Impacto clínico de no aplicar el protocolo ERAS en los pacientes sometidos a cistectomía durante la pandemia COVID-19 / Clinical impact of the suspension of the ERAS protocol on patients undergoing radical cystectomy during the COVID-19 pandemic

Introducción Al inicio de la pandemia por COVID-19 no se pudo implementar ni prehabilitación ni rehabilitación multimodal por sobrecarga del sistema sanitario. Nuestro objetivo fue analizar evolución, complicaciones y supervivencia hasta el año de pacientes sometidos a cistectomía radical en nuestro centro desde el 1 de marzo hasta el 31 de mayo de 2020 (primera ola). Comparamos resultados con pacientes también cistectomizados fuera de pandemia donde sí estaba instaurado el protocolo ERAS. Material y métodos Estudio de cohortes retrospectivo, unicéntrico, de pacientes programados para cistectomía radical desde el 1 de marzo de 2020 hasta el 31 de mayo de 2020; se emparejaron con pacientes intervenidos anteriormente a través de score de emparejamiento por propensión 1:2. Las variables de emparejamiento fueron datos demográficos, condiciones clínicas preoperatorias e intraoperatorias. Resultados Se realizaron 23 cistectomía en este periodo; en ningún caso se aplicó ni prehabilitación ni seguimiento del protocolo ERAS, y esta fue la única diferencia en el tratamiento entre grupos. Tres pacientes se diagnosticaron de COVID-19 durante su ingreso presentando complicaciones respiratorias graves y alta mortalidad intrahospitalaria. La tasa de transfusión sanguínea fue mayor en el grupo pandemia. La estancia hospitalaria aumentó en tres días en grupo pandemia. Conclusiones Los pacientes sometidos a cistectomía en nuestro centro durante la primera ola de pandemia por COVID-19 presentaron complicaciones respiratorias y no respiratorias en mayor número y más graves que los cistectomizados fuera de este periodo. La no aplicación del protocolo ERAS fue la principal diferencia en el tratamiento entre grupos (AU)

Introduction During the beginning of the COVID-19 pandemic in our center, neither prehabilitation nor multimodal rehabilitation could be applied due to the excessive patient load on the health system and to reduce SARS-CoV-2 transmission. The objective of our study was to analyze the evolution, complications, and survival up to one year of patients who underwent radical cystectomy in our hospital from March 1st to May 31st, 2020 (period of the first wave COVID-19 pandemic in Spain). We also compared the results with cystectomized patients outside the pandemic period and with application of the ERAS (Enhanced Recovery After Surgery) protocol. Material and methods Single-center, retrospective cohort study of patients scheduled for radical cystectomy from March 1st,2020 to May 31st, 2020. They were matched with previously operated patients using a 1:2 propensity matching score. The matching variables were demographic data, preoperative and intraoperative clinical conditions. Results A total of 23 radical cystectomies with urinary diversion were performed in the period described. In none of the cases the prehabilitation or the follow-up of our ERAS protocol could be applied, and this was the only difference we found between the 2 groups. Although the minimally invasive approach was more frequent in the pandemic group, the difference was not statistically significant. Three patients were diagnosed with COVID-19 during their admission, presenting severe respiratory complications and high in-hospital mortality. Apart from respiratory complications secondary to SARS-CoV-2, we also found statistically significant differences in other postoperative complications. The hospital stay increased by 3 days in the pandemic group (AU)

Enterotoxemia produced by lambda toxin-positive Clostridium perfringens type D in 2 neonatal goat kids.

Enterotoxemia caused by Clostridium perfringens type D usually affects sheep and goats ≥ 2-wk-old. The main clinical signs and lesions of the disease are produced by the epsilon toxin (ETX) elaborated by this microorganism. However, ETX is produced in the form of a mostly inactive prototoxin that requires protease cleavage for activation. It has traditionally been believed that younger animals are not affected by type D enterotoxemia given the low trypsin activity in the intestinal content associated with the trypsin-inhibitory action of colostrum. Two Nigerian dwarf goat kids, 2- and 3-d-old, with a history of acute diarrhea followed by death, were submitted for postmortem examination and diagnostic workup. Autopsy and histopathology revealed mesocolonic edema, necrosuppurative colitis, and protein-rich pulmonary edema. Alpha toxin and ETX were detected in intestinal content, and C. perfringens type D was isolated from the colon of both animals. The isolates encoded the gene for lambda toxin, a protease that has been shown previously to activate ETX in vitro. Type D enterotoxemia has not been reported previously in neonatal kids, to our knowledge, and we suggest that lambda toxin activated the ETX.

