血管转流管在静脉窦旁脑膜瘤显微全切除手术中的应用

目的：评价血管转流管在静脉窦旁脑膜瘤显微全切除术中的应用价值。方法：2000年2月－2002年3月收治静脉窦旁脑膜瘤18例，其中17例侵犯后2／3矢状窦，1例侵犯先天单侧横窦。术中全部应用血管转流管，在手术显微镜下施行肿瘤切除。结果：全部病例均全部切除肿瘤和受侵犯之窦壁（Simpson I级切除），12例作人造血管移植重建静脉窦，4例行窦壁硬脑膜修补，2例因静脉代偿充分仅单纯结扎静脉窦，术后恢复好，无死亡病例。结论：血管转流管的应用是保证后2／3矢状窦旁及横窦脑膜瘤全切除及顺利进行静脉窦重建的良好技术之一。     

中央回区矢状窦旁脑膜瘤的显微手术治疗

目的 提高中央回区矢状窦旁脑膜瘤的手术效果。方法 应用显微手术治疗中央回区矢状窦旁脑膜瘤20例，术前行DSA检查16例，了解肿瘤的血供、矢状窦通畅程度及瘤周静脉回流代偿情况，采取先阻断窦旁供血，然后囊内或分块切除肿瘤，注意保护中央沟静脉、其他代偿回流静脉及瘤周正常脑组织，妥善处理受累的矢状窦。结果 肿瘤全切除17例，近全切除3例，无手术死亡，术后遗有左侧轻偏瘫1例，双下肢轻瘫2例。13例术后随访3—7年，无肿瘤复发。结论 采用显微手术切除中央回区矢状窦旁脑膜瘤可提高肿瘤全切除率，减少脑重要功能区的损伤，减少并发症，提高患者术后生存质量。     

矢状窦旁脑膜瘤术前明胶海绵栓塞术

矢状窦旁脑膜瘤术前明胶海绵栓塞术蔡浩，易书贵，吴开华，姚雪峰，董元训，赵平，丁家周我院自１９９１年２月～１９９３年５月，对１０例主要由颈外动脉供血的矢状窦旁脑膜瘤，作了术前明胶海绵栓塞术，明显地减少了术中的出血及输血，避免了术中休克的发生，取得了明显...     

多层螺旋CT血管成像三维重建对脑膜瘤血供的评价及应用

目的探讨多层螺旋CT血管成像(MSCTA)对脑膜瘤血供的诊断价值。方法对18例脑膜瘤患者进行MSCTA检查,应用MPR、MIP、SSD和VRT等三维重建技术,对脑膜瘤的血供进行观察。结果18例脑膜瘤中有10例颅内动脉参与供血,有8例脑膜瘤将颅内大血管推移、压迫,但跨过肿瘤段没有直接分支到肿瘤,供血动脉在脑膜瘤内呈放射状分布。静脉分布在肿瘤的表面,回流到附近的浅静脉或静脉窦。结论通过多层螺旋CT扫描及三维重建技术的应用,可以显示脑膜瘤的供血动脉、引流静脉,肿瘤与颅内大血管的关系等,为手术治疗提供重要的信息。     

矢状窦旁脑膜瘤的显微手术治疗

目的 报道矢状窦旁脑膜瘤的显微手术的临床疗效。方法 回顾性总结应用显微手术切除20例矢状窦旁脑膜瘤的临床资料，根据肿瘤大小、位置决定完整或分块切除，妥善处理供血动脉及受累的矢状窦，注意保护中央沟静脉。结果 按Simpson切除分级标准，Ⅰ级切除11例（55％），Ⅱ级切除5例（25％），Ⅲ级切除4例（20％），无手术死亡。结论 显微手术治疗矢状窦旁脑膜瘤是一种安全、有效的方法。     

MSCT诊断成人永存镰状窦6例及文献回顾

目的分析成人永存镰状窦的多排螺旋CT表现,提高对大脑深静脉发育异常的进一步认识。方法选取6例经CTA诊断为永存镰状窦的成人患者,采用MSCT重组技术对其静脉成像进行分析。结果 6例患者均因临床疑诊颅内动脉病变而接受CTA检查。静脉期见大脑大静脉或直窦前部与上矢状窦后2/3相连的条带状血管样结构,未合并其他动静脉异常。结论成人永存镰状窦可不合并其他先天性静脉窦发育异常及阻塞,多排螺旋CTA是其无创、有效的检查方法。     

