AF椎弓根钉棒内固定系统治疗不稳定性胸腰段骨折(附26例病例报告)

[目的]观察AF椎弓根钉棒内固定系统治疗不稳定性胸腰段骨折合并截瘫的疗效。[方法]自1998年10月～2004年10月采用AF椎弓根螺钉系统内固定结合推移复位法治疗不稳定性胸腰段骨折合并截瘫的患者26例。[结果]Cobb's角由术前平均24.1°矫正到术后平均2.5°。椎体前、后缘高度由术前40%和68%恢复到术后的91%与98%,三者均有显著统计学差异(P<0.01)。术后平均随访13.5个月,26例不完全性截瘫患者均有1～3级恢复,6例全截瘫患者中,有2例1～2级恢复。[结论]推移复位法配合AF椎弓根钉棒内固定系统治疗胸腰段不稳定骨折,可达到良好复位和恢复椎管原有容积的效果。     

椎弓根螺钉治疗胸腰椎爆裂性骨折

目的探讨椎弓根螺钉在胸腰椎爆裂性骨折治疗中的疗效。方法回顾性分析2002年以来应用椎弓根螺钉的治疗45例胸腰椎骨折患者资料。全部患者采用后路椎管减压,椎体植骨加椎弓根螺钉内固定治疗。结果全部病例得到随访,平均20个月(6～60个月),其中18例脊髓不全损伤患者Frankel分级提高l～3级(平均2级)。A级10例有2例恢复到B级,1例恢复到C级,其余患者部分术后感觉平面下降或下肢感觉部分恢复,运动功能无明显改善。术后遗留轻度腰背痛3例,1例螺钉松动,无一例发生感染。随访病例均行X线片检查,后凸角由术前平均25°(11°～35°)矫正到术后10°(0°～15°),椎体前缘高度矢状径指数术前30°(15°～55°),恢复到术后85°(72°～100°)。结论后路椎管减压,椎体植骨加椎弓根螺钉内固定治疗胸腰椎爆裂性骨折是一种较理想的手术方法。此方法操作简单、安全,在解除神经及硬膜囊压迫的同时扩大了椎管,杜绝了继发性椎管狭窄,增加了脊柱稳定性,值得推广。     

AF内固定治疗胸腰段骨折近期疗效评价

目的 评价AF椎弓根螺钉内固定系统治疗胸腰段骨折的近期疗效。方法 我科自2004年7月至2005年7月间采用AF椎弓根螺钉内固定系统治疗胸腰段骨折32例。部分患者行椎管减压，横突间植骨融合。结果经术后9～13个月的随访，与术前比较，术后及末次随访时的Cobb’s角及椎体前、后缘高度均明显恢复（P〈0．01）。本组患者脊髓损伤分级评判，除1例完全性瘫痪患者术后无功能恢复外，其余患者均获得了不同程度的功能恢复。结论 AF椎弓根内固定系统治疗胸腰段骨折，固定牢靠，椎体高度再丢失少。间接复位能使突入椎管腔内的伤椎椎体后壁精确复位，使椎管有效减压。     

胸腰椎骨折椎弓根内固定的临床体验

目的：评价椎弓根螺钉内固定系统治疗胸腰段骨折合的疗效。方法：1998年5月至2006年5月，采用椎弓根螺钉内固定治疗不稳定性胸腰段骨折合71例。结果：椎体高度由术前46％恢复到术后的97．3％。二者均有显著统计学差异（P〈0．01）。术后随访6-38个月，平均随访19个月，瘫患者中有1-2级恢复，无远期疼痛。结论：椎弓根内固定系统能使胸腰段骨伤椎椎体复位，牢靠固定，并使椎管有效减压。     

经后路椎管骨块推入复位加椎弓根钉固定治疗胸腰段单椎体爆裂骨折

目的探讨应用后路椎管骨块推入复位加椎弓根钉固定治疗胸腰段单椎体爆裂骨折的疗效。方法对17例胸腰段单椎体爆裂骨折,采用后路打开椎管应用"L"形椎体骨块推入器将凸入椎管内的骨块推回爆裂的椎体使其复位,恢复或基本恢复椎管的矢状径,解除骨块对脊髓或神经根的压迫,同时采用椎弓根脊柱撑开固定加椎板或横突植骨术的治疗。结果术后椎管矢状径平均复原92.4%,截瘫指数有1~3分改善,伤椎高度平均恢复至原高度的81.47%。结论后路推入复位加椎弓根钉固定治疗胸腰段单椎体爆裂骨折的方法,能够较好复位凸入椎管内的骨块,有效的解除椎管的骨性压迫,恢复椎体高度和椎管矢状径,损伤小,疗效满意。     

