Esófago porcino: modelo ex vivo de entrenamiento laparoscópico para la miotomía de Heller y funduplicatura de Dor / Porcine esophagus: ex vivo laparoscopic training model for Heller's myotomy and Dor's funduplication

El dominio de procedimientos avanzados en laparoscopia es fundamental para los cirujanos, por ello el entrenamiento es imprescindible. La miotomía de Heller y funduplicatura de Dor requieren el desarrollo de habilidades y destrezas para realizar la cirugía de forma segura y eficaz, superar la curva de aprendizaje es un reto para el cirujano en formación, por lo que se propone el esófago porcino como modelo ex vivo de entrenamiento laparoscópico, con el fin de permitir desarrollar las habilidades necesarias y así llevar a cabo con éxito el procedimiento quirúrgico.Objetivo : Aplicar el esófago porcino como modelo ex vivo para el entrenamiento laparoscópico de la miotomía de Heller y funduplicatura de Dor.Métodos : Se realizó un estudio prospectivo, experimental y longitudinal, aplicado en un período de 17 semanas, en sesiones de 1 hora cada una, una sesión por semana.Resultados : Se llevaron a cabo 17 prácticas realizadas por el autor, evaluadas por cirujanos expertos, observando un aumento de la puntuación obtenida en la escala GOALS y disminución del tiempo de ejecución a medida que aumentaba el número de prácticas con una correlación altamente significativa, según la tau-B de Kendall (p=0,000).Conclusión : El modelo ex vivo permitió recrear la mayoría de los pasos quirúrgicos y demostró ser una herramienta útil y valiosa, disminuyendo el tiempo de ejecución del procedimiento y aumentando significativamente las habilidades laparoscópicas(AU)

Mastery of advanced procedures in laparoscopy is important for surgeons, therefore training is essential. Heller's myotomy and Dor's fundoplication require the development of abilities and skills to perform the surgery safely and effectively, overcoming the learning curve is a challenge for the surgeon in training, so the porcine esophagus is proposed as an ex vivo model of laparoscopic training in order to develop the necessary skills to successfully carry out the surgical procedure. Objective: To apply the porcine esophagus as an ex vivo model for laparoscopic training of Heller's myotomy and Dor's fundoplication. Methods: A prospective, experimental and longitudinal study was carried out, applied by the authors in a period of 17 weeks, in sessions of 1 hour each, one session per week. Results: 17 practices carried out by the author were carried out, evaluated by expert surgeons, observing an increase in the score obtained on the GOALS scale and a decrease in execution time as the number of practices with a high significant influence increase, according to Kendall's tau-B (p=0.000). Conclusion: The ex vivo model allowed recreating most of the surgical steps and stood out as a useful and valuable tool, decreasing the execution time of the procedure and significantly increasing laparoscopic skills(AU)

Therapeutic silencing miR-146b-5p improves cardiac remodeling in a porcine model of myocardial infarction by modulating the wound reparative phenotype

Fibrotic remodeling is an adverse consequence of immune response-driven phenotypic modulation of cardiac cells following myocardial infarction (MI). MicroRNA-146b (miR-146b) is an active regulator of immunomodulation, but its function in the cardiac inflammatory cascade and its clinical implication in fibrotic remodeling following MI remain largely unknown. Herein, miR-146b-5p was found to be upregulated in the infarcted myocardium of mice and the serum of myocardial ischemia patients. Gain- and loss-of-function experiments demonstrated that miR-146b-5p was a hypoxia-induced regulator that governed the pro-fibrotic phenotype transition of cardiac cells. Overexpression of miR-146b-5p activated fibroblast proliferation, migration, and fibroblast-to-myofibroblast transition, impaired endothelial cell function and stress survival, and disturbed macrophage paracrine signaling. Interestingly, the opposite effects were observed when miR-146b-5p expression was inhibited. Luciferase assays and rescue studies demonstrated that the miR-146b-5p target genes mediating the above phenotypic modulations included interleukin 1 receptor associated kinase 1 (IRAK1) and carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1). Local delivery of a miR-146b-5p antagomir significantly reduced fibrosis and cell death, and upregulated capillary and reparative macrophages in the infarcted myocardium to restore cardiac remodeling and function in both mouse and porcine MI models. Local inhibition of miR-146b-5p may represent a novel therapeutic approach to treat cardiac fibrotic remodeling and dysfunction following MI.

