OBJECTIVE To investigate the methods to fabricate repair materials of tissue engineered peripheral nerve with bioactivity of Schwann cells (SC). METHODS 1. The materials were made by dry-wet spinning process to fabricate PLA hollow fiber canal with external diameter of 2.3 mm, internal diameter of 1.9 mm, thickness of 0.4 mm, pore size of 20 to 40 microns, pore ratio of 70% and non-spinning fiber net with pore size of 100 to 200 microns, pore ratio of 85%. 2. SC were implanted into excellular matrix (ECM) gel to observe the growth of SC. 3. SC/ECM complex were implanted into non-spinning PLA fiber net to observe the growth of SC. 4. SC, SC/ECM and SC/ECM/PLA were implanted into PLA hollow fiber canal to bridge 10 mm defect of rat sciatic nerve. RESULTS 1. SC were recovered bipolar shape at 1 day after implantation, and could be survived 14 days in ECM gel. 2. After SC/ECM complex was implanted into PLA net, most of SC were retained in the pore of PLA net with the formation of ECM gel. SC could be adhered and grown on PLA fiber. 3. Most of SC in ECM gel could be survived to 21 days after transplantation. Survival cell numbers of SC/ECM and SC/ECM/PLA groups were obviously higher than SC suspension group. CONCLUSION Non-spinning PLA porous biodegradable materials with ECM is benefit for SC to be adhered and grown.
ObjectiveTo evaluate the clinical outcome of valved homograft conduits (VHC) used for right ventricular outflow tract (RVOT) reconstruction in Fuwai Hospital in recent 13 years, and explore the factors influencing the long-term durability of VHC. MethodsClinical data of patients using VHC for RVOT reconstruction in Fuwai Hospital from November 2007 to October 2020 were retrospectively analyzed. The Kaplan-Meier survival curve was used to evaluate survival, VHC reintervention and VHC dysfunction. Cox proportional risk regression model was used to analyze the risk factors for VHC dysfunction. ResultsFinally 251 patients were enrolled, including 145 males and 106 females. The median age at surgery was 6.0 (0.3-67.0) years. Early death occurred in 5 (2.0%) patients. The follow-up was available for 239 (95.2%) patients, with the follow-up time of 0.3-160.0 (61.3±45.4) months. Five patients died during the follow-up, and the 1-year, 6-year, and 13-year survival rates were 96.6%, 95.5% and 95.5%, respectively. Eight patients received VHC reintervention during the follow-up, and freedom rates from VHC reintervention were 100.0%, 97.1% and 82.4% at 1 year, 6 years and 13 years, respectively. A total of 226 patients were followed up by echocardiography after discharge, with the follow-up time of 0.2-138.0 (48.5±40.5) months. During the follow-up, 46 (20.4%) patients developed VHC dysfunction, and freedom rates from VHC dysfunction at 1 year, 5 years, and 10 years were 92.6%, 79.6% and 59.3%, respectively. Univariate Cox regression analysis showed that age<6 years and VHC diameter<19 mm were risk factors for VHC dysfunction (P=0.029, 0.026), but multivariate regression analysis only indicated that age<6 years was an independent risk factor for VHC dysfunction (P=0.034). ConclusionThe early and late outcomes of VHC used for RVOT reconstruction are satisfactory, and the long-term durability of VHC is also optimal. In addition, age<6 years is an independent risk factor for VHC dysfunction.
