大鼠原位肝移植模型的建立及术式改进

目的探讨用双袖套法建立大鼠原位肝移植模型的手术改进方法. 方法在Kamada等的袖套法吻合血管的基础上进行改进,供体改经腹主动脉进行肝脏冷灌注,肝上下腔静脉用缝合法吻合,门静脉和肝下下腔静脉用袖套法吻合,胆总管采用单管内支架胆管端端吻合下进行原位肝移植360例(次). 结果施行大鼠原位肝移植其供体手术时间(31.2±5.0)分钟,供肝修整时间(12.0±3.0)分钟,受体手术时间(45.0±5.5)分钟,无肝期(20.0±2.5)分钟,手术死亡31例,其中出血12例,肝下下腔静脉血栓8例,肝上下腔静脉回流不畅7例,袖套扭转或脱落4例.术后成活2天以上329例,成活率为91.4%.非干预组(非药物治疗组)1周存活率达86.5%. 结论改进的大鼠原位肝移植术操作简便,手术成功率高,可作为肝移植实验可靠、稳定的动物模型.     

120例大鼠原位肝移植报道

目的建立一个稳定的大鼠原位肝移植模型,探讨其术中和术后并发症的预防。方法在Ka-mada“二袖套法”吻合血管的基础上进行改良。供体改经腹主动脉进行肝脏冷灌注;肝上下腔静脉用缝合法吻合,门静脉和肝下下腔静脉用袖套法吻合,胆总管采用单管内支架胆管端端吻合法。结果共施行大鼠原位肝移植120例,手术成功率为96.7%。大鼠1周存活率为95%,3月存活率达90%。结论娴熟细致的外科操作提高了手术成功率,受体无肝期的长短是决定动物存活的关键。     

大鼠原位肝移植模型的手术操作技巧探讨

目的 建立一个稳定的大鼠原位肝移植模型,探讨其手术技巧。方法在Kamada“二袖套法”的基础上进行改良。供体改经腹主动脉进行肝脏冷灌注;肝上下腔静脉用连续缝合法吻合,门静脉和肝下下腔静脉用袖套法吻合．胆总管采用单管内支架胆管端端吻合法。结果共施行大鼠原位肝移植140例,无肝期平均11min．手术成功率为97％,大鼠1周存活率为95％。结论改良的两袖套法具有操作简便、无肝期短、手术成功率高、大鼠术后存活时间长的优点,是大鼠原位肝移植的理想术式。娴熟细致的外科操作、受体无肝期的长短是决定动物存活的关键。     

大鼠原位肝移植胆道并发症的原因分析

目的研究胆道并发症的发生原因,建立稳定的大鼠原位肝移植模型。方法“二袖套法”行大鼠原位肝脏移植180例,即肝上下腔静脉（SVC）采用连续缝合法吻合,门静脉（PV）以及肝下下腔静脉（IVC）采用袖套法吻合,胆总管采用内支架胆管端端吻合法。结果模型稳定后,供肝冷缺血时间为（50．1±12．0）min,无肝期为（16．0±3．1）min,受体手术时间为（54．4±10．6）min,术后胆道并发症的发生率为40％,主要表现为肝脓肿、肝内外胆管扩张、胆泥形成等。结论胆管内支架管的选择以及手术技巧是影响大鼠肝移植术后胆道并发症发生发展的重要因素。     

三袖套法金黄地鼠至大鼠肝移植模型术式改进及并发症预防措施

目的；探讨大鼠原位肝移植法模型的术式改进方法及其并发症的预防措施。方法：应用改良Ｈａｒｉｌａｒａ氏三袖套法－用袖套法吻合肝上下腔静脉（ＳＶＣ），肝下下腔静脉（ＩＶＣ）及门静脉（ＰＶ），应用塑料胆汁引汉支架行胆总管（ＢＤ）或胆囊胆总管吻合法重建胆道连续性，建立金黄地鼠至大鼠原位肝移植模型，结果：成功施行金黄地鼠至大鼠原位肝移植术２１例，其中供肝手术３６例，供体手术，血管袖套准备及受体手术时间分别为５     

大鼠原位肝移植模型的手术技巧及并发症的预防

目的 探讨建立一个稳定的大鼠原位肝移植模型的手术技巧以及术中和术后并发症的预防。方法 在Kamaka用“二袖套法”吻合血管的基础上进行改良。供体改经腹主动脉进行肝脏冷灌注；肝上下腔静脉用缝合法吻合，门静脉和肝下下腔静脉用袖套法吻合，胆总管采用单管内支架胆管端端吻合法。结果 共施行大鼠原位肝移植360次，手术成功率为91．3％。非干预组中，同系移植大鼠1周存活率为86．5％，3个月存活率达80．7％。结论 熟练的显微外科技术、细致的手术操作是预防术中和术后并发症的先决条件。受体无肝期的长短是决定动物存活的关键。     

