[Long-term results of the early endoscopic treatment of acquired tracheal-subglottic stenosis: 10 years of experience]. / Resultados a largo plazo del tratamiento endoscópico precoz de las estenosis subglóticas y traqueales adquiridas: 10 años de experiencia.

INTRODUCTION: Acquired stenosis of the airway is a common complication after endotracheal intubation. Endoscopic dilation has been accepted as the treatment of choice in cases detected precociously. Our goal is to know the current status of the patients treated in our hospital with endoscopic dilation in the last 10 years. MATERIAL AND METHODS: Retrospective cohort study of patients with subglottic and tracheal acquired stenosis (STAS) early treated endoscopically with balloon dilation at our center in the last 10 years. Bronchoscopy control at 2 weeks, a month, 3 and 6 months post-dilation were performed and later on depending on the symptoms. RESULTS: 32 patient were treated in the period considered. The median age was 4.5 (3-120) months. There were necessary 2.5 (1-5) dilations per patient. All cases were extubated in the operating room or in the following 24 hours. There were no complications during the procedure. Follow-up time was 6 (1-10) years. Only 1 of the 32 patients have had recurrence of stenosis 2 years after, it was secondary to reintubations due to new surgical interventions; which it was dilated successfully. CONCLUSIONS: Early endoscopic dilation in the acquired airway stenosis is a safe and effective long-term procedure. The results support the use of this technique as a treatment of choice in these patients.

INTRODUCCION: La estenosis adquirida de la vía aérea es una complicación frecuente tras la intubación endotraqueal. La dilatación endoscópica ha sido aceptada como tratamiento de elección en los casos detectados de forma precoz. Nuestro objetivo es conocer el estado actual de los pacientes tratados en nuestro centro mediante dilatación endoscópica en los últimos 10 años. MATERIAL Y METODOS: Estudio de cohorte retrospectivo de pacientes con estenosis subglóticas y traqueales adquiridas (ESTA) tratadas endoscópicamente mediante dilatación con balón en nuestro centro en los últimos 10 años. Se realizaron broncoscopias de control a las 2 semanas, al mes, a los 3 y 6 meses postdilatación y posteriormente en función de la clínica. RESULTADOS: Se trataron 32 pacientes de ESTA de reciente aparición en dicho periodo. La mediana de edad fue de 4,5 (3-120) meses. Fueron necesarias 2,5 (1-5) dilataciones por paciente. Todos los pacientes fueron extubados en quirófano o en las 24 horas siguientes al procedimiento. No hubo complicaciones durante los procedimientos ni durante el postoperatorio. El tiempo de seguimiento fue de 6 (1-10) años. Solo 1 de los 32 pacientes presentó recidiva de la estenosis 2 años después que fue secundaria a reintubaciones por nuevas intervenciones quirúrgicas; la cual se dilató nuevamente. CONCLUSIONES: La dilatación endoscópica precoz en las estenosis adquiridas de la vía aérea es un procedimiento seguro y eficaz a largo plazo. Los resultados avalan el uso de esta técnica como tratamiento de elección en estos pacientes.

Graphene flakes obtained by local electro-exfoliation of graphite with a STM tip.

Graphite surfaces can be manipulated by several methods to create graphene structures of different shapes and sizes. Scanning tunneling microscopy (STM) can be used to create these structures either through mechanical contact between the tip and the surface or through electro-exfoliation. In the latter, the mechanisms involved in the process of exfoliation at an applied voltage are not fully understood. Here, we show how a graphite surface can be locally exfoliated in a systematic manner by applying an electrostatic force with a STM tip at the edge of a terrace, forming triangular flakes several nanometers in length. We demonstrate, through experiments and simulations, how these flakes are created by a two-step process: first a voltage ramp must be applied at the edge of the terrace, and then the tip must be scanned perpendicular to the edge. Ab initio electrostatic calculations reveal that the presence of charges on the graphite surface weakens the interaction between layers allowing for exfoliation at voltages in the same range as those used experimentally. Molecular dynamics simulations show that a force applied locally on the edge of a step produces triangular flakes such as those observed under STM. Our results provide new insights into surface modification that can be extended to other layered materials.

N-cadherin expression in feline mammary tumors is associated with a reduced E-cadherin expression and the presence of regional metastasis.

