Near-Infrared Photoactive Theragnostic Gold Nanoflowers for Photoacoustic Imaging and Hyperthermia.

Branched anisotropic gold nanostructures present distinguished performance acting both as contrast agents for photoacoustic imaging and as active agents for photothermal therapies. Despite advances in their fabrication methods, the synthesis of such gold nanomaterials in a simple and reproducible way is still a challenge. In this paper, we report the development of branched anisotropic gold nanoparticles, the so-called gold nanoflowers (AuNFs), as near-infrared active theragnostic materials for cancer therapy and diagnosis. In situ chemical synthesis of the AuNFs was optimized to obtain monodisperse nanoflowers with controllable size and optical properties. Upon varying the temperature and gold ion concentrations, it was possible to tune the optical activity of the nanoparticles from 590 to 960 nm. The AuNFs exhibited good stability in the cell culture medium, and under laser irradiation. Photoacoustic imaging revealed that the NFs could be imaged in phantom systems even at low concentrations. In vitro tests revealed that the nanoflowers were effective in the photothermal therapy of a rat hepatocarcinoma (HTC) cell lineage. In addition, no toxicity was observed to mouse fibroblast (FC3H) cells incubated with the AuNFs. Our results reveal a simple method to synthesize branched anisotropic gold nanostructures, which is a promising platform for photothermal and photoacoustic therapies.

Multiangle Long-Axis Lateral Illumination Photoacoustic Imaging Using Linear Array Transducer.

Photoacoustic imaging (PAI) combines optical contrast with ultrasound spatial resolution and can be obtained up to a depth of a few centimeters. Hand-held PAI systems using linear array usually operate in reflection mode using a dark-field illumination scheme, where the optical fiber output is attached to both sides of the elevation plane (short-axis) of the transducer. More recently, bright-field strategies where the optical illumination is coaxial with acoustic detection have been proposed to overcome some limitations of the standard dark-field approach. In this paper, a novel multiangle long-axis lateral illumination is proposed. Monte Carlo simulations were conducted to evaluate light delivery for three different illumination schemes: bright-field, standard dark-field, and long-axis lateral illumination. Long-axis lateral illumination showed remarkable improvement in light delivery for targets with a width smaller than the transducer lateral dimension. A prototype was developed to experimentally demonstrate the feasibility of the proposed approach. In this device, the fiber bundle terminal ends are attached to both sides of the transducer's long-axis and the illumination angle of each fiber bundle can be independently controlled. The final PA image is obtained by the coherent sum of subframes acquired using different angles. The prototype was experimentally evaluated by taking images from a phantom, a mouse abdomen, forearm, and index finger of a volunteer. The system provided light delivery enhancement taking advantage of the geometry of the target, achieving sufficient signal-to-noise ratio at clinically relevant depths.

The effect of magnetization of natural rubber latex-coated magnetite nanoparticles on shear wave dispersion magneto-motive ultrasound.

The shear wave dispersion magneto-motive ultrasound (SDMMUS) method was recently developed to analyze the mechanical properties of a viscoelastic medium. This technique is based on the interaction of magnetic nanoparticles (MNPs) with an external magnetic field to generate a shear wave within the medium labeled with MNPs. The propagation of this wave provides information about the viscoelastic properties of the medium. In a previous work by Arsalani et al (2018), magnetite NPs were synthesized by a co-precipitation method and coated with natural rubber latex (NRL). In order to investigate the effect of NRL on the size and magnetization of MNPs, varying amounts of NRL (zero, 100 µl, and 800 µl of a stock solution of NRL) were used during the synthesis process. The results showed that MNPs prepared with 800 µl of NRL, named as MNPs-800NRL, had the smallest size and highest magnetization. In the present paper, the main objective is to investigate whether MNPs-800NRL, having the highest magnetization, is also the best option for SDMMUS experiments among others. All experiments were performed using gelatin tissue-mimicking phantoms labeled with the aforementioned MNPs. The two factors of core size and magnetization were considered, and based on the observed results, the effect of magnetization was more prominent than that of the core size on the induced displacements. MNPs coated with a thicker NRL shell, having the highest magnetization value, enhanced the sensitivity and the signal to noise ratio in SDMMUS. Various concentrations of these optimized MNPs were also examined, to investigate the lowest possible concentration for observing shear waves in the SDMMUS technique.

