Transbronchial cryobiopsy in diffuse lung disease

Transbronchial Cryobiopsy in Interstitial Lung Disease: Are We on the Right Path?

BACKGROUND

A definitive and specific diagnosis of interstitial lung disease (ILD) often requires a histologic analysis of the lung parenchyma. A transbronchial biopsy with forceps has a limited diagnostic yield for idiopathic interstitial pneumonias. The incorporation of a transbronchial lung cryobiopsy for diagnosing ILD appears to be very promising, although there are only a few published studies in this regard. Our paper shows the results of using this technique in our center.

METHODS

This was a prospective study including 55 patients with ILD diagnosed from January 2012 to January 2015. The methodology used, the overall diagnostic yield, and the number and the location of samples, in addition to complications, have been reported.

RESULTS

In 38 (69%), 10 (20.8%), and 7 (12.7%) cases, we obtained a certain, highly likely, and unclassifiable diagnosis of interstitial pneumonia, respectively. With 18 cases, usual interstitial pneumonia was the most common diagnosis. The most common complication was a pneumothorax in 8 patients (14.5%).

CONCLUSIONS

A transbronchial lung cryobiopsy using a flexible cryoprobe has a good diagnostic yield and might be an alternative to consider in cases of diffuse ILD in which a histologic sample is required for diagnosis. This technique could avoid a large number of surgical biopsies.

Evaluation of Transbronchial Lung Cryobiopsy Size and Freezing Time: A Prognostic Animal Study

BACKGROUND

Transbronchial lung biopsy using a cryoprobe is a novel way of sampling lung parenchyma. Correlation of freezing time with biopsy size and complications has not been evaluated in vivo.

OBJECTIVES

The primary aim of the study is to evaluate the correlation between transbronchial cryobiopsy freezing time and size. The secondary aims are to evaluate histological quality of the biopsy and evaluate procedure-associated complications.

METHODS

Transbronchial lung cryobiopsies were obtained from two anaesthetised sheep using a 1.9-mm cryoprobe inserted into a flexible bronchoscope under fluoroscopic guidance. Freezing times ranged from 1 to 6 s (n = 49). The cryobiopsies were evaluated histologically with respect to their size and quality. Complications of bleeding and pneumothorax were recorded.

RESULTS

The mean cross-sectional area of the cryobiopsy ranged from 4.7 ± 2.1 to 15.7 ± 15.3 mm2. There was a significant positive correlation between increasing freezing time and cryobiopsy cross-sectional area (p = 0.028). All biopsies contained lung tissue with preserved parenchyma. Crush and freeze artefacts were not observed and tissue architecture was intact in all specimens. Small blood vessels and terminal bronchioles were observed in 88% of specimens. All cryobiopsies caused nil or mild haemorrhage with the exception of only 1 episode of severe haemorrhage at 6 s freezing time. Pneumothoraces occurred at 2, 5 and 6 s freezing time and required chest tube insertion. The most significant haemorrhage and pneumothoraces occurred at 5 and 6 s. Our results suggest an initial freezing time of 3 s can provide the maximal biopsy size while minimising major complications.

CONCLUSION

The optimal transbronchial cryobiopsy freezing time is initially 3 s. This time is associated with minimal complications and large artefact-free biopsies.

Usefulness of an angioplasty balloon as selective bronchial blockade device after transbronchial cryobiopsy

BACKGROUND AND OBJECTIVE

Transbronchial cryobiopsy (TBCB) is a technique in which frozen samples of lung are obtained using a probe inserted through a bronchoscope. We performed a retrospective study to assess the performance of the TBCB procedure complemented by segmental bronchial blockade using an angioplasty balloon, in terms of diagnostic yield and safety in diffuse parenchymal lung disease (DPLD).

METHODS

Data from 100 patients with suspected DPLD (clinical and radiological findings), who underwent TBCB in our institution to establish a definitive diagnosis, were reviewed. In our institution, TBCB is monitored with fluoroscopy and performed under general anaesthesia by a multidisciplinary team (an anaesthesiologist, a pulmonologist and an interventional radiologist). In each patient, four samples were collected using a 2.4-mm distal diameter cryoprobe. To control bleeding, the biopsied segmental bronchus was blocked with a 6-mm diameter angioplasty balloon, inserted over a 0.035-inch angled hydrophilic guidewire. After the cryoextraction, the balloon was inflated for 3 min intervals until bleeding stopped.

RESULTS

Overall, 98% of samples had diagnostic value. In 85% of cases, DPLD was confirmed, while in 7%, cancer was diagnosed. Complications were observed in 16% of the patients: 13 patients developed moderate haemorrhage, and 3 developed pneumothorax.

CONCLUSION

Transbronchial cryobiopsy had a high diagnostic yield for DPLD. Performing the procedure under fluoroscopy guidance and using angioplasty balloon for selective bronchial blockade achieved a low rate of iatrogenic complications directly associated with the technique.