Objective To explore the application effect of 3D printed heart models in the training of young cardiac surgeons, and evaluate their application value in surgical simulation and skill improvement. MethodsEight young cardiac surgeons were selected form West China Hospital as the trainees. Before training, the Hands-On Surgical Training-Congenital Heart Surgery (HOST-CHS) operation scores of the 8 cardiac surgeons were obtained after operating on 2 pig heart models of ventricular septal defect (VSD). Subsequently, simulation training was conducted on a 3D printed peri-membrane VSD heart model for 6 weeks, once a week. After the training, all trainees completed 2 pig heart VSD repair surgeries. The improvement of doctors’ skills was evaluated through survey questionnaires, HOST-CHS scores, and operation time after training. ResultsBefore the training, the average HOST-CHS score of the 8 trainees was 52.2±6.3 points, and the average time for VSD repair was 54.7±7.1 min. During the 6-week simulation training using 3D printed models, the total score of HOST-CHS for the 8 trainees gradually increased (P<0.001), and the time required to complete VSD repair was shortened (P<0.001). The trainees had the most significant improvement in scores of surgical cognition and protective awareness. The survey results showed that trainees were generally very satisfied with the effectiveness of 3D model simulation training. Conclusion The 3D printed VSD model demonstrates significant application advantages in the training of young cardiac surgeons. By providing highly realistic anatomical structures, 3D models can effectively enhance surgeons’ surgical skills. It is suggested to further promote the application of 3D printing technology in medical education, providing strong support for cultivating high-quality cardiac surgeons.
ObjectiveTo review the methods of improving the mechanical properties of hydrogels and the research progress in bone tissue engineering. MethodsThe recent domestic and foreign literature on hydrogels in bone tissue engineering was reviewed, and the methods of improving the mechanical properties of hydrogels and the effect of bone repair in vivo and in vitro were summarized. ResultsHydrogels are widely used in bone tissue engineering, but their mechanical properties are poor. Improving the mechanical properties of hydrogels can enhance bone repair. The methods of improving the mechanical properties of hydrogels include the construction of dual network structures, inorganic nanoparticle composites, introduction of conductive materials, and fiber network reinforcement. These methods can improve the mechanical properties of hydrogels to various degrees while also demonstrating a significant bone repair impact. ConclusionThe mechanical properties of hydrogels can be effectively improved by modifying the system, components, and fiber structure, and bone repair can be effectively promoted.
ObjectiveTo observe the short-term therapeutic outcomes of atrial septal defects (ASD) repair using on-pump beating-heart technique assisted by robotic surgery system (Da Vinci Si) or thoracoscopy.MethodsClinical data of 50 patients undergoing ASD repair at the First Affiliated Hospital of Anhui Medical University from January 2015 to December 2018 were retrospectively analyzed. According to the different surgical methods, patients were divided into a robot group and a total thoracoscopy group. In the robot group, there were 35 patients including 11 males and 24 females, at an average age of 42.1±16.8 years, and in the total thoracoscopy group there were 15 patients including 8 males and 7 females at an average age of 38.4±10.9 years. During follow-up, the left ventricular ejection fraction, left and right atrial diameter, and right ventricular end-diastolic diameter in the cardiac Doppler echocardiography were recorded. The operation time, extracorporeal circulation time, ventilation time, postoperative ICU stay, postoperative hospital stay, perioperative pleural drainage and early complications were compared between the two groups.ResultsIn the perioperative period, the robot group had less operation time (3.8±0.3 h vs. 6.1±1.4 h), extracorporeal circulation time (72.3 ± 10.4 min vs. 139.1 ± 32.8 min), ventilation time (5.5±1.2 h vs. 9.5 ± 2.1 h), postoperative hospital stay (6.7±0.5 d vs. 9.8 ± 0.6 d) and thoracic drainage (253.4±26.8 mL vs. 289.3 ± 29.5 mL) than the total thoracoscopy group (P<0.05), while the postoperative complications were not statistically significant between the two groups (P>0.05). All patients were reviewed by color Doppler ultrasound at 1 month after operation. The postoperative dilated right atrium, right ventricle and left atrium were smaller than those before surgery.ConclusionFor patients undergoing ASD repair, robot-assisted and total thoracoscopy can achieve good results, but the robot group has more advantages in terms of operation time, extracorporeal circulation time, ventilation time, postoperative hospital stay and thoracic drainage.
