In maxillofacial surgery, there is a significant need for the design and fabrication of porous scaffolds with customizable bionic structures and mechanical properties suitable for bone tissue engineering. In this paper, we characterize the porous Ti6Al4V implant, which is one of the most promising and attractive biomedical applications due to the similarity of its modulus to human bones. We describe the mechanical properties of this implant, which we suggest is capable of providing important biological functions for bone tissue regeneration. We characterize a novel bionic design and fabrication process for porous implants. A design concept of "reducing dimensions and designing layer by layer" was used to construct layered slice and rod-connected mesh structure (LSRCMS) implants. Porous LSRCMS implants with different parameters and porosities were fabricated by selective laser melting (SLM). Printed samples were evaluated by microstructure characterization, specific mechanical properties were analyzed by mechanical tests, and finite element analysis was used to digitally calculate the stress characteristics of the LSRCMS under loading forces. Our results show that the samples fabricated by SLM had good structure printing quality with reasonable pore sizes. The porosity, pore size, and strut thickness of manufactured samples ranged from (60.95± 0.27)% to (81.23±0.32)%, (480±28) to (685±31) μm, and (263±28) to (265±28) μm, respectively. The compression results show that the Young's modulus and the yield strength ranged from (2.23±0.03) to (6.36±0.06) GPa and (21.36±0.42) to (122.85±3.85) MPa, respectively. We also show that the Young's modulus and yield strength of the LSRCMS samples can be predicted by the Gibson-Ashby model. Further, we prove the structural stability of our novel design by finite element analysis. Our results illustrate that our novel SLM-fabricated porous Ti6Al4V scaffolds based on an LSRCMS are a promising material for bone implants, and are potentially applicable to the field of bone defect repair.
Alloys ; Bionics ; Bone Substitutes/chemistry* ; Bone and Bones/pathology* ; Compressive Strength ; Elastic Modulus ; Finite Element Analysis ; Humans ; Lasers ; Materials Testing ; Maxillofacial Prosthesis Implantation ; Porosity ; Pressure ; Printing, Three-Dimensional ; Prostheses and Implants ; Prosthesis Design ; Stress, Mechanical ; Surgery, Oral/instrumentation* ; Tissue Engineering/methods* ; Titanium/chemistry*

OBJECTIVE: The aims of this study were to compare opening and closing angles of normally functioning mechanical aortic valves measured on dual-source computed tomography (CT) with the manufacturers' values and to compare CT-measured opening angles according to valve function. MATERIALS AND METHODS: A total of 140 patients with 10 different types of mechanical aortic valves, who underwent dual-source cardiac CT, were included. Opening and closing angles were measured on CT images. Agreement between angles in normally functioning valves and the manufacturer values was assessed using the interclass coefficient and the Bland-Altman method. CT-measured opening angles were compared between normal functioning valves and suspected dysfunctioning valves. RESULTS: The CT-measured opening angles of normally functioning valves and manufacturers' values showed excellent agreement for seven valve types (intraclass coefficient [ICC], 0.977; 95% confidence interval [CI], 0.962-0.987). The mean differences in opening angles between the CT measurements and the manufacturers' values were 1.2degrees in seven types of valves, 11.0degrees in On-X valves, and 15.5degrees in ATS valves. The manufacturers' closing angles and those measured by CT showed excellent agreement for all valve types (ICC, 0.953; 95% CI, 0.920-0.972). Among valves with suspected dysfunction, those with limitation of motion (LOM) and an increased pressure gradient (PG) had smaller opening angles than those with LOM only (p < 0.05). CONCLUSION: Dual-source cardiac CT accurately measures opening and closing angles in most types of mechanical aortic valves, compared with the manufacturers' values. Opening angles on CT differ according to the type of valve dysfunction and a decreased opening angle may suggest an elevated PG.
Adult ; Aortic Valve/*radiography ; Female ; Heart Valve Diseases/therapy ; *Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation/*instrumentation ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Tomography, X-Ray Computed/methods

The aim of this study was to investigate the pulsatile-flow performance in vitro of a new heart valve prostheses implanted with minimally invasive techniques (HVPMIT). Three HVPMITs were tested valves and another three original biological heart valve prostheses acted as reference valves. The pulsatile-flow parameters (including mean pressure drop, regurgitant percentage of stroke volume, and effective orifice area) were tested in a pulse duplicator according to the methods listed in ISO5840-2005 and GB 12279-2008. The results demonstrated that the regurgitant percentage of stroke volume of tested valves was up to 13%. It was significantly higher than that of the reference valves. This result suggested that paravalvular leakage had occurred in the tested valves. It was found in the further analysis that because HVPMIT was not sewn into the heart tissue when the HVPMIT was implanted in vivo and there was not a sewing ring in the HVPMIT, when tested valves were fixed in the pulse duplicator, some gaps might exist between the stent of HVPMIT and the fix gasket, and the paravalvular leakage could therefore take place through these gaps. This study demonstrated that there are significant differences in the shape, structure, fixation in vivo and clinical operational methods between HVPMIT and original biological heart valve prostheses. It is necessary to establish new test methods which adapt for HVPMIT to evaluate its pulsatile-flow performance according to its own features.
Animals ; Cardiac Catheterization ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; adverse effects ; instrumentation ; methods ; Minimally Invasive Surgical Procedures ; methods ; Prosthesis Design ; Pulsatile Flow

