The use of the acute Pd/Pa drop after intracoronary nitroglycerin infusion to rule out significant FFR: CANICA (Can intracoronary nitroglycerin predict fractional flow reserve without adenosine?) multicenter study.

OBJECTIVE: Functional assessment of coronary artery stenosis is performed by measuring the fractional flow reserve (FFR) under hyperemic conditions (Adenosine). However, the use of adenosine portends limitations. OBJECTIVE: We sought to investigate the relationship and correlation between FFR and the Pd/Pa value obtained just after the intracoronary infusion (acute drop) of nitroglycerin (Pd/Pa-NTG) and if this parameter enhances diagnostic accuracy for FFR prediction compared to the resting baseline Pd/Pa. METHODS: We conducted a multicenter study including prospectively patients presenting intermediate coronary artery stenosis (30-70%) evaluated with pressure wire. Resting baseline Pd/Pa, Pd/Pa-NTG and FFR were measured. RESULTS: 283 patients (335 lesions) were included. Resting baseline Pd/Pa value was 0.72 to 1.0 (0.93 ± 0.04), Pd/Pa-NTG was 0.60 to 1.0 (0.87 ± 0.07) and FFR 0.55 to 1.0 (0.83 ± 0.08). The ROC curves for resting baseline Pd/Pa and for Pd/Pa-NTG, using a FFR ≤ 0.80 showed an AUC of 0.88 (95% CI: 0.84-0.92, P < 0.001) and 0.94 (95% CI: 0.92-0.96, P < 0.001) respectively. The optimal cutoff values of resting baseline Pd/Pa and Pd/Pa-NTG for an FFR > 0.80, were >0.96 and >0.88, respectively. These values were present in a 29.8% (n = 100) and a 47.1% (n = 158), of the total lesions. Scatter plots showed a better correlation and agreement points with Pd/Pa-NTG than resting baseline Pd/Pa. The cutoff value of Pd/Pa-NTG > 0.88 showed an excellent NPV (96.2% for FFR > 0.8 and 100% for FFR > 0.75) and sensitivity (95% for FFR > 0.8 and 100% for FFR > 0.75) which were consistently high across all the subgroups analysis. CONCLUSION: The cutoff value of acute Pd/Pa-NTG > 0.88 has a high NPV meaning adenosine-FFR can be avoided in almost half of lesions.

Changes in the dynamics of Coxiella burnetii infection in dairy cattle: an approach to match field data with the epidemiological cycle of C. burnetii in endemic herds.

This study aimed to evaluate changes in the epidemiological status of Coxiella burnetii in dairy cattle herds to better understand the epidemiology of the infection and to predict its evolution. Bulk-tank milk (BTM) and serum samples were collected from 94 dairy cattle herds and analyzed by ELISA (BTM and sera) and PCR (BTM) in study 1 (S1). Two years later (study 2; S2), the same farms were visited with a similar sampling approach. To estimate seroconversion during this period, blood samples were collected from the maximum possible number of animals surveyed in S1. Environmental samples were collected in S2 to identify active shedding. Farms were allocated into 3 different categories in each study according to PCR and ELISA results: category A, with BTM ELISA and PCR positive herds and at least 1 seropositive animal; category B, with BTM ELISA or PCR positive herds or individual sera positive; and category C, with all negative results among herds. Changes in herd category between S1 and S2 were grouped in 9 classes. Two statistical models, one to search for drives of within-herd changes in C. burnetii infection status and another to look for variables modulating individual changes in C. burnetii antibody level, were built. Several herds in category A in S1 remained in that category 2 yr later, indicating that C. burnetii can remain within a herd for a long time. Most of the herds with seroconversion and detection of the bacterium in the environment belonged to category A, suggesting active and recent infections. Changes in the epidemiological status of herds were driven by local densities of domestic ruminants, showing the implication of neighbor reservoirs; whereas individual changes in antibody levels were modulated by variation in the epidemiological status of herds. Observed changes in epidemiological status allowed depiction of the hypothesized life cycle of C. burnetii within dairy cattle herds, which should be tested by future long-term series studies on C. burnetii infection to help fitting control measures (e.g., vaccination) to within-herd C. burnetii status.

