应用METRx椎间盘镜治疗极外侧型腰椎间盘突出症

目的总结应用METRx椎间盘镜治疗极外侧型腰椎间盘突出症的临床疗效。方法1999年2月至2002年12月,采用METRx椎间盘镜行髓核摘除术,治疗极外侧型腰椎间盘突出症14例,均为单间隙突出,其中男性10例、女性4例,年龄41-55岁,平均49岁。突出间隙：L4,5 6例、L5-S1 8例。突出类型：椎间孔突出型6例,椎间孔外侧突出型8例。结果14例随访12—46个月,平均26．5个月。疗效：优10例、良3例、可1例。术后4例遗留感觉障碍,无神经根损伤、椎问盘炎、硬膜囊撕裂、椎间盘突出复发等并发症。结论应用METRx椎间盘镜治疗极外侧型腰椎间盘突出症,手术创伤小、神经根减压彻底和术后恢复快,适用于极外侧型腰椎间盘突出症的治疗,选择正确的手术入路和术中仔细的操作是手术成功的关键．     

显微椎间盘镜行双间隙髓核摘除术治疗复合型腰椎间盘突出症

目的 探讨脊柱后路显微椎间盘镜行双间隙椎间盘髓核摘除术治疗复合型腰椎间盘突出症的手术入路和疗效。方法 在应用脊柱后路显微椎间盘镜为282例腰椎间盘突出症患者进行髓核摘除术中，选择L4-5、L5S1，复合型椎间盘突出者52例(18．4％)，采用同侧双切口入路或不同侧双切口入路对同侧或不同侧相邻的双间隙椎间盘突出者做髓核摘除术。结果 接受本手术入路治疗的52例复合型椎间盘突出症者，其建立工作通道的成功率为100％、行显微椎间盘镜髓核摘除的优良率为96．1％。结论 以同侧或不同侧作双切口入路在椎间盘镜下作相邻双间隙椎间盘突出髓核摘除术治疗复合型腰椎间盘突出症创伤小、恢复快，具有创新性和实用性。     

42例椎间盘镜下髓核摘除术早期疗效

目的：探讨椎间盘镜下腰椎间盘髓核摘除术的手术要点和早期疗效。方法：显微内窥镜椎间盘切除术(microendoscopic discectory,MED)在椎间盘镜直视下对42例单间隙腰椎间盘突出症患者行突出髓核摘除术，并进行疗效分析。结果：42例获随访，时间3—24个月(平均10个月)。疗效优38例，良3例，可1例。无差级疗效及相关并发症发生。结论：椎间盘镜下腰椎间盘髓核摘除术创伤小，患者术后恢复快，疗效肯定，是治疗腰椎间盘突出症的有效方法之一。     

椎间隙冲洗在腰椎间盘突出症手术中的意义

目的探讨椎间隙冲洗在腰椎间盘突出症髓核摘除术中的意义。方法随机选取腰椎间盘突出症髓核摘除手术患者共80例83个椎间隙，其中L4-5间隙35例，L5S1间隙40例，L3-4间隙2例，L4-5L5S1双间隙3例。行开放式手术38例，椎间盘镜下手术42例。采用椎间冲洗43例，未冲洗37例。结果术后仍感腰腿疼痛者18例，均为未行椎间隙冲洗者，疼痛持续1～8个月自行消失，平均3个月；行椎间隙冲洗者术后无一例出现腰腿痛。术后随访6个月至2年，平均8个月，无腰椎间盘突出症复发者。结论腰椎间盘突出症髓核摘除术加椎间隙冲洗对术后腰腿疼痛有显著的预防作用。     

椎间盘镜下腰椎间盘髓核摘除术的疗效

目的 探讨椎间盘镜下腰椎间盘髓核摘除术的手术要点和早期疗效。方法 在椎间盘镜直视下对50例单间隙腰椎间盘突出症患者行突出髓核摘除术，并进行疗效分析。结果 患者均在术后10天出院，平均随访9.34个月，临床疗效优良率96%，无严重手术并发症，术后CT检查显示突出椎间盘已摘除，脊髓及神经根已获得充分减压。结论 椎间盘镜下腰椎间盘髓核摘除术创伤小，患者术后恢复快，疗效肯定，是治疗腰椎间盘突出症的有效方法之一。     

