Transbronchial Biopsy and Needle As...

Transbronchial Biopsy and Needle Aspiration

Fiberoptic bronchoscopy has greatly expanded the diagnostic capability of bronchoscopy through that provided by the rigid bronchoscope greatly of this expansion has been related to the ability to use transbronchial sampling with greater precision and safety. For many years now, transbronchial forceps biopsy, first pioneered as a technique for rigid bronchoscopy [1] and as a radiologic technique, has been a standard diagnostic deed More recently, a number of aspiration needle have become available for use by the agency of the fiberoptic bronchoscope, which have further expanded the diagnostic range of bronchoscopy providing enhanced access to peripheral as well as to submucosal and mediastinal lesions.

Although diagnosis of cancer is perhaps the greatest in number common application of these techniques, they can be applied to a wide range of pathologic processe In many situations, bronchoscopy with transbronchial biopsy can play an important part in the diagnosis of infections. Application to noninfectious benign disease is also possible, although it may be more limited from the experience of the cytopathologist.

This review guards the instrumentation needed for transbronchial sampling, the techniques applyed in transbronchial biopsy and transbronchial needle aspiration, and the applications of these conducts Their limitations and possible corrections of these limitations are also explored.

EQUIPMENT

Forceps

Bronchoscopic forceps have changed alone slightly since their introduction almost 20 years ago. They are hinged lots with either a cutting intensity or a serrated edge (alligator forceps). greatest in number plain cup forceps today have a window in each bowl to limit crushing the specimen, although it has not at any time been demonstrated that this modification is effective in limiting crush artifact. While these forceps have a cutting opening [i]or[/i] close in practice tissue is frequently torn rather than cleanly cross in the course of transbronchial biopsy. This tearing action does not appear to have any clinically deleterious effect

Alligator forces are chiefly useful for grasping foreign bodies, further they can also be used for transbronchial biopsy. A possible, still unproved, disadvantage of alligator forceps for transbronchial biopsy is their lack of a cutting animation The entire action is a tearing united In the past, the bowls of alligator forceps were significantly larger than those of plain forceps, on the other hand the diagnostic yield was not higher using them despite the increase in specimen size. In fact, while the pair cup and alligator forceps arrive in two sizes to fit large- and small-channel bronchoscope the diagnostic yield is similar (unpublished data). Accuracy in sampling the lesion and the number of samples taken appear to be more important than the actual sample size. As a arise plain cup forceps of either size are appropriate instruments for transbronchial biopsy.

Needles

A number of bronchoscopic aspirating needle are now available in sizes ranging from 18 to 23 gauge. The basic design of most numerous needles is similar, consisting of a metal needle attached to a catheter that is housed in an exterior sheath into which the needle and its catheter can be withdrawn. more [i]or[/i] less devices have obturators whose major function is to provide stiffening for the catheter. An obturator is probably not necessary for needle occlusion to obviate sampling of intervening tissue, as it is for transthoracic aspiration, since the needle generally passes solely through the relatively thin bronchial or tracheal wall. A not many needles that are not retractable use a blunt-tipped obturator protruding from the needle to obstruct the needle from damaging the bronchoscope channel. Nevertheless, these nonretractable devices probably still bewilder some risk of channel damage.

Needle also vary in caliber and continuance For sampling peripheral masses and hilar and subcrinal nodes, a amplification of 1 cm is useful. Shorter needle (05 cm) can be used to sample submucosal tissue, on the other hand the 1-cm length is also appropriate for this application. Longer needle at least 13 cm are best for transtracheal aspiration because of the oblique angle ofttimes involved in this technique. Longer needle (greater than 1 cm) are not practical, however, for peripheral applications, because the longer rigid distal section limits maneuverability of the device from one side the bronchial branches.

For chiefly applications, the gauge should be at least 20 to 21 Thinner needle many times provide insufficient specimens. Eighteen- or 19-gauge needle have newly become available and appear to be useful in adding cores of tissue to the aspiration specimen. [2] The ability to combine histologic with cytologic examination usually increases the diagnostic yield. Despite the larger size, these needle do not appear to increase the risk of the procedure

individual unique needle made entirely of plastic appears to be particularly useful for peripheral applications. It consists of an exterior sheath and an inner catheter with a sharpened, beveled tip. The inner catheter can be withdrawn into the sheath during passage in consequence of the bronchoscope. The advantage of this needle lies in its lack of the rigid section that is characteristic of the two forceps and needles. As a originate these needles can often be passed along sharper bends than metal needle or forceps. This possessions can be particularly useful in sampling upper lobe apical portion and lower lobe superior portion lesions, although it is useful in other areas as well. An additional advantage of this needle is its 18-gauge caliber, which oftentimes allows for obtaining histologic specimens in addition to cytologic commons Its disadvantage is that it is not optimally radiopaque in its general version. As a accrue it can sometimes be difficult to diocese fluoroscopically.