ObjectiveTo review the current research status of in situ three-dimensional (3-D) printing technique and future trends. MethodsRecent related literature about in situ 3-D printing technique was summarized, reviewed, and analyzed. ResultsBased on the cl inical need for surgical repair, in situ 3-D printing technique is in the preliminary study, mainly focuses on in situ dermal repair and bone and cartilage repair, and succeeds in experiments, but there are still a lot of problems for cl inical application. ConclusionWith the development of in situ 3-D printing technique, it will provide patients with real-time and in situ digital design and 3-D printing treatment with a timely and minimally invasive surgical repair process. It will be widely used in the future.
ObjectiveTo evaluate liver perfusion in pregnant women with hepatitis between 13 and 41 weeks of gestation by three-dimensional color power Doppler angiography (3D-CPA) vascular indexes. MethodsThis study involved 73 pregnant women with hepatitis and 44 healthy pregnant women who had the pregnancy examination between February 2012 and June 2013. We sampled in the area which was near the right lobe of the pregnant women liver's portal vein branch, and obtained the vascularization index (VI), flow index (FI) and vascularization flow index (VFI) via the virtual organ computer-aided analysis (VOCAL) method. Then, we compared the liver perfusion differences between the pregnant women with hepatitis and healthy pregnant women. ResultsThe hepatic flow indexes obtained by 3D-CPA were significantly different between the HBV-DNA viral load and the control groups. The cutoff values of the three vascular indexes of patients with hepatitis with HBV-DNA viral load and the healthy pregnant women were respectively VI=8.760 (P<3×10-4); FI=22.180 (P<6×10-7); and VFI=1.575 (P<3×10-5). ConclusionApplication of the 3D-CPA on liver perfusion may differentiate pregnant women with hepatitis B from normal ones, thus offer a support for clinical prevention and treatment for pregnant women with hepatitis B.
Objective To introduce the recent advances of the application of computer technology in tissue engineering. Methods The recent original articlesrelated to computer technology, medical image technology, computer-aided design, the advanced manufacture technology were summarized and systematically analyzed.Results Computer-aided tissue engineering is a new fieldon tissue engineering. It is the future direction of tissue engineering study. This article reviews recent development of medical CT/MRI scanning, three-dimensional reconstruction, anatomical modeling, computeraided design, computer-aided manufacturing, rapid prototyping， RP manufacturing of tissue engineering scaffolds and computeraided implantation.Conclusion Computer-aided tissue engineering can be used in scaffolds design and fabrication, computer-aided artificial tissue implantation. It is a new field on tissue engineering.
【Abstract】 Objective To observe the distribution feature of nerve bundles in C7 nerve anterior and posterior division end. Methods The brachial plexus specimen was harvested from 1 fresh adult cadaver. After C7 nerve was confirmed, the distal end of anterior and posterior division was dissected and embedded by OCT. Then the samples were serially horizontally sliced with each 10 μm deep. After acetylcholinesterase (AChE) histochemical staining, the stain characteristics of different nerve fiber bundles were observed and amount of the nerve fiber bundles were counted under optic-microscope. At last, the imaging which were collected were three-dimensional (3-D) reconstructed by using Amira 4.1 software. Results There was no obvious difference in the stain between the anterior and posterior divisions. The running of the nerve fiber bundles were dispersive from proximal end of nerve to distal end of nerve. Nerve fiber bundles of anterior division were mainly sensor nerve fiber bundles, which located in medial side. Nerve fiber bundles of posterior division were mainly moter nerve fiber bundles, having no regularity in the distribution of nerve fiber bundles. The total number of nerve fiber bundles in distal end of anterior division was 7.85 ± 1.04, the number of motor nerve fiber bundles was 2.85 ± 0.36, and the number of sensor nerve fiber bundles was 5.13 ± 1.01. The total number of nerve fiber bundles in distal end of posterior division was 9.79 ± 1.53, the number of motor nerve fiber bundles was 6.00 ± 0.69, and the number of sensor nerve fiber bundles was 3.78 ± 0.94. There were significant differences in the numbers of motor and sensor nerve fiber bundles between anterior and posterior divisions (P lt; 0.05). The microstructure 3-D model was reconstructed based on serial slice through Amira 4.1. The intercross and recombination process of nerves bundles could be observed obviously. The nerve bundle distribution showed cross and combination. Conclusion Nerve fiber bundles of anterior division are mainly sensor nerve fiber bundles and locate in medial side. Nerve fiber bundles of posterior division are mainly motor nerve fiber bundles, which has no regularity in the distribution of nerve fiber bundles. The 3-D reconstruction can display the internal structure feature of the C7 division end.