ObjectiveTo objectively evaluate the effectiveness of the ventricular fold pull-down combined with strip myofascial flap to repair laryngeal defect after early glottic carcinoma operation with glottic morphological parameters and voice parameters. MethodsBetween January 2008 and December 2012, 47 patients with early glottic carcinoma and anterior commissure involvement underwent partial laryngectomy. All patients were male, aged from 60 to 75 years (mean, 68.5 years). The disease duration was 4-11 months (mean, 7.2 months). According to American Joint Committee on Cancer (AJCC) TNM criteria, 28 cases were classified as T1aN0M0, 14 cases as T1bN0M0, and 5 cases as T2N0M0. Laryngeal defect after resection of tumor was repaired by ventricular fold pull-down combined with strip myofascial flap. At 1 day before operation and at 1 year after operation, multilayer spiral CT was used to scan larynx, to measure and compare the anteroposterior diameter of vocal area, the distance between both sides of the vocal process, and the thickness of soft tissue of vocal area, and the effect of combined soft tissue flap was objectively assessed in laryngeal morphology reconstruction. The actual voice parameters[including F0, Jitter, Shimmer, normalized noise energy (NNE), and maximum phonatory time (MPT)] were tested and compared, and the effect of the combined soft tissue flap on postoperative laryngeal pronunciation was evaluated. ResultsPostoperative pathological examination revealed well-differentiated squamous cell carcinoma in 38 cases, and moderately-differentiated squamous cell carcinoma in 9 cases; no tumor was found in the resection margin. Healing of neck incision was obtained in all patients at 7-9 days after operation. Forty-four cases were decannulated at 9-11 days after operation and the remaining 3 cases were decannulated at 3 weeks after operation. Oral feeding usually started in all cases at 3-4 days after operation. All patients were followed up 1 year. At 1 year after operation, the anteroposterior diameter of vocal area was significantly reduced when compared with preoperative one (t=15.161, P=0.000); the distance between both sides of the vocal process and the thickness of soft tissue of vocal area had no significant changes (P > 0.05). Compared with preoperative ones, there were significant differences in Shimmer, NNE, and MPT (P < 0.05), but no significant difference was found in F0 and Jitter (P > 0.05) at 1 year after operation. ConclusionVentricular fold pull-down combined with strip myofascial flap can repair laryngeal defect effectively after partial laryngectomy and maintain the effective airway after operation. It not only has no effect on postoperative laryngeal morphology, but also can be used as new laryngeal voice vibration body.
【Abstract】 Objective To investigate the effectiveness of the medical calcium sulfate—OsteoSet bone graft substitute in the treatment of defect after excision of jaw cyst. Methods Between December 2009 and May 2010, 15 cases of jaw cystic lesion were treated，including 9 males and 6 females with an average age of 36.6 years (range, 15-75 years). Orthopantomography (OPT) method was used to measure the cyst size before operation, and the size ranged from 1.5 cm × 1.5 cm to 8.0 cm × 3.0 cm. The range of bone defect was from 1.5 cm × 1.5 cm × 1.5 cm to 8.0 cm × 3.0 cm × 3.0 cm after cyst excision intraoperatively. The patients underwent cyst curettage and OsteoSet bone graft substitutes implantation (2-15 mL). Radiological method was used to evaluate the repair effect of OsteoSet pellets. Results The pathology biopsy was periapical cyst in 7 cases, odontogenic keratocyst in 5 cases, and dentigerous cyst in 3 cases. Fifteen patients were followed up 6-12 months. Thirteen patients achieved wound healing by first intention; 2 cases had longer drainage time (5 and 7 days, respectively), the incision healed after the pressure bandage. Swelling occurred in 1 case after 1 month with no symptom of infection. No postoperative infection and rejection was found. The X-ray examination showed that the materials filled the bone defect well after 1 day of operation. OsteoSet bone graft substitutes were absorbed by one-half after 1 month of operation and totally after 3 months by OPT. The low density area was smaller in the original cysts cavity, and high density in the cysts increased significantly with fuzzy boundaries of cysts. At 6 months after operation， there was no obvious difference in image density between the original cavity and normal bone, and the capsule cavity boundary disappeared, and defect area was full of new bone. Conclusion The medical calcium sulfate—OsteoSet bone graft substitute is an ideal filling material for bone defect.
