Diagnostic outcomes of robotic-assisted bronchoscopy for pulmonary lesions in a real-world multicenter community setting.

BACKGROUND: Robot-assisted bronchoscopy (RAB) is among the newest bronchoscopic technologies, allowing improved visualization and access for small and hard-to-reach nodules. RAB studies have primarily been conducted at academic centers, limiting the generalizability of results to the broader real-world setting, while variability in diagnostic yield definitions has impaired the validity of cross-study comparisons. The objective of this study was to determine the diagnostic yield and sensitivity for malignancy of RAB in patients with pulmonary lesions in a community setting and explore the impact of different definitions on diagnostic yield estimates. METHODS: Data were collected retrospectively from medical records of patients ≥ 21 years who underwent bronchoscopy with the Monarch® Platform (Auris Health, Inc., Redwood City, CA) for biopsy of pulmonary lesions at three US community hospitals between January 2019 and March 2020. Diagnostic yield was calculated at the index RAB and using 12-month follow-up data. At index, all malignant and benign (specific and non-specific) diagnoses were considered diagnostic. After 12 months, benign non-specific cases were considered diagnostic only when follow-up data corroborated the benign result. An alternative definition at index classified benign non-specific results as non-diagnostic, while an alternative 12-month definition categorized index non-diagnostic cases as diagnostic if no malignancy was diagnosed during follow-up. RESULTS: The study included 264 patients. Median lesion size was 19.3 mm, 58.9% were peripherally located, and 30.1% had a bronchus sign. Samples were obtained via Monarch in 99.6% of patients. Pathology led to a malignant diagnosis in 115 patients (43.6%), a benign diagnosis in 110 (41.7%), and 39 (14.8%) non-diagnostic cases. Index diagnostic yield was 85.2% (95% CI: [80.9%, 89.5%]) and the 12-month diagnostic yield was 79.4% (95% CI: [74.4%, 84.3%]). Alternative definitions resulted in diagnostic yield estimates of 58.7% (95% CI: [52.8%, 64.7%]) at index and 89.0% (95% CI: [85.1%, 92.8%]) at 12 months. Sensitivity for malignancy was 79.3% (95% CI: [72.7%, 85.9%]) and cancer prevalence was 58.0% after 12 months. CONCLUSIONS: RAB demonstrated a high diagnostic yield in the largest study to date, despite representing a real-world community population with a relatively low prevalence of cancer. Alternative definitions had a considerable impact on diagnostic yield estimates.

Activity and stability of the catalytic hydrogel membrane reactor for treating oxidized contaminants.

The catalytic hydrogel membrane reactor (CHMR) is an interfacial membrane process that uses nano-sized catalysts for the hydrogenation of oxidized contaminants in drinking water. In this study, the CHMR was operated as a continuous-flow reactor using nitrite (NO2-) as a model contaminant and palladium (Pd) as a model catalyst. Using the overall bulk reaction rate for NO2- reduction as a metric for catalytic activity, we evaluated the effect of the hydrogen gas (H2) delivery method to the CHMR, the initial H2 and NO2- concentrations, Pd density in the hydrogel, and the presence of Pd-deactivating species. The chemical stability of the catalytic hydrogel was evaluated in the presence of aqueous cations (H+, Na+, Ca2+) and a mixture of ions in a hard groundwater. Delivering H2 to the CHMR lumens using a vented operation mode, where the reactor is sealed and the lumens are periodically flushed to the atmosphere, allowed for a combination of a high H2 consumption efficiency and catalytic activity. The overall reaction rate of NO2- was dependent on relative concentrations of H2 and NO2- at catalytic sites, which was governed by both the chemical reaction and mass transport rates. The intrinsic catalytic reaction rate was combined with a counter-diffusional mass transport component in a 1-D computational model to describe the CHMR. Common Pd-deactivating species [sulfite, bisulfide, natural organic matter] hindered the reaction rate, but the hydrogel afforded some protection from deactivation compared to a batch suspension. No chemical degradation of the hydrogel structure was observed for a model water (pH > 4, Na+, Ca2+) and a hard groundwater after 21 days of exposure, attesting to its stability under natural water conditions.

Catalytic Hydrogel Membrane Reactor for Treatment of Aqueous Contaminants.