Photoacoustic-based thermal image formation and optimization using an evolutionary genetic algorithm

Abstract Introduction For improved efficiency and security in heat application during hyperthermia, it is important to monitor tissue temperature during treatments. Photoacoustic (PA) pressure wave amplitude has a temperature dependence given by the Gruenesein parameter. Consequently, changes in PA signal amplitude carry information about temperature variation in tissue. Therefore, PA has been proposed as an imaging technique to monitor temperature during hyperthermia. However, no studies have compared the performance of different algorithms to generate PA-based thermal images. Methods Here, four methods to estimate variations in PA signal amplitude for thermal image formation were investigated: peak-to-peak, integral of the modulus, autocorrelation of the maximum value, and energy of the signal. Changes in PA signal amplitude were evaluated using a 1-D window moving across the entire image. PA images were acquired for temperatures ranging from 36oC to 41oC using a phantom immersed in a temperature controlled thermal bath. Results The results demonstrated that imaging processing parameters and methods involved in tracking variations in PA signal amplitude drastically affected the sensitivity and accuracy of thermal images formation. The sensitivity fluctuated more than 20% across the different methods and parameters used. After optimizing the parameters to generate the thermal images using an evolutionary genetic algorithm (GA), the percentage of pixels within the acceptable error was improved, in average, by 7.5%. Conclusion Optimization of processing parameters using GA could increase the accuracy of measurement for this experimental setup and improve quality of PA-based thermal images.

Acoustic and Elastic Properties of Glycerol in Oil-Based Gel Phantoms.

Phantoms are important tools for image quality control and medical training. Many phantom materials have been proposed for ultrasound; most of them use water as the solvent, but these materials have disadvantages such as dehydration and low temporal stability if not properly stored. To overcome these difficulties, copolymer-in-oil gel was proposed as an inert and stable material; however, speed of sound for these materials is still lower than what is described for most biological tissues. Here, we propose the glycerol dispersion in oil-based gels to modify the acoustic and elastic properties of copolymer-in-oil phantoms. We manufactured copolymer-in-oil gels using styrene-ethylene/butylene-styrene (SEBS) in concentrations 8%-15%. We used 2 types of mineral oils with different viscosities. Glycerol was added in a volume fraction 0%-30% of the total amount of liquid. The acoustic (i.e., speed of sound, attenuation and backscattering) and the mechanical (i.e., density and Young's modulus) properties of the samples were within the range of values observed for soft tissues. The acoustic parameters of the samples were dependent on oil viscosity and glycerol concentration. The speed of sound ranged 1423 m/s - 1502 m/s, while the acoustic attenuation and the ultrasonic backscattering increased by adding glycerol. The density and the Young's moduli were less affected by the presence of glycerol. We conclude that glycerol can be used to control the acoustic parameters of copolymer-in-oil gels. Additionally, it opens the possibility of incorporating other oil-insoluble substances to control further properties of the phantom.

A magneto-motive ultrasound platform designed for pre-clinical and clinical applications

Abstract Introduction Magneto-motive ultrasound (MMUS) combines magnetism and ultrasound (US) to detect magnetic nanoparticles in soft tissues. One type of MMUS called shear-wave dispersion magneto-motive ultrasound (SDMMUS) analyzes magnetically induced shear waves (SW) to quantify the elasticity and viscosity of the medium. The lack of an established presets or protocols for pre-clinical and clinical studies currently limits the use of MMUS techniques in the clinical setting. Methods This paper proposes a platform to acquire, process, and analyze MMUS and SDMMUS data integrated with a clinical ultrasound equipment. For this purpose, we developed an easy-to-use graphical user interface, written in C++/Qt4, to create an MMUS pulse sequence and collect the ultrasonic data. We designed a graphic interface written in MATLAB to process, display, and analyze the MMUS images. To exemplify how useful the platform is, we conducted two experiments, namely (i) MMUS imaging to detect magnetic particles in the stomach of a rat, and (ii) SDMMUS to estimate the viscoelasticity of a tissue-mimicking phantom containing a spherical target of ferrite. Results The developed software proved to be an easy-to-use platform to automate the acquisition of MMUS/SDMMUS data and image processing. In an in vivo experiment, the MMUS technique detected an area of 6.32 ± 1.32 mm2 where magnetic particles were heterogeneously distributed in the stomach of the rat. The SDMMUS method gave elasticity and viscosity values of 5.05 ± 0.18 kPa and 2.01 ± 0.09 Pa.s, respectively, for a tissue-mimicking phantom. Conclusion Implementation of an MMUS platform with addressed presets and protocols provides a step toward the clinical implementation of MMUS imaging equipment. This platform may help to localize magnetic particles and quantify the elasticity and viscosity of soft tissues, paving a way for its use in pre-clinical and clinical studies.

