Sonication of catheter tips for improved detection of microorganisms on external ventricular drains and ventriculo-peritoneal shunts.

The diagnosis of infections involving internal or external neurosurgical drainage devices is challenging, and to our knowledge no single reliable microbiological test exists. We used sonication to study bacterial colonization in 14 explanted external ventricular drains (EVD) and 13 ventriculo-peritoneal shunt (VPS) devices. This technique dislodges biofilm bacteria from the surface of implanted materials before culture. Removed devices were sonicated in saline (40 kHz, 1 minute, 0.25 W/cm(2)), the resulting fluid was cultured aerobically and anaerobically at 37°C, and bacterial growth was counted. Ventricular cerebrospinal fluid (CSF) was cultured separately. In the EVD group, sonication cultures grew significantly more bacteria (64%, 9/14) than cultures of aspirated ventricular CSF (14%, 2/14). In the VPS group the difference was not significant. Positive sonication cultures of EVD catheters yielded a median of >100 colony forming units (CFU) (range, 60-800). For positive sonication cultures of VPS, the median was 1000 CFU (range, 20-100,000). All patients with bacteria in their CSF also had positive sonication cultures from the removed device. Of the five patients with sterile or presumably contaminated CSF cultures but positive sonication cultures of removed shunts, one became afebrile after removal of the EVD, two developed meningitis and two remained asymptomatic. Sonication culture of EVD appears to improve the microbiological assessment of device-related infection and it corroborates with CSF cultures of revision surgery for VPS. Sonication of the removed EVD tip may raise awareness for the onset of meningitis.

Intrapericardial pacemaker in a 2-kilogram newborn.

A 2-kilogram child had a pacemaker implanted by a subxyphoid approach with the generator located under the rectus sheath. Days later, the battery eroded the abdominal wall and the peritoneum. The whole system was removed and a new one was implanted inside the pericardium on an emergent basis.

Fracturas femorales periprotésicas de rodilla tratadas con clavo intramedular retrógrado y osteosíntesis con placa: comparación de resultados a medio-largo plazo

INTRODUCTION: The femoral periprosthetic fracture of the knee is one of the most feared complications because of its repercussions. Incidence are more and more likely due to the increase of total implanted arthroplasty of the knee, due to the increasing lifespan among the general population. The objective of this study is to analyze some of the perioperative aspects of the treatment of these fractures, comparing the use of osteosynthesis with plates and the retrograde nailing in those patients with femoral periprosthetic knee fractures with a stable implant. MATERIAL AND METODS: The study retrospectively examines 18 cases treated consecutively in our hospital (3 men and 15 women, average age of 72.7 years) between the years of 2000 and 2009. All fractures were located in the distal femur and on a stable implant. Eight were treated through retrograde nailing (Group I) and ten with plates (Group II). The cases are analyzed through the tests of the University of Mann-Withney and the exact Fischer test, with significant values of p≤0.05, the variables of median hospital stay, necessity of transfusion indicated with values of hemoglobin less than 8 mg/ml, preoperative radiological alignment and postoperative alignment of the total knee prosthesis (TKR), measured following the anatomical tibiofemoral axis, time of consolidation and incidence of localized complications in both groups. RESULTS: We did not find any statistically significant differences between the two groups in any of the variables analyzed. Localized complications are more frequent in Group I (62.5 percent of patients) than in Group II (10 percent of patients). The need for transfusion is greater in Group II (40 percent) than in Group I (12.5 percent). CONCLUSIONS: The type of implant used in treatment of femoral periprosthetic knee fracture does not significantly influence perioperative factors. The treatment for this type of fractures should be individually chosen in relation to the type of fracture, characteristics of the patient and stability and prosthesis model of the primary knee.

El Papel del Bibliotecario Integrado en las Comisiones Clínicas, Docencia Postgraduada e Investigación en el Área Sanitaria Este de Málaga-Axarquía (ASEMA)

The concept of Library of the Health Sciences has noticeably changed during the last decade. The embedded librarian is a recently emerged figure, who works as a member of multidisciplinary groups with the mission of providing them with relevant literature as well as media for acquisition, exchange and dissemination of information. This figure has been gradually implanted in some committees of the ASEMA. The objective of the present work is to describe the functions of the embedded librarian and its results in our area.

