PURPOSE: To develop animal models of penetrating thoracic injuries and to observe the effects of the animal model-based training on improving the trainees' performance for emergent and urgent thoracic surgeries. METHODS: With a homemade machine, animal models of lung injuries and penetrating heart injuries were produced in porcine and used for training of chest tube drainage, urgent sternotomy, and emergent thoracotomy. Coefficient of variation of abbreviated injury scale and blood loss was calculated to judge the reproducibility of animal models. Five operation teams from basic-level hospitals (group A) and five operation teams from level III hospitals (group B) were included to be trained and tested. Testing standards for the operations were established after thorough literature review, and expert questionnaires were employed to evaluate the scientificity and feasibility of the testing standards. Tests were carried out after the training. Pre- and post-training performances were compared. Post-training survey using 7-point Likert scale was taken to evaluate the feelings of the trainees to these training approaches. RESULTS: Animal models of the three kinds of penetrating chest injuries were successfully established and the coefficient of variation of abbreviated injury scale and blood loss were all less than 25%. After literature review, testing standards were established, and expert questionnaire results showed that the scientific score was 7.30 ± 1.49, and the feasibility score was 7.50 ± 0.89. Post-training performance was significantly higher in both group A and group B than pre-training performance. Post-training survey showed that all the trainees felt confident in applying the operations and were generally agreed that the training procedure were very helpful in improving operation skills for thoracic penetrating injury. CONCLUSIONS Animal model-based simulation training established in the current study could improve the trainees' performance for emergent and urgent thoracic surgeries, especially of the surgical teams from basic-level hospitals.
Animals ; Swine ; Reproducibility of Results ; Wounds, Penetrating/surgery* ; Thoracotomy ; Thoracic Injuries/surgery* ; Hemorrhage ; Models, Animal

OBJECTIVE: To investigate the repair method of type Ⅱc injury in the lateral meniscus popliteal tendon area based on the porcine knee joint. METHODS: Eighteen commercially available fresh porcine knee joints were randomly divided into 3 groups ( n=6). After preparing a type Ⅱc injury in the lateral meniscus popliteal tendon area, and the anterior (group A), posterior (group B), or anterior and posterior (group C) of the popliteal hiatus (PH) was sutured by vertical mattress. The tension meter was used to apply gradient tensions of 2, 4, 6, 8, and 10 N along the tibial plateau horizontally, respectively, to pull the midpoint of the lateral meniscus popliteal tendon area. The displacement values before modeling, after modeling, and after suture were recorded. The reduction value of lateral meniscus displacement and reduction rate after suture were calculated and compared between groups. RESULTS: There was no significant difference between groups ( P>0.05) in the displacement values before modeling, after modeling, and after suture under different tensions. There was no significant difference between groups A and C ( P>0.05) in the reduction value of lateral meniscus displacement and reduction rate after suture under different tensions. The reduction value of lateral meniscus displacement and reduction rate after suture in group B were lower than those in groups A and C. The reduction value of lateral meniscus displacement under tension of 2 N and the reduction rates under tensions of 2, 4, and 6 N between groups A and B showed significant differences ( P<0.05). The reduction value of lateral meniscus displacement and the reduction rate under tensions of 2, 4, and 6 N between groups B and C showed significant differences ( P<0.05). CONCLUSION Suturing the anterior area of PH is the key to repairing type Ⅱc injury of lateral meniscus popliteal tendon area.
Animals ; Humans ; Knee ; Knee Joint ; Menisci, Tibial/surgery* ; Swine ; Tendons ; Tibia