Pneumoretroperitoneum, pneumomediastinum and subcutaneous emphysema after endoscopic submucosal dissection of a rectal lateral spreading tumor / Pneumorretroperitônio, pneumomediastino e enfisema subcutâneo após dissecção endoscópica da submucosa de lesão retal de crescimento lateral

Introduction: Endoscopic submucosal dissection (ESD) is an already established procedure in the treatment of gastric and esophageal cancer in its early stages. Colorectal lesions, initially approached by endoscopic mucosal resection en bloc or in fragments, are the current focus for submucosal approach, especially for superficial lateral spreading tumor of 20 mm-diameter. The experience of Japanese centers, which are reference in therapeutic endoscopy, demonstrates reduction in the rate of disease recurrence with this approach and, according to specific histopathological criteria, may avoid colectomy in some cases of malignant neoplasia. Case report: The patient was 50-year-old female. She underwent endoscopic submucosal dissection of a rectal lateral spreading tumor measuring 50 mm, located 8 cm from the anal margin. The procedure was performed without major complications, with just two points for muscle layer detachment, without gross perforation and closed with metal clips. However, the patient developed air leakage to the peritoneum, retroperitoneum, mediastinum and subcutaneous tissue, being only treated with clinical procedures and without additional intervention. Conclusion: It is vital to know and be able to apply the technique of ESD, in addition to addressing its complications, since despite the numerous benefits compared to surgery, ESD can result in serious outcomes. (AU)

Introdução: A dissecção endoscópica da submucosa (ESD) já é procedimento consagrado no tratamento do câncer gástrico e esofagiano em suas fases precoces. As lesões colorre-tais, inicialmente abordadas por mucossectomia, em bloco ou em fragmentos, são o foco atual para a abordagem submucosa, principalmente para os tumores de crescimento lateral superficial a partir de 20 mm de diâmetro. A experiência de centros japoneses, referências em endoscopia terapêutica, demonstram redução no índice de recidiva da doença com esta abordagem e, segundo critérios histopatológicos específicos, podem evitar uma colectomia em alguns casos de neoplasia maligna. Relato de caso: Trata-se de paciente de 50 anos, submetida à dissecção endoscópica da submucosa de lesão de crescimento lateral, com 50 mm, localizada no reto, a 8 cm da margem anal. O procedimento foi realizado sem maiores intercorrências, com apenas dois pontos de afastamento da muscular, sem perfuração grosseira, fechados com clipe. Entretanto, a paciente evoluiu com escape aéreo para peritônio, retroperitônio, mediastino e subcútis, sendo tratada sem intervenção adicional, apenas com manejo clínico. Conclusão: É de fundamental importância conhecer e saber aplicar a técnica da ESD, além de abordar suas complicações, uma vez que, mesmo repleta de benefícios em relação à cirurgia, ela pode apresentar desfechos graves. (AU)

Surgical complications in 2,840 cases of hemorrhoidectomy by Milligan-Morgan, Ferguson and combined techniques

