A mechanical study on the bones of 29 rabbits following implantation of carbontendon was carried out. The rabbits were divided into seven groups according to the observation time (2,4,6,8,12,20 and 30 weeks after operation). A bundle of artificial tendon composed of 7,000 carbon fibers was passedthrough a tunnel in the tibia, and both ends of the artificial tendon were ligated to the muscle fibers. The mechanical strength and histological structure of the carbonbone junction and their relationship were studied in each group. Carbon fiberwas split and degradated in six to eight weeks after operation. The tensile strength of carbontendon in the soft tissue was decreased from 82±4.6N in the second week to 27±5.31N and6.3±1.81N in the sixth and eighth week respectively. The tensile strength of carbontendon increased from 3.01±1.2N to 6.1±2.01N at the carbon -tendon-bone junction in the bone. The tensile strength of carbon-tendon was unsatisfactory for implantation into bone. The carbon-tendon was split and degradated and the tensile strength was not b enough to cope with the early functional exercises.
OBJECTIVE: To investigate the clinical effects of revascularization in lower extremity for severe ischemia. METHODS: Fifty-six lower limbs with severe ischemia in 49 patients were evaluated retrospectively, who underwent surgical intervention from January of 1995 to December of 2000. By arteriography, the actual anatomic distributions of occlusive disease included infrarenal aorta-bicommon iliac arteries, abdominal aorta-bicommon iliac arteries, iliac artery, and femoral artery or femoropopliteal artery. The indication for surgery was disabling claudication, rest pain and gangrene. Fourteen limbs in 12 cases received arterialization of femoral venous system by artificial venous-arterial fistula. Artificial vascular grafts were implanted in 33 limbs of 28 cases, endarterectomy and patch profundaplasty were performed in 5 limbs of 5 cases, and primary amputation was carried out in 4 cases. RESULTS: During 38 months follow-up in average, 4 limbs were amputated within 52 revascularizated limbs, and accumulated amputation rate was 14.3%. Patency rate was 68.4% in arterial revascularization limbs (26/38 limbs), and limb survival rate was 94.7%(36/38 limbs) by procedure of artificial vascular grafts, endarterectomy and patch profundaplasty. Limb survival rate in procedure of artificial venous-arterial fistula was 85.7%(12/14 limbs). CONCLUSION: In treatment of severe lower extremity ischemia, the effective revascularization can be achieved by artificial vascular bypass, endarterectomy and patch profundaplasty, or arterialization of femoral venous system. Options in the surgical management should depend on individual. Arteriography is essential for revascularization and properly planning a practicable surgical approach.
Objective To investigate the clinical application of self-settingcalcium phosphate cement (CPC) in bone defect repair of extremities. Methods From May 1998 to January 2000, 32 cases of bone defect, in 36 sites, were repairedand reviewed, aged from 4 to 59 years old (24.7 years old on average), with bone defect 2 to 125 cm2 in size (13.1 cm2 on average). The causes of the bone defect werefracture, bone cyst, iliac bone harvesting, fibrous dysplasia, enchondroma and bone tuberculosis, which involved femur, iliac, tibia, humerus, phalanx, fibula, calcaneus, talus and acetabulum. All of the cases were followed up for 1 to 23 months, 15.3 months on average, before radiographic examination. Results All operations were successful and no general response was observed in all of the cases. X-ray examination showed an integrity interface between CPC and bone. And CT showed no gap existed. There was no increase of serum calcium and phosphate levels. Conclusion CPC is applicable in the low- or non-weight-bearing site of the extremities.
OBJECTIVE: To study the effect of platelet-rich plasma in the repair of bone defect. METHODS: Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides. RESULTS: Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side. CONCLUSION: Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.
ObjectiveTo explore the value of artificial intelligence (AI) diagnostic imaging system and three dimensional computed tomographic bronchoangiography (3D-CTBA) surgical planning system in the management of multiple primary lung cancer (MPLC).MethodsThe clinical data of 53 patients with MPLC treated surgically in our hospital from January 2018 to August 2020 were retrospectively analyzed, including 16 males and 37 females, with a median age of 60 (39-75) years. The patients' preoperative CT was analyzed by AI and manually, and the data of patients who underwent 3D-CTBA were compiled to evaluate the value of AI and 3D-CTBA in the diagnosis and treatment of MPLC, respectively.Results The sensitivity of AI screening for MPLC was 84.91%. The sensitivity (91.90% vs. 83.78%) and accuracy (85.60% vs. 84.00%) of AI diagnosis of high-risk MPLC infiltrative lesions were better than those of manual diagnosis. 3D-CTBA was used for planning the surgery in 12 patients, and the intraoperative situation was generally consistent with the reconstructed results.ConclusionAI is of high value in identifying infiltrative lesions of MPLC. 3D-CTBA reconstruction of anatomical structures is accurate and can guide preoperative planning.
OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.
In the past fifty more years, many research results have been achieved in the field of artificial esophagus which has been a major subject of surgical study on esophagus. Unfortunately,a very satisfactory artificial esophagus has not been found due to lack of proper artificial materials and problems of postoperative complications which results in great hindrance to applying them to clinical purpose. The current research focuses on artificial esophaguses constructed with acellular matrix as well as constructed through tissue engineering,furthermore,how to prevent and cure postoperative complications is still the main difficulty. This paper gives an overview of the recent study results,points in dispute, present status of research and the recent advances, and an overview to the future of artificial esophagus.
The primary results of five patients in whomthe block hydroxyapatite artificial bone (BHAB)used in maxillofacial plastic repair were reported. All incisions healed up with no evidence ofinfection. None of the implants was rejected norhad resorption changes. Satisfactory estheticaleffects were maintained. The results demonst-rated BHAB had a good biocampatibility andcould be used as a bone graft substitute inmaxillofacial plastic repair. This kind of material could be carved and contoured ...
Objective To investigate the operative methods, cl inical outcomes and compl ications of total hi p arthroplasty (THA) in the treatment of patient with hi p joint flexion rigidity due to ankylosing spondyl itis (AS). Methods From May 1992 to July 2004, 56 patients (32 left hips and 39 right hips) with AS received THA through a modified anterolateral approach, including 52 males (67 hips) and 4 females (4 hips) aged 17-48 years with an average of 35.5 years. All the hips were ankylosed in (43.1 ± 7.2)° of flexion and 15 patients had bilaterally ankylosed hips. Preoperatively, Harris hip score was (42.6 ± 5.3) points and all the hips were classified as stage IV according to the standard of American College of Rheumatology (ACR). And the course of disease was 3-11 years. Results Intraoperatively, 1 patient suffering from proximal femur fracture due to severe osteoporosis was treated with titanium wire fixation, and the fracture was healed 6 weeks later. All the patients were followed up for 3-15 years (average 5.3 years). Postoperatively, 1 patient (1 hip) got subcutaneous soft tissue infection at 8 days, 1 patient (1 hip) got wound disunion at 11 days, 2 patients (2 hips) got infection at 11 months and 3 years, respectively. All the infections were healed after symptomatic treatment. The wounds of the rest 52 patients were healed by first intention without joint infections. The postoperative X-rays demonstrated that 4 hips (5.6%) had loose acetabulum prosthesis, 3 hips (4.2%) had loose femoral prosthesis and 5 hips had loose acetabulum and femoral prosthesis (7.0%), and the total loosening rate was 16.8%. Among which, 8 hips received revision resulting in satisfactory therapeutic effects, and the rest 4 hips had no further treatment. Fifteen hips (21.1%) had heterotopic ossification, which was rel ieved after taking nonsteroidal anti-inflamatory drugs. Harris hip score at final follow-up was (82.7 ± 4.1) points, indicating there was a significant difference between before and after operation (P lt; 0.05). Ten hips were evaluated as excellent, 43 hips good, 14 hips fare, and 4 hips bad, and the excellent and good rate was 74.7%. Conclusion THA through the anterolateral approach is effective for the treatment of patient with hip joint flexion rigidity caused by AS.
OBJECTIVE To investigate the clinical application of artificial blood vessel graft for arteriovenous fistulization. METHODS From October 1995 to August 1998, 23 cases with renal failure received PTEF artificial vessels grafting for arteriovenous fistulization in the forearm. The PTFE artificial vessel was 6 mm in diameter, and 40 cm in length. Artificial vessel "U"-shaped loop was formed from elbow incision to wrist incision, and perfused by 20 ml heparin saline. The two ends of artificial vessel were end-to-side anastomosed with superficial cubital vein and cubital artery respectively. RESULTS All of arteriovenous fistulas were successfully formed, and could be performed hemodialysis periodically. The artificial vessels could be punctured repeatedly, and had sufficient volume of blood flow. It had no rejection, no formation of false aneurysm, and no ischemia in arm or exacerbated reflux to heart. CONCLUSION The artificial vessel grafting for arteriovenous fistulization is a safe and convenient technique in clinical practice, especially when there is no autogenous vessels for arteriovenous fistula.
