Impacto de la ablación por radiofrecuencia en el tratamiento de las metástasis hepáticas de cáncer colorrectal

Els avenços científics i tecnològics dels últims anys han proporcionat coneixements sobre les metàstasis hepàtiques del càncer colorrectal que es tradueix en millores dels tractaments i una disminució dels efectes secundaris derivats d'ells. Hem realitzat un estudi comparatiu a partir de la nostra base de dades confeccionada de manera prospectiva amb pacients intervinguts de metàstasis hepàtiques origen colorectal. Es van analitzar els resultats dels pacients en funció del tractament quirúrgic rebut. Un grup estava conformat per pacients amb resecció hepàtica aïllada i l'altre per pacients tractats mitjançant resecció hepàtica associada amb ablació per radiofreqüència.

Manejo de las Lesiones Renales Menores de 4 Centímetros Mediante Ablación por Radiofrecuencia Percutánea

La nefrectomía parcial se ha constituido en el tratamiento de referencia de los tumores renales pequeños. En pacientes de alto riesgo quirúrgico se han planteado técnicas mínimamente invasivas como la ablación por radiofrecuencia como una alternativa terapéutica. En este estudio evaluamos nuestra experiencia en la aplicación de esta técnica en cuanto sus resultados oncológicos y en cuanto a su efecto sobre la función renal a los 3 y 12 meses de seguimiento. Se concluye que se trata de una técnica que no altera la función renal con resultados oncológicos prometedores que deben ser validados por estudios a largo plazo.

Aïllament epicàrdic de les venes pulmonars amb ultrasons d’alta intensitat per al tractament quirúrgic de la fibril•lació auricular no primària

Aquest és un estudi prospectiu observacional de cohorts de 59 malalts amb fibril•lació auricular no primària tractats amb ablació epicàrdica de venes pulmonars amb ultrasons. Els objectius van ser avaluar l’efectivitat de l’ablació, establir les diferències dels resultats entre una fibril•lació auricular paroxística i una crònica i establir les diferències dels resultats segons la patologia cardíaca primària. L’efectivitat de l’ablació per mantenir ritme sinusal a l’any fou del 65,3%. Per la fibril•lació auricular paroxística l’efectivitat al mes fou del 82,4% i del 41,7% per la crònica (p=0,005) i a l’any del 82,4% i del 56,3% respectivament (p=0,068).

Radiofreqüència versus fleboextracció i CHIVA en el tractament d’insuficiència venosa. Assaig clínic aleatoritzat: resultats preliminars

L’ insuficiència venosa crònica fa referència a un conjunt de quadres clínics que venen determinats fisiopatològicament per la hipertensió venosa. La seva elevada prevalença (33% de la població mundial) així com els elevats costos derivats de la mateixa en termes de discapacitat i absentisme laboral fan necessaris estudis per determinar quines son les millors estratègies de tractament. Noves tecnologies mínimament invasives que utilitzen l’ ablació de varius mitjançant accessos percutanis s’ha introduït en el tractament entre les que destaca la tècnica de la radiofreqüència. Aquestes tècniques redueixen la morbiditat postoperatòria i faciliten una ràpida recuperació funcional millorant la satisfacció del pacient en termes de qualitat de vida.

Species resolved analysis of the expansion of hydroxyapatite laser ablation plumes

The plume generated by ablation of hydroxyapatite targets under ArF excimer laser irradiation has been investigated by means of fast intensified CCD-imaging and optical emission spectroscopy. Results have shown that the plume splits into two plasma clouds as it expands. Time and spatial resolved spectra have revealed that under the experiment conditions emission is mostly due to calcium neutral atoms and calcium oxide molecular radicals. Imaging of the plume with the aid of bandpass filters has demonstrated that the emissive species in the larger and faster plasma cloud are calcium neutral atoms, whereas in the smaller and slower one they are calcium oxide molecular radicals

Characterization of hydroxyapatite laser ablation plumes by fast intensified CCD-imaging

ArF excimer laser pulses (193 nm, 20 ns, 150 mJ) have been focused on a hydroxyapatite (HA) target in similar conditions to those normally used for thin film deposition. Fast intensified CCD images of HA laser ablation plumes have been taken in vacuum and under different water vapor pressures ranging from 0.01 mbar to 1 mbar. Images of HA ablation in vacuum have shown a plume freely expanding at a constant velocity of 2.3 106 cm/s. HA ablation under a water vapor pressure of 0.01 mbar has revealed an expansion behavior very similar to that of ablation in vacuum. Images taken under a water vapor pressure of 0.1 mbar have shown the formation of a shock structure in the plume. Finally, HA ablation under a water vapor pressure of 1 mbar has revealed the development of some irregularities in the shape of the plume.

Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

BS-SEM evaluation of the tisular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes

BS-SEM evaluation of the tisular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes

BS-SEM evaluation of the tisular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes