蝶骨嵴内侧大型脑膜瘤的显微手术切除

目的 探讨蝶骨嵴内侧大型脑膜瘤的显微外科治疗方法。方法 回顾性分析28例蝶骨嵴内侧大型脑膜瘤显微外科手术。结果 21例达SimpsonⅠ、Ⅱ级切除，7例达Simpson Ⅲ级切除。术后偏瘫4例，植物生存2例，无死亡。结论 改良的翼点入路适于切除蝶骨嵴内侧大型脑膜瘤，掌握处理侵犯视神经、颈内动脉及海绵窦的手术技巧是提高肿瘤全切率的关键，但是对于明显侵犯颈内动脉、海绵窦等重要结构的肿瘤尚应考虑姑息的手术方式。     

大型及中型复发性蝶骨嵴脑膜瘤的显微手术切除

目的：介绍应用显微手术切除大型及中型复发性蝶骨嵴脑膜瘤的经验及探讨复发的原因。方法：回顾分析24例大型及中型复发性蝶骨嵴脑膜瘤经额颞眶颧联合入路显微手术治疗的资料。结果：手术全切除(SinpsonⅡ级)14例，次全切除6例，大部分切除4例，其中肿瘤周边脑内嵌有孤立瘤结节5例。结论：经额颞眶颧联合入路与应用显微手术有助于对大型及中型复性蝶骨嵴离膜瘤的全切除。手术切除不全、术中肿瘤种植是蝶骨嵴脑膜瘤复发的原因。     

神经内镜辅助眶上锁孔入路治疗巨大嗅沟脑膜瘤

目的探讨神经内镜辅助眶上锁孔入路治疗巨大嗅沟脑膜瘤的手术效果及手术技巧。方法采用内镜辅助、眶上锁孔入路（显微手术）治疗12例巨大（≥7cm）嗅沟脑膜瘤。结果肿瘤全切除9例（SimpsonⅠ级切除5例，Ⅱ级切除4例），次全切除（SimpsonⅢ级切除）3例。无手术死亡。10例随访3个月～2年，平均14个月。9例恢复正常生活，1例生活能自理。NRI随访9例，肿瘤无复发。结论利用神经内镜辅助及显微外科技术，采用眶上锁孔入路、对肿瘤进行分块切除治疗巨大嗅沟脑膜瘤，手术创伤小，疗效满意。     

枕大孔区脑膜瘤的显微手术治疗

目的报道枕大孔区脑膜瘤的显微神经外科手术的临床结果。方法选择经枕大孔后缘入路包括枕髁远外侧入路、枕下后正中入路和枕下下外侧入路，应用显微外科手术治疗的枕大孔区脑膜瘤7例，并结合文献分析影响枕大孔区脑膜瘤的手术入路的选择和影响预后的因素。结果肿瘤最大直径为0．8～4．8cm，肿瘤瘤体位置位于脑干前方3例，侧方2例，后方2例。经枕髁远外侧入路2例，枕下后正中入路3例，枕下外侧入路2例，肿瘤手术全切除6例（Simpson Ⅰ级4例，Simpson Ⅱ级2例），次全切除1例。术后6例随访6～36个月，神经系统占位症状较术前明显好转，未见肿瘤残留和复发。结论选择合适的经枕大孔后缘的手术入路，应用显微外科手术治疗枕大孔区脑膜瘤可获得较好的临床效果。     

蝶骨翼脑膜瘤81例临床回顾分析

目的 总结蝶骨翼脑膜瘤的诊断、分型及手术治疗的经验和体会。方法 回顾性分析了经显微手术和病理证实的蝶骨翼脑膜瘤81例，其中内侧型43例，外侧型36例，扁平型2例，巨大型7例，大型63例，小型11例。采用改良翼点入路53例；额下翼点联合入路7例；经颧弓翼点入路15例；额颢眶颧入路6例。结果 Simpson Ⅰ级切除45例，Ⅱ级切除17例，Ⅲa级切除9例，Ⅲb级6例，Ⅳa级3例。术后本组患者颅高压、视力下降及眼球突出等临床症状均有不同程度的改善和恢复。术后随访9个月～6年，复发5例，3例行二次于术。结论 充分全面的术前评估，正确选择手术入路，熟练掌握术区显微解剖及显微手术操作，可以提高肿瘤全切率，减少术后并发症，以降低术后致残率和复发率。     

