寰枢椎脱位的外科治疗原则

寰枢椎脱位（atlanto-axial dislocation）常累及延髓生命中枢与椎-基底动脉,导致严重残疾,甚至威胁生命。寰枢椎是颈椎中活动度最大的节段,其旋转活动占整个颈椎旋转活动度（120°~160°）的50%以上。因此,合理的寰枢椎脱位外科分型和治疗原则对其治疗的效果、安全性和颈椎功能的保留具有重要意义。自从Zileli等[1]2002年报道前后路联合手术治疗难复性寰枢椎脱位以来,其基础和临床研究进步很快,例如：前路经口腔寰枢椎病灶清除、螺钉钢板复位内固定术[2],经口腔或内窥镜下行寰枢椎前方软组织松解、后方寰枢椎椎弓根螺钉复位固定术[3],以及各类后路钉板和钉棒内固定系统[4~6]等技术已在国内广泛开展。但随着寰枢椎脱位外科治疗的报道增多,需要再次手术翻修病例也有上升的趋势,应该引起临床高度重视。在此,笔者针对寰枢椎脱位的外科治疗原则,谈谈自己的管见,与同道商榷。     

浅谈寰枢椎脱位的治疗选择与手术适应证

寰枢椎脱位(atlanto-axial dislocation)是指创伤、先天畸形、退变、肿瘤、炎症或手术等因素造成的寰枢椎骨关节面失去正常对合关系而发生关节功能和/或神经功能障碍。由于寰枢椎的解剖结构复杂,周围有许多重要神经和血管,故该部位的手术治疗难度大,风险高,是外科手术的“危险区”。此外,寰枢椎是颈椎中活动度最大的节段,其旋转活动约占整个颈椎旋转活动度(120°￣160°)的50%以上。因此,寰枢椎脱位的手术适应证和术式选择原则对其治疗的安全性和颈椎功能的保留具有重要意义。近十年来,寰枢椎脱位的基础和临床研究进步很快,例如:前路经口腔…     

寰枢椎脱位外科治疗的现状与思考

 寰枢椎脱位（atlantoaxial dislocation）是上颈椎创伤和疾病的病理转归结果,主要特点是寰枢椎侧块关节面失去正常对合关系和延髓压迫,导致严重残疾,甚至威胁生命。由于寰枢椎比邻延髓生命中枢,在2000年以前,临床对寰枢椎脱位缺乏有效的手术治疗方法,国内外骨科和神经外科领域一直将上颈椎称为手术的“禁区”或“危险区”,严重寰枢椎脱位造成延髓生命中枢损伤的死亡率高达44%~71%^[1]。寰枢椎是颈椎中活动度最大的节段,其旋转活动占整个颈椎旋转活动（120°~160°）的50％以上。因此,合理的寰枢椎脱位外科分型和治疗原则对其治疗的效果、安全性和颈椎功能的保留具有重要意义。     

寰枢椎脱位三维非线性有限元模型的建立和分析

目的:探索寰枢椎脱位有限元模型的建模方法及其在寰枢椎脱位临床治疗中的作用.方法:在正常上颈椎三维非线性有限元模型的基础上结合临床实际寰枢惟脱位病例,应用有限元软件,建立横韧带断裂而不伴有齿状突骨折的寰枢椎前脱位有限元模型,进行有限元分析,测量并比较正常上颈椎模型和寰枢椎脱位模型在屈、伸、侧屈、旋转等工况下的活动度(ROM).结果:在正常上颈椎三维非线性有限元模型的基础上结合临床实际寰枢椎脱位病例建立的横韧带断裂不伴齿状突骨折的寰枢椎前脱位有限元模型外观逼真,几何相似性好,各个工况下的活动度较正常上颈椎模型明显增大,尤其是前屈增加了17.8°,后伸增加了13.7°.结论:寰枢椎脱位非线性三维有限元模型能够较好地模拟临床实际脱位病例,可用于临床对寰枢椎脱位患者的生物力学分析,从而指导制定寰枢椎脱位的治疗策略.     

对寰枢椎脱位外科分型及治疗策略的思考

正寰枢椎脱位(atlantoaxial dislocation,AAD)是指创伤、先天崎形、退变、肿瘤、炎症或手术等因素造成关节面失去正常对合关系、关节功能障碍和/或神经受压的解剖学异常状态,是上颈椎创伤和疾病的病理转归。寰枢椎关节是颈椎中活动功能最重要的关节之一,活动度大,灵活性高,稳定性相对差,是颈椎诸椎节中容易受损伤的部位。同时,寰枢椎毗邻延髓生命中枢,脱位可造成严重的神经功能障碍,甚至危及生命。受医疗科技水平、基础研究及临床应用研究的限制,至20世纪末,我国对寰枢椎脱位多采用保     

