Abstract
A new method of endoscopic ultrasound (EUS) guided fine needle aspiration using an
ultrasonic endoscope with a curved array transducer mounted in front of the optic
lens was developed. As a result of the sector shaped sound field and the direction
of the scanning plane it was possible to visualise ultrasonically a needle inserted
through the biopsy channel. EUS guided biopsy was performed in 37 patients (with 39
lesions) using three types of needles. Based upon initial testing of several prototype
needles a 160 cm long, 0.8 mm diameter needle placed in a Teflon catheter was developed
after preliminary results with the first two types were unsatisfactory (positive results
for malignancy in 3/11 and 4/8 cases). The third prototype was tested in seven patients
with malignant tumours of the upper GI tract. In these patients EUS guided biopsy
was positive for malignancy in 7 of 8 solid lesions. Problems related to the technique
and criteria for a successful outcome are discussed. The preliminary results show
that it is possible to advance a needle into a malignant lesion inside or outside
the GI wall during EUS examination and aspirate material for cytologic examination
from various lesions. Controlled studies are needed to determine the indications for
use and the accuracy of the technique.
