Assessment of efficacy and safety of endoscopic lung volume reduction with one-way valves in patients with a very low FEV1.

Introduction: Endoscopic lung volume reduction (ELVR) with one-way valves produces beneficial outcomes in patients with severe emphysema. Evidence on the efficacy remains unclear in patients with a very low forced expiratory volume in 1 s (FEV1) (≤20% predicted). We aim to compare clinical outcomes of ELVR, in relation to the FEV1 restriction. Methods: All data originated from the German Lung Emphysema Registry (Lungenemphysem Register), which is a prospective multicentric observational study for patients with severe emphysema after lung volume reduction. Two groups were formed at baseline: FEV1 ≤20% pred and FEV1 21-45% pred. Pulmonary function tests (FEV1, residual volume, partial pressure of carbon dioxide), training capacity (6-min walk distance (6MWD)), quality of life (modified Medical Research Council dyspnoea scale (mMRC), COPD Assessment Test (CAT), St George's Respiratory Questionnaire (SGRQ)) and adverse events were assessed and compared at baseline and after 3 and 6 months. Results: 33 patients with FEV1 ≤20% pred and 265 patients with FEV1 21-45% pred were analysed. After ELVR, an increase in FEV1 was observed in both groups (both p<0.001). The mMRC and CAT scores, and 6MWD improved in both groups (all p<0.05). The SGRQ score improved significantly in the FEV1 21-45% pred group, and by trend in the FEV1 ≤20% pred group. Pneumothorax was the most frequent complication within the first 90 days in both groups (FEV1 ≤20% pred: 7.7% versus FEV1 21-45% pred: 22.1%; p=0.624). No deaths occurred in the FEV1 ≤20% pred group up to 6 months. Conclusion: Our study highlights the potential efficacy of one-way valves, even in patients with very low FEV1, as these patients experienced significant improvements in FEV1, 6MWD and quality of life. No death was reported, suggesting a good safety profile, even in these high-risk patients.

Diffuse Alveolar Hemorrhage Associated with Epithelioid Angiosarcoma of the Lung: A Challenging Diagnosis.

A 68-year-old patient presented with persistent hemoptysis and weight loss. A CT scan showing diffuse bilateral ground-glass opacities and nodules was followed by bronchoscopy. While diffuse alveolar hemorrhage (DAH) could be seen, specimens obtained during bronchoscopy did not provide conclusive histological findings. The decision was made to conduct video-assisted wedge resection, after which histological examinations revealed the diagnosis of bifocal nodular manifestation of an epithelioid angiosarcoma in the lung. Being a rare entity even among sarcomas, these kinds of tumors can be primary lung tissue angiosarcomas or metastatic lesions with primaries in places like the skin, breast, and heart. Treatment usually includes chemotherapy, but prognosis remains grim. This case highlights that in DAH, uncommon causes should be considered, and sufficient probe gathering is the key to early diagnosis and treatment.

Endoscopic Lung Volume Reduction with One-Way Valves in Patients with Severe Chronic Obstructive Pulmonary Disease with Hypercapnia.

BACKGROUND: Robust clinical evidence on the efficacy and safety of endoscopic lung volume reduction (ELVR) with one-way valves in patients with severe lung emphysema with chronic hypercapnic respiratory failure is lacking. OBJECTIVE: The aim of this study was to compare patient characteristics, clinical outcome measures, and incidences of adverse events between patients with severe COPD undergoing ELVR with one-way valves and with either a partial pressure of carbon dioxide (pCO2) of ≤45 mm Hg or with pCO2 >45 mm Hg. METHODS: This was a multicentre prospective study of patients with severe lung disease who were evaluated based on lung function, exercise capacity (6-min walk test [6-MWT]), and quality-of-life tests. RESULTS: Patients with pCO2 ≤45 mm Hg (n = 157) and pCO2 >45 mm Hg (n = 40) showed similar baseline characteristics. Patients with pCO2 ≤45 mm Hg demonstrated a significant increase in forced expiratory volume in 1 s (p < 0.001), a significant decrease in residual volume (RV) (p < 0.001), and significant improvements in the quality of life and 6-MWT at the 3-month follow-up. Patients with pCO2 >45 mm Hg had significant improvements in RV only (p < 0.05). There was a significant decrease in pCO2 between baseline and follow-up in hypercapnic patients, relative to the decrease in patients with pCO2 ≤45 mm Hg (p = 0.008). Patients who were more hypercapnic at baseline showed a greater reduction in pCO2 after valve placement (r = -0.38, p < 0.001). Pneumothorax was the most common adverse event in both groups. CONCLUSIONS: ELVR with one-way valves seems clinically beneficial with a remarkably good safety profile for patients with chronic hypercapnic respiratory failure.

