Advancement in liver laparoscopic resection - development of a new surgical device

Liver resection is the standard treatment for any liver lesion. Laparoscopic liver resection is associated with lower intra-operative blood loss and fewer complications than open resection. Access to the posterior part of the right liver lobe is very uncomfortable and difficult for surgeons due the anatomic position, especially when employing laparoscopic surgery. Based on these experiences, a new laparoscopic device was developed that is capable of bending its long axis and allowing the application of radiofrequency energy in areas that were not technically accessible. The device is equipped with four telescopic needle electrodes that cause tissue coagulation after the delivery of radiofrequency energy. Ex vivo testing was performed in 2012 and 2014 at the University Hospital, Ostrava, on a porcine liver tissue. The main goal of this testing was to verify if the newly proposed electrode layout was suitable for sufficient tissue coagulation and creating a safety zone around lesions. During the ex vivo testing, the material of needle electrodes was improved to achieve the lowest possibility of adhesion. The power supply was adjusted from 20 to 120 W and the ablation time, which varied from 10 to 110 s, was monitored. Subsequently, optimal power delivery and time for coagulation was determined. This experimental study demonstrated the feasibility and safety of the newly developed device. Based on the ex vivo testing, LARA-K1 can create a safety zone of coagulation. For further assessment of the new device, an in vivo study should be performed.

Applications for a hybrid operating room in thoracic surgery: from multidisciplinary procedures to ­­image-guided video-assisted thoracoscopic surgery / Usos da sala híbrida em cirurgia torácica: de procedimentos multidisciplinares à cirurgia toracoscópica videoassistida guiada por imagem

ABSTRACT The concept of a hybrid operating room represents the union of a high-complexity surgical apparatus with state-of-the-art radiological tools (ultrasound, CT, fluoroscopy, or magnetic resonance imaging), in order to perform highly effective, minimally invasive procedures. Although the use of a hybrid operating room is well established in specialties such as neurosurgery and cardiovascular surgery, it has rarely been explored in thoracic surgery. Our objective was to discuss the possible applications of this technology in thoracic surgery, through the reporting of three cases.

RESUMO O conceito de sala híbrida traduz a união de um aparato cirúrgico de alta complexidade com recursos radiológicos de última geração (ultrassom, TC, radioscopia e/ou ressonância magnética), visando a realização de procedimentos minimamente invasivos e altamente eficazes. Apesar de bem estabelecido em outras especialidades, como neurocirurgia e cirurgia cardiovascular, o uso da sala hibrida ainda é pouco explorado na cirurgia torácica. Nosso objetivo foi discutir as aplicações e as possibilidades abertas por essa tecnologia na cirurgia torácica através do relato de três casos.

Contact force-guided catheter ablation for the treatment of atrial fibrillation: a meta-analysis of randomized, controlled trials

Contact force (CF) sensing technology allows real-time monitoring during catheter ablation for atrial fibrillation (AF). However, the effect of CF sensing technology on procedural parameters and clinical outcomes still needs clarification. Because of the inconsistent results thus far in this area, we performed a meta-analysis to determine whether CF sensing technology can improve procedural parameters and clinical outcomes for the treatment of AF. Studies examining the benefits of CF sensing technology were identified in English-language articles by searching the MEDLINE, Web of Science, and Cochrane Library databases (inception to May 2015). Ten randomized, controlled trials involving 1834 patients (1263 males, 571 females) were included in the meta-analysis (681 in the CF group, 1153 in the control group). Overall, the ablation time was significantly decreased by 7.34 min (95%CI=-12.21 to -2.46; P=0.003, Z test) in the CF group compared with the control group. CF sensing technology was associated with significantly improved freedom from AF after 12 months (OR=1.55, 95%CI=1.20 to 1.99; P=0.0007) and complications were significantly lower in the CF group than in the control group (OR=0.50, 95%CI=0.29 to 0.87; P=0.01). However, fluoroscopy time analysis showed no significantly decreased trend associated with CF-guided catheter ablation (weighted mean difference: -2.59; 95%CI=-9.06 to 3.88; P=0.43). The present meta-analysis shows improvement in ablation time and freedom from AF after 12 months in AF patients treated with CF-guided catheter ablation. However, CF-guided catheter ablation does not decrease fluoroscopy time.

Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation - prospective study of 704 cases / Método simplificado para proteção do esôfago durante a ablação por radiofrequência da fibrilação atrial - estudo prospectivo de 704 casos

Abstract Introduction: Although rare, the atrioesophageal fistula is one of the most feared complications in radiofrequency catheter ablation of atrial fibrillation due to the high risk of mortality. Objective: This is a prospective controlled study, performed during regular radiofrequency catheter ablation of atrial fibrillation, to test whether esophageal displacement by handling the transesophageal echocardiography transducer could be used for esophageal protection. Methods: Seven hundred and four patients (158 F/546M [22.4%/77.6%]; 52.8±14 [17-84] years old), with mean EF of 0.66±0.8 and drug-refractory atrial fibrillation were submitted to hybrid radiofrequency catheter ablation (conventional pulmonary vein isolation plus AF-Nests and background tachycardia ablation) with displacement of the esophagus as far as possible from the radiofrequency target by transesophageal echocardiography transducer handling. The esophageal luminal temperature was monitored without and with displacement in 25 patients. Results: The mean esophageal displacement was 4 to 9.1cm (5.9±0.8 cm). In 680 of the 704 patients (96.6%), it was enough to allow complete and safe radiofrequency delivery (30W/40ºC/irrigated catheter or 50W/60ºC/8 mm catheter) without esophagus overlapping. The mean esophageal luminal temperature changes with versus without esophageal displacement were 0.11±0.13ºC versus 1.1±0.4ºC respectively, P<0.01. The radiofrequency had to be halted in 68% of the patients without esophageal displacement because of esophageal luminal temperature increase. There was no incidence of atrioesophageal fistula suspected or confirmed. Only two superficial bleeding caused by transesophageal echocardiography transducer insertion were observed. Conclusion: Mechanical esophageal displacement by transesophageal echocardiography transducer during radiofrequency catheter ablation was able to prevent a rise in esophageal luminal temperature, helping to avoid ...