Heterogeneous hydrogenation catalysis is a promising approach for treating oxidized contaminants in drinking water, but scale-up has been limited by the challenge of immobilization of the catalyst while maintaining efficient mass transport and reaction kinetics. We describe a new process that addresses this issue: the catalytic hydrogel membrane (CHM) reactor. The CHM consists of a gas-permeable hollow-fiber membrane coated with an alginate-based hydrogel containing catalyst nanoparticles. The CHM benefits from counter-diffusional transport within the hydrogel, where H2 diffuses from the interior of the membrane and contaminant species (e.g., NO2-, O2) diffuse from the bulk aqueous solution. The reduction of O2 and NO2- were investigated using CHMs with varying palladium catalyst densities, and mass transport of reactive species in the catalytic hydrogel was characterized using microsensors. The thickness of the "reactive zone" within the hydrogel affected the reaction rate and byproduct selectivity, and it was dependent on catalyst density. In a continuously mixed flow reactor test using groundwater, the CHM activity was stable for a 3 day period. Outcomes of this study illustrate the potential of the CHM as a scalable process in the treatment of aqueous contaminants.

Endobronchial ablative therapies.

Endobronchial ablative therapies are used to address a variety of malignant and benign airway lesions. By utilizing endobronchial ablative techniques patients with symptomatic airway lesions may receive significant symptom improvement, improved quality of life, and improved life expectancy. Endobronchial ablative therapies include laser, electrocautery, argon plasma coagulation, cryotherapy, brachytherapy, and photodynamic therapy. The choice to use one therapy versus another depends on technical and patient specific factors. This article reviews indications and contraindications for each therapy, discusses details related to each endobronchial ablative therapy, complications of endobronchial ablative therapies, and briefly discusses practical consideration with endobronchial ablative therapies.

Tracheomalacia/Tracheobronchomalacia and hyperdynamic airway collapse.

Tracheobronchomalacia (TBM) and hyperdynamic airway collapse (HDAC) can be debilitating diseases associated with decreased functional capacity and poor quality of life, although there is no standard definition of this complex condition, and there are numerous terms used to describe it. The diverse etiology associated with TBM and HDAC can obscure and delay an accurate diagnosis for years. A thorough medical history is important in understanding possible causes and in guiding diagnostic testing. Medical history may also suggest what treatments may be most beneficial.

Tracheal paraganglioma: an unusual neoplasm of the upper airway.

Paraganglioma of the trachea is a rare neoplasm, with fewer than 15 cases reported. A 40-year-old man presented with stridor and hemoptysis. Bronchoscopy demonstrated a tumor of the posterior trachea and biopsy initially suggested typical carcinoid. The patient underwent surgical resection uneventfully and made a good recovery. Final pathology disclosed the tumor to be a paraganglioma based on immunohistology. The pathophysiology and treatment of this tumor are discussed.

Health care utilization history, GOLD guidelines, and respiratory medication prescriptions in patients with COPD.

BACKGROUND: The relationship between prior health care utilization and respiratory medication prescriptions in an unselected population of patients with COPD is not known. METHODS: We determined the prescribed respiratory medications and respiratory and nonrespiratory health care encounters in 523 Veterans with COPD at the Cincinnati Veterans Affairs Medical Center between 2000 and 2005. Prescribed treatments were compared with the GOLD guidelines and each patient was classified as receiving less medications than recommended in the guidelines (G). RESULTS: Respiratory medications were G for 14% of the patients studied. For GOLD stages 1 and 2, G patients the most prior respiratory encounters during a 12 month period (0.31 +/- 0.073 (0.21, 0.47), 0.75 +/- 0.5 (0.37, 1.5), 1.1 +/- 0.27 (0.74, 1.6) visits/person/year, G, respectively, mean + standard error of mean (SEM) (95% confidence limits) 2 degrees of freedom (df) ANOVA P < 0.001 for prescription effect). For GOLD stages 3 and 4, G respectively, 2 df ANOVA P = 0.096) or for GOLD stages 3 and 4 (3.6 +/- 0.25 (3.2, 4.1) and 4.0 +/- 0.44 (3.3, 4.9) visits/person/year,

The mean green popsicle: using cryotherapy to remove aspirated foreign bodies.

Foreign body (FB) aspiration can be a life-threatening event. Although more common in children, FB aspiration can occur at any age. Symptoms related to FB aspiration range from coughing and shortness of breath to asphyxiation. Chest imaging can be nonspecific and infrequently identifies an FB. Herein, we describe a case of a 54-year-old male patient who aspirated an FB and experienced respiratory arrest. He failed to improve with conservative measures and required emergent bronchoscopy. He was found to have an FB in his proximal left mainstem bronchus that could not be removed using standard bronchoscopy and he was referred to our center for definitive care. We used a cryotherapy probe to remove the FB. We propose that cryotherapy is a useful tool to remove FBs that are soft and amenable to freezing.