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Abstract Background The porcine gall bladder and cystic duct gained attention in experimental research aimed at improving human clinical care. While the common bile duct has been investigated before, there is almost no data on the porcine cystic duct. Its relevance for research originates from its potential use in xenotransplantation. Methods We included 10 consecutive pigs (1♀, 9♂) that had been sacrificed after participation in another study. At necropsy, the distance from the biliary papilla to the gall bladder (gall bladder distance) was measured. The cystic duct was then subjected to linear traction. Ethical approval for the study was granted. Associations between force measurements and anatomical parameters were tested by correlation analysis. Results The pigs had a mean body weight of 21.9 kg (standard deviation 2 kg), a mean liver weight of 590 g (standard deviation 88 g), and a mean crown rump length of 67.3 cm (standard deviation 3 cm). The gall bladder distance was 8.2 cm (95% confidence interval: 7.6–8.7 cm). The cystic duct withstood mean linear traction forces of 4.8 N (95% confidence interval: 3.7–5.8 N) and could be elongated by a mean of 6 mm (95% confidence interval: 3.9–8 mm). Linear breaking strength was neither correlated to gall bladder distance (R = 0.3, 95% confidence interval: − 0.41 to 0.78, P = 0.406) or crown rump length (R = 0.42, 95% confidence interval: − 0.28 to 0.83, P = 0.222) nor liver weight (R = 0.02, 95% confidence interval: − 0.62 to 0.64, P = 0.954) or body weight (R = 0.36, 95% confidence interval: − 0.35 to 0.81, P = 0.304). This was also true for gall bladder distance. Conclusions Our study indicates that allometric parameters were not associated with the gall bladder distance or its resistance to traction forces. Consequently, substantial variation of these parameters can be expected in these surgically important parameters, which cannot be derived from easily accessible anatomical parameters.

Background: The porcine gall bladder and cystic duct gained attention in experimental research aimed at improving human clinical care. While the common bile duct has been investigated before, there is almost no data on the porcine cystic duct. Its relevance for research originates from its potential use in xenotransplantation. Methods: We included 10 consecutive pigs (1♀, 9♂) that had been sacrificed after participation in another study. At necropsy, the distance from the biliary papilla to the gall bladder (gall bladder distance) was measured. The cystic duct was then subjected to linear traction. Ethical approval for the study was granted. Associations between force measurements and anatomical parameters were tested by correlation analysis. Results: The pigs had a mean body weight of 21.9 kg (standard deviation 2 kg), a mean liver weight of 590 g (standard deviation 88 g), and a mean crown rump length of 67.3 cm (standard deviation 3 cm). The gall bladder distance was 8.2 cm (95% confidence interval: 7.6–8.7 cm). The cystic duct withstood mean linear traction forces of 4.8 N (95% confidence interval: 3.7–5.8 N) and could be elongated by a mean of 6 mm (95% confidence interval: 3.9–8 mm). Linear breaking strength was neither correlated to gall bladder distance (R = 0.3, 95% confidence interval: − 0.41 to 0.78, P = 0.406) or crown rump length (R = 0.42, 95% confidence interval: − 0.28 to 0.83, P = 0.222) nor liver weight (R = 0.02, 95% confidence interval: − 0.62 to 0.64, P = 0.954) or body weight (R = 0.36, 95% confidence interval: − 0.35 to 0.81, P = 0.304). This was also true for gall bladder distance. Conclusions: Our study indicates that allometric parameters were not associated with the gall bladder distance or its resistance to traction forces. Consequently, substantial variation of these parameters can be expected in these surgically important parameters, which cannot be derived from easily accessible anatomical parameters. [ABSTRACT FROM AUTHOR]

Heart valves serve a vital hemodynamic function to ensure unidirectional blood flow. Additionally, native heart valves serve biological functions such as growth and self‐repair. Heart valve implants mimic the hemodynamic function of native heart valves, but are unable to fulfill their biological functions. We developed partial heart transplantation to deliver heart valve implants that fulfill all functions of native heart valves. This is particularly advantageous for children, who require growing heart valve implants. This invited review outlines the past, present and future of partial heart transplantation. [ABSTRACT FROM AUTHOR]

The 38th Annual Meeting of the Academy of Surgical Research took place in La Jolla, CA, USA, on 14–16 September 2022. For more than 40 years, the Academy has promoted the advancement of professional and academic standards in education and research in the arts and sciences of experimental surgery. The diverse membership includes technicians, veterinarians, medical doctors, and biomedical researchers from industry, academia, and complementary disciplines supporting discovery and translational research. At the annual meeting, this experimental surgery community shared the latest in research and surgical techniques, along with professional development that included cutting-edge lectures, hands-on training, and qualification exams for certifications. Over 130 participants from 26 different states and 3 countries were in attendance for the scientific program and social events. Two scientific tracks featuring three keynotes were presented together with a poster session. Participants could practice hands-on surgical techniques in dry and wet labs that ranged from applied surgical anesthesia to minimally invasive surgical skills, followed by in-depth discussion roundtables focused on improving study design and best practices in anesthesia and analgesia. The social program provided participants the opportunity to connect in person with potential mentors and collaborators. We present the highlights from this meeting in this report, together with selected abstracts that illustrate the diverse scientific expertise of the Academy and promising new surgical research.

Vagus nerve stimulation (VNS) is an adjuvant neuromodulation therapy for the treatment of refractory epilepsy. However, the mechanisms behind its effectiveness are not fully understood. Our aim was to develop a VNS protocol for the Genetic Audiogenic Seizure Hamster from Salamanca (GASH/Sal) in order to evaluate the mechanisms of action of the therapy. The rodents were subject to VNS for 14 days using clinical stimulation parameters by implanting a clinically available neurostimulation device or our own prototype for laboratory animals. The neuroethological assessment of seizures and general behavior were performed before surgery, and after 7, 10, and 14 days of VNS. Moreover, potential side effects were examined. Finally, the expression of 23 inflammatory markers in plasma and the left-brain hemisphere was evaluated. VNS significantly reduced seizure severity in GASH/Sal without side effects. No differences were observed between the neurostimulation devices. GASH/Sal treated with VNS showed statistically significant reduced levels of interleukin IL-1β, monocyte chemoattractant protein MCP-1, matrix metalloproteinases (MMP-2, MMP-3), and tumor necrosis factor TNF-α in the brain. The described experimental design allows for the study of VNS effects and mechanisms of action using an implantable device. This was achieved in a model of convulsive seizures in which VNS is effective and shows an anti-inflammatory effect. [ABSTRACT FROM AUTHOR]

This article examines the Gothic trope of White racial transformation in Robert Montgomery Bird's Sheppard Lee (1836) and Jordan Peele's Get Out (2017). These seemingly disparate texts both feature White men who turn Black via supernatural body hopping or experimental surgery. In these texts, Blackness acts as an emotional and material resource for White characters that perversely bolsters Whiteness by escaping it. Little-known outside of antebellum specialisms, Sheppard Lee enhances our understanding of race in the Gothic by considering why Whiteness may be rejected in the early nation. Written in the context of blackface minstrelsy, the novel transforms downwardly mobile Sheppard into an enslaved man as a respite from the pressures of economic success. Get Out builds on its nineteenth-century precursors by showing the Black body as a desired and necessary vessel for the "post-racial" White American self, who swaps their physical Whiteness for Blackness to extend or enhance their own life, turning Black men into extensions and enforcers of White middle-class culture. In uniting these texts through the lens of critical Whiteness studies, this article argues that White racial transformation is a long-held tradition in the US Gothic that not only expresses White desires and anxieties, but itself transforms in each specific historical racial context. [ABSTRACT FROM AUTHOR]