Review of the UBC Porcine Model of Traumatic Spinal Cord Injury

Traumatic spinal cord injury (SCI) research has recently focused on the use of rat and mouse models for in vivo SCI experiments. Such small rodent SCI models are invaluable for the field, and much has been discovered about the biologic and physiologic aspects of SCI from these models. It has been difficult, however, to reproduce the efficacy of treatments found to produce neurologic benefits in rodent SCI models when these treatments are tested in human clinical trials. A large animal model may have advantages for translational research where anatomical, physiological, or genetic similarities to humans may be more relevant for pre-clinically evaluating novel therapies. Here, we review the work carried out at the University of British Columbia (UBC) on a large animal model of SCI that utilizes Yucatan miniature pigs. The UBC porcine model of SCI may be a useful intermediary in the pre-clinical testing of novel pharmacological treatments, cell-based therapies, and the “bedside back to bench” translation of human clinical observations, which require preclinical testing in an applicable animal model.

Review of the UBC Porcine Model of Traumatic Spinal Cord Injury

Traumatic spinal cord injury (SCI) research has recently focused on the use of rat and mouse models for in vivo SCI experiments. Such small rodent SCI models are invaluable for the field, and much has been discovered about the biologic and physiologic aspects of SCI from these models. It has been difficult, however, to reproduce the efficacy of treatments found to produce neurologic benefits in rodent SCI models when these treatments are tested in human clinical trials. A large animal model may have advantages for translational research where anatomical, physiological, or genetic similarities to humans may be more relevant for pre-clinically evaluating novel therapies. Here, we review the work carried out at the University of British Columbia (UBC) on a large animal model of SCI that utilizes Yucatan miniature pigs. The UBC porcine model of SCI may be a useful intermediary in the pre-clinical testing of novel pharmacological treatments, cell-based therapies, and the “bedside back to bench” translation of human clinical observations, which require preclinical testing in an applicable animal model.

A porcine model of orthotopic left lung transplantation / 中国实验动物学报

Objective To establish a porcine allogeneic left lung orthotopic transplantation model to closely simu-late human lung transplantation.Methods Twelve Huanjiang mini-pigs were used as donors and 12 Bama mini-pigs as recipients.The left lung orthotopic transplantation was completed by the left fourth intercostal thoracotomy.At 1 h, 2 h, 4 h, 6 h, 12 h after transplantation, the left and right pulmonary artery pressure were measured, the left and right pulmonary vein blood gas was analyzed, and samples of the left and right lung tissues were taken to determine the water content and for pathological examination.Results All animals survived, and the transplanted pulmonary vein blood PaO2/FiO2 and PAP were rised along with the prolonged postoperative time, compared with those of the recipient normal lung showing a signifi-cant difference (P<0.05).With the pass of time, there were increasing edema, inflammatory cell infiltration, RBC ooze, thickening of alveolar wall in the transplanted lung tissue, and some alveolar lumen occlusion and lung tissue consolidation. The water content of the transplanted lung tissue was increased significantly compared with that in the recipient lung tissue ( P<0.05 ) .Conclusions The established method in this study provides an ideal animal model for research on lung transplantation ischemia-reperfusion injury and immune rejection mechanism.

Live trauma surgery demonstration with a porcine model is valuable training for physicians and nurses / 医学教育

Sources of research funding: We gratefully acknowledge the support of the 17th Congress of the Japanese Society for Emergency Medicine support of this program.<br>Ethical considerations: The program was conducted after receiving approval from the Institutional Animal Experiment Committee of the Jichi Medical University, and in accordance with the Institutional Regulation for Animal Experiments and Fundamental Guideline for Proper Conduction of Animal Experiment and Related Activities in Academic Research Institutions under the jurisdiction of the Ministry of Education, Culture, Sports, Science and Technology of Japan. It was approved on April 9th, 2014. The approval number is 14-225.<br>Disclosure of conflicts of interests: We gratefully acknowledge the contributions of personnel from Panasonic Corp. who enabled the interactive communication system.<br>Abstract<br>Introduction: Live surgery demonstrations have been widely used in surgical education. However, they cannot be used to demonstrate trauma surgery due to the emergency situation and lack of informed consent. The aim of this study was to conduct a live demonstration of trauma surgery with a porcine model to increase educational opportunities in trauma surgery.<br>Methods: Live demonstration was conducted at the Center for Development of Advanced Medical Technology (CDAMtec) , Jichi Medical University, Japan. An experienced trauma surgeon instructed three trainees during a live demonstration using pre-planned injuries in a porcine model. A six-point Likert Scale was used on a written survey to determine the value of the program to the viewers. Free-form written comments were also obtained from the participants. Live images of the surgical field were transmitted to a lecture room by a closed wireless LAN with interactive bidirectional audio capability.<br>Results: Eighty-three participants viewed this live demonstration and completed the questionnaire. Participants were highly satisfied with the live demonstration (mean survey scores: 4.6-5.1/6) , and gave very positive feedback concerning the educational value of this program. Nine free-form comments were submitted, which revealed that the participants felt they could acquire concrete skills for trauma surgery.<br>Discussion: Live demonstrations for trauma surgery using a porcine model are a feasible and effective educational tool to demonstrate technical procedures and non-technical skills, with possible added advantages regarding the ethical considerations of performing a live surgery demonstration.