Modified hyperspheres algorithm to trace homotopy curves of nonlinear circuits composed by piecewise linear modelled devices.

We present a homotopy continuation method (HCM) for finding multiple operating points of nonlinear circuits composed of devices modelled by using piecewise linear (PWL) representations. We propose an adaptation of the modified spheres path tracking algorithm to trace the homotopy trajectories of PWL circuits. In order to assess the benefits of this proposal, four nonlinear circuits composed of piecewise linear modelled devices are analysed to determine their multiple operating points. The results show that HCM can find multiple solutions within a single homotopy trajectory. Furthermore, we take advantage of the fact that homotopy trajectories are PWL curves meant to replace the multidimensional interpolation and fine tuning stages of the path tracking algorithm with a simple and highly accurate procedure based on the parametric straight line equation.

Estimation of Coxiella burnetii prevalence in dairy cattle in intensive systems by serological and molecular analyses of bulk-tank milk samples.

A large-scale investigation on Coxiella burnetii was carried out in dairy cattle herds from a Q fever-endemic region to evaluate the degree of exposure to C. burnetii and to estimate prevalences. This study included all of the dairy cattle herds from the province of Bizkaia, Northern Spain (n=178). Herds were visited between September 2009 and February 2010, and 100mL of bulk-tank milk (BTM) per farm was collected to be analyzed by ELISA and PCR. Blood samples were also taken from about 15 animals randomly selected from each herd. One hundred nineteen of the 178 studied herds (66.9±6.9%) were positive for the presence of anti-C. burnetii antibodies in BTM. Serum samples from 1,306 cows, 654 heifers, and 502 calves were analyzed by ELISA, and cows showed a statistically significantly higher seroprevalence (12.3±1.8%) than heifers (1.1±0.8%) and calves (0.0±0.0%). Eighty-nine herds (50.0±7.3%) had at least 1 seropositive animal, but within-herd prevalences higher than 20% were only observed in 24 herds (13.5±5.0%). A significant correlation was observed between BTM ELISA sample-to-positive control ratios and within-herd seroprevalence, being higher when considering only cows (R(2)=0.21). Animals from herds with negative BTM by ELISA showed a mean seroprevalence of 2.5%, whereas animals from herds with positive BTM samples had a statistically significantly higher seroprevalence (8.9%, F=19.7, degrees of freedom=1). The proportion of herds C. burnetii positive by BTM PCR was 51.7±7.3% (92/178). The widespread distribution of C. burnetii in cattle advocates for the implementation of Q fever control strategies.

Evaluating the impact of the learning curve on the perioperative outcomes of robot-assisted radical cystectomy with intracorporeal urinary diversion.

INTRODUCTION: Robot-assisted radical cystectomy (RARC) with intracorporeal urinary diversion (ICUD) is a technically difficult procedure. Our aim was to evaluate the potential impact of the learning curve (LC) on perioperative and pathological outcomes of RARC with ICUD. MATERIAL AND METHODS: Retrospective study of 62 consecutive patients who underwent RARC with ICUD for bladder cancer between 2015-2020. We compared 3 consecutive groups of 20 (G1), 20 (G2), and 22 (G3) patients to analyze the impact of the LC. G1 cases were performed by a senior surgeon experienced in robotic surgery, while G2-G3 were performed by 2 junior surgeons without experience under the mentorship of the senior surgeon. RESULTS: The 3 groups had similar clinical and pathological characteristics. A total of 15 patients (24%) received a neobladder and 47 (75%) an ileal conduit. The mean operative time decreased 60 min between G1-G3 (p = 0.001). No conversions to open approach or intraoperative complications were reported. There were no differences between groups regarding positive margin rates (p = 0.6) or the number of lymph nodes removed (p = 0.061). The postoperative complication rate was 77% and did not change during the LC (p = 0.49). Uretero-enteric stricture rate decreased from 25% in G1 to 9% in G3 (p = 0.217). CONCLUSIONS: The inclusion of junior surgeons to a RARC with ICUD program after the initial 20 cases does not have an impact on the perioperative and pathological outcomes of the procedure. The operative time and the uretero-enteric stricture rate could be reduced during the LC.

