This paper is aimed to develop a computerized three dimensional system for displaying and analyzing mandibular helical axis pathways. Mandibular movements were recorded using a six-degrees-of-freedom ultrasonic jaw movement recording device. The three-dimensional digital models of the midface and the mandible were reconstructed and segmented from CT skull images. The digital models were then transformed to the coordinate system of mandibular motion data by using an optical measuring system. The system was programmed on the base of the Visualization ToolKit and Open Scene Graphics Library. According to the motion data, transformation matrices were calculated to simulate mandibular movements. Meanwhile, mandibular helical axis pathways were calculated and displayed three dimensionally by means of an eigenvalues method. The following parameters of mandibular helical axis were calculated: the rotation around instantaneous helical axis, the translation along it, its spatial orientation, its position and distance relative to any special reference point. These parameters could be exported to describe comprehensively the whole mandiblular movements. It could be concluded that our system would contribute to the study of mandiblular helical axis pathways.
ObjectiveTo study the preparation method of acellular dermal matrix (ADM) for cartilage tissue engineering and analyze its biocompatibility. MethodsThe dermal tissues of the calf back were harvested, and decelluarized with 0.5% SDS, and the ADM was reconstructed with 0.5% trypsin, cross-linked with formaldehyde, and modified with 0.5% chondroitin sulfate which can promote the proliferation of chondrocytes. And the porosity, cytotoxicity, and biocompatibility were determined. Co-cultured 2nd passage chondrocytes and bone marrow stromal cells in a proportion of 3 to 7 were used as seed cells. The cells were seeded on ADM (experimental group) for 48 hours to observe the cell adhesion. The expressions of mRNA and protein of collagen type Ⅱ were tested by RT-PCR and Western blot methods, respectively. And the expressions were compared between the cells seeded on the scaffold and cultured in monolayer (control group). ResultsAfter modification of 0.5% trypsin, the surface of ADM was smooth and had uniform pores; the porosity (85.4%±2.8%) was significantly higher than that without modification (72.8%±5.8%) (t=-4.384, P=0.005). The cell toxicity was grade 1, which accords to the requirements for cartilage tissue engineering scaffolds. With time passing, the number of inflammatory cells decreased after implanted in the back of the rats (P<0.05). The scanning electron microscope observation showed that lots of seed cells adhered to the scaffold, the cells were well stacked, displaying surface microvilli and secretion. The expressions of mRNA and protein of collagen type Ⅱ were not significantly different between experimental and control groups (t=1.265, P=0.235;t=0.935, P=0.372). ConclusionThe ADM prepared by acellular treatment, reconstruction, cross-linking, and modification shows perfect characters. And the seed cells maintain chondrogenic phenotype on the scaffold. So it is a proper choice for cartilage tissue engineering.
ObjectiveTo evaluate the validity of European System for Cardiac Operative Risk Evaluation (EuroSCORE) Ⅱ for predicting in-hospital mortality and prolonged ICU stay after Sun's procedure (total aortic arch replacement with stented elephant trunk implantation) for Stanford type A aortic dissection (STAAD). MethodsClinical data of 384 STAAD patients undergoing Sun's procedure in Beijing Anzhen Hospital between February 2009 and February 2012 were retrospectively analyzed, including 228 (59.38%) patients with acute STAAD. Accoding to EuroSCORE Ⅱ to predict postoperative mortality, all the patients were divided into a low-risk group, a medium-risk group, a high-risk group and an extremely-high-risk group. There were 296 patients including 52 females in the low-risk group with their age of 45.39±10.75 years, 70 patients including 19 females in the medium-risk group with their age of 47.67±11.26 years, 13 patients including 5 females in the high-risk group with their age of 53.08±4.94 years, and 5 patients including 1 female patient in the extremely-high-risk group with their age of 41.60±11.08 years. All the patients received Sun's procedure under deep hypothermic circulatory arrest and antegrade selective cerebral perfusion. EuroSCORE Ⅱ was used to predict postoperative mortality and prolonged ICU stay. ResultsIn-hospital mortality was 8.07% (31/384). Mean length of ICU stay was 3.06 days. Length of ICU stay of 42 patients was longer than 7 days. For low-risk group, the predicted mortality was lower than the actual mortality. For medium-risk, high-risk and extremely-high-risk groups, the predicted mortality was higher than the actual mortality. EuroSCORE Ⅱ showed unsatisfactory discriminatory ability to predict postoperative mortality and prolonged ICU stay. The area under ROC curve were 0.49 and 0.52 respectively. The calibration was also poor for predicting postoperative mortality and prolonged ICU stay (P<0.001). ConclusionsEuroSCORE Ⅱ is not satisfactory for predicting mortality and prolonged ICU stay after Sun's procedure for the treatment of STAAD. A new risk evaluating system specific for STAAD is needed.