提高二袖套法大鼠原位肝移植成功率的手术技巧

目的　探讨二袖套法大鼠原位肝移植的手术技巧。方法　在Kamada“二袖套法”基础上进行改良。获取供肝前阻断肝门血供 10min ,再灌注 10min ;分别经腹主动脉和门静脉对肝脏进行双重灌注 ;门静脉和肝下下腔静脉用袖套法吻合 ,肝上下腔静脉用缝合法吻合 ,胆总管采用单管内支架胆管端端吻合法。结果　共施行大鼠原位肝移植 12 0次 ,手术成功率为 90 .8%。平均无肝期为 ( 2 1.0± 3.5 )min ,受体总手术时间为 ( 4 6 .0± 4 .5 )min ,1周生存率为 87.2 %。结论　良好的手术野暴露 ,娴熟的显微外科技术 ,精细的手术操作和配合有助于缩短受体无肝期及总手术时间和提高受体生存率     

豚鼠至大鼠肝移植肝下下腔静脉套管方法的改进

目的探讨豚鼠至大鼠异种原位肝移植中应用改进的肝下下腔静脉套管方法的手术效果。方法豚鼠和SD大鼠各30只分别作为供、受体,并随机配对分为实验组和对照组。实验组采用改进的肝下下腔静脉套管进行肝下下腔静脉袖套管法吻合。对照组采用常规方法进行肝下下腔静脉袖套法吻合。比较两组的供肝切取时间(切、修肝时间)、受体手术时间、无肝期时间、手术成功率、肝下下腔静脉袖套吻合口附近出血发生率以及术后生存时间。结果实验组和对照组的供肝切取时间分别为(32.2±3.5)min、(45.4±5.7)min,修肝时间分别为(14.5±2.1)min、(9.2±1.8)min,切、修肝总时间分别为(46.7±4.8)min、(54.6±6.9)min,比较差异均有统计学意义(均为P0.05)。两组受体的手术时间分别为(52.7±6.1)min、(53.2±6.5)min,无肝期分别为(16.8±2.1)min、(17.2±2.5)min,比较差异没有统计学意义(均为P0.05)。实验组与对照组的手术成功率分别为93%、53%,比较差异有统计学意义(P0.05)。两组的肝下下腔静脉袖套吻合口附近出血发生率分别为0、38%,比较差异有统计学意义(P0.05)。两组手术成功的动物的术后生存时间分别为(115±24)min、(95±29)min,比较差异无统计学意义(P0.05)。结论应用改进的肝下下腔静脉套管方法进行豚鼠至大鼠原位肝移植,手术成功率高,可用于豚鼠至大鼠原位肝移植实验研究模型的制作。     

经升主动脉灌注的无心跳供体大鼠原位肝移植模型的建立

目的 探讨建立一个能灌注更彻底、更易操作、热缺血时间容易控制的原位肝移植动物模型。方法 在Kamada两袖套法的基础上进行改良，供体经升主动脉进行冷灌注，肝上下腔静脉用缝合法吻合，门静脉和肝下下腔静脉用袖套法吻合，胆总管采用胆管内支架端端吻合的方法。建立无心跳供体的大鼠原位肝移植模型。结果 40例移植后1d大鼠存活率为95．0％(38／40)，1周存活率为85．5％(35／40)。结论 经升主动脉灌注的供肝灌注更彻底、均匀，更易操作，热缺血时间控制更精准，行肝移植后1周存活率较文献报道高。     

改良单人操作大鼠原位肝移植模型的建立

目的探索改良传统手术方法单人操作大鼠原位肝移植模型的建立方法。方法 200只(100对)大鼠建立原位肝移植模型,其中80只(40对)进行正式实验,采用改良的Kamada二袖套法,再对手术中关键步骤进行改良,并对术中及术后恢复情况进行分析。结果本组80只大鼠原位肝移植手术均顺利完成。供体手术时间为(28.5±2.4)min,供肝修整时间为(10.2±1.8)min;肝上下腔静脉吻合时间为(15.3±1.9)min,门静脉吻合时间为(3.4±1.2)min,受体无肝期为(23.8±1.9)min,肝下下腔静脉吻合时间为(5.1±2.1)min,胆道重建时间为(3.1±0.9)min。整个手术过程中供、受体出血量均不足0.5 ml。40只受体大鼠,术后2 d成活率为90.0%(36/40),3只死于肝上下腔静脉缝合处出血,1只死于无肝期过长;术后7 d成活率为82.5%(33/40),3只均死于腹腔内感染。结论在单人操作建立大鼠原位肝移植模型中,通过腹主动脉和下腔静脉整块游离行腹主动脉灌注供肝、精细解剖左隔下静脉三角、术中热凝控制出血等方面的改良可减少手术并发症的发生,保证供肝质量,提高大鼠成活率。     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

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.