[CLINICAL IMPACT OF THE SUSPENSION OF THE ERAS PROTOCOL ON PATIENTS UNDERGOING RADICAL CYSTECTOMY DURING THE COVID-19 PANDEMIC.] / IMPACTO CLÍNICO DE NO APLICAR EL PROTOCOLO ERAS EN LOS PACIENTES SOMETIDOS A CISTECTOMÍA DURANTE LA PANDEMIA COVID-19.

INTRODUCTION: During the beginning of the COVID-19 pandemic in our center, neither prehabilitation nor multimodal rehabilitation could be applied due to the excessive patient load on the health system and to reduce SARS-CoV-2 transmission. The objective of our study was to analyze the evolution, complications, and survival up to one year of patients who underwent radical cystectomy in our hospital from March 1st to May 31st, 2020 (period of the first wave COVID-19 pandemic in Spain). We also compared the results with cystectomized patients outside the pandemic period and with application of the ERAS (Enhanced Recovery After Surgery) protocol. MATERIAL AND METHODS: Single-center, retrospective cohort study of patients scheduled for radical cystectomy from March 1st,2020 to May 31st, 2020. They were matched with previously operated patients using a 1:2 propensity matching score. The matching variables were demographic data, preoperative and intraoperative clinical conditions. RESULTS: A total of 23 radical cystectomies with urinary diversion were performed in the period described. In none of the cases the prehabilitation or the follow-up of our ERAS protocol could be applied, and this was the only difference we found between the 2 groups. Although the minimally invasive approach was more frequent in the pandemic group, the difference was not statistically significant. Three patients were diagnosed with COVID-19 during their admission, presenting severe respiratory complications and high in-hospital mortality. Apart from respiratory complications secondary to SARS-CoV-2, we also found statistically significant differences in other postoperative complications. The hospital stay increased by 3 days in the pandemic group. CONCLUSIONS: Patients who underwent radical cystectomy at our center during the first wave of the COVID-19 pandemic had a higher number and severity of respiratory and non-respiratory complications. Discontinuation of the ERAS protocol was the main difference in treatment between groups.

Colonic T-cell-rich, large B-cell lymphoma associated with equid herpesvirus 5 infection and secondary trans-colonic fistula in a horse.

A 17-y-old Rocky Mountain gelding was presented to the Virginia-Maryland Veterinary Teaching Hospital because of a 4-wk history of anorexia, weight loss, lethargy, and fever of unknown origin. Abdominal ultrasound revealed lymphadenomegaly of the abdominal and colonic lymph nodes, thickening of the wall of the large colon, and a mass associated with the large colon. The horse was euthanized given a poor prognosis. On autopsy, an ~20-cm diameter mass was found within the mesocolon between the right ventral and right dorsal colon. The mass had invaded through the colonic walls and formed a fistula between the 2 involved lumina. On histologic evaluation, the mass consisted of small numbers of large neoplastic lymphocytes, numerous small lymphocytes, and many foamy macrophages. A diagnosis of T-cell-rich, large B-cell lymphoma was made based on immunohistochemical staining for CD79a, CD3, and Iba1; concurrent infection with equid herpesvirus 5 was confirmed with in-situ hybridization (ISH). To our knowledge, neither a trans-colonic fistula resulting from alimentary lymphoma in a horse nor detection of intralesional equid herpesvirus 5 in equine alimentary lymphoma by ISH has been reported previously.

Clinical impact of the suspension of the ERAS protocol on patients undergoing radical cystectomy during the COVID-19 pandemic.

