Internal and external responses of anterior lumbar/lumbosacral fusion: nonlinear finite element analysis

STUDY DESIGN: Determination of external and internal responses of the human lumbosacral spine using a validated 3-dimensional finite element model. OBJECTIVE: The objective of the present study was to evaluate the range of motion, disc stress, and facet joint pressure owing to anterior fusion at L4-L5 or L5-S1 level and compare with the intact spine. SUMMARY OF BACKGROUND DATA: A significant majority of finite element models of anterior lumbar interbody fusion are primarily focused on upper and middle levels, whereas lower spinal levels are most commonly treated with surgery. METHODS: A 3-dimensional L4-S1 finite element model, validated in the entire nonlinear range of the moment-rotation response, was used to determine ranges of motion, disc stress, and facet joint contact pressure under normal and 2 surgical conditions with bone graft and porous tantalum. Biomechanical responses were compared under flexion and extension loading between the 2 fusions and fusion masses and at the fused and intact segments. RESULTS: Moment-rotation responses were nonlinear under all conditions. The range of motion at the caudal level was greater than the range of motion at the rostral level in the intact spine. The range of motion of the L4-S1 spine decreased more with the caudal than rostral fusion and more with the tantulum than bone under both loading modes. Facet joint pressures increased more with the rostral than caudal fusion. Stresses in the adjacent disc were greater with the caudal than rostral fusion under both modes of loading. CONCLUSIONS: At the fused level, the caudal fusion imparted additional rigidity under flexion to the lumbosacral joint. Both fusion masses added flexibility to the adjacent segment. Under both fusion masses, increased facet joint pressure in the lumbosacral joint indicates the susceptibility of this transitional joint to long-term biomechanics-induced consequences. Increased facet joint pressures with the rostral fusion indicate that the posterior complex responds with increased load sharing, and may predispose the spine to facet-related arthropathy. Increased stresses in the adjacent disc with the caudal fusion under both modes of loading imply the potential to disc-related changes owing to long-term physiologic loading.     

体外重建受损或畸形肾血管在肾脏移植中的应用

目的探讨体外修复重建受损或畸形供肾血管对肾脏移植临床效果的影响。方法对11例供。肾有血管损伤或畸形的肾移植资料进行回顾性分析，并以同期进行的20例正常供肾肾移植病例作为对照组。体外血管重建的方法包括动脉端端吻合（3例）、端侧吻合（3例）、侧侧共干吻合（2例）、利用供体或受体髂动脉及其分支合并及延长供。肾动脉（3例）。结果术后平均随访2年，两组患者均存活；血管重建组2例而对照组3例患者术后新出现高血压或高血压加重（P=0．595），但未发现移植肾动脉狭窄；血管重建组和对照组术后肾功能延迟恢复发生率为27．3％和20％（P=0．484），急性排斥反应发生率分别为9．1％和10．0％（P=0．719）；术后1年两组内有移植肾患者的血肌酐水平分别为（110±21）和（107±23）9μmol／L（P=0．664），两组间差异无显著性。结论选择合适方法进行体外修复重建供肾受损或畸形的血管，不会影响肾移植的效果，并可以大大提高供体器官的利用率。     

肾移植术后并发泌尿系统肿瘤的相关因素与临床干预

目的:探讨肾移植术后并发泌尿系统肿瘤的相关因素与临床干预措施.方法:报告9例(10次)此种患者的临床资料.9例肾移植术后均行免疫抑制治疗.肿瘤均发生在自体肾、输尿管和膀胱:肾透明细胞癌、肾肉瘤和膀胱腺癌各1例,肾盂输尿管膀胱移行细胞癌6例,其中1例先发生膀胱腺癌后又发生肾盂输尿管移行细胞癌.肿瘤发生于移植术后8～146个月,且8例发生在应用新型免疫抑制剂之后.患者均有服用龙胆泻肝丸或冠心苏合丸史.8例接受了根治性手术,1例未能手术切除.结果:9例随访8～44个月,未能手术切除1例于术后5个月肝转移死亡.1例肉瘤复发后放弃治疗后死亡.1例膀胱肿瘤复发,行膀胱全切腹壁造瘘术,1例腺癌已出现肺和胸膜转移.另5例最后随访时存活良好.结论:肾移植术后并发泌尿系统肿瘤以移行细胞癌为多;可能与服用含马兜铃的中药和应用新型免疫抑制剂有关;根治性手术治疗、减少免疫抑制剂用量和更换免疫抑制剂种类是主要临床干预措施.     

