Osteogenic-angiogenic coupled response of cobalt-containing mesoporous bioactive glasses in vivo.

The incorporation of cobalt ions into the composition of bioactive glasses has emerged as a strategy of interest for bone regeneration purposes. In the present work, we have designed a set of bioactive mesoporous glasses SiO2-CaO-P2O5-CoO (Co-MBGs) with different amounts of cobalt. The physicochemical changes introduced by the Co2+ ion, the in vitro effects of Co-MBGs on preosteoblasts and endothelial cells and their in vivo behaviour using them as bone grafts in a sheep model were studied. The results show that Co2+ ions neither destroy mesoporous ordering nor inhibit in vitro bioactive behaviour, exerting a dual role as network former and modifier for CoO concentrations above 3 % mol. On the other hand, the activity of Co-MBGs on MC3T3-E1 preosteoblasts and HUVEC vascular endothelial cells is dependent on the concentration of CoO present in the glass. For low Co-MBGs concentrations (1mg/ml) cell viability is not affected, while the expression of osteogenic (ALP, RUNX2 and OC) and angiogenic (VEGF) genes is stimulated. For Co-MBGs concentration of 5 mg/ml, cell viability decreases as a function of the CoO content. In vivo studies show that the incorporation of Co2+ ions to the MBGs improves the bone regeneration activity of these materials, despite the deleterious effect that this ion has on bone-forming cells for any of the Co-MBG compositions studied. This contradictory effect is explained by the marked increase in angiogenesis that takes place inside the bone defect, leading to an angiogenesis-osteogenesis coupling that compensates for the partial decrease in osteoblast cells. STATEMENT OF SIGNIFICANCE: The development of new bone grafts implies to address the need for osteogenesis-angiogenesis coupling that allows bone regeneration with viable tissue in the long term. In this sense the incorporation of cobalt ions into the composition of bioactive glasses has emerged as a strategy of great interest in this field. Due to the potential cytotoxic effect of cobalt ions, there is an important controversy regarding the suitability of their incorporation in bone grafts. In this work, we address this controversy after the implantation of cobalt-doped mesoporous bioactive glasses in a sheep model. The incorporation of cobalt ions in bioactive glasses improves the bone regeneration ability of these bone grafts, due to enhancement of the angiogenesis-osteogenesis coupling.

Injectable mesoporous bioactive nanoparticles regenerate bone tissue under osteoporosis conditions.

The osteogenic capability of mesoporous bioactive nanoparticles (MBNPs) in the SiO2CaO system has been assessed in vivo using an osteoporotic rabbit model. MBNPs have been prepared using a double template method, resulting in spherical nanoparticles with a porous core-shell structure that has a high surface area and the ability to incorporate the anti-osteoporotic drug ipriflavone. In vitro expression of the pro-inflammatory genes NF-κB1, IL-6, TNF-α, P38 and NOS2 in RAW-264.7 macrophages, indicates that these nanoparticles do not show adverse inflammatory effects. An injectable system has been prepared by suspending MBNPs in a hyaluronic acid-based hydrogel, which has been injected intraosseously into cavitary bone defects in osteoporotic rabbits. The histological analyses evidenced that MBNPs promote bone regeneration with a moderate inflammatory response. The incorporation of ipriflavone into these nanoparticles resulted in a higher presence of osteoblasts and enhanced angiogenesis at the defect site, but without showing significant differences in terms of new bone formation. STATEMENT OF SIGNIFICANCE: Mesoporous bioactive glass nanoparticles have emerged as one of the most interesting materials in the field of bone regeneration therapies. For the first time, injectable mesoporous bioactive nanoparticles have been tested in vivo using an osteoporotic animal model. Our findings evidence that MBG nanoparticles can be loaded with an antiosteoporotic drug, ipriflavone, and incorporated in hyaluronic acid to make up an injectable hydrogel. The incorporation of MBG nanoparticles promotes bone regeneration even under osteoporotic conditions, whereas the presence of IP enhances angiogenesis as well as the presence of osteoblast cells lining in the newly formed bone. The injectable device presented in this work opens new possibilities for the intraosseous treatment of osteoporotic bone using minimally invasive surgery.

