This study aims to explore the effect of aortic sinus diameter on aortic valve opening and closing performance in the case of no obvious disease of aortic valve and annulus and continuous dilation of aortic root. A total of 25 three-dimensional aortic root models with different aortic sinus and root diameters were constructed according to the size of clinical surgical guidance. The valve sinus diameter DS is set to 32, 36, 40, 44 and 48 mm, respectively, and the aortic root diameter DA is set to 26, 27, 28, 29 and 30 mm, respectively. Through the structural mechanics calculation with the finite element software, the maximum stress, valve orifice area, contact force and other parameters of the model are analyzed to evaluate the valve opening and closing performance under the dilated state. The study found that aortic valve stenosis occurs when the DS = 32 mm, DA = 26, 27 mm and DS = 36 mm, DA = 26 mm. Aortic regurgitation occurs when the DS = 32, 36 and 40 mm, DA = 30 mm and DS = 44, 48 mm, DA = 29, 30 mm. The other 15 models had normal valve movement. The results showed that the size of the aortic sinus affected the opening and closing performance of the aortic valve. The smaller sinus diameter adapted with the larger root diameter and the larger sinus diameter adapted with the smaller root diameter. When the sinus diameter is 40 mm, the mechanical performance of the valve are good and it can well adapt with the relatively large range of aortic root dilation.
ObjectiveTo investigate the feasibility and effectiveness of using ultrasound to evaluate the internal mammary artery (IMA) and explore the related factors affecting the quality of IMA.MethodsFrom July 2020 to January 2021, for patients who underwent coronary artery bypass grafting at the Department of Cardiovascular Surgery, Fuwai Hospital, ultrasound was applied to measure bilateral IMA at the parasternal second intercostal space. There were 62 males and 18 females with an average age of 59.9±8.3 years. The clinical data of the patients were recorded and analyzed.ResultsA total of 160 IMA were measured. The IMA was detected in 99.4% (159/160), and the one that was not measured was proved to be occluded by enhanced CT. A total of 157 (98.1%) IMA intima were smooth, 2 (1.3%) were found to have uneven intimal thickening and less smooth, and only 1 (0.6%) was occluded. The intravascular diameter, peak systolic flow rate, peak diastolic flow rate, and blood flow rate of the left second intercostal IMA were 1.9±0.3 mm, 66.8±17.7 cm/s, 6.4 (0.0, 9.7) cm/s, 19.7±9.4 mL/min; and those of the right one were 2.1±0.3 mm, 69.7±18.5 cm/s, 6.0 (0.0, 9.2) cm/s and 22.8±11.5 mL/min, respectively. IMA vessel diameter and blood flow were greater on the right than those on the left side in the same individual (P<0.01). In univariate analysis, sex and body surface area were the factors that influenced the size of the IMA vessel among different individuals, and by linear regression analysis, the size of the IMA vessel was only related to body surface area among different individuals. On univariate analysis, diabetes mellitus was the only factor affecting IMA blood flow, with a mean reduction in blood flow of 18.4% (left) and 21.7% (right) in the diabetic group (P<0.05).ConclusionPreoperative evaluation of the IMA using ultrasound over the parasternal second intercostal space is easy, noninvasive, and has a high success rate. The internal diameter of the IMA is positively correlated with body surface area, and blood flow is significantly reduced in patients with diabetes.