Background: The purpose of this report is to describe the seminal case of a near-term human fetus with a life-threatening left diaphragmatic hernia that underwent fetoscopic tracheal occlusion (FETO) combined with fetoscopic partial removal of herniated bowel from the fetal chest by fetoscopic laparoschisis (FETO-LAP). Case summary: A life-threatening left diaphragmatic hernia (liver-up; o/e LHR of ≤25%; MRI lung volume ≤ 20%) was observed in a human fetus at 34 weeks of gestation. After counselling the mother about the high risks of postnatal demise if left untreated, the expected limitations of fetoscopic tracheal occlusion (FETO), and the previously untested option of combining FETO with fetoscopic laparoschisis, i.e., partial removal of the herniated bowel from the fetal chest (FETO-LAP), she consented to the latter novel treatment approach. FETO-LAP was performed at 36 + 5 weeks of gestation under general maternofetal anesthesia. Mother and fetus tolerated the procedure well. The neonate was delivered and the balloon removed on placental support at 37 + 2 weeks of gestation. On ECMO, a rapid increase in tidal volume was seen over the next eight days. Unfortunately, after this period, blood clots obstructed the ECMO circuit and the neonate passed away. Discussion: This seminal case shows that in a fetus with severe left diaphragmatic hernia, partial removal of the herniated organs from the fetal chest is not only possible by minimally invasive fetoscopic techniques but also well tolerated. As the effect of FETO alone is limited in saving severely affected fetuses, combining FETO with fetoscopic laparoschisis (FETO-LAP) offers a new therapeutic route with multiple, potentially life-saving implications. [ABSTRACT FROM AUTHOR]

Need: Electrical stimulation (ES) is a promising therapy for multisegmental gastrointestinal (GI) motility disorders such as gastroparesis with slow-transit constipation or chronic intestinal pseudo-obstruction. Wireless communicating GI devices for smart sensing and ES-based motility modulation will soon be available. Before placement, a potential benefit for each GI segment must be intraoperatively assessed. Technical Solution: A minimally invasive multisegmental electromyography (EMG) analysis with ES of the GI tract is required. Proof of Concept: Two porcine experiments were performed with a laparoscopic setup. Multiple hook-needle electrodes were subserosally applied in the stomach, duodenum, jejunum, ileum, and colon. EMG signals were acquired for computer-assisted motility analysis. Gastric ES, duodenal ES, jejunal ES, ileal ES, and colonic ES were applied. Next Steps: Further technological and rapid regulatory solutions are desired to initialize a clinical trial of the next generation devices in the near future. Conclusion: We demonstrate a laparoscopic strategy with EMG analysis and ES of multiple GI segments. Thus, GI function may be evaluated before theranostic devices are placed. Extended GI resection or organ transplantation may be delayed or even avoided in affected patients. [ABSTRACT FROM AUTHOR]

Traumatic spinal cord injury (SCI) is a devastating condition without an effective therapy. Cellular therapies are among the promising treatment strategies. Adult stem cells, such as mesenchymal stem cells, are often used clinical research for their immunomodulatory and regenerative potential. This study aimed to evaluate the effect of human adipose tissue-derived stem cells (ADSC) infusion through the cauda equina in rats with SCI. The human ADSC from bariatric surgery was isolated, expanded, and characterized. Wistar rats were subjected to blunt SCI and were divided into four groups. Two experimental groups (EG): EG1 received one ADSC infusion after SCI, and EG2 received two infusions, the first one after SCI and the second infusion seven days after the injury. Control groups (CG1 and CG2) received infusion with a culture medium. In vivo, cell tracking was performed 48 h and seven days after ADSC infusion. The animals were followed up for 40 days after SCI, and immunohistochemical quantification of myelin, neurons, and astrocytes was performed. Cellular tracking showed cell migration towards the injury site. ADSC infusion significantly reduced neuronal loss, although it did not prevent the myelin loss or enhance the area occupied by astrocytes compared to the control group. The results were similar when comparing one or two cell infusions. The injection of ADSC distal to the injured area was shown to be a safe and effective method for cellular administration in spinal cord injury. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Right ventricle to pulmonary artery anatomic discontinuity is common in complex congenital heart malformations. Handsewn conduits are a practised method of repair. In a proof-of-concept study, we evaluated pulmonary valve replacement with a handsewn pericardial valved pulmonary conduit in vitro and in vivo. METHODS: A pulsatile flow-loop model (in vitro) and an acute 60-kg porcine model (in vivo) were used. With echocardiography and pressure catheters, baseline geometry and fluid dynamics were measured. The pulmonary valve was replaced with a handsewn glutaraldehyde-treated pericardial valved pulmonary conduit corresponding to a 21-mm prosthetic valve, after which geometric measurements and fluid dynamics were reassessed. RESULTS: In vitro, 15 pulmonary trunks at 4 l/min and 13 trunks at 7 l/min, and in vivo, 11 animals were investigated. The valved pulmonary conduit was straightforward to produce at the operating table and easy to suture in place. All valves were clinically sufficient in vitro and in vivo. The mean transvalvular pressure gradient in the native valve and the conduit was 8 mmHg [standard deviation (SD): 2] and 7 mmHg (SD: 2) at 4 l/min in vitro, 19 mmHg (SD: 3) and 17 mmHg (SD: 4) at 7 l/min in vitro and 3 mmHg (SD: 2) and 6 mmHg (SD: 3) in vivo. CONCLUSIONS: Our proof-of-concept demonstrates no early evidence of structural damage to the conduit, and the fluid dynamic data were acceptable. The handsewn conduit can be produced at the operating table. Conduits to restore the right ventricle to pulmonary artery (RV–PA) anatomic discontinuity are used routinely in complex congenital malformations that involve the right ventricular outflow tract. [ABSTRACT FROM AUTHOR]

This article describes in detail the essential stereotaxic neurosurgery to develop the electric experimental kindling model in mice. To date, available literature describing the methodology of the kindling model is very poor and usually neglects many relevant details about the neurosurgery, such as the manufacture of the electrodes, accurate stereotaxic coordinates of the amygdala nuclei, and the general surgery procedures (e.g., anesthesia, postsurgical recovery, fit survival of the animal’s). The electric kindling model produces a progressive development of generalized tonic-clonic seizures, which can be assessed by electroencephalography and behavioral responses. The seizures displayed are produced by a repeated low-intensity electrical stimulation in specific regions of the brain that is achieved through the previous implantation of electrodes. In this study, the aim was to implant the electrodes in basolateral amygdaloid nucleus (BLA). In order to successfully establish the kindling experimental model, neurosurgery to place the electrodes is an essential step to develop the epileptogenic phenomenon. It crucial that the surgery is carried out with exceptional exactitude, because in that way the experimental model represents an accurate and valid tool to study and understand epilepsy and the results obtained can be used to develop further strategies in epilepsy clinical research.

Modern therapy concepts are of limited success in patients with cholestasis (e.g., biliary occluding malignancies). Therefore, we established a new animal model enabling simultaneous investigation of liver regeneration and hepato-biliary remodelling in biliary obstructed and biliary non-obstructed liver lobes.