A 26-yr-old male patient reported worsened dyspnea, dizziness one year after an emergency Bentall operation for type A aortic dissection. There was evidence of hemolytic anemia and aortogram revealed a significant stenosis at the distal anastomosis site. During the reoperation, we found the inner felt at the distal anastomosis was inverted causing a significant stenosis. The reoperation successfully resolved this problem. Here, we report a rare case of hemolytic anemia caused by an inverted inner felt after Bentall operation.
Acute Disease ; Adult ; Anastomosis, Surgical ; Anemia, Hemolytic/*diagnosis/*etiology/surgery ; Aneurysm, Dissecting/complications/*surgery ; Aortic Aneurysm/complications/*surgery ; *Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation/*adverse effects/instrumentation ; Dizziness/etiology ; Dyspnea/etiology ; Echocardiography ; Humans ; Male ; *Postoperative Complications/surgery ; Reoperation ; Time Factors ; Tomography, X-Ray Computed ; Treatment Outcome

PURPOSE: To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. METHODS: An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. RESULTS: Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 +/- 2.17% vs. 50.48 +/- 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. CONCLUSIONS: Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.
Animals ; Corneal Endothelial Cell Loss/*prevention & control ; Descemet Stripping Endothelial Keratoplasty/*methods ; Lens Implantation, Intraocular/*instrumentation/*methods ; Lenses, Intraocular ; Models, Animal ; Postoperative Complications/*prevention & control ; Prosthesis Design ; Swine

PURPOSE: To investigate effects of a new push-through insertion method for donor lenticules using an injector system on endothelial viability ex vivo and in a clinical case series of endothelial keratoplasty. METHODS: An ex vivo delivery model was used with porcine corneoscleral rims. We compared the endothelial viability in a new push-through insertion method using the Visian Implantable Collamer Lens (ICL) injector versus that of standard forceps-assisted insertion for lenticule delivery. Twenty porcine corneal lenticules were divided into four groups by insertion method and wound size. Vital dye staining was performed and devitalized areas were semi-quantitatively assessed by digital imaging. In the clinical case series, Descemet's stripping endothelial keratoplasty (DSEK) using the push-through method was performed in seven patients and endothelial outcome was determined six months postoperatively. RESULTS: Mean devitalized areas for the push-through method were significantly lower than for forceps-assisted insertion through 3.2 mm incision (23.99 +/- 2.17% vs. 50.48 +/- 5.07%, p = 0.009) in the ex vivo model. Average endothelial cell counts of donor tissues of patients who underwent DSEK were 26.4% lower six months postoperatively. CONCLUSIONS: Push-through delivery of donor lenticules using the Visian ICL injector system appears to be less harmful to endothelial cells than conventional forceps-assisted delivery.
Animals ; Corneal Endothelial Cell Loss/*prevention & control ; Descemet Stripping Endothelial Keratoplasty/*methods ; Lens Implantation, Intraocular/*instrumentation/*methods ; Lenses, Intraocular ; Models, Animal ; Postoperative Complications/*prevention & control ; Prosthesis Design ; Swine

OBJECTIVE: To determine whether the introducer curving technique is useful in decreasing the degree of tilting of transfemoral Tulip filters. MATERIALS AND METHODS: The study sample group consisted of 108 patients with deep vein thrombosis who were enrolled and planned to undergo thrombolysis, and who accepted transfemoral Tulip filter insertion procedure. The patients were randomly divided into Group C and Group T. The introducer curving technique was Adopted in Group T. The post-implantation filter tilting angle (ACF) was measured in an anteroposterior projection. The retrieval hook adhering to the vascular wall was measured via tangential cavogram during retrieval. RESULTS: The overall average ACF was 5.8 +/- 4.14 degrees. In Group C, the average ACF was 7.1 +/- 4.52 degrees. In Group T, the average ACF was 4.4 +/- 3.20 degrees. The groups displayed a statistically significant difference (t = 3.573, p = 0.001) in ACF. Additionally, the difference of ACF between the left and right approaches turned out to be statistically significant (7.1 +/- 4.59 vs. 5.1 +/- 3.82, t = 2.301, p = 0.023). The proportion of severe tilt (ACF > or = 10degrees) in Group T was significantly lower than that in Group C (9.3% vs. 24.1%, chi2 = 4.267, p = 0.039). Between the groups, the difference in the rate of the retrieval hook adhering to the vascular wall was also statistically significant (2.9% vs. 24.2%, chi2 = 5.030, p = 0.025). CONCLUSION: The introducer curving technique appears to minimize the incidence and extent of transfemoral Tulip filter tilting.
Blood Vessel Prosthesis Implantation/instrumentation/*methods ; Chi-Square Distribution ; Device Removal ; Double-Blind Method ; Female ; Femoral Vein ; Humans ; Male ; Middle Aged ; Prosthesis Design ; Pulmonary Embolism/*prevention & control ; Statistics, Nonparametric ; Thrombolytic Therapy ; Treatment Outcome ; *Vena Cava Filters ; Venous Thrombosis/*complications