Silicon substituted hydroxyapatite/VEGF scaffolds stimulate bone regeneration in osteoporotic sheep.

Silicon-substituted hydroxyapatite (SiHA) macroporous scaffolds have been prepared by robocasting. In order to optimize their bone regeneration properties, we have manufactured these scaffolds presenting different microstructures: nanocrystalline and crystalline. Moreover, their surfaces have been decorated with vascular endothelial growth factor (VEGF) to evaluate the potential coupling between vascularization and bone regeneration. In vitro cell culture tests evidence that nanocrystalline SiHA hinders pre-osteblast proliferation, whereas the presence of VEGF enhances the biological functions of both endothelial cells and pre-osteoblasts. The bone regeneration capability has been evaluated using an osteoporotic sheep model. In vivo observations strongly correlate with in vitro cell culture tests. Those scaffolds made of nanocrystalline SiHA were colonized by fibrous tissue, promoted inflammatory response and fostered osteoclast recruitment. These observations discard nanocystalline SiHA as a suitable material for bone regeneration purposes. On the contrary, those scaffolds made of crystalline SiHA and decorated with VEGF exhibited bone regeneration properties, with high ossification degree, thicker trabeculae and higher presence of osteoblasts and blood vessels. Considering these results, macroporous scaffolds made of SiHA and decorated with VEGF are suitable bone grafts for regeneration purposes, even in adverse pathological scenarios such as osteoporosis. STATEMENT OF SIGNIFICANCE: For the first time, the in vivo behavior of scaffolds made of silicon substituted hydroxyapatites (SiHA) has been evaluated under osteoporosis conditions. In order to optimize the bone regeneration properties of these bioceramics, 3D macroporous scaffolds have been manufactured by robocasting and implanted in osteoporotic sheep. Our experimental design shed light on the important issue of the biological response of nano-sized bioceramics vs highly crystalline bioceramics, as well as on the importance of coupling vascularization and bone growth processes by decorating SiHA scaffolds with vascular endothelial growth factor.

Validación de un nuevo modelo de simulación inorgánica para la anastomosis uretrovesical laparoscópica / Validation of a new artificial model for simulated training of a laparoscopic vesicourethral anastomosis

Objetivo: El objetivo de este estudio es demostrar la validez de un modelo inorgánico de bajo coste para el aprendizaje y entrenamiento de la anastomosis uretrovesical laparoscópica. Materiales y métodos: En este estudio participaron alumnos que asistieron a alguna de las ediciones de los cursos monográficos sobre prostatectomía radical laparoscópica (PRL) celebrados durante el periodo de 2015 a 2017. Estos participantes se dividieron en 2 grupos de acuerdo con su experiencia previa en cirugía laparoscópica (CL). Las tareas que realizaron sobre el simulador inorgánico fueron la resección de la próstata, "tarea 1" y la anastomosis uretrovesical, "tarea 2". Una vez realizados estos ejercicios, los participantes del estudio completaron un cuestionario anónimo donde se recogieron sus datos demográficos y su nivel de experiencia en CL. Además, los asistentes realizaron una valoración de la capacidad didáctica del órgano sintético empleado, evaluando su utilidad como herramienta para la formación específica de PRL. Para demostrar la validación aparente y de contenidos los participantes mostraron su opinión acerca de la textura, la consistencia, la morfología y la similitud del órgano con el paciente real. La valoración se realizó según una escala de Likert de 5 puntos. Resultados: Los alumnos se distribuyeron en 2 grupos: 10 expertos (grupo E) y 12 noveles (grupo N). La única diferencia significativa entre las puntuación de noveles y de expertos fue respecto a la inclusión de esta herramienta en los programas de formación (grupo E = 5 puntos frente al grupo N = 4,4 ± 0,59, p = 0,024). Los expertos calificaron todas las cuestiones con mayores puntaciones que los noveles. En cuanto a la valoración general del modelo inorgánico, los participantes noveles dieron una calificación media de 8,00±0,91 puntos sobre 10, siendo superada por la valoración de los participantes del grupo de expertos, que dieron una puntuación media de 9,4 ± 0,51. Conclusión: Este modelo inorgánico ha demostrado poseer validez aparente, de contenidos y constructiva, además de ser una herramienta didáctica ideal para el aprendizaje y el entrenamiento de la resección prostática y de la anastomosis uretrovesical laparoscópica