Predictive factors of six-week mortality in critically ill patients with SARS-CoV-2: A multicenter prospective study.

OBJECTIVE: The objective of the study is to identify the risk factors associated with mortality at six weeks, especially by analyzing the role of antivirals and munomodulators. DESIGN: Prospective descriptive multicenter cohort study. SETTING: 26 Intensive care units (ICU) from Andalusian region in Spain. PATIENTS OR PARTICIPANTS: Consecutive critically ill patients with confirmed SARS-CoV-2 infection were included from March 8 to May 30. INTERVENTIONS: None. VARIABLES: Variables analyzed were demographic, severity scores and clinical condition. Support therapy, drug and mortality were analyzed. An univariate followed by multivariate Cox regression with propensity score analysis was applied. RESULTS: 495 patients were enrolled, but 73 of them were excluded for incomplete data. Thus, 422 patients were included in the final analysis. Median age was 63 years and 305 (72.3%) were men. ICU mortality: 144/422 34%; 14 days mortality: 81/422 (19.2%); 28 days mortality: 121/422 (28.7%); 6-week mortality 152/422 36.5%. By multivariable Cox proportional analysis, factors independently associated with 42-day mortality were age, APACHE II score, SOFA score at ICU admission >6, Lactate dehydrogenase at ICU admission >470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission <6.5%, and thrombocytopenia whereas the use of lopinavir/ritonavir was a protective factor. CONCLUSION: Age, APACHE II, SOFA>value of 6 points, along with vasopressor requirements or renal replacement therapy have been identified as predictor factors of mortality at six weeks. Administration of corticosteroids showed no benefits in mortality, as did treatment with tocilizumab. Lopinavir/ritonavir administration is identified as a protective factor.

Evaluating the impact of the learning curve on the perioperative outcomes of robot-assisted radical cystectomy with intracorporeal urinary diversion. / Análisis del impacto de la curva de aprendizaje de la cistectomía radical asistida por robot con derivación urinaria intracorpórea sobre los resultados perioperatorios.

INTRODUCTION: Robot-assisted radical cystectomy (RARC) with intracorporeal urinary diversion (ICUD) is a technically difficult procedure. Our aim was to evaluate the potential impact of the learning curve (LC) on perioperative and pathological outcomes of RARC with ICUD. MATERIAL AND METHODS: Retrospective study of 62 consecutive patients who underwent RARC with ICUD for bladder cancer between 2015-2020. We compared 3 consecutive groups of 20 (G1), 20 (G2), and 22 (G3) patients to analyze the impact of the LC. G1 cases were performed by a senior surgeon experienced in robotic surgery, while G2-G3 were performed by 2 junior surgeons without experience under the mentorship of the senior surgeon. RESULTS: The 3 groups had similar clinical and pathological characteristics. A total of 15 patients (24%) received a neobladder and 47 (75%) an ileal conduit. The mean operative time decreased 60minutes between G1-G3 (P=0.001). No conversions to open approach or intraoperative complications were reported. There were no differences between groups regarding positive margin rates (P=0.6) or the number of lymph nodes removed (P=0.061). The postoperative complication rate was 77% and did not change during the LC (P=0.49). Uretero-enteric stricture rate decreased from 25% in G1 to 9% in G3 (P=0.217). CONCLUSIONS: The inclusion of júnior surgeons to a RARC with ICUD program after the initial 20 cases does not have an impact on the perioperative and pathological outcomes of the procedure. The operative time and the uretero-enteric stricture rate could be reduced during the LC.

Predictive factors of six-week mortality in critically ill patients with SARS-CoV-2: A multicenter prospective study.