Spinal cord stimulation treatment for angina pectoris: more than a placebo?

BACKGROUND: The effects of thoracolumbal spinal cord stimulation (SCS) are confined to restricted microcirculatory areas. This limitation is generally attributed to a predominantly segmental mode of action on the autonomic nervous system. The goal of this study was to determine whether SCS applied close to supraspinal autonomic centers would induce generalized hemodynamic changes that could explain its alleged antianginal properties. METHODS: Invasive hemodynamic tests were performed in 15 anesthetized Göttingen minipigs submitted to iterative cervical SCS of various duration and intensity. RESULTS: Hemodynamic changes exceeding 10% were observed in 59 of 68 SCS sessions (87%). Their extent and time to peak varied with SCS intensity. At 2, 5, and 10 V, significant (t test p < 0.05) peak changes occurred in cardiac output (+34%, +29%, and +28%, respectively), stroke volume (+19%, +16%, +15%), mean pressure (+9%, +27%, +40%), heart rate (+14%, +23%, +14%), systemic (-17%, NS, NS), and pulmonary vascular (25%, NS, NS) resistances. Strikingly, at 2 V, the increase in cardiac output (+34%) was higher than the synchronous rise in rate pressure product (+22%), indicating efficient cardiac work. At 10 V, however, the cardiac work was inefficient (rate pressure product + 53%/cardiac output + 28%). CONCLUSIONS: Low-voltage cervical neuromodulation reduces the postcharge and improves cardiac work efficiency. The resulting reduction in oxygen myocardial demand may account for decreased anginal pain.

Evaluation of the antitumoral effect sunitinib eluting beads in VX2 liver tumour in a rabbit model.

Background: We demonstrated that DC Bead (Biocompatibles UK, Ltd) could be loaded with sunitinib and injected intra-arterially in the rabbit without unexpected toxicity. The purpose of this study is to evaluate the antitumoral effect of sunitinib eluting beads in the VX2 tumor model of liver cancer. Methods: VX2 tumors were implanted in the left liver lobe of New-Zealand white rabbits. Animals were assigned to 3 groups: Group 1 (n=6) received 1.5mg of sunitinib loaded in 0.05ml of 100-300um DC Bead, group 2 (n=5) received 0.05ml of 100-300um DC Bead, group 3 (n=5) received 0.05ml NaCl 0.9% in the left hepatic artery. One animal in each group was sacrificed at 24 hours and the others were followed for survival until day 15. Liver enzymes were measured daily. In group 1, plasmatic sunitinib concentration were measured daily by LC MS/MS tandem mass spectroscopy. At day 15 all living animals were sacrificed. After sacrifice, the livers were harvested for determination of the VEGF receptor tyrosine kinase activity by western blot and histopathological examination. Results: In group 1, no animals died during follow-up. In group 2, 2 animals died during follow-up on day x. In control group 3, 3 animals died during follow up on day x. In group 1 plasmatic sunitinib levels remained under therapeutic concentration throughout the experiment. Very high concentrations of sunitinib were measured in the liver tissue 24 and 15 days after embolization. Inhibition of the phosphorylation of the RTK was demonstrated at 24h and 15 days in groups 1. Sunitinib eluting beads seemed to penetrate in the tumor more effectively and there was more necrosis around the beads than their bland counterparts. Conclusions: Administration of sunitinib eluting beads in VX2 carrying rabbits resulted invery high drug concentrations at the site of embolization with minimal systemic passage. Despite the very high tissular sunitinib concentration we did not observe any additional toxicity with loaded beads. Sunitinib eluting beads inhibit the activation of RTK's triggered by ischemia and seem to prolong survival of the treated animals. Therefore we consider that local treatment with sunitinib may provide a promising approach for the treatment of liver cancer.

Efectividad comparativa del seguimiento remoto a personas con marcapasos cardíacos frente al convencional: calidad de vida a los 6 meses.

