椎体成形术对胸腰椎爆裂型骨折的治疗意义

目的：探讨腰腰椎爆裂型骨折撑开复位与椎体成形术后椎体结构和生物力学性能的变化。方法：收集6具新鲜成人尸体的胸腰椎标本，制成T11－L1、L2－L4、T12－L2节段标本共10具，用自由落体撞击试验造成中间椎体爆裂型骨折，撑开复位、用注射型自固定磷酸钙人工骨行椎体成形术。分别于骨折前、骨折撑开复位后、椎体成形术后用薄层CT扫描测量中间椎体内空隙，用双能X线骨密度仪测定骨密度，用万能材料试验机测定骨折前、椎体成形术后中间椎体与其上方椎间盘在前屈、后伸、侧屈和扭转就压力 下刚度的变化，并比较成形术后的伤椎及其下方的完整椎体的抗极限压缩测试结果。结果：8具标本造中间椎体爆裂型骨折模型成功。（1）骨折前椎体内无明显空隙；骨折并撑开复位后椎体内空隙体积平均为5．25cm^3，占椎体总体积的13．9％；椎体成形术后空隙减少，与骨折前相比差异无显著性意义。（2）骨折前椎体骨密度在正常范围，骨折并撑开复位后骨密度较骨折前降低；椎体成形术后，骨密度较骨折复位后及骨折前均明显升高。（3）椎体成形术后，伤椎的刚度与骨折前相比差异无显著性意义，抗极限压缩强度的均值低于其下方完整椎体，但差异无显著性意义；伤椎上方椎间盘在前屈和后伸应力下的刚度小于骨折前，但在侧屈应力下差异无显著性意义；标本在扭转应力下的刚度小于骨折前。结论：（1）撑开复位未能恢复胸腰椎爆裂型骨折椎体结构上的完整性，这可能是后路切开复位内固定术后发生内固定失败与矫正度丢失的重要原因。（2）应用注射型自固化磷酸钙人工骨行椎体成形术有助于伤椎的重建，术后脊柱的生物力学特性接近骨折前水平。     

椎弓根钉内固定联合椎体成形术治疗骨质疏松性胸腰椎爆裂骨折的三维有限元研究

目的 采用有限元方法比较骨质疏松性胸腰椎爆裂骨折在椎弓根钉内固定联合椎体成形术与椎弓根钉结合伤椎置钉内固定术后的生物力学稳定性.方法 建立骨质疏松性L1椎体爆裂骨折有限元模型,模拟短节段椎弓根钉联合椎体成形术(A组)以及椎弓根钉结合伤椎置钉内固定术(B组),比较2组前屈、后伸、侧屈、旋转载荷下L1椎体最大位移及内固定物...     

后路胸腰椎单椎爆裂骨折经伤椎内固定的治疗

目的探讨胸腰椎单椎爆裂骨折经后路临椎椎弓根内固定连同伤椎椎弓根内固定的手术疗效。方法2009年1月至2011年12月,笔者收治36例胸腰椎单椎爆裂骨折经后路椎弓根临椎加伤椎内固定顶压撑开复位。结果36例患者均获得随访,术后后凸畸形纠正、伤椎椎体复位满意。远期伤椎椎体高度丢失不明显。获得良好结果。结论经伤椎短节段椎弓根内固定治疗胸腰椎单椎体爆裂骨折不失为基层医院首选的方法。     

后路椎弓根器械治疗胸腰椎骨折脱位

目的研究短节段椎弓根器械复位固定治疗胸腰椎骨折脱位的方法和疗效。方法应用短节段椎弓根器械复位固定治疗胸腰椎骨折脱位66例,41例行横突间或椎板间植骨融合,9例经伤椎椎弓根行可吸收球囊椎体成形术,平均随访14个月。结果短节段椎弓根器械(Dick除外)复位固定治疗胸腰椎骨折脱位,伤椎术后椎体高度比和Cobbs角有显著改善,41例后路植骨融合和9例椎体成形术患者无断钉、钉松动或矫正度丢失现象。结论短节段椎弓根器械复位固定,结合后路植骨融合或椎体成形术是治疗胸腰椎骨折脱位的良好方法。     

短节段椎弓根螺钉固定复位结合骨水泥伤椎强化治疗老年人胸腰椎爆裂骨折

目的 探讨后路切开短节段椎弓根螺钉固定复位结合骨水泥伤椎强化治疗老年人胸腰椎爆裂骨折的临床疗效. 方法 15例老年人胸腰椎爆裂骨折,年龄63～76岁(平均67.2岁),采取后路切开短节段椎弓根螺钉固定复位结合骨水泥伤椎成形术. 结果 本组手术持续时间1.0～2.1小时,平均1.5小时,术中出血量50～150ml,平均80ml,术中C型臂X线机透视未见骨水泥渗漏.术后2周切口愈合拆线后离床负重行走,15例患者均顺利出院.3个月后腰背疼痛VAS评分平均减少5分,术后X线摄片显示后凸 Cobb角平均矫正17.6°,丢失的椎体高度恢复92％以上.随访18个月后显示Cobb角平均只丢失4.2°,椎体高度平均改变＜2.2％,腰椎过伸过屈动力摄片显示固定段无异常活动,未发现有椎弓根螺钉松动、断裂病例. 结论 后路切开短节段椎弓根螺钉复位固定治疗老年人胸腰椎爆裂骨折,能有效恢复脊柱序列,而骨水泥伤椎强化使老年人胸腰椎爆裂骨折得到即刻稳定重建,有利于术后早期离床负重行走,减少术后长期卧床所致并发症的发生.     