【Abstract】 Objective To determine the three-dimensional stabil ity of atlantoaxial reconstruction withanterior approach screw fixation through C2 vertebral body to C1 lateral mass and Gall ie’s technique (ASMG) for C1,2instabil ity. Methods Twenty-five human cadaveric specimens (C0-3 ) were divided randomly into 5 groups (n=5). Thethree-dimensional ranges of motion C1 relative to C2 were measured under the five different conditions：the intact state group (group A), type II odontoid fracture group (group B), posterior C1,2 transarticular screw fixation group (group C), ASM group (group D) and ASMG group (group E). The three-dimensional ranges of motions C1 relative to C2 by loading ± 1.5 Nm were measured under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation. The obtained data was statistically analyzed. Results In each group, the three-dimensional ranges of motion C1 relative to C2 under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation were as follows: in group A (8.10 ± 1.08), (8.49 ± 0.82), (4.79 ± 0.47), (4.93 ± 0.34), (28.20 ± 0.64), (29.30 ± 0.84)°; in group B (13.60 ± 1.25), (13.80 ± 0.77), (9.64 ± 0.53), (9.23 ± 0.41), (34.90 ± 0.93), (34.90 ± 1.30)°; in group C (1.62 ± 0.10), (1.90 ± 0.34), (1.25 ± 0.13), (1.37 ± 0.28), (0.97 ± 0.14), (1.01 ± 0.17)°; in group D (2.03 ± 0.26), (2.34 ± 0.49), (1.54 ± 0.22), (1.53 ± 0.30), (0.80 ± 0.35), (0.76 ± 0.30)°; in group E (0.35 ± 0.12), (0.56 ± 0.34), (0.44 ± 0.15), (0.55 ± 0.16), (0.43 ± 0.07), (0.29 ± 0.06)°. Under the six conditions, there were generally significant differences between group A and other four groups, and between group B and groups C, D and E (P lt; 0.001), and between group E and groups C, D in flexion/ extension and left/right lateral bending (P lt; 0.05). There was no significant difference between group E and groups C, D in left/right axial rotation (P gt; 0.05). Conclusion In vivo biomechanical studies show that ASMG operation has unique superiority in the reconstruction of the atlantoaxial stabil ity, especially in controll ing stabil ity of flexion/extension and left/right lateral bending, and thus it ensures successful fusion of the implanted bone. It is arel iable surgical choice for the treatment of the obsolete instabil ity or dislocation of C1, 2 joint.
ObjectiveTo explore potential value of three-dimensional reconstruction technique for preoperative evaluation of hepatic alveolar echinococcosis. MethodsTwenty-one cases of hepatic alveolar echinococcosis proved by postoperative pathological examination in Affiliated Hospital of Qinghai University from October 2013 to March 2014 were analyzed retrospectively. The three periods of patients’ liver dynamic thin layerCTscan images were collected and imported in three-dimensional reconstruction software by DICOM format. The volume of the virtual resected liver tissue was calculated by software, and then was compared with the actual resected liver tissue volume. ResultsThe resected liver volume was (761.94±505.77) mL and (756.19±501.78) mL in the virtual surgery and in the veritable surgery, respectively. The proportion of resected liver in the total liver was (39.27±18.75)% and (38.95±16.99)% in the virtual surgery and in the veritable surgery, respectively. The resected liver volume had no significant difference between the virtual surgery and veritable surgery (P>0.05), which a positive relation (r=0.989, P<0.001). ConclusionThe limited preliminary data in this study show that three-dimensional reconstruction technique and virtual planning system for surgery could accurately guide resection of lesion and provide preoperative guidance of accurate liver resection for hepatic alveolar echinococcosis.
ObjectiveTo prepare bionic spinal cord scaffold of collagen-heparin sulfate by three-dimensional (3-D) printing, and provide a cell carrier for tissue engineering in the treatment of spinal cord injury. MethodsCollagen-heparin sulfate hydrogel was prepared firstly, and 3-D printer was used to make bionic spinal cord scaffold. The structure was observed to measure its porosity. The scaffold was immersed in simulated body fluid to observe the quality change. The neural stem cells (NSCs) were isolated from fetal rat brain cortex of 14 days pregnant Sprague-Dawley rats and cultured. The experiment was divided into 2 groups: in group A, the scaffold was co-cultured with rat NSCs for 7 days to observe cell adhesion and morphological changes;in group B, the NSCs were cultured in 24 wells culture plate precoating with poly lysine. MTT assay was used to detect the cell viability, and immunofluorescence staining was used to identify the differentiation of NSCs. ResultsBionic spinal cord scaffold was fabricated by 3-D printer successfully. Scanning electron microscope (SEM) observation revealed the micro porous structure with parallel and longitudinal arrangements and with the porosity of 90.25%±2.15%. in vitro, the value of pH was not changed obviously. After 8 weeks, the scaffold was completely degraded, and it met the requirements of tissue engineering scaffolds. MTT results showed that there was no significant difference in absorbence (A) value between 2 groups at 1, 3, and 7 days after culture (P>0.05). There were a lot of NSCs with reticular nerve fiber under light microscope in 2 groups;the cells adhered to the scaffold, and axons growth and neurosphere formation were observed in group A under SEM at 7 days after culture. The immunofluorescence staining observation showed that NSCs could differentiated into neurons and glial cells in 2 groups;the differentiation rate was 29.60%±2.68% in group A and was 10.90%±2.13% in group B, showing significant difference (t=17.30, P=0.01). ConclusionThe collagen-heparin sulfate scaffold by 3-D-printed has good biocompatibility and biological properties. It can promote the proliferation and differentiation of NSCs, and can used as a neural tissue engineered scaffold with great value of research and application.