ObjectiveTo summerize the early results of total cavopulmonary connection (TCPC) procedure with an extracardiac conduit in adults with congenital heart disease, and assess risk factors for postoperative delayed recovery in ICU. MethodsWe retrospectively analyzed the clinical data of 20 adult patients underwent TCPC operation with extracardiac conduit in Fu Wai Hospital between January 2012 and December 2014. There were 14 female and 6 male patients at age of 16 to 33 (20.45±4.33) years. ResultsThere was no hospital mortality. The time of ICU stay was 4.4±1.7 days. And time of hospital stay was 32.5±21.6 days. Morbidities included prolonged pleural effusion lasting more than 7 days in 12 patients (60.0%), new arrhythmias in 3 patients (15.0%), reexploration for bleeding in 3 patients (15.0%), surgical wound poor healing in 1 patient (5.0%). Dopamine and calcium were used in all the patients in the ICU, epinephrine in 18 patients, milrinone in 11 patients. Risk factors for postoperative delayed recovery in ICU were preoperative arrhythmias (P=0.02), cardiopulmonary bypass time longer than 120 min (P=0.04), plasma applications more than 2 000 ml (P=0.01), absence of fenestration (P=0.04), and pleural effusion lasting longer than 7 days (P=0.04). ConclusionThe TCPC procedure with an extracardiac conduit can be performed in adults with encouraged early results. Actively vasoactive drugs to maintain circulation early in ICU has good results for the patient's recovery.
Objective Comparing postoperative change of blood gas and hemodynamic status in patients underwent a right ventricletopulmonary artery (RVPA) conduit or a modified BlalockTaussig (mBT) shunt for pulmonary atresia with ventricular septal defect and without major arterial pulmonary collaterals (MAPCAs), to affirm the effect on oxygen supply /demand with different procedure. Methods From July 2006 to October 2007, 38 patients with pulmonary atresia and ventricular septal defect without MAPCAs were divided into two groups according to different procedures: RVPA group (n=25) and mBT group (n=13).Perioperative mortality, blood gas and hemodynamic data during postoperative 48 hours, including heart rate, blood pressure, systemic oxygen saturation, mixed venous oxygen saturation, oxygen excess factor, inotropic score were compared in both groups. Results The difference in the mortality between RVPA group (4.0％，1/25) and mBT group （7.7％，1/13) showed no statistical significance（Pgt;0.05）. The total of 33 patients were followed up, the followup time was from 6 to 18 months.11 patients (4 patients in mBT group, 7 patients in RVPA group) underwent corrected procedures during 9 to 18 months after palliative procedures, one case died of elevated pulmonary vascular resistance and right ventricle failure. The mixed venous oxygen saturation at 24h and 48h after surgery were higher than that at 6h after surgery (Plt;0.01) both in RVPA group and mBT group. The systolic blood pressures at 6h, 24h, 48h after surgery in RVPA group were lower than those in mBT group (P=0.048，0.043， 0.045)，the mean systemic blood pressures in RVPA group were higher than those in mBT group (P=0.048, 0.046, 0.049),the diastolic blood pressures in RVPA group were higher than those in mBT group (P=0.038, 0.034, 0.040)， the inotropic scores in RVPA group were lower than those in mBT group (P=0.035， 0.032，0.047). Conclusion The blood pressures and inotropic scores are found significantly different in RVPA conduit and mBT procedures, while postoperative systemic oxygen delivery areequivalent. Both RVPA and mBT patients decline to nadir in hemodynamic status at 6 h after surgery.