ObjectiveTo summarize clinical experience and surgical indications of open stented elephant trunk (sET) procedure for the treatment of complex acute Stanford type B aortic dissection (AD). MethodsFrom February 2009 to April 2013, 25 patients with complex acute Stanford type B AD underwent open sET procedure in Beijing Anzhen Hospital. There were 22 male and 3 female patients with their age of 46.92±9.12 years (range, 30 to 66 years). There were 16 patients with hypertension and 3 patients with preoperative acute renal failure. All the patients received sET implantation via an aortic arch incision under deep hypothermic circulatory arrest. Concomitant procedures included extra-anatomic bypass grafting in 11 patients, Bentall procedure in 1 patient, aortic valve replacement in 3 patients, and ascending aorta plasty in 3 patients. Computed tomography angiography (CTA) was performed before discharge and during follow-up for all the patients. ResultsOperation time was 4-7 (5.5±0.7) hours, cardiopulmonary bypass time was 93-206 (137.64±30.02) minutes, aortic cross-clamping time was 28-109 (57.96±21.05) minutes, and selective cerebral perfusion time was 15-76 (26.76±11.88) minutes. There was no in-hospital death. Postoperatively, there were 2 patients with pulmonary complications, 2 patients with type I endoleak, 1 patient with acute renal failure, 1 patient with temporary neurological disorder, 1 patient with sudden ventricular fibrillation, and 1 patient with delayed wound healing. Mean follow-up time was 6-54 (25.76±16.15) months, and 2 patients were lost during follow-up. The follow-up rate was 92%.There was no late death during follow-up. ConclusionsOpen sET procedure is a reliable and efficacious therapeutic strategy for patients with complex acute Stanford type B AD. Surgical indications include complex Stanford type B AD without enough landing zone, type B AD with ascending aortic disease, aortic root disease, valvular heart disease, coronary artery disease and congenital heart defects, and type B AD caused by genetic connective tissue disorder.
ObjectiveTo summarize our experience and clinical effect of surgical treatment of Stanford type A aortic dissection (TAAD) involving an aberrant right subclavian artery (ARSA). MethodsFrom March 2009 to January 2016, 14 patients with TAAD involving an ARSA (acute TAAD, n=10; chronic TAAD, n=4) underwent operation under hypothermic cardiopulmonary bypass combined with selective antegrade cerebral perfusion in our center. There were 11 male and 3 female patients with a mean age of 46.07±8.45 years. A total of 13 patients (13/14, 92.86%) underwent stented elephant trunk procedure combined with total arch replacement (Sun's procedure). The remaining patient (1/14, 7.14%) underwent partial aortic arch replacement combined with Bentall procedure without ARSA revascularization. ResultsThe average operation time, cardiopulmonary bypass time, aortic cross-clamping time and selective cerebral perfusion time was 7.89±1.80 h, 208.43±28.84 min, 117.64±23.30 min, and 30.50±10.15 min, respectively. No operation-related deaths occurred. However, two (14.29%) patients died on postoperative 5 d, 7 d, respectively in hospital. One patient required repeat thoracotomy for bleeding, one suffered temporary renal dysfunction and one renal failure (this patient had renal failure before surgery). The mean follow-up was 28.42±22.52 months with a follow-up rate of 100.00% (12/12). One patient died of heart failure and renal failure at 64 months after operation. The others were free from any aortic complications during follow-up. ConclusionsTAAD involving an ARSA should be clearly diagnosed before surgery, and treated by the optimal arterial cannulation and cerebral perfusion during operation. Repair of aortic dissection with Sun's procedure and revascularization of the ARSA can obtain satisfactory clinical outcomes in patients with TAAD involving an ARSA.
ObjectiveTo investigate the effect of KLD-12 polypeptide complexed with recombinant human bone morphogenetic protein 2 (rhBMP-2) on osteogenic activity of rabbit bone marrow mesechymal stem cells (BMSCs). MethodsBone marrow was harvested from 3-month-old New Zealand white rabbit, and density gradient method was used to isolate and culture BMSCs. The third generation BMSCs were used for three-dimensional culture of KLD-12 polypetide/rhBMP-2 in vitro (experimental group) and KLD-12 polypeptide (control group). The morphology of the cells in the gel was observed by inverted phase contrast microscope at 7 days; alkaline phosphatase (ALP) and osteocalcin protein content were dectected at 3, 7, 10, 14, and 21 days; collagen type I immunofluorescence staining was done and real-time fluorescent quantitative PCR was performed to detect the relative expression of collagen type I and osteocalcin gene at 14 days. ResultsUnder the inverted phase contrast microscope, the BMSCs in the gel of the experimental group and the control group showed circular growth, and the distribution was uniform at 7 days. There was no significant difference in the expressions of ALP and osteocalcin protein content between 2 groups at 3 and 7 days (P > 0.05); the above indexes in experimental group were significantly higher than those in the control group at 10-21 days (P < 0.05). Laser scanning confocal microscope observation showed that immunofluorescence staining for collagen type I was positive in the experimental group, and the expression was higher than that in the control group at 14 days. Real-time fluorescence quantitative PCR detection showed that the collagen type I and osteocalcin gene expressions were significantly higher than those in the control group (t=15.902, P=0.000; t=12.998, P=0.000). ConclusionBMSCs can normally grow and proliferate in the KLD-12 polypeptide, and KLD-12 polypeptide/rhBMP-2 has good biological activity to induce BMSCs differentiation into osteoblasts.