Optimization of Transbronchial Cryobiopsy in Lung Transplant Recipients

Previous studies suggest that transbronchial lung biopsy using a cryoprobe is superior to transbronchial lung biopsy using forceps for evaluating lung grafts, although the technique can be associated an increase in complications. Because cryoprobe experience is limited, assessment of a greater number of cases is warranted. This prospective study evaluates the diagnostic yield, complications, and risk factors associated with the cryoprobe technique.

From April 2013 to April 2016, 321 consecutive cryoprobe transbronchial biopsies were indicated in single or bilateral lung transplant patients with acute or chronic clinical lung injury or in asymptomatic patients before hospital discharge after lung transplantation.

With a mean of 4.32 lung parenchyma specimens per procedure, adequate alveolar lung parenchyma was obtained in 96.6% (84.27 ± 44.14 mm²) of cases. Obtaining at least 4 samples increased the histological diagnostic certainty (P < .001). Moderate to severe bleeding was observed in 7.48% of patients and was significantly more frequent in patients with unilateral transplantation (odds ratio, 0.10; 95% confidence interval, 0.02-0.30; P < .001) and in those with high blood pressure during scanning (odds ratio, 0.31; 95% confidence interval, 0.12-0.86; P = .019). Pneumothorax was observed in 7.7% of the patients, but only 3.7% of these patients required pleural drainage.

Obtaining 4 or more cryobiopsy samples is valuable and safe for lung allograft monitoring. Being a recipient of a unilateral lung transplant or having arterial hypertension during bronchoscopy seem to be risk factors associated with increased bleeding.