Background:Transbronchial lung cryobiopsy (TBLC) has been used to establish the diagnosis of interstitial lung disease (ILD) in recent years. The technique and diagnostic yield vary among institutions. We report a new 2-scope technique and the results of TBLC in our institution.Methods:This is a retrospective chart review of patients who underwent TBLC for evaluation of ILD. Bronchoscopy with TBLC was performed by a board-certified interventional pulmonologist with a 2-scope technique under general anesthesia.Results:A total of 74 patients underwent TBLC with a 2-scope technique. Their mean age was 54±14 years. The mean tissue surface area was 63.54±6.76 mm2. The average anesthesia time was 80.66 minutes. The diagnostic yield was 87.84%. The most common diagnosis was sarcoidosis pneumothorax, which occurred in 5 cases (7%). There was 1 case with bronchoscopic-related respiratory failure associated with significant bleeding. Death occurred in 3 cases (4%), which is comparable to recent mortality data for “elective” surgical lung biopsy for ILD (1.7% to 4.2%).Conclusion:TBLC with a 2-scope technique could be an alternative method for diagnosing various types of ILD in patients unfit for surgical lung biopsy. Further prospective studies should clarify its role in the diagnostic armamentarium for undiagnosed ILDs.

Background: Percutaneous transcatheter pulmonary valve replacement (TPVR) has good clinical and hemodynamic outcomes in treating dysfunctional bioprosthetic valves (BPV) in the pulmonary position. Valve-in-valve therapy can further decrease the inner diameter (ID), potentially resulting in patient-prosthesis mismatch in patients with smaller BPVs. Methods and Results: To evaluate feasibility and outcomes of intentional BPV fracture to enlarge the pulmonary valve orifice with TPVR, 37 patients from 13 centers who underwent TPVR with intended BPV fracture were evaluated. A control cohort (n=70) who underwent valve-in-valve TPVR without attempted fracture was evaluated. BPV was successfully fractured in 28 patients and stretched in 5 while fracture was unsuccessful in 4. A Melody valve was implanted in 25 patients with fractured/stretched frame and a Sapien (XT 3) valve in 8. Among patients whose BPV was fractured/stretched, the final ID was a median of 2 mm larger (0–6.5 mm) than the valve’s true ID. The narrowest diameter after TPVR in controls was a median of 2 mm smaller ( P <0.001) than true ID. Right ventricular outflow tract gradient decreased from median 40 to 8 mm Hg in the fracture group. Cases with fracture/stretching were matched 1:1 (weight, true ID) to controls. Post-TPVR peak gradient was lower but not significant (8.3±5.2 versus 11.8±9.2 mm Hg; P =0.070). There were no fracture-related adverse events. Conclusions: Preliminary experience shows intentional fracture of BPV frame can be useful for achieving larger ID and better hemodynamics after valve-in-valve TPVR.

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Accuracy of chest high-resolution computed tomography in diagnosing diffuse cystic lung diseasesTo the Editor:The diffuse cystic lung diseases (DCLDs) are a group of pathophysiologically heterogeneous processes characterised by the presence of multiple, thin-walled, air-filled spaces within the pulmonary parenchyma [1]. The differential diagnosis of DCLDs includes lymphangioleiomyomatosis (LAM), follicular bronchiolitis (FB), lymphocytic interstitial pneumonia (LIP), Birt-Hogg-Dubé syndrome (BHD), pulmonary Langerhans cell histiocytosis (PLCH), amyloidosis, light chain deposition disease, cystic metastases, infectious entities such as Pneumocystis, and other aetiologies [2]. Bronchiectasis and bullous changes seen in chronic obstructive pulmonary disease can also produce high-resolution computed tomography (HRCT) patterns that mimic the DCLDs.The utility of HRCT in the diagnosis of LAM and differentiation from other DCLDs is not completely defined. According to the European Respiratory Society (ERS) guidelines, characteristic HRCT features along with a compatible clinical history are sufficient to confidently diagnose LAM, without the need for a tissue biopsy [3]. However, previously reported accuracy rates for diagnosing LAM based on HRCT findings may not be sufficient in an era when interventions with substantial risks are becoming available. Two prior studies have reported accuracy rates of 72-84% in diagnosing LAM based on imaging characteristics alone [4,5]. The aim of our study was to determine the diagnostic accuracy of HRCT evaluation by radiologists and pulmonologists, at various levels of expertise, in patients with DCLDs presenting to referral centres.We retrospectively obtained HRCTs from 89 patients referred to LAM Foundation Clinics at the University of Cincinnati (Cincinnati, OH, USA), Mayo Clinic Rochester ( Rochester, MN, USA) and National Kinki-Chou Hospital (Osaka, Japan) for further evaluation of DCLDs. All scans were non-contrast HRCTs and only thin section (1-3 mm) images were employed in the analysis. Patient 1196 identifiers were removed and the digital image files and a DICOM viewer (Santesoft, Athens, Greece), with full scrolling and magnification capabilities, were distributed to all reviewers. When necessary, abdominal cuts of the HRCT were removed to ensure that pathognomonic abdominal features, such as the presence of angiomyolipomas, would not influence the interpretation. The scans were analysed by three expert thoracic radiologists, and 12 pulmonary physicians with varying levels of expertise, subclassified as DCLD expert pulmonologists (n=5), general pulmonologists (n=4) and pulmonary fellows (n=3).Observers were asked to record the most likely diagnosis and degree of confidence (confident or not confident). Observers were blind to all clinical or pathological data. Images used for analysis were exclusively derived from patients with definite diagnoses established by biopsy, genetic testing or professional society guidelines. The results were used to calculate sensitivity and sp...