RESUMEN
Endosonography is an established method for staging gastrointestinal malignancies. As an extension of imaging, several case series have described employing endosonography in conjunction with needle aspiration biopsy to sample lesions within and adjacent to the gastrointestinal tract. This added ability to perform endosonography guided fine needle aspiration biopsy may overcome some of the specificity problems associated with EUS in distinguishing benign from malignant lesions (e.g. lymph nodes, pancreatic masses, and gastric ulcers). To date, a large prospective evaluation has not been reported describing the accuracy of EUS-FNA or the safety of the technique. From November, 1991 till September, 2002: 1544 patients (904 males, 640 female) of average age (67,2 years extreme 17-88 years) had one or several EUS-FNA. Biopsies are performed at the end of ultrasound endoscopy examinations, the patient lying down on their left side. Neuroleptanaesthaesia is generally necessary. The biopsy technique is quite simple, and takes place in the following sequence: a) the lesion is positioned on the needle's exit path, b) the stylet is withdrawn, then the needle is inserted into the tumour. The operator can visualise the tip of the needle by ultraound enabling its correct position in the lesion to be verified, c) aspiration is performed with the aid of a 20 ml syringe as the needle makes to-and-fro movements within the tumour. One to three passages are usually necessary in order to obtain a micro-biopsy. As regards the 1544 patients having had an EUS-FNA, the result of the biopsy was confirmed either by surgical investigation or coelioscopy, or by the evolution and the follow-up of the patients. A complication occurred in 15 patien's (0,97 percent) it was about 9 feverish episodes, about 5 acute pancreatitis and of 1 bleeding. As regards result, for the diagnosis of malignancy, sensibility, specificity, predictive positive value, predictive negative value and the accuracy of EUS-FNA were respectively 84,6 percent-98,4 percent-99,6 percent-54,7 percent and 86,9 percent fot the 1544 patients. For the solid tumors of the pancreas, concerning the diagnosis of malignancy, sensibility, specificity, accuracy of EUS-FNA were respectively 89,8 percent and 90,1 percent