RESUMO
BACKGROUND: Advanced bipolar and ultrasonic energy have demonstrated reduction of operating time and blood loss in thyroidectomy. However, these devices generate heat and thermal dispersion that may damage adjacent structures such as the recurrent laryngeal nerve (RLN). This study was designed to evaluate the safety profile of the Harmonic Focus+® (HF+) device through the evaluation of thermal injury to the RLN using different algorithms of distance and time with state of the art technology. METHODS: 25 Vietnamese pigs underwent activation of HF+ in the proximity of their RLN. They were divided into 4 groups according to activation distance (3 mm, 2 mm, 1 mm and on the RLN). Time of activation, time between tones of the ultrasonic generator, changes in the electromyographic signal using continuous nerve neuromonitoring, vocal fold mobility assessed by direct laryngoscopy and histological thermal damaged were evaluated. RESULTS: None of the pigs had loss of signal in the electromyography during the procedure; only one pig had isolated transient decrease in amplitude and one increase in latency. One pig had transient vocal fold paresis in the group with activation on the nerve. Evaluation of the nerves by histology and immunohistochemistry did not show significant changes attributed to thermal injury. CONCLUSIONS: The use of ultrasonic energy close to the RLN is safe, provided that activation time does not exceed the necessary time to safely transect the tissue.
Assuntos
Hemostasia Cirúrgica/instrumentação , Complicações Intraoperatórias/prevenção & controle , Traumatismos do Nervo Laríngeo Recorrente/prevenção & controle , Procedimentos Cirúrgicos Ultrassônicos/instrumentação , Animais , Eletromiografia , Hemostasia Cirúrgica/efeitos adversos , Temperatura Alta/efeitos adversos , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/patologia , Monitorização Intraoperatória , Traumatismos do Nervo Laríngeo Recorrente/diagnóstico , Traumatismos do Nervo Laríngeo Recorrente/etiologia , Traumatismos do Nervo Laríngeo Recorrente/patologia , Suínos , Tireoidectomia/efeitos adversos , Tireoidectomia/instrumentação , Tireoidectomia/métodos , Fatores de Tempo , Procedimentos Cirúrgicos Ultrassônicos/efeitos adversosRESUMO
Laparoscopic cholecystectomy (LC) is the gold standard technique for the treatment of gallbladder disease. However, in some cases, conversion to open surgery is still necessary. Identification of patients with high risk of conversion is of great importance to prepare the surgical scenario and to anticipate the convalescence. The objective of this study is to identify the factors that may predict a conversion to an open procedure. A total of 1386 LC were performed in Dr. Manuel Gea González General Hospital, from January 2009 to May 2013. A retrospective analysis of 41 parameters in these patients was performed, including demographic variables, clinical history, laboratory studies, ultrasound results and intraoperative findings. Subsequently, a multivariate logistic regression analysis was used to determine the predictive variables for conversion. Fourteen patients required conversion (1%). The multivariate analysis revealed that the factor that was most associated with conversion was emergency surgery (OR 4.9, CI 95% 2.3-2.4), as well as dilatation > 6 mm of the common bile duct in ultrasound (OR 1.8, CI 95% 1.1-1.7), hepatomegaly (OR 1.3, CI 95% 0.3-4.9), diagnosis of chronic cholecystitis associated to previous biliary colics (OR 2.8, CI 95% 1.0-21) and elevated alanine aminotransaminase (OR 1.2, CI 95% 1.0-2.1). Patients with acute symptoms, with dilatation of the bile duct, cholestasis history and hepatomegaly have a higher risk of a conversion surgery. These factors may warn both the patient and the surgeon for a complex surgery and possible complications.