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The Rotex Screw Needle Biopsy Instrument ®
Some advantages
The Rotex Screw Needle Biopsy Instrument offers a safe,
simple way of obtaining highly reliable samples. Since material is excised instead of
being aspirated, complete cell clusters are obtained rather than single cells. As a
result, at least 95% diagnostic accuracy has been obtained using the Rotex Screw Needle
Biopsy Instrument for sampling lung tumors (2) and non palpable breast tumors (9). The
diameter of the instrument cannula is 0.8 or 1.0 mm, which explains the low incidence of
reported complications (2)
- The instrument is easy to operate. It occupies a minimum of
space under an image intensifier.
- The instrument holder allows the examiner to keep his hand
out of the X-ray beam.
- Sampling is performed efficiently over a distance of 16 mm,
corresponding to the spiral portion of the screw needle. This enhances the possibility of
obtaining representative samples. The screw needle and cannula work together as a cutting
instrument, and the screw needle stabilize the tissue when the cannula is rotated over it.
In this way all tissue components are sampled before they are lifted out. Material from
fibrous inflammatory lesions and highly organized tissue such as benign tumors can
therefore also be obtained. The material is highly concentrated and is not diluted by
tissue fluid and blood as in aspiration biopsy. This facilitates microscopic examination
of the material. Rather large flakes of cells and connective tissue can often be obtained.
The clumps of tissue which can be sampled from organized tissue may allow treatment of the
material with histological techniques.
- Material from the screw needle can be inoculated directly
on culture media for bacteriological examination.
- The dimensions of the instrument have been optimized with
regard to minimizing trauma and maximizing stability. This latter factor is of importance
in order to enable precision sampling. In this way unnecessary insertion of the cannula in
several directions can be avoided.
- The screw needle is always in a protected position; i.e.,
withdrawn into the cannula, when the helical hub is positioned distally in the instrument
holder. In this way the risk of tumor seeding to surrounding tissue is reduced to a
minimum.
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