显微内窥镜下椎间盘切除术治疗腰椎间盘突出症的并发症及其处理

目的：总结显微内窥镜下椎间盘切除术（microendoscropic discectomy，MED）治疗腰椎间盘突出症中出现的并发症，探讨其处理对策。方法：1999年10月至2006年12月采用MED治疗腰椎间盘突出症患者1852例，其中单间隙椎间盘突出1737例，L2／310例，L3／419例，L4，51013例，LS／S1695例；双间隙椎间盘突出115例，L3／4和L4／511例，L4／5和LS／S1104例；中央型突出161例，旁中央型923例，外侧型696例，极外侧型72例。观察术中和术后并发症及其处理。结果：术中发生椎管内静脉丛出血48例，42例通过镜下止血后完成髓核切除，6例改为开放椎间盘切除术；定位错误47例，术中发现后调整内窥镜位置完成手术：硬脊膜破裂21例，2例改为开放手术；髓核遗漏13例，二期再次行髓核切除术；神经根损伤6例，术后3个月内完全恢复。1295例患者获得3—69个月的随访，平均随访13个月，出现椎间感染6例，2例保守治疗，4例行椎间病灶清除术，均痊愈；术后复发32例，11例再次应用MED治疗，21例行开放椎间盘切除手术．并对其中的8例采用椎间植骨、单侧腰椎弓根螺钉固定术，术后症状缓解；术后遗留活动后明显腰部疼痛124例．腰椎CT检查未见明显的腰椎间盘突出及神经根压迫，经过止痛药物、腰背肌锻炼及物理治疗后好转。结论：熟练精细的操作技术、充分的术前准备及正确的手术适应证选择是减少显微内窥镜下腰椎间盘切除手术并发症的重要环节。     

椎间盘镜治疗腰椎间盘突出症80例分析

目的 探讨椎间盘镜系统治疗腰椎间盘突出症的手术适应症、手术方法及近期疗效。方法 应用Rudolf椎间盘镜系统手术治疗腰椎间盘突出症80例,87个椎间盘。L3-4 6间隙、L4-5 33间隙、L5-S1 48间隙。双间隙突出7例,合并椎管狭窄8例,纤维环破裂18例。平均椎间盘手术55分钟,平均椎间盘出血量45ml。结果 手术随访平均13个月,（3～26个月）,优67例、良10例、可3例、优良率96．25％,并发症：硬膜破裂1例,神经牵拉伤1例,椎间盘感染1例,遗漏游离髓核1例。结论 椎间盘镜系统治疗腰椎间盘突出症手术视野清楚,出血少,术后恢复快,对脊柱稳定结构损伤小,疗效佳。     

常规及改良式椎间盘镜治疗腰椎间盘退变性疾病的疗效分析

目的观察常规椎间盘镜及改良式椎间盘镜手术治疗腰椎间盘退变性疾病的疗效。方法2006年10月至2010年6月用显微椎间盘镜髓核摘除术共治疗136例腰椎间盘突出症,154个间隙腰椎间盘突出。单节段突出者118例,双节段者18例,合并神经根管狭窄者41例,合并椎管狭窄症者15例,合并突出物钙化11例,合并软骨板撕脱者6例。合并腰椎失稳4例,中央型巨大突出25例,脱垂游离型16例。其中男性87例,女性49例,发病年龄16-73岁,平均42．1岁。突出间隙：L3-412例,L。-s52例,LsS1,54例。L3-4加L4-53例,L4-5加LsS1 15例。结果所有患者均获得6-24个月的随访,平均12个月。优良率94．1％。结论常规椎间盘镜及改良式椎间盘镜下手术治疗腰椎间盘退变性疾病,具有创伤小、恢复快、神经根减压彻底、维护脊柱稳定性优点。术前诊断明确、适应证选择合适并及时手术、手术方式选择正确、术前与术中相吻合及术中耐心细致的操作是手术成功的关键。而改良术式作为常规椎间盘镜术的补充,可以扩大椎间盘镜在临床的应用范围,减少术中中转开放的概率,最大程度用微创术服务于患者。     

治疗腰椎间盘突出症三种术式的疗效比较

目的 比较经皮腰椎间盘髓核摘除术(automated pereutaneous lumbardiscectomy，APLD)、经后路显微内窥镜椎间盘髓核摘除术(microendoscopic discectomy，MED)、传统开窗椎间盘髓核摘除术3种术式对腰椎间盘突出症的治疗效果。方法 在相同时间段内，3组病例采用统一的选择标准、疗效评定标准、手术由专人操作。结果 均获12个月以上的随访，用Ridit分析法对3种治疗结果进行比较。结论 APLD是治疗包容性腰椎间盘突出症的较好方法；MED治疗腰椎间盘突出症是传统手术的微创化，其手术技能基本同传统开窗椎间盘髓核摘除术，可作为单间隙旁侧型腰椎间盘突出症手术治疗的首选术式。     

坐俯卧位显微椎间盘镜治疗腰椎间盘突出症及腰椎侧隐窝狭窄症

目的探讨后路显微椎间盘镜治疗腰椎间盘突出症及腰椎侧隐窝狭窄症的临床效果：方法手术均取坐俯卧位,经椎板间隙只切除黄韧带不切除椎板及其它结构,应用椎间盘镜及显微外科的技术摘除突出之髓核和／或神经根减压术：临床应用649例。结果术后所有病例均获随访,随访最长时间24个月,最短6个月,平均12个月,按Nakai标准评定,其中优594例,良45例。结论侧卧位经椎板间隙入路行椎间盘镜治疗腰椎间盘突出症及腰椎侧隐窝狭窄症的手术损伤小、出血少,术后不影响脊柱稳定性,临床疗效可靠。     

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.