新型头环石膏固定联合手术治疗小儿寰枢椎旋转固定性半脱位

目的　介绍一种新型头环石膏背心固定器 ,并报告联合手术治疗小儿寰枢椎旋转固定性半脱位的疗效。方法　用这种技术治疗 8例小儿寰枢椎旋转固定性半脱位 ,根据临床需要 ,此固定器可行屈曲、伸展、侧屈和中立位撑开固定。结果　本组没有明显的手术并发症 ,经临床观察和随访 ,治疗效果满意。结论　此固定器是颈椎外科中很有效的一种外固定方法 ,具有操作简单、固定牢固和易于调整的优点。适宜联合手术治疗小儿寰枢椎旋转固定性半脱位。     

寰枢椎脱位合并颈椎后纵韧带骨化症的手术疗效分析

目的探讨寰枢椎脱位合并颈椎后纵韧带骨化症(OPLL)的手术疗效。方法 2012年5月—2015年10月共收治寰枢椎脱位合并颈椎OPLL患者10例,其中易复型寰枢椎脱位8例,采用后路寰枢椎固定融合并颈椎单开门椎板成形术治疗;不可复型寰枢椎脱位2例,采用经口前路松解复位、后路枕颈融合并颈椎单开门椎板成形术治疗。采用日本骨科学会(JOA)评分及其改善率评估临床疗效,采用C2~7 Cobb角、颈椎活动度(ROM)、脊髓有效空间(SAC)和椎管狭窄率等评估影像学疗效。结果所有手术顺利完成。10例患者术后随访18~42个月,平均27.3个月。术后和末次随访时颈椎JOA评分较术前明显增加,其中JOA改善率优5例,良3例,可2例,优良率为80.0%。术后及末次随访时,颈椎Cobb角及ROM下降。术后SAC较术前明显增加,椎管狭窄率较术前明显降低。术中、术后无严重并发症发生,1例患者发生术后C5神经根麻痹,1例患者发生术后切口感染,经非手术治疗均痊愈。随访过程中无颈椎不稳、内固定松动或断钉现象发生,末次随访时所有患者均获得骨性融合。结论寰枢椎脱位合并颈椎OPLL手术治疗近期疗效确切,并发症发生率低。     

上颈椎非融合固定技术的研究进展

上颈椎包括寰椎和枢椎,主要涉及寰枕关节和寰枢关节,上承头颅,下接下位颈椎,生物力学复杂。颈椎具有旋转、屈伸和侧屈的运动功能,旋转运动的一半主要来自上颈椎的寰枢关节,屈伸主要来自寰枕关节。上颈椎损伤多由身体或头部加速撞击到静止物体上所致,主要包括寰枕关节脱位、寰枢关节脱位、寰椎骨折、枢椎齿状突骨折、枢椎创伤性滑脱和以上病变的叠加损伤。传统治疗上颈椎损伤的术式主要是寰枢椎融合术和枕颈融合术,但植骨融合技术在稳定结构的同时,导致上颈椎大部分活动度的丧失,旋转、屈曲等功能明显受限。上颈椎活动度的丧失对颈椎的生理和生物力学产生长期的负面影响,并对患者的生活质量产生不利影响。近年来,随着非融合理念和技术的推广,人工寰齿关节、经椎弓根动态固定系统等上颈椎非融合固定方式开始出现,以达到不植骨融合就可以同时实现稳定上颈椎结构和保留一定活动度的治疗目的。为进一步了解上颈椎非融合固定技术的研究进展,笔者对其做一综述。     

新型头环石膏固定联合手术治疗小儿寰枢椎旋转固定性半脱位

目的 介绍一种新型头环石膏背心固定器,并报告联合手术治疗小儿寰枢椎旋转固定性半脱位的疗效。方法 用这种技术治疗８例小儿寰枢椎旋转默写性半脱位,根据临床需要,此固定器可行屈曲、伸展、侧屈和中立位撑开固定。结果 本组没有明显的手术并发症,经临床观察和随访,治疗效果满意。结论 此固定器是颈椎外科中很有效的一种外固定方法,具有操作简单、固定牢固和易于调整的优点。适宜联合手术治疗小儿寰枢椎旋转固定性半脱位。     

寰枢椎不稳或脱位的诊断与治疗

头部和颈椎在遭受强的外力作用下可发生急性寰枢椎脱位 ,使颈髓和延髓受压 ,引起致死性损伤。对因各种非外伤性疾患所致的寰枢椎脱位 ,近年来也逐渐有所认识。在名称上也有称“寰枢椎脱臼”或“寰枢关节脱臼 (ａｔｌａｎｔｏ ａｘｉａｌｄｉｓｌｏｃａｔｉｏｎ)”、“寰枢椎半脱臼 (ａｔｌａｎｔｏ ａｘ ｉａｌｓｕｂｌｕｘａｔｉｏｎ)”或者称“寰枢椎关节不稳定 (ａｔｌａｎｔｏ ａｘｉａｌｉｎｓｔａｂｉｌｉｔｙ)” ,但使用“寰枢椎脱位”者较多。按其脱位的方向 ,有向前方脱位、向后方脱位、旋转脱位、侧方脱位 (罕见 )及垂直脱位 (类…     

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.     

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.     

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.     

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.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

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.     

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.