Objective To explore the strategy of intrathoracic anastomosis in patients with esophageal squamous cell carcinoma when the proximal esophagus is dilated to different degrees and explore its mechanism. Methods We retrospectively reviewed the clinical data of patients who underwent esophagectomy between 2014 and 2017 in West China Hospital. The patients were divided into two groups including a significant dilatation group with inner mucosal phase diameter (IMPD)≥17.9 mm and a non-significant dilatation group with IMPD<17.9 mm. And the patients were divided into two groups (a layered manual anastomosis group and a stapled anastomosis group) according to anastomosis method and propensity score matching was applied to adjust for potential confounders. Results We finally included 654 patients. There were 206 patients with 158 males and 48 females at average age of 62.21±7.72 years in the layerd manual analstomosis group and 448 patietns with 377 males and 71 females at average age of 62.57±8.42 years in the stapled anastomosis group. We also used Masson trichrome staining to assess the collagen fiber content in the esophagus. Compared with layered manual anastomosis, the incidence of anastomotic leakage was higher in the significant dilatation group than that in the stapled anastomosis group (original cohort: 3.8% vs. 10.7%, P=0.093; propensity score-matched cohort: 1.4% vs. 15.3%, P=0.004). And there was no significant difference in anastomotic leakage b etween layered manual anastomosis and stapled anastomosis in the non-significant dilatation group (original cohort: 4.7% vs. 4.2%, P=0.830; propensity score-matched cohort: 4.8% vs. 4.0%, P=0.206). Moreover, the average collagen fiber area ratio was significantly lower in the significant dilation group than that in the non-significant dilatation group (P=0.045). Conclusion There is a significant reduction in collagen fibers in the proximal esophageal wall tissue of esophageal squamous cell carcinoma patients with a IMPD≥17.9 mm. Intrathoracic layered manual anastomosis effectively reduces postoperative anastomotic leakage in these patients.
Objective To evaluate the effectiveness of multiple small-diameter drilling decompression combined with hip arthroscopy for early oeteonecrosis of the femoral head (ONFH). Methods Between March 2010 and December 2013, 91 patients with early ONFH were treated with the operation of multiple small-diameter drilling decompression combined with hip arthroscopy in 39 cases (53 hips, group A) or with drilling decompression alone in 52 cases (74 hips, group B). The patients in 2 groups had obvious hip pain and limited motion before operation. There was no significant difference in gender, age, etiology, effected side, stage of osteonecrosis, and preoperative Harris score between 2 groups (P>0.05). Results All operations succeeded and all incisions healed by first intention. The operation time was significantly longer in group A [(73.3±10.6) minutes] than in group B [(41.5±7.2) minutes] (t=8.726, P=0.000). Temporary of sciatic nerve apraxia after operation occurred in 2 patients of group A, and no complication occurred in other patients. Patients were followed up 24-52 months (mean, 39.3 months) in group A and 24-48 months (mean, 34.6 months) in group B. At last follow-up, the Harris scores were 83.34±8.76 in group A and 76.61±9.22 in group B, showing significant differences when compared between 2 groups (t=–4.247, P=0.029) and when compared with preoperative values in 2 groups (t=–10.327, P=0.001; t=–8.216, P=0.008). X-ray films showed that the collapse of the femoral head was observed in 6 hips (1 hip at stage Ⅰand 5 hips at stage Ⅱ) in group A, and in 16 hips (4 hips at stageⅠand 12 hips at stage Ⅱ) in group B; and hip arthroplasty was performed. The total effective rates were 88.68% (47/53) in group A and 78.38% (58/74) in group B, respectively; showing significant difference between 2 groups (χ2=5.241, P=0.041). Conclusion Multiple small-diameter drilling decompression combined with hip arthroscopy is effective in pain relief, improvement of hip function, slowing-down the process of femoral head necrosis, delaying the need for total hip arthroplasty in patients with early ONFH.