OBJECTIVE: The objective of the study is to identify the risk factors associated with mortality at six weeks, especially by analyzing the role of antivirals and munomodulators. DESIGN: Prospective descriptive multicenter cohort study. SETTING: 26 Intensive care units (ICU) from Andalusian region in Spain. PATIENTS OR PARTICIPANTS: Consecutive critically ill patients with confirmed SARS-CoV-2 infection were included from March 8 to May 30. INTERVENTIONS: None. VARIABLES: Variables analyzed were demographic, severity scores and clinical condition. Support therapy, drug and mortality were analyzed. An univariate followed by multivariate Cox regression with propensity score analysis was applied. RESULTS: 495 patients were enrolled, but 73 of them were excluded for incomplete data. Thus, 422 patients were included in the final analysis. Median age was 63 years and 305 (72.3%) were men. ICU mortality: 144/422 34%; 14 days mortality: 81/422 (19.2%); 28 days mortality: 121/422 (28.7%); 6-week mortality 152/422 36.5%. By multivariable Cox proportional analysis, factors independently associated with 42-day mortality were age, APACHE II score, SOFA score at ICU admission >6, Lactate dehydrogenase at ICU admission >470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission <6.5%, and thrombocytopenia whereas the use of lopinavir/ritonavir was a protective factor. CONCLUSION: Age, APACHE II, SOFA>value of 6 points, along with vasopressor requirements or renal replacement therapy have been identified as predictor factors of mortality at six weeks. Administration of corticosteroids showed no benefits in mortality, as did treatment with tocilizumab. Lopinavir/ritonavir administration is identified as a protective factor.

Evaluation of femtosecond laser-assisted cataract surgery after 10 years of clinical application. / Evaluación de la cirugía de la catarata asistida con láser femtosegundo tras 10 años de aplicación clínica.

INTRODUCTION: Femtosecond laser-assisted cataract surgery (FLACS) has been considered a technological advance in modern cataract surgery. After years of experience, it has been observed that clinical outcomes had more complications than expected at the beginning. The aim of this study is to compare the benefits and disadvantages of the FLACS technique with conventional cataract surgery. METHOD: The PubMed and Web of Science platforms were used to search for scientific literature. RESULTS: The FLACS has currently improved the surgical technique in terms of the shorter ultrasound time used and the lower loss of endothelial cells. Likewise, the centration of capsulotomy and the correction of astigmatism with arcuate incisions have also been improved. As disadvantages, are the high cost of the laser, the intraoperative capsular complications, the induction of intraoperative myosis, and the learning curve of the technique. CONCLUSIONS: The FLACS technique is considered beneficial for specific cases, such as patients with scheduled premium surgery, or with low endothelial cell count. However, it is believed that given the technological cost it is not a cost effective technique for most standard cases in our daily clinical practice.

Comparison of perioperative outcomes and complications of robot assisted radical cystectomy with extracorporeal vs intracorporeal urinary diversion. / Comparación de los resultados perioperatorios de la cistectomía radical asistida por robot con derivación urinaria extracorpórea vs. intracorpórea.

OBJECTIVES: To compare perioperative outcomes and complications of robot assisted radical cystectomy (RARC) with extracorporeal (ECUD) vs. intracorporeal urinary diversion (ICUD) for bladder cancer. MATERIAL AND METHODS: Retrospective revision of 43 patients who underwent RARC for bladder cancer between 2015-2018 with at least 3 months of follow-up. The analysis included the initial series of RARC performed by one surgeon with extensive experience in open radical cystectomy. RESULTS: Forty-three patients, 40 men (93%) and 3 women (7%), with a median age of 65 years (44-83) and mean follow-up of 27.7 months (±20.1) underwent RARC. A ECUD was performed in 22 cases (51%), of whom 10 were ileal conduits (45.5%) and 12 neobladders (54.5), and ICUD in 21 cases (49%), of whom 14 were ileal conduits (66.7%) and 7 neobladders (33.3%). Clinical and preoperative characteristics were similar in both groups. The median operative time was 360 minutes (240-540) and length of hospital stay was 12 days (7-73). Thirty-five patients (81%) had postoperative complications, of whom 10 (23%) were major. Operative time, peroperative complications, pathological stage, positive margins, and number of lymph nodes removed did not significantly differ among groups. Patients who underwent ECUD had a higher rate of uretero-ileal strictures than those with ICUD (45.5% vs. 14.3%, P=.026). Among the neobladders, the ECUD developed a higher rate of urethro-neobladder stricture than the ICUD (33% vs. 0%, P=.044). CONCLUSIONS: RARC with ICUD achieved peroperative outcomes and complication rates comparable than those with ECUD. The ICUD could reduce the risk of developing uretero-ileal and urethro-neobladder strictures.