Resumo Introdução: Apesar de rara, a fístula átrio-esofágica é uma das complicações mais temidas na ablação por radiofrequência da fibrilação atrial pelo alto risco de mortalidade. Objetivo: Este é um estudo prospectivo controlado, realizado durante a ablação por radiofrequência da fibrilação atrial regular, para testar se o deslocamento do esôfago ao manipular o transdutor de ecocardiografia transesofágica poderia ser usado para a proteção de esôfago. Métodos: Setecentos e quatro pacientes (158 mulheres e 546 homens [22,4%/77,6%]; 52,8±14 [17-84] anos), com EF média igual a 0,66±0,8 e com fibrilação atrial refratária ao tratamento medicamentoso, foram submetidos à terapia híbrida com ablação por radiofrequência (isolamento convencional das veias pulmonares e ninhos de fibrilação atrial e ablação de taquicardia de background) com deslocamento do esôfago o mais longe possível do alvo da radiofrequência por manuseio do transdutor de ecocardiografia transesofágica. A temperatura luminal esofágica foi monitorada com e sem deslocamento em 25 pacientes. Resultados: O deslocamento esofágico significativo foi de 4 a 9,1 centímetros (5,9±0,8 cm). Em 680 dos 704 pacientes (96,6%), isso foi o suficiente para permitir a entrega completa e segura de radiofrequência (30W/40ºC/cateter irrigado ou 50W/60ºC/cateter de 8 milímetros) sem sobreposição do esôfago. As alterações médias de temperatura luminal esofágica com e sem deslocamento de esôfago foram de 0,11±0,13ºC versus 1,1±0,4ºC, respectivamente, P<0,01. A radiofrequência teve que ser interrompida em 68% dos pacientes sem deslocamento de esôfago devido ao aumento da temperatura luminal esofágica. Não houve nenhum caso, suspeito ou confirmado, de fístula átrio-esofágica. Foram observados apenas dois sangramentos superficiais causados por inserção do transdutor de ecocardiografia transesofágica. Conclusão: O deslocamento mecânico do esôfago pelo transdutor de ecocardiografia transesofágico durante ...

Ablacao de Fibrilacao Atrial por Mapeamento Eletroanatomico: Eficacia e Fatores de Recorrencia / Atrial Fibrillation Ablation by Use of Electroanatomical Mapping: Efficacy and Recurrence Factors

Fundamento: A ablação por cateter de radiofrequência guiada por mapeamento eletroanatômico é, atualmente, uma importante opção terapêutica para o tratamento da fibrilação atrial. A complexidade do procedimento, as diferentes técnicas e a diversidade de pacientes dificultam a reprodução dos resultados bem como a indicação do procedimento. Objetivo: Avaliar a eficácia e os fatores relacionados à recorrência de fibrilação atrial. Métodos: Estudo de coorte prospectivo com pacientes consecutivos submetidos ao tratamento de fibrilação atrial por ablação e mapeamento eletroanatômico. Foram incluídos os seguintes pacientes: idade acima de 18 anos; portadores de fibrilação atrial paroxística, persistente ou persistente de longa duração; com registro de fibrilação atrial em eletrocardiograma, Holter ou ergometria (duração > 15 minutos); com sintomas associados aos episódios de fibrilação atrial; e apresentando refratariedade a, pelo menos, duas drogas antiarrítmicas (entre elas amiodarona) ou impossibilidade do uso de drogas antiarrítmicas. Resultados: Foram incluídos 95 pacientes (idade 55 ± 12 anos, 84% homens, CHADS2 médio = 0,8) que realizaram 102 procedimentos com seguimento mediano de 13,4 meses. A taxa livre de recorrência após o procedimento foi de 75,5% após 12 meses. Os pacientes portadores de fibrilação atrial paroxística e fibrilação atrial persistente apresentaram recorrência de 26,9% versus 45,8% dos pacientes portadores de fibrilação atrial persistente de longa duração (p = 0,04). Das variáveis analisadas, o tamanho do átrio esquerdo demonstrou ser preditor independente de recorrência de fibrilação atrial após ...

Background: Radiofrequency catheter ablation guided by electroanatomical mapping is currently an important therapeutic option for the treatment of atrial fibrillation. The complexity of the procedure, the several techniques used and the diversity of the patients hinder the reproduction of the results and the indication for the procedure. Objective: To evaluate the efficacy and factors associated with recurrence of atrial fibrillation. Methods: Prospective cohort study with consecutive patients submitted to atrial fibrillation ablation treatment guided by electroanatomical mapping. The inclusion criteria were as follows: minimum age of 18 years; presence of paroxysmal, persistent or long-standing persistent AF; AF recording on an electrocardiogram, exercise testing or Holter monitoring (duration longer than 15 minutes); presence of symptoms associated with AF episodes; AF refractoriness to, at least, two antiarrhythmic drugs, one of which being amiodarone, or impossibility to use antiarrhythmic drugs. Results: The study included 95 patients (age 55 ± 12 years, 84% men, mean CHADS2 = 0.8) who underwent 102 procedures with a median follow-up of 13.4 months. The recurrence-free rate after the procedure was 75.5% after 12 months. Atrial fibrillation recurred as follows: 26.9% of patients with paroxysmal and persistent atrial fibrillation; 45.8% of patients with long-standing persistent atrial fibrillation (p = 0.04). Of the analyzed variables, the increased size of the left atrium has proven to be an independent predictor of atrial fibrillation recurrence after the procedure (HR = 2.58; 95% CI: 1.26-4.89). Complications occurred in 4.9% of the procedures. Conclusion: Atrial fibrillation ablation guided by electroanatomical mapping has shown good efficacy. The increase in left atrium size was associated with atrial fibrillation recurrence. .