Objective To analyze the quantitative relationship between respiratory effort and inferior vena cava (IVC) diameter variability in healthy adults, and explore the effects of respiratory effort on the fluid responsiveness with IVC diameter variability. Methods From October 2022 to May 2023, a cross-sectional study was conducted in healthy young subjects who met the criteria. Respiratory effort was evaluated by using portable pulmonary function to measure the subjects’ inspiratory conditions in three states (quiet breathing, moderate inspiration, and maximal inspiration). At the same time, the IVC internal diameter was measured by bedside ultrasound and the IVC diameter variability was calculated. The correlation between inspiratory volume and IVC diameter variation was analyzed, and the receiver operator characteristic (ROC) curve was drawn. The sensitivity and specificity of fluid responsiveness induced by inspiratory effort were predicted according to the area under the ROC curve (AUC). Results A total of 95 subjects were screened, aged 27.13±5.77 years, of whom 30 (32%) subjects were males. During quiet breathing, 41.1% of subjects had IVC inner diameter variation ≥50%. For moderate inspiration, it was 68.4%. At maximum inspiration, this proportion is more than 85%. Inspiratory volume was moderately positively correlated with IVC diameter variation, and the correlation coefficient r=0.45. With the IVC diameter variation ≥50% as the positive criterion for fluid responsiveness, the AUC of fluid responsiveness induced by inspiratory effort was 0.73 (95% confidence interval 0.67 - 0.78, P<0.001), and the inspiratory volume threshold was 13 mL/kg ideal body weight when the maximum Youden index was 0.41. That is, moderate force breathing can induce fluid responsiveness, with sensitivity of 79.57% and specificity of 61.62%. Conclusion The degree of respiratory effort significantly affects the IVC inner diameter variation, and there may be false positives in the evaluation of fluid responsiveness according to IVC inner diameter variation in the case of spontaneous breathing.
The aim of the present experimental study is to determine the effects of sinotubular junction diameter on artificial bioprosthesis valves. An experimental study was performed for aortic root models with different sinotubular junction taper under pulsatile flow condition. The sinotubular junction diameters were modified to create four models with different sinotubular junction tapers with 0, 1, 3 and 5 degrees, respectively, using three dimensional printing techniques. After installing the testing bioprosthesis valve on the aortic root models, we conducted experiments of the pulsatile flow testing with different stroke volume in the pulsatile circulation simulation system. The testing condition was set at the pulse frequency of 70 beats/min and the stroke volume of 2–7 L/min. The status of the valves in 10 continuous pulse cycles was tested and the average results were obtained for each stroke volume. The results of testing showed that the mean transvalvular pressure gradients agreed well with the national standard, and all smaller than 10 mm Hg. The sinotubular junction taper had an influence on regurgitation fraction of the artificial bioprosthesis valve. The smaller sinotubular junction taper showed beneficial effect to decrease the regurgitation fraction. In the case of smaller stroke volume, the smaller sinotubular junction taper was beneficial to increase the effective valve orifice area. In the case of larger stroke volume, the larger sinotubular junction taper was beneficial to increase the effective valve orifice area. This study indicates that a doctor should consider the smaller sinotubular junction taper in the case of smaller stroke volume more. In the case of larger stroke volume, the doctor should consider the larger sinotubular junction taper more.
Objective To prepare a spider silk protein bilayer small diameter vascular scaffold using electrospinning, and to observe the blood compatibility in vitro. Methods The Arg-Gly-Asp-recombinant spider silk protein (pNSR16), polycaprolactone (PCL), gelatin (Gt), and heparin (Hep) were blended. Spider silk protein bilayer small diameter vascular scaffold (experimental group) was prepared by electrospinning, with pNSR16 ∶ PCL ∶ Hep (5 ∶ 85 ∶ 10, W/W) hybrid electrospun solution as inner spinning solution and pNSR16 ∶ PCL ∶ Gt (5 ∶ 85 ∶ 10, W/W) hybrid electrospun solution as outer spinning solution, but pNSR16 ∶ PCL (5 ∶ 85, W/W) hybrid electrospun solution was used as inner spinning solution in control group. The scaffold structure of experimental group was observed under scanning electron microscope (SEM); and the hemolysis rate, recalcification clotting time, dynamic clotting time, platelet adhesion, and platelet activation in vitro were compared between 2 groups. Results SEM results showed that bilayer fibers of scaffold were quite different in experimental group; the diameter distribution of inner layer fibers was relatively uniform with small pores, however diameter difference of the outer layer fiber was relatively big with big pores. The contact angle, hemolysis rate, recalcification clotting time, and P-selectin expression of scaffold were (35 ± 3) ° , 1.2% ± 0.1%, (340 ± 11) s, and 0.412 ± 0.027 respectively in experimental group, and were (70 ± 4) ° , 1.9% ± 0.1%, (260 ± 16) s, and 0.678 ± 0.031 respectively in control group; significant difference were found in indexes between 2 groups (P lt; 0.05). With the extension of time, the curve of coagulation time in experimental group sloped downward slowly and had a long time; the blood clotting index values before 30 minutes were significantly higher than those in control group (P lt; 0.05). Platelet adhesion test showed that the scaffold surface almost had no platelet adhesion in experimental group. Conclusion The spider silk protein bilayer small diameter vascular scaffold could be prepared through electrospinning, and it has good blood compatibility in vitro.