[Autoimmune pancreatitis. Related to a case]. / Pancreatitis autoinmune. A propósito de un caso.

Autoimmune pancreatitis is an entity that has recently been included in the differential diagnosis of chronic pancreatitis-pancreatic mass. The presence of diffuse, irregular Wirsung's duct stenosis, together with high levels of IgG4, the existence of certain autoantibodies and lymphoplasmacytic infiltration of the pancreas are key factors in the diagnosis. An early diagnostic suspicion and multidisciplinary collaboration are vital in these cases to avoid unnecessary surgery as the differential diagnosis is established with such entities as pancreas cancer, chronic pancreatitis, primary biliary cirrhosis or primary sclerosing cholangitis. Autoimmune pancreatitis has an excellent response to steroid therapy, with complete resolution of clinical, analytical and radiological parameters, as occurred in our patient. The very few cases reported so far suggest the need for the elaboration of long-term follow-up studies to determine the prognosis and frequency of its association with other diseases.

Expression of the N-methyl-D-aspartate receptor NR1 splice variants and NR2 subunit subtypes in the rat colon.

N-methyl-D-aspartate (NMDA) receptors and the expression of their different splice variants and subunits were previously characterized in the brain and spinal cord. However, knowledge on the NMDA receptor expression and function in the enteric nervous system is limited. Previous work suggested that NMDA receptors were involved in a rat model of visceral hypersensitivity. The aim of this study was to characterize the expression of the NMDA receptor NR1 splice variants and the NR2 subunit subtypes in the rat colon. We visualized the expression of NR1 protein in the rat submucosal and myenteric plexuses. The NR1 splice variants found in the colon of rats lacked the N1 and C1 cassettes and contained the C2 and C2' cassettes (NR1(000) and NR1(001)). The NR2B and NR2D subunits were also found in the rat colon. Moreover, NMDA receptors in the rat colon were heteromeric, since NR1 was co-localized with NR2B and NR2D subunits using fluorescent immunohistochemistry. The identification of the NMDA receptors in the enteric nervous system could lead to the development of drugs that selectively modulate bowel function.

[Urgent retinal detachment management by the National Health System of Spain. Project Retina 2]. / Manejo de los desprendimientos de retina regmatógenos urgentes en el Sistema Nacional de Salud de España. Proyecto Retina 2.

OBJECTIVE: To identify problems in the urgent management of retinal detachments (RD) in hospitals of the Spanish National Health System (NHS). METHODS: A questionnaire was submitted confidentially to the heads of Ophthalmic Departments of 217 hospitals of the NHS to obtain information on the management of urgent RD during the last year. Data was stored in a Microsoft Access database and statistically analyzed by Excel and Statgraphics. Qualitative variables were analyzed by Chi-Square and Fisher exact tests and quantitative variables by the Kruskall-Wallis test. RESULTS: A global response rate of 54.8% was achieved with higher participation of the Teaching Hospitals (TH). District Hospital and non-Teaching Hospital responses were similar and grouped as non-TH. Eighteen percent of centers, mostly non-TH, had no ophthalmologist on duty. Thirty-six percent had a vitreoretinal specialist on call. Eighty percent of centres admitted to have problems handling urgent RD during weekends. Twenty-four had no ophthalmic surgical theatre available. Fifty percent referred to have problems having an anaesthesiologist available and only 22% had ophthalmic trained personnel (nurses) available. Sixty-four percent of centres performed pars plana vitrectomy (PPV) and 77% of those were able to perform an urgent PPV. Ninety percent admitted that a patient with a macula-threatening RD occurring at the beginning of the week-end would not be treated until at least 24 hours had elapsed, although 84% considered this to be inadequate. CONCLUSION: Despite the methodological problems and bias of this questionnaire, we did identify several important problems in the management of urgent RD by NHS hospitals. The data obtained provides useful information to enable the quality of the NHS care of RD to be improved, particularly that available at the week-end.

