腰椎间盘突出症再手术中预防性神经根管扩大作用的研究

目的探讨腰椎间盘突出症再手术的原因,及对术中预防性神经管扩大的作用进行了研究。方法选择自1995年9月～12月,共计有48例腰椎间盘突出症再手术的患者。在摘除髓核后,对合并神经根管狭窄者,行神经根管开大,使神经根得到充分减压,对不合并神经根管狭窄者,行上关节突内侧壁潜行咬除,扩大了神经根管的容积,为神经根通道提供了储备空间。结果经平均随访4年,据改良的Macnab疗效评定标准,优良45例,可2例,差1例,优良率93．7％。结论再手术的原因主要是同节段的复发和邻近节段的再发及病变节段神经根管狭窄。再手术时,在摘作髓核后,应行预防性神经根管开大以提高腰椎间盘突出症再手术的远期疗效。     

手术治疗老年腰椎间盘突出症32例报告

目的 报告手术治疗老年性腰椎间盘突出症的手术方式及疗效。方法 本组32例均行了手术治疗,其中椎板开窗髓核摘出12例,半椎板切除加椎间关节内侧部份切除侧隐窝扩大神经根管扩大髓核摘除14例,保留棘突的全椎板切除,神经根管扩大侧隐窝扩大髓核摘除6例。结果 随访1－4年,优良21例,差11例,差者为采用单纯椎板开窗髓核摘出术术式者,术后远期疗效差。结论 老年腰椎间盘突出大多伴有腰椎管狭窄,在髓核摘出的同时,应行半椎板或双侧椎板切除减压,侧隐窝扩大,视术中情况是否神经根管扩大。     

ETRX手术系统治疗腰椎间盘突出症早期疗效观察

报道应用METRX椎间盘镜手术系统治疗腰椎间盘突出症 6 4例 ,行髓核摘除和神经根管扩大术。随访 3月～ 19月 ,平均 11个月。按Nakai分级 :优 5 6例 ,良 6例 ,可 2例。并发症 5例 ,其中硬脊膜损伤 3例 ,神经根牵拉伤 1例 ,髓核残留 1例。     

显微椎间盘镜治疗合并神经根管狭窄的腰椎间盘突出症

目的分析内镜下后路椎间盘髓核摘除，神经根减压、松解术冶疗合并腰椎管狭窄的椎间盘突出症的临床疗效。方法对合并侧隐窝及神经根管狭窄的腰椎间盘突出症58例，采用后路显微内镜（MED）下髓核摘除、神经根管扩大术治疗。结果术后58例症状均明显改善，未出现损伤椎体前方大血管、神经症状加重、脑脊液外漏和感染等近期并发症和复发、腰椎失稳等远期并发症。结论内镜下后路髓核摘除术是外科治疗椎间盘突出症的一种优良方法，对合并神经根管狭窄病例，正确把握手术适应证，发挥微创技术的优越性，同样可以取得满意疗效。     

腰椎间盘退变性疾病术后短期内再手术原因分析与疗效

目的探讨腰椎间盘退变性疾病手术后短期内再次手术的原因及干预方法。方法 2010年8月至2011年2月手术治疗腰椎管狭窄症、腰椎间盘突出症等腰椎间盘退变性疾病238例,手术方式包括髓核摘除、椎管减压、椎间融合、椎弓根螺钉内固定等。术后7例因腰腿痛及神经根性症状持续存在或加重在短期内进行再次手术,其中男2例,女5例,年龄47～67岁。再手术原因包括神经根管减压不充分伴髓核组织残留2例,椎弓根螺钉误置2例,椎间融合术后相邻节段退变2例,椎板切除减压、髓核摘除术后椎间不稳1例。结果 7例手术均顺利完成,有效随访6～12个月,术后视觉模拟疼痛评分和Oswestry功能障碍指数评分均有改善,腰腿痛及神经根性症状有所缓解,疗效满意。结论游离型腰椎间盘突出症容易发生髓核组织残留致神经根管减压不充分、椎弓根螺钉误置;要重视腰椎融合术后相邻节段退变发生的相关因素,有效预防和延缓相邻节段退变的发生。     