Objective To explore the reliability and effectiveness of prediction of the pedicle length of the proximally-based anterolateral thigh (pALT) flap which was used to repair the defects following the resection of various malignant tumors using computed tomographic angiography (CTA). Methods The clinical data of 12 patients who met the selection criteria by using pALT flap to repair wounds left after malignant tumor resection between June 2015 and December 2020 were retrospectively analyzed. There were 5 males and 7 females; the age ranged from 16 to 80 years, with an average age of 54.4 years. After tumor resection, the soft tissue defect ranged from 15 cm×5 cm to 30 cm×12 cm; defect sites included 4 cases of lower abdomen, 3 cases of groin, 2 cases of thigh, and 3 cases of buttocks. Preoperative CTA was used to obtain the location information of the descending branch of the lateral femoral circumflex artery and its perforators by maximum density projection, and the length of the pedicle of pALT flap was estimated. Fasciocutaneous flap (5 cases) or myocutaneous flap (7 cases) were cut during operation to repair the defect, and the size of flap ranged from 20 cm×7 cm to 30 cm×12 cm. The donor site of thigh was directly sutured (11 cases) or repaired with skin graft (1 case). Bland-Altman analysis was used to detect the consistency between the pALT flap vascular pedicle length estimated by CTA and the pALT flap vascular pedicle length actually obtained during operation. ResultsOne case had distal blood supply disturbance of the flap and was repaired with skin graft after debridement; the remaining 11 flaps survived. All donor and recipient incisions healed by first intention. All 12 cases were followed up 1-12 months, with an average of 4.3 months. One patient died of pelvic tumor recurrence at 6 months after operation, and no tumor recurrence was found in the other patients. Preoperative CTA estimated that the length of pALT flap vascular pedicle was 9.3-24.7 cm, with an average of 14.7 cm; the actual length of pALT flap vascular pedicle was 9.5-25.0 cm, with an average of 14.8 cm. Bland-Altman analysis showed that there was no significant difference between the pALT flap vascular pedicle length estimated by CTA before operation and the pALT flap vascular pedicle length actually obtained during operation, and the average difference was 0.1 (95% consistency limit: –0.89, 0.74), indicating that they had good consistency. ConclusionCTA can be accurately used to localize the perforator and predict the possible pedicle length of the pALT flap. When performing a pALT flap surgery, preoperative CTA is helpful for surgeons to make a preliminary assessment of the difficult of the operation. The time for exploration of perforators and dissection of the vascular pedicle, and complications can be reduced, and the safety of the operation can be improved.
Objective To compare the effect between vascularization osteogenesis and membrane guided osteogenesis in the bone repair by the tissue engineered bone with pedicled fascial flap packing autologous red bone marrow (ARBM), so as to provide a reference for the bone defect repair in cl inic. Methods The tissue engineered bone was constructed with ARBM and the osteoinductive absorbing recombinant human materials with recombinant human bone morphogenetic protein 2. Sixty New Zealand rabbits (aged 4-5 months, weighing 2.0-2.5 kg) were randomly divided into group A (n=16), group B (n=22), and group C (n=22). The complete periosteum defect model of 1.5 cm in length was prepared in right ulnar bone, then the tissue engineered bone was implanted in the bone defect area in group A, the tissue engineered bonewith free fascial flap in group B, and the tissue engineered bone with pedicled fascial flap in group C. At 4, 8, 12, and 16 weeks, the tissue of bone defect area was harvested from 4 rabbits of each group for the general, histological, and immunohistochemical staining observations; at 8, 12, and 16 weeks, 2 rabbits of groups B and C, respectively were selected to perform ink perfusion experiment by axillary artery. Results The general observation showed that the periosteum-l ike tissues formed in the fascial flap of groups B and C, chondroid tissues formed in group B, new bone formed in group C, and the fibrous and connective tissues in group A at 4 and 8 weeks; a few porosis was seen in group A, more new bone in group B, and bone stump formation in group C at 12 and 16 weeks. Histological observation showed that there were few new blood vessels and new bone trabeculae in groups A and B, while there were large amounts of new blood vessels and mature bone trabeculae in group C at 4 and 8 weeks. There were a few new blood vessels and new bone trabeculae in group A; more blood vessels, significantly increased mature trabeculae, and the medullary cavity formation in group B; and gradually decreased blood vessels, the mature bone structure formation, and the re-opened medullary cavity in group C at 12 and 16 weeks. The immunohistochemical staining observation showed that the levels of CD105, CD34, and factor VIII were higher in group C than in groups A and B at different time points.The bone morphometry analysis showed that the trabecular volume increased gradually with time in 3 groups after operation; the trabecular volume in group C was significantly more than those in groups A and B at different time points (P lt; 0.05); and there was significant difference between groups A and B (P lt; 0.05) except the volume at 4 weeks (P gt; 0.05). The vascular image analysis showed that the vascular regenerative area ratio in group C was significantly higher than those in groups A and B at different time points (P lt; 0.05). The ink perfusion experiment showed that the osteogenic zone had sparse ink area with no obvious change in group B, while the osteogenic zone had more intensive ink area and reached the peak at 8 weeks, then decreased in group C. Conclusion The tissue engineered bone with pedicled fascial flap packing ARBM has the vascularization osteogenesis effect at early stage, but the effect disappears at late stage gradually when the membrane guided osteogenesis is main.