INTRODUCTION: During the beginning of the COVID-19 pandemic in our center, neither prehabilitation nor multimodal rehabilitation could be applied due to the excessive patient load on the health system and to reduce SARS-CoV-2 transmission. The objective of our study was to analyze the evolution, complications, and survival up to one year of patients who underwent radical cystectomy in our hospital from March 1st to May 31st, 2020 (period of the first wave COVID-19 pandemic in Spain). We also compared the results with cystectomized patients outside the pandemic period and with application of the ERAS (Enhanced Recovery After Surgery) protocol. MATERIAL AND METHODS: Single-center, retrospective cohort study of patients scheduled for radical cystectomy from March 1st, 2020 to May 31st, 2020. They were matched with previously operated patients using a 1:2 propensity matching score. The matching variables were demographic data, preoperative and intraoperative clinical conditions. RESULTS: A total of 23 radical cystectomies with urinary diversion were performed in the period described. In none of the cases the prehabilitation or the follow-up of our ERAS protocol could be applied, and this was the only difference we found between the 2 groups. Although the minimally invasive approach was more frequent in the pandemic group, the difference was not statistically significant. Three patients were diagnosed with COVID-19 during their admission, presenting severe respiratory complications and high in-hospital mortality. Apart from respiratory complications secondary to SARS-CoV-2, we also found statistically significant differences in other postoperative complications. The hospital stay increased by 3 days in the pandemic group. CONCLUSIONS: Patients who underwent radical cystectomy at our center during the first wave of the COVID-19 pandemic had a higher number and severity of respiratory and non-respiratory complications. Discontinuation of the ERAS protocol was the main difference in treatment between groups.

Opportunistic Use of Lumbar Magnetic Resonance Imaging for Osteoporosis Screening.

Magnetic resonance imaging (MRI) is a routine assessment before spine surgery. We found that the opportunistic use of MRI with the vertebral bone quality (VBQ) score has good diagnostic ability, with a threshold value of VBQ > 3.0, in recognizing patients who may need further osteoporosis evaluation. INTRODUCTION: The purpose of this study was to determine whether the opportunistic use of magnetic resonance imaging (MRI) is useful for identifying spine surgical patients who need further osteoporosis evaluation. METHODS: This retrospective study evaluated 83 thoracolumbar spine surgery patients age ≥ 50 who received T1-weighted MRI. Opportunistic MRI was evaluated with the vertebral bone quality (VBQ) score, VBQ (fat) score, and signal-to-noise ratio (SNR). Each uses the median L1-L4 vertebral body signal intensities (SI) divided by either the L3 cerebrospinal fluid (CSF) SI, average SI of the L1 and S1 dorsal fat, or standard deviation (SD) of the background SI dorsal to the skin. Single-level VBQ was calculated as the ratio of the L1 vertebral body and L1 CSF SIs. Receiver-operator curve analysis was performed to determine diagnostic ability. RESULTS: The mean age was 70.10, 80% were female, and 96% were Caucasian. The mean ± SD VBQ, single-level VBQ, VBQ (fat), and SNR were 3.39 ± 0.68, 3.56 ± 0.81, 3.95 ± 1.89, and 113.18 ± 77.26, respectively. Using area under the curve, the diagnostic ability of VBQ, single-level VBQ, VBQ (fat), and SNR for clinical osteoporosis were 0.806, 0.779, 0.608, and 0.586, respectively. Diagnostic threshold values identified with optimal sensitivity and specificity were VBQ of 2.95 and single-level VBQ of 3.06. CONCLUSION: Opportunistic use of MRI is a simple, effective tool that may help recognize patients who are at risk for complications related to bone disease. A VBQ > 3.0 can identify patients who need additional diagnostic evaluation.

Reproducibility of liver R2* quantification for liver iron quantification from cardiac R2* acquisitions.

