Aiming at the problem of scaffold degradation in bone tissue engineering, we studied the feasibility that controlls bone defect repair effect with the inhomogeneous structure of scaffold. The prediction model of bone defect repair which contains governing equations for bone formation and scaffold degradation was constructed on the basis of analyzing the process and main influence factors of bone repair in bone tissue engineering. The process of bone defect repair and bone structure after repairing can be predicted by combining the model with finite element method (FEM). Bone defect repair effects with homogenous and inhomogeneous scaffold were simulated respectively by using the above method. The simulation results illustrated that repair effect could be impacted by scaffold structure obviously and it can also be controlled via the inhomogeneous structure of scaffold with some feasibility.
ObjectiveTo investigate the effects of micro-fracture and insul in-l ike growth factor 1 (IGF-1) in treatment of articular cartilage defect in rabbits. MethodsTwenty-four New Zealand white rabbits (aged, 4-6 months; weighing, 2.5-3.5 kg) were randomly divided into 4 groups (n=6):micro-fractures and recombinant human IGF-1 (rhIGF-1) treatment group (group A), micro-fracture control group (group B), rhIGF-1 treatment control group (group C), and blank control group (group D). Full thickness articular cartilage defects of 8 mm×6 mm in size were created in the bilateral femoral condyles of all rabbits. The micro-fracture surgery was performed in groups A and B. The 0.1 mL rhIGF-1 (0.01 μg/μL) was injected into the knee cavity in groups A and C at 3 times a week for 4 weeks after operation, while 0.1 mL sal ine was injected in groups B and D at the same time points. At 4, 12, and 24 weeks, the gross, histological, and immunohistochemical observations were performed, and histological score also was processed according to Wakitani's score criteria. The collagen contents in the repair tissues and normal patellofemoral cartilage were detected by the improved hydroxyproline (HPR) method at 24 weeks. Electron microscope was used to observe repair tissues of groups A and B at 24 weeks. Results All animals were survival at the end of experiment. At 24 weeks after operation, defect was repaired with time, and the repair tissue was similar to normal cartilage in group A; the repair tissue was even without boundary with normal cartilage in group B; and the repair tissue was uneven with clear boundary with normal cartilage in groups C and D. Histological staining showed that the repair tissues had no difference with normal cartilage in group A; many oval chondrocytes-l ike cells and l ight-colored matrix were seen in the repair tissues of group B; only a few small spindle-shaped fibroblasts were seen in groups C and D. Moreover, histological scores of group A were significantly better than those of groups B, C, and D (P<0.05) at 4, 12, and 24 weeks. Electron microscope observation showed that a large number of lacuna were seen on the surface of repair tissue in group A, and chondrocytes contained glycogen granules were located in lacunae, and were surrounded with the collagen fibers, which was better than that in group B. Collagen content of the repair tissue in group A was significantly higher than that in groups B, C, and D (P<0.05), but it was significantly lower than that of normal cartilage (P<0.05). Conclusion Combination of micro-fracture and rhIGF-1 for the treatment of full thickness articular cartilage defects could promote the repair of defects by hyaline cartilage.
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.
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.
ObjectiveTo investigate the feasibility of tissue engineered periosteum (TEP) constructed by porcine small intestinal submucosa (SIS) and bone marrow mesenchymal stem cells (BMSCs) of rabbit to repair the large irregular bone defects in allogenic rabbits. MethodsThe BMSCs were cultivated from the bone marrow of New Zealand white rabbits (aged, 2 weeks-1 month). SIS was fabricated by porcine proximal jejunum. The TEP constructed by SIS scaffold and BMSCs was prepared in vitro. Eighteen 6-month-old New Zealand white rabbits whose scapula was incompletely resected to establish one side large irregular bone defects (3 cm×3 cm) model. The bone defects were repaired with TEP (experimental group,n=9) and SIS (control group,n=9), respectively. At 8 weeks after operation, the rabbits were sacrificed, and the implants were harvested. The general condition of the rabbits was observed; X-ray radiography and score according to Lane-Sandhu criteria, and histological examination (HE staining and Masson staining) were performed. ResultsAfter operation, all animals had normal behavior and diet; the incision healed normally. The X-ray results showed new bone formation with normal bone density in the defect area of experimental group; but no bone formation was observed in control group. The X-ray score was 6.67±0.32 in experimental group and was 0.32±0.04 in control group, showing significant difference (t=19.871,P=0.001). The general observation of the specimens showed bone healing at both ends of the defect, and the defect was filled by new bone in experimental group; no new bone formed in the control group. The histological staining showed new bone tissue where there were a lot of new vessels and medullary cavity, and no macrophages or lymphocytes infiltration was observed in the defect area of experimental group; only some connective tissue was found in the control group. ConclusionTEP constructed by porcine SIS and BMSCs of rabbit can form new bone in allogenic rabbit and has the feasibility to repair the large irregular bone defects.