椎弓根钉固定结合椎体成形术治疗胸腰椎爆裂骨折的现状与展望

胸腰椎爆裂骨折是脊柱外科的常见疾患．占脊柱外伤的10％～20％。短节段椎弓根钉内固定（short-segment pedicle instrumentation，SSPI）是治疗胸腰椎爆裂骨折的主要手术方式之一，但存在较高的内固定失败率。利用SSPI复位固定后实施椎体成形术是近年来治疗胸腰椎爆裂骨折的新进展。一些椎体成形术用于治疗胸腰椎爆裂骨折后显示出良好的近期疗效。现就椎体成形术与SSPI相结合治疗胸腰椎爆裂骨折的理论基础及临床应用作一综述。     

体位复位在椎体后凸成形术中的应用效果

目的 探讨椎体后凸成形术中,球囊撑开复位结合躯体过伸复位对骨质疏松性椎体骨折的治疗效果.方法 对51例78椎骨质疏松性椎体压缩性骨折患者采用随机双盲法分为对照组和实验组,对照组予以单球囊双侧椎弓根入路椎体后凸成形术;实验组在术前予以极度后伸位复位后进行单球囊双侧椎弓根入路椎体后凸成形术.收集两组术前和术后的伤椎高度,C...     

经伤椎椎弓根固定治疗胸腰椎爆裂骨折

目的探讨经伤椎椎弓根固定治疗胸腰椎爆裂骨折的可行性和疗效。方法采用经伤椎椎弓根固定治疗胸腰椎爆裂骨折26例。结果本组随访6～18个月,术后椎体高度、Cobb角对比术前明显改善。结论经伤椎椎弓根固定治疗胸腰椎爆裂骨折是可行的,不仅使伤椎复位满意,矫正后凸畸形,而且可减少内固定松动、断裂,是治疗胸腰椎爆裂骨折的有效方法。     

椎体骨折椎弓根钉固定及椎体成形临床研究

目的探讨经椎弓根植骨和椎体成形术治疗胸腰椎爆裂骨折的方法和效果。方法采用经椎弓根植骨椎体成形术治疗胸腰椎爆裂骨折15例,伤后4h~7d椎弓根螺钉系统固定复位,同时用自制植骨椎注器经椎弓根椎体内植骨结合中后路植骨治疗。结果15例患者手术均获成功,术后无神经症状加重或出现新的神经症状,无出现异物反应者。随诊9~14个月,平均6个月,随访期间无内固定松动及断裂现象,伤椎高度及脊柱生理弧度无丢失。3例有轻度腰背痛,其余无腰背痛。结论经椎弓根椎体植骨成形术重建了椎体高度,增加了脊柱前柱的抗压稳定性,使病人能早期活动,减少内固定物因应力过大造成的断钉、松动、椎体再压缩等并发症。     

后路不同复位方式治疗胸腰椎爆裂骨折的对比研究

目的对比观察不同后路复位方式治疗胸腰椎爆裂骨折术后患者伤椎前缘压缩比、侧位Cobb角、椎管面积比影响。方法回顾性分析72例胸腰椎爆裂骨折后路手术治疗患者资料,根据复位方式不同分为观察组（经伤椎单节段椎弓根螺钉系统内固定）38例,对照组（跨伤椎椎弓根椎弓根螺钉系统内固定）34例,比较治疗方法及术后疗效情况。结果观察组在手术时间、切口长度、术中出血等方面均低于对照组。组内比较,观察组及对照组术前及术后1周在伤椎前缘压缩比、侧位Cobb角及椎管面积比改善均有显著统计学意义（P〈0．01）,组间比较,术后1周两组各指标无统计学差异（P〉0．05）,末次复查见观察组在椎体前缘高度及侧位Cobb角丢失情况轻于对照组,在术后并发症发生率差异有统计学意义。结论经伤椎单节段椎弓根螺钉系统内固定较跨伤椎椎弓根螺钉系统内固定治疗胸腰椎爆裂骨折能够在确保脊柱稳定性、椎体高度恢复的基础上,减少相邻的节段椎体发生退变,减少了术后的矫正度丢失,防止脊椎不稳的发生,减少运动节段丢失。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.