Objective: To explore the performance of a self-made venous-venous bypass (VVB) device for liver transplantation based on the principle of magnetic levitation drive. Methods: Experimental study was conducted from August 2020 to January 2022. Eight Bama minipigs underwent VVB of hepatic portal vein-femoral vein-internal jugular vein after occlusion of hepatic portal vein and inferior vena cava. The animals were divided into two groups according to the VVB devices used during VVB. A self-made VVB device was used in group A(n=5),and an imported VVB device was used in group B(n=3). The hemodynamic changes of the two groups of animals were compared at 6 time points including before vascular occlusion, during vascular occlusion, 30 minutes, 60 minutes, 90 minutes after the start of VVB, and 30 minutes after vascular opening. In addition,the changes of blood compatibility indexes,intestinal injury indexes,kidney injury indexes and internal environment indexes of the two groups of animals at each time point were compared. The independent samples t test was used for the quantitative data between the two groups with non-repeated measures,and the repeated measures analysis of variance was used for the quantitative data between the two groups with repeated measures. Results: During the VVB of the two devices,the venous drainage was sufficient,and the main manifestations were that the color of the intestine of the Bama miniature pig was ruddy, the peristalsis was normal, and the urine output was normal. There were no significant differences in hemodynamics,blood injure indexes,intestinal injury indexes,kidney injury indexes,neutropil gelatinase-associated lipocalin,and internal environment indexes(all P>0.05).The indexes at 30 minutes after vascular opening in the group A and the group B were as follows:mean arterial pressure were (71.0±7.7)mmHg(1 mmHg=0.133 kPa) and (74.0±8.7)mmHg,central venous pressure were (7.0±1.4)cmH₂O(1 cmH₂O=0.098 kPa) and (7.7±0.6)cmH₂O,heart rate were (131±10) beats/minutes and (132±8)beats/minutes; red blood cell count were (6.43±0.89)×10¹²/L and (6.32±0.58)×10¹²/L,hemoglobin were (108.4±5.9)g/L and (110.0±3.5)g/L,free hemoglobin were (78.28±3.96)mg/L and (78.08±4.54)mg/L; intestinal fatty acid binding protein were (2.27±0.49)μg/L and (2.40±0.78)μg/L;creatinine were (68.30±9.77)μmol/L and (79.90±26.91)μmol/L,blood urea nitrogen were (3.94±1.39)mmol/L and (3.45±0.65)mmol/L;neutropil gelatinase-associated lipocalin were (4.02±0.53) μg/L and (3.86±0.23)μg/L;pH value were 7.27±0.04 and 7.23±0.03,lactic acid were (6.18±2.62)mmol/L and (4.30±0.50)mmol/L,concentrations of Na⁺ were (136.3±3.0)mmol/L and (137.6±1.6) mmol/L,concentrations of K⁺ were (3.89±0.42) mmol/L and (3.98±0.17)mmol/L,concentrations of Ca²⁺ were (1.40±0.03)mmol/L and(1.40±0.04)mmol/L;all indexes in the two group had no differences(all P>0.05). Conclusion: The self-made venous bypass device can be safely and effectively applied to VVB of Bama minipigs,and achieves the same performance as the imported venous bypass device.
Animals ; Creatinine ; Fatty Acid-Binding Proteins ; Gelatinases ; Lactic Acid ; Lipocalins ; Liver Transplantation ; Magnetic Phenomena ; Portal Vein/surgery* ; Swine ; Swine, Miniature

In the recent years, the shortage of allo-skin sources has resulted in great challenges for salvage of patients with large area severe burns. Although being similar to human skin in construction and function, the clinical application of xenogenic porcine skin in burn wound management is limited due to factors including immuno-rejection, porcine endogenous retroviruses infection, etc. With the development of gene editing technology, especially the emerge of clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein-9 system, multiple target genes could be possibly edited at the same time, which will bring broad prospect for the application of xenogenic porcine skin in the treatment of burn wounds. The paper mainly discusses the development, the existed barrier, the strategies of gene modification/editing, and the applications and research of xenogenic porcine skin xenografts in the clinical treatment of burn wound.
Animals ; Burns/surgery* ; CRISPR-Associated Proteins ; Clustered Regularly Interspaced Short Palindromic Repeats ; Gene Editing ; Humans ; Skin Transplantation/methods* ; Swine