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 investigate the application of three-dimensional (3-D) printing technique combining with 3-D CT and computer aided-design technique in customized artificial bone fabrication, correcting mandibular asymmetry deformity after mandibular angle ostectomy. MethodsBetween April 2011 and June 2013, 23 female patients with mandibular asymmetry deformity after mandibular angle ostectomy were treated. The mean age was 27 years (range, 22-34 years). The disease duration of mandibular asymmetry deformity was 6-16 months (mean, 12 months). According to the CT data and individualized mandibular angle was simulated based on mirror theory, 3-D printed implants were fabricated as the standard reference for manufacturers to fabricated artificial bone graft, and then mandible repair operation was performed utilizing the customized artificial bone to improve mandibular asymmetry. ResultsThe operation time varied from 40 to 60 minutes (mean, 50 minutes). Primary healing of incisions was obtained in all patients; no infection, hematoma, and difficulty in opening mouth occurred. All 23 patients were followed up 3-10 months (mean, 6.7 months). After operation, all patients obtained satisfactory facial and mandibular symmetry. 3-D CT reconstructive examination results after 3 months of operation showed good integration of the artificial bone. Conclusion3-D printing technique combined with 3-D CT and computer aided design technique can be a viable alternative to the approach of maxillofacial defects repair after mandibular angle ostectomy, which provides a accurate and easy way.
ObjectiveTo explore the reliability and effectiveness of soft tissue defect reconstruction using the lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle.MethodsBetween December 2014 and December 2019, 13 patients underwent the reconstruction of soft tissue defects in various sites using the lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle. There were 10 males and 3 females, with an average age of 52.1 years (range, 29-83 years). Twelve wounds were resulted from resection of various malignant tumor, including 6 cases of head and neck tumors, 5 cases of shoulder and back tumors, 1 case of chest and back tumors. Among the 12 cases, 4 cases were complicated with wound infection and bone exposure, 1 case with skull defect and cerebral dura exposure, and 1 case with wound infection, skull necrosis, and cerebrospinal fluid leakage. One case was injured in a traffic accident, which resulted in infection wound in the back and shoulder and bone exposure. The sizes of the defect and musculocutaneous flap ranged from 11 cm×7 cm to 23 cm×15 cm and 25 cm×8 cm to 40 cm×14 cm, respectively. According to the spatial relationship between the donor and recipient sites, propeller flaps (8 cases) or percutaneous tunnel island flaps (5 cases) were used to transfer the myocutaneous flap to the recipient area to repair the wound. The donor site was directly closed and sutured in 9 cases, and those with excessive tension were repaired with free skin grafts in 2 cases or transferred flaps in 2 cases.ResultsAfter the operation, necrosis of the distal 4-cm of the musculocutaneous flap occurred in 2 cases. After debridement, the resultant wounds were reconstructed using a local flap and a posterior intercostal artery perforator flap, respectively. The remaining 11 myocutaneous flaps survived completely without arteries and veins crisis. The wounds in the donor and recipient areas healed by first intention. All the patients were followed up 1 to 48 months (mean, 7.4 months). The color and texture of the flap were good. During the follow-up, 1 patient underwent tumor resection again due to tumor recurrence, and 1 patient with a scalp hemangiosarcoma died due to unexplained thoracic hemorrhage. Tumor recurrence was not found in the remaining patients. The musculocutaneous flap coverage was stable and the infection was controlled.ConclusionThe lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle can be an alternation option to reconstruct refractory wounds with exposure of vital structures and organs and infection.
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.
【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.