The analysis of 2,840 cases of hemorrhoidectomy by open techniques of Milligan-Morgan (2,189 cases), Ferguson (341 cases) and mixed (310 cases) in 11,043 patients with hemorrhoidal disease (HD) allowed the following conclusions. The patients' acceptance of surgical indication for hemorrhoidectomy was 25.7%. Hemorrhoidectomy was more common among women (53.8%) than men (46.2%), and more accepted by women (26.5%) than men (24.8%). Hemorrhoidectomy was more common in patients of the fourth (27.7%), fifth (21.9%) and third (21.0%) decades of age. Most patients who agreed to undergo hemorrhoidectomy were those of the second (38.2%), eighth (35.9%) and ninth (34.5%) decades of age. The overall incidence of surgical complications was 3.0% (87 cases): anal stenosis (1.8%), bleeding (0.8%), worsening of anal hypotonia (0.2%), sepsis (0.1%) and systemic complications (0.1%), with no difference among the techniques used. The incidence of surgical complications by Milligan-Morgan technique was 3.0% - stenosis (1.9%), bleeding (1.9%), worsening of anal hypotonia (0.2%) and systemic complications (0.04%). The incidence of surgical complications by Ferguson's technique was 3.5% - stenosis (1.7%), bleeding (0.6%), worsening of anal hypotonia (0.6%) and sepsis (0.6%). And the incidence of surgical complications by mixed techniques was 2.5% - stenosis (1.0%), bleeding (0.3%), worsening of anal hypotonia (0.3%), sepsis (0.3%) and systemic complications (0.3%). The incidence of surgical complications according to gender was 3.0% among women and 3.2% among men, with higher incidence of stenosis in women (2.0%) and hemorrhage in men (1.1%). Surgical complications were more observed in the eighth (5.1%) and seventh (3.8%) decades of age. The incidence of anal stenosis was 1.8%, being 64.0% without hypotonia and 66.0% without anal fissure (66.0%), with annular stenosis as the most common anatomical shape (70.0%). Anal stenosis was more common among women (2.0%) presenting mean age of 38.2 years, with no relation to age decades. The most common technique for anal stenosis was single anotomy without sphincterotomy (46.0%). All cases of anal bleeding had surgical ligation of all hemorrhoidal pedicles, no matter if the bleeding site was found or not. (AU)

O seguimento de uma casuística de 2.840 hemorroidectomias pelas técnicas de Milligan-Morgan (2.189 casos), Ferguson (341 casos) e mista (310 casos) em 11.043 pacientes portadores de doença hemorroidária (DH) permitiu as seguintes conclusões. A aceitação da indicação cirúrgica para doença hemorroidária (DH), pelos pacientes, foi de 25,7%. A doença hemorroidária (DH) foi mais comum entre mulheres (53,8%) que em homens (46,2%) e a hemorroidectomia foi mais aceita pelas mulheres (26,5%) que pelos homens (24,8%). A hemorroidectomia foi mais realizada em pacientes de quarta (27,7%), quinta (21,9%) e terceira (21,0%) décadas etárias. Os pacientes que mais aceitaram a indicação cirúrgica foram os da segunda (38,2%), oitava (35,9%) e nona (34,5%) décadas etárias. A incidência global de complicações cirúrgicas foi de 3,0% (87 casos): estenose anal (1,8%), hemorragia grave (0,8%), agravamento da hipotonia anal (0,2%), sepse (0,1%) e sistêmicas (0,1%), sem diferença entre as técnicas usadas. A incidência de complicações cirúrgicas pela técnica de Milligan-Morgan foi de 3,0%: estenose (1,9%), hemorragia grave (1,9%), agravamento da hipotonia anal (0,2%) e sistêmicas (0,04%). A incidência de complicações cirúrgicas pela técnica de Ferguson foi de 3,5%: estenose (1,7%), hemorragia grave (0,6%), agravamento da hipotonia anal (0,6%) e sepse (0,6%). A incidência de complicações cirúrgicas pela técnica mista foi de 2,5%: estenose (1,0%), hemorragia grave (0,3%), agravamento da hipotonia anal (0,3%), sepse (0,3%) e sistêmicas (0,3%). A incidência de complicações cirúrgicas pelos gêneros foi de 3,0% entre as mulheres e 3,2% entre os homens, com maior incidência de estenose nas mulheres (2,0%) e hemorragia nos homens (1,1%). As décadas em que mais ocorreram complicações foram a oitava (5,1%) e a sétima (3,8%). A incidência de estenose anal foi de 1,8%, prevalecendo sem hipertonia anal (64,0%) e com fissura anal (66,0%), sendo a forma anatômica mais comum a anular (70,0%); foi mais comum entre mulheres (2,0%) com idade média de 38,2 anos, sem relação com as décadas etárias. A cirurgia corretiva da estenose anal mais usada foi a anotomia simples ou com fissurectomia sem esfincterotomia (46,0%). Em todos os casos de hemorragia anal cirúrgica foi feita ligadura de todos os pedículos da ressecção hemorroidária, independentemente de se encontrar ou não o local da hemorragia. (AU)