RF-Ⅲ(AF)脊柱复位固定器手术治疗胸腰椎骨折22例报告

目的探讨AF脊柱复位固定器在胸腰椎骨折治疗中的使用价值。方法用RF-Ⅲ(AF)脊柱复位固定器手术治疗胸腰椎压缩性骨折无椎管压迫者7例;爆裂性骨折椎管压迫12例,chance骨折2例,骨折伴脱位1例;前者仅做AF复位固定韧带修补术,后者增用椎板减压骨块复位椎体外植骨融合。结果术后随访3~20个月。X线片示椎体高度完全恢复17例,恢复90%以上4例,无明显恢复1例。Cobb角由术前平均29(°12°~41)°矫正到术后平均约4(°0°~9)°;8例椎管压迫明显者术后CT复查椎管容积明显增大。Frankel分类A级病人感觉平面下降或部分恢复,运动,排便功能无改善;B-D级病人均有1~2级恢复。断棒1例,螺钉松动2例。椎体前缘高度丢失3例;Cobb角增加5°-8°。结论RF-Ⅲ(AF)系统脊柱复位固定器在脊柱纵轴上有撑开,压缩(前柱撑开)性能,是一种较理想的脊柱三维复位固定器材。     

AF椎弓根钉系统治疗胸腰椎爆裂性骨折46例

目的探讨AF椎弓根钉内固定系统治疗胸腰椎爆裂性骨折的疗效。方法应用AF经椎弓根钉内固定系统治疗胸腰椎爆裂性骨折46例。结果平均随访11个月。46例椎体前缘高度由术前平均25％恢复至平均95％。椎管内移位骨块复位率达90％。神经损伤的恢复按ASIA分级：A级中19例无变化，余27例均提高1～2级。结论AF椎弓根钉内固定系统能达到满意复位固定及椎管有效减压，是一种治疗胸腰椎爆裂性骨折理想的方法。     

AF内固定系统治疗脊柱胸腰段骨折96例分析

[目的]探讨AF内固定系统在胸腰椎骨折中的应用.[方法]对96例经影像学诊断的胸腰段骨折病人,给予AF系统固定或同时行椎板减压、植骨融合.[结果]术后随访6～24个月,X线片显示骨折椎体高度完全恢复者36例,＞90%31例,＞80%29例.Cobb角由术前的平均27.5°(10°～41°),矫正到术后约4°(0°～10°).术后CT复查椎管容积明显扩大.Frankel分类A级17例病人感觉平面下降或部分恢复,运动功能无明显恢复,B-D级病人均有1～2级的恢复.32例随访时X线片与术后即时复查的X线片比较,有椎体前缘高度丢失,Cobb角增加4～12°.[结论]AF内固定系统是胸腰段骨折内固定的良好选择,但也有其本身的不足,要严格掌握适应证,准确操作.     

膨胀与普通椎弓根钉治疗脊柱胸腰段骨折合并骨质疏松的对比研究

目的比较膨胀椎弓根螺钉系统与普通椎弓根螺钉系统在治疗合并骨质疏松的脊柱胸腰段骨折中的临床疗效,特别是二者在恢复及维持胸腰椎高度、生理曲度方面的应用效果.方法我院自2002年2月至2004年2月临床诊断为脊柱胸腰段骨折合并骨质疏松,经后路行复位、椎弓根系统内固定病例获随访48例,其中应用膨胀椎弓根螺钉系统治疗22例(A组),应用普通椎弓根螺钉系统治疗26例(B组),观察复位、固定及骨折愈合情况,测量术前及术后随访的椎体前缘压缩率、矢状面后凸Cobb角.结果全部48例患者经平均15.2个月(12～20个月)随访,骨折均愈合,未发现内植物并发症.平均愈合时间A组(2.8±0.8)月,B组(3.0±1.1)月,差异无显著性(P＞0.05).A组术前椎体前缘压缩率、后凸Cobb角均值分别为(47.1±11.6)%、(23.2±5.1)°;术后随访矫正为(93.6±5.7)%、(5.2±2.7)°;B组术前椎体前缘压缩率、后凸Cobb角均值分别为(45.8±12.1)%、(22.5±6.7)°;术后随访矫正为(80.2±8.3)%、(8.6±2.9)°.各组内术前与术后随访的椎体前缘压缩率、Cobb角差异均显著(P＜0.05).A、B组间术前的椎体前缘压缩率、Cobb角差异均无显著性(P＞0.05);A、B组间术后随访的椎体前缘压缩率、Cobb角差异均有显著性(P＜0.05).结论对于脊柱胸腰段骨折合并骨质疏松病例,采用膨胀椎弓根螺钉内固定系统在恢复、维持胸腰椎高度及生理曲度方面优于普通椎弓根螺钉系统,但二者在骨折愈合时间方面差异无显著性.     

SF椎弓根内固定器治疗胸腰段骨折

目的　评价SF椎弓根内固定器治疗胸腰段骨折的效果。方法　应用SF手术治疗 4 3例胸腰段不稳定骨折 ,其中探查椎管 2 5例。结果　骨折接近解剖复位 ,椎管得到有效减压。神经功能(Frankel分极 )提高 1～ 2级 32例 ,提高 3级 1例。椎体前缘高度平均提高 4 0 % ,Cobb角平均纠正2 2 5°。结论　SF内固定能恢复脊柱生理弧度和椎体高度 ,利于神经功能的恢复 ,是治疗胸腰椎骨折有效的方法之一。     

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.     

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.     

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.