OBJECTIVES: To evaluate the reproducibility of liver R2* measurements between a 2D cardiac ECG-gated and a 3D breath-hold liver CSE-MRI acquisition for liver iron quantification. METHODS: A total of 54 1.5 T MRI exams from 51 subjects (18 women, 36 men, age 35.2 ± 21.8) were included. These included two sub-studies with 23 clinical MRI exams from 19 patients identified retrospectively, 24 participants with known or suspected iron overload, and 7 healthy volunteers acquired prospectively. The 2D cardiac and the 3D liver R2* maps were acquired in the same exam. Either acquisitions were reconstructed using a complex R2* algorithm that accounts for the presence of fat and residual phase errors due to eddy currents. Data were analyzed using colocalized ROIs in the liver. RESULTS: Linear regression analysis demonstrated high Pearson's correlation and Lin's concordance coefficient for the overall study and both sub-studies. Bland-Altman analysis also showed good agreement, except for a slight increase of the mean R2* value above ~ 400 s-1. The Kolmogorow-Smirnow test revealed a non-normal distribution for (R2* 3D-R2* 2D) values from 0 to 600 s-1 in contrast to the 0-200 s-1 and 0-400 s-1 subpopulations. Linear regression analysis showed no relevant differences other than the intercept, likely due to only 7 measurements above 400 s-1. CONCLUSIONS: The results demonstrate that R2*-measurements in the liver are feasible using 2D cardiac R2* maps compared to 3D liver R2* maps as the reference. Liver R2* may be underestimated for R2* > 400 s-1 using the 2D cardiac R2* mapping method.

Endotoxin Engages Mitochondrial Quality Control via an iNOS-Reactive Oxygen Species Signaling Pathway in Hepatocytes.

BACKGROUND: Organ injury and dysfunction in sepsis accounts for significant morbidity and mortality. Adaptive cellular responses in the setting of sepsis prevent injury and allow for organ recovery. We and others have shown that part of the adaptive response includes regulation of cellular respiration and maintenance of a healthy mitochondrial population. Herein, we hypothesized that endotoxin-induced changes in hepatocyte mitochondrial respiration and homeostasis are regulated by an inducible nitric oxide synthase/nitric oxide (iNOS/NO)-mitochondrial reactive oxygen species (mtROS) signaling axis, involving activation of the NRF2 signaling pathway. METHODS: Wild-type (C57Bl/6) or iNos-/- male mice were subjected to intraperitoneal lipopolysaccharide (LPS) injections to simulate endotoxemia. Individual mice were randomized to treatment with NO-releasing agent DPTA-NONOate, mtROS scavenger MitoTEMPO, or vehicle controls. Other mice were treated with scramble or Nrf2-specific siRNA via tail vein injection. Primary murine hepatocytes were utilized for in vitro studies with or without LPS stimulation. Oxygen consumption rates were measured to establish mitochondrial respiratory parameters. Western blotting, confocal microscopy with immunocytochemistry, and rtPCR were performed for analysis of iNOS as well as markers of both autophagy and mitochondrial biogenesis. RESULTS: LPS treatment inhibited aerobic respiration in vitro in wild-type but not iNos -/- cells. Experimental endotoxemia in vivo or in vitro induced iNOS protein and mtROS production. However, induction of mtROS was dependent on iNOS expression. Furthermore, LPS-induced hepatic autophagy/mitophagy and mitochondrial biogenesis were significantly attenuated in iNos -/- mice or cells with NO or mtROS scavenging. These responses were rescued in iNos -/- mice via delivery of NO both in vivo and in vitro. Conclusions. These data suggest that regulation of mitochondrial quality control following hepatocyte LPS exposure is dependent at least in part on a NO-mtROS signaling network. Further investigation to identify specific agents that modulate this process may facilitate the prevention of organ injury in sepsis.

Coaxial nanowires as plasmon-mediated remote nanosensors.

This study reports on the plasmon-mediated remote Raman sensing promoted by specially designed coaxial nanowires. This unusual geometry for Raman study is based on the separation, by several micrometres, of the excitation laser spot, on one tip of the nanowire, and the Raman detection at the other tip. The very weak efficiency of Raman emission makes it challenging in a remote configuration. For the proof-of-concept, we designed coaxial nanowires consisting of a gold core to propagate surface plasmon polaritons and a Raman-emitting shell of poly(3,4-ethylene-dioxythiophene). The success of the fabrication was demonstrated by correlating, for the same single nanowire, a morphological analysis by electron microscopy and Raman spectroscopy analysis. Importantly for probing the remote-Raman effect, the original hard template-based process allows one to control the location of the polymer shell all along the nanowire, or only close to one or the two nanowire tips. Such all-in-one single nanowires could have applications in the remote detection of photo-degradable substances and for exploring 1D nanosources for integrated photonic and plasmonic systems.