固定矫治器在颌骨骨折复位恢复咬骀关系时的作用

目的探讨固定正畸技术治疗颌骨骨折手术复位时恢复正常咬骀关系的作用。方法利用方丝弓矫治器作为牙弓夹板对颌骨外伤患者进行术中颌关系复位、术后颁关系调整，观察其疗效。结果方丝弓矫治器治疗后，牙及颌骨复位精确，咬殆关系恢复佳，并发症少。结论固定矫治器对确定颌骨骨折手术时的咬骀关系有良好的作用，技术安全可靠。     

Research of PDGF-BB gel on the wound healing of diabetic rats and its pharmacodynamics

BACKGROUND: One of the leading causes of impaired wound healing is diabetes mellitus. In diabetic patients, a minor skin wound often leads to serious complications. Many experiments had demonstrated that the expression of platelet-derived growth factor (PDGF) and its receptor was decreased in wounds of healing-impaired diabetic mice, indicating that a certain expression level of PDGF is essential for normal repair. MATERIALS AND METHODS: The diabetic rats was induced by a single i.p. injection of streptozotocin and a 1.8 cm diameter full-thickness wound was made on each side of the rat mid-back. Then the rats were randomly divided into five groups, with eight animals in each group as follows: blank control, vehicle control, 3.5 microg PDGF-BB/cm(2) treatment group, 7 microg PDGF-BB/cm(2) treatment group and 14 microg PDGF-BB/cm(2) treatment group for either 7 or 14 consecutive days after wounding. Re-epithelialization area was measured by computerized planimetry, percentage wound closure and percentage wound contraction was calculated, granulation tissue and collagen formation was assessed by Masson trichrome, cell proliferation (proliferating cell nuclear antigen staining) and angiogenesis (Factor VIII related antigen staining) was assessed by immunohistological methods. RESULTS: PDGF-BB treatment improved healing quality, enhanced angiogenesis, cell proliferation and epithelialization, and formed thicker and more highly organized collagen fiber deposition in full-thickness excisional wound of diabetic rats. The effects of topically applied PDGF-BB were dose-dependent. CONCLUSIONS: PDGF-BB is an important future clinical tool, particularly for stimulating soft tissue repair in patients with an impaired capacity for wound healing.     

骼动脉支架结合股深动脉成形术治疗高危重症下肢缺血的临床研究

目的探讨术中髂动脉支架植入结合股深动脉成形术治疗高危重症下肢缺血的初步临床经验.方法1999年7月至2001年5月,采用术中髂动脉球囊扩张和支架植入结合股深动脉成形术治疗高危重症多节段动脉硬化闭塞症9例(13条肢体),其中男性7例,女性2例,平均年龄76岁,均以静息痛为主诉.术前踝肱指数为0.22±0.17.结果髂动脉球囊扩张和支架植入10条,股深动脉成形11条,股-股动脉人工血管转流术3条,均获得成功.无重要脏器并发症和手术死亡.术后踝肱指数0.41±0.15,与术前相比有提高(P＜0.05).平均随访11个月(1-23个月),患者症状较术前明显改善,均无静息痛,仅3例残余有轻度间歇性跛行.结论髂动脉球囊扩张和支架植入结合股深动脉成形术是治疗高危重症多节段动脉硬化闭塞症的安全、有效方法     

