intraneural vessel were found damaged in group D. No fascicular or vascular injuries were found in group A.
Our findings suggest that intraneural needle insertion may more commonly result in interfascicular rather than intrafascicular needle placement.

0 Followers
 · 
135 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The observation of high energy cosmic gamma rays with an energy threshold of 15 GeV using the proposed MAGIC ground based air imaging Cherenkov telescope requires the development of new low noise fast preamplifiers for the camera photosensors. The speed and noise performance of a transimpedance preamplifier that resolves the multi photoelectron peaks from a hybrid photomultiplier with a peaking time below 7 ns is presented. The new front-end circuit is designed with RF low noise bipolar transistors and provides fast output pulses that allow for fast trigger settings
    IEEE Transactions on Nuclear Science 09/1999; DOI:10.1109/23.790681 · 1.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent reports of painless intraneural injection of low volumes of local anesthetic without subsequent neurological deficit have led to the suggestion that deliberate subepineural injection may be a safe and therefore acceptable practice. This report describes a case where a venous cannulation needle inadvertently penetrated a patient's median nerve. Sudden onset severe lancinating pain occurred in the median nerve sensory distribution. A subsequent thorough ultrasound examination showed the median nerve to be located immediately posterior to the targeted median cubital vein. New onset sensory symptoms (numbness, tingling, pain, and altered sensation to touch) in the distribution of the penetrated median nerve persisted for >6 weeks. This report highlights the hazards of intraneural needle placement irrespective of an associated injection.
    Canadian Anaesthetists? Society Journal 09/2009; 56(12):935-8. DOI:10.1007/s12630-009-9200-0 · 2.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In sciatic nerve (SN) blocks, differences are seen in risk of nerve damage, minimum effective anesthetic volume, and onset time. This might be related to differences in the ratio neural:nonneural tissue within the nerve. For the brachial plexus, a higher proximal ratio may explain the higher risk for neural injury in proximal nerve blocks. A similar trend in risk is reported for SN; however, equivalent quantitative data are lacking. The authors aimed to determine the ratio neural:nonneural tissue within SN in situ in the upper leg. From five consecutive cadavers, the region between the sacrum and distal femur condyle was harvested and frozen. Using a cryomicrotome, consecutive transversal sections (interval, 78 mum) were obtained and photographed. Reconstructions of SN were made strictly perpendicular to its long axis in the midgluteal, subgluteal, midfemoral, and popliteal regions. The epineurial area and all neural fascicles were delineated and measured. The nonneural tissue compartment inside and outside SN was also delineated and measured. The amount of neural tissue inside the epineurium decreased significantly toward distal (midfemoral/popliteal region) (P < 0.001). The relative percentage of neural tissue decreased from midgluteal (67 +/- 7%), to subgluteal (57 +/- 9%), to midfemoral (46 +/- 10%), to popliteal (46 +/- 11%). Outside the SN, the adipose compartment increased significantly toward distal (P < 0.007). In SN, the ratio neural:nonneural tissue changes significantly from 2:1 (midgluteal and subgluteal) to 1:1 (midfemoral and popliteal). This suggests a higher vulnerability for neurologic sequelae in proximal SN, and may explain differences observed in minimum effective anesthetic volume and onset time between proximal and distal SN blocks.
    Anesthesiology 10/2009; 111(5):1128-34. DOI:10.1097/ALN.0b013e3181bbc72a · 6.17 Impact Factor