颈椎后路侧块钢板内固定术的疗效观察

[目的]研究颈椎侧块钢板固定治疗颈椎伤病中的疗效。[方法]采用颈椎侧块钢板并采用Magerl技术植入侧块螺钉。[结果]随访6～28个月，平均13个月。12例均获得牢固固定。合并脱位的获得完全复位，合并完全性截瘫神经功能恢复不明显，不全截瘫Frankel评分平均改善1．6级。发现螺钉松动1例，无钢板、螺钉断裂。[结论]在治疗颈椎伤病的后路手术中，侧块固定有手术安全、操作简单、固定确实、并发症少的优点，有一定的应用价值。     

颈椎侧块固定治疗下颈椎骨折脱位

目的 研究颈椎侧块钢板固定治疗下颈椎骨折脱位的临床疗效。方法 采用颈椎侧块钢板治疗下颈椎骨折脱位32例，其中Roy—Camille钢板22例，AXIS钢板10例，分别采用Roy—Camille技术和Magerl技术植入侧块螺钉。结果 32例均获得牢固固定，合并脱位的17例，13例获得完全复位，合并完全性截瘫者神经功能恢复不明显，不全性截瘫者14例基本恢复，发现螺钉松动4例，无钢板、螺钉折断。结论 在治疗下颈椎骨折脱位的后路手术中，侧块固定有手术安全，操作简单，固定确实，并发症少的优点，有一定的应用价值。     

颈椎侧块钢板内固定术治疗颈椎骨折脱位

目的：颈椎侧块钢板在颈椎骨折脱位内固定治疗中的作用。方法：颈椎骨折脱位的患者先行颅骨牵引且均不复位，采用切开复位颈椎后路侧块钢板内固定，根据颈椎侧块进钉点的不同采用相应的钢板及螺钉固定。结果：本组8例，随访10个月3年，植骨处已达骨性愈合，复位良好，内固定无松动断裂。结论：颈椎侧块钢板在颈椎骨折脱位治疗中其固定可靠，操作简单副损伤小。     

单开门加侧块钢板内固定治疗脊髓型颈椎病

目的研究颈后路单开门加侧块钢板内固定治疗脊髓型颈椎病合并颈椎不稳的临床疗效、侧块钢板固定的特点、必要性以及手术要点。方法2000年2月至2002年2月采用颈后路单开门加侧块钢板内固定治疗脊髓型颈椎病合并颈椎不稳22例,单节段不稳15例,双节段不稳6例,三节段不稳1例。结果本组22例随访6月-1年,术后优良率达90．9％,无1例出现内固定松动、椎动脉损伤、颈神经损伤及颈髓损伤等并发症。结论单开门加侧块钢板内固定治疗脊髓型颈椎病合并颈椎不稳具有入路安全、经椎管减压彻底同时又可增强颈椎稳定性等特点,是治疗脊髓型颈椎病合并颈椎不稳的一种较好的方法。     

颈椎侧块钢板螺钉固定术治疗颈椎失稳

为治疗颈椎失稳症,采用颈椎侧块钢板螺钉固定术治疗颈椎失稳症9例,通过6～26个月随访,均固定牢靠,融合良好。结果见颈椎侧块钢板螺钉固定对颈椎侧块具有牢固固定作用,同时对滑脱有良好的复位作用。认为后路颈椎侧块钢板螺丝钉固定加植骨是治疗颈椎失稳症的可靠方法。     

颈椎侧块钢板螺钉固定术治疗颈椎失稳

为治疗颈椎失稳症,采用颈椎侧块钢板螺钉固定术治疗颈椎失稳症９例,通过６～２６个月随访,均固定牢靠,融合良好,结果见颈椎侧块钢板螺钉固定对颈椎侧块肯牢固固定作用,同时对滑脱有良好的复位作用,认为后路颈椎侧块钢板螺丝固定加植骨是治疗颈椎失稳症的可靠方法。     