胃减容术3种机械通气对患者氧合情况的比较

目的：探讨病态肥胖患者行腹腔镜胃减容术时，3种机械通气参数对患者氧合情况的影响。方法：选择行腹腔镜胃减容术的病态肥胖24例，按手术时间顺序分为3组，每组8例。A组：潮气量12ml／kg，呼吸频率10次／min；B组：潮气量20ml／kg，呼吸频率10次／min；C组：潮气量12ml／kg，呼吸频率20次／min。分别于气腹前（T1）、气腹后（T2）抽取动脉血测量pH、PO2、PCO2、Plat（平台压）、Peak（峰压）、AaDO2（肺泡-动脉氧分压差）。结果：气腹后B组Plat（33．2±1．8）cmH2O、Peak（36．3±1．6）cmH2O显著高于A组Plat（29．5±3．9）cmH2O（q=3．053，P〈0．05）、Peak（33．0±2．9）cmH2O（q：2．823，P〈0．05）和C组Plat（28．0±4，1）cmH2O（q：4．290，P〈0．05）、Peak（31．8±2．8）cmH2O（q：4．704，P〈0．05）。其他观察指标无统计学差异。结论：病态肥胖患者在腹腔镜下施行胃减容术时，加大潮气量20ml／kg或加快呼吸频率20次／min不能改善患者的氧合情况。     

三种麻醉方法对腹腔镜手术二氧化碳气腹期间自主神经活动趋势的影响

目的以心率变异性（heart rate variability，HRV）为观察指标，观察分析不同的麻醉方法对腹腔镜胆囊切除手术（Laparoscopic cholecystectomy，LC）二氧化碳（CO2）气腹期间自主神经活动趋势的影响。方法选择ASAⅠ～Ⅱ级的择期L患者45例，按手术日期分为全身麻醉组（Ⅰ组，对照组）、全身麻醉＋艾司洛尔组（Ⅱ组）和全麻复合硬膜外阻滞组（Ⅲ组），分别在麻醉前，气腹前，气腹后5、10、20及30min观察HRV及血流动力学的变化。结果与气腹前相比，Ⅰ组低频（LF）、低频／高频（LF／HF）在气腹后不同时点均显著升高（P〈0．05）；Ⅱ组LF／HF在气腹后5、10min显著升高（P〈0．05）；Ⅲ组气腹后各时点LF、HF、LF／HF均无显著变化（P〉0．05）。组间比较，Ⅰ组LF、LF／HF在气腹后各时点均显著高于Ⅱ、Ⅲ组（P〈0．05），Ⅱ组LF在气腹后10min显著高于Ⅲ组（P〈0．05），LF／HF在气腹后5、10min显著高于Ⅲ组（P〈0．05）。HF各组间差异无显著性（P〉0．05）。结论艾司洛尔可减轻气腹引起的应激反应，但不能完全阻止其交感活性的增强；全麻复合硬膜外阻滞用于腹腔镜胆囊切除手术，可以抑制气腹引起的交感神经兴奋，维持自主神经的稳定性。     

探讨Stanford B型主动脉夹层远端破口的分布特点及临床分型

目的 探讨Stanford B型主动脉夹层远端破口的分布特点及其临床分型方法.方法 对新疆维吾尔自治区人民医院2010年1月-2013年6月收治的Stanford B型主动脉夹层患者的计算机断层血管造影资料进行回顾分析,观察其远端破口的分布位置并统计远端破口的数量,进而总结远端破口的分布特点并进一步提出远端破口的临床分型方法.结果 共查阅115例Stanford B型主动脉夹层患者的计算机断层血管造影资料,其中有101例合并有远端破口(87.83％),共计有240个远端破口,平均2.37个/例.结论 Stanford B型主动脉夹层远端破口好发于累及内脏动脉区域,提出Stanford B型主动脉夹层远端破口的分型方法,即:Ⅰ型:内脏动脉以上破口;Ⅱ型:累及内脏动脉的破口;Ⅲ型:肾下腹主动脉破口;Ⅳ型:髂动脉破口.