Background Ischemic preconditioning (IPC), either direct (DIPC) or remote (RIPC), is a procedure aimed at reducing the harmful effects of ischemia-reperfusion (I/R) injury. Objectives To assess the local and systemic effects of DIPC, RIPC, and both combined, in the pig liver transplant model. Materials and methods Twenty-four pigs underwent orthotopic liver transplantation and were divided into 4 groups: control, direct donor preconditioning, indirect preconditioning at the recipient, and direct donor with indirect recipient preconditioning. The recorded parameters were: donor and recipient weight, graft-to-recipient weight ratio (GRWR), surgery time, warm and cold ischemia time, and intraoperative hemodynamic values. Blood samples were collected before native liver removal (BL) and at 0 h, 1 h, 3 h, 6 h, 12 h, 18 h, and 24 h post-reperfusion for the biochemical tests: aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), creatinine, BUN (blood urea nitrogen), lactate, total and direct bilirubin. Histopathological examination of liver, gut, kidney, and lung fragments were performed, as well as molecular analyses for expression of the apoptosis-related BAX (pro-apoptotic) and Bcl-XL (anti-apoptotic) genes, eNOS (endothelial nitric oxide synthase) gene, and IL-6 gene related to inflammatory ischemia-reperfusion injury, using real-time polymerase chain reaction (RT-PCR). Results There were no differences between the groups regarding biochemical and histopathological parameters. We found a reduced ratio between the expression of the BAX gene and Bcl-XL in the livers of animals with IPC versus the control group. Conclusions DIPC, RIPC or a combination of both, produce beneficial effects at the molecular level without biochemical or histological changes.

Purpose To compare the adaptation processes of the remaining jejunum or ileum after extensive intestinal resection in a growing animal model. Materials and Methods Forty 21-day old rats were divided into four groups: JG: remaining jejunum group – ileal enterectomy; IG: ileum remaining group – jejunum enterectomy; SHAM: sham-operated group – open-and-close laparotomy; and NO: non-operated animals. Results After 3 weeks, JG and IG animals had decreased weights comparing to SHAM and NO animals (p = 0.017 and p = 0.005, respectively). The histomorphometric analysis showed that in JG animals the villi were higher than in SHAM, NO, and IG animals (p = 0.007, p = 0.008, and p = 0.01), the depth of crypts in JG and IG animals was greater than in NO and SHAM animals (p = 0.03, p = 0.002, and p = 0.003 respectively), and muscle layer thickness of the jejunum of JG animals had values greater than SHAM and NO animals (p = 0.01 and p = 0.02, respectively). The Ki-67 expression in the ileum was higher in comparison with the jejunum (p = 0.014). The pro-apoptotic gene (Bax) expression was decreased in JG animals compared to IG, SHAM, and NO animals (p = 0.013, p = 0.024, and p = 0.021). The anti-apoptotic gene (Bcl-XL) expression was decreased in JG animals in comparison to IG and NO animals (p = 0.002 and p = 0.046) although it was increased in the colon of IG animals in comparison to JG, SHAM, and NO animals (p = 0.002, p = 0.001, and p = 0.001, respectively). The Bax/Bcl-XL ratio was higher in JG than in IG animals (p = 0.011). Conclusion Adaptive responses seemed to be more effective in the ileum than in the jejunum.

Introduction several pancreatectomy techniques in rats have been described and utilized for research concerning the pancreas endocrine and exocrine functions. However, we did not find a description of any kind of laparoscopic pancreatectomy in rats in the consulted databases. The objective of this study is to describe a laparoscopic splenic lobe pancreatectomy in rats. Methods ten Wistars rats weighting more then 300 g were operated for standardizing the laparoscopic pancreatosplenectomy technique, aided by previous descriptions of laparoscopic splenectomy and open pancreatectomy in rats. Adjustments have been progressively adopted for technical refinement. Results In five animals a low-cost rat laparoscopic set was used. In other five animals we used a standard laparoscopic set. Three rats died early due to different causes: transection of the gastroesophageal junction, hemorrhagic shock and inadvertent colonic injury. The postoperative period of the other seven rats was uneventful until the seventh postoperative day. Discussion laparoscopic distal pancreatectomy and splenectomy in rats is feasible and safe, even with a low-cost set, in which the results were alike the standard laparoscopic set.

Introduction: on a formal trip to Scotland at the end of 2018 at the traditional and renowned University of Glasgow and your very famous School of Medicine, before the covid-19 pandemic, I was able to spend a day on an official visit to the Glasgow College and Museum of Surgeons, "Lister's House" and many illustrious others, where I was able to study, feel and observe the magnitude of the greatness of the men who preceded with glory, merits, pioneering spirit and a lot of hard work the great discussions for the time and relevant discoveries that would lead to incalculable advances for the development of health science and clinical medicine today, the world is also made up of microbes, every advance in current science depends on the history of our ancestors. Currently we can say that our autoimmune defense system is an appropriate recognition system, more than just a defense system of the body, given the large increase in automine diseases and viral infections with the appearance of the covid-2019 pandemic and its termination. Both Macewen and Lister were great pioneers in their fields. [ABSTRACT FROM AUTHOR]

Background The impact of COVID-19 in healthcare systems globally was unprecedented leading to cancelations of most planned surgical activities. Surgical trainees were redeployed to Intensive Care and Emergency units supporting urgent and unplanned care on COVID-19 patients. Theater exposure, crucial part of surgical training, was reduced to minimal since elective cases were postponed, and emergency operating was carried out by consultants only. Surgical research has also been severely hit with most of the clinical trials been postponed. Teaching activities as well as national and international congresses and surgical courses important tools for continuous professional development were canceled. Methods The primary aim of our study was to summarize the changes in surgical training during the pandemic. This was followed by a review of the existing social media platforms, video-conferencing platforms along with the role of the social media in surgical training. The crucial role of simulation in surgical training was explored and alternative ways of training with engagement of the feedback mechanisms were proposed. The secondary aim was to highlight possible novel educational strategies for the forthcoming post-COVID-19 era. Conclusions The “new” era forced the educational boards to reexamine training curriculums. Innovation strategies and cooperation on the part of surgical residency programs is crucial. Strong leadership is needed, on the part of the education bodies with restructuring of the surgical programmes to accommodate alternative ways of training is necessary to maintain rigorous standards of education and training.

Introduction. The various surgical specialties in our center have used the simulation and experimental surgery resources available for their training tasks in minimally invasive surgery (MIS) in an individualized manner. With this learning model, a great dispersion of effort and expense was observed, so it was decided to create a unified program based on the following: shared learning, synergy among specialties, moderation of the economic cost, and rational use of the facilities. Objective. To describe and assess our consensually designed training program in order to consolidate a shared learning strategy that will enable our residents to acquire and perfect surgical skills in MIS. Materials and methods. The program consists of various increasingly complex phases implemented on a continuous basis throughout the period of specialized training in the virtual laboratory and experimental operating room. The assessment methods were based on quantifiable criteria: percentage of efficiency and completion time of the "McGill Inanimate System for Training and Evaluation of Laparoscopic Skills" (MISTELS) exercises at the beginning and end of the program. An economic study was also conducted. Results. 20 residents have completed the program. Mean times show a significant reduction in each of the exercises. The efficiency percentages at the end of the program were higher than at the beginning (p < 0.001). The cost of the program represented a saving of 67.89%. Conclusion. The new MIS training program improved the quality of learning in a safe environment, establishing common criteria among the different specialties and an improved use of resources. [ABSTRACT FROM AUTHOR]

