title: The cryo-needle: a new tool for histological biopsies. A feasibility study.
abstract: OBJECTIVE
  Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a standard procedure for intrathoracic lymph node biopsies. The newly developed cryo-needle operates in a similar way to the EBUS-TBNA but is able to obtain specimens for histological evaluation. The purpose of this animal study was to evaluate the feasibility, effect, and safety of the cryo-needle biopsies.
  
  
  METHODS
  Four EBUS-guided cryo-needle biopsies were obtained from a mediastinal lymph node of a healthy pig. In an open surgery approach, cryo-needle biopsies using activation times of 1, 2, and 3 s (A1/A2/A3) and needle biopsies using a 21-gauge EBUS-TBNA needle were obtained from mesenteric lymph nodes. Cryo-needle biopsies A2 were performed with (A2+) and without (A2-) an oversheath. The size, weight, percentage of lymphatic tissue and artefact-free area of each cryobiopsy were evaluated. Smears were made with the TBNA-needle aspirates to determine the number of lymphocytes per high-power field (HPF). The bleeding duration was measured.
  
  
  RESULTS
  We successfully obtained EBUS-guided cryo-needle biopsies. The area and weight of the biopsies A3 and A2+ were significantly larger compared with A1 (1.7 ± 0.8 and 1.4 ± 0.3 vs. 0.9 ± 0.4 mm(2); 5.2 ± 2.4 and 3.4 ± 1.8 vs. 1.5 ± 0.7 mg). The percentage of lymphatic tissue of the cryobiopsies was 90 ± 25 and 98 % of samples were artefact-free. The number of lymphocytes/HPF of TBNA-needle smears was 128 ± 54.3. There was no difference in bleeding duration between the techniques.
  
  
  CONCLUSIONS
  The cryo-needle yields large histological specimens of high quality.
authors.affiliation: Department of Pneumology and Critical Care Medicine, Helios Klinik Ambrock, Chair of Internal Medicine I, Witten/Herdecke University, Ambrocker Weg 60, 58091, Hagen, Germany, karl-josef.franke@helios-kliniken.de.
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Franke
authors.forename: Georg
authors.initials: G
authors.lastname: Nilius
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Ruehle
authors.forename: Markus D
authors.initials: MD
authors.lastname: Enderle
authors.forename: Walter
authors.initials: W
authors.lastname: Linzenbold
authors.forename: Claus Hann
authors.initials: CH
authors.lastname: von Weyhern
mesh_terms: D000818:Animals; D016477:Artifacts; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000009:adverse effects / Q000295:instrumentation*; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005615:Freezing; D006470:Hemorrhage / Q000209:etiology; D008198:Lymph Nodes / Q000473:pathology*; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000473:pathology*; D023421:Models, Animal; D009339:Needles; D011237:Predictive Value of Tests; D013552:Swine; D013997:Time Factors