枕下乙状窦后-内听道上入路切除岩斜区脑膜瘤

目的介绍应用枕下乙状窦后-内听道上入路显微手术切除岩斜区脑膜瘤的显微手术技术。方法回顾性分析采用枕下乙状窦后-内听道上入路显微手术治疗的8例岩斜区脑膜瘤的临床资料,并对手术方法进行分析。结果肿瘤全切除6例,次全切除2例。术后新增脑神经损害2例,无手术死亡病例。结论枕下乙状窦后-内听道上入路是切除主体位于后颅窝、同时累及中颅窝的岩斜区脑膜瘤的安全有效的改良入路,娴熟的显微神经外科技术,熟练掌握入路的显微解剖可获得满意的手术疗效,有利于提高肿瘤切除率和疗效。     

乙状窦后锁孔入路对颅中后窝区的显微解剖

目的 研究乙状窦后锁孔入路对颅中后窝岩斜区结构的显微解剖,为临床应用该入路解决颅中后窝岩斜区病变提供解剖学依据. 方法 应用福尔马林固定的成人湿性头颅标本10例20侧,模拟乙状窦后锁孔入路对颅中后窝岩斜区进行显微解剖观察. 结果 乙状窦后锁孔入路从后外侧到达颅中后窝岩斜区,可以清楚暴露小脑半球外侧面、颞骨岩部、三叉神经、面听神经、部分后组脑神经、脑桥外侧面、椎动脉、小脑前下动脉.磨除部分岩骨可以扩大内听道及三叉神经的暴露,切开小脑幕缘可以暴露部分滑车神经及部分颅中后窝. 结论 乙状窦后经内听道上锁孔入路充分利用了有效的骨窗,手术创伤小、并发症少.该入路使少数原本需要采用复杂入路方能切除的颅中后窝肿瘤,可通过较简单的手术入路进行切除.对于主体位于颅后窝的岩斜区中小型肿瘤显微切除是一种有效、安全、便捷的微创手术方法.     

幕上下联合锁孔入路显露岩斜区的显微解剖

目的 研究颞下和枕下乙状窦后锁孔入路对岩斜区显露的互补性.方法 尸头上模拟该锁孔入路,颞部骨窗以颧弓根部为中心前后各1.5 cm,高2.5 cm,枕下乙状窦后骨窗直径3 cm,观察显露范围并用导航标记.用带有造影剂的明胶海绵标记适于操作的有效空间,再行CT扫描和三维重建.结果 颞下入路从前外侧到达岩斜区,对颅中窝、鞍旁、幕上桥前池、脚间池下部、环池前部显露佳,切开小脑幕后环池和桥前池下部视野得到扩展,桥小脑角池方向被岩尖遮挡,是显露的死角.枕下乙状窦后入路从后外侧到达岩斜区,对同侧桥小脑角、桥前池、环池后部显露佳,但Meckel's囊开口至海绵窦后部被内听道上结节遮挡,范围小于1 cm3.结论 颞下和枕下锁孔入路的显露空间和角度有互补性,联合运用有利于切除同时累及幕上下,侵犯上斜坡和中下斜坡的岩斜脑膜瘤,尽管对海绵窦后部显露不佳,但范围小,处于放射外科的有效治疗范围之内,达到微创疗效.     

岩斜区肿瘤手术入路选择的探讨

目的 探讨岩斜区肿瘤的手术入路选择。对53例岩斜区肿瘤患者的手术治疗进行分析。方法患者采用颞底经天幕入路11例,枕下乙状窦后入路12例;（颧弓或眶颧）翼点入路12例;乙状窦前入路2例;颞底、乙状窦后幕上下联合入路7例;颞下前岩骨硬膜外入路7例;扩大的前颅底硬膜外入路2例。结果32例（61％）患者肿瘤全切除,9例（17％）次全切除,12例（22％）大部切除。术后新发生颅神经功能障碍16例（30％）,死亡2例（4％）。结论枕下乙状窦后入路、颞底经天幕入路等岩斜区手术入路均可以在熟练的显微操作技术及神经导航、神经内镜下进行。主体生长于硬膜外的岩斜肿瘤适合于采用硬膜外入路手术切除。幕上下联合入路对巨大岩斜区肿瘤是理想的手术入路。     

幕上下联合入路切除岩斜区巨大肿瘤

目的:探讨岩斜区巨大肿瘤的手术入路和早期严重并发症的处理。方法:采取幕上下联合入路(颞下经小脑幕及枕下乙状窦后联合入路)对11例岩斜区巨大肿瘤进行手术治疗。结果:10例全切除,1例大部切除,效果满意。结论:有熟悉的解剖知识,采用颞下经小脑幕和枕下乙状窦后联合入路可以切除岩斜区巨大肿瘤。     