The cadherin family of adhesion molecules regulates cell-cell interactions. N-cadherin is expressed by neural and fibroblast cells but not by normal epithelial cells. In human medicine, the role of N-cadherin in breast cancer remains controversial, but some studies have described the switch from E-cadherin to N-cadherin as a critical step in the malignant progression of neoplastic cells. The present study was carried out on 160 feline mammary tumors (21 adenomas and 139 carcinomas). The relationship between the immunohistochemical expression of N-cadherin in neoplastic epithelial cells and 2 established prognostic factors such as regional metastasis and tumor grade was examined. The results of the study showed a statistically significant relation between the expression of N-cadherin and the 2 prognostic factors, and also a reduced expression of E-cadherin in tumors that expressed N-cadherin.

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anaesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anaesthetic in the liquid was analyzed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anaesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anaesthetic blocks.

[Translated article] Study of femoral component malrotation as a cause of pain after total knee arthroplasty.

INTRODUCTION: The total knee arthroplasty (TKA) has been shown to be a successful and cost-benefit procedure in terms of pain improvement in patient with symptomatic knee osteoarthritis. However, almost a 20% of the patients are not satisfied with the result of the surgery. MATERIAL AND METHOD: We have carried out a transversal unicentric cases controls study with clinical cases of the own hospital, obtained by a clinical records revision. A total of 160 patients with a TKA with at least 1 year of follow-up were selected. Demographic variables, functional scales (WOMAC and VAS) and rotation of the femoral component through the analysis of the images obtained by CT scan were collected. RESULTS: The total was 133 patients that was divided in two groups. A control group and pain group. The Control group was made up of 70 patients with a mean age of 69.59 years (23 men and 47 women) and the pain group was made up of 63 patients with a mean age of 69.48 years (13 men and 50 women). We didn't find difference regarding the analysis of the rotation of the femoral component. In addition, we were not found significant differences when applying a stratification by sex. And, the analysis of the malrotation of the femoral component, previously defining limits of value rotation considered as extreme, in any of the case did not show significant differences. CONCLUSION: The results of the study confirm that malrotation of the femoral component had no influence on the presence of pain at a minimum of one year of follow-up after TKA implantation.

Naturally acquired visceral leishmaniosis in a captive Bennett's wallaby (Macropus rufogriseus rufogriseus).

A high prevalence of leishmaniosis has been reported from an increasing number of domestic and wild mammals around the world. In Australian macropods, Leishmania spp infection has been occasionally described in its cutaneous form only. The purpose of this report is to present a case of fatal visceral leishmaniosis in a captive Bennett's wallaby in Madrid, Spain, which was investigated by detailed macroscopic, histologic, and immunohistochemical examinations.

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterise the elution profile of two local anaesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anaesthetic in the liquid was analysed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anaesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anaesthetic blocks.

In vitro elution of local anesthetics from PMMA bone cement. / Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA.

BACKGROUND AND AIM: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. MATERIAL AND METHODS: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. RESULTS: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). CONCLUSIONS: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.

Study of femoral component malrotation as a cause of pain after total knee arthroplasty. / Estudio de la malrotación del componente femoral como causa de dolor tras la implantación de una artroplastia total de rodilla.

INTRODUCTION: The total knee arthroplasty (TKA) has been shown to be a successful and cost-benefit procedure in terms of pain improvement in patient with symptomatic knee osteoarthritis. However, almost a 20% of the patients are not satisfied with the result of the surgery. MATERIAL AND METHOD: We have carried out a transversal unicentric cases controls study with clinical cases of the own hospital, obtained by a clinical records revision. A total of 160 patients with a TKA with at least 1year of follow-up were selected. Demographic variables, functional scales (WOMAC and VAS) and rotation of the femoral component through the analysis of the images obtained by CT scan were collected. RESULTS: The total was 133 patients that was divided in two groups. A control group and pain group. The control group was made up of 70 patients with a mean age of 69.59years (23 men and 47 women) and the pain group was made up of 63 patients with a mean age of 69.48years (13 men and 50 women). We did not found difference regarding the analysis of the rotation of the femoral component. In addition, we were not found significant differences when applying a stratification by sex. The analysis of the malrotation of the femoral component, previously defining limits of value rotation considered as extreme, in any of the case did not show significant differences. CONCLUSION: The results of the study confirm that malrotation of the femoral component had no influence on the presence of pain at a minimum of one year of follow-up after TKA implantation.

Reduced expression of E-cadherin and ß-catenin and high expression of basal cytokeratins in feline mammary carcinomas with regional metastasis.