Leimiossarcoma oral em cão jovem / Oral Leiomyosarcoma in young dog

O leiomiossarcoma consiste em um tumor mesenquimal proveniente da musculatura lisa de rara incidênciana cavidade oral. Em cães há poucas referências quanto ao seu diagnóstico, manejo e prognóstico,dificultando a conduta. O presente trabalho tem como objetivo relatar um caso de leiomiossarcomaoral em um canino de três anos, o qual foram realizadas duas intervenções cirúrgicas, associaçãode eletroquimioterapia e bioterápico autógeno como terapia adjuvante na sobrevida do paciente. Apóso primeiro exame clínico observou-se presença de um tumor na maxila de aproximadamente 2,5cm x2,0cm de diâmetro com envolvimento ósseo, confirmado pela radiografia intra-oral da região afetada,optando-se pela realização de maxilectomia parcial esquerda do canino ao quarto pré-molar até a rafepalatina. O primeiro laudo histopatológico revelou épulis fibromatoso, porém, após três meses houverecidiva sobre o flape mucoperiostal, onde o segundo laudo revelou tratar-se de leiomiossarcomaoral. Com a evolução e acompanhamento do caso pode-se concluir que este tumor possui alta recidivalocal, e o tratamento baseia-se na ressecção do tumor com ampla margem de segurança(AU)

Leiomyosarcoma is a mesenchymal tumor originating from smooth muscle and it is rare in the oralcavity. In dogs there are few references regarding their diagnosis, management and prognosis, hinderingtheir management. This paper aims to report a case of oral leiomyosarcoma in a dog with threeyears old, which were performed two surgeries, an association electrochemotherapy and biotherapicautogenous as adjuvant therapy on patient survival. The first clinical examination showed a tumor inthe jaw about 2.5 cm x 2.0 cm in diameter with bone involvement, confirmed by intra-oral radiographsof the affected region, opting to perform the partial maxillectomy of the left canine fourth premolar tothe median raphe. The first pathologic diagnosis was fibromatous epulis; however, after three monthsthere was recurrence of the mucoperiosteum flap, where the second report revealed oral leiomyosarcoma.With the development and monitoring of the case it could be concluded that the leiomyosarcomahas a high local recurrence, and treatment is based on tumor resection with wide margin of safety(AU)

Leimiossarcoma oral em cão jovem / Oral Leiomyosarcoma in young dog

O leiomiossarcoma consiste em um tumor mesenquimal proveniente da musculatura lisa de rara incidênciana cavidade oral. Em cães há poucas referências quanto ao seu diagnóstico, manejo e prognóstico,dificultando a conduta. O presente trabalho tem como objetivo relatar um caso de leiomiossarcomaoral em um canino de três anos, o qual foram realizadas duas intervenções cirúrgicas, associaçãode eletroquimioterapia e bioterápico autógeno como terapia adjuvante na sobrevida do paciente. Apóso primeiro exame clínico observou-se presença de um tumor na maxila de aproximadamente 2,5cm x2,0cm de diâmetro com envolvimento ósseo, confirmado pela radiografia intra-oral da região afetada,optando-se pela realização de maxilectomia parcial esquerda do canino ao quarto pré-molar até a rafepalatina. O primeiro laudo histopatológico revelou épulis fibromatoso, porém, após três meses houverecidiva sobre o flape mucoperiostal, onde o segundo laudo revelou tratar-se de leiomiossarcomaoral. Com a evolução e acompanhamento do caso pode-se concluir que este tumor possui alta recidivalocal, e o tratamento baseia-se na ressecção do tumor com ampla margem de segurança

Leiomyosarcoma is a mesenchymal tumor originating from smooth muscle and it is rare in the oralcavity. In dogs there are few references regarding their diagnosis, management and prognosis, hinderingtheir management. This paper aims to report a case of oral leiomyosarcoma in a dog with threeyears old, which were performed two surgeries, an association electrochemotherapy and biotherapicautogenous as adjuvant therapy on patient survival. The first clinical examination showed a tumor inthe jaw about 2.5 cm x 2.0 cm in diameter with bone involvement, confirmed by intra-oral radiographsof the affected region, opting to perform the partial maxillectomy of the left canine fourth premolar tothe median raphe. The first pathologic diagnosis was fibromatous epulis; however, after three monthsthere was recurrence of the mucoperiosteum flap, where the second report revealed oral leiomyosarcoma.With the development and monitoring of the case it could be concluded that the leiomyosarcomahas a high local recurrence, and treatment is based on tumor resection with wide margin of safety

[Internal cardiac massage in dogs: a new technique proposition for emergency pericardiotomy--ligament traction]. / Massagem cardíaca interna em cães: proposição de nova técnica para pericardiotomia de emergência--tração ligamentar.

