保留后瓣及瓣下结构的二尖瓣置换术

目的总结保留后瓣及瓣下结构的二尖瓣置换术(MVR)的临床经验,并观察其与常规MVR比较的临床效果。方法风湿性心瓣膜病患者54例,其中行保留后瓣及瓣下结构的MVR24例(保留二尖瓣后瓣组),行常规MVR30例(常规手术组),观察两组患者术前、术后3个月的左心室舒张期末内径(LVEDD)、左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)等指标。结果保留二尖瓣后瓣组无死亡患者,常规手术组死亡1例;保留二尖瓣后瓣组术后血管活性药物的用量、种类和呼吸机使用时间较常规手术组减少;术后3个月保留二尖瓣后瓣组LVEDD较常规手术组减小,LVEF较常规手术组增大(P<0.05)。结论保留后瓣及瓣下结构的MVR手术操作不复杂,不增加心内手术时间,有可能减少左心室破裂的危险,术中操作仔细可以避免卡瓣,术后心功能恢复较好,更适用于心功能较差、左心室较大的以二尖瓣关闭不全为主的患者。     

保留后瓣及瓣下结构的二尖瓣置换术临床分析

目的总结保留二尖瓣后瓣及瓣下结构二尖瓣置换术(MVR)的经验,评价其临床效果。方法回顾性分析首都医科大学北京安贞医院2006年1月至2011年3月行MVR患者1 035例的临床资料,其中男562例,女473例;年龄37～78(53.84±13.13)岁。风湿性心脏瓣膜病712例,退行性瓣膜病323例;二尖瓣狭窄为主389例,二尖瓣关闭不全为主646例;均排除冠状动脉疾病。不保留后瓣及瓣下结构的MVR(不保留组)457例,保留后瓣及瓣下结构的MVR(保留组)578例,两组患者术前情况差异无统计学意义。分析比较两组患者手术后并发症、死亡率,以及左心室大小与功能。结果不保留组与保留组患者的死亡率(2.63%vs.1.21%,P=0.091)及并发症发生率(8.53%vs.7.44%,P=0.519)差异无统计学意义,但不保留组左心室破裂发生率高于保留组(1.09%vs.0.00%,P=0.012);术后6个月心脏超声心动图提示左心室舒张期末内径(LVEDD)较术前缩小,但两组差异无统计学意义;两组患者左心室射血分数(LVEF)均较术前提高,保留组中二尖瓣关闭不全为主患者的LVEF优于不保留组(56.00%±3.47%vs.53.00%±3.13%,P=0.000),两组二尖瓣狭窄为主的患者中LVEF差异无统计学意义(57.00%±5.58%vs.56.00%±4.79%,P=0.066)。结论保留二尖瓣后瓣及瓣下结构的MVR安全有效,可以减少术后左心室破裂的发生并改善术后心功能。     

二尖瓣置换术保留与不保留瓣下结构对术后早期血流动力学的影响

目的比较常规二尖瓣置换术（ＭＶＲ）与保留瓣下结构的二尖瓣置换术（ＭＶＲＰ）对术后早期血流动力学的影响。方法根据术中是否保留瓣下结构分为３组。Ⅰ组：常规ＭＶＲ，切除全部二尖瓣瓣叶及其瓣下结构；Ⅱ组：保留后瓣及其瓣下组织；Ⅲ组：全部保留二尖瓣装置。术后４小时、２４小时和４８小时分别采用Ｓｗａｎ－Ｇａｎｚ导管测定血流动力学指标：平均肺动脉压（ＭＰＡＰ）、肺毛细血管嵌压（ＰＣＷＰ）、肺血管阻力（ＰＶＲ）、外周血管阻力（ＳＶＲ）、心脏指数（ＣＩ）和左心室每搏作功指数（ＬＶＳＷＩ）。结果术后Ⅰ组ＭＰＡＰ，ＰＶＲ和ＰＣＷＰ均明显高于Ⅱ组和Ⅲ组；而ＣＩ和ＬＶＳＷＩ则低于Ⅱ组和Ⅲ组。结论保留瓣下结构可改善ＭＶＲ术后早期血流动力学，有利于心功能恢复     

保留二尖瓣装置的二尖瓣置换术

目的比较传统二尖瓣置换术(MVR)和保留二尖瓣装置的MVR治疗单纯风湿性二尖瓣狭窄的临床效果. 方法回顾性分析77例单纯风湿性二尖瓣狭窄行MVR患者的临床资料,按术式不同将其分为3组,组1:35例,保留全部二尖瓣装置;组2:19例,保留二尖瓣后瓣瓣下结构;对照组:23例,行传统MVR手术. 结果术后早期对照组和组1各死亡1例,晚期对照组死亡2例,组1和组2各死亡1例.术后3～16个月超声心动图检查显示,对照组和组2左心室舒张期末内径( LVEDD)较术前明显增大(P＜0.01),组1LVEDD 增大不明显(P＞0.01).组1、组2左心室射血分数 (EF)和短轴缩短率(FS)较术前有明显改善(P＜0.01),对照组改善不明显(P＞0.01). 结论单纯风湿性二尖瓣狭窄患者行MVR时保留二尖瓣装置有利于术后左心功能的恢复.     

二尖瓣置换术保留后瓣及瓣下结构28例

目的　了解保留后瓣及瓣下结构对二尖瓣置换术后心功能恢复的影响。方法　 5 2例病人分为两组 ,A组 (对照组 ) 1996年 12月至 1998年 8月共行二尖瓣置换 2 4例 ,切除全部瓣叶及瓣下结构 ;B组 (实验组 ) 1998年 12月至 2 0 0 0年 12月共行二尖瓣置换 2 8例 ,保留全部或大部分后瓣及瓣下结构。术后 1周均用彩色超声多谱勒测定心脏射血指数 (CI) ,每搏量 (SV ) ,射血分数(EF)。结果　B组各项观察指标均优于A组。结论　二尖瓣置换保留全部或大部分后瓣及瓣下结构有利于术后心功能的恢复。     

保留后瓣及瓣下结构的二尖瓣置换术

目的 探讨二尖瓣置换术保留后瓣及瓣下结构对术后左以功能的保护作用。方法 二尖瓣置找术保留后瓣及瓣下结构３５例,其中５例同时行主动脉瓣置换术。术后２周和６个月和超声惊动国图复查,对３５例行保留腱索和民的二尖瓣置换术患者（观察组）与同期未保留后瓣及瓣下结构的二法瓣置换术２０例患者（对照组）的心功能恢复情况进行比较分析。结果 术后２周两组左心室舒张期末径（ＬＶＥＤＤ）、左心室收缩期末径（ＬＶＥＳＤ）、射     

310例保留后瓣的二尖瓣人工瓣置换术的临床分析

目的总结保留二尖瓣后瓣及瓣下结构的二尖瓣置换术的临床效果。方法完成保留二尖瓣后瓣及瓣下结构的二尖瓣置换术310例,男112例,女188例,均为风湿性心脏病。术前心功能分级(NYHA)I级33例,II级119例,III级126例,IV级32例。结果术后死亡2例,随访6个月~6年,无死亡病例,心功能I-Ⅱ级。结论保留二尖瓣后瓣及瓣下结构二尖瓣置换术可减少左心室破裂的危险,改善术后心功能。     

部份或完全保留瓣下结构的二尖瓣替换术后早期效果比较观察

为提高二尖瓣置换术的疗效，作者对部分保留瓣下结构的二尖瓣置换术（ＭＶＲ）２１例、完全保留瓣下结构２０例，分别与同期完全切除瓣叶和瓣下结构者２６例比较。结果表明，部分或全部保留瓣下结构者术后病情较平稳，较少需要血管活性药物，左房内径缩小较多，不易发生左心室破裂；与另两组相比，完全保留组术后早期左心室缩小更明显，术后住院时间也较短。作者建议尽可能部分保留瓣下结构，尤推荐完全保留瓣叶和瓣下结构，二尖瓣口内置入人工瓣即所谓瓣中瓣ＭＶＲ。     

乳头肌瓣环固定后的二尖瓣置换术

目的　为了提高二尖瓣置换术的疗效和远期效果 ,总结保留二尖瓣瓣下结构以维持动力环完整性的经验。　方法　 2 0 0 0年 1月至 2 0 0 2年 2月 ,对 130例心瓣膜置换术患者采用将乳头肌缝合固定于瓣环下的方法 ,并根据二尖瓣主要病变类型将其分为 3组 :二尖瓣关闭不全组 (MI组 )、二尖瓣狭窄组 (MS组 )、主动脉瓣和二尖瓣双瓣膜置换术组 (DVR组 )。术后用二维超声心动图测量升主动脉内径 (AD)、右心室舒张期内径 (RVIDd)、右心房内径(RAD)、左心室舒张期内径 (L VIDd)、左心房内径 (L AD) ,比较各组手术前后的效果。　结果　 MI组术后 L VIDd、L AD均较术前明显缩小 (P<0 .0 1) ,RAD与术前比较无明显变化 ;DVR组 RAD、L VIDd、L AD明显缩小 (P<0 .0 1) ;MS组 RVIDd、L AD明显缩小 (P<0 .0 1) ,L VIDd较术前无明显变化。全组住院死亡 1例 ;随访 12 9例 ,死亡 3例 ,其余12 6例术后心功能达 级和 级。　结论　二尖瓣置换术时 ,将左心室乳头肌固定于瓣环下 ,可保持乳头肌瓣环的连续性 ,最大程度地改善心瓣膜置换术后心脏功能。     

二尖瓣替换术保留瓣叶及瓣下结构37例

二尖瓣替换术保留瓣叶及瓣下结构３７例梁智星，李大奇，孙长恩，高南翔，郭建军，梁法禹行二尖瓣替换术时保留瓣叶和瓣下结构对维护左室张力环、维持心肌收缩功能和防止左心室破裂有重要作用［１～３］。我们自１９９０年１２月至１９９２年１０月连续行保留瓣叶及瓣下结...     

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.     

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.     

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.