强直性脊柱炎颈椎骨折的治疗

目的：探讨强直性脊柱炎（AS）患者颈椎骨折的治疗方法及效果。方法：回顾分析1990年1月～2003年12月收治的20例AS合并颈椎骨折患者，7例采用非手术治疗，1例采用前路AO钢板内固定，5例采用前后路联合固定，2例行后路侧块螺钉内固定，5例采用颈椎椎弓根螺钉固定。手术组术前Frankel分级A级3例．B级5例，C级3例，D级1例，E级1例；非手术组术前Frankel分级A级2例，B级2例，C级1例，E级2例。结果：非手术组中5例有神经症状者3例死亡．2例无恢复；平均4．8个月获得骨性融合。手术组中1例行前路手术者，术后第3天钢板脱出，改行前后路联合内固定融合；5例前后路联合内固定患者中，1例术中牵拉致喉返神经损伤，术后3个月自行恢复，1例死亡，其余患者术后平均3．4个月骨性融合。2例后路侧块螺钉同定者术后平均4．1个月骨性融合。5例行颈椎弓根螺钉固定者术后平均3．6个月骨性融合。手术组12例有神经症状者中1例死亡，9例有不同程度的改善。结论：AS伴颈椎骨折采用非手术治疗术后神经损伤症状无明显改善，且存在复位困难、外固定不牢、易出现肺部感染等并发症。手术治疗可稳定脊柱、解除压迫及早期康复锻炼，可减少长期应用外固定及卧床所致的并发症。     

颈椎侧块钢板螺钉内固定治疗下颈椎骨折脱位

目的应用颈椎侧块钢板螺钉内固定术治疗下颈椎骨折脱位。方法应用该固定方法治疗下颈椎骨折脱位14例。其中单侧小关节骨折脱位3例，双侧4例；单侧小关节脱位2例，双侧4例；双侧小关节脱位合并椎体压缩骨折1例。无神经根损伤者3例，仅合并神经根损伤者5例，合并脊髓损伤者6例（完全性2例，不完全性4例）。切开复位，将螺钉固定于颈椎侧块上，配以钢板连接和植骨，实现坚强固定。结果本组14例随诊时间为8～40个月，平均28个月。平均融合时间是6个月。术后2周可在围领保护下坐起，术中无血管、神经损伤。单纯神经根损伤者症状完全消失，4例脊髓不完全损伤者Frankel分级提高1级。结论颈椎侧块钢板螺钉内固定术具有固定节段短，固定作用强，术后仅需一般外固定，可早期活动等优点。     

颈椎椎管内外生长的哑铃型肿瘤的手术治疗

目的探讨颈椎椎管内外生长的哑铃型肿瘤的显微外科手术及颈椎前路减压钛网植入锁定钢板内固定和颈椎后路侧块螺钉钢板固定两者联合治疗的方法和特点。方法分析13例颈段哑铃型椎管内肿瘤病人的临床特点、影像学特征、显微手术及颈椎前路减压钛网植入锁定钢板内固定和颈椎后路侧块螺钉钢板固定两者联合治疗的方法与治疗结果。结果 13例患者术前MRI检查明确诊断,CT颈椎重建明确肿瘤相邻颈椎椎体及其附件的破坏程度。所有患者均行显微手术切除肿瘤,同时行颈椎前路减压钛网植入锁定钢板内固定加颈椎后路侧块螺钉钢板固定的方法。肿瘤全切11例,部分切除2例,所有患者术后颈椎稳定性良好。结论颈椎椎管内外生长的哑铃型肿瘤往往伴有不同程度的椎体及其附件的破坏,单纯切除肿瘤会造成颈椎稳定性受损,患者需要行颈椎前路减压钛网植入锁定钢板内固定和颈椎后路侧块螺钉钢板固定两者联合治疗的方法,以防术后颈椎不稳而造成脊髓压迫。     

经后路联合使用侧块钢板螺钉和椎弓根钉内固定治疗下颈椎损伤

目的探讨经颈后正中人路联合使用侧块钢板螺钉和T．椎弓根钉内固定手术在治疗下颈椎C6～C7损伤的应用。方法应用此项技术治疗下颈椎损伤8例。其中,C6-7 6例,C7 2例。术前ASIA分级3例为C级,5例为D级。手术采用颈椎侧块钢板螺钉和T1椎弓根钉联合内固定。结果本组8例患者平均随访15个月(5～37个月),术后脊髓损伤无加重,脊髓功能均有改善,无血管、神经并发损伤。结论经颈后正中人路联合颈椎侧块钢板螺钉和椎弓根钉内固定是治疗下颈椎损伤的一种好方法。     

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 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.     

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.