[Consensus meeting on selective biopsy of the sentinel node in breast cancer. Spanish Society of Senology and Breast Disease]. / Reunión de Consenso sobre la biopsia selectiva del ganglio centinela en el cáncer de mama. Sociedad Española de Senología y Patología Mamaria.

Selective biopsy of the sentinel node is a useful diagnostic technique in the management of breast cancer that has been introduced into the clinical practice and is widely used and accepted. Based on its results, adequate staging can be made with less associated morbidity. However, at present, there are many methodological variations in how it is done that are pending to be answered in on-going trials and investigations. This involves making Consensus Meetings to try to homogenize the aspects related with the method and indication of the technique. The conclusions of the Consensus Meeting held in Murcia and organized by The Spanish Society of Senology and Breast Disease are expressed in this document.

Unilateral persistent fetal vasculature coexisting with anterior segment dysgenesia. / Vasculatura fetal persistente unilateral asociada a disgenesia del segmento anterior.

CASE REPORT: A case is presented of a 4 week-old female neonate with Peters anomaly (PA) and unilateral persistent foetal vasculature (PFV) referred to our centre due to esotropia. At 12 weeks of age, a penetrating keratoplasty and vitrectomy were performed without major complications in the immediate post-operative period. The patient is currently under an intensive treatment for amblyopia and secondary glaucoma. DISCUSSION: Surgical treatment of PFV is controversial, with prevention of amblyopia, phthisis, and glaucoma being the main reasons for it. Patients with unilateral PFV and type II PA could be good candidates for this combined surgical procedure.

Análisis del impacto de la curva de aprendizaje de la cistectomía radical asistida por robot con derivación urinaria intracorpórea sobre los resultados perioperatorios / Evaluating the impact of the learning curve on the perioperative outcomes of robot-assisted radical cystectomy with intracorporeal urinary diversion

Introducción La cistectomía radical asistida por robot (CRAR) con derivación urinaria intracorpórea (DUIC) es un procedimiento técnicamente complejo. Nuestro objetivo fue analizar el impacto de la curva de aprendizaje (CA) de la CRAR con DUIC sobre los resultados perioperatorios y patológicos.Material y métodos Estudio retrospectivo de 62 pacientes consecutivos intervenidos mediante CRAR con DUIC por tumor vesical entre 2015 y 2020. Se compararon 3 grupos consecutivos de 20 (G1), 20 (G2) y 22 (G3) pacientes para analizar el impacto de la CA. Los casos de G1 fueron intervenidos por un cirujano sénior con experiencia en cirugía robótica y los de G2-G3 por 2cirujanos júnior sin experiencia, pero tutorizados por el sénior.Resultados Los 3grupos tenían características clínico-patológicas similares. A 15 pacientes (24%) se les realizó una neovejiga y a 47 (75%) un conducto ileal. El tiempo medio operatorio descendió 60 min entre G1 y G3 (p=0,001). Ningún paciente precisó conversión a cirugía abierta ni tuvo complicaciones intraoperatorias. No se objetivaron diferencias en la tasa de márgenes positivos (p=0,6) ni en el número de ganglios extraídos (p=0,061) entre los grupos. La tasa de complicaciones postoperatorias fue del 77% y no varió durante la CA (p=0,49). Se objetivó una tendencia en la reducción de tasa de estenosis ureteroileal del 25% en G1 al 9% en G3 (p=0,217).Conclusiones La incorporación de cirujanos júnior a un programa de CRAR con DUIC a partir de los 20 primeros casos no compromete los resultados perioperatorios ni patológicos. Durante la CA se podría reducir el tiempo operatorio y la tasa de estenosis ureteroileal (AU)

