3种椎弓根内固定器械的临床应用

目的　比较3种椎弓根内固定器械治疗胸腰椎骨折、腰椎滑脱的临床效果。方法　回顾分析采用Steffee、Dick、及SF内固定器械治疗的胸腰椎骨折、腰椎滑脱共计2 4 7例临床资料,对其中获得随访的2 2 1例术后效果、并发症及治疗前后X- ray改善情况作比较分析。结果　a) Steffee、Dick、SF3种椎弓根内固定器械治疗后神经功能改善率分别为6 0 .1% ,76 .1% ,90 .7% ;脊柱活动改善率分别为74 .4 % ,81.0 % ,92 .0 % ;腰背痛改善率分别为80 .5 % ,84 .1% ,92 .0 % ;下肢疼痛改善率分别为85 .4 % ,87.3% ,88.2 %。b)该3种治疗方法的定位错误率分别为4 .8% ,4 .7% ,2 .6 % ;螺丝钉断裂率分别为9.7% ,6 .3% ,3.9% ;螺钉及钉棒连接松动率分别为8.5 % ,7.9% ,3.9% ;一过性神经根性体征分别为9.7% ,4 .7% ,2 .6 %。c)骨折治疗组椎体高度矫正率分别为6 4 .5 % ,86 .0 % ,94 .7% ;融合节段Cobb′s角均值分别为2 1.5°,18.4°,6 .9°;滑脱组位移矫正率分别为84 .3% ,85 .4 % ,89.6 %。结论　a) SF内固定器在治疗胸腰椎骨折及腰椎滑脱的临床应用中效果优于Dick及Steffee。b)术中并发症的发生与掌握椎弓根内固定技术的熟练程度有关。     

退变性腰椎滑脱症的临床治疗

目的探讨退变性腰椎滑脱的治疗方法.方法经后路减压、椎弓根螺钉系统内固定、植骨融合术治疗退变性腰椎滑脱25例.结果术后19例滑脱完全复位,6例滑脱无明显复位但患者症状有明显改善.25例经6～24个月随访,治疗改善率为86.9%,无椎弓根钉断裂及滑脱加重.结论该方法效果满意,术中重点在减压,关键是为融合创造条件.     

椎弓根固定系统对脊柱稳定性的疗效评价

目的：探讨椎弓根固定系统对脊柱稳定性的影响。方法：对胸腰椎不稳定性骨折80例及腰椎滑脱12例分别采用Dick钉。AF钉，Steffee钢板，C-D棒系统，TSRH系统固定。术后定期随访观察。并通过X线平片测量椎体高度及复位情况。结果：脊柱骨折组椎体或椎间隙高度完全恢复64例。占80%，未完全恢复16例，占20%。神经功能恢复优良率85%。腰椎滑脱组复位率95%。融合率为80.5%。优良率90%。结论：选择椎弓根固定系统治疗外伤性脊柱不稳定性骨折及腰椎滑脱疗效确切。结果令人满意。     

四种经椎弓根内固定器治疗胸腰椎骨折及腰椎滑脱的体会（附29例报告）

采用Dick,Steffee,RF及S－F四种经椎弓根内固定复位器治疗29例胸腰椎骨折及腰椎滑脱患者,经12－24个月随访,所有脊柱骨折及腰椎滑脱均有明显的复位,根性疼痛缓解,4例合并脊髓圆员伤者在术后1－12个月恢复,2例合并截瘫者系Frankel A级病例,尽管复位固定情况良好,但恢复状况不良,2例因Dick锁夹松动致部分矫正角丢失,Steffee螺钉断裂2例,无感染及神经根损伤等并发症,Dick,Steffee,RF及S－F虽均为经椎弓根内固定器,但其结构和操作繁简不同,适应证及疗效亦有差别,选择操作简单安全,复位效果满意,固定坚强可靠的器械,有助于提高手术质量及疗效。     

腰椎后路经椎弓根动态固定系统研究新进展

腰椎融合术是治疗腰椎间盘源性疼痛、节段性不稳、退变性滑脱等疾患的主要手段,虽然内固定的应用使融合率增加和临床效果改善,但临床满意率低于融合率,还存在融合相邻节段退变加速等并发症[1、2]。后路经椎弓根腰椎动态固定技术符合脊柱生理性稳定,限制脊柱过度活动的     