BACKGROUND: High-frequency irreversible electroporation (H-FIRE) is a novel, next-generation nanoknife technology with the advantage of relieving irreversible electroporation (IRE)-induced muscle contractions. However, the difference between IRE and H-FIRE with distinct ablation parameters was not clearly defined. This study aimed to compare the efficacy of the two treatments in vivo. METHODS: Ten Bama miniature swine were divided into two group: five in the 1-day group and five in the 7-day group. The efficacy of IRE and H-FIRE ablation was compared by volume transfer constant (Krans), rate constant (Kep) and extravascular extracellular volume fraction (Ve) value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), size of the ablation zone, and histologic analysis. Each animal underwent the IRE and H-FIRE. Temperatures of the electrodes were measured during ablation. DCE-MRI images were obtained 1, 4, and 7 days after ablation in the 7-day group. All animals in the two groups were euthanized 1 day or 7 days after ablation, and subsequently, IRE and H-FIRE treated liver tissues were collected for histological examination. Student's t test or Mann-Whitney U test was applied for comparing any two groups. One-way analysis of variance (ANOVA) test and Welch's ANOVA test followed by Holm-Sidak's multiple comparisons test, one-way ANOVA with repeated measures followed by Bonferroni test, or Kruskal-Wallis H test followed by Dunn's multiple comparison test was used for multiple group comparisons and post hoc analyses. Pearson correlation coefficient test was conducted to analyze the relationship between two variables. RESULTS: Higher Ve was seen in IRE zone than in H-FIRE zone (0.14 ± 0.02 vs. 0.08 ± 0.05, t = 2.408, P = 0.043) on day 4, but no significant difference was seen in Ktrans or Kep between IRE and H-FIRE zones at all time points (all P > 0.05). For IRE zone, the greatest Ktrans was seen on day 7, which was significantly higher than that on day 1 (P = 0.033). The ablation zone size of H-FIRE was significantly larger than IRE 1 day (4.74 ± 0.88 cm2vs. 3.20 ± 0.77 cm2, t = 3.241, P = 0.009) and 4 days (2.22 ± 0.83 cm2vs. 1.30 ± 0.50 cm2, t = 2.343, P = 0.041) after treatment. Apoptotic index (0.05 ± 0.02 vs. 0.73 ± 0.06 vs. 0.68 ± 0.07, F = 241.300, P < 0.001) and heat shock protein 70 (HSP70) (0.03 ± 0.01 vs. 0.46 ± 0.09 vs. and 0.42 ± 0.07, F = 64.490, P < 0.001) were significantly different between the untreated, IRE and H-FIRE zones, but no significant difference was seen in apoptotic index or HSP70 between IRE and H-FIRE zone (both P > 0.05). Electrode temperature variations were not significantly different between the two zones (18.00 ± 3.77°C vs. 16.20 ± 7.45°C, t = 0.682, P = 0.504). The Ktrans value (r = 0.940, P = 0.017) and the Kep value (r = 0.895, P = 0.040) of the H-FIRE zone were positively correlated with the number of hepatocytes in the ablation zone. CONCLUSIONS H-FIRE showed a comparable ablation effect to IRE. DCE-MRI has the potential to monitor the changes of H-FIRE ablation zone.
Animals ; Contrast Media ; Electroporation ; Follow-Up Studies ; Liver/surgery* ; Magnetic Resonance Imaging ; Swine

OBJECTIVE: To compare biomechanical characteristic of different high-strength sutures and suture sites for repairing posterior root tear of the medial meniscus with modified Mason-Allen technique. METHODS: Forty-eight specimen of medial meniscus of knee joint from fresh porcine (female, aged from 5 to 9 months with an average of 7 months) were chosen and established experimental model. The samples were divided into red zone fixation group and red-white zone fixation group according to suture sites, 24 in each group; and then were randomly divided into 3 subgroups which 8 in each group, and fixed with Ethibond suture, Ultrabraid suture and FiberWire suture, respectively. Biomechanical tests were performedon universal electromagnetic and mechanical testing machine. Each specimen was underwent 1 000 cyclic tests on the first time, then pull out test until failure. The maximum failure load, yield load, stiffness and displacement were analyzed. RESULTS: All specimen were successfully completed biomechanical tests. The failure mode of Ethibond group was caused by suture fracture; 6 cases of Ultrabraid suture group was caused by suture fracture which belong to red zone fixation group, 10 cases were caused by suture pull out, which 2 cases belong to red zone fixation group, 8 cases belong to red-white zone fixation group;8 cases of FiberWire group was caused by suture pull-out. Biomechanical test showed that:(1)In terms of suture strength, comparison of the maximum failure load, yield load and stiffness showed that Ethibond suture group CONCLUSION Mason-Allen suture could effectively fix posterior root tear of the medial meniscus and meet needs of early partial weight bearing after surgery. Suturing with Fiberwire in red zone is stronger and better for the meniscus healing and rehabilitation.
Animals ; Biomechanical Phenomena ; Female ; Menisci, Tibial/surgery* ; Rupture/surgery* ; Suture Techniques ; Sutures ; Swine

