Safety of an esophageal deviator for atrial fibrillation catheter ablation.

Background: Esophageal thermal injury is a complication of atrial fibrillation (AF) ablation, and it can be avoided by esophageal deviation during left atrial posterior wall radiofrequency catheter ablation. Objective: This study aimed to evaluate the safety of a nitinol-based mechanical esophageal displacement device (MEDD) and its performance. Methods: This preclinical safety study was conducted on 20 pigs, with 10 undergoing radiofrequency AF ablation using the MEDD and 10 serving as a control group under anticoagulation but without radiofrequency application. Esophageal traumatic injuries were classified from 0 to 4 and were grouped as absent (grade 0), minor (grade 1 or 2), moderate (grade 3), or major risk lesions (grade 4) by anatomopathological study. Grades 1 and 2 were considered acceptable. Fluoroscopy was used to measure displacement. Results: Five (25%) pigs developed traumatic lesions, 4 with grade 1 and 1 with grade 2 (2-mm superficial ulcer). There was no difference in lesion occurrence between the radiofrequency and control groups (30% and 20%, respectively; P = .43). Under rightward displacement, the right edge moved 23.9 (interquartile range [IQR] 21.3-26.3) mm and the left edge moved 16.3 (IQR 13.8-18.4) mm (P < .001) from baseline. Under leftward displacement, the right edge moved 13.5 (IQR 10.9-15.3) mm and the left edge moved 16.5 (IQR 12.3-18.5) mm (P = .07). A perforation to the pharyngeal diverticulum occurred in 1 pig, related to an accidental extubation. Conclusion: In pigs, the MEDD demonstrated safety in relation to esophageal tissue, and successful deviation. Esophageal traumatic injuries were acceptable, but improper manipulation led to pharyngeal lesion.

Comparative study of strategies to prevent esophageal and periesophageal injury during atrial fibrillation ablation.

OBJECTIVE: To compare the prevalence of esophageal and periesophageal thermal injury in patients undergoing radiofrequency (RF) atrial fibrillation (AF) ablation using 8 mm tip catheters during three different esophageal protection strategies. METHODS: Forty-five consecutive patients with paroxysmal or persistent AF underwent first ablation procedure, besides esophagogastroduodenoscopy (EGD) combined with radial endosonography (EUS) performed before and after the pulmonary vein (PV) isolation. Before the procedure, patients were randomly assigned to one of three esophageal lesion protection strategies: group I-without any protective or monitoring dispositive and limiting RF applications to 30 W for 20 seconds, in left atrium posterior wall (LAPW); group II-power and time of RF delivery, up to 50 W for 20 seconds at LAPW, limited by esophageal temperature monitoring; group III-applications of RF in LAPW with fixed power application of 50 W for 20 seconds during continuous esophageal cooling. RESULTS: Baseline characteristics of patients were similar in all groups. The four PVs were isolated in 14 (93.3%), 13 (86.7%), and 15 (100%) patients, respectively in groups I, II, and III. The mean RF power was significantly higher (P < .001) in the posterior side of PVs in group III. Post-AF ablation EGD and EUS revealed two esophageal wall ulcerations and two periesophageal mediastinal edemas only in the esophageal cooling group (P = .008). CONCLUSION: Esophageal cooling balloon strategy resulted in a higher RF power energy delivery when ablating at the LA posterior wall, using 8 mm nonirrigated tip catheters under temperature mode control. Despite that, patients presented a relatively low incidence of esophageal and periesophaeal injuries.

Prótese para toracostomia: desenvolvimento e utilizaçäo clínica / Prosthesis for toracostomy: development and clinical utilization

O objetivo deste trabalho é o desenvolvimento de uma prótese em silicone para ser utilizada em toracostomia, à Eloesser modificado no tratamento dos empiemas crônicos, sobretudo nos empiemas pós-pneumectomia. Esse sistema deixa um aspecto estético bastante desagradável ao paciente, além de representar um ato cirúrgico relativamente complexo para a função a que se propõe. A proposição consiste de um tubo de silicone de 25 mm de diâmetro, corrugado, e com anteparo interno e externo, para evitar migrações que pode ser colocada através de uma incisão de 30 a 40 mm e ressecção segmentar de apenas uma costela, diminuindo o trauma cirúrgico, como também as seqüelas estéticas na parede torácica, enquanto mantém adequada e contínua drenagem do espaço pleural. Até a presente data, 13 pacientes foram submetidos à toracostomia utilizando a prótese desenvolvida, com tempo de acompanhamento entre 14 a 305 dias. Os resultados são satisfatórios e sugerem que a utilização da prótese apresenta vantagens quando comparadas aos métodos tradicionais.

Abstract - This paper presents the design and construction of a toracostomy silicone prosthesis. Its main utilization is in Clagett's and modified Eloesser toracostomies and for the treatment of chronic and post-pneúmonectomy empyemas. The new prosthesis designed consists of a silicone tube (25 mm diameter) corrugated and with one internal and one externa! flange to avoid migration. It can be placed through a 30 to 40 mm incision and resection of a segment of solely one rib, minimizing surgical trauma and resulting in a esthetically improved aspect, while maintaining adequate and continuous draining of the pleural space. Hitherto, the prosthesis was utilized in 13 patients subjected to toracostomy with a follow up period of 14 to 305 days. The results obtained suggest that its utilization presents many advantages in comparison to the traditional method utilized