椎管减压、内固定联合Cage椎间融合与横突间植骨融合治疗退行性腰椎滑脱的比较

目的 比较腰椎管减压、椎弓根内固定联合后路Cage椎间融合与横突间植骨融合治疗退变性腰椎滑脱合并腰椎管狭窄的早期临床疗效。方法 分别采用椎管减压、椎弓根内固定联合后路Cage椎间融合与横突间植骨融合治疗经严格保守治疗无效的退行性腰椎滑脱患者31例和19例。比较术后临床症状改善和滑脱复位情况。结果 随访时两组患者腰骶部疼痛改善率分别为80％和84．2％，间歇性跛行改善率分别为88．46％和85．7％。I度滑脱完全复位分别为26例和14例，Ⅱ度滑脱完全复位分别为3例和2例，总复位率分别为93．5％和84．2％。所有病例椎间高度恢复正常或接近正常，Cage位置良好，无脱出，未见下沉。椎弓根内固定器无脱出、弯曲和断裂。结论 椎间融合与横突间植骨融合治疗退行性腰椎滑脱都能达到满意复位，可以充分减压，重建脊柱生理序列和稳定性，在复位率、症状改善率、手术后并发症方面均无显著性差异，临床效果满意。     

DRFS椎弓根系统治疗重度腰椎滑脱症

目的总结DRFS椎弓根系统治疗重度腰椎滑脱症的临床疗效。方法自1999年11月至2006年8月，32例重度腰椎滑脱症的病人采用DRFS椎弓根系统进行手术治疗，其中Ⅱ度滑脱23例，Ⅲ度滑脱9例。结果所有病人术后随访均超过12个月，平均36个月。腰椎滑脱平均复位率94％，临床疗效评价优18例，良10例，可4例，优良率达87．5％。结论DRFS内固定系统有纵向撑开及滑脱椎体提拉复位的作用，具有设计合理、操作简便、固定可靠、复位好、脊柱融合率高、效果满意的优点。     

椎弓根固定系统对脊柱稳定性的疗效评价

目的探讨椎弓根固定系统对脊柱稳定性的影响.方法对胸腰椎不稳定性骨折80例及腰椎滑脱12例分别采用Diek钉、AF钉、Steffee钢板、C-D棒系统、TSRH系统固定.术后定期随访观察,并通过X线平片测量椎体高度及复位情况.结果脊柱骨折组椎体或椎间隙高度完全恢复64例,占80%,未完全恢复16例,占20%.神经功能恢复优良率85%.腰椎滑脱组复位率95%,融合率为80.5%,优良率90%.结论选择椎弓根固定系统治疗外伤性脊柱不稳定性骨折及腰椎滑脱疗效确切,结果令人满意.     

PLIF加椎弓根内固定治疗腰椎滑脱症

目的探讨后路腰椎间植骨融合加椎弓根螺钉复位内固定治疗腰椎滑脱的临床应用。方法自2004年11月至2008年3月对31例腰椎滑脱采用后路腰椎间融合加椎弓根螺钉复位内固定治疗,分析手术疗效、滑脱椎体复位率及椎体间植骨融合率。结果后路腰椎间融合加椎弓根螺钉内固定确切,复位率为96.8%,椎体间植骨融合率为96.8%,椎间隙高度维持良好,滑脱椎体复位无丢失,总体疗效优良率为90.3%。结论腰椎间融合加椎弓根螺钉复位内固定治疗腰椎滑脱症具有复位满意、固定牢靠、植骨融合率高、减压彻底、临床疗效满意等优点。     

椎体间蜗柱骨水泥充填结合椎弓根钉内固定治疗腰椎滑脱症

目的　应用椎间蜗柱骨水泥充填、RF、Steffee椎弓根钉内固定治疗腰椎滑脱症。方法　对 12例腰椎滑脱经后路采用研制的椎间撑提复位器械对滑脱椎体进行撑提复位后 ,椎间蜗钻水平攻槽 ,骨水泥充填固定 ,椎弓峡部植骨 ,滑移椎行RF或Steffee钢板内固定。结果　本组 12例 14个间隙 ,Ⅰ度滑脱 7例 9个间隙 ,Ⅱ度以上 5例。经 7～ 4 2个月随访 ,平均 2 6个月。优 9例 (75 % ) ,良 2例 (16 7% ) ,可 1例 (8 3% )。结论　应用蜗柱骨水泥椎间支撑 ,RF、Steeff椎弓根系统内固定、椎弓峡部植骨治疗腰椎滑脱症 ,能够增加椎间高度、恢复椎管和椎间孔容积 ,延缓小关节退变 ,既能使马尾及神经根得到有效减压 ,又可使滑移的椎体得到牢固的椎间固定 ,获得良好的治疗效果。     

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 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.     

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.     

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.     

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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.