The effects of the autologous venous external stents on intimal hyperplasia of the vein grafts in rabbits / 中华外科杂志

<p><b>OBJECTIVE</b>To assess the effect of the autologous venous external stents on intimal hyperplasia of the vein grafts in rabbits.</p><p><b>METHODS</b>Thirty-six male New Zealand white rabbits, aged 5 months and weighing 2.8 to 3.0 kg, were randomly divided into 3 groups: group A, group B and group C, with 12 rabbits in each group. First, a section about 6 cm long of vein was cut from the right external jugular vein of each rabbit and severed to have 3 equal-length segments. Next, each distal segment prepared for anastomosis. The proximal segment invaginating middle segment in group A and only middle segment in group B were used for the external stent. Later, the left common carotid artery was separated from surrounding tissue, from it a section about 0.5 cm long was cut away. Finally, the vein graft was inverted and end-to-end anastomosed to the two ends of the artery with a 9-0 suture. After bloodstream re-established, the diameter of each vein graft was measured. At 2 and 4 weeks postoperative, the graft veins were cut off and histologically examined by the means of HE staining and Masson staining. The smooth muscle cells (SMC) proliferation was studied by the immunohistochemical detection of proliferating cell nuclear antigen.</p><p><b>RESULTS</b>After bloodstream re-established, the diameters of vein graft of group A and group B and group C were (1.6 +/- 0.3) mm, (2.2 +/- 0.4) mm and (2.6 +/- 0.6) mm respectively (P < 0.05). At 4 weeks postoperative, the data of the ratio of intima to media thickness and the index of the proliferating cells of the intima were as follow: group A (1.01 +/- 0.07 and 6.84 +/- 1.98), group B (1.32 +/- 0.08 and 11.01 +/- 2.61), group C (1.55 +/- 0.03 and 14.96 +/- 4.14). Both the data of group A were obviously less than that in group B, and that of group B was less than group C (P < 0.05).</p><p><b>CONCLUSION</b>The autologous venous two-layer external stents inhibit intimal hyperplasia of the vein grafts.</p>

Biomechanical study on the calcaneal fracture fixed by the self-designed calcaneal anatomical plate and pre-cut gudgeon / 中国骨伤

<p><b>OBJECTIVE</b>To study the biomechanical properties of self-designed calcaneal anatomical plate and pre-cut gudgeon system and its efficacy for calcaneal fracture fixation.</p><p><b>METHODS</b>Sixteen fresh foot specimens were randomly divided into experimental group and the control group. Axial compressive load were applied to all specimens in order to create a calcaneal fracture model, and the maximum load and the maximum arch displacement of experimental group were recorded. In experimental group, self-designed intenal fixation system were utilized, while the AO plate internal fixation system were utilized in the control group. Axial compressive test were applied again to both groups, and the maximum load, the foot arch displacement and calcanus broadens were measured and recorded.</p><p><b>RESULTS</b>Comparison between before and after fixing the calcaneus fracture by self-designed internal fixation system in experimental group, the difference of the maximum load was significant (P<0.01), but there was no significant difference (P>0.05) of the maximum arch displacement. All parameters were significantly different (P<0.01) between the experimental group and the control group.</p><p><b>CONCLUSION</b>The fractured calcaneus will be able to regain normal foot biomechanical function after treated by self-designed internal fixation system, and able to support foot arch to bear great load. The self-designed internal fixation and pre-cut gudgeon system is considered to outperform the conventional AO internal fixation system with its better effectiveness and outcome in treating calcaneus fractures.</p>