BACKGROUND: Endoscopic sphincterotomy (EST) is widely used to treat common bile duct stones (CBDS); however, long-term studies have revealed the increasing incidence of recurrent CBDS after EST. Loss of sphincter of Oddi function after EST was the main cause of recurrent CBDS. Reparation of the sphincter of Oddi is therefore crucial. This study aims to investigate the effectiveness and safety of endoclip papilloplasty (ECPP) for repairing the sphincter of Oddi and elucidate its mechanism. METHODS: Eight healthy Bama minipigs were randomly divided into the EST group and the ECPP group at a 1:1 ratio, and bile samples were collected before endoscopy and 6 months later. All minipigs underwent transabdominal biliary ultrasonography for the diagnosis of cholelithiasis 6 months after endoscopy. The biliary microbiota composition and alpha and beta diversity were analyzed by 16S ribosomal RNA gene sequencing. Differential metabolites were analyzed by bile acid metabolomics to explore the predictive indicators of cholelithiasis. RESULTS: Three minipigs were diagnosed with cholelithiasis in the EST group, while none in the ECPP group showed cholelithiasis. The biliary Firmicutes/Bacteroidota (F/B) ratio was increased after EST and decreased after ECPP. The Chao1 and observed species index significantly decreased 6 months after EST ( P  = 0.017 and 0.018, respectively); however, the biliary α-diversity was similar before and 6 months after ECPP. The β-diversity significantly differed in the EST group before and 6 months after EST, as well as in the ECPP group before and 6 months after ECPP (analysis of similarities [ANOSIM]: R  = 0.917, P  = 0.040; R  = 0.740, P  = 0.035; respectively). Glycolithocholic acid (GLCA) and taurolithocholic acid (TLCA) accumulated in bile 6 months after EST. CONCLUSIONS ECPP has less impact on the biliary microenvironment than EST and prevents duodenobiliary reflux by repairing the sphincter of Oddi. The bile levels of GLCA and TLCA may be used to predict the risk of cholelithiasis.
Animals ; Swine, Miniature ; Swine ; Cholelithiasis/prevention & control* ; Sphincterotomy, Endoscopic/methods* ; Sphincter of Oddi/surgery* ; Female ; Male

OBJECTIVE: To investigate the effects of bone density, plate bending degree and proximal screw type on the stress fracture of clavicle hook. METHODS: Three sows weighing between 45 and 50 kg were selected, from which a total of 40 rivs were collected. The 15 ribs of sows were divided into 3 groups according to bone density and bone hardness with 5 rivs in each group. And then the 3 groups were fixed with 6-hole collarbone hook plates and 3 locking screws. Measure the maximum torsion force when the ribs were fractured by force. The same size 15 rids were divided into 3 groups, named forward bending group, 0° group(the angle between the plate surface and the rib surface) and reverse bending group. All fixed with 6-hole collarbone hook plates and locking screws to measure the maximum torsion force of rib stress fracture. Then the same size 10 rids were divided into 2 groups, the normal screw group and the locking screw group with 5 ribs in each group. Both groups were fixed with 6-hole collarbone hook plates and screws. The normal screw group was a normal screw, fixed in proximal end, and two locking screws. The locking screw group was fixed by locking screws. Measure the maximum torsion force of the two groups when the ribs fracture by force. RESULTS: In the bone density experiment, the torque force of hard bone group (104.51±6.27) N was greater than the normal bone group (75.04±3.81) N(t=8.979, P<0.05). The force of normal bone group was greater than the osteoporosis group (49.99±2.12) N(t=12.832, P<0.05). In the bending collarbone hook experiment, the order of the torque force generated by each group as follow:the forward bending group (343.59±6.18) N greater than the 0° group (106.01±5.29) N(t=65.279, P<0.05) greater than the reverse bending group (95.82±4.12) N(t=3.398, P<0.05). The force of the normal screw group (98.68±0.70) N was greater than the locking screw group (50.20±0.95) N(t=91.484, P<0.05). The data comparisons of each group were statistically significant. CONCLUSION Bone density, plate bending degree and proximal screw type had an impact on stress fracture of clavicle hook plate. Higher bone density, forward bending of the steel plate, and ordinary screws in proximal end can reduce the rates of stress fractures of clavicle hooks.
Animals ; Bone Plates ; Clavicle/surgery* ; Swine ; Fractures, Stress/etiology* ; Female ; Risk Factors ; Fracture Fixation, Internal/instrumentation* ; Bone Screws ; Biomechanical Phenomena ; Bone Density

To address the limitations of traditional minimally invasive thermal ablation technology such as poor conformability, carbonization and electromagnetic radiation, this paper proposes a steam thermal ablation technology that uses saturated steam internal energy to replace the traditional electromagnetic radiation energy. Through the steam thermal ablation system and the steam thermal ablation needle designed based on simulation, the ex vivo pig liver experiments were carried out. The results have the characteristics of the maximum ablation axis ratio (short diameter / long diameter) and non-carbonization with the same type of thermal ablation technology. Based on the near-infrared light, in this paper the curative effect of the reduced scattering coefficient of the steam thermal ablation results was evaluated. The reduced scattering coefficients of the coagulation area all exceeded 16, reaching the completely damaged state, which verified that the steam thermal ablation can effectively inactivate the tumor cells.
Steam ; Animals ; Swine ; Liver Neoplasms/surgery* ; Ablation Techniques/methods* ; Liver/surgery* ; Equipment Design

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

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

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

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

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*

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: 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