| BackgroundTransbronchial cryobiopsy(TBCB)is a new way of lung biopsy.In previous studies,compared to traditional transbronchial lung biopsy(TBLB),TBCB has better diagnostic rate for interstitial lung disease(ILD),lung transplantation rejection monitoring,peripheral pulmonary lesions and lung malignancies.TBCB provides larger but less damaged specimens with good safety profile.As there are more and more studies about TBCB and its application is becoming more and more widely,the optimum technique is being investigated,such as the impact of different cryoprobe freezing time on specimen size and quality.Objective:This study was intended to evaluate the correlation between freezing time and the size of specimens,the effects of different freezing time on the quality of tissue specimens and the incidence of complications and the differences of effects of different freezing time on biopsy tissue cells,providing advises for the clinical application of TBCB.Methods:TBCB was performed on 3 adult beagle dogs under general anesthesia with tracheal intubation.According to different freezing time 3-8 seconds,6-10 specimens were obtained for each freezing time.The correlation between size of specimen and freezing time were evaluated.The incidence of complications(pneumothorax and hemorrhage)was recorded and the relation between freezing time and complication was evaluated.The histopathological quality of specimens were evaluated by observing whether the specimens contained terminal bronchioles,arterioles,and alveolar tissue.The effects of different freezing time on the tissue cells of specimens were evaluated by observing the presence of cell swelling,cell deformation,cell contraction,and nuclear pyknosis in specimens.Results:A total of 44 biopsies were taken with cryoprobe in this experiment,14,17 and 13 biopsies were performed in each Beagle dog.The average cross-sectional area of cryobiopsies ranged from(12.2±2.2)mm2 to(32.9±4.0)mm2.There was significant difference in the size of specimen between different freezing time(F=2.569,p=0.043).The size of specimen was positively correlated with freezing time(r=0.850,p<0.001).The majority of transbronchial cryobiopsies were associated with grade 0-1 haemorrhage(75%,33/44).There was no grade 3 haemorrhage beyong endoscopic control,causing hemodynamic instability and respiratory dysfunction and even sacrifice of the animal.However,grade 2 haemorrhage(25%,11/44)occurred in 3 seconds,5 seconds,6 seconds,7 seconds,and 8 seconds of freezing time.Pneumothorax appeared once in each of the freezing time of 5 seconds,6 seconds,and 8 seconds.All specimens contained pulmonary parenchyma,and most of the tissues were structurally intact.Small arteries were observed in 97.7%(43/44)of the specimens.Terminal bronchioles were observed in 97.7%(43/44)of the specimens.Alveolar tissue can be observed in 100%(44/44)of the specimens.Specimens of good histopathological quality can be obtained when the freezing time is longer than 4 s.When the freezing time is 4 s,the complication rate is relatively low.No crush artifact was observed in the specimens.All specimens showed no cell swelling.Cell morphological changes,cell shrinkage and nuclear pyknosis were observed in a very small number of cells.There were no significant differences in cell swelling,cell deformation,cell contraction,and nuclear pyknosis of specimens between different freezing times.Conclusion:The size of the transbronchial cryobiopsies was positively correlated with the freezing time.The longer the freezing time,the larger the specimen.Specimens of good histopathological quality can be obtained with a freezing time of 3-8 seconds.Different freezing times has no significant effect on the cell morphology of the specimen.When the freezing time is 4s,the quality of the obtained specimen is good,and the complications are relatively small.It can be used as the initial freezing time for transbronchial cryobiopsy. |
PDF Full Text Request