Objective: The aim of this study is to prove the effectiveness of a low cost, artificial model for training of a laparoscopic urethrovesical anastomosis. Materials and methods: This study included urologists who attended specialised courses on laparoscopic radical prostatectomy (LRP) held during the period 2015 to 2017. They were divided into 2 groups according to their previous experience in laparoscopic surgery. The tasks performed on the artificial simulator were prostate resection, "task 1", and urethrovesical anastomosis, "task 2". Once these exercises were completed, the study participants filled in an anonymous questionnaire regarding their demographic data and experience level in laparoscopic surgery (LS). In addition, they gave their opinions about the didactic capacity of the artificial organ and evaluated its usefulness as a tool for LRP training. To demonstrate face and content validity, the participants judged the texture, consistency, morphology and evaluated its similarity to the real organ. The assessment was made with a five-point Likert scale. Results: The students were divided into 2 groups: 10 experts (Group E) and 12 novices (Group N). The only significant difference between the scores of novices and experts was regarding the inclusion of this tool in the training programs (Group E = 5 points versus group N = 4.4 ± 0.59, P = .024). The experts' group rated all the items with higher scores than the novices’ one. Regarding the general assessment of the simulation model, the novice participants gave an average score of 8.00 ± 0.91 points out of 10, while the experts’ group granted higher scores of 9.4 ± 0,51. Conclusion: This artificial model has shown to have an elevated face, content and construct validity, as well being an optimal didactic tool for training in the techniques of prostate resection and laparoscopic urethrovesical anastomosis

Validation of a new artificial model for simulated training of a laparoscopic vesicourethral anastomosis. / Validación de un nuevo modelo de simulación inorgánica para la anastomosis uretrovesical laparoscópica.

OBJECTIVE: The aim of this study is to prove the effectiveness of a low cost, artificial model for training of a laparoscopic urethrovesical anastomosis. MATERIALS AND METHODS: This study included urologists who attended specialised courses on laparoscopic radical prostatectomy (LRP) held during the period 2015 to 2017. They were divided into 2 groups according to their previous experience in laparoscopic surgery. The tasks performed on the artificial simulator were prostate resection, "task 1", and urethrovesical anastomosis, "task 2". Once these exercises were completed, the study participants filled in an anonymous questionnaire regarding their demographic data and experience level in laparoscopic surgery (LS). In addition, they gave their opinions about the didactic capacity of the artificial organ and evaluated its usefulness as a tool for LRP training. To demonstrate face and content validity, the participants judged the texture, consistency, morphology and evaluated its similarity to the real organ. The assessment was made with a five-point Likert scale. RESULTS: The students were divided into 2groups: 10 experts (Group E) and 12 novices (Group N). The only significant difference between the scores of novices and experts was regarding the inclusion of this tool in the training programs (Group E=5 points versus group N=4.4±0.59, P=.024). The experts' group rated all the items with higher scores than the novices' one. Regarding the general assessment of the simulation model, the novice participants gave an average score of 8.00±0.91 points out of 10, while the experts' group granted higher scores of 9.4±0,51. CONCLUSION: This artificial model has shown to have an elevated face, content and construct validity, as well being an optimal didactic tool for training in the techniques of prostate resection and laparoscopic urethrovesical anastomosis.

