Good collateral circulation can effectively improve the prognosis of patients with severe stenosis or occlusion of cerebral blood supply artery. Studies have shown that CT angiography (CTA) can non-invasively and intuitively evaluate the degree of stenosis and collateral blood flow in diseased vessels. Rapid and accurate CTA collateral circulation score is of great significance for clinical decision-making and judging the prognosis of ischemic stroke. At present, there are many scoring scales based on CTA collateral circulation. This article will review the existing 7 CTA collateral circulation scoring scales, the advantages and disadvantages of clinical application and related research progress in predicting prognosis, aiming to provide a reference for clinicians to choose the collateral circulation score scale and the best treatment plan according to different situations.
Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.
As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.
Objective To investigate appropriate treatment strategy and timing for patients with subacute myocardial infarction and severe ischemic mitral regurgitation （IMR）. Methods A total of 89 patients with subacute myocardial infarction and severe IMR underwent surgical treatment from January 2005 to December 2011 in Beijing Anzhen Hospital. There were 66 male patients and 23 female patients with their mean age of 64 （55-73） years. All the patients received only coronary artery bypass grafting （CABG） after 3 months of medication treatment without specific management for their IMR. Echocardiography was examined before medication treatment，preoperatively and 6 months after CABG to analyze their IMR degree and measure left ventricular end-systolic dimension （LVESD），left ventricular end diastolic dimension （LVEDD） and left ventricular ejection fraction （LVEF）. Results There was no surgery-related death，perioperative myocardial ischemia or other severe postoperative complication. Eighty-one patients （91.0%） were followed up for 6-60 months. At 6 months after CABG，mitral regurgitation area （3.1±1.3 cm2 vs. 5.6±2.3 cm2），LVEDD （51.3±4.2 mm vs. 54.3±5.5 mm） and LVESD （31.7±3.9 mm vs. 34.6±4.3 mm） were significantly decreased than preoperative values （P＜0.05），but LVEF was not statistically different from preoperative value （59.1%±3.9% vs. 58.9%±5.6%，P＞0.05）. From the third year during follow-up，all the patients received annual CT examination of their coronary artery，and no significant graft stenosis （graft stenosis＞50%） was found. Conclusion With appropriately delayed CABG and right medication treatment，patients with subacute myocardial infarction and severe IMR may no longer need concomitant surgical management for their IMR， which can decrease surgical risks and reduce treatment cost.
Objective To systematically evaluate the effectiveness of intra-articular hyaluronic acid injection after arthroscopic debridement for knee osteoarthritis (KOA). Methods Databases including The Cochrane Library, SCI, MEDLINE, EMbase, CBM and WanFang Data were searched from inception to 2012, so as to collect randomized controlled trials (RCTs) on intra-articular hyaluronic acid injection after arthroscopic debridement (combined therapy) vs. monotherapy in treating KOA. Two reviewers independently screened literature according to inclusion and exclusion criteria, evaluated quality, and extracted data. Then the meta-analysis was conducted using RevMan5.0 software. Results A total of 7 RCTs involving 526 patients were included. The results of meta-analyses showed that: there was no significant difference in the excellent-good rate between the combined therapy group and the monotherapy groups including either the intra-articular hyaluronic acid injection group (RR=1.40, 95%CI 0.99 to 1.98, P=0.06) or the arthroscopic debridement group (RR=1.09, 95%CI 0.93 to 1.26, P=0.29). But the intra-articular hyaluronic acid injection group was inferior to the combined therapy group in improving Lysholm score, with a significant difference (MD=–14.81, 95%CI –17.55 to –12.08, Plt;0.000 01). Conclusion Arthroscopic debridement combined with intra-articular hyaluronic acid injection for KOA shows no significant difference in the excellent-good rate compared with the monotherapy, but it is superior to the monotherapy of hyaluronic acid injection in improving Lysholm score, so it is believed the combined therapy group is superior to the control groups in therapeutic effects. Due to the limited quantity and quality of the included studies, this conclusion needs to be proved by performing more high quality RCTs
ObjectiveTo investigate the clinical characteristics of uniportal and three-port subxiphoid video-assisted thoracoscopic surgery (XVATS) extended thymectomy.MethodsThe clinical data of 60 consecutive patients of XVATS thymectomy in Xuzhou Central Hospital from January 2017 to May 2019 were retrospectively analyzed. There were 29 males and 31 females, with an average age of 53.1 (27.0-76.0) years. The patients were divided into an uniportal XVATS group (30 patients) and a three-port XVATS group (30 patients). The clinical effectiveness was compared between the two groups.ResultsThere was no significant difference in age, sex, body mass index, tumor size, intraoperative blood loss, postoperative time of thoracic tube indwelling and thoracic drainage, or postoperative hospitalization time between the two groups (P>0.05). There was no perioperative mortality, conversion to thoracotomy, thrombosis or mediastinal infection. The operation time of the uniportal XVATS group was significantly longer than that of the three-port group (87.5±19.0 min vs. 75.8±15.7 min, P=0.012). Besides, patients in the uniportal group had significantly lower pain score during 3-14 postoperative days than that of the three-port group (P=0.001).ConclusionUniportal XVATS extended thymectomy is feasible with less pain as compared with the patients using three-port XVATS, but it needs longer operation time at initial stage.
Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.