Endoscopic lung volume reduction with endobronchial valves in very low D LCO patients: results from the German Registry - Lungenemphysemregister e.V.

BACKGROUND: Endoscopic lung volume reduction (ELVR) with valves has been suggested to be the key strategy for patients with severe emphysema and concomitant low diffusing capacity of the lung for carbon monoxide (D LCO). However, robust evidence is still missing. We therefore aim to compare clinical outcomes in relation to D LCO for patients treated with ELVR. METHODS: We assessed D LCO at baseline and 3 months follow-up and compared pre- and postprocedural pulmonary function test, quality of life, exercise capacity and adverse events. This is a retrospective subanalysis of prospectively collected data from the German Lung Emphysema Registry. RESULTS: In total, 121 patients treated with ELVR were analysed. Thirty-four patients with a D LCO ≤20% and 87 patients with a D LCO >20% showed similar baseline characteristics. After ELVR, there was a decrease of residual volume (both p<0.001 to baseline) in both groups, and both demonstrated better quality of life (p<0.01 to baseline). Forced expiratory volume in 1 s (FEV1) improved significantly only in patients with a D LCO >20% (p<0.001 to baseline). Exercise capacity remained almost unchanged in both groups (p=0.3). The most frequent complication for both groups was a pneumothorax (D LCO ≤20%: 17.6% versus D LCO >20%: 16.1%; p=0.728). However, there were no significant differences in other adverse events between both groups. CONCLUSIONS: ELVR improves lung function as well as quality of life in patients with D LCO >20% and D LCO ≤20%. Adverse events did not differ between groups. Therefore, ELVR should be considered as a treatment option, even in patients with a very low D LCO.

Improving the Mechanical Strength of Dental Applications and Lattice Structures SLM Processed.

To manufacture custom medical parts or scaffolds with reduced defects and high mechanical characteristics, new research on optimizing the selective laser melting (SLM) parameters are needed. In this work, a biocompatible powder, 316L stainless steel, is characterized to understand the particle size, distribution, shape and flowability. Examination revealed that the 316L particles are smooth, nearly spherical, their mean diameter is 39.09 µm and just 10% of them hold a diameter less than 21.18 µm. SLM parameters under consideration include laser power up to 200 W, 250-1500 mm/s scanning speed, 80 µm hatch spacing, 35 µm layer thickness and a preheated platform. The effect of these on processability is evaluated. More than 100 samples are SLM-manufactured with different process parameters. The tensile results show that is possible to raise the ultimate tensile strength up to 840 MPa, adapting the SLM parameters for a stable processability, avoiding the technological defects caused by residual stress. Correlating with other recent studies on SLM technology, the tensile strength is 20% improved. To validate the SLM parameters and conditions established, complex bioengineering applications such as dental bridges and macro-porous grafts are SLM-processed, demonstrating the potential to manufacture medical products with increased mechanical resistance made of 316L.

Heat stress is associated with reduced health status in pulmonary arterial hypertension: a prospective study cohort.

BACKGROUND: Summer heat waves with temperature extremes are becoming more frequent with growing numbers in morbidity and mortality in patients with respiratory diseases. The aim of this study was to evaluate the ramifications of heat stress (temperature >25 °C) on the health status of patients with pulmonary arterial hypertension (PAH). METHODS: Fifteen patients with PAH (mean age = 66.7 ± 5.2 years) continuously wore an accelerometer from April 1 to September 30, 2011, and their daily step count was recorded. In addition, patients kept a diary to record data on seven standardized questions regarding their daily symptoms. Echocardiography, 6-minute walk test, NTproBNP, and Modified Medical Research Council Scale (MMRC) were assessed at baseline and at the end of the study after 6 months. RESULTS: On heat-stress days, patients showed significantly more symptoms and lower total steps/day compared to thermal comfort days (3,995 ± 2,013 steps/day vs. 5,567 ± 2,434 steps/day, respectively; P < 0.001). There was a significant negative correlation between total steps/day and Temp(max) (R = -0.47; P < 0.001) and humidity (R = -0.34; P < 0.001). A significant positive correlation was found between daily symptoms and Temp(max) (R = +0.79; P < 0.001) and humidity (R = +0.23; P < 0.001). CONCLUSIONS: Heat stress is associated with a compromised clinical status in patients with PAH. Adaptation strategies must be implemented to prevent heart-related morbidity, including therapeutic adjustments and adequate room cooling in the patient's home and at the hospital.