ObjectiveTo detect the difference in the osteogenesis ability of biphasic calcium phosphate (BCP) ceramic granular materials with different mesoporous diameters prepared at different sintering temperatures through in vivo and in vitro experiments, so as to provide evidence for screening BCP materials with better clinical application parameters.MethodsThree kinds of BCP (materials 1, 2, 3) were prepared by mixing hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) at a ratio of 8∶2 and sintered at 1 050, 1 150, and 1 250℃ for 3 hours, respectively. The internal porosity and the diameter, volume, and area of the mesopore were measured by Brunauer-Emmett-Teller test (BET); the composition of the material was evaluated by X-ray diffraction (XRD); the microscopic surface morphology of the material was observed by scanning electron microscopy (SEM). The 3rd generation bone marrow mesenchymal stem cells (BMSCs) from Sprague-Dawley rats were co-cultured with the materials 1, 2, and 3 for 7 days in vitro respectively (groups A, B, and C), and the cells adhesion on the materials was observed by SEM and phalloidine staining, respectively. Cell proliferation activity was measured by cell counting kit 8 method. In vivo, 9 muscle bags were made in dorsal muscles of 9 beagles, respectively. The muscle bags were randomly divided into 3 groups (3 per beagle in each group) and materials 1, 2, and 3 were placed into the muscle bags of groups A, B, and C, respectively. After 1, 2, and 3 months of operation, 3 beagles were anesthetized and the samples were stained with HE, Masson, and Safranin, and the bone formation area ratio in the BCP gap was calculated. Real-time fluorescence quantitative PCR (qRT-PCR) was performed to detect the expressions of bone-related genes [including alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OC)].ResultsThe BET test showed that with the increase of sintering temperature, the internal porosity of the particles did not change significantly, but the diameter, volume, and area of the mesopores gradually decreased. The XRD detection showed that the XRD waves of HA and β-TCP could be seen in all 3 kinds of materials; SEM showed that there were widely distributed macropores on the surface of 3 kinds of BCPs, and the interpores connected with the others. In vitro, BMSCs adhered and proliferated on the surfaces of 3 kinds of BCPs, and the cell biocompatibility of the materials in groups B and C was better than that in group A. In vivo, obvious osteoid tissue deposition could be observed in the intergranular space of 3 kinds of BCPs from 2 months after implantation. The bone formation area ratio of each group increased with time. The bone formation area ratio in group A was significantly higher than that in groups B and C at 2 and 3 months after implantation, and in group A than in group B at 1 month (P<0.05). qRT-PCR showed that the expressions of osteogenic related genes peaked at 2 months in group A, and gradually increased with time in groups B and C. The relative expressions of ALP and OPN mRNAs in group A were significantly higher than those in groups B and C at 1 month after implantation, the relative expression of OC mRNA in group A was significantly higher than that in groups B and C at 2 months after operation, the relative expression of ALP mRNA in groups B and C and the relative expression of OPN mRNA in group B were significantly higher than those in group A, all showing significant differences (P<0.05); there was no significant difference in the relative expression of each gene among the other groups at each time point (P>0.05).ConclusionThe mesoporous diameter of BCP decreases with the increase of sintering temperature. Different mesoporous diameters lead to different ectopic osteogenesis of BCP materials. BCP material with mesoporous diameter of 12.57 nm has better osteogenic ability which can activate the osteogenic gene earlier. The mesoporous diameter is expected to be an adjustable index for optimizing the osteogenic capacity of BCP materials.