Mesoporous bioactive glass/ɛ-polycaprolactone scaffolds promote bone regeneration in osteoporotic sheep.

Macroporous scaffolds made of a SiO2-CaO-P2O5 mesoporous bioactive glass (MBG) and ɛ-polycaprolactone (PCL) have been prepared by robocasting. These scaffolds showed an excellent in vitro biocompatibility in contact with osteoblast like cells (Saos 2) and osteoclasts derived from RAW 264.7 macrophages. In vivo studies were carried out by implantation into cavitary defects drilled in osteoporotic sheep. The scaffolds evidenced excellent bone regeneration properties, promoting new bone formation at both the peripheral and the inner parts of the scaffolds, thick trabeculae, high vascularization and high presence of osteoblasts and osteoclasts. In order to evaluate the effects of the local release of an antiosteoporotic drug, 1% (%wt) of zoledronic acid was incorporated to the scaffolds. The scaffolds loaded with zoledronic acid induced apoptosis in Saos 2 cells, impeded osteoclast differentiation in a time dependent manner and inhibited bone healing, promoting an intense inflammatory response in osteoporotic sheep. STATEMENT OF SIGNIFICANCE: In addition to an increase in bone fragility and susceptibility to fracture, osteoporosis also hinders the clinical success of endosseous implants and grafting materials for the treatment of bone defects. For the first time, macroporous scaffolds made of mesoporous bioactive glass and ε-caprolactone have been evaluated in a sheep model that mimics the osteoporosis conditions in humans. These implants fostered bone regeneration, promoting new bone formation at both the peripheral and the inner parts of the scaffolds, showing thick trabeculae and a high vascularization degree. Our results indicate that macroporous structures containing highly bioactive mesoporous glasses could be excellent candidates for the regenerative treatment of bone defects in osteoporotic patients.

Synergistic effect of Si-hydroxyapatite coating and VEGF adsorption on Ti6Al4V-ELI scaffolds for bone regeneration in an osteoporotic bone environment.

The osteogenic and angiogenic responses to metal macroporous scaffolds coated with silicon substituted hydroxyapatite (SiHA) and decorated with vascular endothelial growth factor (VEGF) have been evaluated in vitro and in vivo. Ti6Al4V-ELI scaffolds were prepared by electron beam melting and subsequently coated with Ca10(PO4)5.6(SiO4)0.4(OH)1.6 following a dip coating method. In vitro studies demonstrated that SiHA stimulates the proliferation of MC3T3-E1 pre-osteoblastic cells, whereas the adsorption of VEGF stimulates the proliferation of EC2 mature endothelial cells. In vivo studies were carried out in an osteoporotic sheep model, evidencing that only the simultaneous presence of both components led to a significant increase of new tissue formation in osteoporotic bone. STATEMENT OF SIGNIFICANCE: Reconstruction of bones after severe trauma or tumors extirpation is one of the most challenging tasks in the field of orthopedic surgery. This scenario is even more complicated in the case of osteoporotic patients, since their bone regeneration capability is decreased. In this work we present a porous implant that promotes bone regeneration even in osteoporotic bone. By coating the implant with osteogenic bioceramics such as silicon substituted hydroxyapatite and subsequent adsorption of vascular endothelial growth factor, these implants stimulate the bone ingrowth when they are implanted in osteoporotic sheep.

Validación inicial de un programa de formación enfocado a la nefrectomía radical laparoscópica / Initial validation of a training program focused on laparoscopic radical nephrectomy