Monopolar Radiofrequency Ablation Using a Dual-Switching System and a Separable Clustered Electrode: Evaluation of the In Vivo Efficiency

OBJECTIVE: To determine the in vivo efficiency of monopolar radiofrequency ablation (RFA) using a dual-switching (DS) system and a separable clustered (SC) electrode to create coagulation in swine liver. MATERIALS AND METHODS: Thirty-three ablation zones were created in nine pigs using a DS system and an SC electrode in the switching monopolar mode. The pigs were divided into two groups for two experiments: 1) preliminary experiments (n = 3) to identify the optimal inter-electrode distances (IEDs) for dual-switching monopolar (DSM)-RFA, and 2) main experiments (n = 6) to compare the in vivo efficiency of DSM-RFA with that of a single-switching monopolar (SSM)-RFA. RF energy was alternatively applied to one of the three electrodes (SSM-RFA) or concurrently applied to a pair of electrodes (DSM-RFA) for 12 minutes in in vivo porcine livers. The delivered RFA energy and the shapes and dimensions of the coagulation areas were compared between the two groups. RESULTS: No pig died during RFA. The ideal IEDs for creating round or oval coagulation area using the DSM-RFA were 2.0 and 2.5 cm. DSM-RFA allowed more efficient RF energy delivery than SSM-RFA at the given time (23.0 +/- 4.0 kcal vs. 16.92 +/- 2.0 kcal, respectively; p = 0.0005). DSM-RFA created a significantly larger coagulation volume than SSM-RFA (40.4 +/- 16.4 cm3 vs. 20.8 +/- 10.7 cm3; p < 0.001). Both groups showed similar circularity of the ablation zones (p = 0.29). CONCLUSION: Dual-switching monopolar-radiofrequency ablation using an SC electrode is feasible and can create larger ablation zones than SSM-RFA as it allows more RF energy delivery at a given time.

Saline-Coupled Bipolar Sealing in Simultaneous Bilateral Total Knee Arthroplasty

BACKGROUND: The efficacy of saline-coupled bipolar sealing devices in joint arthroplasty is uncertain, and the utility in simultaneous bilateral total knee arthroplasty (TKA) has not been reported. METHODS: This study compares the use of bipolar sealing and conventional electrocautery in 71 consecutive patients. The experimental and control groups were matched for age, sex, body mass index, American Society of Anesthesiologists (ASA) classification, and preoperative hemoglobin. Variables of interest included blood loss, transfusion requirements, and operative characteristics. RESULTS: In comparison to patients treated with conventional electrocautery, those treated with the bipolar sealer were 35% less likely to require transfusion. The median number of transfusions per case was also significantly lower in the experimental group. Hemoglobin change, total blood loss, and length of stay were not significantly different between the groups. The experimental group had longer operative times. CONCLUSIONS: Bipolar sealing shows promise as a blood loss reduction tool in simultaneous bilateral TKA. The marginal savings attributed to reduced transfusion rates with use of the bipolar sealer did not exceed the additional per-case expense of using the device. The decision to use the device with the goal of less blood loss must come with the additional expense associated with its use.

As linhas virtuais criadas com o sistema de mapeamento eletroanatômico ensite são de fato contínuas? / Are the virtual lines created with the ensite electroanatomical mapping system really continuous?

FUNDAMENTO: O sistema de mapeamento eletro anatômico Ensite Navx é muito usado na ablação por radiofrequência (RF) da fibrilação atrial, ajudando na confecção de lesões lineares. Contudo, a correspondência da linha virtual criada pelo Ensite com a lesão patológica ainda não foi avaliada. OBJETIVO: Avaliar a continuidade da linha virtual criada pelo Ensite em modelo suíno. MÉTODOS: Realizamos ablação linear por RF (cateter de 8 mm e irrigado) em ambos os átrios de 14 suínos (35 kg) guiada pelo EnSite. Os animais foram sacrificados 14 dias pós-ablação para análise macroscópica e histológica. RESULTADOS: Foram confeccionadas 23 lesões lineares em átrio direito e 21 em átrio esquerdo dos 14 animais. A potência, temperatura e impedância médias das aplicações foram de 56 W, 54 ºC e 231 Ω para o cateter de 8mm, e de 39 W, 37 ºC e 194 Ω para o cateter irrigado. Todas (100%) as linhas foram identificadas nas faces epicárdica e endocárdica, denotando transmuralidade. À macroscopia, as lesões eram extensas e pálidas, com 3,61 cm de comprimento e 0,71 cm de profundidade e contínuas. A transmuralidade das lesões foi confirmada pela microscopia. Houve correspondência na localização das linhas do mapa virtual com as da peça anatômica em 21 das 23 (91,3%) das linhas do átrio direito e 19/21 (90,4%) do átrio esquerdo. CONCLUSÃO: Nesse modelo, as linhas criadas no mapa virtual pelo sistema EnSiteNavX se correlacionam a lesões lineares transmurais contínuas na peça anatômica, sugerindo que esse método é adequado para a ablação linear da fibrilação atrial.

BACKGROUND: EnSiteNavx electroanatomic mapping system is widely used in radiofrequency (RF) atrial fibrillation ablation, helping the creation of linear lesions. However, the correspondence of the virtual line created by EnSite with the pathological lesion has not yet been evaluated. OBJECTIVE: to assess the continuousness of Ensite-guided virtual lines in a swine model. METHODS: we performed RF ablation linear lesions (8mm and irrigated catheters tips) in both atria of 14 pigs (35Kg) guided by the EnSite. The animals were sacrificed 14 days post-ablation for macroscopic and histological analysis. RESULTS: a total of 23 lines in the right atrium and 21 lines in the left atrium were created in 14 animals. The medium power, impedance and temperature applications were 56 W, 54 ºC and 231 Ω for the 8mm tip, and 39W, 37ºC, 194 Ω for the irrigated tip catheter, respectively. All (100%) lines were identified on the epicardial and endocardial surfaces, denoting transmurality. At macroscopic examination, lesions were extensive and pale, continuous, with 3.61 cm long and 0.71 cm deep. The transmurality of the lesions was confirmed by microscopy. There was a correlation in the location of the lines at the virtual map and the anatomical lesions in 21 of 23 (91.3%) of the right atrium and 19/21 (90.4%) of the left atrium. CONCLUSION: In this model, the lines created in the virtual map by EnSiteNavX system correspond to continuous transmural linear lesions in anatomical specimen, suggesting that this method is suitable for linear ablation of atrial fibrillation.

