NEW YORK (Reuters Health) – The diagnostic yield of endobronchial biopsy is improved when specimens are obtained using a cryoprobe rather than conventional forceps, a German team reports.

“Importantly, there was no difference in the incidence of significant bleeding,” the authors comment in the European Respiratory Journal online August 18.

Dr. Juergen Hetzel, at the University of Tuebingen, and colleagues explain that forceps sampling provides relatively small amounts of tissue and crushing artefacts can affect histologic analysis, whereas the flexible cryoprobe obtains much larger samples of high quality.

As described in the report, the cryobiopsy technique involves placing the cryoprobe in suspicious lesions and initiating the freeze cycle so that the tissue attaches to the probe’s tip. While still frozen, the sample is extracted by withdrawing the entire bronchoscope since the material cannot be retracted through the instrument channel – one of the disadvantages of the technique, the authors note.

For their study, the researchers prospectively randomized 593 patients with suspected endobronchial tumors to undergo conventional endobronchial sampling or cryobiopsy. The diagnostic yield of each technique was calculated as the number of diagnostic procedures divided by number of non-diagnostic procedures plus number of diagnostic procedures.

Malignant disease was ultimately diagnosed in 563 of the patients. In this group, the diagnostic yield was 95.0% for cryobiopsy and 85.1% for standard forceps (p<0.001), the report indicates.

There was no difference in the time needed for biopsy and subsequent bleeding control between the groups, at 5.05 versus 5.25 minutes for cryobiopsy and forceps biopsy, respectively, the investigators report, and the number of bleeding complications needing any intervention did not differ between the groups.

“In conclusion,” Dr. Hetzel and colleagues write, “endobronchial cryobiopsy is a safe technique with a higher diagnostic yield for the diagnosis of endobronchial malignancies than forceps biopsy and might extend the chest physician’s armamentarium of obtaining sufficient endobronchial tissue for a definitive diagnosis.”

Reference:
Cryobiopsy increases the diagnostic yield of endobronchial biopsy: a multicentre trial
Eur Resp J 2011.