外伤性颈动脉海绵窦瘘诊断与血管内介入治疗必需遵循的基本原则

外伤性颈动脉海绵窦瘘（traumatic carotid cavernous fistula,TCCF）是因外伤致颅底骨折,损伤了颈内动脉及其分支与海绵窦,其同时受损使颈内动脉或其分支与海绵窦异常沟通所造成的血管病变。因为盗血而产生的缺血与出血为主要临床表现,如搏动性突眼、颅内杂音与眼球运动障碍伴球睑结膜充血、水肿,甚至外翻,有的还伴有颅内出血、鼻衄与脑缺血性损害等症状。根据病史、体检诊断一般不难,CT （CTA）、MRI （MRA）与彩色多普勒超声可以辅助诊断,但诊断的金标准是全脑全程（动脉期、静脉期与静脉窦期）数字减影血管造影（DSA）。通过造影可以了解病变的部位,供血动脉,瘘口部位、大小,有无经海绵前、后间窦使对侧海绵窦显影,盗血与静脉回流情况,并通过对侧颈内动脉与椎动脉造影了解颅内侧支循环情况。     

显微手术治疗矢状窦旁脑膜瘤27例临床分析

目的探讨显微手术治疗矢状窦旁脑膜瘤的效果。方法对术前经影像学检查显示肿瘤位于矢状窦旁的27例患者均行显微手术治疗。结果本组无手术死亡病例。按Simpson切除标准,Ⅰ级切除18例,Ⅱ级切除7例,Ⅲ级切除2例。术后病理诊断为良性脑膜瘤。术后随访6个月~2 a,其中25例恢复正常工作、学习和生活。2例遗留轻微偏瘫,随访期内未出现复发病例,患者均基本恢复正常生活或工作能力。结论显微手术治疗矢状窦旁脑膜瘤不仅肿瘤全切率高,且重要功能区损伤和并发症少,患者术后生存质量恢复好。     

中央区矢状窦旁脑膜瘤的显微手术治疗

目的探讨中央区矢状窦旁脑膜瘤手术的技巧。方法应用显微手术治疗中央区矢状窦旁脑膜瘤32例。利用肿瘤与脑组织之间的蛛网膜界面,囊内或分块切除肿瘤,注意保护中央沟静脉、其他引流静脉和正常脑组织,妥善处理受累的矢状窦。结果SimpsonⅠ级切除17例(53.1%),Ⅱ级切除11例(34.4%),Ⅲ级切除4例(12.5%)。无手术死亡。并发症:脑水肿及梗死2例,予手术减压;10例术后偏瘫加重,其中8例1~6周逐渐恢复,2例一侧肢体不全瘫痪。术后21例随访3个月~5年,2例Ⅱ级切除、2例Ⅲ级切除者术后1~3年复发。结论充分的术前影像学评估,采用显微外科技术切除中央区矢状窦旁脑膜瘤,处理矢状窦,避免脑皮质、中央沟静脉和其他引流静脉的损伤,是提高矢状窦旁脑膜瘤手术全切率和手术疗效的重要因素。     

数字减影全脑血管造影在连头婴显微分离术前及术中的应用

目的 探讨全脑血管造影在连头婴显微分离手术术前和术中的作用。方法 术前在出生后3个月进行股动脉入路脑血管造影，16个月时经股动脉和股静脉入路对双婴颈内动脉，颈外动脉，椎动脉及超选静脉窦内进行造影；术中行脑血管造影监测，判断脑血管情况。结果 术前造影显示双婴连接部颅内动脉无交通，双婴上矢状窦后1/3，窦汇，右婴的左侧横窦起始部融合共用；术中实时脑血管造影对显微分离过程中有关静脉窦的处理进行较好的监测。结论 全脑血管造影是了解连头婴脑血管复杂情况的最佳方法。尤其静脉窦内造影可以充分了解静脉窦变异相融处的解剖和血流动力学变化。术中脑血管造影在静脉窦转流和血管重建手术中有重要的指导意义及监测作用。     

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 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.     

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.     

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.