ObjectiveTo evaluate the diagnostic efficacy of thyroglobulin in fine-needle aspirate fluid (FNA-Tg) for detecting cervical lateral lymph node metastases (LLNM) in differentiated thyroid cancer (DTC). MethodsThe clinical data of DTC patients who underwent (selective) cervical lateral lymph node dissection at the 900th Hospital of the Joint Logistics Support Force from February 1, 2021 to November 30, 2023 were retrospectively analyzed. The significance level (α) was set as 0.05. ResultsAccording to the inclusion and exclusion criteria, a total of 155 patients with 179 lymph nodes were included, among which 49 lymph nodes were not metastatic and 130 were metastatic. The results of the integral patients showed that the area under the receiver operating characteristic curve (AUC) of FNA-Tg for distinguishing cervical LLNM in the patients with DTC was superior to that of fine-needle aspiration cytology (FNAC). The AUCs (95% confidence intervals) were 0.973 (0.950, 0.995) and 0.778 (0.708, 0.849) respectively, P<0.05, and the AUC (95% confidence interval) of the combination of the two was higher [0.978 (0.959, 0.997)]. The optimal diagnostic threshold of FNA-Tg was determined to be 16.45 μg/L or FNA-Tg/serum thyroglobulin (sTg) was 1.02. After stratification based on the size of the lymph nodes, a paired analysis of the two methods (FNA-Tg and FNAC) showed that the diagnostic efficiency of FNA-Tg was significantly higher than that of FNAC only when the short diameter of the lymph node was ≤0.8 cm [0.955 (0.919, 0.992) vs. 0.718 (0.630, 0.806), P<0.001], and there was no additional benefit from the combination of the two [0.950 (0.912, 0.989)]. ConclusionsThe results of this study suggest that FNA-Tg shows a good diagnostic efficacy for cervical LLNM in patients with DTC, especially has an obvious advantage for small lymph nodes with a short-axis diameter of lymph node ≤0.8 cm. Its optimal diagnostic threshold is 16.45 μg/L or FNA-Tg/sTG is 1.02.
To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobil ized lumina in animal test. Methods Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by di pping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobil ized with rF II. Twenty hybrid male dogs [weighing (20 ± 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobil ized PU group, no rF II -immobil ized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days,the patency rate of every group was calculated. At 60 days IDs were measured, cell prol iferation in neointima was inspected by l ight microscope, morphology on neointima was observed by SEM. Results The ID of the PU vascular grafts was (3.74 ± 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racical compl iance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 ± 41) μm in the outside layer, pore size was (100 ± 3) μm in the inside layer, thickness ratio of outside / inside layers was 2 ∶ 1, the pore size was (40 ± 16) μm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no compl ication. At 30 days and 60 days after implantation, the patency rate for rF II -immobil ized PU group were 100% and 66.7%, for no rF II -immobil ized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastamotic sites of some grafts occluded. Before operation the IDs for rF II-immobil ized PU group, no rF II -immobil ized PU group and ePTFE group were (3.74 ± 0.06), (3.74 ± 0.06) and (4.00 ± 0.03) mm, at 60 days after operation the IDs were (4.51 ± 0.05), (4.31 ± 0.24) and (4.43 ± 0.12) mm respectively, showing no statistically significant differences between 3 groups (P gt; 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end ofgraft were (560 ± 22), (78 ± 5) and (323 ± 31) μm respectively for rF II -immobil ized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. Conclusion Immobil ization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embol ia which led to an increase in patency rate after implantation.