Reducing g(2)(0) of a parametric down-conversion source via photon-number resolution with superconducting nanowire detectors.

Multiphoton contributions pose a significant challenge for the realisation of heralded single-photon sources (HSPS) based on nonlinear processes. In this work, we improve the quality of single photons generated in this way by harnessing the photon-number resolving (PNR) capabilities of commercial superconducting nanowire single-photon detectors (SNSPDs). We report a 13 ± 0.4% reduction of g(2)(τ = 0), even with a collection efficiency in the photon source of only 29.6%. Our work demonstrates the first application of the PNR capabilities of SNSPDs and shows improvement in the quality of an HSPS with widely available technology.

Single-shot discrimination of coherent states beyond the standard quantum limit.

The discrimination of coherent states is a key task in optical communication and quantum key distribution protocols. In this work, we use a photon-number-resolving detector, the transition-edge sensor, to discriminate binary-phase-shifted coherent states at a telecom wavelength. Owing to its dynamic range and high efficiency, we achieve a bit error probability that unconditionally exceeds the standard quantum limit (SQL) by up to 7.7 dB. The improvement to the SQL persists for signals containing up to approximately seven photons on average and is achieved in a single shot (i.e., without measurement feedback), thus making our approach compatible with larger bandwidths.

The Bolton Treovance abdominal stent-graft: European clinical trial design.

Endovascular aortic repair (EVAR) has emerged as a promising, less invasive alternative to conventional open surgery for the treatment of infrarenal abdominal aortic aneurysms (AAAs). In the last 20 years, the application rate of EVAR and its clinical results have significantly improved thanks to the evolution of stent-grafts and endovascular delivery systems. However, further development is still needed to reduce the incidence of complications and secondary re-interventions. The Treovance abdominal aortic stent-graft (Bolton Medical, Barcelona, Spain) is a new-generation endovascular device, developed to increase flexibility, lower profile, improve deployment and sealing mechanisms. In particular, it is provided with some innovative features as a double layer of proximal barbs (suprarenal and infrarenal) for supplemental fixation, dull barbs between modules to avoid potential leg disconnections, detachable outer sheath provided with a new-design hemostatic valve, and a double improved mechanism (slow motion and "pin and pull") for precise stent-graft deployment. A European prospective, non-randomized, multi-institutional, "first-in-human" trial (the ADVANCE trial) was conducted from March to December 2011 to assess the safety and performance of the Treovance stent-graft system before commercialization. Thirty patients with anatomically suitable non-ruptured AAAs were enrolled at five clinical sites in Italy, Spain, and Germany. EVAR was completed successfully in all patients. The stent-graft was delivered and deployed safely even in heavily angulated or calcified anatomies. No 30-day device-related complications nor deaths were observed. Preliminary experience with the Treovance abdominal stent-graft within the ADVANCE trial was satisfactory with regard to technical success and perioperative clinical results. Follow-up data are needed to assess mid- and long-term clinical outcomes, along with durability of this new-generation endovascular device.

Síndrome del cascanueces (nutcracker) secundario a vena renal izquierda retroaórtica: tratamiento quirúrgico con transposición de la vena renal / Nutcracker syndrome secondary to retroaortic left renal vein: surgical treatment with transposition of the renal vein

INTRODUCCIÓN: El síndrome del cascanueces renal producido por una vena renal izquierda retro-aórtica (VRIR) es excepcional. Si produce clínica significativa, el tratamiento es quirúrgico (transposición de vena renal) MATERIAL Y MÉTODO: Se presenta un caso clínico y se revisa brevemente la literatura. RESULTADOS: Tras la transposición de la VRIR la paciente evolucionó correctamente. RESUMEN: La cirugía en casos de síndrome del cascanueces por VRIR es una opción útil para controlar la clínica en estas situaciones (AU)

INTRODUCTION: Renal nutcracker syndrome caused by left retro-aortic renal vein (LRRV) is an exceptional condition. In case of significant clinical problems, surgical treatment is required (renal vein transposition). MATERIAL AND METHOD: We report a case of LRRV and literature is reviewed briefly. RESULTS: After the transposition of the LRRV the patient developed properly. SUMMARY: The surgery in cases of nutcracker syndrome by LRRV is useful to control symptoms (AU)

Seguimiento a cinco años de los pacientes ASA IV intervenidos de aneurisma de aorta infrarrenal / Five years follow-up of patients ASA IV operated of infrarenal aortic aneurysm

Objetivos. Uno de los argumentos esgrimidos para justificar la utilización de endoprótesis en pacientes con aneurismas de aorta es que obtengan una clasificación ASA IV en la valoración preoperatoria de riesgo anestésico. Para rechazar o defender este criterio hemos realizado un estudio retrospectivo de este tipo de pacientes intervenidos en el período 1991-1995 con el fin de conocer, de esta forma, su evolución. Pacientes y métodos. Se consideraron ASA IV 36 pacientes de un total de 126 intervenidos entre 1991 y 1995 de aneurisma de aorta infrarrenal. Se excluyeron los pacientes intervenidos urgentemente y los casos de pinzamiento suprarrenal. La edad media fue de 69,6 y sólo uno era del sexo femenino. Los factores de riesgo predominante fueron el tabaquismo y la hipertensión. La enfermedad asociada más frecuente fue la cardiopatía, sobre todo la isquémica, y la limitación crónica al flujo aéreo. Resultados. La mortalidad hospitalaria fue del 2,7 por ciento, la mortalidad al año fue del 8,3 por ciento, a los tres años del 36 por ciento, y a los cinco años, del 55,5 por ciento. La causa más frecuente fue el cáncer, seguido del infarto de miocardio. Conclusiones. La mortalidad operatoria de los ASA IV en nuestra serie es baja, aceptable y similar a la mortalidad global de los aneurismas, entre ellos los ASA III. La clasificación ASA presenta un bajo valor predictivo en cuanto a la mortalidad quirúrgica. Ambas conclusiones se deben a la sobrevaloración del riesgo en alguno de nuestros pacientes y, por lo tanto, la clasificación ASA no es el método adecuado de guía para la inclusión de pacientes en el tratamiento con endoprótesis aórtica; ésta debe basarse en criterios anatómicos y siempre dentro de un estudio controlado. (AU)

Factors increasing the mortality rate for patients with ruptured abdominal aortic aneurysms.

The objective of this report was to analyze the current surgical results of operative treatment in patients suffering ruptured AAA (abdominal aortic aneurysms) and to define those independent predictive factors for mortality. During a period of 2 years, from January 1996 to December 1997, 144 patients operated on for ruptured AAA in 10 hospitals were included in a multicenter retrospective study. Among the collected variables concerning each patient, those with potential relation to surgical mortality were studied: gender, age, diabetes, hypertension, cardiopathy, pulmonary obstructive disease, preoperative renal dysfunction, symptomatic cerebrovascular disease, peripheral vascular disease, hematocrit on admission, preoperative hypotension < 80 mmHg, loss of consciousness, cardiac arrest, aortic aneurysm location (infrarenal versus non-infrarenal), iliac involvement, aneurysm size, type of rupture, left renal vein ligature, ligature of a patent inferior mesenteric artery, place of aortic cross-clamping, type of grafting, exclusion of both hypogastric arteries, venous technical complications, associated surgery, use of cell saver, intraoperative blood loss, and postoperative complications (renal failure, sepsis, coagulopathy, cardiac complications, pulmonary complications, colon ischemia, prosthetic graft complications, and need for reoperation). Those variables with statistical significance in the univariate analysis were introduced into a multivariate logistic regression model to determine the independent predictors of death. From our results we concluded that surgery for ruptured abdominal aortic aneurysms continues to have an excessively high mortality rate. Even though some preoperative variables could be identified as predictors of mortality, an absolute mortality risk has not yet been determined and the decision to negate surgery should be individualized rather than taken on that basis only. Early diagnosis and treatment of symptomatic aneurysms would improve mortality figures and selective screening should be contemplated.

[Aortobifemoral prostheses with "0" porosity. Results after 2 years' experience]. / Prótesis aortobifemorales porosidad "O". Resultados tras dos años de experiencia.

During the last years diverse types of Dacron prosthesis without porosity (because to be impregnated by different materials) have appeared. In the presented study, outcomes from three different types of prosthesis (differentiated by the impregnated material) were evaluated and a comparison with classical prosthesis was made.

[Capillaroscopic observation in angiologic diagnosis]. / "La observación capiloroscópica en el diagnóstico angiológico".

The authors present their experience with Morphologic Capillaroscopy, and analyze the diagnostic dates provided by this technique to the current Angiology and Vascular Surgery protocols. Morphologic anomalies founded during diverse systemic diseases as well as the changes on the capillary field produced in cases of chronic ischaemia and venous insufficiency were analysed. The study was made on the basis of 236 capillaroscopic images and it was completed by an extensive bibliographic review of the subject.

[Non-invasive monitoring of cardiac output with Doppler in aortoiliac surgery. Preliminary study]. / Monitorización incruenta del gasto cardíaco por Doppler en cirugía aorto-ilíaca. Estudio preliminar.

The experience about 18 patients subjected to aortoiliac surgery is exposed. The cardiac flow was bloodless monitorized by means of an apparatus, based in Doppler effect, which proved its accuracy and usefulness. Authors considers necessary to monitorize the cardiac flow in this sort of surgery, and this bloodless method has showed its validity and simplicity.