Identification of patients prone to hypotension during hemodialysis based on the analysis of cardiovascular signals.

Intradialytic hypotension (IDH) is a major complication during hemodialysis treatment, and therefore it is highly desirable to identify, at an early stage during treatment, whether the patient is prone to IDH. Heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS) were analyzed during the first 30 min of treatment to assess information on the autonomic nervous system. Using the sequential floating forward selection method and linear classification, the set of features with the best discriminative power was selected, resulting in an accuracy of 92.1%. Using a classifier based on the HRV features only, thereby avoiding that continuous blood pressure has to be recorded, accuracy decreased to 90.2%. The results suggest that an HRV-based classifier is useful for determining whether a patient is prone to IDH at the beginning of the treatment.

Manejo anestésico del síndrome de Stiff Man / Anaesthetic management of Stiff Man syndrome

El síndrome de Stiff Man o síndrome de la persona rígida es una enfermedad rara de causa inmunológica. Se caracteriza por la rigidez en la musculatura axial y las extremidades inferiores, y espasmos dolorosos desencadenados por estímulos. Presentamos el caso de un paciente de 44 años con síndrome de la persona rígida al que se le realizó una infiltración del esfínter uretral con toxina botulínica bajo sedación. Antes de la inducción anestésica todo el equipo quirúrgico estuvo preparado con el objetivo de minimizar el tiempo anestésico. Se realizó una monitorización continua de ECG, SpO2 por pulsioximetría y presión no invasiva. Fue inducido con dosis fraccionadas de propofol hasta 150 mg, fentanilo 50 μg y midazolam 1 mg. A pesar de las dosis bajas y fraccionadas el paciente presentó una desaturación máxima del 90% que fue resuelta con ventilación manual. Durante la intervención no hubo episodios de espasmos ni de rigidez muscular. El paciente fue dado de alta 2 días después, sin incidencias. Aprovechamos el caso para revisar aquellos publicados hasta la fecha sobre este tema. El interés sobre el manejo anestésico de estos pacientes viene dado por las interacciones entre la medicación preoperatoria, los fármacos anestésicos y el sistema GABA. Recomendamos el uso de la anestesia total intravenosa frente a los agentes anestésicos inhalatorios, la vigilancia estrecha de la función respiratoria y el uso de la monitorización neuromuscular cuando sean utilizados relajantes musculares para un manejo anestésico más seguro (AU)

Stiff Man syndrome or stiff-person syndrome is a rare autoimmune disorder. It is characterized by increased axial muscular tone and limb musculature, and painful spasms triggered by stimulus. The case is presented of a 44-year-old man with stiff-person syndrome undergoing an injection of botulinum toxin in the urethral sphincter under sedation. Before induction, all the surgical team were ready in order to minimise the anaesthetic time. The patient was monitored by continuous ECG, SpO2 and non-invasive blood pressure. He was induced with fractional dose of propofol 150 mg, fentanyl 50 μg and midazolam 1 mg. Despite careful titration, the patient had an O2 saturation level of 90%, which was resolved by manual ventilation. There was no muscle rigidity or spasm during the operation. Post-operative recovery was uneventful and the patient was discharged 2 days later. A review of other cases is presented. The anaesthetic concern in patients with stiff-person syndrome is the interaction between the anaesthetic agents, the preoperative medication, and the GABA system. For a safe anaesthetic management, total intravenous anaesthesia is recommended instead of inhalation anaesthetics, as well as the close monitoring of the respiratory function and the application of the electrical nerve stimulator when neuromuscular blockers are used (AU)

[Anaesthetic management of Stiff Man syndrome]. / Manejo anestésico del síndrome de Stiff Man.