Background and Objectives: Friable or infected tissue remains a challenge in surgical aortic valve replacement. We recently described the "Caput medusae" method, in which circumferential tourniquets temporarily secure the prosthesis and are then gently knotted. Tourniquets have been shown to develop significantly less force than knots. The current study investigates the critical threshold forces for tissue damage to the aortic annulus. Materials and Methods: In 14 fresh porcine hearts, the aortic valve leaflets were removed and several pledgeted sutures were placed along the annulus at defined locations. The hearts were mounted in a self-constructed device. Incremental traction force was applied to every suture and continuously recorded. The movement of each Teflon pledget was filmed with a high-speed camera. Forces at the moment of pledget "cut-in" as well as complete "tear-out" were determined from the recordings. Results: The average threshold force was determined 9.31 ± 6.04 N for cut-in and 20.41 ± 10.02 N for tear-out. Detailed analysis showed that the right coronary region had lower threshold forces than the other regions (4.77 ± 3.28 N (range, 1.67–12.75 N) vs. 10.67 ± 6.04 N (1.62–26.00 N) for cut-in and 10.67 ± 4.04 N (5.40–18.64 N) vs. 23.33 ± 9.42 N (9.22–51.23 N) for tear-out). The findings are discussed in conjunction with the knot and tourniquet forces from our previous study. Conclusions: Even in healthy tissue, moderate forces can reach a critical level at which a Teflon pledget will cut into the annulus, while a complete tear-out is unlikely. The right coronary portion is more susceptible to damage than the remaining regions. When compared to previous data, forces during manual knotting may exceed the critical cut-in level, while rubber tourniquets may provide a higher safety margin against tissue rupture. [ABSTRACT FROM AUTHOR]

Traumatic spinal cord injury (SCI) is a devastating condition without an effective therapy. Cellular therapies are among the promising treatment strategies. Adult stem cells, such as mesenchymal stem cells, are often used clinical research for their immunomodulatory and regenerative potential. This study aimed to evaluate the effect of human adipose tissue-derived stem cells (ADSC) infusion through the cauda equina in rats with SCI. The human ADSC from bariatric surgery was isolated, expanded, and characterized. Wistar rats were subjected to blunt SCI and were divided into four groups. Two experimental groups (EG): EG1 received one ADSC infusion after SCI, and EG2 received two infusions, the first one after SCI and the second infusion seven days after the injury. Control groups (CG1 and CG2) received infusion with a culture medium. In vivo, cell tracking was performed 48 h and seven days after ADSC infusion. The animals were followed up for 40 days after SCI, and immunohistochemical quantification of myelin, neurons, and astrocytes was performed. Cellular tracking showed cell migration towards the injury site. ADSC infusion significantly reduced neuronal loss, although it did not prevent the myelin loss or enhance the area occupied by astrocytes compared to the control group. The results were similar when comparing one or two cell infusions. The injection of ADSC distal to the injured area was shown to be a safe and effective method for cellular administration in spinal cord injury.

This article describes in detail the essential stereotaxic neurosurgery to develop the electric experimental kindling model in mice. To date, available literature describing the methodology of the kindling model is very poor and usually neglects many relevant details about the neurosurgery, such as the manufacture of the electrodes, accurate stereotaxic coordinates of the amygdala nuclei, and the general surgery procedures (e.g., anesthesia, postsurgical recovery, fit survival of the animal's). The electric kindling model produces a progressive development of generalized tonic-clonic seizures, which can be assessed by electroencephalography and behavioral responses. The seizures displayed are produced by a repeated low-intensity electrical stimulation in specific regions of the brain that is achieved through the previous implantation of electrodes. In this study, the aim was to implant the electrodes in basolateral amygdaloid nucleus (BLA). In order to successfully establish the kindling experimental model, neurosurgery to place the electrodes is an essential step to develop the epileptogenic phenomenon. It crucial that the surgery is carried out with exceptional exactitude, because in that way the experimental model represents an accurate and valid tool to study and understand epilepsy and the results obtained can be used to develop further strategies in epilepsy clinical research. [ABSTRACT FROM AUTHOR]

To compare the adaptation processes of the remaining jejunum or ileum after extensive intestinal resection in a growing animal model. Forty 21-day old rats were divided into four groups: JG: remaining jejunum group – ileal enterectomy; IG: ileum remaining group – jejunum enterectomy; SHAM: sham-operated group – open-and-close laparotomy; and NO: non-operated animals. After 3 weeks, JG and IG animals had decreased weights comparing to SHAM and NO animals (p = 0.017 and p = 0.005, respectively). The histomorphometric analysis showed that in JG animals the villi were higher than in SHAM, NO, and IG animals (p = 0.007, p = 0.008, and p = 0.01), the depth of crypts in JG and IG animals was greater than in NO and SHAM animals (p = 0.03, p = 0.002, and p = 0.003 respectively), and muscle layer thickness of the jejunum of JG animals had values greater than SHAM and NO animals (p = 0.01 and p = 0.02, respectively). The Ki-67 expression in the ileum was higher in comparison with the jejunum (p = 0.014). The pro-apoptotic gene (Bax) expression was decreased in JG animals compared to IG, SHAM, and NO animals (p = 0.013, p = 0.024, and p = 0.021). The anti-apoptotic gene (Bcl-XL) expression was decreased in JG animals in comparison to IG and NO animals (p = 0.002 and p = 0.046) although it was increased in the colon of IG animals in comparison to JG, SHAM, and NO animals (p = 0.002, p = 0.001, and p = 0.001, respectively). The Bax/Bcl-XL ratio was higher in JG than in IG animals (p = 0.011). Adaptive responses seemed to be more effective in the ileum than in the jejunum. [ABSTRACT FROM AUTHOR]

several pancreatectomy techniques in rats have been described and utilized for research concerning the pancreas endocrine and exocrine functions. However, we did not find a description of any kind of laparoscopic pancreatectomy in rats in the consulted databases. The objective of this study is to describe a laparoscopic splenic lobe pancreatectomy in rats. ten Wistars rats weighting more then 300 g were operated for standardizing the laparoscopic pancreatosplenectomy technique, aided by previous descriptions of laparoscopic splenectomy and open pancreatectomy in rats. Adjustments have been progressively adopted for technical refinement. In five animals a low-cost rat laparoscopic set was used. In other five animals we used a standard laparoscopic set. Three rats died early due to different causes: transection of the gastroesophageal junction, hemorrhagic shock and inadvertent colonic injury. The postoperative period of the other seven rats was uneventful until the seventh postoperative day. laparoscopic distal pancreatectomy and splenectomy in rats is feasible and safe, even with a low-cost set, in which the results were alike the standard laparoscopic set. [ABSTRACT FROM AUTHOR]

Ischemic preconditioning (IPC), either direct (DIPC) or remote (RIPC), is a procedure aimed at reducing the harmful effects of ischemia-reperfusion (I/R) injury. To assess the local and systemic effects of DIPC, RIPC, and both combined, in the pig liver transplant model. Twenty-four pigs underwent orthotopic liver transplantation and were divided into 4 groups: control, direct donor preconditioning, indirect preconditioning at the recipient, and direct donor with indirect recipient preconditioning. The recorded parameters were: donor and recipient weight, graft-to-recipient weight ratio (GRWR), surgery time, warm and cold ischemia time, and intraoperative hemodynamic values. Blood samples were collected before native liver removal (BL) and at 0 h, 1 h, 3 h, 6 h, 12 h, 18 h, and 24 h post-reperfusion for the biochemical tests: aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), creatinine, BUN (blood urea nitrogen), lactate, total and direct bilirubin. Histopathological examination of liver, gut, kidney, and lung fragments were performed, as well as molecular analyses for expression of the apoptosis-related BAX (pro-apoptotic) and Bcl-XL (anti-apoptotic) genes, eNOS (endothelial nitric oxide synthase) gene, and IL-6 gene related to inflammatory ischemia-reperfusion injury, using real-time polymerase chain reaction (RT-PCR). There were no differences between the groups regarding biochemical and histopathological parameters. We found a reduced ratio between the expression of the BAX gene and Bcl-XL in the livers of animals with IPC versus the control group. DIPC, RIPC or a combination of both, produce beneficial effects at the molecular level without biochemical or histological changes. [ABSTRACT FROM AUTHOR]

