膀胱全切原位W形回肠代膀胱术120例临床分析

目的 探讨膀胱全切原位W形回肠代膀胱术优缺点。方法120例男性膀胱癌患者,其中浸润性膀胱移行细胞癌99例,移行细胞癌伴部分鳞化8例,移行细胞癌伴腺癌及鳞癌3例,腺癌6例,鳞癌4例,均行膀胱全切原位W形回肠代膀胱术。膀胱全切采用顺行、逆行相结合的方法。截取末段回肠,排列成W形,褥式缝合制作储尿袋。输尿管以乳头法包埋术种植。结果手术时间,前50例为210-300mim,平均270min;后70例为110-205min,平均143min。术后9l例获得随访,随访2—88个月,平均30个月,85例白天可控制排尿,其中71例夜间可控制排尿。9例术后发生输尿管扩张,7例合并轻度肾积水,2例合并中度肾积水,2例肾功能轻度异常。45例行膀胱造影仅1例发生右侧输尿管返流。术后3个月复查出现低血钾者6例,余85例血电解质均在正常范围。20例患者行尿动力检查,尿流曲线呈持续型12例,间歇型8例;膀胱尿道造影显示尿流持续型代膀胱颈口呈漏斗形,排尿时开放良好,而尿流间歇形代膀胱颈口不呈漏斗形或排尿时颈口开放欠佳。结论膀胱全切原位W形回肠代膀胱术手术时间短,操作简单,出血少,并发症少,原位W形回肠代膀胱有较好的储尿和排尿功能,电解质紊乱发生率低。     

改良W形回肠代膀胱术的疗效观察(附36例报告)

目的 :探讨改良W形回肠代膀胱术的疗效。方法 :对 36例膀胱肿瘤患者行根治性膀胱切除、W形回肠代膀胱术 ,并对术式进行改进。结果 :36例手术时间平均 4 .2h。术后 31例随访 4～ 19个月 ,平均 10 .6个月 ,无严重并发症 ,均无瘤生存。患者一般于术后 3周自主可控性排尿 ,日间尿控率为 10 0 % ,术后 3、6、12个月夜间尿失禁发生率分别为 2 2 .5 %、11.1%及 6 .2 %。术后 6个月尿动力学检查膀胱容量 (36 0± 30 )ml,最大尿流率 (13.6± 2 .6 )ml/s,剩余尿量 (11.5± 5 .8)ml,充盈期膀胱压力明显低于尿道闭合压。新膀胱造影发现新膀胱呈球形 ,完全位于盆腔 ,未见输尿管反流。B超及IVU检查发现原上尿路积水 4例均明显减轻 ,其余未发现输尿管狭窄和上尿路积水征象。无高氯性酸中毒 ,肾功能正常。结论 :改良W形回肠代膀胱术手术时间短 ,操作简单 ,创伤轻 ,并发症少 ;新膀胱容量大 ,内压低 ,顺应性好 ,功能接近于正常膀胱 ,保持原位排尿 ,明显提高了患者术后生活质量 ,值得临床推广应用。     

回肠正位代膀胱的尿动力学检测

目的：从尿动力学角度阐明回肠代膀胱的尿动力学特点，并为该术式提供动力学依据。方法：对1991年6月-1998年9月间作回肠代膀胱术26例患者用Dantec-Menuet尿动力仪行尿流率，代膀胱压力。容积和尿道压等检查。结果：最大尿流率为16.4(5.0-28.0)ml/s。代膀胱的最大容积为424.5(240-803)ml。贮尿囊最大内压为2.695(2.060-4.606)kPa。排尿时贮尿囊内压为7.918(4.508-10.486)kPa。最大尿道闭合压为6.292(4.900-7.742)kPa。结论：回肠代膀胱具有较大的容积。能满足贮尿功能，有足够大的尿道压和较低的膀胱压，保证了可控性，排尿期膀胱压远大于尿道压，为原位排尿提供了保障，是一种理想的膀胱替代术。     

原位回肠新膀胱术15 例临床报告

目的 探讨膀胱全切除术后原位M形回肠新膀胱的疗效.方法 膀胱恶性肿瘤患者15例行膀胱全切除术,采用M形原位回肠新膀胱术进行尿流改道.结果 围手术期无1例死亡,随访3-20个月(平均12.4个月).膀胱容量(340±23.71)mL(210-430 mL),膀胱充盈压为(20.12±0.64)cmH2O(13.50-33.91 cmH2O),排尿膀胱压为(77.02±12.11)cmH2O(53.21-87.09 cmH2O),残余尿(15.43±34.33)mL(3-88 mL),最大尿流率(18.16±5.60)mL/s(11.38-19.17 mL/s).无明显输尿管梗阻及返流.未发现尿道残端复发肿瘤.无排尿困难者,白天均可控制排尿;术后大于6个月者无夜间遗尿,术后半年15例复查B 超无肾积水表现,复查生化指标,肾功能电解质在正常范围内,1例术前肾积水及肾功能异常者术后为正常.结论 原位回肠新膀胱术是较理想的膀胱全切术后的尿流改道方式.     

