Selection of Needle
There are many types of needles available for percutaneous biopsies
of lung lesions. Each one has advantages and disadvantages. The
selection of the needle is dependent on the individual case and
Aspiration for Cytology Only
- Spinal Needle:
The spinal needle is 9 cms long and comes in sizes of 18, 20, 22
and 25. The thinner needles have the least number of
complications. However, the larger sized
needles yield more material for examination. Obviously, the spinal
needle will not be suitable
for lesions deeper than 9 cms from the chest wall. The spinal
needle does not provide tissue.
Hence, benign tumors and granulomas cannot be diagnosed. It is
ideal for cytological
confirmation of malignancy and/or for bacteriological exam of a
patient with pneumonia. I use
a size 22 spinal needle.
- Rotex Screw:
- Purpose Made:
The needle consists of two
stylets: solid and
corkscrew brush. The assembled needle is inserted into the
periphery of the lesion and the inner
stylet withdrawn. The corkscrew stylet is inserted 1/3 of the way
into the lesion and the
withdrawn sharply to trap fragments of the tumor in the interstices
of the screw thread. This
provides the first specimen. The outer shank is advanced 2/3 of
the way into the lesion and the
corkscrew withdrawn. The second specimen is now obtained.
Negative pressure is applied to
the outer shank by suction and the needle is advanced to the far
side of the tumor to obtain the
final third specimen. The advantage of this needle is that with
one puncture of the pleura and
lung, multiple specimens can be obtained.
Plus Core of Tissue
- Turner Needle:
The needles are thin walled and have a 45
degree bevel angle with
a circumferentially cutting edge. This allows for a wider lumen
then the spinal needles.
- Trucut Biopsy:
Trucut biopsy needles provide the
largest core of tissue than
any other needle. However, the risk of pneumothorax and hemoptysis
are very high with the
use of this needle.
There are case reports of exsanguinating hemoptysis following
trucut biopsy of diffuse lung
disease resulting in death. Hence, it is contraindicated for
diffuse lung disease. Transbronchial
lung biopsy can provide adequate tissue and is the choice procedure
for diffuse lung disease.
The trucut biopsy can be used safely for masses that are adjacent
to the chest wall. The bleeding
is usually minimal and is better controlled in a mass lesion. I
don't recommend this needle for
a deeper mass lesion where you have to transgress lung tissue.
- Slotted Needle:
The 20 gauge needle is modified to include
a slotted opening
measuring 2.2 mm in length, located approximately 3 mm from the tip
of the needle. The slot
creates a second cutting edge in addition to the needle tip. It
seems to enable aspiration of
larger amounts of material. In approximately 50% of biopsies,
small tissue bits are obtained.
This enables obtaining histological sections as well as cytology.
Needles of three lengths are
available: 9, 14 and 18 cms).
Selection of Needle
The selection of which needle you use, depends on the following:
- Depth to Reach from the Chest Wall:
Spinal 9 cms in length Other needles are 9,
14 and 18 cms in length
Minimal with size 25 needle. Maximum with
trucut biopsy needles.
- Diagnostic Consideration:
For a diagnosis of a benign
tumor and granuloma, use needles that can yield a core of tissue.
The aspiration is usually sufficient for cytology and