Purpose of the study. To evaluate the dynamics of deformation of spongy application hemostatic materials in an in vitro experiment. Materials and methods. As materials of the study the following samples of hemostatic materials were used: Tachocomb (No. 1), Gelita-Spon Standard (No. 2), Reggicel Fibrillar (No. 3), samples of hemostatic sponges developed jointly with Lintex (St.Petersburg, Russia) on the basis of sodium-Carboxymethyl Cellulose (No. 3): Samples were placed on a glass substrate which was mounted on the rising REM cross-arm 0.2–1 to estimate 50% compression residual strain. A glass substrate rigidly attached to the indenter was mounted so that its lower surface would touch the upper surface of the sample. The crossarm was then lifted at 30 mm/min, compressing the sample until the force reached 50 N, after which the sample was allowed to stand under pressure for 10 seconds. After the load was removed, the sample was removed from the substrate and the compression thickness measured (immediately after compression, after 5, 10 and 30 minutes). Results. The values of the compression residual deformation on the thickness 50% (immediately after the load removal) of the samples of group No. 1 differ statistically significantly from the values of groups No. 2 and No. 3 on 5.92 and 3.51, respectively. The difference between groups No. 1 and No. 4 is 5.61. The ODP values 50% 5 minutes after the load of Group No. 1 samples was removed differ from Groups No. 2 and No. 3 on 5.93 and 3.85, respectively. The difference between groups No. 1 and No. 4 is 6.57. After 30 minutes after compression, the values of the residual deformation of the samples of group No. 1 differ from those of groups No. 2 and No. 3 on 6.9 and 4.3. The difference between groups No. 1 and No. 4 is 6.9. Also, the values of the residual deformation of the samples of group No. 2 exceed the values of the samples of group No. 3 by 1.6 times, and in comparison with group No. 4 is less by 0.03. There are fewer statistical differences with other groups in pilot groups 5–7. Conclusion. The highest values of the indicator "residual deformation at compression by thickness 50%" are noted in group No. 7 (samples based on Na-CMC unpressurized) — 32.34, which causes high mechanical properties of jaws made from this material.

Purpose of the study: Tissue reconstruction after burns, tumor excisions, infections or injuries is a frequent surgical challenge to avoid Ischemia-reperfusion injury. Lazaroids and sildenafil, through their mechanisms of action, have been studied for their protective effects on various organs subjected to IRI. In this study, we aimed to evaluate the therapeutic potential of U-74389G and sildenafil in a swine model of ischemia and reperfusion injury of latissimus dorsi flap. Materials and methods: Forty-two Landrace male pigs, weighing 28–35 kg, were equally (n = 6) randomized into the following groups: (a) Group I: control, (b) Group II: administration of U-74389G after ischemia, (c) Group III: administration of sildenafil after ischemia, (d) Group IV: administration of U-74389G and sildenafil after ischemia, (e) Group V: administration of U-74389G prior to ischemia, (f) Group VI: administration of sildenafil prior to ischemia, and (g) Group VII: administration of U-74389G and sildenafil prior to ischemia. Blood and tissue sampling was conducted before ischemia, 15 and 30 min after occlusion, 30, 60, 90, and 120 min after reperfusion. Results: Statistically significant reduction (p

Microsurgery in itself might be considered a challenge for some plastic surgeons, as it requires patience and perseverance. Furthermore, when it comes to nerve surgery, the challenge is even greater as it implies a longer time necessary to observe results. In clinical practice, a good technique is associated with a good outcome. However, the problem of the recovery time remains an issue to be addressed by future generations. Nerve defects represent an even greater challenge in traumatology. Crush injuries, lacerations and avulsions may all lead to irreversible damage of the nerves. In such cases, special surgery techniques are required to restore function. In order to prepare for these special techniques, a surgeon must begin with experimental in vivo nerve surgery and one that has the highest similarity with humans is the sciatic nerve of the Wistar rat.

Background and AimsPatients with malignant biliary obstruction do not seem to benefit from “two-stage hepatectomy” due to an impairment of liver regeneration. We designed a novel model of “repeated regeneration stimuli” in rats mimicking a “two-stage hepatectomy” with selective or complete biliary occlusion mimicking Klatskin tumors III° or IV°. Using this new model, we wanted to investigate (1) the impact of preexistent cholestasis of different extent on the time course of liver regeneration and (2) the dynamics of hepatobiliary remodeling under regeneration conditions.Materials and MethodsRats were subjected to a sequence of three operations: surgical induction of biliary occlusion, followed by “repeated regeneration stimuli” consisting of ligation of the left branch of the portal vein (supplying 70% of the liver volume, sPVL) as first stage and a 70%-hepatectomy (70%PHx) as second stage. Biliary occlusion (1st procedure) was induced by ligating and transection of either the common (100%, tBDT) or the left bile duct (70%, sBDT). A sham operation without ligating the bile duct was performed as control (0%, Sham). Two weeks later, on day 14 (POD14), the sPVL (2nd procedure) was performed. Another week later (POD 21), the 70%PHx (3rd procedure) took place and animals were observed for 1 week (POD 28). The first experiment (n = 45 rats) was dedicated to investigating liver regeneration (hypertrophy/atrophy), proliferative activity and hepatobiliary histomorphology (2D-histology: HE, BrdU) in the future liver remnant (FLR). The second experiment (n = 25 rats) was performed to study the dynamics of hepatobiliary remodeling in livers with different regenerative pressure (tBDT only POD21 vs. tBDT only POD 28 vs. tBDT + sPVL vs. tBDT + 70%PHx vs. tBDT + sPVL + 70%PHx) using μCT scans of explanted livers.ResultsEffect of biliary occlusionTotal biliary occlusion (tBDT) led to a 2.4-fold increase in whole liver volume due to severe biliary proliferation within 14 days. In contrast, partial biliary occlusion (sBDT) caused only a volume gain of the obstructed liver lobes due to biliary proliferates, resulting in a minor increase of total liver volume (1.7-fold) without an increase in bilirubin levels.Liver regeneration and atrophyAs expected, sPVL caused substantial volume gain (tBDT: 3-fold; sBDT: 2.8-fold; Sham 2.8-fold) of FLR and a substantial volume loss (tBDT: 0.9-fold; sBDT: 0.6-fold; Sham: 0.4-fold) of the portally deprived “future resected lobes” compared to the preoperative liver volume. The subsequent 70%PHx promoted a further volume gain of the FLR in all groups (tBDT: 4-fold; sBDT: 3-fold; Sham 3-fold compared to original volume) until POD 28. Hepatobiliary remodeling: After tBDT, we identified histologically three phases of hepatobiliary remodeling in the FLR. Following tBDT, biliary proliferates developed, replacing about 15% of the hepatocellular tissue. After sPVL we found incomplete restoration of the hepatocellular tissue with a visible reduction of the biliary proliferates. The 70%PHx led to an almost complete recovery of the hepatocellular tissue in the FLR with a nearly normal liver architecture. In contrast, after sBDT and Sham we observed a near normal liver morphology in the FLR at all time points. CT-scanning of the explanted livers and subsequent 3D reconstruction visualized the development of extrahepatic biliary collaterals. Collaterals were detected in 0/5 cases 1 week after sPVL (first regeneration stimulus), and in even more cases (3/5) 1 week after the 70%PHx (second regeneration stimulus). Histological workup identified the typical biliary cuboid epithelium as inner lining of the collaterals and peribiliary glands.ConclusionLiver volume of the FLR increased in cholestatic rats mainly due to biliary proliferates. Application of repeated regeneration stimuli in the style of a “two-stage hepatectomy” promoted almost full restoration of hepatocellular tissue and architecture in the FLR by reestablishing biliary drainage via formation of biliary collaterals. Further exploration of the dynamics in hepatobiliary modeling using this model might help to better understand the underlying mechanism.

