Feasibility of Using the O-Arm Imaging System During ENB-rEBUS-guided Peripheral Lung Biopsy: A Dual-center Experience.

BACKGROUND: There is a paucity of real-time imaging modalities available for the bronchoscopic biopsy of peripheral lung nodules. We aim to demonstrate the feasibility of the O-arm imaging system to guide real-time biopsies of peripheral lung nodules during electromagnetic navigation bronchoscopy. METHODS: A retrospective review was performed at 2 academic medical centers utilizing O-arm guidance. RESULTS: The average nodule size was 2.1×2.0 cm and were mostly solid (66%) with a positive bronchus sign (83%). O-arm imaging confirmed tool-in-lesion in all cases. The diagnostic yield was 33%. Four cases were nondiagnostic of the 6 cases performed. In these cases, necrotic tissue was the most common (75%) and showed resolution following subsequent imaging. The average 3-dimensional (3D) spin time was 23.5 seconds. The average number of 3D spins performed per case was 4.33. The average effective dose per 3D spin was 3.73 mSv. CONCLUSION: We have demonstrated the O-arm's feasibility with electromagnetic navigation bronchoscopy for peripheral lung nodules. The O-arm was able to confirm tool-in-lesion in all cases which added confidence to the biopsy. Four high-resolution 3D spins per case may limit the total computed tomography effective dose. We also noted that both metal and radiation scatter were minimal when appropriate radiation safety standards were met. Although additional experience and data will be required to verify the O-arm approach for routine use, our initial experience is promising.

Diffuse alveolar hemorrhage is most often fatal and is affected by graft source, conditioning regimen toxicity, and engraftment kinetics.

Diffuse alveolar hemorrhage after hematopoietic stem cell transplantation is a frequently fatal complication with no standard therapy. Although significant changes in supportive and intensive care measures for patients undergoing hematopoietic stem cell transplantation have been made over the past decades, the impact of these changes on the incidence and outcome of patients with diffuse alveolar hemorrhage has not been examined. We analyzed 1228 patients who underwent allogeneic hematopoietic stem cell transplantation between 2008-2015 at the University of Minnesota to study the incidence, risk factors, and outcomes of diffuse alveolar hemorrhage. Diffuse alveolar hemorrhage developed in 5% of allogeneic hematopoietic stem cell transplant recipients, at a median of 30 days (range +3 to +168 days) after transplantation. The incidence of diffuse alveolar hemorrhage was significantly greater in recipients of umbilical cord blood than peripheral blood or bone marrow grafts (HR: 2.08, 95% CI: 1.16-3.74; P=0.01). In multivariate analysis, delayed neutrophil engraftment or primary graft failure was a risk factor for diffuse alveolar hemorrhage following peripheral blood or bone marrow hematopoietic stem cell transplants (HR: 5.51, 95% CI: 1.26-24; P=0.02) and delayed platelet engraftment was associated with significantly increased diffuse alveolar hemorrhage in umbilical cord blood transplant recipients (HR: 6.96, 95% CI: 2.39-20.29; P<0.05). Myeloablative regimens including total body irradiation were also risk factors for diffuse alveolar hemorrhage (HR: 1.8, 95% CI: 1.03-3.13, P=0.05) in both peripheral blood or bone marrow and umbilical cord blood hematopoietic stem cell transplants (HR: 1.87, 95% CI: 0.95-3.71). Patients with diffuse alveolar hemorrhage had an inferior 6-month treatment-related mortality (HR: 6.09, 95% CI: 4.33-8.56, P<0.01) and 2-year overall survival (HR: 4.16, 95% CI: 3.06-5.64; P<0.01) using either graft source. The etiology of diffuse alveolar hemorrhage is multifactorial, involving lung injury influenced by high-dose total body irradiation, graft source, and delayed engraftment or graft failure. The survival of patients with diffuse alveolar hemorrhage after hematopoietic stem cell transplantation remains poor. Clinical interventions or experimental studies (e.g., cell expansion for umbilical cord blood transplants or thrombopoietin use) that modulate these risk factors may limit the incidence and improve the outcomes of diffuse alveolar hemorrhage.

Myeloid sarcoma: an unusual presentation for acute tracheal stenosis.

BACKGROUND AND AIMS: Extramedullary involvement of acute myelogenous leukemia (AML) is rare and has been reported under the terms myeloid sarcoma (MS), granulocytic sarcoma, chloroma, extramedullary acute myeloid leukemia, myeloblastoma and myelosarcoma. The most common extramedullary involvement includes soft tissues and lymph nodes, but it may arise in different sites of the body. There are only very few reports about MS in the pulmonary system, and involvement of the trachea is extremely rare. METHODS: This is the first report of initial presentation of MS by severe acute tracheal stenosis. RESULTS: After failed tracheal dilatation, a tracheostomy was performed where tracheal tissue was submitted for pathology. Histology of the tracheal biopsy and bone marrow revealed AML. The patient was subsequently referred to our oncology service for further management. CONCLUSION: Myeloid sarcoma should be part of the differential for acute tracheal stenosis.