BACKGROUND The use of remote follow-up (RF) of people with pacemakers (PM) is limited in comparison to the hospital modality (HS), being still poor the scientific evidence that shows their comparative effectiveness. The aim of this study was to compare the quality of life in individuals with different modalities of follow-up. METHODS Controlled, not randomized nor masked clinical trial, with data collection at pre and post-implantation of pacemakers during the 6 months follow-up. All patients over 18 years-old who were implanted a PM during the study period were selected (n = 83), and they were assigned to RF (n = 30) or HF (n = 53) groups according to their personal characteristics and patient's preferences. Baseline characteristics and number of visits to the hospital were analysed, the EuroQol-5D (EQ5D) questionnaire was administered to evaluate the health-related quality of life, and Duke Activity Status Index (DASI) to assess the functional capacity. RESULTS There were no significant differences between both groups in relation to the baseline analysis, EQ5D (RF:0.7299; HF:0.6769) and DASI (RF:21.41; HF:19.99). At 6 months the quality of life was improved in both groups (EQ5D RF:0.8613; HF:0.8175; p = 0,439) still without significant differences between them. DASI score was similar to baseline (20.51 vs 21.80). RF group performed less transmissions/visits per patient (1.57) than hospital group (1.96; relative reduction 31%; p = 0.015). CONCLUSIONS Remote follow-up of people with pacemakers might be considered as an equivalent option to the hospital follow-up in relation to the quality of life and it reduces the number of hospital visits.

Experience and intermediate-term results using the Contegra heterograft for right ventricular outflow reconstruction in adults.

OBJECTIVES: The Contegra bioprosthesis (valved heterologous bovine jugular vein) is used for reconstruction of the right ventricular outflow tract (RVOT) in congenital heart malformations and pulmonary valve replacement in different settings. Compared to pulmonary homografts, the Contegra conduit is readily available 'on the shelf'. So far, its use was mainly described in children. The aim of this study is to evaluate the feasibility and the outcome of Contegra graft implantation in the adult. METHODS: Between November 1999 and December 2007, a total of 32 Contegra grafts were implanted in 31 patients (24 men and 7 women), with a mean age of 35.7+/-10.5 years (range 18-54 years). All operations have been completed through median sternotomy with cardiopulmonary bypass. Indications included: Ross procedure for aortic valve disease (n=22); re-operation of corrected Fallot-tetralogy (n=5); isolated pulmonary valve disease (n=2); re-operation of double outlet right ventricle (DORV) (n=1); pulmonary stenosis in congenital dilated cardiomyopathy (DCM) (n=1). Conduit sizes included 22 mm (n=31), 20 mm (n=1). RESULTS: There was no hospital mortality and no valved conduit related early morbidity. In the median follow-up of 38 months (range 1-99 months) of 28 patients there was one late death, not conduit related (total mortality 3.6%). Re-operation for symptomatic graft stenosis was realised in two patients, 7 and 16 months after primo-implantation, corresponding to graft related late morbidity of 7.1%. CONCLUSIONS: In this small review of 32 operations using the Contegra graft for RVOT reconstruction in adult cardiac surgery for different indications, we observed good postoperative mid-term results concerning conduit function. Mean transpulmonary pressure gradients remain low (13.3+/-6.6 mmHg postoperative, 14.5+/-7.9 mmHg at follow-up). The use of the Contegra graft seems to be a good alternative to the homograft with low operative mortality and morbidity. Long-term outcome data are not available and further investigations must be performed to evaluate results.

Activities of daily living with reverse prostheses: importance of scapular compensation for functional mobility of the shoulder.

HYPOTHESIS: The nonanatomical design of reverse shoulder prostheses induce medial displacement of the center of rotation, impingements and may reduce the mobility of the shoulder. The aim of this study is to test the hypothesis that during activities of daily living functional mobility of the shoulder can be restored by scapular compensation. MATERIAL AND METHODS: A numerical 3-dimensional model was developed to reproduce the movement of the scapula and humerus, during 4 activities of daily living measured experimentally. This hypothesis was tested in 4 configurations of the aequalis reverse prosthesis (standard 36-mm glenosphere, 42-mm glenosphere, lateralized 36-mm glenosphere, lateralized Bony Increased-Offset Reverse Shoulder Arthroplasty [BIO-RSA]), which were implanted in the virtual model. All impingement positions were evaluated, as the required scapular compensation to avoid impingements. RESULTS: With the 36-mm glenosphere, impingements occurred only for rest of hand to back-pocket positions. The 42-mm partly improved the mobility. The 2 lateralized glenospheres were free of impingement. When impingements occurred, the scapular compensation was less than 10°. CONCLUSION: Most reverse prostheses impingements reported in clinical and biomechanical studies can be avoided, either by scapular compensation or by a glenosphere lateralization. After reverse shoulder arthroplasty, a fraction of the mobility of the gleno-humeral is transferred to the scapulo-thoracic joint.