Objective To construct a new type of self-assembling peptide nanofiber scaffolds—RGDmx, and to study the cell compatibility of the new scaffolds and the proliferation and chondrogenic differentiation of precartilaginous stem cells(PSCs) in scaffolds. Methods PSCs were separated and purified from newborn Sprague Dawley rats by magnetic activated cell sorting and indentified by immunohistochemistry and immunofluorescent staining. The RGDmx were constructed by mixing KLD-12 and KLD-12-PRG at volume ratio of 1 ∶ 1. PSCs at passage 3 were seeded into the KLD-12 scaffold (control group) and RGDmx scaffold (experimental group). The proliferation of PSCs in 2 groups were observed with the method of cell counting kit (CCK) -8 after 1, 3, 7, and 14 days after culture. The RGDmx were constructed by mixing KLD-12-PRG and KLD-12 at different volume ratios of 0, 20%, 40%, 60%, 80%, and 100% and the prol iferation of PSCs was also observed. The complete chondrogenic medium (CCM) was used to induce chondrogenic differentiation of PSCs in different scaffolds. The differentiation of PSCs was observed by toluidine blue staining and RT-PCR assay. Results PSCs were separated and purified successfully, which were identified by immunohistochemistry and immunofluorescent staining methods. The results of CCK-8 showed that the absorbance (A) value in the experimental group increased gradually and reached the highest at 7 days; the A value in the experimental group was significantly higher than that in the control group at 7 days and 14 days (P lt; 0.05). Meanwhile, the A value in the RGDmx scaffold with a volume ratio of 40% was significantly higher than those in others (P lt; 0.05). After 14 days of induction culture with CCM, the toluidine blue staining results were positive in 2 groups; the results of RT-PCR showedthat the expression levels of collagen type II and the aggrecan in the experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion The self-assembling peptide nanofiber scaffold—RGDmx is an ideal scaffold for tissue engineer because it has good cell compatibility and more effective properties of promoting the differentiation of PSCs to chondrocytes.
Objective To investigate the effect of simvastatin on inducing endothel ial progenitor cells (EPCs) homing and promoting bone defect repair, and to explore the mechanism of local implanting simvastatin in promoting bone formation. Methods Simvastatin (50 mg) compounded with polylactic acid (PLA, 200 mg) or only PLA (200 mg) was dissolved in acetone (1 mL) to prepare implanted materials (Simvastatin-PLA material, PLA material). EPCs were harvested from bone marrow of 2 male rabbits and cultured with M199; after identified by immunohistochemistry, the cell suspension of EPCs at the 3rd generation (2 × 106 cells/mL) was prepared and transplanted into 12 female rabbits through auricular veins(2 mL). After 3 days, the models of cranial defect with 15 cm diameter were made in the 12 female rabbits. And the defects were repaired with Simvastatin-PLA materials (experimental group, n=6) and PLA materials (control group, n=6), respectively. The bone repair was observed after 8 weeks of operation by gross appearance, X-ray film, and histology; gelatin-ink perfusion and HE staining were used to show the new vessels formation in the defect. Fluorescence in situ hybridization (FISH) was performed to show the EPCs homing at the defect site. Results All experimental animals of 2 groups survived to the end of the experiment. After 8 weeks in experimental group, new bone formation was observed in the bone defect by gross and histology, and an irregular, hyperdense shadow by X-ray film; no similar changes were observed in control group. FISH showed that the male EPC containing Y chromosome was found in the wall of new vessels in the defect of experimental group, while no male EPC containing Y chromosome was found in control group. The percentage of new bone formation in defect area was 91.63% ± 4.07% in experimental group and 59.45% ± 5.43% in control group, showing significant difference (P lt; 0.05). Conclusion Simvastatin can promote bone defect repair, and its mechanism is probably associated with inducing EPCs homing and enhancing vasculogenesis.
Objective To discuss the role of heparan sulfate (HS) in bone formation and bone remodeling and summarize the research progress in the osteogenic mechanism of HS. Methods The domestic and abroad related literature about HS acting on osteoblast cell line in vitro, HS and HS composite scaffold materials acting on the ani-mal bone defect models, and the effect of HS proteoglycans on bone development were summarized and analyzed. Results Many growth factors involved in fracture healing especially heparin-binding growth factors, such as fibroblast growth factors, bone morphogenetic protein, and transforming growth factor β, are connected noncovalently with long HS chains. HS proteoglycans protect these proteins from protease degradation and are directly involved in the regulation of growth factors signaling and bone cell function. HS can promote the differentiation of stem cells into osteoblasts and enhance the differentiation of osteoblasts. In bone matrix, HS plays a significant role in promoting the formation, maintaining the stability, and accelerating the mineralization. Conclusion The osteogenesis of HS is pronounced. HS is likely to become the clinical treatment measures of fracture nonunion or delayed union, and is expected to provide more choices for bone tissue engineering with identification of its long-term safety.