BACKGROUND: Multiple techniques are commonly used for posterior cruciate ligament (PCL) reconstruction. However, the optimum method regarding the fixation of PCL reconstruction after PCL tears remains debatable. The purpose of this study was to compare the biomechanical properties among three different tibial fixation procedures for transtibial single-bundle PCL reconstruction. METHODS: Thirty-six porcine tibias and porcine extensor tendons were randomized into three fixation study groups: the interference screw fixation (IS) group, the transtibial tubercle fixation (TTF) group, and TTF + IS group (n = 12 in each group). The structural properties of the three fixation groups were tested under cyclic loading and load-to-failure. The slippage after the cyclic loading test and the stiffness and ultimate failure load after load-to-failure testing were recorded. RESULTS: After 1000 cycles of cyclic testing, no significant difference was observed in graft slippage among the three groups. For load-to-failure testing, the TTF + IS group showed a higher ultimate failure load than the TTF group and the IS group (876.34 ± 58.78 N vs. 660.92 ± 77.74 N [P < 0.001] vs. 556.49 ± 65.33 N [P < 0.001]). The stiffness in the TTF group was significantly lower than that in the IS group and the TTF + IS group (92.77 ± 20.16 N/mm in the TTF group vs. 120.27 ± 15.66 N/m in the IS group [P = 0.001] and 131.79 ± 17.95 N/mm in the TTF + IS group [P < 0.001]). No significant difference in the mean stiffness was found between the IS group and the TTF + IS group (P = 0.127). CONCLUSIONS In this biomechanical study, supplementary fixation with transtibial tubercle sutures increased the ultimate failure load during load-to-failure testing for PCL reconstruction.
Animals ; Biomechanical Phenomena ; Posterior Cruciate Ligament Reconstruction ; Sutures ; Swine ; Tendons/surgery* ; Tibia/surgery*

In order to study the mechanical behavior of degeneration and nucleotomy of lumbar intervertebral disc, compression experiments with porcine lumbar intervertebral discs were carried out. The lumbar intervertebral discs with trypsin-treated and nucleus nucleotomy served as the experimental group and the normal discs as the control group. Considering the effects of load magnitude and loading rate, the relationship between stress and strain, instantaneous elastic modulus and creep property of intervertebral disc were obtained. The creep constitutive model was established. The results show that the strain and creep strain of the experimental group increase significantly with the increase of compression load and loading rate, whereas the instantaneous elastic modulus decreases obviously, compared with the control group. It indicates that the effect of load magnitude and loading rate on load-bearing capacity of intervertebral disc after nucleotomy is larger obviously than that of normal disc. The creep behavior of the experimental group can be still predicted by the Kelvin three-parameter solid model. The results will provide theoretical foundation for clinical treatment and postoperative rehabilitation of intervertebral disc disease.
Animals ; Biomechanical Phenomena ; Intervertebral Disc ; physiology ; surgery ; Lumbar Vertebrae ; Stress, Mechanical ; Swine ; Weight-Bearing

OBJECTIVETo observe the safety and efficacy of biological patch (Biodesign Surgisis mesh, SIS) in hybrid technique for incisional herniorrhaphy.

METHODSClinical and follow-up data of 14 incisional hernia patients who underwent incisional herniorrhaphy with hybrid technique, using porcine small intestinal submucosa acellular matrix patch, at the First Affiliated Hospital of Sun Yat-sen University from January 1, 2012 to June 31, 2016 were analyzed retrospectively. This Biodesign Surgisis patch for incisional hernia is produced by the Cook company in the United States. The size of patch ranged from 9 cm × 15 cm to 20 cm × 25 cm. During operation, according to abdominal wall defect, the patch was cut to ensure the distance from its edge to the border of abdominal wall defect more than 5 cm.