Development of a low cost high precision three-layer 3D artificial compound eye.

Artificial compound eyes are typically designed on planar substrates due to the limits of current imaging devices and available manufacturing processes. In this study, a high precision, low cost, three-layer 3D artificial compound eye consisting of a 3D microlens array, a freeform lens array, and a field lens array was constructed to mimic an apposition compound eye on a curved substrate. The freeform microlens array was manufactured on a curved substrate to alter incident light beams and steer their respective images onto a flat image plane. The optical design was performed using ZEMAX. The optical simulation shows that the artificial compound eye can form multiple images with aberrations below 11 µm; adequate for many imaging applications. Both the freeform lens array and the field lens array were manufactured using microinjection molding process to reduce cost. Aluminum mold inserts were diamond machined by the slow tool servo method. The performance of the compound eye was tested using a home-built optical setup. The images captured demonstrate that the proposed structures can successfully steer images from a curved surface onto a planar photoreceptor. Experimental results show that the compound eye in this research has a field of view of 87°. In addition, images formed by multiple channels were found to be evenly distributed on the flat photoreceptor. Additionally, overlapping views of the adjacent channels allow higher resolution images to be re-constructed from multiple 3D images taken simultaneously.

Freeform manufacturing of a microoptical lens array on a steep curved substrate by use of a voice coil fast tool servo.

We report what is to our knowledge the first approach to diamond turn microoptical lens array on a steep curved substrate by use of a voice coil fast tool servo. In recent years ultraprecision machining has been employed to manufacture accurate optical components with 3D structure for beam shaping, imaging and nonimaging applications. As a result, geometries that are difficult or impossible to manufacture using lithographic techniques might be fabricated using small diamond tools with well defined cutting edges. These 3D structures show no rotational symmetry, but rather high frequency asymmetric features thus can be treated as freeform geometries. To transfer the 3D surface data with the high frequency freeform features into a numerical control code for machining, the commonly piecewise differentiable surfaces are represented as a cloud of individual points. Based on this numeric data, the tool radius correction is calculated to account for the cutting-edge geometry. Discontinuities of the cutting tool locations due to abrupt slope changes on the substrate surface are bridged using cubic spline interpolation.When superimposed with the trajectory of the rotationally symmetric substrate the complete microoptical geometry in 3D space is established. Details of the fabrication process and performance evaluation are described.

Poor dopaminergic response of impaired dexterity in Parkinson's disease: Bradykinesia or limb kinetic apraxia?

Patients with Parkinson's disease (PD) often show impaired manual dexterity even when being only minimally bradykinetic, suggesting that they may have limb kinetic apraxia (LKA), that is, a loss of fine motor skill not explained by elemental motor deficits. To explore this dissociation, we investigated the differential dopaminergic responsiveness of dexterity and bradykinesia in PD. Twelve patients with PD (4 women, age 64.4 +/- 8.3, mean + SD) and 12 matched healthy controls (64.8 +/- 8.9) were tested twice in ON vs. OFF and 1st vs. 2nd trial, respectively. A coin rotation (CR) task was applied to assess dexterity and a finger tapping (FT) task to assess bradykinesia. Performance was followed by video recording and analyzed by measuring the frequency of CR and FT during three 10-second periods. Statistical analysis was done by a mixed factorial design with group (PD vs. controls) as between-subject factor and medication (ON- vs. OFF-state or 1st vs. 2nd trial), task (FT vs. CR), and handedness (dominant vs. nondominant) as within-subject factors. In patients with PD, regardless of hand involved, dopaminergic treatment only mildly improved CR performance, in contrast to the strong increase in FT scores (up to the level of controls), as demonstrated by the significant triple interaction of the factors group, medication, and task (F(1,22) = 7.9, P = 0.01; eta(2) = 0.26). Furthermore, CR scores were considerably lower, both in OFF and ON, than in normal controls, pointing to a substantial impairment of dexterity in PD (P < 0.001). In conclusion, impaired manual dexterity showing significantly diminished response to dopaminergic treatment suggests that dextrous deficits in PD are related to LKA rather than bradykinesia.