小脑幕切迹脑膜瘤的显微外科治疗

目的:通过对2 0例小脑幕切迹脑膜瘤显微外科治疗的分析,探讨小脑幕切迹脑膜瘤的显微手术治疗方法。方法:总结2 0例小脑幕切迹脑膜瘤的临床表现、神经影像学特征及显微手术方法和术后处理,肿瘤的体积从3×3×3cm到5×6×7cm。结果:肿瘤切除程度按Simpson分级:Ⅰ、Ⅱ级(根治性全切除) 13例,Ⅲ级6例,Ⅳ级1例。本组术后无死亡,术后脑积水行V -P分流1例,一过性象限盲1例。随访2～6年,无复发。结论:枕下幕上入路及幕下小脑上入路是小脑幕切迹脑膜瘤最常采用的手术入路,该入路对小脑幕切迹区域暴露充分,距离近,手术并发症少。手术者良好的显微外科技术、经验和对小脑幕切迹区域显微解剖的了解,是成功切除该区域肿瘤的关键。     

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。     

影响小脑幕及窦汇区脑膜瘤显微手术全切除的因素

目的：评价影响小脑幕及窦汇区脑膜瘤显微手术全切除的因素。方法：回顾分析经显微手术治疗的小脑幕及窦汇区脑膜瘤23例的临床资料及复述相关文献。结果：手术全切除肿瘤17例,次全切除6例。在次全切除的6例中,4例与颅内大静脉窦受肿瘤侵蚀,且存在静脉回流代偿不完全有关,2例同脑干,血管及脑神经与肿瘤粘连紧密或受肿瘤侵犯有关。结论：影响小脑幕及窦汇区脑膜瘤显微外科手术全切除的主要因素是颅内大静脉窦受侵犯及静脉的回流代偿不完全,肿瘤与脑干和脑神经的紧密粘连。     

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。     

松果体区脑膜瘤及其手术治疗

目的 探讨松果体区脑膜瘤术式的选择并说明影像学检查住处对手术治疗的重要参考价值。方法 回顾９例松果体区脑膜瘤的临床资料及手术体会。结合文献探讨了枕部小脑幕入路和幕下小脑上入路松果树区脑膜瘤切除术的利弊。结果 ９例松果体区脑膜瘤,经仔细阅读ＭＲＩ及ＤＳＡ影像后,其中７例行枕部小脑幕入路切除,２例行幕下小脑上入路切除,术后随讠７个月,患者术前症状均得到明显改善。无明显手术并发症。结论 枕部小脑幕入路是松果体区脑膜瘤比较理想的切除术式,对术前影像学检查所见的肿瘤位、肿瘤相邻重要血管特征及其异常变化住处进行认真分析。是保证松果体区脑膜瘤切除术成功的关键。     

经小脑延髓裂入路显微手术切除儿童第四脑室肿瘤

目的 报道经小脑延髓裂入路显微外科手术切除儿童第四脑室肿瘤的临床疗效。方法 采用枕下正中切口、小脑延髓裂入路在手术显微镜下切除第四脑室肿瘤18例。结果 手术治疗18例，其中肿瘤全切除13例，近全切除5例。术后无l例出现小脑性缄默综合征。出现脑积水3例，2例经行侧脑室．腹腔分流后好转，l例因急性梗阻性脑积水死亡。结论 经小脑延髓裂入路，不需切开小脑蚓部，可避免损伤正常小脑组织，应用显微外科技术有助切除第四脑室肿瘤，提高手术疗效。     

海绵窦区神经鞘瘤的诊断及治疗

目的：探索海绵窦区神经鞘瘤的治疗方法。方法：22例MR确诊为海绵窦区神经鞘 瘤的患者经显微外科手术切除肿瘤,其中经颞-颧入路手术者14例,颞-枕经小脑幕入路手术者8例。结果：22例患者中21例（95.5％）肿瘤全切除,1例肿瘤次全切除。切除的肿瘤组织均经病理证实为神经鞘瘤。术后患者的头痛及突眼症状均有不同程度的减轻;外展神经功能障碍的19例中;12例术后3个月外展神经功能有不同程度的恢复;6例动眼神经麻痹患者,4例术后功能恢复;1例肢体活动障碍者恢复良好;并发脑积水者术后积水减少。所有患者术后均获随访,随访时间8-60个月,未见肿瘤复发。肿瘤次全切除的患者,术后3个月行γ-刀治疗,随访2年未见肿瘤复发。结论：经颞-颧或颞-枕经小脑幕入路行显微手术切除海绵窦区神经鞘瘤,可取得较好的疗效。     

显微外科手术治疗镰幕结合处脑膜瘤

目的 探讨镰幕结合处脑膜瘤的临床特点、影像学表现和显微外科手术注意事项。方法 回顾分析１４例镰幕结合处脑膜瘤患者的临床资料。所有患者术前均进行了ＣＴ检查,１０例患者同时进行了ＤＳＡ检查,６例行ＭＲＩ检查,２例行ＭＲＡ检查。１０例行枕下经小脑幕入路,其中７例为病灶侧向上,３例为病灶侧向下,３／４俯卧位;３例行幕下小脑上入路,１例行侧脑室后部入路。结果 １４例中,肿瘤全切除１２例,近全切除２例。术后发     

矢状窦旁巨大脑膜瘤显微外科切除术

目的报道应用显微外科技术切除矢状窦旁巨大脑膜瘤的方法及临床效果。方法采用矢状窦旁或跨矢状窦手术入路应用显微外科手术结合捆绑牵引方法，完整切除巨大脑膜瘤并注意保护中央沟静脉和上矢状窦通畅。结果手术治疗直径5—10cm以上脑膜瘤26例，其中Ⅰ级切除20例，Ⅱ级切除5例，Ⅲ级切除1例，无手术死亡和特殊并发症发生。24例经1—5年随访，无肿瘤复发。结论应用显微外科技术切除矢状窦旁巨大脑膜瘤能明显提高手术全切率和减少手术出血，缩短手术时间，有效防止矢状窦及中央沟静脉损伤，减少脑组织牵拉，保护重要脑功能区和提高病人术后生存质量。     

显微手术治疗小脑幕切迹脑膜瘤12例分析

小脑幕切迹脑膜瘤指基底位于小脑幕游离缘的脑膜瘤，约占小脑幕脑膜瘤的3％，早期无症状或仅有头痛等非特异性表现．影像学检查肿瘤基底位于小脑幕游离缘和沿游离缘生长的脑膜尾征是其特点。我们白1997年1月至2006年6月收治此类脑膜瘤患者共12例，均行显微手术切除，现报告如下。     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.