First Ex Vivo Animal Study of a Biological Heart Valve Prosthesis Sensorized with Intravalvular Impedance.

IntraValvular Impedance (IVI) sensing is an innovative concept for monitoring heart valve prostheses after implant. We recently demonstrated IVI sensing feasible in vitro for biological heart valves (BHVs). In this study, for the first time, we investigate ex vivo the IVI sensing applied to a BHV when it is surrounded by biological tissue, similar to a real implant condition. A commercial model of BHV was sensorized with three miniaturized electrodes embedded in the commissures of the valve leaflets and connected to an external impedance measurement unit. To perform ex vivo animal tests, the sensorized BHV was implanted in the aortic position of an explanted porcine heart, which was connected to a cardiac BioSimulator platform. The IVI signal was recorded in different dynamic cardiac conditions reproduced with the BioSimulator, varying the cardiac cycle rate and the stroke volume. For each condition, the maximum percent variation in the IVI signal was evaluated and compared. The IVI signal was also processed to calculate its first derivative (dIVI/dt), which should reflect the rate of the valve leaflets opening/closing. The results demonstrated that the IVI signal is well detectable when the sensorized BHV is surrounded by biological tissue, maintaining the similar increasing/decreasing trend that was found during in vitro experiments. The signal can also be informative on the rate of valve opening/closing, as indicated by the changes in dIVI/dt in different dynamic cardiac conditions.

An engraved surface induces weak adherence and high proliferation of nonadherent cells and microorganisms during culture.

When cells are cultured in a Petri dish, the adherent cells attach to the bottom of the dish; whereas, the nonadherent cells float in the culture medium. It was observed that nonadherent cells could be induced to adherent-like cells when cultured in an engraved plastic dish (biosimulator). The adherence of these cells to the engraved surface could be prevented with inhibitors specific for adhesion. It was also observed that culturing microorganisms of the environment in a biosimulator induced weak adhesion and high proliferation. Analysis of the microbiome using 16S rRNA profiling demonstrated that the biosimulator was more efficient in inducing proliferation of several phyla of microorganisms compared with culture by conventional techniques.

A novel biosimulator based on ex vivo porcine lungs for training in peripheral tissue sampling using endobronchial ultrasonography with a guide sheath.

BACKGROUND: Although radial probe endobronchial ultrasonography (EBUS) with a guide sheath (GS; EBUS-GS) is widely used for sampling peripheral pulmonary lesions (PPLs), a standard training model for EBUS-GS remains to be developed. The purpose of this study was to evaluate the feasibility of a novel pulmonary biosimulator for hands-on training in peripheral tissue sampling using EBUS-GS. METHODS: We established a novel biosimulator for EBUS-GS using porcine lungs. The simulator was equipped with multiple pseudo PPLs that were created using blue agar solution injected through GS inserted in a bronchoscope. A total of 12 voluntary trainees participated in a hands-on training course using the biosimulator. The size of samples acquired using biopsy forceps were compared between initial and post-training biopsies, and trainee satisfaction with the biosimulator and training program were evaluated using a questionnaire. RESULTS: Under the guidance of a trainer, all trainees successfully detected pseudo PPLs using radial probe EBUS before the initial biopsy, and 11 trainees acquired samples from the target lesions during the initial biopsy. Post-training biopsy samples were larger than the initial samples for eight trainees. The results of the questionnaire revealed that all trainees were satisfied with the biosimulator. Moreover, eight trainees who had previously participated in another hands-on EBUS-GS training program involving a synthetic phantom model showed greater satisfaction for the biosimulator. CONCLUSIONS: A hands-on training program using the novel biosimulator assessed in this study could aid clinicians in improving their skills for EBUS-GS and acquiring larger peripheral tissue samples using biopsy forceps inserted through GS.

The dynamic cardiac biosimulator: A method for training physicians in beating-heart mitral valve repair procedures.