Percutaneous closure of using Occlusion DeviceOstium Secundum Septal defect amplatzer occlusion device: Experience of cardiology department, Hedi Chaker Hospital, Sfax, Tunisia

To report our clinical experience with transcatheter closure of ostium secundum atrial septal defects [OS ASDs] using Amplatzer septal occluder. It's a retrospective study conducted between October 2005 and April 2010 and involving 34 patients. The procedures were conducted in the hemodynamic laboratory under general anesthesia with transthoracic [TTE] and transoesophageal echocardiographic [TEE] monitoring. Clinical and echocardiography assessments of the patients were conducted within 24 hours post procedure and several months after the procedure. From the 34 patients, 28 [82%] were females. The middle age was 27.5 years. The mean ASD diameter was 19.4 mm by TTE; 18.1 mm [12-38] by TEE, and 23.4 by angiography. The average size of the implanted devices was 23.2 mm ranging from 10 to 34 mm. The final success rate of the procedure was 90.9% [30/33]. One patient was excluded from transcatheter occlusion and three patients [8,6%] had complications including two prosthesis migrations and one large residual shunting. A total of 4 patients [11.7%] underwent surgery. No major complication [thromboembolic events, obstruction of intracardiac structures, cardiac perforation, device embolization and endocarditis] or death has occurred during follow-up and all devices were securely anchored without any persistent residual shunts. Compared to previous data of the literature, percutaneous closure of OS ASDs using Amplatzer device appears safe and effective according to our experience of the cardiology department of Hedi Chaker Hospital

Dual Switching Monopolar Radiofrequency Ablation Using a Separable Clustered Electrode: Comparison with Consecutive and Switching Monopolar Modes in Ex Vivo Bovine Livers

OBJECTIVE: To compare the in-vitro efficiency of dual-switching monopolar (DSM) radiofrequency ablation (RFA) using a separable clustered electrode (Octopus(R) electrodes) with consecutive monopolar (CM) and switching monopolar (SM) RFA techniques to create an ablative zone in the explanted bovine liver. MATERIALS AND METHODS: For DSM-RFA, we used a prototype, three-channel, dual generator RFA Unit and Octopus(R) electrodes with three, 17 gauge internally cooled electrodes. The RFA Unit allowed simultaneous radiofrequency (RF) energy delivery to two electrodes of the Octopus(R) electrodes as well as automatic switching among the three electrode pairs according to the impedance changes. RF energy was sequentially applied to one of the three electrodes for 24 minutes (group A; CM mode, n = 10) or alternatively applied for 12 minutes (group B; SM mode, n = 10) or concurrently applied to a pair of electrodes for 12 minutes (group C; DSM mode, n = 10) in explanted bovine livers. Changes in the impedance and current during RFA as well as the dimensions of the thermal ablative zones were compared among the three groups. RESULTS: The mean, delivered RF energy amounts in groups A, B, and C were 63.15 +/- 8.6 kJ, 72.13 +/- 5.4 kJ, and 106.08 +/- 13.4 kJ, respectively (p < 0.001). The DSM mode created a significantly larger ablation volume than did the other modes, i.e., 68.1 +/- 10.2 cm3 (group A), 92.0 +/- 19.9 cm3 (group B), and 115.1 +/- 14.0 cm3 (group C) (p < 0.001). The circularity in groups A, B, and C were 0.84 +/- 0.06, 0.87 +/- 0.04 and 0.90 +/- 0.03, respectively (p = 0.03). CONCLUSION: DSM-RFA using Octopus(R) electrodes can help create large ablative zones within a relatively short time.

Percutaneous Radiofrequency Ablation with Multiple Electrodes for Medium-Sized Hepatocellular Carcinomas

OBJECTIVE: To prospectively evaluate the safety and short-term therapeutic efficacy of switching monopolar radiofrequency ablation (RFA) with multiple electrodes to treat medium-sized (3.1-5.0 cm), hepatocellular carcinomas (HCC). MATERIALS AND METHODS: In this prospective study, 30 patients with single medium-sized HCCs (mean, 3.5 cm; range, 3.1-4.4 cm) were enrolled. The patients were treated under ultrasonographic guidance by percutaneous switching monopolar RFA with a multichannel RF generator and two or three internally cooled electrodes. Contrast-enhanced CT scans were obtained immediately after RFA, and the diameters and volume of the ablation zones were then measured. Follow-up CT scans were performed at the first month after ablation and every three months thereafter. Technical effectiveness, local progression and remote recurrence of HCCs were determined. RESULTS: There were no major immediate or periprocedural complications. However, there was one bile duct stricture during the follow-up period. Technical effectiveness was achieved in 29 of 30 patients (97%). The total ablation time of the procedures was 25.4 +/- 8.9 minutes. The mean ablation volume was 73.8 +/- 56.4 cm3 and the minimum diameter was 4.1 +/- 7.3 cm. During the follow-up period (mean, 12.5 months), local tumor progression occurred in three of 29 patients (10%) with technical effectiveness, while new HCCs were detected in six of 29 patients (21%). CONCLUSION: Switching monopolar RFA with multiple electrodes in order to achieve a sufficient ablation volume is safe and efficient. This method also showed relatively successful therapeutic effectiveness on short-term follow up for the treatment of medium-sized HCCs.