糖尿病膀胱尿动力学及逼尿肌功能改变的相关性研究

目的探讨糖尿病膀胱尿动力学变化与逼尿肌功能改变之间的相关性。方法回顾性分析70例糖尿病患者尿动力学检查结果,将患者分为早期组(病史<8年〉和进展期组(病史>12年),分别测定初尿意的膀胱容量、最大膀胱容量、最大自由尿流率、PQmax、剩余尿量。并结合2型糖尿病(T2DM)大鼠与正常大鼠的离体逼尿肌肌条实验,分析实验鼠发病6周和18周的逼尿肌兴奋性、最大收缩力和平均收缩力变化。结果临床资料显示29例(41%)表现为低顺应性膀胱,28例(40%)膀胱感觉减退,30例(43%)排尿期逼尿肌压力减退,22例(31%)剩余尿量超过150ml,10例(14%)逼尿肌不稳定,6例(9%)不能自行排尿。患者膀胱灌注过程中产生初尿意的灌注容量(203.25±107.53)ml(125~630ml),最大膀胱容量(428.09±227.89)ml(220~1350ml)。最大自由尿流率(10.70±3.27)ml/min,剩余尿量(100.57±108.08)ml,早期组患者产生初尿意的膀胱容量增加为(151.67±24.07)ml,进展期患者初尿意的膀胱容量增加为(268.16±13.90)ml,最大膀胱容量(592.97±252.51)ml,最大自由尿流率(8.61±2.04)ml/min,PQmax(33.16±19.81)cmH2O(1cmH2O=0.098kPa),剩余尿增加至(169.03±137.25)ml。动物实验发现T2DM大鼠逼尿肌的张力阈值为(0.72±0.33)g,显著高于对照组(0.32±0.18)g,F=59.63,P<0.0001;最大逼尿肌收缩力T2DM组(0.08±0.04)g,较对照组(0.11±0.05)g降低(F=7.47,P<0.01);平均收缩力T2DM组(0.06±0.02)g,较对照组(0.07±0.03)g明显降低(F=5.71,P<0.05)。随着实验动物发病时间延长,T2DM大鼠逼尿肌张力阈值呈现增高趋势,而逼尿肌最大及平均收缩力均降低。结论根据临床及动物实验结果推测,早期糖尿病患者膀胱感觉减退可能是逼尿肌兴奋性降低的缘故。进展期膀胱感觉进一步减退、最大膀胱容量显著增大、最大自由尿流率降低、排尿期最大尿流时的逼尿肌压力降低、剩余尿量显著增多等一系列尿动力学改变,可能是在逼尿肌兴奋性改变的基础上出现逼尿肌收缩力降低的结果。     

球形可控性回肠代膀胱术(附26例报告)

目的　探讨球形可控性回肠贮尿袋代膀胱术的临床疗效。　方法　对 2 6例膀胱移行细胞癌患者采用末段回肠制成球形贮尿袋代膀胱的原位膀胱重建术。　结果　 2 6例手术顺利 ,术后随访 3～ 36个月 ,平均 2 1个月。全组无严重并发症 ,健康存活 2 5例 ,1例术后 17个月死于脑溢血。排尿可控率 10 0 %。术后 12个月 2 0例平均尿量 5 85ml/次 ,剩余尿量 2 2ml,最大尿流率 17.3ml/s。膀胱测压 18例 ,平均半充盈、充盈和排尿压力分别为 12、17和 5 3cmH2 O(1cmH2 O =0 .0 98kPa)。病理切片示新膀胱粘膜变薄 ,粘膜腺体减少 ,绒毛消失 ,部分区域固有膜腺体消失 ,呈鳞状化生结构。PAS染色阳性、热休克蛋白 (HSP)阳性 ,p5 3基因表达阴性。　结论　球形可控性回肠贮尿袋代膀胱术具有容量大、压力低、可控性好 ,对机体干扰轻、并发症少等优点 ,是原位膀胱重建的良好术式。     