Une insuffisance cardiaque traitée par glucocorticoïdes [A heart insufficiency treated by glucocorticoids]

Arrhythmogenic right ventricular dysplasia was diagnosed in 2000 in this 44-year-old male patient with a history of syncope. An internal defibrillator was implanted. Six years later the patient was readmitted with severe heart failure, and cardiac sarcoidosis was diagnosed by myocardial biopsy. Response to a course of glucorticoids was favourable. We herein review diagnostic strategies and therapeutic options in this rare disorder.

Acute inflammatory reaction associated with endoluminal bypass grafts.

PURPOSE: Nonspecific inflammatory reactions characterized by local tenderness, fever, and flu-like discomfort have been seen in patients undergoing endoluminal graft placement in the abdominal aorta or the femoral arteries. We undertook a study to assess the clinical and laboratory parameters of this inflammation. METHODS: Ten patients with femoropopliteal artery (n = 9) or aortic (n = 1) lesions were treated with EndoPro System 1 stent-grafts made of nitinol alloy and covered with a polyester (Dacron) fabric. Eleven patients implanted with a bare nitinol stent served as the control group. RESULTS: In the stent-graft group, four patients showed clinical signs of acute inflammation manifested by fever and local tenderness. Three of these patients suffered thrombosis of the stent-grafts during the first month of follow-up. Plasma levels of interleukin-1 beta and interleukin-6 in all stent-graft patients were markedly increased 1 day after intervention (7.3 +/- 2.8 versus 90.2 +/- 34.1 pg/mL and 15.6 +/- 5.8 versus 175.5 +/- 66.3 pg/mL, respectively; p < 0.01). This was followed by an increase in fibrinogen (3.0 +/- 0.2 versus 5.0 +/- 0.2 g/L; p < 0.05) and C-reactive protein (14.6 +/- 3.3 versus 77.5 +/- 15.0 mg/L; p < 0.01) at 1 week. No direct correlation between the inflammatory markers and symptoms could be found. In vitro analysis showed that individual components of the stent-graft did not activate human neutrophils, whereas the intact stent-graft itself induced a marked neutrophil activation. CONCLUSIONS: The component of the self-expanding stent-graft responsible for the nonspecific inflammatory reaction was not identified in this study. It is likely that the stent-graft itself or some as yet unrecognized element of the device other than the Dacron fabric or metal alloy may be a potent in vivo inducer of cytokine reaction by neutrophils.

Decoding sequence learning from single-trial intracranial EEG in humans.

We propose and validate a multivariate classification algorithm for characterizing changes in human intracranial electroencephalographic data (iEEG) after learning motor sequences. The algorithm is based on a Hidden Markov Model (HMM) that captures spatio-temporal properties of the iEEG at the level of single trials. Continuous intracranial iEEG was acquired during two sessions (one before and one after a night of sleep) in two patients with depth electrodes implanted in several brain areas. They performed a visuomotor sequence (serial reaction time task, SRTT) using the fingers of their non-dominant hand. Our results show that the decoding algorithm correctly classified single iEEG trials from the trained sequence as belonging to either the initial training phase (day 1, before sleep) or a later consolidated phase (day 2, after sleep), whereas it failed to do so for trials belonging to a control condition (pseudo-random sequence). Accurate single-trial classification was achieved by taking advantage of the distributed pattern of neural activity. However, across all the contacts the hippocampus contributed most significantly to the classification accuracy for both patients, and one fronto-striatal contact for one patient. Together, these human intracranial findings demonstrate that a multivariate decoding approach can detect learning-related changes at the level of single-trial iEEG. Because it allows an unbiased identification of brain sites contributing to a behavioral effect (or experimental condition) at the level of single subject, this approach could be usefully applied to assess the neural correlates of other complex cognitive functions in patients implanted with multiple electrodes.

