Feasibility and safety of parietal pleural cryobiopsy during semi-rigid thoracoscopy

Performing pleural biopsies during semi-rigid thoracoscopy is sometimes a difficult and time-consuming task because of the lack of mechanical power of dedicated flexible forceps in patients with thickened pleura. The purpose of this first ever pilot study was to test the feasibility of taking biopsy specimens by cryoprobe from the parietal pleura during semi-rigid thoracoscopy. Our aim was also to assess the diagnostic value and quality of specimens obtained, morphological features, feasibility of immunohistochemistry staining and possibility of DNA isolation. The secondary aim was to evaluate safety, tolerability and duration of the procedure.

Fifteen patients with pleural effusion of unknown origin that underwent semi-rigid thoracoscopy were included. Biopsies were obtained using a flexible autoclavable cryoprobe 20416-032 (Erbokryo CA, ERBE, Tübingen, Germany) 2.4 mm in diameter and a semi-rigid autoclavable Olympus LTF-160 (Olympus, Tokyo, Japan) thoracoscope.

Tissue samples were obtained from 14 patients (93.3%), three from each. Of the samples, 81% were easily interpretable and 19% were interpretable with some difficulty by the pathologist. The samples were of good quality, with the level of artifacts below 25%. The specimens were adequate for histological diagnosis, immunohistochemical staining and DNA isolation. There were no moderate or major bleeding problems after the biopsies; two patients experienced pain. The median duration of three cryobiopsies (per patient) was 4 min (range 3-6 min).

Cryobiopsy during semi-rigid thoracoscopy appears worth to be evaluated in a larger prospective multicenter trial as our preliminary data were promising for efficacy and safety.