骨科——脊柱

经后路寰椎椎弓根螺钉系统内固定融合术治疗颈椎疾患；双侧寰椎椎板挂钩及寰枢椎关节间隙螺钉固定术治疗创伤性寰枢椎不稳；两种下颈椎经关节固定技术的静力学比较；前路单枚空心螺钉内固定术治疗齿状突骨折12例临床报道;椎动脉损伤后颈椎前路减压的疗效评价;前后路联合减压植骨带锁钢板内固定治疗复杂颈椎损伤的分析;[编者按]     

创伤性寰枢椎不稳的手术治疗策略

目的探讨创伤性寰枢椎不稳的手术治疗方式,指导选择安全稳定可靠的术式。方法29例创伤性寰枢椎不稳的病例,男22例,女7例;年龄16~52岁,平均32岁。齿状突骨折19例中,Ander-sonⅡ型16例,浅Ⅲ型3例;另外,寰椎横韧带损伤6例,陈旧性寰枢关节旋转性脱位1例,HangmanⅠ型骨折合并齿状突骨折1例,寰椎骨折合并寰椎横韧带损伤1例,齿状突骨折合并单侧枢椎上关节骨折1例。根据不同的损伤部位选择相应的手术方法,其中前路单枚齿状突螺钉固定10例,后路Magerl螺钉固定6例,Magerl联合Gallie5例,Magerl联合Brooks双钛缆固定2例,Magerl联合Apofix椎板夹固定2例,寰枢椎侧块钉板固定4例。19例后路手术中11例采用C1、C2椎板间颗粒状植骨,8例未行植骨融合。结果随访时间6个月~5年,平均18个月。术中未出现椎动脉或脊髓损伤等严重并发症,无内固定断裂。1例术后出现舌下神经麻痹,2周后缓解。10例前路齿状突螺钉固定中9例获得骨性愈合,1例齿状突螺钉固定发生松动,枢椎前方皮质破裂,取出齿状突螺钉,改行后路Magerl Gallie法固定,获得骨性融合。19例后路手术中8例未做融合的病例获骨折愈合,其中6例行内固定取出,基本恢复头颈旋转功能,其余11例均获得骨性融合。结论新鲜齿状突骨折不适于前路齿状突螺钉固定时,后路C1、C2椎弓根钉板暂时固定,可保留寰枢旋转功能。寰枢椎椎弓根钉板系统在生物力学稳定及适应证方面有一定的优势。     

Magerl联合Brooks融合术治疗严重的寰枢椎不稳

目的介绍后路内固定治疗严重寰、枢椎不稳的手术方式。方法12例寰、枢椎不稳患者中单纯II型陈旧性齿状突骨折6例,寰、枢椎前脱位5例(其中习惯性脱位2例,伴齿状突骨折2例,伴横韧带断裂1例),寰、枢椎旋转脱位伴横韧带断裂1例。采用后路C1,2经关节螺钉联合Brooks融合术治疗。结果12例寰、枢椎不稳患者中11例共放置经关节螺钉22枚,1例陈旧性齿状突骨折患者因C2单侧椎板上缘劈裂仅行Brooks融合术。本组患者术中无椎动脉、硬脊膜破裂和脊髓损伤等并发症,随访3~32个月,植骨全部融合。结论Magerl联合Brooks融合术是治疗严重寰、枢椎不稳的有效方法,可提供有效的固定和提高植骨融合率。     

骨科：脊柱

经前路颈椎多节段椎管扩大术的实验研究；颈椎后路经关节螺钉钢板内固定术在下颈椎骨折脱位中的应用；后-前路联合手术治疗下颈椎骨折脱位伴关节突交锁；椎弓根螺钉技术在下颈椎不稳中的安全使用方法；经口咽Ⅱ型前路寰枢椎复位钢板内固定系统在难复性寰枢椎脱位中的应用     

前路三钉内固定治疗寰椎-齿状突Ⅱ型骨折

背景：齿状突加寰枢椎前路经关节螺钉内固定是近来治疗寰椎-齿状突Ⅱ型骨折的一种新方法,临床报道较少。 目的：探讨颈前路三钉,即齿状突螺钉加寰枢椎前路经关节螺钉内固定治疗寰椎-齿状突Ⅱ型骨折的方法及疗效。 方法：2008年2月至2011年10月于C型臂X线机透视下行颈前路齿状突螺钉加寰枢椎经关节螺钉内固定治疗寰椎-齿状突Ⅱ型骨折5例。 结果：5例骨折患者共植入5枚齿状突螺钉,9枚经寰枢关节螺钉,1例因左侧经寰枢关节螺钉进钉点处骨折而行右侧单侧固定。全部获得随访,随访时间为10~30个月,平均18个月,螺钉位置满意,齿状突骨折均获骨性愈合,寰枢关节稳定,无一例发生螺钉松动、断钉,无一例发生脊髓、椎动脉损伤等并发症。 结论：颈前路齿状突螺钉加寰枢椎经关节螺钉内固定治疗寰椎-齿状突Ⅱ型骨折,对齿状突直接固定同时即刻稳定寰枢椎,为寰椎-齿状突Ⅱ型骨折患者提供了一种新的治疗方法。     