腰椎间盘突出症再手术的原因及对策

目的　分析腰椎间盘突出症再手术的原因 ,评价预防性神经根通道扩大的作用。方法　自 1975年～ 2 0 0 1年共对 5 6例腰椎间盘突出症患者进行了再手术治疗。术中摘除髓核 ,对存在神经根通道狭窄者 ,扩大神经根通道 ,使神经根充分游离 ;对无明显神经根受压者 ,用薄斜口冲击咬骨钳紧贴内侧壁潜行咬除侧隐窝壁及上关节突内侧半 ,扩大神经根通道的储备空间。对存在椎间不稳同时行椎间融合 ,BAK植入术。结果　经平均 5 1年随访 ,按改良Macnab疗效评定标准 ,优良 5 1例 ,可 2例 ,差 3例 ,优良率 91 1%。结论　再手术的主要原因是同间隙复发及病变节段神经根通道狭窄。再次手术治疗 ,在尽量摘除髓核的同时 ,预防性神经根通道扩大可以有效提高腰椎间盘突出症再次手术的远期疗效 ,对于椎间不稳可同时行椎间融合术。     

扩大开窗双节段神经根管减压在腰椎间盘突出症手术中的应用

目的 观察扩大开窗双节段神经根管减压加髓核摘除术治疗腰椎间盘突出症的临床疗效。方法 选择196例腰椎间盘突出症患者,采用扩大开窗,咬除该间隙上椎板下方约2／3,下椎板上方约1／3,凿除上下关节突内侧1／3,向下扩大下一节段神经根管,向上扩大同一节段神经根管,常规摘除髓核组织。结果 本组观察3月至五年,随诊率90％,根据Macnab疗效评定标准：优123例,良63例,可6例,差3例,优良率94．8％。结论 腰椎间盘突出症髓核摘除术后椎间隙高度均有不同程度的丢失,从而改变椎间孔的形态,增加神经根卡压的危险性,采用扩大开窗双节段神经根管减压可避免神经根管狭窄而造成的神经根卡压症状,从而提高手术的远期疗效。     

有限化手术治疗原位复发性腰椎间盘突出症

目的 :探讨有限化手术治疗原位复发性腰椎间盘突出症的方法。方法 :经原切口显露 ,切除残留椎板和关节突内侧部分 ,扩大残留骨窗 ,从侧方入路分离 ,显露硬膜囊和神经根的外侧 ,紧贴椎弓根内侧缘 ,由远至近分离神经根 ,摘除突出髓核 ,扩大神经根通道 ,旷置处理瘢痕。结果 :本组共 3 6例 ,经 1～ 5年 ,平均 2 5年随访 ,无脊柱失稳。根据日本N Nakano和T Nakano腰背痛手术评定标准 ,优 2 7例 ,良 6例 ,可 3例 ,优良率 91 7%。结论 :采用原位扩大开窗显露 ,有限化手术治疗原位复发性腰椎间盘突出症安全可行 ,能有效解除神经压迫 ,创伤小 ,有利于脊柱稳定     

腰椎间盘突出术后原位间隙再脱出

目的 探讨术后原位复发性腰椎间盘突出症的发生机理。影像学特征和治疗方法。方法 12例病人均行再次手术治疗，采用原切口显露椎板残端进入椎管并将神经根通道做适当扩大，摘除髓核并对狭窄的神经根管进行减压，没有切除瘢痕组织。结果 本组10例经平均4.6年随访，优6例。良2例。可2例。优良率为80%。结论 椎间盘术后原位复发的主要原因是髓核遗留过多，影像学检查上MRI较CT更能清晰显示髓核突出的范围及大小，原位切口显露法摘除髓核可有效地去除病因，损伤小疗效满意，并对脊柱稳定性有利。     

手术治疗高位腰椎间盘突出症60例

目的探讨高位腰椎间盘突出症的临床特点、诊断及治疗方法。方法60例高位腰椎间盘突出症患者中,15例行全椎板减压髓核摘除内固定,8例行半椎板减压髓核摘除,7例行双侧开窗髓核摘除,3例行经峡部外缘入路髓核摘除,27例行单侧开窗髓核摘除（其中神经根管扩大6例）。结果60例均获随访,时间6～36个月。术中硬脊膜破裂脑脊液漏3例,无神经损伤病例出现。参考陆裕朴疗效评定标准：优50例,良8例,可2例,优良率96.7%。结论高位腰椎间盘突出症的临床表现复杂,应根据临床查体结合影像学检查选择手术入路。对于年轻、单节段及旁侧型的椎间盘突出症者选择单侧开窗或半椎板减压髓核摘除;对多间隙、中央型突出髓核大者选择双侧开窗或全椎板减压髓核摘除加内固定。     

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.