Introduction Robot-assisted radical cystectomy (RARC) with intracorporeal urinary diversion (ICUD) is a technically difficult procedure. Our aim was to evaluate the potential impact of the learning curve (LC) on perioperative and pathological outcomes of RARC with ICUD.Material and methods Retrospective study of 62 consecutive patients who underwent RARC with ICUD for bladder cancer between 2015-2020. We compared 3 consecutive groups of 20 (G1), 20 (G2), and 22 (G3) patients to analyze the impact of the LC. G1 cases were performed by a senior surgeon experienced in robotic surgery, while G2-G3 were performed by 2 junior surgeons without experience under the mentorship of the senior surgeon.Results The 3 groups had similar clinical and pathological characteristics. A total of 15 patients (24%) received a neobladder and 47 (75%) an ileal conduit. The mean operative time decreased 60minutes between G1-G3 (P=0.001). No conversions to open approach or intraoperative complications were reported. There were no differences between groups regarding positive margin rates (P=0.6) or the number of lymph nodes removed (P=0.061). The postoperative complication rate was 77% and did not change during the LC (P=0.49). Uretero-enteric stricture rate decreased from 25% in G1 to 9% in G3 (P=0.217).Conclusions The inclusion of júnior surgeons to a RARC with ICUD program after the initial 20 cases does not have an impact on the perioperative and pathological outcomes of the procedure. The operative time and the uretero-enteric stricture rate could be reduced during the LC (AU)

[National survey on vitreo-retinal surgery and the management of rhegmatogenous retinal detachments in Spain. Project retina 2]. / Encuesta nacional sobre la cirugía vítreo-retiniana y la atención de los desprendimientos de retina regmatógenos en España. Proyecto retina 2.

PURPOSE: To obtain information throughout Spain on the current management of vitreo-retinal surgical diseases, the number of ophthalmologists involved in retinal surgical diseases care, and the urgent management of retinal detachments. METHODS: A 30 item questionnaire was sent by mail, on two separate occasions, to the heads of Ophthalmology Departments of 276 centers in Spain. RESULTS: A total response rate of 48.2% was achieved, however the answers from private centers represented only 9.4% of the total so these were excluded from the analysis. The centers most likely to respond were those in Teaching Hospitals (TH) (52.3%). Of these, 64% of hospitals responded that, in the last year, they performed pars plana vitrectomies (PPV) and 70% performed more than 100 PPVs in the year. In all, 77% of the centers that performed PPVs had also performed them urgently. A total of 75% of hospitals indicated that they had ophthalmologists mainly dedicated to retinal diseases care, with a median of 2 specialists per center, with this representing 23% of their total staff. Retinal surgery was performed by general ophthalmologists in 11.5% of centres. Only 40.3% of hospitals audit their results (37.5% TH). CONCLUSIONS: Despite the existence of a relatively low response rate, as well as some biases and methodological problems, data on the management of retinal surgical disease has been obtained for the first time at a national level. This data will facilitate later studies and must be taken into consideration in improving the planning and adequate management of these diseases in Spain.

Speed-up hyperspheres homotopic path tracking algorithm for PWL circuits simulations.

In the present work, we introduce an improved version of the hyperspheres path tracking method adapted for piecewise linear (PWL) circuits. This enhanced version takes advantage of the PWL characteristics from the homotopic curve, achieving faster path tracking and improving the performance of the homotopy continuation method (HCM). Faster computing time allows the study of complex circuits with higher complexity; the proposed method also decrease, significantly, the probability of having a diverging problem when using the Newton-Raphson method because it is applied just twice per linear region on the homotopic path. Equilibrium equations of the studied circuits are obtained applying the modified nodal analysis; this method allows to propose an algorithm for nonlinear circuit analysis. Besides, a starting point criteria is proposed to obtain better performance of the HCM and a technique for avoiding the reversion phenomenon is also proposed. To prove the efficiency of the path tracking method, several cases study with bipolar (BJT) and CMOS transistors are provided. Simulation results show that the proposed approach can be up to twelve times faster than the original path tracking method and also helps to avoid several reversion cases that appears when original hyperspheres path tracking scheme was employed.