Comparing the 1.1 mm cryoprobe versus flexible forceps for lung transplant acute allograft rejection diagnosis

Transbronchial lung biopsy in lung transplant recipients has traditionally been performed via forceps (FBx) but is associated with poor-quality specimens and crush artifacts. The novel 1.1 mm cryoprobe (CBx) with oversheath could obtain a larger sample with better hemostatic control. We hence performed a study comparing FBx and CBx for surveillance biopsy in lung transplant recipients.

We conducted a prospective, observational single-center study of adult lung transplant recipients who underwent transbronchial biopsies during surveillance. The samples were obtained with standard transbronchial forceps and 1.1 mm cryoprobe through flexible bronchoscopy for each patient in the same procedure. Outcomes of FBx and CBx were compared and analyzed.

We performed FBx and CBx in 49 patients with a mean age of 62 years, 51 % were male, and 82 % underwent bilateral lung transplant. The CBx yielded a significantly higher area of alveolated tissue compared to FBx (19.3 vs 5.4 mm², p < 0.001). The diagnostic rate was higher with CBx compared to FBx with respect to acute rejection (100 % vs 96 %), airway inflammation (53 % vs 38 %) and chronic rejection (45 % vs 39 %) though none achieved statistical significance. No major bleeding or pneumothorax were noted in our study.

CBx with the 1.1 mm probe could provide a higher rate of detecting lung allograft dysfunction with an excellent safety profile. Similar studies with larger sample sizes are needed to prove statistical significance.