Stiff Man syndrome or stiff-person syndrome is a rare autoimmune disorder. It is characterized by increased axial muscular tone and limb musculature, and painful spasms triggered by stimulus. The case is presented of a 44-year-old man with stiff-person syndrome undergoing an injection of botulinum toxin in the urethral sphincter under sedation. Before induction, all the surgical team were ready in order to minimise the anaesthetic time. The patient was monitored by continuous ECG, SpO2 and non-invasive blood pressure. He was induced with fractional dose of propofol 150 mg, fentanyl 50 µg and midazolam 1mg. Despite careful titration, the patient had an O2 saturation level of 90%,which was resolved by manual ventilation. There was no muscle rigidity or spasm during the operation. Post-operative recovery was uneventful and the patient was discharged 2 days later. A review of other cases is presented. The anaesthetic concern in patients with stiff-person syndrome is the interaction between the anaesthetic agents, the preoperative medication, and the GABA system. For a safe anaesthetic management, total intravenous anaesthesia is recommended instead of inhalation anaesthetics, as well as the close monitoring of the respiratory function and the application of the electrical nerve stimulator when neuromuscular blockers are used.

Attenuation of the influence of cardiolocomotor coupling in heart rate variability interpretation during exercise test.

During exercise test, cardiolocomotor coupling related components appear in heart rate variability (HRV), blurring its interpretation as autonomic nervous system (ANS) marker. These cardiolocomotor coupling related components are centered at the pedalling and running stride frequency, as well as at their aliases, and may overlap with the low frequency (LF) and high frequency (HF) components of HRV. In this work cardiolocomotor-related HRV components are studied during maximal exercise test on treadmill and cycle ergometer. Power in the bands related to cardiolocomotor coupling increases with exercise intensity in cycle ergometer but not in treadmill exercise test, where it displays higher values for all exercise intensities. A method is proposed to reduce the effect of this coupling in the interpretation of HRV. Evolution of the power in the low frequency (LF) and high frequency (HF) bands are studied after the proposed reduction of cardiolocomotor coupling, showing more significant changes with exercise intensity than before the method is applied.

Addressing phase errors in fat-water imaging using a mixed magnitude/complex fitting method.

Accurate, noninvasive measurements of liver fat content are needed for the early diagnosis and quantitative staging of nonalcoholic fatty liver disease. Chemical shift-based fat quantification methods acquire images at multiple echo times using a multiecho spoiled gradient echo sequence, and provide fat fraction measurements through postprocessing. However, phase errors, such as those caused by eddy currents, can adversely affect fat quantification. These phase errors are typically most significant at the first echo of the echo train, and introduce bias in complex-based fat quantification techniques. These errors can be overcome using a magnitude-based technique (where the phase of all echoes is discarded), but at the cost of significantly degraded signal-to-noise ratio, particularly for certain choices of echo time combinations. In this work, we develop a reconstruction method that overcomes these phase errors without the signal-to-noise ratio penalty incurred by magnitude fitting. This method discards the phase of the first echo (which is often corrupted) while maintaining the phase of the remaining echoes (where phase is unaltered). We test the proposed method on 104 patient liver datasets (from 52 patients, each scanned twice), where the fat fraction measurements are compared to coregistered spectroscopy measurements. We demonstrate that mixed fitting is able to provide accurate fat fraction measurements with high signal-to-noise ratio and low bias over a wide choice of echo combinations.

Removal of olefinic fat chemical shift artifact in diffusion MRI.

Diffusion-weighted (DW) MRI has emerged as a key tool for assessing the microstructure of tissues in healthy and diseased states. Because of its rapid acquisition speed and insensitivity to motion, single-shot echo-planar imaging is the most common DW imaging technique. However, the presence of fat signal can severely affect DW-echo planar imaging acquisitions because of the chemical shift artifact. Fat suppression is usually achieved through some form of chemical shift-based fat saturation. Such methods effectively suppress the signal originating from aliphatic fat protons, but fail to suppress the signal from olefinic protons. Olefinic fat signal may result in significant distortions in the DW images, which bias the subsequently estimated diffusion parameters. This article introduces a method for removing olefinic fat signal from DW images, based on an echo time-shifted acquisition. The method is developed and analyzed specifically in the context of single-shot DW-echo-planar imaging, where image phase is generally unreliable. The proposed method is tested with phantom and in vivo datasets, and compared with a standard acquisition to demonstrate its performance.