PURPOSE: Describe a technique of emergency pericardiotomy, named as Ligament Traction (LT), to reduce the necessary time to begin the Internal Cardiac Massage. To perform the ICM an emergency toracotomy and pericardiotomy are necessary, both in remote time. The technique usually employed is the "T" pericardiotomy, whose execution depends on the apprehension of the pericardium with an Allis forceps. This apprehension is difficult and complicates the reanimation of the patient. METHODS: Twenty canine corpses were divided into two groups: Group I--"T" pericardiotomy (n=10), and Group II--the LT technique (n=10). The LT consisted on the traction of the pericardiumphrenic ligament and the section of the pericardium next to its apex. The incision was elongated with the introduction of the fingers, also allowing the positioning of the heart in the hand of the operator and the immediate beginning of the ICM. RESULTS: Group I presented an execution period of 21.79 +/- 0.88 second, and Group II of 8.58 +/- 1.38, with p<0.0001 (highly expressive). CONCLUSION: The technique of pericardiotomy by Ligament Traction concur to outliving, because it avoids a larger time of cerebral ischemia, due to the early beginning of the circulation.

Massagem cardíaca interna em cães: proposição de nova técnica para pericardiotomia de emergência tração - ligamentar / Internal cardiac massage in dogs: a new technique proposition for emergency pericardiotomy - ligament traction

OBJETIVO: Descrever uma técnica de pericardiotomia de emergência, denominada Tração Ligamentar (TL), para diminuir o tempo necessário ao início da Massagem Cardíaca Interna (MCI). Para a MCI necessita-se de toracotomia de emergência e pericardiotomia, ambas em tempo mínimo. A técnica comumente empregada corresponde a pericardiotomia em "T", cuja execução depende da apreensão do pericárdio com uma pinça de Allis. Este pinçamento é difícil, dificultando a reanimação do paciente. MÉTODOS: Utilizou-se 20 cadáveres de cães, divididos em dois grupos de animais, sendo o Grupo I - pericardiotomia em "T" (n=10) e Grupo II - técnica proposta (n=10). A técnica de TL consistiu na tração do ligamento frenicopericárdico e da secção do pericárdio próximo ao seu ápice. A incisão foi alongada pelos dedos enquanto eram nela introduzidos e permitiu, também, o correto posicionamento do coração na mão do operador, bem como o pronto início da MCI. RESULTADOS: O Grupo I apresentou tempo de execução de 21,79 ± 0,88 segundo, e o Grupo II de 8,58 ± 1,38 segundo, sendo p<0,0001, (altamente significativo). CONCLUSÃO: A técnica de pericardiotomia por TL impede um tempo maior de isquemia cerebral, por iniciar prematuramente a circulação sangüínea, contribuindo para a sobrevida.

Massagem cardíaca interna em cães: proposição de nova técnica para pericardiotomia de emergência tração - ligamentar / Internal cardiac massage in dogs: a new technique proposition for emergency pericardiotomy - ligament traction

OBJETIVO: Descrever uma técnica de pericardiotomia de emergência, denominada Tração Ligamentar (TL), para diminuir o tempo necessário ao início da Massagem Cardíaca Interna (MCI). Para a MCI necessita-se de toracotomia de emergência e pericardiotomia, ambas em tempo mínimo. A técnica comumente empregada corresponde a pericardiotomia em "T", cuja execução depende da apreensão do pericárdio com uma pinça de Allis. Este pinçamento é difícil, dificultando a reanimação do paciente. MÉTODOS: Utilizou-se 20 cadáveres de cães, divididos em dois grupos de animais, sendo o Grupo I - pericardiotomia em "T" (n=10) e Grupo II - técnica proposta (n=10). A técnica de TL consistiu na tração do ligamento frenicopericárdico e da secção do pericárdio próximo ao seu ápice. A incisão foi alongada pelos dedos enquanto eram nela introduzidos e permitiu, também, o correto posicionamento do coração na mão do operador, bem como o pronto início da MCI. RESULTADOS: O Grupo I apresentou tempo de execução de 21,79 ± 0,88 segundo, e o Grupo II de 8,58 ± 1,38 segundo, sendo p<0,0001, (altamente significativo). CONCLUSAO: A técnica de pericardiotomia por TL impede um tempo maior de isquemia cerebral, por iniciar prematuramente a circulação sangüínea, contribuindo para a sobrevida. (AU)