Feline mammary carcinomas are highly aggressive neoplasms. Several mechanisms are thought to be involved in their progression, including the loss of epithelial adhesion molecules. The present study was carried out on 21 adenomas and 139 mammary carcinomas. Of the carcinomas, 66 were not reported to have metastasized, while the remaining 73 had evidence of regional lymph node metastasis at the moment of diagnosis. The relationship was examined between the expression of the E-cadherin-ß-catenin complex and basal (CK5/6, CK14) and luminal (CK8/18) cytokeratin expression. In the medical literature, carcinomas expressing basal cytokeratins are reported as having a poor prognosis in human breast cancer. Results revealed that preservation of the expression of E-cadherin and ß-catenin is a significant feature of carcinomas without metastasis, whereas carcinomas with metastasis reveal the loss of one or both adhesion molecules. Additionally, basal cytokeratin expression was statistically associated with the presence of regional metastasis. Furthermore, the expression of E-cadherin-ß-catenin was significantly correlated with the high expression of CK18 and low expression of CK5/6.

Cyclooxygenase-2 expression is related with localization, proliferation, and overall survival in canine melanocytic neoplasms.

A direct relationship has been firmly established between cyclooxygenase-2 (COX-2) expression and malignant behavior in human melanoma. This report examines the relationship between COX-2 expression and tumor location, mitotic and proliferative indices, degree of T CD3(+) lymphocyte infiltration, overall survival, and frequency of recurrence and metastasis of 57 melanocytic tumors (25 oral and 32 cutaneous). COX-2 was highly or moderately expressed in 88% of oral neoplasms (22 of 25), whereas for their cutaneous counterparts, COX-2 expression was low or insignificant in 75% of cases (24 of 32). High and moderate COX-2 expression levels were observed in 73% of melanocytic tumors with a mitotic index ≥ 3 per 10 high-power fields (26 of 36), whereas in 81% of tumors with a mitotic index < 3 (17 of 21), expression was mild or absent. There were 41 cases with known clinical outcomes; of those showing high, moderate, and mild COX-2 expression, 83.3% (10 of 12), 37.5% (3 of 8), and 25% (2 of 8) died, respectively, whereas 100% of animals showing no COX-2 expression (13 of 13) were still alive at the last follow-up. COX-2 expression was statistically correlated with tumor location, mitotic and percentage Ki-67 proliferative indices, and overall survival, frequency of neoplastic recurrence and metastasis. Regression analysis also showed disease-specific predictive value for COX-2 expression for subjects with melanocytic neoplasms. Additionally, only high COX-2 expression showed significant differences in overall survival, in comparison with moderate, mild, or absent expression. These results suggest that high COX-2 expression may be considered a prognostic biomarker and potentially as a target for therapeutic and preventive strategies in canine melanocytic neoplasms.

Vibron-assisted spin excitation in a magnetically anisotropic molecule.

The electrical control and readout of molecular spin states are key for high-density storage. Expectations are that electrically-driven spin and vibrational excitations in a molecule should give rise to new conductance features in the presence of magnetic anisotropy, offering alternative routes to study and, ultimately, manipulate molecular magnetism. Here, we use inelastic electron tunneling spectroscopy to promote and detect the excited spin states of a prototypical molecule with magnetic anisotropy. We demonstrate the existence of a vibron-assisted spin excitation that can exceed in energy and in amplitude a simple excitation among spin states. This excitation, which can be quenched by structural changes in the magnetic molecule, is explained using first-principles calculations that include dynamical electronic correlations.

Pemphigus erythematosus and cutaneous epitheliotropic lymphoma in a Labrador Retriever dog.

BACKGROUND: Paraneoplastic pemphigus is an autoimmune blistering skin disease associated with concurrent neoplasia that is rarely observed in veterinary medicine. CASE DESCRIPTION: This case report presents a ten-year-old female Labrador Retriever dog with generalized seborrhea and alopecic, crusting and ulcerative lesions in the periocular and perioral regions, the lips and the groins. FINDINGS/TREATMENT AND OUTCOME: Hematology analysis showed a marked increase in the number of lymphocytes, while the rest of the values were normal. Skin biopsies were collected and the histological findings were consistent with pemphigus in association with an epitheliotropic lymphoma. Immunohistochemical analysis was performed. There was deposition of immunoglobulin G (IgG) in the basement membrane and in the intercellular space that corresponded with an immunostaining pattern characteristic of pemphigus erythematosus (PE). The lymphoma was positive to CD3 cells and was classified as a T-cell epitheliotropic lymphoma. CONCLUSION: To our knowledge, this is the first case of PE and cutaneous lymphoma coexisting in a dog, expanding the list of associations between immune-mediated diseases and cancer in dogs, and providing support to the eventual connection between autoimmunity and neoplasia in this species.

Characterization of precipitates size distribution: validation of low-voltage STEM.