Periapical tissue reaction to calcium phosphate root canal sealer in porcine model.

Background: Calcium phosphate cements (CPC) are a group of biomaterials possessing wide scope of use in various branches of medical science. These materials have been proposed to be highly biocompatible and osteoconductive. This study is based on a newly developed CPC formulation (Chitra-CPC) and is aimed at the evaluation of its biocompatibility through an Endodontic Usage Test in a porcine study model. Objective: To evaluate the periapical tissue reaction to Chitra-CPC when used as a root canal sealer/filler material in comparison with a resin sealer, AH Plus (Dentsply). Materials and Methods: The procedure was done on porcine animal model following the ISO 7405 criteria. The material was implanted intentionally into the periapical area of 36 teeth through a root canal procedure carried out in six animals which were divided equally among 1-month and 3-month time periods. Results were based on the histological evaluation of the autopsied specimens after the prescribed time periods. Results: Mild to moderate periapical tissue reaction was found in Chitra-CPC samples belonging to the 1-month time period, whereas majority of the 3-month CPC samples showed an absence of inflammation. Samples of AH Plus in 1-month period showed severe to moderate inflammation, whereas 3-month AH Plus samples had a mild to moderate inflammation. Conclusions: Chitra-CPC is a biocompatible material.

Effect of mechanical ventilation guided by esophageal pressure on hemodynamics and oxygen metabolism of SAP porcine model with IAH / 中华急诊医学杂志

Objective To study the effect of mechanical ventilation guided by esophageal pressure on hemodynamics and oxygen metabolism of severe acute pancreatitis (SAP) swine model with intra-abdominal hypertension (IAH) Methods By self-controlled study,SAP model was made by infusing sodium taurocholate (5％) into the pancreatic duct in 6 domestic swine.Mechanical ventilator mode was volumeassist control with tidal volume 10 ml/kg ; FiO2 40％ and PEEP 5 cm H2O (routine ventilation) given to SAP model swine.After 3 h ventilation,pneumo-peritoneum was made with N2 gas to increase the intraabdominal pressure (IAP) to 25 mm Hg in SAP swine.Three more hours later,PEEP was adjusted as the measurement of esophageal pressure (Pes guided ventilation) to such a level that trans-pulmonary pressure stayed above 0 cm H2O during end-expiratory occlusion.During the investigation period,heart rate (HR),cardiac output index (CI),central venous pressure (CVP),mean arterial pressure (MAP) and pulmonary arterial wedge pressure (PAWP) were continuously recorded with the aid of Swan-Ganz catheter and ECG monitor,and oxygen partial pressure of artery (PaO2) and carbon dioxide partial pressure of artery (PaCO2) were measured by blood-gas analysis.In addition,systemic oxygen delivery (DO2) and systemic oxygen consumption (VO2) were calculated by using the data of blood-gas analysis of arterial and central venous blood.Results No swine model was subjected to barotrauma.After routine mechanical ventilation,there were significant differences in HR,CI,MAP,CVP,PAWP,Ppeak,Pplat,Pes,pulmonary compliance (Cstat),PaO2,and DO2 between SAP and IAH in swine (all P ＜ 0.05).Compared with routine ventilation,however,PaO2 and Cstat improved significantly with lower CI and increased Pplat after PEEP adjusted according to measurements of esophageal pressure (all P ＜ 0.05).The lactate decreased significantly after esophageal pressure guided ventilation (all P ＜ 0.05).There were no significant changes in PaCO2,HR,MAP,CVP and PAWP in IAH swine after mechanical ventilation with routine parameters (all P ＞ 0.05).Conclusions There were remarkable effects on oxygen metabolism in response to mechanical ventilation guided by esophageal pressure.In case of clinical application of mechanical ventilation,the results of this study are in favor of setting transpulmonary pressure according to measurements of esophageal pressure in SAP patients with IAH in an early stage.

