BACKGROUND: Ligament Advanced Reinforcement Sytstm (LARS) artificial ligament can avoid the interfibrillar friction compared wiht traditional ligaments, which is conductive for autogenous tissue growth. OBJECTIVE: To investigate the biocompatibility of LARS artificial ligament used for cruciate ligament reconstruction and bone healing. METHODS: Twenty goats were randomly divided into two groups: the anterior cruciate ligament insertion at the femur was cut as stump group; the anterior cruciate ligament insertions at the femur and tibia, and all the ligaments and synovial tissues between them were cut as stump resection group. LARS artificial ligament was then implanted into both two groups. At 20 months after implantation, the ligament healing was observed using CT and MRI examinations, the fibrous tissues were observed under scanning electron microscope, and the growth of newborn ligaments was observed by histological staining. RESULTS AND CONCLUSION: CT findings showed that in the stump group, the number of femoral tunnel enlargement was significantly more than that in the stump resection group (P < 0.05), while the number of tibial tunnel enlargement in the stump group was significantly less than that in the stump resection group (P < 0.05). LARS artificial ligament in the femoral and tibial tunnel and free part of the joint presented with hypointensity on T1- and T2-weighted images, which showed no significant difference between two groups. Under the scanning electron microscope there were obvious dense fibrous tissues between LARS artificial ligaments in both two groups; and the autologous fibrous tissues arranged closely and evenly under high magnification. Hematoxylin-eosin staining results showed that in the two groups, the LARS artificial ligaments in the free part of the articular cavity and bone tunnel were surrounded by a large number of autologous tissues in a fusiform arrangement; autologous fibrous tissues and artificial ligament were wrapped well but arranged irregularly; mature fibrous tissues and few capillary infiltration were found in the bone tunnel and free part of the joint cavity, but without necrotic tissues. Masson staining results showed that the inner and outer parts of the LARS in the bone tunnel were wrapped by blue collagen, the red-stained bones located outside the collagen, and no obvious transitional zone appeared. These results showed that the LARS artificial ligament holds good biocompatibility and fibrous tissue induction, which can promote bone healing.

BACKGROUND:Polyethylene terephthalate (PEA) holds good mechanical properties, but its biocompatibility needs to be improved. OBJECTIVE:To investigate the effect of bioactive glass modified PEA on bone healing. METHODS:In vitro experiment:PEA (control group) and bioactive glass modified PEA (experimental group) were respectively co-cultured with MC3T3-E1 cells. The cell morphology was observed at 3 days of culture, and the cell proliferation and alkaline phosphatase activity were detected at 1, 3 and 5 days of culture. In vivo experiment:24 New Zealand white rabbits were enrolled, modeled into unilateral knee ligament rupture, and then randomly allotted to two groups. Bioactive glass modified PEA and PEA were implanted into experimental and control groups, respectively. Biomechanics and histological changes were compared between groups at 6 and 12 weeks after transplantation. RESULTS AND CONCLUSION:In vitro experiment:the cell density in the experimental group was significantly higher than that in the control group after 3-day culture (P<0.05);the cell proliferation and alkaline phosphatase activity were significantly higher than those in the control group at 3 and 5 days of culture (P<0.05). In vivo experiment:the maximum axial pull-out strength in the experimental group was significantly greater than that in the control group at 6 and 12 weeks after implantation (P<0.05). In the control group, the defect was obvious and there were a large number of inflammatory cells at 6 weeks after implantation;the defect region became fuzzy, abundant inflammatory cells existed and new bone formed on the surface at 12 weeks after implantation. In the experimental group, there were newly formed bones and trabeculae formed on the interface, the scar tissue became less, and the interface width was narrow at 6 weeks after implantation;numerous new tissues were observed, and only a few inflammatory cells observed in the defect region at 12 weeks after implantation. These results indicate that the modified PEA with bioactive glass possesses good biocompatibility and biomechanics, which can promote bone healing.

Objective To investigate the safety and acute toxicities of intraoperative electron radiotherapy for patients with abdominal tumors.Methods From May 2008 to August 2009, 52 patients with abdominal tumors were treated with intraoperative electron radiotherapy,including 14 patients with breast cancer,19 with pancreatic cancer,3 with cervical cancer, 4 with ovarian cancer, 6 with sarcoma, and 6 with other tumors.Fifteen patients were with recurrent tumors.The intraoperative radiotherapy was performed using Mobetron mobile electron accelerator, with total dose of 9 - 18 Gy.In all, 29, 4 and 19 patients received complete resection, palliative resection and surgical exploration, respectively.The complications during the operations and within 6 months after operations were graded according to Common Terminology Criteria for Adverse Events v3.0 (CTC 3.0).Results The median duration of surgery was 190 minutes.Intraoperative complications were observed in 5 patients, including 3 with hemorrhage, 1 with hypotension,and 1 with hypoxemia, all of which were treated conservatively.The median hospitalization time and time to take out stitches was 12 and 13 days, respectively.And the in-hospital mortality was 4% (2/52).Twentyfour patients suffered post-operative adverse events, including 3 postoperative infections.With a median follow-up time of 183 days, 20% of patients sufferred from grade 3 to 5 adverse events, with hematological toxicities being the most common complication, followed by bellyache.Grade 1 and 2 toxicities which were definitely associated with intraoperative radiotherapy was 28% and 4%, respectively.None of grade 3 to 5 complications were proved to be caused by intraoperative radiotherapy.Conclusions Intraoperative electron radiotherapy is well tolerable and could be widely used for patients with abdominal tumors, with a little longer time to take out stitches but without more morbidities and toxicities compared surgery alone.

Objective:To evaluate the efficacy and safety of rubber band traction-assisted endoscopic submucosal dissection (ESD).Methods:A total of 49 patients with rectal endocrine tumor who underwent ESD at Beijing Friendship Hospital Affiliated to Capital Medical University from January 2016 to December 2019 were reviewed. Thirty-two patients who underwent traditional ESD from January 2016 to May 2018 were assigned to the non-traction group. Seventeen patients who underwent the operation with a rubber band as auxiliary traction from June 2018 to December 2019 were assigned to the traction group. Basic information, ESD procedure time, complications were compared between the two groups.Results:There were no significant differences in age, gender or lesion size between the traction group and the non-traction group ( P>0.05). The ESD operation time of the traction group was significantly shorter than that of the non-traction group (13.76±5.71 min VS 22.99±10.32 min, t=-3.408, P=0.001). There were no postoperative complications in the traction group, but 3 cases of perforation occurred in the non-traction group. There was no significant difference in the incidence of perforation between the two groups ( P=0.542). Conclusion:Rubber band traction can safely improve the efficiency of ESD.