Absorción peritoneal de líquido de irrigación vesical / No disponible

No disponible

Spin-orbit-mediated spin relaxation in graphene.

We investigate how spins relax in intrinsic graphene. The spin-orbit coupling arises from the band structure and is enhanced by ripples. The orbital motion is influenced by scattering centers and ripple-induced gauge fields. Spin relaxation due to Elliot-Yafet and Dyakonov-Perel mechanisms and gauge fields in combination with spin-orbit coupling are discussed. In intrinsic graphene, the Dyakonov-Perel mechanism and spin flip due to gauge fields dominate and the spin-flip relaxation time is inversely proportional to the elastic scattering time. The spin-relaxation anisotropy depends on an intricate competition between these mechanisms. Experimental consequences are discussed.

Antiagregación perioperatoria en pacientes portadores de stent coronario convencional y farmacoactivo / No disponible

La intervención coronaria percutánea (ICP) comenzó a realizarse a mediados de los años 80 como alternativa a la cirugía de derivación aortocoronaria en pacientes con cardiopatía isquémica. A finales de los años 90 ya se habían llevado a cabo a nivel mundial más de un millón de procedimientos percutáneos. Cada vez es más frecuente que se someta a pacientes portadores de stents coronarios y en tratamiento antiagregante a cirugía urológica. En estos casos nos enfrentamos al dilema de suspender los antiagregantes previamente a la cirugía para evitar el riesgo de sangrado o bien, mantener el tratamiento para evitar el riesgo de complicaciones cardiovasculares por trombosis en el postoperatorio. Se debe mantener la aspirina siempre que sea posible y demorar la cirugía si es electiva hasta pasado el tiempo de seguridad desde el implante que es mayor de 6 semanas en los stent convencionales y mayor a un año en los stent farmacoactivos. Al valorar el riesgo-beneficio de la antiagregación, creemos pertinente individualizar cada caso, tomando estas recomendaciones como guía, a fin de reducir la morbimortalidad perioperatoria y a largo plazo por trombosis del stent (AU)

Percutaneous coronary intervention began to be realized in the middle of the 80s as an alternative to aortocoronary surgery in patients with ischemic cardiopathy. At the end of the 90s, more than 1 million of percutaneous procedures had been carried out around the world. As time passes by, it is more frequent to treat patients carrying coronary stents and in double antiaggregation agent therapy to urologic surgery. In these cases we face the dilemma to stop the antiplatelet agent therapy previous to the surgery to avoid the bleeding risk or, to maintain the treatment to avoid the risk of cardiovascular complications by thrombosis in the post-operatory period. Aspirin must be maintained whenever it is possible and we should delay the elective surgery until the security time is spent form implants greater than 6 weeks in conventional stents and greater than a year in farmacoactive stents. When valuing risk-be-nefit form the antiaggregation therapy, we believe pertinent to individualize each case, taking these recommendations as a guide, in order to reduce to the mobility and mortality in the perioperatory period and in long term by thrombosis in these patients (AU)

Joint estimation of water/fat images and field inhomogeneity map.

Water/fat separation in the presence of B 0 field inhomogeneity is a problem of considerable practical importance in MRI. This article describes two complementary methods for estimating the water/fat images and the field inhomogeneity map from Dixon-type acquisitions. One is based on variable projection (VARPRO) and the other on linear prediction (LP). The VARPRO method is very robust and can be used in low signal-to-noise ratio conditions because of its ability to achieve the maximum-likelihood solution. The LP method is computationally more efficient, and is shown to perform well under moderate levels of noise and field inhomogeneity. These methods have been extended to handle multicoil acquisitions by jointly solving the estimation problem for all the coils. Both methods are analyzed and compared and results from several experiments are included to demonstrate their performance.