Intermittent atrial tachycardia promotes repolarization alternans and conduction slowing during rapid rates, and increases susceptibility to atrial fibrillation in a free-behaving sheep model.

INTRODUCTION: Paroxysmal atrial fibrillation (AF) may be triggered by intermittent atrial tachycardia, and ultimately lead to persistent AF. However, the mechanisms by which intermittent atrial tachycardia promotes sustained AF are not well understood. METHODS AND RESULTS: Eight sheep were chronically implanted with 2 pacemakers for the recording of broadband right atrial unipolar electrograms, and for the delivery of electrophysiological stimulation protocols and intermittent right atrial tachycardia. Right atrial kinetics of activation recovery interval (ARI) as a surrogate for action potential duration, of conduction time and velocity, and of repolarization alternans were analyzed at incremental pacing rates during the remodeling process induced by weeks of intermittent atrial tachycardia until the development of sustained AF. Intermittent atrial tachycardia decreased ARI and blunted its rate adaptation, facilitated atrial capture, and slowed conduction at high rates, and increased susceptibility to pacing-induced AF. In spite of blunted ARI rate adaptation, right atrial repolarization alternans was maintained during remodeling, and further increased in magnitude just before rapid pacing-induced AF. CONCLUSION: This study suggests that weeks of intermittent right atrial tachycardia result in a gradual electrical remodeling favorable for wavebreaks and reentry that may facilitate fibrillation.

Análisis y diseño de antenas dipolo y parche para aplicaciones implantadas en el cuerpo humano

En els darrers anys, els sistemes de telemetria per a aplicacions mèdiques han crescut significativament en el diagnòstic i en la monitorització de, per exemple, la glucosa, la pressió de la sang, la temperatura, el ritme cardíac... Els dispositius implantats amplien les aplicacions en medicina i incorpora una millora de qualitat de vida per a l’usuari. Per aquest motiu, en aquest projecte s’estudien dues de les antenes més comuns, com son l’antena dipol i el patch, aquesta última és especialment utilitzada en aplicacions implantades. En l’anàlisi d’aquestes antenes s’han parametritzat característiques relacionades amb l’entorn de l’aplicació, així com també de la pròpia antena, explicant el comportament que, a diferencia amb l’espai lliure, les antenes presenten a canvis d’aquests paràmetres. Al mateix temps, s’ha implementat una configuració per a la mesura d’antenes implantades basat en el model del cos humà d’una capa. Comparant amb els resultats de les simulacions realitzades mitjançant el software FEKO, s’ha obtingut gran correspondència en la mesura empírica d’adaptació i de guany de les antenes microstrip. Gràcies a l’anàlisi paramètric, aquest projecte també presenta diversos dissenys de les antenes optimitzant el guany realitzable amb l’objectiu d’aconseguir la millor comunicació possible amb el dispositiu extern o estació base.

Antibiotic cement nail for the treatment of posttraumatic intramedullary infections of the tibia: Midterm results in 10 cases.

INTRODUCTION: This is a single, level 1 trauma centre, prospective consecutive patient series with intramedullary infection in the presence of unstable tibial fracture treated using the Kirschner wire-reinforced, antibiotic cement nail. PATIENTS AND METHODS: A total of 10 consecutive patients (eight males and two females) with a mean age of 42 years (range, 20-59) suffering from infection after intramedullary nailing for tibial fracture, admitted during a period of 4 years, were included. An antibiotic cement-coated nail, handmade at the time of surgery, was implanted in all patients. This was followed by a standardised 6-week treatment protocol, extraction of the nail and definitive fixation. RESULTS: At 6 years of follow-up, infection eradication and bony union were possible in all of the patients. No further infection treatment was necessary; however, all of our patients underwent additional procedures (mean: four additional procedures per patient) for cosmetic or other non-infectious reasons (bone grafting, muscle flaps, etc.). CONCLUSIONS: The antibiotic cement-coated nail seems to be an effective treatment for intramedullary infections of the fractured tibia.