ObjectiveTo compare the long-term durability of valved homograft conduit (VHC) in patients with Ross and non-Ross right ventricular outflow tract (RVOT) reconstruction. MethodsPatients who underwent RVOT reconstruction using VHC in Fuwai Hospital from January 2008 to October 2020 were retrospectively included. Patients who received Ross RVOT reconstruction were allocated to a Ross group and patients who received non-Ross RVOT reconstruction were allocated to a non-Ross group. The survival and reintervention-free rates of the two groups were evaluated with the Kaplan-Meier survival curve and log-rank test. The propensity score matching analysis was performed on the patients who completed ultrasound follow-up in the two groups, and the VHC dysfunction-free rate was compared between the two groups. ResultsA total of 243 patients were enrolled, including 142 males and 101 females, with a median age of 6 years (4 months to 56 years). There were 77 patients in the ROSS group and 166 patients (168 operations) in the non-ROSS group. The cardiopulmonary bypass time in the Ross group was shorter than that in the non-Ross group (175.4±45.6 min vs. 200.1±83.5 min, P=0.003). Five patients in the non-Ross group died early after the operation. The follow-up was available in 231 patients (93.1%), with the average follow-up time of 61.7±44.4 months. During the follow-up, 5 patients in the non-Ross group died. The 12-year survival rate was 100.0% in the Ross group and 93.2% in the non-Ross group (log-rank, P=0.026). In addition, 1 patient in the Ross group and 7 patients in the non-Ross group received VHC reintervention. There was no significant difference in the reintervention-free rate between the two groups (log-rank, P=0.096). Among the 73 patients in the Ross group and 147 patients in non-Ross group who were followed up by ultrasound after discharge, 45 patients (20.5%) developed VHC dysfunction. Before matching, the long-term durability of VHC in the Ross group was better than that in non-Ross group (10-year VHC dysfunction-free rate: 66.6% vs. 37.1%, log-rank, P=0.025). After the propensity score matching, 64 patients included in each group, and there was no statistical difference in the long-term durability of VHC between the two groups (10-year VHC dysfunction-free rate: 76.3% vs. 43.0%, log-rank, P=0.065). In the subgroup analysis, the 10-year VHC dysfunction-free rate in the Ross group was higher than that in the non-Ross group (71.0% vs. 20.0%, log-rank, P=0.032) among patients aged<6 years at surgery. However, there was no significant difference in the 10-year VHC dysfunction-free rate between the two groups (53.7% vs. 56.7%, log-rank, P=0.218) among patients aged ≥6 years at surgery. ConclusionAfter the propensity score matching analysis, the long-term durability of VHC has no significant difference between the Ross group and non-Ross group. The long-term durability of VHC after Ross surgery is superior to that of non-Ross surgery in patients aged<6 years at surgery.
OBJECTIVE To explore the effect of basic fibroblast growth factor (bFGF) combined with autogenous vein graft conduit on peripheral nerve regeneration. METHODS Fifty four New Zealand rabbits were divided into three groups. The main trunk of sciatic nerve of rabbit in one side was severed and bridged by autogenous vein. 0.2 ml bFGF solution (4,000 U/ml) was intravenously injected to the vein graft conduit as group A, the same amount of saline solution as group B, and no solution injection as group C. Microscopic examination, axon video analysis and nerve conduct velocity were performed at the 10th, 30th, and 100th day after operation. RESULTS The nerve fibers were grown into vein graft conduit in all groups at 30th after operation, they were more and regular in group A than that of group B and C, and the axon regeneration rate in group A was more than that of group B and C. CONCLUSION bFGF combined with autogenous vein graft conduit can markedly promote nerve regeneration.
Objective To explore the advance in physical materials,chemical matrix, and biological seed cells for fabricating artificial nerve. Methods Recent literature relevant to artificial nerve, especially the achievement in physical material, chemical matrix and biological seed cells for fabricating artificial nerve, were extensively reviewed. Results Polymers of polylactic acid or polyglycolic acid and their polymer, polymer of hyaluronic acid and glut-aldehyde, polymer of polyacrylonitrile and polyvinylchloride were artificial nerve materials with the properties of good biocompatibility and biodegradation. A conduit with multichannel and high percentage of pores was beneficial to the regeneration of nerve. The activated Schwann cells were excellent seeds of artificial nerve. A suitable chemical matrix, such as laminin and alginate, could promote the regeneration of nerve. Conclusion The successful fabrication of artificial nerve lies in the advance in the mechanism of nerve regeneration and physical material, chemical matrix and biological seed cells.
Objective\ To search for suitable and multiple arterial grafts for myocardial revascularization, in order to avoid the long term problems of vein graft atherosclerosis. Methods\ Between October 1994 and April 2000, 456 consecutive patients underwent myocardial revascularization using radial artery and internal mammary artery. In coronary artery bypass grafting, minimally traumatic harvesting radial artery techniques and new pharmacologic antispasmodic agents was used. Results\ 448 internal mammary artery ...