Uso da radiofrequência bipolar para o tratamento da fibrilação atrial durante cirurgia cardíaca / Use of bipolar radiofrequency for the treatment of atrial fibrillation during cardiac surgery / Uso de la radiofrecuencia bipolar para el tratamiento de la fibrilación atrial durante cirugía cardíaca

FUNDAMENTO: O tratamento da fibrilação atrial com dispositivo de ablação de tecidos por radiofrequência bipolar em concomitância à cirurgia cardíaca tem se mostrado método eficaz no tratamento desta arritmia. OBJETIVO: Descrever a experiência inicial do Instituto Nacional de Cardiologia no tratamento cirúrgico da fibrilação atrial com uso de dispositivo de radiofrequência bipolar em pacientes submetidos à cirurgia cardíaca, relatando o resultado de acompanhamento pós-operatório de um ano. MÉTODOS: Entre janeiro de 2008 e março de 2009, 47 pacientes (36 mulheres) consecutivos, com idade média de 53,7 ± 10,6 anos, apresentando fibrilação atrial por um período médio de 34,6 meses (3 a 192 meses) foram submetidos à ablação cirúrgica desta arritmia, por radiofrequência bipolar, durante o procedimento que motivou a indicação da cirurgia. Oito apresentavam fibrilação atrial intermitente e 39, contínua. Oitenta e um por cento foram submetidos à cirurgia valvar como procedimento principal. Esta é uma análise retrospectiva, observacional, com avaliação de um ano de pós-operatório das variáveis clínicas e de Holter 24 h. RESULTADOS: Dos 47 pacientes, 40 sobreviveram um ano. Desses, 33 foram submetidos a Holter 24 h, em um intervalo médio de 401 dias após a cirurgia. Encontrou-se a seguinte distribuição de ritmos: 24 (73 por cento) sinusal, 5 (15 por cento) fibrilação atrial, três (9 por cento) Flutter atrial e um (3 por cento) ritmo juncional. Foram observados dois acidentes vasculares encefálicos, sendo um associado à arritmia supraventricular. CONCLUSÃO: A ablação cirúrgica de fibrilação atrial com dispositivo de radiofrequência bipolar concomitante à cirurgia cardíaca é método eficaz para o tratamento desta arritmia.

BACKGROUND: Atrial fibrillation with tissue ablation device through bipolar radiofrequency in conjunction with cardiac surgery has proven to be an effective method to treat this arrhythmia. OBJECTIVE: Describe the initial experience of the Instituto Nacional de Cardiologia in the surgical treatment of atrial fibrillation using bipolar radiofrequency device in patients undergoing cardiac surgery, reporting the results of postoperative follow-up of one year. METHODS: Between January 2008 and March 2009, 47 consecutive patients (36 women), with mean age of 53.7 ± 10.6 years, with atrial fibrillation for a mean period of 34.6 months (3-192 months) underwent surgical ablation of this arrhythmia, through bipolar radiofrequency during the procedure which led to the indication of surgery. Eight of them showed intermittent atrial fibrillation and 39, continued. Eighty-one percent underwent valve surgery as the main procedure. This is a one-year postoperative retrospective, observational evaluation of clinical variables and 24-h Holter. RESULTS: Out of the 47 patients, 40 survived one year. Out of these, 33 underwent 24 h Holter, at an average interval of 401 days after the surgery. The following rhythm distribution was found: 24 (73.0 percent) sinus, five (15.0 percent) atrial fibrillation, three (9.0 percent) atrial Flutter and one (3.0 percent) junctional rhythm. Two cerebrovascular accidents were observed, one of which was associated with supraventricular arrhythmia. CONCLUSION: Surgical ablation of atrial fibrillation with bipolar radiofrequency device concomitant with cardiac surgery is an effective method for treating this arrhythmia.

FUNDAMENTO: El tratamiento de la fibrilación atrial con dispositivo de ablación de tejidos por radiofrecuencia bipolar en concomitancia con la cirugía cardíaca se muestra un método eficaz en el tratamiento de esta arritmia. OBJETIVO: Describir la experiencia inicial del Instituto Nacional de Cardiología en el tratamiento quirúrgico de la fibrilación atrial con uso de dispositivo de radiofrecuencia bipolar en pacientes sometidos a cirugía cardíaca, relatando el resultado de seguimiento postoperatorio de un año. MÉTODOS: Entre enero de 2008 y marzo de 2009, 47 pacientes (36 mujeres) consecutivos, con edad promedio de 53,7 ± 10,6 años, presentando fibrilación atrial por un período promedio de 34,6 meses (3 a 192 meses) fueron sometidos a ablación quirúrgica de esta arritmia, por radiofrecuencia bipolar, durante el procedimiento que motivó la indicación de la cirugía. Ocho presentaban fibrilación atrial intermitente y 39, continua. El 81 por ciento fue sometido a cirugía valvular como procedimiento principal. Éste es un análisis retrospectivo, observacional, con evaluación de un año de postoperatorio de las variables clínicas y de Holter 24 h. RESULTADOS: De los 47 pacientes, 40 sobrevivieron un año. De ellos, 33 fueron sometidos a Holter 24 h, en un intervalo promedio de 401 días después de la cirugía. Se encontró la siguiente distribución de ritmos: 24 (73 por ciento) sinusal, 5 (15 por ciento) fibrilación atrial, tres (9 por ciento) flutter atrial y un (3 por ciento) ritmo de la unión. Se observaron dos accidentes vasculares encefálicos, siendo uno asociado a la arritmia supraventricular. CONCLUSIÓN: La ablación quirúrgica de fibrilación atrial con dispositivo de radiofrecuencia bipolar concomitante a la cirugía cardíaca es método eficaz para el tratamiento de esta arritmia.