Objetivo: Evaluar un modelo de formación enfocado a la nefrectomía laparoscópica. Material y métodos: Participaron en el estudio 16 residentes, quienes realizaron un programa formativo con una sesión teórica (1 h) y práctica en simulador (7 h) y modelo animal (13 h). La primera y última nefrectomía experimental fue evaluada mediante el tiempo y la escala global Objective and Structured Assessment of Technical Skills(OSATS). Antes y después del curso realizaron 3 ejercicios en el simulador de realidad virtual LAPMentor: 1) coordinación ojo-mano; 2) coordinación mano-mano; y 3) transferencia de objetos, registrando las métricas de tiempo y movimiento. Todos los participantes rellenaron un cuestionario sobre los componentes formativos en una escala del 1 al 5. Resultados: Los participantes realizaron la última nefrectomía más rápido (p < 0,001) y con mayor puntuación OSATS (p < 0,001). Después del curso realizaron los ejercicios en LAPMentor más rápido (p < 0,05). El número de movimientos disminuyó en todos los ejercicios: 1) p < 0,001; 2) p < 0,05; y 3) p < 0,05, y la distancia recorrida en los ejercicios 1 (p < 0,05) y 2 (p < 0,05). La velocidad de movimientos aumentó en los ejercicios 2 (p < 0,001) y 3 (p < 0,001). En el cuestionario las preguntas con la mayor puntuación fueron la utilidad del entrenamiento en animal y la necesidad del mismo antes de la práctica de laparoscopia clínica (4,92 ± 0,28). Conclusiones: La combinación de simulación física y entrenamiento en animal constituye un modelo de formación efectivo para la mejora de habilidades básicas y avanzadas para la nefrectomía laparoscópica. El componente preferido por los residentes fue el modelo animal

Objective: To assess a training model focused on laparoscopic nephrectomy. Material and methods: 16 residents participated in the study, who attended a training program with a theoretical session (1 hour) and a dry (7 hours) and a wet lab (13 hours). During animal training, the first and last nephrectomies were assessed through the completion time and the global rating scale "Objective and Structured Assessment of Technical Skills" (OSATS). Before and after the course, they performed 3 tasks on the virtual reality simulator LAPMentor (1) eye-hand coordination; 2) hand-hand coordination; and 3) transference of objects), registering time and movement metrics. All participants completed a questionnaire related to the training components on a 5-point rating scale. Results: The participants performed the last nephrectomy faster (P < .001) and with higher OSATS scores (P < .001). After the course, they completed the LAPMentor tasks faster (P < .05). The number of movements decreased in all tasks (1) P < .001, 2) P < .05, and 3) P < .05), and the path length in tasks 1 (P < .05) and 2 (P < .05). The movement speeds increased in tasks 2 (P < .001) and 3 (P < .001). With regards to the questionnaire, the usefulness of the animal training and the necessity of training on them prior to their laparoscopic clinical practice were the questions with the highest score (4.92 ± .28). Conclusions: The combination of physical simulation and animal training constitute an effective training model for improving basic and advanced skills for laparoscopic nephrectomy. The component preferred by the urology residents was the animal training

Initial validation of a training program focused on laparoscopic radical nephrectomy. / Validación inicial de un programa de formación enfocado a la nefrectomía radical laparoscópica.

OBJECTIVE: To assess a training model focused on laparoscopic nephrectomy. MATERIAL AND METHODS: 16 residents participated in the study, who attended a training program with a theoretical session (1hour) and a dry (7hours) and a wet lab (13hours). During animal training, the first and last nephrectomies were assessed through the completion time and the global rating scale "Objective and Structured Assessment of Technical Skills" (OSATS). Before and after the course, they performed 3 tasks on the virtual reality simulator LAPMentor (1) eye-hand coordination; 2) hand-hand coordination; and 3) transference of objects), registering time and movement metrics. All participants completed a questionnaire related to the training components on a 5-point rating scale. RESULTS: The participants performed the last nephrectomy faster (P<.001) and with higher OSATS scores (P<.001). After the course, they completed the LAPMentor tasks faster (P<.05). The number of movements decreased in all tasks (1) P<.001, 2) P<.05, and 3) P<.05), and the path length in tasks 1 (P<.05) and 2 (P<.05). The movement speeds increased in tasks 2 (P<.001) and 3 (P<.001). With regards to the questionnaire, the usefulness of the animal training and the necessity of training on them prior to their laparoscopic clinical practice were the questions with the highest score (4.92±.28). CONCLUSIONS: The combination of physical simulation and animal training constitute an effective training model for improving basic and advanced skills for laparoscopic nephrectomy. The component preferred by the urology residents was the animal training.