OBJECTIVE: Previously, cardiac surgeons and cardiologists learned to operate new clinical devices for the first time in the operating room or catheterization laboratory. We describe a biosimulator that recapitulates normal heart valve physiology with associated real-time hemodynamic performance. METHODS: To highlight the advantages of this simulation platform, transventricular extruded polytetrafluoroethylene artificial chordae were attached to repair flail or prolapsing mitral valve leaflets. Guidance for key repair steps was by 2-dimensional/3-dimensional echocardiography and simultaneous intracardiac videoscopy. RESULTS: Multiple surgeons have assessed the use of this biosimulator during artificial chordae implantations. This simulation platform recapitulates normal and pathologic mitral valve function with associated hemodynamic changes. Clinical situations were replicated in the simulator and echocardiography was used for navigation, followed by videoscopic confirmation. CONCLUSIONS: This beating heart biosimulator reproduces prolapsing mitral leaflet pathology. It may be the ideal platform for surgeon and cardiologist training on many transcatheter and beating heart procedures.

Entrenamiento en un biosimulador y su impacto sobre la destreza en colecistectomía laparoscópica / Biosimulator training and its impact on skill in laparoscopic cholecystectomy

Objetivo: determinar el impacto educacional del entrenamiento en un biosimulador inanimado en términos de efectividad, tiempo y complicaciones, respecto a la colecistectomía laparoscópica. Material y métodos: estudio comparativo, experimental de una cohorte, prospectivo y longitudinal. Tres médicos residentes de primer año de cirugía y un interno de pregrado, fueron entrenados y evaluados en habilidades laparoscópicas elementales mediante el empleo de un biosimulador (maniquí de fibra de vidrio en el que se introducen órganos de animales ex vivo). Los sujetos fueron su propio control: realizaron un procedimiento inicial en el que se determinó tiempo quirúrgico, complicaciones y efectividad. Posteriormente observaron un corto video que mostraba el desarrollo idóneo de la colecistectomía, y en el que se identificaban las desviaciones específicas del desempeño adecuado. Posteriormente cada sujeto realizó 10 procedimientos. Resultados: no existieron diferencias en la evaluación inicial de habilidades elementales. Los individuos completaron todos los procedimientos propuestos. Las disecciones de las estructuras císticas y de la vesícula biliar fueron 61 % más rápidas al finalizar el estudio (p < 0.001); la tasa de complicación fue de 0.67 % (p <0.009). Conclusión: el entrenamiento de habilidades en cirugía endoscópica por medio de un biosimulador inanimado es mejor que el entrenamiento tradicional, ya que disminuye el tiempo quirúrgico y las complicaciones en la sala de operaciones.

OBJECTIVE: We undertook this study to determinate the educational impact of training in an inanimate biosimulator in terms of effectiveness, time and complications in performing laparoscopic cholecystectomy. METHODS: We used a comparative, experimental cohort, prospective and longitudinal. Three first-postgraduate-year residents and one pre-grade internship physician were trained and assessed in basic laparoscopic skills using a biosimulator (fiberglass [quot ]dummy[quot ] where animal organs are introduced ex-vivo). The participants acted as their own control, performing a procedure to determine surgical time, complications and effectiveness. Later they observed a short video demonstrating the suitable development of laparoscopic cholecystectomy. The video defined the specific deviations from the ideal cholecystectomy, which were considered as errors. Every procedure was videotaped, beginning with the careful dissection of cystic structures and clipping them, continuing with the dissection of the gallbladder from the liver with the standardized method. Each participant performed ten procedures. RESULTS: There were no differences in baseline assessment of basic skills. All participants completed all proposed procedures. Surgical time was 61% faster at the end of the study (p<0.001), as well as demonstrating a lower rate of complications of 0.67% (p<0.009). CONCLUSIONS: Skills training in endoscopic surgery by means of an inanimate biosimulator is superior to traditional training because it decreases surgical time and surgical complications without ethical considerations and the effect of a learning curve in the operating room.