脑肿瘤

内窥镜经蝶窦入路垂体瘤切除术的临床观察；磁共振成像诊断海绵窦侵袭型垂体瘤(附39例报告)；采用扩大经蝶窦入路方法切除鞍区和斜坡巨大肿瘤；神经导航在经蝶显微切除侵袭性鞍区肿瘤手术中的应用；神经内镜辅助锁孔显微外科治疗颅内胆质瘤；垂体瘤术后水钠紊乱的治疗；经蝶窦垂体瘤切除手术入路的探讨；脑转移瘤的外科治疗；岩斜区脑膜瘤的临床治疗研究；复发垂体ACTH腺瘤的诊断和再次经蝶手术治疗；巨大型垂体腺瘤经颅入路显微外科治疗；组织定向活检诊断为胶质瘤与手术病理符合率的比较研究；荧屏监视下经鼻蝶窦穿刺治疗鞍内囊性肿瘤。     

桥小脑角大型脑膜瘤的显微手术治疗

目的探讨桥小脑角大型及巨大型脑膜瘤手术入路及显微手术切除方法方法回顾分析经显微手术治疗的28例桥小脑角大型及巨大型脑膜瘤：其中19例采用枕下乙状窦后入路，3例采用颞枕开颅乙状窦前入路，4例采用颞枕开颅颞下小脑幕入路，2例采用颞枕开颅与幕上、下联合入路：结果肿瘤全切除(SimpsonⅠ、Ⅱ级)22例，全切除率为78．6％。全组无手术死亡。术后症状改善者20例，症状基本同术前5例。26例随访6个月至4年，生活自理者23例(88．5%)，复发2例(7．7％)。结论合理选择手术入路，术中应用显微技术妥善处理和保护血管、神经、脑干等，能较理想地切除肿瘤和提高患者生存质量。     

乙状窦前经迷路锁孔入路的显微解剖

目的将微创锁孔理念融入乙状窦前入路，在神经导航辅助下，设计乙状窦前经迷路锁孔入路，观察入路显微解剖，为临床应用提供依据。方法采用8具经福尔马林固定、颅内动静脉乳胶灌注的国人成人尸头，实验前建立术中导航资料。采用迷路后锁孔手术入路的7cm“C”形切口，分层向前翻开皮瓣和肌筋膜瓣，在神经导航辅助下做耳后约3．5cm×3．0cm骨窗，导航下轮廓化乙状窦、骨迷路、面神经管，依次模拟迷路后、经部分迷路及岩尖、经全迷路锁孔入路，观察各步骤显露的结构，测量重要结构长度和术野角度。结果（1）神经导航可辅助精确磨除入路相关骨质，减少盲目磨除造成的重要结构的误伤。（2）同迷路后锁孔入路比较，经部分迷路及岩尖锁孔入路和经全迷路锁孔入路的术野角度、显露的斜坡长度、面神经颅内段长度均有显著增加，但后两种入路的测量值无明显差异。（3）迷路后锁孔入路可保留听力和面神经功能，但对岩斜区的显露有限；部分迷路及岩尖磨除后可广泛显露岩斜区、桥脑小脑角、桥脑前区和海绵窦后部，多角度显露Ⅲ-Ⅺ对脑神经之间的重要结构，且面、听神经功能保有率极高；全迷路磨除后观察角度更多，但进一步增加的显露有限，且需牺牲听力。结论乙状窦前经迷路锁孔入路具有可行性，可良好显露岩斜区等。神经导航可辅助精确完成入路相关的骨质磨除。部分迷路及岩尖或全迷路磨除均可显著增加术野角度和斜坡等重要结构的显露长度，经部分迷路及岩尖锁孔入路可望保留面、听神经功能。     

经翼点入路显微手术切除嗅沟脑膜瘤

目的 介绍一种切除嗅沟脑膜瘤的微创手术方法。方法 采用经翼点入路显微手术切除嗅沟脑膜瘤20例(标准翼点入路6例，翼点锁孔入路14例)，观察肿瘤切除程度和手术效果。结果 全组手术显露良好，肿瘤均全切除(simpson Ⅰ级、Ⅱ级切除)，无额叶脑挫裂伤，仅8例手术输血各400ml，无严重并发症和手术死亡。结论 经翼点入路显微手术是治疗大部分嗅沟脑膜瘤的一种微创方法。     

面神经电位监测显微手术切除听神经瘤16例

2003年1月至2005年5月我们在面神经自发和诱发电位监测下辅以神经内镜，开展枕下乙状窦后锁孔入路切除听神经瘤手术16例，取得了良好的治疗效果。     

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.     

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.     

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.     

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.