Preliminary application of a single-port access technique for laparoscopic ovariohysterectomy in dogs.

Laparoscopic ovariohysterectomy using single-portal access was performed in nine selected owned dogs admitted for elective ovariohysterectomy and the surgical technique and outcomes were detailed. A multiport device (SILS Port, Covidien, USA) was placed at the umbilical area through a single 3 cm incision. Three cannulae were introduced in the multiport device through the access channels and laparoscopic ovariohysterectomy was performed using a 5-mm sealing device, a 5-mm articulating grasper and a 5-mm 30° laparoscope. The mean total operative time was 52.66±15.20 minutes and the mean skin incision during surgery was 3.09±0.20 cm. Of the nine cases examined, in the one with an ovarian tumour, the technique was converted to multiport laparoscopy introducing an additional 5-mm trocar. No surgical complications were encountered and intraoperative blood loss was minimum in all animals. Clashing of the instruments and reduced triangulation were the main limitations of this technique. The combination of articulated and straight instruments facilitated triangulation towards the surgical field and dissection capability. One month after surgery a complete wound healing was observed in all animals. The present data showed that ovariohysterectomy performed with a single-port access is technically feasible in dogs. The unique abdominal incision minimises the abdominal trauma with good cosmetic results.

Objective analysis of surgeons' ergonomy during laparoendoscopic single-site surgery through the use of surface electromyography and a motion capture data glove.

BACKGROUND: Adding to the ergonomic inconveniences already presented by traditional laparoscopy (LAP), laparoendoscopic single-site (LESS) surgery has been found to entail other more specific problems, including greater reduction in movement freedom, in-line vision with loss of triangulation, and greater proximity of instruments. The objective of this study was to evaluate surgeons' ergonomy during LESS surgery, through the study of muscular activity, wrist angle, and hand movements, and compare it with conventional laparoscopy. METHODS: The study group was composed by 14 experienced laparoscopic surgeons, all right-handed. Each one performed dissection tasks on a physical simulator through LAP and LESS approaches. For LAP, straight laparoscopic scissors and dissector were used, whilst for LESS articulating tip scissors and dissector were chosen. During both tasks, muscular activity of biceps brachii, triceps brachii, forearm flexors and extensors, and trapezius muscles was registered through surface electromyography. Simultaneously right-hand movements and wrist angles were obtained through a motion capture data glove (CyberGlove(®)), which allowed for the use of a modified RULA test applied to the recorded angles with subsequent establishment of risk levels for the wrist joint. RESULTS: Muscular activity for trapezius (LAP 6.94 ± 4.12 vs. LESS 11.32 ± 4.68; p ≤ 0.05) and forearm extensor muscles (LAP 9.2 ± 2.45 vs. LESS 37.07 ≤ 16.05; p ≤ 0.001) was significantly lower in conventional laparoscopy compared with LESS approach. No statistical significance was obtained between the different sensors, except in 3 of the 11 analyzed CyberGlove(®) sensors. The modified RULA test showed a score of 3 for laparoscopy (unacceptable), whereas for LESS a score of 2 was obtained (acceptable), with statistically significant differences between them (p ≤ 0.05). CONCLUSIONS: The LESS approach entails greater level of muscular activity in the trapezius and forearm extensor muscles, but we have found evidences of a better wrist position during LESS compared with traditional laparoscopy.

