Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China,
Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Respiration. 2022;101(3):291-298. doi: 10.1159/000519279. Epub 2021 Oct 27.
Transbronchial cryobiopsy (TBCB), a novel way of obtaining a specimen of lung tissue using a flexible cryoprobe, can obtain large lung biopsies without crush artifacts. The freezing time of TBCB was empirically selected from 3 to 7 s in the previous studies. However, no consensus has yet been reached regarding the optimal freezing time used in TBCB.
The primary endpoint was biopsy size in different freezing times. The secondary endpoints included sample histological quality, diagnostic confidence, and complications in different freezing times.
Patients who were suspected of DPLD requiring histopathological examination for further evaluation were enrolled in this study. Distinct biopsies were obtained by using different freezing times increased from 3 to 6 s sequentially. Samples were reviewed by 2 external expert pathologists.
A total of 33 patients were enrolled, and 143 transbronchial cryobiopsies were taken in this trial. An average of 4.33 samples were taken from each patient. The mean biopsy size of different freezing times from 3 to 6 s was 9.10 ± 4.37, 13.23 ± 5.83, 16.26 ± 5.67, and 18.83 ± 7.50 mm2, respectively. A strong correlation between freezing time and biopsy size was observed (r = 0.99, p < 0.01). Statistically significant difference of biopsy size was detected in the freezing time of 3 s versus 4 s (p < 0.01) and 4 s versus 5 s (p = 0.02), but not in the freezing time of 5 s versus 6 s (p = 0.10). Overall bleeding in different freezing times from 3 to 6 s was 53.33%, 67.50%, 89.47%, and 77.14%, respectively. A significantly higher overall bleeding was observed when the freezing time exceeded 4 s (RR = 1.67, p < 0.01). Pneumothorax occurred in 4 cases (12.12%). One lethal case (3.03%) was noted 25 days after TBCB. Lung parenchyma was preserved well in all cryobiopsy samples. Thirty-one (93.94%) patients' histopathological findings were identified as sufficient to establish a CRP diagnosis. There was no statistical difference in diagnostic confidence between different freezing times.
A longer freezing time was associated with a larger size of the biopsy sample but a higher risk of bleeding. The optimal transbronchial cryobiopsy freezing time is 3-4 s, which is easily achievable and provides an adequate biopsy size whilst creating a safety threshold from complications.
经支气管冷冻活检（TBCB）是一种使用柔性冷冻探针获取肺组织标本的新方法，可获得无挤压伪影的大肺活检标本。在之前的研究中，TBCB 的冷冻时间经验性地选择为 3 至 7 秒。然而，目前尚未就 TBCB 中使用的最佳冷冻时间达成共识。
主要终点是不同冷冻时间的活检大小。次要终点包括不同冷冻时间的样本组织学质量、诊断信心和并发症。
本研究纳入了疑似 DPLD 需要进行组织病理学检查以进一步评估的患者。通过顺序增加 3 至 6 秒的不同冷冻时间来获取不同的活检标本。由 2 位外部专家病理学家对标本进行评估。
本研究共纳入 33 例患者，共进行了 143 次经支气管冷冻活检。每位患者平均获取 4.33 个样本。3 至 6 秒不同冷冻时间的活检大小分别为 9.10±4.37、13.23±5.83、16.26±5.67 和 18.83±7.50mm²。冷冻时间与活检大小之间存在很强的相关性（r=0.99，p<0.01）。在 3 秒与 4 秒（p<0.01）和 4 秒与 5 秒（p=0.02）的冷冻时间之间，活检大小存在统计学显著差异，但在 5 秒与 6 秒的冷冻时间之间（p=0.10）则没有差异。3 至 6 秒不同冷冻时间的总体出血率分别为 53.33%、67.50%、89.47%和 77.14%。当冷冻时间超过 4 秒时，总体出血明显增加（RR=1.67，p<0.01）。4 例（12.12%）发生气胸。1 例（3.03%）患者在 TBCB 后 25 天发生致命性病例。所有冷冻活检标本中肺实质均保存良好。31 例（93.94%）患者的组织病理学发现足以建立 CRP 诊断。不同冷冻时间之间的诊断信心没有统计学差异。
较长的冷冻时间与活检标本的较大尺寸相关，但出血风险更高。最佳的经支气管冷冻活检冷冻时间为 3-4 秒，容易实现，提供了足够的活检尺寸，同时创造了一个安全的并发症阈值。