The size distribution of second phase precipitates is frequently determined using conventional transmission electron microscopy (CTEM). However, other techniques, which present different advantages, can also be used for this purpose. In this paper, we focus on high angle annular dark field (HAADF) in TEM and scanning TEM (STEM) in scanning electron microscopy (SEM) imaging modes. The mentioned techniques will be first described, then compared to more conventional ones for the measurement of carbides size distribution in two FeCV and FeCVNb model alloys. This comparative study shows that STEM in SEM, a technique much easier to undertake compared to TEM, is perfectly adapted for size distribution measurements of second phase particles, with sizes ranging between 5 and 200 nm in these systems.

Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA / In vitro elution of local anesthetics from PMMA bone cement

Antecedentes y objetivo:Actualmente, no disponemos de un gold standard para el manejo del dolor postoperatorio tras una artroplastia total de rodilla, dado que se pueden administrar analgésicos a través de diferentes vías y ninguna de estas está exenta de riesgos. El sistema ideal de administración de analgésicos debería proporcionar dosis terapéuticas, no tóxicas, en el sitio quirúrgico, especialmente durante las primeras 72h. El cemento óseo utilizado en las artroplastias se ha usado como un medio de liberación de fármacos, especialmente antibióticos, desde 1970. Basado en este principio, se desarrolló este estudio con el objetivo de conocer el perfil de elución de dos anestésicos locales (hidrocloruro de lidocaína e hidrocloruro de bupivacaína) desde el cemento óseo de polimetilmetacrilato (PMMA). Material y métodos: Se obtuvieron especímenes de cemento óseo Palacos® R+G e hidrocloruro de lidocaína o hidrocloruro de bupivacaína según el grupo de estudio. Estos especímenes se sumergieron en PBS (por sus siglas en inglés de phosphate buffered saline) y se retiraron de la solución en diferentes cortes temporales establecidos. Posteriormente, se analizó la concentración de anestésico local en el líquido mediante cromatografía líquida. Resultados: El porcentaje de lidocaína eludida del cemento óseo PMMA de este estudio ha sido del 9,74% del contenido total de lidocaína por espécimen a las 72h y del 18,73% a las 336h (14 días). En el caso de la bupivacaína, el porcentaje de elución ha sido del 2,71% del contenido total de bupivacaína por espécimen a las 72h y del 2,70% a las 336h (14 días). Conclusiones: Los anestésicos locales eluyen in vitro desde el cemento óseo, alcanzando a las 72h dosis cercanas a las dosis utilizadas en bloqueos anestésicos.(AU)

Background and aim: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. Material and methods: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. Results: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). Conclusions: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.(AU)

[Translated article] In vitro elution of local anaesthetics from PMMA bone cement / Estudio in vitro de elución de anestésicos locales en cemento óseo de PMMA

Antecedentes y objetivo:Actualmente, no disponemos de un gold standard para el manejo del dolor postoperatorio tras una artroplastia total de rodilla, dado que se pueden administrar analgésicos a través de diferentes vías y ninguna de estas está exenta de riesgos. El sistema ideal de administración de analgésicos debería proporcionar dosis terapéuticas, no tóxicas, en el sitio quirúrgico, especialmente durante las primeras 72h. El cemento óseo utilizado en las artroplastias se ha usado como un medio de liberación de fármacos, especialmente antibióticos, desde 1970. Basado en este principio, se desarrolló este estudio con el objetivo de conocer el perfil de elución de dos anestésicos locales (hidrocloruro de lidocaína e hidrocloruro de bupivacaína) desde el cemento óseo de polimetilmetacrilato (PMMA). Material y métodos: Se obtuvieron especímenes de cemento óseo Palacos® R+G e hidrocloruro de lidocaína o hidrocloruro de bupivacaína según el grupo de estudio. Estos especímenes se sumergieron en PBS (por sus siglas en inglés de phosphate buffered saline) y se retiraron de la solución en diferentes cortes temporales establecidos. Posteriormente, se analizó la concentración de anestésico local en el líquido mediante cromatografía líquida. Resultados: El porcentaje de lidocaína eludida del cemento óseo PMMA de este estudio ha sido del 9,74% del contenido total de lidocaína por espécimen a las 72h y del 18,73% a las 336h (14 días). En el caso de la bupivacaína, el porcentaje de elución ha sido del 2,71% del contenido total de bupivacaína por espécimen a las 72h y del 2,70% a las 336h (14 días). Conclusiones: Los anestésicos locales eluyen in vitro desde el cemento óseo, alcanzando a las 72h dosis cercanas a las dosis utilizadas en bloqueos anestésicos.(AU)