Laparoscopic colon surgery is performed frequently in the clinical setting for a multitude of reasons including cancer, infection, and autoimmune disease. As a result, extensive research has been conducted in relation to clinical outcomes after surgery, but more recently, in relation to the impact of surgery and other patient factors on physiologic homeostasis including the host microbiome. Despite this, experimental surgical models for laparoscopic colon surgery are scarce in the literature with most studies utilizing rodents. While rodent studies provide valuable insights into basic mechanistic processes, the translation of novel therapeutic approaches to clinical practice often requires the use of large animal models. In exploring the intricate systems biology linking surgery and medicine, sophisticated models such as nonhuman primates (NHPs) play a pivotal role. By closely resembling human anatomical, physiological, and behavioral characteristics, NHPs facilitate the development and refinement of complex surgical techniques and peri-operative practices. Furthermore, they enable longitudinal studies that comprehensively assess both immediate and long-term outcomes. The availability and utilization of multiple robust models enhance the validity of surgical research, leading to more successful translation to human clinical practice. Here we describe our technique for performing a laparoscopic sigmoid colectomy with a primary anastomosis in an NHP. The entire procedure was well tolerated without significant ventilation or hemodynamic issue. To our knowledge, this represents the first laparoscopic sigmoid colectomy with primary anastomosis performed in an NHP. Furthermore, this demonstrates the feasibility of the technique and provides a relevant, preclinical model for the study of surgical colon disease. Although the surgical colectomy model in NHPs closely resembles the clinical scenario, it is crucial to recognize that a 'model' inherently comes with limitations. The intended use of any model should be carefully evaluated concerning the target patient population with the consideration of potential disparities in anatomy, physiology, environmental factors, and disease to properly interpret results. This model provides an opportunity to study mechanisms, from a systems biology perspective, underlying both innovative surgical treatments and their effects on diseases such as colon cancer, as well as benign conditions like inflammatory bowel disease, diverticulitis, and anastomotic leak, offering high predictive value., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://atm.amegroups.com/article/view/10.21037/atm-24-25/coif). M.L.G. holds the endowed Robert and Katherine Goodale Chair in Minimally Invasive Surgery which was appointed by the Department of Surgery at the University of Minnesota. The endowment is to be used at the Chairperson’s discretion, therefore M.L.G. used it to fund this work. There is no third-party interest. The other authors have no conflicts of interest to declare., (2024 AME Publishing Company. All rights reserved.)

IntroductionFetal amniotic membranes (FM) have been shown to preserve spinal cord histology in the fetal sheep model of myelomeningocele (MMC). This study compares the effectiveness of placenta-derived mesenchymal stromal cells (PMSCs) from early-gestation versus term-gestation placenta to augment FM repair to improve distal motor function in a sheep model.MethodsFetal lambs (n = 4) underwent surgical MMC creation followed by repair with FM patch with term-gestation PMSCs (n = 1), FM with early-gestation PMSCs (n = 1), FM only (n = 1), and skin closure only (n = 1). Histopathology and motor assessment was performed.ResultsHistopathologic analysis demonstrated increased preservation of spinal cord architecture and large neurons in the lamb repaired with early-gestation cells compared to all others. Lambs repaired with skin closure only, FM alone, and term-gestation PMSCs exhibited extremely limited distal motor function; the lamb repaired with early-gestation PMSCs was capable of normal ambulation.DiscussionThis pilot study is the first in vivo comparison of different gestational-age placenta-derived stromal cells for repair in the fetal sheep MMC model. The preservation of large neurons and markedly improved motor function in the lamb repaired with early-gestation cells suggest that early-gestation placental stromal cells may exhibit unique properties that augment in utero MMC repair to improve paralysis.

The impact of COVID-19 in healthcare systems globally was unprecedented leading to cancelations of most planned surgical activities. Surgical trainees were redeployed to Intensive Care and Emergency units supporting urgent and unplanned care on COVID-19 patients. Theater exposure, crucial part of surgical training, was reduced to minimal since elective cases were postponed, and emergency operating was carried out by consultants only. Surgical research has also been severely hit with most of the clinical trials been postponed. Teaching activities as well as national and international congresses and surgical courses important tools for continuous professional development were canceled. The primary aim of our study was to summarize the changes in surgical training during the pandemic. This was followed by a review of the existing social media platforms, video-conferencing platforms along with the role of the social media in surgical training. The crucial role of simulation in surgical training was explored and alternative ways of training with engagement of the feedback mechanisms were proposed. The secondary aim was to highlight possible novel educational strategies for the forthcoming post-COVID-19 era. The "new" era forced the educational boards to reexamine training curriculums. Innovation strategies and cooperation on the part of surgical residency programs is crucial. Strong leadership is needed, on the part of the education bodies with restructuring of the surgical programmes to accommodate alternative ways of training is necessary to maintain rigorous standards of education and training. [ABSTRACT FROM AUTHOR]

Background. Incorporation of a poly-ε-caprolactone (PCL) scaffold in circular stapled anastomoses has been shown to increase the anastomotic tensile strength on postoperative day (POD) 5 in a pig model. The aim of this study was to investigate the effects of incorporation of a PCL scaffold in a circular stapled end-to-end small intestine anastomosis, with stricture formation and anastomotic histology as primary outcomes in a 30-day observation period. Methods. A total of 15 piglets were included. In each piglet, three circular stapled end-to-end anastomoses were made in the small intestines. Two were interventional and one was a control. On POD 10, 20, or 30, the anastomoses were subjected to in vivo intraluminal contrast study, and the index for anastomotic lumen was calculated. The anastomotic segment was resected and subjected to a tensile strength test and histological examination. Results. At POD 10, the mean ± SD value for anastomotic index was.749 ±.065 in control anastomoses and.637 ±.051 in interventional anastomosis (P =.0046), at POD 20,.541 ±.150 and.724 ±.07 (P =.051), and at POD 30,.645 ±.103 and.686 ±.057 (P =.341), respectively. No significant difference was observed in maximum tensile strength and histology at POD 30. Conclusions. The incorporation of a PCL scaffold in a circular stapled end-to-end small intestine anastomosis does not increase the risk of stricture or impair wound healing after 30 days. [ABSTRACT FROM AUTHOR]