Objective To assess the mid- and long-term outcomes of right ventricular outflow tract reconstruction for children with congenital heart disease. Methods We retrospectively analyzed the clinical data of 3 138 children with complex congenital heart disease in right heart system admitted to our hospital from January 2007 to January 2017. There were 1 660 males and 1 478 females. The age at surgery was 9 days to 84 months, and the body weight was 2.2 to 28.6 kg. Pulmonary patch enlargement was performed in 2 335 patients (1 477 patients of valve-sparing repair and 858 patients of transannular repair); autologous tissue (direct anastomosis, left auricle or pericardial conduit) was used to connect with right ventricle in 289 patients; extracardiac conduits were used for reconstruction in 514 patients. Results There were 181 in-hospital deaths with a mortality of 5.8%. The early postoperative causes of death were low cardiac output syndrome (LCOS), severe pulmonary hypertension and right heart failure. Fifteen patients died of cardiac insufficiency or sudden death during follow-up (6–27 months postoperatively). The echocardiography showed 408 patients with right ventricular outflow tract obsturction (RVOTO), 340 patients with pulmonary trunk or branches stenosis, 609 with pulmonary regurgitation (morderate or severe). 12.6% (394/3 138) of patients underwent reintervention or reoperation with 39 deaths. About 92.4% of patients exhibited an improvement of New York Heart Association (NYHA) functional class from Ⅲ or Ⅳ preoperatively to Ⅰ or Ⅱ at follow-up. Conclusion The anatomical structure of right ventricular outflow tract is complicated and various, and each operation method has different strengths and favorable outcomes. The operation should be individually designed according to pathological types, anatomical features, clinical symptoms and operation conditions.
ObjectiveTo investigate the in vivo degradation and histocompatibility of modified chitosan based on conductive composite nerve conduit, so as to provide a new scaffold material for the construction of tissue engineered nerve.MethodsThe nano polypyrrole (PPy) was synthesized by microemulsion polymerization, blended with chitosan, and then formed conduit by injecting the mixed solution into a customized conduit formation model. After freeze-drying and deacidification, the nano PPy/chitosan composite conduit (CP conduit) was prepared. Then the CP conduits with different acetyl degree were resulted undergoing varying acetylation for 30, 60, and 90 minutes (CAP1, CAP2, CAP3 conduits). Fourier infrared absorption spectrum and scanning electron microscopy (SEM) were used to identify the conduits. And the conductivity was measured by four-probe conductometer. The above conduits were implanted after the subcutaneous fascial tunnels were made symmetrically on both sides of the back of 30 female Sprague Dawley rats. At 2, 4, 6, 8, 10, and 12 weeks after operation, the morphology, the microstructure, and the degradation rate were observed and measured to assess the in vivo degradation of conduits. HE staining and anti-macrophage immunofluorescence staining were performed to observe the histocompatibility in vivo.ResultsThe characteristic peaks of the amide Ⅱ band around 1 562 cm−1 appeared after being acetylated, indicating that the acetylation modification of chitosan was successful. There was no significant difference in conductivity between conduits (P>0.05). SEM observation showed that the surfaces of the conduits in all groups were similar with relatively smooth surface and compact structure. After the conduits were implanted into the rats, with the extension of time, all conduits were collapsed, especially on the CAP3 conduit. All conduits had different degrees of mass loss, and the higher the degree of acetylation, the greater the mass change (P<0.05). SEM observation showed that there were more pores at 12 weeks after implantation, and the pores showed an increasing trend as the degree of acetylation increased. Histological observation showed that there were more macrophages and lymphocytes infiltration in each group at the early stage. With the extension of implantation time, lymphocytes decreased, fibroblasts increased, and collagen fibers proliferated significantly. ConclusionThe modified chitosan basedon conductive composite nerve conduit made of nano-PPy/chitosan composite with different acetylation degrees has good biocompatibility, conductivity, and biodegradability correlated with acetylation degree in vivo, which provide a new scaffold material for the construction of tissue engineered nerve.