Diseño y validación de un programa formativo en cirugía laparoscópica pediátrica y neonatal / Design and validation of a training model on paediatric and neonatal surgery

Presentamos nuestra experiencia en la fase de diseño y desarrollo de un programa formativo en cirugía laparoscópica pediátrica y neonatal y su validación subjetiva por parte de los asistentes. Los datos presentados en este trabajo han sido extraídos de las cinco ediciones del Curso de Cirugía Laparoscópica Pediátrica y Neonatal, desarrolladas en nuestro Centro, a las que han asistido 54 cirujanos. El modelo formativo, de 21 horas de duración, comienza con el conocimiento de aspectos generales de la ergonomía y del instrumental, tras lo cual los alumnos adquieren destrezas básicas mediante la práctica en simulador físico. Posteriormente, se acometen diversas técnicas en modelo animal, siempre asistidos por profesorado experto. Al término de las actividades, los asistentes evaluaron diversos aspectos didácticos y organizativos del programa formativo. Hemos obtenido una valoración muy positiva en los diferentes temas y técnicas del programa (≥ 9 puntos sobre 10). El 78,5% de los asistentes estuvo de acuerdo con la duración del curso, mientras que un 21,5% consideró que debería ser de mayor duración. El 79,1% se vio capacitado para realizar en pacientes las técnicas desarrolladas. El modelo formativo presentado ha demostrado poseer una muy alta valoración, aumentando la confianza de los asistentes para realizar las técnicas planteadas en la práctica clínica (AU)

We present our experience in the design and development of a training program in paediatric and neonatal laparoscopic surgery, and the determination of face validity by the attendants. Data included in the present study was obtained from five consecutive editions of our Neonatal and Paediatric Laparoscopic Surgery Course. Our training model, with a total duration of 21 hours, begins with acquisition of knowledge in ergonomics and instrument concepts, after which the attendants develop basic laparoscopic dexterity through the performance of hands-on physical simulator tasks. During the second and third days of the course, surgeons undertook various surgical techniques hands-on animal model. At the end of the training program, a subjective evaluation questionnaire was handed out to the attendants, in which different didactic and organizational aspects were considered. We obtained a highly positive score on all questions concerning the different topics and techniques included in the training program (≥9 points over 10). 78,5% of the 54 attendants was in accordance with the course total duration, whilst 21,5% considered that it should be of longer duration. Regarding abilities’ self assessment, 79,1% considered themselves capacitated to perform trained procedures on live patients. The presented training model has obtained a very positive valuation score, leading to an increase in the attendants’ self confidence in the application of learned techniques to their clinical practice (AU)

[Design and validation of a training model on paediatric and neonatal surgery]. / Diseño y validación de un programa formativo en cirugía laparoscópica pediátrica y neonatal.

We present our experience in the design and development of a training program in paediatric and neonatal laparoscopic surgery, and the determination of face validity by the attendants. Data included in the present study was obtained from five consecutive editions of our Neonatal and Paediatric Laparoscopic Surgery Course. Our training model, with a total duration of 21 hours, begins with acquisition of knowledge in ergonomics and instrument concepts, after which the attendants develop basic laparoscopic dexterity through the performance of hands-on physical simulator tasks. During the second and third days of the course, surgeons undertook various surgical techniques hands-on animal model. At the end of the training program, a subjective evaluation questionnaire was handed out to the attendants, in which different didactic and organizational aspects were considered. We obtained a highly positive score on all questions concerning the different topics and techniques included in the training program (> or = 9 points over 10). 78,5% of the 54 attendants was in accordance with the course total duration, whilst 21,5% considered that it should be of longer duration. Regarding abilities' self assessment, 79,1% considered themselves capacitated to perform trained procedures on live patients. The presented training model has obtained a very positive valuation score, leading to an increase in the attendants' self confidence in the application of learned techniques to their clinical practice.

Technical feasibility of laparoscopic Finney pyloroplasty examined in a canine model.