Background: Indocyanine green fluorescence imaging (ICG-FI) can be used to evaluate intestinal perfusion prior to anastomosis. Several software for the quantification of fluorescence have emerged, but these have not previously been compared. The aim of this study was to compare the results from quantitative ICG-FI analysis of relative perfusion in an experimental setting using two different software-based quantification algorithms (FLER and Q-ICG). Methods: Twenty pigs received a laparotomy, and ischemic areas were created in three segments of the small intestine of each pig. For each ischemic area, fluorescence imaging was performed and the fluorescence recordings were quantitatively analyzed using FLER and Q-ICG. The quantitative analysis resulted in a set of perfusion lines for each software for either 30%, 60% or 100% relative perfusion. The perfusion lines were compared by registering the normalized slope for each set of perfusion lines, calculating the relative perfusion percentage in the FLER perfusion line according to Q-ICG, and measuring the length of the ischemic area for each analysis. Results: Fifty-four fluorescence recordings from 18 pigs were included. The ischemic segment for FLER was significantly longer in the 30% perfusion group and significantly shorter in the 100% perfusion group as compared to Q-ICG. The normalized slope for the FLER perfusion lines was significantly higher in the 30% perfusion group and significantly lower in the 100% perfusion group as compared to the Q-ICG perfusion lines. For the perfusion lines defined by FLER as 30%, 60%, and 100%, Q-ICG found 35.2% (p = 0.07), 63.7% (p = 0.31), and 84.1% perfusion (p = 0.003) respectively. Conclusion: The two software demonstrated significant differences in quantitative fluorescence analysis when perfusion was either very high or very low. The clinical relevance of these differences is unclear. [ABSTRACT FROM AUTHOR]

Access to the circulatory system is essential for continuous monitoring and long-term experimental study. One of the commonest methods for venous access is femoral vein cannulation. The aim of the presented protocol was to elaborate a surgical model for cannulation of femoral vein in rat. Temporary cannulae such as butterfly needles can be used in short-term procedures, whereas long-term monitoring required surgical implantation of a biocompatible cannula. The protocol allows direct venous access, continuous monitoring and evaluation of the tested compounds in experimental pharmacology and toxicology – the tested compounds reach the systemic circulation immediately and the dose can be accurately titrated against response. The protocol can be applied as an alternative for venous access in experimental clinical settings.

Background and Objectives: Friable or infected tissue remains a challenge in surgical aortic valve replacement. We recently described the “Caput medusae” method, in which circumferential tourniquets temporarily secure the prosthesis and are then gently knotted. Tourniquets have been shown to develop significantly less force than knots. The current study investigates the critical threshold forces for tissue damage to the aortic annulus. Materials and Methods: In 14 fresh porcine hearts, the aortic valve leaflets were removed and several pledgeted sutures were placed along the annulus at defined locations. The hearts were mounted in a self-constructed device. Incremental traction force was applied to every suture and continuously recorded. The movement of each Teflon pledget was filmed with a high-speed camera. Forces at the moment of pledget “cut-in” as well as complete “tear-out” were determined from the recordings. Results: The average threshold force was determined 9.31 ± 6.04 N for cut-in and 20.41 ± 10.02 N for tear-out. Detailed analysis showed that the right coronary region had lower threshold forces than the other regions (4.77 ± 3.28 N (range, 1.67–12.75 N) vs. 10.67 ± 6.04 N (1.62–26.00 N) for cut-in and 10.67 ± 4.04 N (5.40–18.64 N) vs. 23.33 ± 9.42 N (9.22–51.23 N) for tear-out). The findings are discussed in conjunction with the knot and tourniquet forces from our previous study. Conclusions: Even in healthy tissue, moderate forces can reach a critical level at which a Teflon pledget will cut into the annulus, while a complete tear-out is unlikely. The right coronary portion is more susceptible to damage than the remaining regions. When compared to previous data, forces during manual knotting may exceed the critical cut-in level, while rubber tourniquets may provide a higher safety margin against tissue rupture.

Background: Multipotent mesenchymal stromal/stem cell (MSC) therapy is under investigation in promising (pre-)clinical trials for wound healing, which is crucial for survival; however, the optimal cell dosage remains unknown. The aim was to investigate the efficacy of different low-to-high MSC dosages incorporated in a biodegradable collagen-based dermal regeneration template (DRT) Integra®. Methods: We conducted a porcine study (N = 8 Yorkshire pigs) and seeded between 200 and 2,000,000 cells/cm2 of umbilical cord mesenchymal stromal/stem cells on the DRT and grafted it onto full-thickness burn excised wounds. On day 28, comparisons were made between the different low-to-high cell dose groups, the acellular control, a burn wound, and healthy skin. Result: We found that the low dose range between 200 and 40,000 cells/cm2 regenerates the full-thickness burn excised wounds most efficaciously, followed by the middle dose range of 200,000–400,000 cells/cm2 and a high dose of 2,000,000 cells/cm2. The low dose of 40,000 cells/cm2 accelerated reepithelialization, reduced scarring, regenerated epidermal thickness superiorly, enhanced neovascularization, reduced fibrosis, and reduced type 1 and type 2 macrophages compared to other cell dosages and the acellular control. Conclusion: This regenerative cell therapy study using MSCs shows efficacy toward a low dose, which changes the paradigm that more cells lead to better wound healing outcome. [ABSTRACT FROM AUTHOR]

Experimental models with reversible biliary occlusion resulted in a high mortality of the animals, up to 20–60% according to the literature. Our aim was to assess a safe and valid technique for reversible biliary occlusion with a low mortality.

The narrowing of the lumen of the trachea due to cicatricial stenoses of the trachea is one of the urgent problems of the modern surgery. The processes taking place in the trachea and lungs lead to a change in the state of the immune system. Assessment of the dynamics of indices of nonspecific resistance is one of the methods for assessing the severity of the course of the disease. We studied the indices of nonspecific resistance of the organism in narrowing the lumen of the trachea in an experiment in the early postoperative period. The study was carried out on the basis of the scientific department of experimental surgery with the vivarium of Irkutsk Scientific Centre of Surgery and Traumatology, on 24 white male Wistar rats with a body weight of 300–350 g. We simulated narrowing the lumen of the trachea by placing a silicone tube in the lumen of the trachea for 14 days. The parameters of phagocytosis, the state of phagocytic activity of blood neutrophils, spontaneous NBT-test, induced NBT- test were studied. The animals were withdrawn from the experiment on the 3rd, 7th and 14th day. We revealed that as a result of narrowing of the lumen of the trachea with the original procedure, the nonspecific resistance of the organism was violated with inhibition of the phagocytic activity of leukocytes. There was inhibition of phagocytic activity of leukocytes and depletion of the functional reserve of leukocytes.

Objective: To Present the implementation of the first porcine model of liver transplant in Chile and its results. Materials and Methods: In the context of an investigation based on normothermic perfusion that was subsidized by the National Fund for Scientific and Technological Development, surgical and anesthetic protocols were implemented. Two pigs were selected by weight (35-40 kg), in which one was a donor and the other a receptor; submitted to procure and as a transplant recipient, respectively. The analysis was executed with descriptive statistics. Results: 26 experiments (June 2018-October 2019) were performed. The protocol includes 7 stages: Preparation, Instrumentalization, Procure or Hepatectomy, Anhepatic Time, Phase of Ischemia-Reperfusion, Monitoring and Euthanasia. The first three stages are similar in both pigs; meanwhile the last four are exclusive to the receptor. 92.3% (24/26) survived the surgery and 76.9% (20/26) survived the follow up, including the pilots. Average surgical time was 170 minutes, and the anhepatic time was 33 minutes. The mean arterial pressure decreased after the reperfusion and it improved towards the end of the monitorization (67,4 mmHg average) In the follow up, pigs presented acidosis (7.21 average). Vasoactive drugs were necessary in 12 experiments. Discussion: We managed to implement a simple and reproducible model of porcine liver transplant without extracorporeal circulation or venovenous by-pass. This was possible due to the standardization of surgical technique and perioperative cares. Conclusions: The consolidation of porcine liver transplant model is the first step in pre-clinical research for the development of new technologies in liver transplant in Chile. [ABSTRACT FROM AUTHOR]