RESULTSThere were four male and tenfemale patients with average age of (67.7±11.6) years and average body mass index(BMI) of (25.5±1.7) kg/m². As for operative history of these 14 cases, 7 cases had gastrointestinal tumor surgery, 2 had appendectomy, 1 had upper abdominal white line hernia repair, 1 had hysterectomy, 1 had cholecystectomy, 1 had splenectomy plus portal vein dissection, and 1 had right kidney and right ureter total resection plus partial excision of bladder wall. Ten casesdeveloped incisional infection after previous surgery. The duration of incisional hernia ranged 1 to 180 months (median, 8 months). Two cases were refractory hernia, 1 was incarcerated hernia, and 11 were reversible hernia. The locations of incisional hernia included 4 cases of right ventral wall, 1 case of left ventral wall, 2 cases of supra-umbilical incision, 4 cases of infra-umbilical midline incision, and 3 cases of peri-umbilical midline incision. There were 3 cases of middle incisional hernia, 5 cases of large incisional hernia and 6 cases of huge incisional hernia. All the patients completed operations eventlessly. The average operative time was (202.5±72.9) minutes. The average length and width of hernia ring were (10.9±4.3) cm and (9.3±3.9) cm, respectively. Clean operation was performed in 11 cases, potential contaminative operation in 2 cases and contaminative operation in 1 case. The amount of operative bleeding was (15.0±4.8) ml. The NRS pain scores within 24 hours after the operation, at POD3 and at POD7 were 5.1±0.9, 4.2±0.7 and 3.7±0.9, respectively. The time to flatus after operation was (2.5±0.9) days and the time to liquid diet was (3.8±1.2) days. No patient died during the perioperative period. The average hospitalization time was (21.5±12.0) days. Postoperative complications occurred in 8 cases, including 4 cases of fever, 8 cases of incision complications, 4 cases of abdominal infection, 4 cases of intestinal obstruction, 5 cases of effusion under patch, 2 cases of pneumonia, and 1 case of acute myocardial infarction. According to the Clavien-Dindo classification, 3 cases were grade zero, 3 cases were grade I(, 6 cases were grade II(, 1 case was grade III(, and 1 case was grade IIII(. Thirteen patients received follow-up and the average follow-up time was (33.2±12.3) (18.2-61.0) months. One patient died of cerebral infarction 38 months after operation. The chronic abdominal pain or discomfort was found in 4 cases. The recurrent incisional hernia developed in 5 cases and the average time of recurrence was (11.0±8.3) months.

CONCLUSIONSBiological patch can be used safely and effectively in hybrid technique for incisional herniorrhaphy. However, the morbidity of postoperative complication and the risk of recurrence are high. Terefore, the long-term outcome is still subject to observation.

Aged ; Animals ; Bioprosthesis ; Female ; Follow-Up Studies ; Hernia, Ventral ; surgery ; Herniorrhaphy ; Humans ; Male ; Middle Aged ; Postoperative Complications ; Recurrence ; Retrospective Studies ; Surgical Mesh ; Swine

PURPOSE: Adequate hemostasis is important for postoperative outcomes of abdominal surgery. This study evaluated the hemostatic effects and accompanying histopathological changes of a novel oxidized regenerated cellulose, SurgiGuard®, during abdominal surgery. MATERIALS AND METHODS: Ten pigs underwent wedge resection of the spleen (1×1 cm) and liver (1.5×1.5 cm). The resected surface was covered with Surgicel® fabric or fibril type (Group A) or SurgiGuard® fabric or fibril type (Group B). Surgicel® and SurgiGuard® were randomized for attachment to the resected surface by fabric type (n=5) or fibril type (n=5). Blood loss was measured 5, 7, and 9 min after resection. Pigs were necropsied 6 weeks postoperatively to evaluate gross and histopathological changes. RESULTS: There was no significant difference in total blood loss between groups [spleen fabric: Group A vs. Group B, 4.38 g (2.74–6.43) vs. 3.41 g (2.46–4.65), p=0.436; spleen fibril: Group A vs. Group B, 3.44 g (2.82–6.07) vs. 3.60 g (2.03–6.09), p=0.971; liver fabric: Group A vs. Group B, 4.51 g (2.67–10.61) vs. 6.93 g (3.09–9.95), p=0.796; liver fibril: Group A vs. Group B, 3.32 g (2.50–8.78) vs. 3.70 g (2.32–5.84), p=0.971]. Histopathological analysis revealed no significant difference in toxicities related to Surgicel® or SurgiGuard® [inflammation, fibrosis, foreign bodies, and hemorrhage (spleen: p=0.333, 0.127, 0.751, and 1.000; liver: p=0.155, 0.751, 1.000, and 1.000, respectively)]. CONCLUSION: SurgiGuard® is as effective and non-toxic as Surgicel® in achieving hemostasis after porcine abdominal surgery.
Animals ; *Blood Loss, Surgical/statistics & numerical data ; Cellulose, Oxidized/*therapeutic use ; Hemostasis, Surgical/*methods ; Hemostatics/*therapeutic use ; Liver/*surgery ; Random Allocation ; Spleen/*surgery ; Swine