三种正位新膀胱术后膀胱功能的临床观察

目的评价3种正位新膀胱术式患者术后膀胱功能。方法胃代膀胱术后患者38例、回肠代膀胱术后31例、乙状结肠代膀胱术后33例,术后1～3个月随访患者排尿状况、上尿路B超、肾图或IVU检查、尿动力学检查,统计学分析比较各组疗效。结果胃代膀胱术后排尿通畅性较好,最大尿流率（17．2±6．2）ml/s,尿路感染发生率5％,膀胱容量（230±56）ml、尿失禁26％、遗尿21％；回肠代膀胱术和乙状结肠代膀胱术后膀胱容量分别为（320±70）ml、（300±60）ml,尿失禁分别为6％、9％,遗尿分别为6％、9％；上尿路梗阻和返流发生率均较低,与胃代膀胱术比较差异有统计学意义（P＜0．05）。结论3种代膀胱术术后膀胱贮尿功能良好,以回肠代膀胱术和乙状结肠代膀胱术后功能更好,胃代膀胱术由于其胃壁的生理特点在新膀胱抗感染和排尿功能方面满意。     

非神经源性膀胱外括约肌协同失调症误诊为慢性非细菌性前列腺炎23例分析

目的 :研究非神经源性膀胱外括约肌协同失调症 (NNDSD)作为误诊为慢性非细菌性前列腺炎患者的排尿功能障碍的病因。方法 :对 2 3例经尿动力学证实的伴有慢性排尿功能障碍的NNDSD进行回顾性分析。结果 :症状持续时间 10～ 89月 (平均 3 8.6月 ) ,抗生素使用时间 43～ 15 6d(平均 64 .6d)。平均美国泌尿外科学协会 (AUA)症状评分是17.5± 3 .7,最大尿流率 13 .3± 4.2ml/s ,最大尿流率时逼尿肌压 5 8.3± 10 .7cmH2O ,最大尿道压 12 6.4± 10 .5cmH2O。结论 :一些误诊为慢性非细菌性前列腺炎并行经验性治疗的患者实际上是功能性膀胱出口梗阻。尿动力学检查有助于NNDSD的正确诊断。     

腹腔镜下膀胱全切除、原位回肠新膀胱的尿流动力学分析

目的 探讨腹腔镜膀胱全切除、原位回肠新膀胱的临床效果。方法 对8例行腹腔镜膀胱全切除、原位回肠新膀胱患者进行排尿情况的记录和尿动力学检查。结果 8例患者均可自主控制排尿（1例夜间轻微尿失禁），在新膀胱充盈过程中均可出现胀痛感觉，膀胱平均容量377．5ml，压力17．9cmH2O，最大尿流率18．1ml／s，最大尿道闭合压68．5cnH2O，功能性尿道长度3．7cm。结论 腹腔镜根治性全膀胱切除、原位回肠新膀胱术较传统的开放手术创伤更小，但贮尿囊一样具有容积较大、内压较低和可控性较好的优点，排尿良好，值得临床推广。     

体外可控性回肠膀胱术的实验研究及临床应用

目的　提高体外可控性回肠膀胱术的治疗效果。　方法　距回盲部约 2 0cm处切取一段回肠 ,中间部分折叠成N形并缝制成贮尿囊 ;近端回肠为输入道 ,近贮尿囊 4～ 5cm回肠纵形折叠缝合以缩窄管腔 ;远端 8～ 10cm回肠从腹壁造瘘口处穿出体外 ,于造瘘口处取双片梯形皮瓣包绕外露肠管缝制成皮管 ,构建输出道。将尿液控制器置于皮管外 ,利用气囊控制排尿。 12只犬应用研究后对 5例膀胱癌患者采用此术式治疗。　结果　 10只犬手术顺利 ,术后 3个月时贮尿囊平均最大容量 (15 0± 4 0 )ml,最大充盈压 (2 4 .4± 5 .3)cmH2 O。 5例患者术后随访 3～ 14个月。术后 3个月时贮尿囊平均最大容量 (2 90± 80 )ml,最大充盈压 (36 .3± 8.2 )cmH2 O ,最大尿流率 (2 0 .3± 4 .7)ml/s ,无剩余尿。影像学检查肾脏显影良好 ,输尿管通畅。尿液控制器气囊充气后无尿液流出 ,气囊消气后尿线粗。　结论　该尿流改道术式可达到体外控尿效果 ,不必佩戴集尿袋及导尿 ,手术操作比较简单、并发症少。     

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.     

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.     

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.     

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.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). Methods: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre-and intra-operative arterial blood gases and O₂ flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg^?1· h^?1 vs. 6.6 ± 4.8 μg · kg^?1· h^?1), a lower O₂ supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd?/procedure). Intraoperative PaCO₂ was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.