Nerve detection with optical spectroscopy for regional anesthesia procedures.

Contains fulltext : 152523.pdf (publisher's version ) (Open Access

Real-time in vivo assessment of radiofrequency ablation of human colorectal liver metastases using diffuse reflectance spectroscopy

Background The success of radiofrequency (RF) ablation is limited by the inability to assess thermal tissue damage achieved during or immediately after the procedure. The goal of this proof-of-principle study was to investigate whether diffuse reflectance (DR) spectroscopy during and after RF ablation of liver tumours could aid in detecting complete tissue ablation. Material and methods DR spectra were acquired in vivo in eight patients undergoing RF ablation for unresectable colorectal liver metastases, using a disposable spectroscopy needle. Intraoperative ultrasound imaging was used for accurate positioning of the RF electrode and the spectroscopy needle. Spectral changes were quantified and correlated to tissue histopathology and follow-up CT imaging. Results For the lesions in which ablation was monitored by DR spectroscopy (N = 8), median tumour size was 1.6 cm (range 0.8–3.3 cm). We found an excellent correlation (97–99%) between thermal damage suggested by spectral changes and histology. DR spectroscopy allowed discrimination between non-ablated and ablated tissue, regardless whether the needle was placed in tumour tissue or in surrounding liver tissue. Additional measurements performed continuously during ablation confirmed that the magnitude of spectral change correlates with the histochemical degree of thermal damage. Conclusions Diffuse reflectance spectroscopy allows accurate quantification of thermal tissue damage during and after RF ablation. Real-time feedback by DR spectroscopy could improve the accuracy and quality of the RF procedures by lowering incomplete ablation rates

Near-infrared fluorescence (NIRF) imaging in breast-conserving surgery: Assessing intraoperative techniques in tissue-simulating breast phantoms.

Breast-conserving surgery (BCS) results in tumour-positive surgical margins in up to 40% of the patients. Therefore, new imaging techniques are needed that support the surgeon with real-time feedback on tumour location and margin status. In this study, the potential of near-infrared fluorescence (NIRF) imaging in BCS for pre- and intraoperative tumour localization, margin status assessment and detection of residual disease was assessed in tissue-simulating breast phantoms.Breast-shaped phantoms were produced with optical properties that closely match those of normal breast tissue. Fluorescent tumour-like inclusions containing indocyanine green (ICG) were positioned at predefined locations in the phantoms to allow for simulation of (i) preoperative tumour localization, (ii) real-time NIRF-guided tumour resection, and (iii) intraoperative margin assessment. Optical imaging was performed using a custom-made clinical prototype NIRF intraoperative camera.Tumour-like inclusions in breast phantoms could be detected up to a depth of 21 mm using a NIRF intraoperative camera system. Real-time NIRF-guided resection of tumour-like inclusions proved feasible. Moreover, intraoperative NIRF imaging reliably detected residual disease in case of inadequate resection.We evaluated the potential of NIRF imaging applications for BCS. The clinical setting was simulated by exploiting tissue-like breast phantoms with fluorescent tumour-like agarose inclusions. From this evaluation, we conclude that intraoperative NIRF imaging is feasible and may improve BCS by providing the surgeon with imaging information on tumour location, margin status, and presence of residual disease in real-time. Clinical studies are needed to further validate these results

Infant feeding patterns are associated with cardiovascular structures and function in childhood

Nutrition in infancy seems to be associated with cardiovascular disease and its risk factors in adulthood. These associations may be explained by cardiovascular developmental adaptations in childhood in response to specific infant feeding patterns. The aim of this study was to assess whether duration and exclusivity of breastfeeding and timing of introduction of solid foods affect cardiovascular development in childhood. In a population-based prospective cohort study from fetal life onward, information about duration and exclusivity of breastfeeding and timing of introduction of solid foods was obtained from delivery reports and questionnaires. Blood pressure, carotid-femoral pulse wave velocity (PWV), left atrial diameter (LAD), aortic root diameter (AOD), left ventricular (LV) mass, and fractional shortening (FS) were measured at a median age of 6.0 y (95% range: 5.6-7.4 y). Analyses were based on 5003 children. Age at introduction of solid foods was negatively associated with systolic and diastolic blood pressure at the age of 6 y. Compared with children who had ever been breast-fed, never-breast-fed children had a higher carotid-femoral PWV (β: 0.13 m/s; 95% CI: 0.03, 0.24 m/s), a smaller LAD (β: 20.29 mm; 95% CI:20.55,20.03 mm), and less LV mass (b:21.46 g; 95% CI:22.41,20.52 g) at the age of 6 y. Among breast-fed children, duration and exclusivity were not associated with cardiovascular structures or function. Breastfeeding pattern and age at introduction of solid foods were not associated with AOD or FS. Feeding patterns in infancy may influence cardiovascular development in childhood. Further research is required to replicate these findings and to investigate whether these changes contribute to an increased risk of cardiovascular disease in later life

Desempenho, eficiência de utilização dos nutrientes e estrutura do trato digestório de pintos de corte alimentados na fase pré-inicial com rações de diferentes formas físicas Performance, efficiency of nutrient utilization and gastrointestinal structures of broiler chick fed in prestarter phase with ratios with different physical form

Este estudo foi realizado com o objetivo de avaliar o efeito da forma física da ração sobre o desempenho, a utilização dos nutrientes das rações e o desenvolvimento do trato disgestório de pintos de corte na primeira semana de vida. Foram utilizados 150 pintos machos Cobb distribuídos ao acaso em três tratamentos com cinco repetições de dez aves. Os tratamentos consistiram das formas físicas farelada, triturada e peletizada de uma ração pré-inicial comercial. Com exceção da moela, os órgãos do trato digestório e a estrutura morfométrica do intestino não foram influenciados pela forma física da ração. Maior digestibilidade do N foi obtida com a ração peletizada, enquanto a ração triturada possibilitou maior digestibilidade do EE. A energia metabolizável determinada para a ração farelada foi menor que a obtida nas demais formas físicas da ração. As aves alimentadas com raç��o farelada tiveram menor consumo de ração e ganho de peso e pior conversão alimentar. Ingeriram ainda menos energia, apresentaram menores retenções de proteína, gordura e energia corporal e utilizaram maior proporção da energia ingerida para produção de calor. As rações pré-iniciais na forma peletizada ou triturada possibilitam maior aproveitamento dos nutrientes da ração pelos pintos e melhor desempenho.<br>This experiment was conducted to evaluate the effect of different physical form of pre-starter diet on performance, nutrient utilization and development of gastrointestinal tract of broiler chicks during the first week of age. A total of 150-day-old male broiler chicks was allotted to a completely randomized design with three treatments and five replicates of 10 birds each. Treatments consisted of three physical forms of a commercial pre-starter diet: mashed, crumbled and pressed into pellets. Except for gizzard, the other organs of the digestive tract and morphologic structures of the small intestine were not affected by the physical form of the diet. The highest N digestibility was observed in birds fed pellet diet, while crumbled diet showed the highest digestibility of EE. The metabolizable energy determined for mashed diet was lower than those determined for the other physical forms of the diet. Birds fed mashed diet had the lowest feed intake and body weight gain and the worse feed conversion. These birds also showed lower intake of energy and less protein, fat and energy retention in the body. They used a higher proportion of the energy consumed for heat production. Pre-starter diets prepared as pellets or crumbles allow better nutrient utilization and improve chick performance