Experimental preclinical surgeries require high accuracy and repeatability in all applied procedures. For in vivo studies investigating bone fracture healing it is crucial to create precisely and consistently the experimental bone fractures in all included subjects. In large animal models the required precision is usually achieved by application of dedicated drilling jigs and cutting guides that often need to be individually designed in order to fulfil the requirements of a particular experiment. Moreover, their final design may considerably differ from the prototypes. Hence, the designing and testing processes require multiple iterative refinement loops substantially increasing the costs of the experiment. Therefore, a framework for development of tailor-made instruments for experimental preclinical surgeries is established to reduce the investment of time and financial effort. [ABSTRACT FROM AUTHOR]

Vascular access ports (VAPs) are an essential tool for long-term vascular access in preclinical studies and disease modeling in non-human primates (NHPs). We retrospectively reviewed central (inferior vena cava, IVC) and portal VAP implantation with the maintenance at our center from 15 January 2010 to 31 January 2018. In total, 209 VAPs were implanted for long-term drug administration and sampling. Patency was >95% at 6 months and >80% at 1 year for IVC VAPs and >90% at 6 months and >85% at 1 year for portal VAPs. The majority of animals had no complications and access was generally durable with device use ranging up to 7 years. In IVC, VAPs loss of patency occurred in 13% (0.035/100 d), surgical site infection in 2.9% (0.097/100 d), port pocket infection in 2.2% (0.004/100 d), erosion in 2.9%, 0.008/100 d), and mechanical failure in 4.3% (0.012/100 d). In portal, VAPs loss of patency occurred in 11.3% (0.028/100 d) and port pocket infection in 1.4% (0.003/100 d). About 12% of VAPs were removed as a result of complications. This study confirms VAP implant and maintenance is a beneficial and safe practice in NHPs resulting in favorable outcomes. High patency rates and low complication rates are comparable to the clinical setting. In addition to enabling comprehensive data collection, VAPs increase satisfaction and well-being by minimizing interference with daily routines and fostering cooperation. VAP implantation, together with an effective maintenance regimen and co-operative handling, is a reliable and convenient refined method for drug administration and blood sampling. [ABSTRACT FROM AUTHOR]

Astley Paston Cooper (1768-1841) was presumably the most prominent English surgeon and anatomist of the early decades of the 19th century who promoted the experimental surgery on animals, the significance of cadaveric dissection in surgery and the value of the observation and physiological knowledge for every surgeon. Becoming very early at the age of 23 lecturer on anatomy and surgery at St. Thomas's Hospital, Cooper was devoted to surgery in an era where no anesthesia and antisepsis existed, as well to anatomy and experimental surgery. First of all, he performed ligation of common carotid artery and abdominal aorta for aneurysms, resection of the contracture of the palmar aponeurosis prior to Dupuytren, whereas he contributed to advance of the hernias' and breast surgery. He was among the first surgeon in Europe that incorporated surgery to medicine, whilst his brilliant surgical teaching inspired generations of surgeons in Europe at the early 19th century. [ABSTRACT FROM AUTHOR]

Purpose of the study: Tissue reconstruction after burns, tumor excisions, infections or injuries is a frequent surgical challenge to avoid Ischemia-reperfusion injury. Lazaroids and sildenafil, through their mechanisms of action, have been studied for their protective effects on various organs subjected to IRI. In this study, we aimed to evaluate the therapeutic potential of U-74389G and sildenafil in a swine model of ischemia and reperfusion injury of latissimus dorsi flap. Materials and methods: Forty-two Landrace male pigs, weighing 28–35 kg, were equally (n = 6) randomized into the following groups: (a) Group I: control, (b) Group II: administration of U-74389G after ischemia, (c) Group III: administration of sildenafil after ischemia, (d) Group IV: administration of U-74389G and sildenafil after ischemia, (e) Group V: administration of U-74389G prior to ischemia, (f) Group VI: administration of sildenafil prior to ischemia, and (g) Group VII: administration of U-74389G and sildenafil prior to ischemia. Blood and tissue sampling was conducted before ischemia, 15 and 30 min after occlusion, 30, 60, 90, and 120 min after reperfusion. Results: Statistically significant reduction (p < 0.05) was detected in lymphocytes and polymorphonuclear leukocytes concentrations as well as in the appearance of edema after histopathologic evaluation of the ischemic tissue, especially in the groups of combined treatment. Measurements of malondialdeyde and tumour necrosis factor alpha in tissues revealed a significant decrease (p < 0.001) of these markers in the treatment groups when compared to the control, particularly in the latest estimated timepoints. Conclusions: The synergistic action of U-74389G and sildenafil seems protective and promising in cases of flap IRI during tissue reconstruction surgery. [ABSTRACT FROM AUTHOR]

Microsurgery in itself might be considered a challenge for some plastic surgeons, as it requires patience and perseverance. Furthermore, when it comes to nerve surgery, the challenge is even greater as it implies a longer time necessary to observe results. In clinical practice, a good technique is associated with a good outcome. However, the problem of the recovery time remains an issue to be addressed by future generations. Nerve defects represent an even greater challenge in traumatology. Crush injuries, lacerations and avulsions may all lead to irreversible damage of the nerves. In such cases, special surgery techniques are required to restore function1-4. In order to prepare for these special techniques, a surgeon must begin with experimental in vivo nerve surgery and one that has the highest similarity with humans is the sciatic nerve of the Wistar rat5. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate histologically the root surfaces of teeth submitted to orthodontic and surgical extrusion procedures in a dog model. Eighteen adult male dogs, divided into six groups of three dogs each, were used in the study. Each animal underwent two procedures: rapid orthodontic extrusion and surgical extrusion of the maxillary lateral incisors. The animals were sacrificed to produce samples at 7, 14, 45, 90, 120, and 180 days after surgery for assessment of cross sections of the coronal, medial, and apical thirds of the treated teeth. At early time points, some active surface and inflammatory resorption was observed exclusively in the surgical extrusion group; however, samples collected at later times demonstrated functional repair of the resorption gaps in both groups. Ankylosis was observed as a minor event and was apparently of a transient nature in samples of the surgical extrusion group. The results demonstrate the importance of maintaining the periodontal ligament and cementum surface; both are vital for the prevention of root resorption. It may be postulated that orthodontic extrusion is more conservative and physiologic than surgical extrusion; however, the results showed that function was restored in both groups. [ABSTRACT FROM AUTHOR]

When learning the basics of microsurgery, a trainee must be equipped with patience and perseverance in order to evolve. One must have the ground knowledge when it comes to peripheral nerve injury and nerve regeneration process in order to fully understand that the technique is vital for the outcome and final results. Furthermore, a trainee must practice on non-living tissue before performing successful in vivo operations and even in this case, one may be confronted with problems regarding the surgical technique. [1] The following article aims to reveal the main problems/mistakes when performing sciatic nerve surgery in an in vivo experimental model and the solutions for these problems.

When learning the basics of microsurgery, a trainee must be equipped with patience and perseverance in order to evolve. One must have the ground knowledge when it comes to peripheral nerve injury and nerve regeneration process in order to fully understand that the technique is vital for the outcome and final results. Furthermore, a trainee must practice on non-living tissue before performing successful in vivo operations and even in this case, one may be confronted with problems regarding the surgical technique. [1] The following article aims to reveal the main problems/mistakes when performing sciatic nerve surgery in an in vivo experimental model and the solutions for these problems. [ABSTRACT FROM AUTHOR]