ObjectiveTo explore the feasibility and short-term efficacy of uniportal and three-port single-direction video-assisted thoracoscopic surgery (S-VATS) anatomical lobectomy for lung cancer.MethodsClinical data of 60 lung cancer patients, including 40 males and 20 females with an average age of 62.2±9.0 years, who received S-VATS anatomic lobectomy and systematic lymph nodes dissection by the same surgeon in our hospital between July 2016 and January 2019 were retrospectively analyzed. These patients were divided into a uniportal S-VATS group and a three-port S-VATS group according to surgical procedures, with 30 patients in each group. The clinical data of the two groups were compared.ResultsThere was no conversion to thoracotomy, surgical port addition, or mortality in this cohort, with tumor-negative surgical margin. There was no statistical difference in the operation time between the two groups (70.8±16.4 min vs. 73.7±14.3 min, P>0.05). Meanwhile, both groups showed similar intraoperative blood loss, stations and numbers of dissected lymph nodes, incidence of operation-related complications, duration and volume of chest tube drainage, as well as postoperative hospital stay (P>0.05). Besides, pain score of the patients in the uniportal S-VATS group was significantly lower than that of the three-port S-VATS group on postoperative 3-14 d (P<0.05). The mean duration of follow-up was 10 months, and all the patients were survived without tumor recurrence or metastasis.ConclusionThe transition from three-port S-VATS to uniportal S-VATS anatomical lobectomy for treatment of lung cancer is feasible. However, further studies are needed to elucidate the optimal resection sequence of pulmonary vessels.
Objective To evaluate postoperative quality of life （QOL） of patients aged over 65 after mitral valvereplacement （MVR）. Methods Ninety patients aged over 65 undergoing MVR by the same surgical group in Departmentof Cardiovascular Surgery of Anzhen Hospital were prospectively enrolled in this study. There were 62 male and 28 femalepatients with their age of 65-76 （68.6±6.8） years. There were 55 patients with hypertension，38 patients with type 2 diabetes，and all the patients had persistent atrial fibrillation. Nottingham Healthy Profile （NHP，Part I） and Duke Activity StatuIndex （DASI） were used to evaluate preoperative and postoperative QOL. According to the choice of prosthetic heart valves they received，all the patients were divided into two groups with 45 patients in each group: biological valve group and mechanical valve group. All the patients received MVR via the interatrial groove approach under general anesthesia and cardiopulmonary bypass. Mechanical valve replacement was performed using continuous suture without preserving the posterior leaflet of the mitral valve. Biological valve replacement was performed using interrupted suture and some of the posteriorleaflet of the mitral valve was routinely preserved. Patients in both groups underwent intraoperative bilateral pulmonary vein isolation and left atrial appendage ablation using a bipolar radiofrequency ablation device. The left atrial appendage was not excised or ligated. Results Postoperative QOL of all the patients was significantly better than preoperative QOL. There was no statistical difference in NHP and DASI at the 6th month after discharge between the 2 groups. But from the 1st year after discharge，QOL of the biological valve group was significantly better than that of the mechanical valve group. At the 3rd year after discharge，NHP and DASI of the mechanical valve group was not statistically different from those at the 1st year after discharge，but NHP and DASI of the biological valve group was significantly better than those at the 1st year after discharge. Conclusions QOL of elderly patients are significantly improved after MVR. Patients who receive biologicalvalve replacement may acquire better long-term QOL than patients who receive mechanical valve replacement.
Objective To investigate the method and the effectiveness of arthroscopy and/or arthrotomy combinedwith postoperative radiotherapy for diffuse pigmented villonodular synovitis (PVNS) of the knee. Methods BetweenSeptember 2000 and August 2010, 97 patients with diffuse PVNS of the knee were treated. There were 38 males and 59 femaleswith a median age of 33 years (range, 8-75 years). The disease duration ranged from 1 week to 30 years, including 52 left kneesand 45 right knees. There were 10 recurrent cases. The extention and flexion of the knee joint were (1.9 ± 2.3)° and (122.9 ± 5.6)°,respectively; the Lysholm score was 43.2 ± 6.7; and the International Knee Documentation Committee (IKDC) score was53.2 ± 5.7, preoperatively. According to the scope and degree of the knee joint lesions, simultaneous anterior and posteriorsynovectomy was performed under arthroscopy in 82 cases, synovectomy under arthroscopy and removal of posterior extraarticularlesion by arthrotomy in 3 cases, synovectomy and the soft tissue lesions resection under arthroscopy in 9 cases, andstaging resection and bone graft in 3 cases. After operation, 76 patients received postoperative radiotherapy. Results Poplitealartery was injuryed in 1 case and the branch of popl iteal veins were injuryed in 3 cases during operation. Intra-articularhemorrhage occurred in 1 case at 3 days after operation. The other patients achieved heal ing of incision by first intentionwithout nerve damage and other complications. All patients were followed up 1 year and 3 months to 11 years and 2 months(median, 61 months) postoperatively. During follow-up, 89 cases had no relapse. At 15 months after operation, the extentionand flexion of the knee joint were (0.2 ± 1.3)° and (135.9 ± 6.6)°, respectively; the Lysholm score was 89.8 ± 5.8; and the IKDCscore was 87.8 ± 5.8. All indexes were significantly improved when compared with the preoperative ones (P lt; 0.05). At 6 monthsto 8 years postoperatively, 8 cases had occurrence, and they had sl ight limitation of the range of motion but had no pain andswelling of the knees after reoperation. Conclusion According to the scope and degree of the knee joint lesions, arthroscopyand/or arthrotomy combined with postoperative radiotherapy should be chosen for diffuse PVNS of the knee so as to obtain good effectiveness. Radiotherapy and enough total radiation dose are important factors to insure no recurrence.