The immune function influence of the CD4 + T helper cell after the treatment of continuous blood purification in a porcine model with multiple organ dysfunction syndrome / 中国小儿急救医学

Objective To investigate the levels of Th1 and Th2 cell in the peripheral and the cytokines (IFN-γ,TNF-α,IL-12,IL-10,IL-4) in the culture medium at different time in the porcine model with multiple organ dysfunction syndrome(MODS) after continuous blood purification(CBP). Methods Twenty-four young porcines were given intravenous infusion of endotoxin to induce MODS, then were randomly divided into 2 groups:CBP group(n = 12) and MODS group without CBP(n = 12). Continuous venovenous hemodiafiltration (CVVHDF) was the main mode for CBP. At baseline, onset of MODS, and 2 h,4 h,6 h after treatment of CVVHDF,we picked the blood respectively to separate the T helper cell using the beads,detected the Th1 and Th2 cell by FACS and detected the cytokines (IFN-γ,TNF-α,IL-12,IL-10,IL-4) in the culture medium by ELISA. Results The MODS group showed a obvious rise in TNF-α,the drop tendency in IL-12,IFN-γ,IL-10,Th1/Th2 ratio, and no significant change in IL-4. After the treatment, the CBP group showed the drop in TNF-α and IL-4;and increase in IL-12,IFN-γ,IL-10 and Th1/Th2 ratio. Conclusion CBP helps to dear immune function,and restore the balance of Th1/Th2 in porcine MODS model.

The feasibility of an animal laboratory for teaching surgical techniques to medical students: Teaching in a non-clinical environment / 医学教育

There is a need for suitable non-clinical teaching models in undergraduate medical education.This study was undertaken to demonstrate the feasibility of using an animal model to teach surgical skills to medical students.Two gastrotomies were created in each pig, and then closed using stapled and hand-sewn techniques.Animals were sacrificed seven days later and the closures examined grossly and histologically.<BR>1) Medical students, as surgeons with minimal experience, are able to significantly reduce the time needed to perform closure of a gastrotomy in a porcine model using surgical staplers compared to a hand-sewn closure.<BR>2) Medical students can perform advanced abdominal surgery techniques with adequate instruction resulting in excellent surgical outcomes in a porcine model.<BR>3) The porcine model is a valuable tool to teach animal ethics as well as basic surgical techniques in the non-clinical environment and may help to increase interest among students in a surgical career.

Influence of stent expansion states on platelet deposition in an extracorporeal porcine arteriovenous shunt model using a multichannel perfusion chamber

Limited data are available about incomplete stent expansion (SE) on platelet deposition (PD). We examined PD following different SE using an extracorporeal porcine arteriovenous shunt model to which a perfusion chamber with four parallel silastic tubes were connected. Blood flow was set at a 20 and 100 mL/min in 1.8 and 3.1 mm diameter tubes, respectively. P154 stents were deployed completely (Group A, n=15) or incompletely (Group B, n=15) in 1.8 mm (n=13) and 3.1 mm (n=17) tubes. 51Cr-labelled platelet autologous blood was injected 1 hr before the perfusion. After 15 min-perfusion, the testing tubes were assessed for radioactivity counts. In-stent cross sectional area was measured by intravascular ultrasound. There was a significant difference in PD between group A and B regardless of channel size (118+/-18.4 vs 261.4+/-52.1 pits x 10(6)/cm2, p<0.05). With adjusted shear rate and similar stenosis, PD was similar in both tubes. In smaller 1.8 mm tubes, a stenosis as subtle as 10% was associated with a significant PD difference (226.1+/-20 vs 112.9+/-20.5 plts x 10(6)/cm2, p<0.005). This model enabled a repetitive, simultaneous comparison of PD following different SE states. It seems that the quality of SE remains crucial in smaller channels.

Comparison of Core(R) stent and Palmaz-Schatz(R) stent in a Porcine Stent Restenosis Model

BACKGROUND AND OBJECTIVES: The purpose of this study is to compare new Core(R) stent and Palmaz-Schatz(R) (PS)stent in a porcine coronary stent restenosis model. METHODS: Twelve pigs underwent balloon injury and followed by implantation of oversized, tubular types of Core(R) and PS(R) stents (stent/artery ratio 1.2:1) in twenty-four coronary arteries. Quantitative analyses of initial and follow-up coronary angiograms at 4 weeks after stenting were performed. By morphometric analysis, the extents of injury and neointimal area were compared between two stented groups. The stent flexibility and longitudinal staightening effect were compared between two groups by the bending test and measurement of the angle changes. RESULTS: 1) Reference vessel diameter, stented artery diameter, and diameter stenosis were not different between two groups. 2) The neointimal area was significantly smaller in the Core(R) stent group than in the PS(R) stent group (1.81+/-0.67 mm2 vs 2.93+/-0.94 mm2, p=0.006). 3) Core(R) stent had more flexible property than PS(R) stent. 4) The angle changes after stent implantation were not different between two groups(13.2+/-9.0, 14.4+/-11.1, p=0.88). CONCLUSION: Core(R) stent is effective in the inhibition of neointimal formation in a porcine coronary stent restenosis model. And this results may be due to more improved flexibility of the Core(R) stent and further clinical trials may be needed.