ObjectiveTo investigate the value of diffusion weighted imaging (DWI) combined with three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) in evaluating metastatic lymph nodes secondary to hilar cholangiocarcinoma. MethodsFrom July 2009 to March 2011, DWI examination was performed in 37 patients with hilar cholangiocarcinoma, which was compared with 3D-VIBE sequences. The morphological characteristics and distribution were analyzed for metastatic and nonmetastatic lymph nodes. Signal intensity (SI) was measured on DWI images and apparent diffusion coefficient (ADC) was calculated for each lymph node. The SI of lymph nodes (SILN） and liver (SIliver) were also measured and the ratio of SI was calculated. The ADC and the ratio of SI were compared between metastatic and nonmetastatic lymph nodes. ResultsThere were fifty-nine groups of lymph nodes in 37 patients with hilar cholangiocarcinoma, fifty-one groups were revealed in both DWI and 3D-VIBE sequences, and eight groups were only demonstrated in one sequence (P=0.070). The short diameters were (1.05±0.42) cm and (0.78±0.22) cm on 3D-VIBE images for metastatic and nonmetastatic lymph nodes, respectively (P=0.030). The ADC value in metastatic lymph nodes was (1.64±0.3)×10-3 mm2/s, which was significantly lower than that in nonmetastatic lymph nodes 〔(2.28±0.79)×10-3 mm2/s〕 on DWI images (P=0.033). There were no significant differences in SILN/SIliver between metastatic and nonmetastatic lymph nodes on images of portal venous phase and 3 min delayed contrast-enhanced phase. ConclusionsDifferences of ADC and short diameter can provide valuable information to differentiate metastatic lymph nodes with nonmetastatic lymph nodes. When combined with 3D-VIBE sequence, DWI is more effective in evaluating metastatic lymph nodes secondary to hilar cholangiocarcinoma.
ObjectiveTo review the research progress of three-dimensional (3D) bioprinting technology for wound dressing design and preparation. Methods The literature on 3D bioprinted wound dressings in recent years, both domestically and internationally, was retrieved. The core principles of 3D bioprinting technology, mainstream methods, and their applications in wound dressings design and preparation were summarized. Results By leveraging precise spatial manipulation capabilities and multi-material integration, 3D bioprinting technology constructs the functionalized wound dressings with complex structures and bioactivity. These dressings primarily function across several dimensions: wound hemostasis, infection control, controlled drug release, and monitoring wound healing. Conclusion Although 3D bioprinted wound dressings can promote wound healing through multiple dimensions, large-scale clinical validation is still lacking. Future efforts should further clarify their clinical value and scope of application to provide more efficient, precise, and patient-comfortable treatment options for refractory wounds.
Objective To evaluate the feasibil ity and cl inical significance of the computed tomography angiography (CTA) for the latissimus dorsi muscle (LDM) flap transplantation. Methods From September 2007 to August 2008, 3 cases of soft tissue defects in l imbs were treated with LDM flap transplantation. Three patients included 2 males and 1 female whowere 23 to 42 years old. All of soft tissue defects were caused by trauma. The locations were the forearm in 2 cases and the leg in 1 case. The area of defect was 17 cm × 8 cm-20 cm × 10 cm. All cases received CTA to observe the distribution and anastomosis of thoracodorsal artery. Subsequently, three-dimensional computer reconstruction were carried out to display the stereoscopic structure of the LDM flap and to design the LDM flap before operation. Results The anatomy characteristic of LDM flap can be displayed accurately by the three-dimensional reconstruction model. The distribution of thoracodorsal artery in 3 cases of flaps was in concordance with preoperative design completely. All the flaps were excised successfully, the area of the flap was 19 cm × 10 cm-22 cm × 12 cm. All the transferred flaps survived completely. All cases were followed up from 4 months to 12 months. The color and texture of the flaps were good. Conclusion The three-dimensional reconstructive images can provide visible, stereoscopic and dynamic anatomy for cl inical appl ication of LDM flap. The digitized three-dimensional reconstructive models of LDM flap structures can be appl ied in cl inical training and pre-operative design.