Transcatheter aortic valve implantation and transcatheter mitral valve repair (MitraClip) procedures have been performed worldwide. In this paper, we review the use of two-dimensional and three-dimensional transesophageal echo for guiding transcatheter aortic valve replacement and mitral valve repair.
Aged ; Aged, 80 and over ; Aortic Valve Stenosis/*therapy/*ultrasonography ; Balloon Valvuloplasty ; Bioprosthesis ; *Cardiac Catheterization/adverse effects/instrumentation ; *Echocardiography ; Echocardiography, Doppler, Color ; Echocardiography, Three-Dimensional ; Echocardiography, Transesophageal ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation/adverse effects/instrumentation/*methods ; Humans ; Mitral Valve Insufficiency/*therapy/*ultrasonography ; Predictive Value of Tests ; Prosthesis Design ; Severity of Illness Index ; Surgical Instruments ; Ultrasonography, Interventional/*methods

OBJECTIVE: To explore the effect of a new triple-branched aortic arch covered stent graft on DeBakey Type I aortic dissection, and to assess its efficacy in comparison with traditional surgery. METHODS: From January 2010 to November 2010, 38 patients of DeBakey Type I aortic dissection were treated surgically in the Second Xiangya Hospital of Central South University, in which 16 operations used triple-branched aortic arch covered stent grafts (stent graft group, SG group), 22 operations used traditional 4 sides branches aortic arch grafts (arch graft group, AG group). RESULTS: Compared with AG group, the cardiopulmonary bypass time[(138.1± 56.42) vs (179.21± 67.64) min], the clamp time [(98.56±28.08) vs (134.36±46.46) min] and the selective cerebral perfusion time[(27.3±14.76) vs (48.74±18.22) min] in SG group were obviously shortened(P<0.05). The volume of drainage 24 hours after operation in SG group also reduced[(608.93±308.15) vs (899.04±437.79) mL](P<0.05). The SG group had a lower rate of recurrent laryngeal nerve injury (6.25% vs 27.3%) and duration of hospitalization[(16.15±6.68) vs (21.18±12.69) d](P<0.05). During a following-up period of 14 to 24 months,reexamination of aortic CT angiography showed that the triple-branched aortic arch covered stent graft expanded well, and attached to the wall satisfactorily, while the corresponding false lumen of the aortic artery disappeared and the distal false lumen was filled with thrombus. The life quality of patients were good. CONCLUSION The new triple-branched aortic arch covered stent graft is appropriated for most patients with DeBakey Type I aortic dissection. Its use can simplify the aortic arch procedure,decrease the operation risk and has satisfactory results in early and middle stage after operation.
Adult ; Aneurysm, Dissecting ; surgery ; Aorta, Thoracic ; surgery ; Aortic Aneurysm ; surgery ; Blood Vessel Prosthesis Implantation ; instrumentation ; methods ; Cardiopulmonary Bypass ; Female ; Humans ; Male ; Middle Aged ; Stents ; Treatment Outcome

The present paper was conducted to a systematic method of surgical guide for dental implant based on computer-aided technology through CT data and dental-cast data. By analyzing the patient's CT data, the implant region was planned using image processing techniques. For the specified implant region, the computer-aided method for the rational allocation of dental implant was addressed in a sense of anatomy. With biomechanical principles as well as aesthetical and functional requirements as preconditions, this method can make full use of bone quantity and quality to produce the optimum implantation axis. The transferring of implant planning to the patient was then realized by registration between CT models and dental-cast models. A case research explained the whole process of the surgical guide. The results validated the correctness and feasibility of this method, which has a great significance to enhance the quality and accuracy of implant surgery.
Computer-Aided Design ; Dental Implantation, Endosseous ; instrumentation ; methods ; Dental Models ; Dental Prosthesis Design ; instrumentation ; methods ; Humans ; Oral Surgical Procedures, Preprosthetic ; methods ; Patient Care Planning ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed