单侧半椎板入路切除神经鞘瘤17例

目的探讨单侧半椎板入路切除椎管内神经鞘瘤中的方法及效果。方法回顾性分析采用单侧半椎板入路切除椎管内神经鞘瘤17例的临床资料。结果 17例患者均行肿瘤全切,术后随访3~24个月,13例临床症状消失或明显改善,3例部分缓解,1例无明显变化,无肿瘤复发、椎体滑脱和脊柱畸形患者。结论单侧半椎板入路切除椎管内神经鞘瘤疗效可靠、创伤小、恢复快、对脊椎稳定性影响小。     

单侧部分椎板切除入路显微手术治疗椎管内肿瘤

目的 探讨单侧部分椎板切除治疗椎管内肿瘤对脊柱稳定性的影响和适应证的选择。 方法 对2005年10月至2010年12月椎管肿瘤45例患者采用单剥离一侧椎旁肌,单侧部分椎板切除微创入路,应用显微外科技术切除肿瘤,回顾分析临床资料及随访结果。 结果 神经鞘瘤19例、脊膜瘤11例、神经纤维瘤4例、表皮样囊肿3例和畸胎瘤3例均手术全切除,胸椎管内表皮样囊肿l例和脊髓圆锥部畸胎瘤4例残留少许包膜或瘤体。随访3个月～6年,失访4例。术中肿瘤全切除者无肿瘤复发。1例因胸腔积液肺不张致脊柱畸形。其余病例均无因手术而继发畸形。 结论 单侧部分椎板切除入路治疗椎管内肿瘤损伤小,最有利于脊柱稳定性的维持。对于椎管内与脊髓无粘连可分离的肿瘤,选用单侧部分椎板切除入路切除,可获得较好临床效果。     

后路椎间盘镜显微治疗腰椎椎管狭窄症

目的 报道显微后路椎间盘镜治疗退行性腰椎椎管狭窄症的临床效果。方法 选取退行性腰椎管狭窄症病例，椎板间隙入路椎间盘镜下行椎管减压，单侧单节段开窗减压23例，双侧单节段开窗减压12例，单侧双节段开窗减压9例，单侧双节段半椎板切除减压4例。结果 除1例术中硬膜破裂改常规手术外，其余病例均在手术显微镜下完成腰椎管减压术。所有病例获得5～18个月随访，平均8．3个月，优良率92％。结论 显微后路椎间盘镜治疗退行性腰椎管狭窄症具有手术创伤小、神经根减压彻底、术后恢复快的特点；单纯腰椎间盘膨出或突出、黄韧带肥厚和小关节增生引起的退行性腰椎管狭窄症是其适应证。     

颈椎硬膜内髓外肿瘤手术治疗方式选择

目的 探讨颈椎硬膜内髓外肿瘤的手术方式及钛网椎管重建的效果.方法 2002年3月至2008年9月手术治疗颈椎硬膜内髓外肿瘤26例,男14例,女12例;年龄6～76岁,平均38岁.术前神经功能Frankle分级,B级3例,C级8例,D级11例,E级4例.16例行半椎板切除(半椎板组),10例全椎板切除后行钛网椎管重建(全椎板组).术后随访6个月～5年,平均26个月,记录术后神经恢复及植骨融合情况.确认植骨融合后(术后6个月),对半椎板组和全椎板组病例手术前后的颈椎曲度指数、颈椎活动度进行评估.结果 术后神经功能恢复Frankle分级均有改善.术前Frankle分级B级3例,术后提高到C级;术前C级8例提高到D级;术前D级11例提高到术后E级10例、D级1例.全椎板组钛网表面植骨块与上、下椎板融合,术后脊柱稳定,未发生畸形.半椎板组术后颈椎曲度指数丢失2.2±2.3,全椎板组术后颈椎曲度指数丢失4.3±2.5,两组患者手术前后颈椎曲度变化的差异有统计学意义(t=2.05,P＜0.05).半椎板组术后颈椎活动度丢失1.3°±1.2°,全椎板组患者术后颈椎活动度丢失9.2°±4.1°,两组差异有统计学意义(t=1.71,P＜0.05).结论 颈椎硬膜内髓外肿瘤体积小位于椎管一侧,适宜选择半椎板切除.对于需要行全椎板切除的病例,内固定及钛网椎管重建加植骨,可以重建脊柱的稳定性.     

显微镜下微通道锁孔技术在椎管肿物手术中的应用

目的探讨微通道锁孔技术在椎管内肿瘤切除术中的应用价值。方法回顾性分析2017年2月～2018年9月34例椎管内髓外肿物的临床资料,包括腰骶椎肿瘤26例,颈椎肿瘤4例,胸椎肿瘤4例,长径0. 5～2 cm。采用显微镜下微通道锁孔技术联合半椎板切除或半侧椎板间开窗技术进行手术。结果半椎板切除25例,半侧椎板间开窗9例。肿瘤均获全切除,手术时间60～120 min,平均87 min。术后病理为神经鞘瘤26例,皮样囊肿、表皮样囊肿3例,单纯囊肿3例,脊膜瘤2例。术后无感染、脑脊液漏,无神经功能障碍加重。术后住院时间3～7 d,平均5. 4 d。术后随访3～12个月,中位数6个月,未见脊柱不稳定或畸形,未见肿瘤复发或残留。按McCormick分级,均为Ⅰ级。结论两个节段以下的髓外肿瘤通过微通道技术可Ⅰ期全切。微通道技术有利于保留脊柱的正常结构和肌肉附着,有利于保持脊柱的完整性及稳定性。     

微创半椎板入路切除颈椎管内脊髓腹侧肿瘤

目的探讨微创半椎板入路切除颈椎管内脊髓腹侧肿瘤的手术效果。方法 2007年7月～2019年6月,对36例颈椎管内脊髓腹侧肿瘤,在保持项韧带、棘上韧带及棘间韧带完整的基础上,经后路行半椎板显露、切除,显微镜下切除肿瘤。结果 36例椎管内肿瘤均获全切,手术时间90～246 min,平均120 min;出血量90～600 ml,平均200 ml;无手术并发症。术后住院时间3～9 d,平均6 d。术后病理:神经鞘瘤23例,脊膜瘤11例,肠源性囊肿2例。36例随访6个月～10年,中位随访时间5.3年,其中6个月～3年9例,3～5年10例,5～10年17例,末次随访按McCormick分级标准:Ⅰ级35例,Ⅱ级1例,MRI示肿瘤无复发。结论对大多数颈椎管内脊髓腹侧肿瘤,经后路半椎板入路切除,手术对肿瘤显露及切除效果满意。     

腰椎椎管内原发性肿瘤的显微手术治疗

目的 探讨应用显微手术治疗腰椎椎管内原发性肿瘤的临床效果。方法 在精确的定位下，采用单侧椎板开窗、中央开窗和全椎板切除等手术方式，在显微镜下操作切除肿瘤23例。结果 肿瘤完全切除21例，大部分切除2例。术后17例腰部及下肢疼痛症状消失，6例疼痛症状减轻。所有病例术后3d可坐起，7d后带腰围下地活动。术后随访6个月-4年3个月，平均2．6年。21例病例无复发，可正常生活和工作；2例仍存在轻度的神经功能障碍，生活基本自理。结论 早期诊断和治疗是恢复脊髓功能的最有效方法。采用显微手术治疗能最大限度减少或避免脊髓损伤的发生。     

单侧开窗治疗椎管内肿瘤

单侧开窗治疗椎管内肿瘤王晨阳，戴琳孙，林章雅，陈锦峰，张义成脊柱后部结构破坏对脊柱稳定性的影响日益受到重视。１９９０年９月～１９９４年７月我院采用单侧开窗术治疗椎管内肿瘤１５例，改变了传统手术之全椎板切除，以求最大限度地保持椎体后部结构的完整性，效果...     

不同椎管入路在后路脊柱显微内窥镜手术中的应用

目的总结不同椎管入路在后路脊柱内窥镜手术中的应用效果。方法回顾性分析445例后路脊柱显微内窥镜下腰椎间盘摘除患者的临床资料。其中,椎板间隙入路21例,椎板间开窗72例,侧隐窝入路233例,扩大开窗法39例,单侧多平面开窗法和双侧开窗法51例,半椎板切除29例。结果手术均获成功。最常见的并发症是术后患肢有短期麻木感,其中7例（33.3%）为椎板间隙入路,11例（15.3%）为椎板间开窗组。402例随访3-37个月,优305例,良78例,可13例;差6例,均为复发需再次手术治疗。结论各种椎管入路有其不同适应证,应根据不同的病理改变和所需要的暴露范围而选择。     

半椎板切除入路治疗颈椎管哑铃型肿瘤

目的 探讨微创手术切除颈椎管哑铃型肿瘤的可行性。方法 用半椎板切除入路显微手术治疗14例颈椎管哑铃型肿瘤。结果 全切肿瘤12例,次全切l例,大部切除l例。术中椎动脉保护完好,术后症状均有明显改善,有9例随访6个月至18个月,无一例复发及出现颈椎不稳的表现。结论 此术式不仅创伤小、出血少,且不影响颈椎的稳定性,对颈椎管哑铃型肿瘤是较佳的选择。     

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.