The efficacy of laparoscopic surgery in the treatment of chronic duodenal ulcer has been demonstrated using minimally invasive approaches. This study aimed to evaluate the technical feasibility of laparoscopic Finney pyloroplasty in six dogs. Under laparoscopic guidance, the anastomosis was created using mechanical devices (n = 3) and combining a linear stapler device and intracorporeal suturing (n = 3). The operative time and complications were recorded. Evaluation of the anastomosis included studies of intraoperative and postoperative endoscopy and ultrasonography as well as the complete gastric emptying time. The animals were killed 4 weeks after surgery. Measurement of luminal diameter, amount of adhesion formation, degree of healing, and inflammation or fibrosis were evaluated in the postmortem studies. The operation was successfully completed for all the animals. No intraoperative or postoperative complications were observed. Gastric emptying was significantly enhanced in the postoperative period, as compared with the preoperative results. After 1 month, there was no evidence of anastomotic leak dehiscence at the gastroduodenal anastomosis. Luminal diameter was increased, and no abnormal findings were encountered during the postmortem abdominal exploration. The technical feasibility of performing a safe laparoscopic pyloroplasty in a dog model was demonstrated in this study.

The cybergut. An experimental study on permanent microchip neuromodulation for control of gut function.

UNLABELLED: Acute electrical stimulation of vagal nerve changes gut motility, secretion as well as absorption, and it may have effect on food intake and satiety regulation. The aim of the study was to evaluate the effect of permanent microchip mediated neuromodulation (McNm) of vagal afferent activity on GI function and body mass in the experimental model. MATERIAL AND METHODS: Two-steps study was performed. In the first step (evaluation of food intake) 16 rabbits were divided in two groups, 8 animals each. Group A was subjected to microchip mediated neuromodulation (McNm), and control group B was sham operated. In both groups laparotomy and vagal exploration were performed. In the second step pathomechanism of Mc action was analysed in fourteen Wistar rats divided in two groups (C and D), 7 animals each. Group C was subjected to Mc implantation and gastrostomy placement and group D (controls) to gastrostomy placement alone. RESULTS: Food intake and body mass significantly decreased in group A after Mc implantation compared with the preoperative period and control group B. No differences were found in the frequency of gastric contractions between groups C and D, however, their amplitude was significantly stronger in group C. Neuromodulation had significant effect on BAO without changes in MAO levels. CONCLUSIONS: Low frequency permanent vagal neuromodulation affects gastric function and influences food intake in the experimental model.

Microchip vagal pacing reduces food intake and body mass.

BACKGROUND/AIMS: Morbid obesity is an increasing problem worldwide. In many patients pharmacotherapy is ineffective and these cases are treated by surgery. Different types of gastroplasty and gastric bypasses have been described. However, all of these ablative surgical methods are irreversible and often replace obesity by other disorders. Neuromodulation of vagal activity is a method of inducing significant changes in stomach motility. We developed a pre-programmed microchip able to pace vagal afferent activity by changing current parameters. The aim of our study was to evaluate long-term effects of vagal neuromodulation on food intake and body mass in rabbits. METHODOLOGY: Twenty-seven healthy male adult New Zealand white rabbits were included into the study and divided into three groups: A, B and C, 9 animals each. Microchips were implanted by laparotomy access. Anesthesia was obtained by continuous intravenous infusion of propofol. Microchips were fixed in the preperitoneal pocket and two electrodes were positioned on the posterior vagus in group A by forward, and in group B by backward pacing. Control group C was sham operated by laparotomy and only vagal nerves preparation was performed. The following parameters were estimated: daily solid food and liquids intake, amount of feces, body mass and heart rate. RESULTS: Within four weeks after operation body mass in group B had decreased up to 12% (P = 0.029), whereas in group A and C changed to -3% and +2%, respectively. An 87% solid food intake was observed in group A, 60% in group B (P < 0.01), and 143% in group C, compared to preoperative period. No significant differences were observed between groups A, B and C for liquids intake. Total feces weight changes corresponded to solid food intake. Heart rate decreased intraoperatively to 78% and 74% in groups A and B, respectively. CONCLUSIONS: Microchip mediated functional gastroplasty significantly reduces food intake and body mass. Obtained results encourage using similar treatment in morbid obesity human patients. However, further studies are required.