Utilidade do Ultrassom intracardíaco no isolamento de veias pulmonares usando cateter-balão a laser / Utility of intracardiac ultrasound imaging to guide pulmonary vein ablation using laser balloon catheter / Utilidad del ultrasonido intracardíaco en el aislamiento de venas pulmonares usando catéter-balón láser

Fundamento: O isolamento das veias pulmonares (IVP) tem sido usado como endpoint para a ablação da fibrilação atrial (FA) com cateter balão. Objetivo: Determinar a utilidade do ultrassom intracardíaco (USIC) para guiar o IVP, usando cateter balão a laser. Métodos: 59 VP foram ablacionadas em 27 cães. Imagens de Doppler foram usadas para identificar os vazamentos do fluxo sanguíneo entre a VP e o balão. Após cada liberação de energia, o cateter de mapeamento circular foi reposicionado para verificar se o isolamento tinha sido obtido. A posição de vazamento foi então correlacionada com a posição do gap no estudo patológico. A análise de regressão logística multivariada foi realizada. Resultados: Cinquenta e nove VP foram submetidas à ablação. O tempo médio de energia liberada foi de 279±177 seg., o diâmetro médio do balão era de 23±3 mm, e o comprimento médio do balão era 25±4 mm. O isolamento completo foi obtido em 38/59 (64 por cento), e foi significantemente mais comum sem vazamento: [30/38 (79 por cento) versus 8/23 (35 por cento), p<0,001]. Isso foi independente do tempo de aplicação (302±223 seg. vs. 266±148 sec., p=ns), potência (3,5 W/cm, 4,5 W/cm, e 5,5 W/cm), diâmetro do balão (24± 3 mm vs. 22± 3 mm, p= ns) e comprimento (27±4 mm vs. 24±4 mm, p=ns). O valor preditivo positivo para previsão de isolamento completo foi de 65 por cento e o valor preditivo negativo foi 83 por cento. Conclusão: Um vazamento identificável entre a VP e o dispositivo de ablação por cateter-balão observado no USIC é preditor de menor taxa de isolamento de VP mais baixas. O USIC pode ser útil para detectar vazamentos a fim de evitar o uso ineficaz de aplicação energia durante a ablação circunferencial da VP. Isto também pode ser útil quando outras energias são utilizadas.

Background: Pulmonary vein isolation (PVI) with balloon catheter has been used as the endpoint for AF ablation. Objective: To determine the usefulness of intracardiac ultrasound (ICUS) to guide PVI using laser balloon catheter. Methods: 59 PVs were ablated in 27 dogs. Doppler imaging was used to identify blood flow leaks between PV and balloon. After each energy delivery, the circular mapping catheter was repositioned to check if isolation had been achieved. The leak position was then correlated with the gap position at the pathological study. Multivariate logistic regression analysis was undertaken. Results: 59 PV were ablated. Mean burn time was 279±177 sec, mean balloon diameter was 23±3 mm, and mean balloon length was 25±4 mm. Complete isolation was achieved in 38/59 (64 percent) cases, and it was significantly more common when there was no leak: [30/38 (79 percent) versus 8/23 (35 percent), p<0.001]. This occurred regardless of time of laser application (302±223 sec. vs. 266±148 sec., p=ns), laser power (3.5 W/cm, 4.5 W/cm, and 5.5 W/cm), balloon diameter (24± 3 mm vs. 22± 3 mm, p=ns) and length (27±4 mm vs. 24±4mm, p=ns). The positive predictive value for predicting incomplete isolation was 65 percent and the negative predictive value was 83 percent. Conclusion: An identifiable leak between PV and the LBA device seen at the ICUS is predictive of lower PV isolation rates. ICUS may be useful for leak detection to avoid ineffective energy application during circumferential PV ablation. This could also be helpful when other types of energy are used.

Fundamento: Se usó el aislamiento de las venas pulmonares (AVP) como endpoint para la ablación de la fibrilación atrial (FA) con catéter-balón. Objetivo: Determinar la utilidad del ultrasonido intracardíaco (USIC) para guiar el AVP, usando catéter-balón láser. Métodos: Se ablacionaron 59 VP en 27 perros. Se usaron imágenes de Doppler para identificar los derrames del flujo sanguíneo entre la VP y el balón. Tras cada liberación de energía, se reposicionó el catéter de mapeamiento circular para verificar si se obtuvo el aislamiento. Se correlaccionó, entonces, la posición del derrame con la posición del gap en el estudio patológico. Se realizó el análisis de regresión logística multivariada. Resultados: Se sometieron 59 VP a la ablación. El tiempo promedio de energía liberada fue de 279±177 seg., el diámetro promedio del balón era de 23±3 mm, y la largura promedio del balón era 25±4 mm. Se obtuvo el aislamiento completo en 38/59 (64 por ciento), y fue significantemente más común sin derrame: [30/38 (79 por ciento) versus 8/23 (35 por ciento), p<0,001]. Eso fue independiente del tiempo de aplicación (302±223 seg. vs. 266±148 sec., p=ns), potencia (3,5 W/cm, 4,5 W/cm, y 5,5 W/cm), diámetro del balón (24± 3 mm vs. 22± 3 mm, p= ns) y largura (27±4 mm vs. 24±4 mm, p=ns). El valor predictivo positivo para la previsión del aislamiento completo fue del 65 por ciento y el valor predictivo negativo fue del 83 por ciento. Conclusión: Un derrame identificable entre la VP y el dispositivo de ablación por catéter-balón observado en el USIC es predictor de menor tasa del aislamiento de la VP más baja. El USIC puede ser útil para detectar derrames a fin de evitar el uso ineficaz de la aplicación de la energía durante la ablación circunferencial de la VP. Ello también puede ser útil cuando se utilizan otras energías.

Tratamiento no farmacológico de la fibrilación auricular / Non pharmacological treatment of atrial fibrillation

La fibrilación auricular es la arritmia que genera más hodpitalizaciones y gastos en atención de la salud. La prevalencia de la fibrilación auricular aumenta con la edad de la población y otros factores. Estimamos que en Venezuela puede haber unas 230.000 personas que sufren. El tratamiento farmacológico con los antiarrítmicos disponibles no ha producido una solución satisfactoria al problema. De hecho se estima que después de un año de seguimiento, los antiarrítmocos más eficaces sólo alcanzan a mantener en ritmo sinusal a menos del 30% los pacientes. Este fallo de los antirrítmicos ha estimulado la investigación para conseguir métodos no farmacológicos para el tratamiento de la fibrilación auricular. En 1982 se describión la ablación del nodo AV para el control de la respuesta ventricular y, después, la ablación quirúrgica y por catéter para restablecer el ritmo sinusal. Presentamos una revisión acerca del tratamiento no farmacológico de la fibrilación auricular, con particular énfacis en la ablación por catéter, y nuestros resultados en la serie inicial de pacientes que hemos tratado por este medio en mérida, Venezuela.