颈1-2关节突间隙螺钉固定融合治疗寰枢椎损伤及不稳

目的：探讨应用经C1－2关节突间隙螺钉固定技术治疗寰枢椎病变的可行性及临床疗效。方法：自2000年4月－2002年4月应用后路经C1－2关节突间隙螺钉内固定技术治疗C2双侧椎弓骨折3例，陈旧性齿状突骨折1例，寰枢椎不稳1例，观察术后寰枢椎的稳定性、植骨融合率及颈椎活动度。结果：5例病人术中无神经及血管损伤等并发症，术后即刻获得稳定，经4－20个月随访，均获得骨性愈合，螺钉无松动、退出及断裂，颈椎旋转活动度平均丧失35．72％。结论：经C1－2关节突间隙螺钉固定技术在治疗寰枢椎疾病中是安全有效的，为重建寰枢椎间稳定提供了一种新的内固定方法。     

经关节螺钉内固定治疗寰枢椎不稳

目的 探讨经关节螺钉内固定治疗寰枢椎不稳的疗效.方法 自2000年5月至2011年10月使用经关节螺钉内固定治疗寰枢椎不稳患者56例,男43例,女13例;年龄17 ～71岁,平均38岁.1例患者脊髓神经完全损伤,29例无脊髓神经损伤症状,26例伴有脊髓神经不全损伤,按美国脊髓损伤协会(ASIA)脊髓神经功能障碍分级:C级10例,D级16例;ASIA评分50～90分,平均(78.5±9.3)分.其中后路经关节螺钉内固定32例,在寰椎后弓与枢椎椎板表面植骨.前路经关节螺钉内固定24例,在寰椎前弓下缘和齿状突基底部之间植骨.结果 1例颈脊髓神经完全损伤患者前路经寰枢关节螺钉内固定,术后1个月死于肺部感染.其他55例患者术后获6个月至9年(平均16个月)随访,手术切口均Ⅰ期愈合.1例齿状突Ⅱ型粉碎性骨折并寰枢关节脱位患者寰枢椎前路经关节螺钉内固定并植骨,齿状突未骨性愈合,但寰枢关节纤维连接无不稳定表现.其余植骨患者均获骨性融合.26例脊髓神经不全损伤患者术后ASIA分级(C级3例,D级10例,E级13例)和评分[(92.5±8.6)分]均较术前明显改善,差异有统计学意义(P＜0.05).结论 寰枢椎经关节螺钉内固定,操作简便、费用低廉、疗效可靠,可以作为治疗寰枢椎不稳患者的有效手段.     

后路寰枢椎钩钉棒联合内固定植骨融合术治疗寰枢椎不稳定

目的探讨后路寰枢椎钩钉棒联合内固定植骨融合术治疗寰枢椎不稳的临床疗效。方法采用寰椎椎板钩联合枢椎椎弓根钉内固定植骨融合术治疗8例齿状突骨折及寰枢椎脱位。结果 7例获得随访,均获得骨性愈合,神经功能D级2例,均恢复至E级。颈椎活动无明显疼痛,动度良好5例,可2例。结论后路寰枢椎钩钉棒联合内固定植骨融合术治疗效果好,值得临床推广应用。     

齿状突骨折并寰枢椎脱位的手术治疗

目的评价几种手术方法治疗齿状突骨折合并寰枢椎脱位的临床应用效果。方法回顾性分析了采用手术治疗的24例齿状突骨折合并寰枢椎脱位的病例,其中齿状突Ⅱ型10例,Ⅲ型14例,采用前路齿状突加压螺钉内固定8例;椎板间ATLAS钛缆系统固定或Apofix椎板夹固定、后路寰枢椎融合10例;改良后路Magerl联合Gallie内固定、寰枢椎融合6例。结果术后随访3～30个月,颈椎活动度的保持以齿状突螺钉固定最佳,后路椎板间固定和Magerl联合Gallie内固定病例颈椎旋转度丧失较多;7例出现不完全性四肢瘫患者的术前脊髓功能Frankel分级C级4例、D级3例,术后D级5例、E级2例,无一例发生脊髓损伤加重及术后感染;术后3个月X线片显示所有内置物无松动、脱落及断裂,无复位丢失。结论前路齿状突螺钉技术是治疗齿状突骨折合并寰枢椎脱位的首选,只有在齿状突螺钉禁忌时才考虑采用寰枢椎融合;坚强内固定是后路寰枢椎融合的有力保障,改良Magerl联合Gallie三点内固定具有较好的生物力学性能,是实施后路寰枢椎融合的理想内固定技术。     

后路寰枢椎经关节螺钉内固定治疗陈旧性齿状突骨折

[目的]对后路寰枢椎经关节螺钉内固定治疗陈旧性齿状突骨折进行回顾总结。[方法]33例陈旧性齿状突骨折经Anderson-D＇Alonzo分类Ⅱ型31例，Ⅲ型2例，无Ⅰ型病例。所有患者行后路寰枢椎经关节螺钉内固定植骨融合术，其中9例同时行Gallie法内固定。[结果]术后进行颈椎正侧位片随访6～52个月（平均7．9个月），32例获牢固骨性愈合，融合率97％。[结论]后路寰枢椎经关节螺钉内固定是治疗陈旧性齿状突骨折简单有效的方法。     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.