High Efficiency of Cryobiopsy in Diagnosing Benign Endobronchial Lesions Tõnu Vanakesa1,2, Sirje Marran1, Ingemar Almre1, Ruth Sepper3, and Alan Altraja4 1Departments of Endoscopy and 2Cardiothoracic Surgery, North Estonia Medical Centre Foundation, Tallinn, Estonia, 3Institute of Clinical Medicine, Tallinn University of Technology, Tallinn, Estonia, and 4Department of Pulmonary Medicine, University of Tartu, Estonia Background and Rationale Cryobiopsies have been proven efficient in making the final morphological diagnosis of central lung cancer. However, no published data exist on the value of cryobiopsies in diagnosing the benign lesions of the central lower airways. Aims To evaluate the power of cryobiopsy technique in confirming the morphology of benign lesions of the central lower airways in relation to the forceps biopsies, both obtained under fiberoptic bronchoscopy. Materials and Methods To reveal retrospectively, whether the cryobiopsy technique was superior to the forceps biopsies in terms of the diagnostic yield, cases with a benign diagnosis were randomly selected out of those with endoscopic signs of endobronchial lesions. The patients were referred to the Department of Endoscopy of the North Estonia Medical Centre and the Bronchoscopy Unit of the Lung Clinic of the Tartu University Hospital, Estonia and had undergone both cryobiopsy and ordinary forceps biopsy to make the final diagnosis of their endobronchial process. An Erbokryo CA cryosystem (ERBE Elektromedizin GmbH, Tübingen, Germany), which operates using the Joule-Thomson effect, was used for obtaining cryobiopsies during fiberoptic videobronchoscopy under local anesthesia. A cryoprobe of 2.4 mm in diameter was applied. The indepndence of the cryobiopsy results on other variables was confirmed using Mantel-Haenszel test Results A total of 31 patients (21 males, 10 females, median age 64.0 yr, range 17–81 yr) were evaluated. Cryobiopsies were obtained from all 31 patients and a clinically reasonable non-malignant diagnosis (Table 1) was confirmed all cases as well (Table 2). The median number of cryobiopsies taken per patient was 1 (Table 2). Instead, forceps biopsies were taken in 14 cases, the median number of biopsies per patient was 2.5, but the diagnosis was confirmed in 12 cases (85.4%). The cryobiopsy appeared to be superior to the forceps biopsy in terms of providing the final morphology of the lesion (p=0.031) (Table 2). Although the number of cryobiopsies per patient was significantly lower than that of forceps biopsies (p<0.001), the median size of cryobiopsies was larger than that of forceps biopsies (p<0.001). Table 1. The final non-malignant diagnoses obtained using cryobiopsy technique from the 31 patients studied from Estonia. Table 2. Comparison between cryobiopsies and forceps biopsies from the randomly selected 31 patients from Estonia with non-malignant final diagnoses. The morphological diagnosis from the cryobiopsy was not dependent on the following demographic and clinical characteristićs of the patients: Age (p=0.48) Gender (p=0.13) Number of cryobiopsies taken (p=0.92) Biopsy size (p=0.72) Location of the process in the lower airways (p=0.28) (Table 3) Final diagnosis itself (p=0.33) (Figure 1) Table 3. Location of the benign process diagnosed with cryobiopsy technique among the 31 patients studied from Estonia. Diagnosis Frequency (No.) Frequency (%) Benign inflammatory infiltration 8 25.8 Foreign body 4 12.9 Benign non-sarcoid granuloma 3 9.7 Benign metaplasia 2 6.5 Bronchial tuberculosis Chronic bronchitis Acute bronchitis 1 3.2 Bronchial fibrosis Lipoma Mucosal hyperplasia Myofibroblastic neoplasm Organized blood clot Endobronchial hamartoma Polyp Sarcoidosis Wegener's granulomatosis Location Frequency (No.) Frequency (%) RC 7 22,6 RLL 5 16,1 RUL LUL 4 12,9 RML 3 9,7 Trachea LC 2 6,5 LLL R=right L=left C=central UL=upper lobe ML=middle lobe LL=lower lobe A B Right middle lobe bronchus Conclusions Analogously to that, what we formerly confirmed for malignant diseases, cryobopsy is an efficient tool in making the diagnosis of the benign endobronchial lesions. Cryobiopsy could thus be recommended as a standard procedure during fiberoptic videobronchoscopy because providing better morphology (larger biopsies without squeeze artifacts). Cryobiopsies N=31 (100.0%) Forceps biopsies N=14 (45.2%) p-value Final morphology obtained, proportion (%) 31/31 (100.0%) 12/14 (85.4%) 0.031* Number of biopsies, median (range) 1 (1-3) 2.5 (1-4) <0.001** Size of biopsies (mm), median (range) 1.0 (0.4-15) 0.4 (0.2-0.6) Figure 1. Endobronchial hamartoma of the right middle lobe bronchus in a 54-year male patient. The diagnosis was established by cryobiopsy, but not with a series of forceps biopsies (A). Endobronchial pulyp in the right basalbronchus (B). *Pearson’s Chi square test; **Mann-Whitney rank sum test.