Background and aim: Currently, we do not have a gold standard for pain management after total knee arthroplasty. We may use one of more drug delivery systems, none of which are ideal. An ideal depot delivery system would provide therapeutic, nontoxic, doses of drug at the surgical side, especially during 72h postoperatively. The bone cement used in arthroplasties has been used as a drug delivery system, especially antibiotics, since 1970. Based on this principle, we developed this study with the aim to characterize the elution profile of two local anesthetics (lidocaine hydrochloride and bupivacaine hydrochloride) from PMMA (polymethilmethacrylate) bone cement. Material and methods: Palacos® R+G bone cement and lidocaine hydrochloride or bupivacaine hydrochloride specimens were obtained depending on the study group. These specimens were immersed in PBS (phosphate buffered saline) and removed from the solution at different set times. Subsequently, the concentration of local anesthetic in the liquid was analyzed by liquid chromatography. Results: The percentage of lidocaine eluted from PMMA bone cement in this study was 9.74% of the total lidocaine content per specimen at 72h and 18.73% at 336h (14 days). In case of bupivacaine, the elution percentage was 2.71% of the total bupivacaine content per specimen at 72h and 2.70% at 336h (14 days). Conclusions: Local anesthetics elute in vitro from PMMA bone cement, reaching doses at 72h close to the doses used in anesthetic blocks.(AU)

M23C6 carbides and Cr2N nitrides in aged duplex stainless steel: A SEM, TEM and FIB tomography investigation.

The precipitation evolution during ageing of a 2101 lean duplex stainless steel was investigated, revealing that the precipitate type and morphology depends on the nature of the grain boundary. Triangular M23C6 carbides precipitate only at γ/δ interfaces and rod-like Cr2N nitrides precipitate at both γ/δ and δ/δ interfaces. After 15min of ageing, the M23C6 size no longer evolves, whereas that of the Cr2N continues to evolve. For Cr2N, the morphology is maintained at γ/δ interfaces, whereas percolation occurs to form a continuous layer at δ/δ interfaces. By combining 2D and 3D characterisation at the nanoscale using transmission electron microscopy (TEM) and focused ion beam (FIB) tomography, a complete description of the precipitation evolution was obtained, including the composition, crystallographic structure, orientation relationship with the matrix phases, location, morphology, size and volume fraction.

Incidence and risk factors of superficial and deep vein thrombosis associated with peripherally inserted central catheters in children.

Essentials Pediatric studies on peripherally inserted central catheter (PICC)-related thrombosis are scarce. This study analyzes incidence and risk factors for PICC-related venous thrombosis in children. PICC-related thrombosis is a common, and nearly always, asymptomatic complication. Echo-guided insertion and a catheter to vein ratio < 0.33 may notably decrease this complication. SUMMARY: Background Upper-extremity venous thrombosis is associated with the use of peripherally inserted central catheters (PICCs). Few pediatric studies have focused on this issue. Objectives To determine the incidence and risk factors for PICC-related superficial vein thrombosis (SVT) and deep vein thrombosis (DVT) in children. Patients/methods An observational follow-up cohort study was conducted at a single hospital between June 2012 and June 2015. All patients receiving a PICC were enrolled and followed up, with weekly Doppler ultrasound examination of the catheterized limb until PICC removal. Patient, procedural and follow-up data were analyzed. Results In the study period, 265 PICCs were inserted (median age of patients 6.5 years, interquartile range [IQR] 2.4-13 years; median weight 20 kg, IQR 11-38 kg; 54% males; 67.9% chronically ill), and patients were followed up for a total of 9743 days. The median indwelling time was 21 days (IQR 12-37 days). During follow-up, 88 (33.2% of insertions) PICC-related thromboses (incidence rate [IR] 9.03 per 1000 catheter-days) were diagnosed, 66 (24.9%) as isolated SVT, seven (2.6%) as isolated DVT, and 15 (5.7%) as SVT with associated DVT (IR 6.78, 0.71 and 1.54 per 1000 catheter-days, respectively). Only 9.9% of patients with SVT and 18.2% of those with DVT were symptomatic. The main risk factors for PICC-related SVT and DVT were a catheter/vein ratio of > 0.33 and thrombosis of the catheterized superficial vein, respectively. Conclusions PICC-related thrombosis is a common and nearly always asymptomatic complication in children, the SVT rate being approximately three times higher than the DVT rate. Optimal vein and catheter selection, yielding the lowest possible catheter/vein ratio, may decrease the rate of PICC-related thrombosis.