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。     

眶上微骨窗入路显微手术切除鞍上脑膜瘤

目的 介绍经眶上微骨窗入路切除鞍上脑膜瘤的显微外科技术和经验.方法 经眉内小切口5例,经翼点入路16例,采用眶上约3.5 cm×2.5 cm小骨窗开颅,显微外科技术切除鞍上脑膜瘤21例,肿瘤最大径2.8～6.2 cm,回顾分析其临床资料.结果 所有肿瘤显露良好,Simpson Ⅰ级切除5例,Simpson Ⅱ级切除15例,Simpson Ⅲ级切除1例.无手术死亡及严重并发症,术前视力障碍患者术后均有不同程度改善.术后随访6个月至5年,平均3.8年,影像学上肿瘤残留1例.结论 眶上微骨窗入路可替代传统额下或翼点入路切除鞍上脑膜瘤并具有手术创伤小、术后恢复快等优点.     

前床突脑膜瘤的显微外科治疗

目的 探讨前床突脑膜瘤的分型和疗效。方法 回顾性分析11例前床突脑膜瘤的临床表现、分型、手术及其效果。结果 本组肿瘤全切除（Simpson Ⅱ级）8例（72、7％），近全切除（Simpson Ⅲ级）3例（27、3％），死亡4例（36．4％），预后良好5例（45．5％）。结论 ①前床突脑膜瘤可被分为鞍前型、鞍旁-鞍上型和广泛型，各型又可以根据是否侵袭或包裹海绵窦或颈内动脉分为A、B两个亚型。②前床突脑膜瘤的全切除应采取谨慎的积极态度，肿瘤侵袭海绵窦或颈内动脉是影响肿瘤切除程度和手术效果的关键因素，对于侵袭或直接附着于海绵窦或颈内动脉壁的瘤组织不应勉强切除，残余肿瘤可行立体定向放射外科治疗或密切随访。     

12例内侧型蝶骨嵴脑膜瘤显微手术治疗体会

目的:提高内侧型蝶骨嵴脑膜瘤的手术全切率、降低死亡率和致残率。方法:本文对12例内侧型蝶骨嵴脑膜瘤的手术治疗作回顾性分析。结果:实现肿瘤镜下全切8例,大部分切除4例,无手术死亡,疗效满意。结论:宜采用翼点入路在显微镜下切除,少数可结合术前超选栓塞颈外动脉系统的肿瘤供应支,术中注意保护周围重要神经血管,可提高肿瘤全切率,降低死亡率。但对明显侵犯下丘脑、海绵窦等重要结构的肿瘤,手术难度较大者,尚应考虑姑息的手术方式。     

神经内镜辅助眶上锁孔入路切除鞍结节脑膜瘤

目的总结内镜辅助下经眶上锁孔入路显微手术切除鞍结节脑膜瘤的手术效果。方法13例鞍结节脑膜瘤采用眶上锁孔入路,先在显微镜直视下切除部分肿瘤,再在内镜辅助下切除残余肿瘤。结果肿瘤全切除12例（SimpsonⅠ级切除2例,Ⅱ级切除10例）,次全切除1例（SimpsonⅢ级切除）。11例术后随访3个月～6年,平均2.3年,〈1年恢复正常工作和生活9例,术后2年肿瘤复发1例,1年后恢复生活自理1例。结论内镜辅助下眶上锁孔入路切除鞍结节脑膜瘤克服了显微镜直视下的盲区,并发症少,创伤小,效果满意。     

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.