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U.C.H SKELETAL MUSCLE BIOPSY NEEDLE






Sizes:

8G x 3 1/8"   CAT#7502-713M
7G x 4 3/4"   CAT#7502-713L
6G x 4 3/4"   CAT#7502-713N
4G x 4 3/4"   CAT#7502-713T

Developed by the staff at University College Hospital Medical School and Muscle Research Centre Hammersmith Hospital. Needle is offered with an aspirating facility for use during the biopsy procedure - thus providing larger specimens than previously available. Needle biopsy has the advantage over open biopsy in it being, essentially, an outpatient procedure.

NEEDLE BIOPSY OF MUSCLE IN CLINICAL PRACTICE

R.H.T. Edwards, C.A. Maunder, J.M. Round, C.M. Wiles, A Young
University College Hospital Medical School and Jerry Lewis Muscle Research Centre, Hammersmith Hospital.

The needle biopsy technique is a simple, harmless, rapid and repeatable means of sampling human muscle for pathological diagnosis1,2. We have used it successfully in over 400 patients of all ages (including children). Muscles which have been sampled include quadriceps femoris, gastrocnemius, tibialis anterior, deltoideus, pectorelis, biceps brachialis, triceps and erector spinae.

Needle biopsy does not disfigure by leaving an unsightly scar. Patients are usually willing to have repeated biopsies. Morphological comparison (by both light and electron microscopy) of repeated biopsies taken over a period of several months gives a vivid impression of the time course of muscle repair. Our experience shows that needle biopsy is economically preferable to open biopsy since it is essentially an out patient procedure. It also yields diagnostically valuable results in clinical situations where the electromyogram is normal and open biopsy might not be considered ethical.

1. R.H.T. Edwards, C.A. Maunder, P.D. Lewis, A.G.E. Pearse (1973) Lancaet ii, 1070–1071.
2. R.H.T. Edwards, C.A. Maunder (1977) Hospital Update 3, 569-581

NEEDLE SIZE, SAMPLE SIZE

Generally, specimens around 20-40mg containing approximately 100-700 muscle fibres are obtainable via needle biopsy.

The following Needle specifications are offered as a guide:
8G, I.D.=0.135" (=3.5 mm)
7G, I.D.=0.15" (=3.8 mm)
6G, I.D.=0.172" (=4.35 mm)
4G, I.D.=0.21" (=5.3 mm)
Please note that the above dimensions refer to I.D. of the outer needle. An inner needle is inserted coaxially into the outer needle and acts to "guillotine" the muscle at the hatch or window of the outer needle. Conservatively, subtract about 0.8 mm from the above figures to arrive at I.D. of inner needle.

PROCEDURE

Performed under local anesthetic and sterile conditions.

• Local anesthetic ( 1% lignocaine) is infiltrated into the skin and subcutaneous tissues as far as the fascia but not into the muscle itself.
• Incise skin and deep fascia 3 to 5mm with Paragon blade No. 11.
• Remove from needle its obdurator.
• Insert needle with window closed – i.e. inner needle is advanced to its furthest forward position.
• Advance needle, moving easily through skin until resistance is felt from the muscle sheath. Push needle into muscle sheath.
• Guillotine a sample of tissue by opening outer needle window (retract inner needle) and then closing window with forward thrust of inner needle.
• Remove needle, using obdurator to evacuate specimen.
• Close wound, seal skin.

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