Atrial fibrillation (AF) is the arrhythmia that causes the highest number of hospital admissions and health expenses. The prevalence of AF increases with age and several other factors. We estimate that 230,000 persons suffer from AF in Venezuela. Antiarrhytmic drugs have not been found to be adequate for AF treatment. Indeed, at one-year follow-up, recent research has found that the most powerful antiarrhytmics drugs are able to maintain sinus rhythm in less than 30% of patients. This failure of pharmacotherapy stimulated researh to find non-pharmacological means to treat AF. AV nodal ablation was introduced in 1982 for ventricular rate response control and surgical and catheter ablation techniques were later designed to achieve sinus rhythm. In this article we review the non-pharmacological treatment of AF putting special emphasis on catheter ablation. We also present some preliminary results obtained from the theatment of patients in Mérida(Venezuela).

Percutaneous Radiofrequency Ablation of Hepatocellular Carcinomas Adjacent to the Gallbladder with Internally Cooled Electrodes: Assessment of Safety and Therapeutic Efficacy

OBJECTIVE: The objective of this study was to evaluate the safety and therapeutic efficacy of percutaneous radiofrequency (RF) ablation for the treatment of hepatocellular carcinomas (HCCs) adjacent to the gallbladder with the use of internally cooled electrodes. MATERIALS AND METHODS:We retrospectively assessed 45 patients with 46 HCCs (mean size, 2.2 cm) adjacent to the gallbladder ( or =3 cm) and tumor location (a tumor that abutted the gallbladder) were associated with an increased risk of early incomplete treatment. No variable was significantly associated with local tumor progression. CONCLUSION: Percutaneous RF ablation of HCCs adjacent to the gallbladder using an internally cooled electrode is a safe and effective treatment. Significant risk factors that lead to early incomplete treatment include tumor size, tumor location and electrode direction.

Tratamento cirúrgico da fibrilação atrial crônica com eletrocautério convencional em cirurgia valvar mitral / Surgical treatment of chronic atrial fibrillation with conventional electrocautery in mitral valve surgery

OBJETIVO: Avaliar os resultados do tratamento cirúrgico da fibrilação atrial por ablação da parede posterior atrial esquerda utilizando o eletrocautério, em cirurgia valvar mitral. MÉTODOS: De maio de 2004 a dezembro de 2006, 23 pacientes foram submetidos a correção cirúrgica de valvopatia mitral e ao tratamento da fibrilação atrial utilizando o eletrocautério convencional para a realização de linhas de ablação no endocárdio atrial esquerdo. A idade média dos pacientes era de 59 anos, sendo 60,8% do sexo feminino. A média do diâmetro atrial esquerdo era de 50,3 ± 5,09 mm e a fração de ejeção do ventrículo esquerdo de 53,6 ± 11,03%. RESULTADOS: O tempo médio de circulação extracorpórea foi de 52,5 ± 13,3 min; pinçamento aórtico, 35,6 ± 12,9 min; ablação do endocárdio atrial, 3,05 ± 0,16 min. Todos os pacientes estavam livres de fibrilação atrial após o procedimento; na alta hospitalar, 69,5%; no 6º mês, 91,3%; no 12º mês, 76,4%; no 18º e 24º meses, 68,4%. No 12º mês, a média do diâmetro atrial esquerdo era de 42,1 ± 3,5 mm; a fração de ejeção do ventrículo esquerdo era de 59,2 ± 3,48%; e a contração atrial esquerda estava presente em 68,8 por cento de todos os pacientes. CONCLUSÃO: O tratamento cirúrgico da fibrilação atrial com eletrocautério, em cirurgia valvar mitral, foi capaz de determinar a reversão dessa arritmia a um número significativo de pacientes durante um seguimento clínico de curto e médio prazo, sem mortalidade e com baixa morbidade.

OBJECTIVE: To evaluate the results of the surgical treatment of atrial fibrillation for ablation of the posterior left atrial wall using electrocautery in mitral valve surgery. METHODS: From May 2004 to December 2006, 23 patients underwent surgical correction of mitral valve disease and treatment of atrial fibrillation using the conventional electrocautery for the accomplishment of lines of endocardial ablation in the left atrium. The mean age of the patients was 59 years, and 60.8% were female. The left atrium mean diameter was 50.3 ± 5.09 mm and the left ventricular ejection fraction was 53.6 ± 11.03%. RESULTS: The mean time of extracorporeal circulation was 52.5 ± 13.3 min; aortic clamping, 35.6 ± 12.9 min; atrial ablation, 3.05 ± 0.16 min. All the patients were free of atrial fibrillation after the procedure; on hospital discharge, 69.5%; at 6 months, 91.3%; at 12 months, 76.4%; at 18 months, and at 24 months, 68.4%. At 12 months, left atrium mean diameter was 42.1 ± 3.5 mm; left ventricular ejection fraction was 59.2 ± 3.48%; In addition, left atrial contraction was present in 68.8% of the patients. CONCLUSION: The surgical treatment of the atrial fibrillation with electrocautery in mitral valve surgery was capable to determine the reversion of this arrhythmia in a significant number of patients during short- and middle-term clinical follow-up without mortality and fewer complications.

Nuevo dispositivo para el manejo de la vía aérea y entubación difícil: catéter orotraqueal articulado / New device for the managing of the airway and entubación difficult: catheter orotraqueal articulated

Presentar un nuevo dispositivo para el manejo de la vía aérea y la intubación difícil. Materiales y métodos. Presentación de un caso de vía aérea difícil y de la técnica para la utilización del catéter orotraqueal articulado, el cual es un dispositivo de cloruro de polivinilo que consta de dos componentes, uno distal de ubicación traqueal y otro proximal, unidos entre sí de manera laxa. El componente distal, con una guía metálica en su interior, es introducido por medio de laringoscopia directa, siguiendo un trayecto posterior a la epiglotis. Se retira la guía metálica, se conecta a los circuitos respiratorios por medio de un adaptador y se ventila a través de él hasta evidenciar trazado de capnografía y para mantener la oxigenación. Se retira el adaptador, se alinean los dos componentes y se introduce el tubo orotraqueal empleando el catéter articulado como guía. Una vez el tubo pasa a la tráquea, el catéter articulado se retira y se ventila a través del tubo traqueal. Conclusiones. El catéter articulado se presenta como una alternativa útil en el manejo de la vía aérea y la intubación difícil, por su facilidad de uso, la relativamente baja resistencia para la ventilación y su bajo costo. Se plantea como una buena opción en los algoritmos de vía aérea difícil para manejo en atención prehospitalaria y en áreas críticas del hospital, como salas de cirugía, de emergencia y de cuidado intensivo.

Ablação do flutter atrial típico: estudo prospectivo e randomizado do cateter irrigado fechado versus cateter com eletrodo distal de 8 mm / Ablation of typical atrial flutter: a prospective randomized study of cooled-tip versus 8-mm-tip catheters

OBJETIVOS: Trabalho prospectivo, randomizado para comparar a eficácia e a segurança do cateter irrigado em relação ao cateter com eletrodo distal de 8 mm para ablação com radiofreqüência (RF) do flutter atrial. MÉTODOS: Em 52 pacientes consecutivos referidos para tratamento do flutter atrial típico, a ablação do istmo cavotricuspídeo (Ist-CT) foi realizada com cateter de irrigação fechada (n=26) ou com cateter de eletrodo distal de 8 mm (n=26). Os pulsos de RF foram aplicados ponto a ponto por 60 segundos com potência limitada a 50 w com o cateter irrigado e por controle de temperatura (60°C, 70 w) com cateter de 8 mm. O critério de fim do procedimento foi a obtenção de bloqueio bidirecional do Ist-CT. RESULTADOS: O bloqueio Ist-CT foi obtido em 98,1 por cento dos pacientes. O "crossover" ocorreu em quatro pacientes do grupo com cateter irrigado. Não se encontrou diferença estatística significante em relação aos parâmetros da ablação, tais como tempo total de aplicação de RF (591,1±309,0s vs 486,2±250,8s), duração do procedimento (86,4 ± 23,6 vs 78,1±22,5min) e tempo de fluoroscopia (17,0±6,7 vs 15,4±4,6min) entre os dois grupos. Durante seguimento médio de 10,6 meses, um paciente do grupo irrigado apresentou recorrência do flutter atrial típico. CONCLUSÃO: A ablação do Ist-CT resultou ser efetiva e segura para o controle do flutter atrial com ambas as técnicas empregadas (cateter com eletrodo distal de 8 mm e cateter irrigado). A complexidade técnica do cateter irrigado proporciona menor competitividade.

OBJECTIVES: Both ablation catheters with closed irrigated system and 8mm tip-catheters have been shown to be more effective for typical atrial flutter radiofrequency (RF) ablation when compared to conventional 4 mm tip catheter. Considering the differences in complexity and costs of both systems, a prospective study was designed to compare the efficacy and safety of cooled-tip and 8mm-tip catheters for atrial flutter ablation. METHODS: Fifty-two consecutive patients underwent RF ablation of cavotricupsid isthmus (CTI) for the treatment of typical atrial flutter, using catheter with closed irrigation system (n=26) or 8 mm-tip catheter (n=26). The RF pulses were applied point-by-point for 60 seconds, with power limited at 50 w for the irrigated catheter and by temperature control (60°C / 70 w) for the 8mm catheter. RESULTS: The CTI block was successfully performed in 98.1 percent. Four patients in the irrigated group needed to switch to the other group. There was no significant difference with regard to ablation parameters, such as total time of RF ablation (591.1±309.0s vs 486.2±250.8s), total procedure duration (86.4±23.6 vs 78.1±22.5min) and time of fluoroscopy (17.0±6.7 vs 15.4±4.6min). During follow-up of 10.6 months in average, one patient in the irrigated group had recurrence of typical atrial flutter. CONCLUSION: Efficacy and safety of CTI ablation was comparable between both techniques (irrigated catheter and 8mm-tip catheter). The complexity of irrigated catheter makes it less competitive.

Ablación tumoral por radiofrecuencia / Radiofrequency tumor ablation

Objetivo: La ablación tumoral por radiofrecuencia es un método mínimamente invasivo, utilizado en el tratamiento paliativo con intención curativa de diversos tumores malignos sólidos, primarios o secundarios, en diferentes órganos. El propósito de este trabajo es evaluar nuestra experiencia inicial en la ablación tumoral. Material y métodos: Se seleccionaron 9 pacientes para la ablación de tumores metastáticos: 4 en hígado (2 con metástasis única; un tercero con hepatectomía previa y recaída y otro con lesiones múltiples), 1 riñón, 1 en pulmón, 1 en retroperitoneo y 1 en columna. Con el paciente bajo neuroleptoanalgesia y guiados por ecografía o tomografía computada, se punzó por vía percutánea la lesión tumoral con aguja-electrodo de 15-17 Gauge procediéndose posteriormente al tratamiento con radiofrecuencia. Resultados: No se observaron complicaciones mayores luego de los procedimientos, salvo algunos registros de fiebre o dolor en el sitio de punción. Los pacientes fueron dados de alta luego de 6 24 horas de internación y con controles posteriores las lesiones tratadas mostraron signos de necrosis. Conclusión: Los resultados preliminares demuestran que la ablación por rediofrecuencia de lesiones tumorales sólidas en nuestro medio es un procedimiento intervencionista minimamente invesivo con escasa morbimortalidad y resultados alentadores.