上颈椎术后颈椎矢状位参数变化及影响因素

目的:分析寰枢椎脱位患者上颈椎术后颈椎矢状位参数变化及影响因素。方法:对2011年3月至2022年7月行上颈椎手术的15例寰枢椎脱位患者进行回顾性分析,统计所有患者的基本信息及术前与末次随访的矢状位参数,包括枕颈角(C0-C2 Cobb角)、下颈椎曲度(C2-C7 Cobb角)、T1倾斜角、颈椎矢状面轴向垂直距离(C2-C7 SVA),并进行统计学分析。结果:末次随访时患者的C2-C7 Cobb角为15.18°±12.41°,小于术前的24.30°±15.57°;末次随访时患者的T1倾斜角为28.09°±15.20°,大于术前的24.14°±15.59°,差异均有统计学意义(P均<0.05)。末次随访时患者C0-C2 Cobb角和C2-C7 SVA增大,但与术前相比差异无统计学意义(P均>0.05)。ΔC2-C7 Cobb角与术前C2-C7 Cobb角的大小有关,差异有统计学意义(P<0.05)。术前C2-C7 Cobb角>20°的患者术后均出现不同程度的下颈椎曲度减小。结论:接受上颈椎手术的寰枢椎脱位患者术后可能出现下颈椎曲度减小,术后下颈椎曲度的丢失与术前C...     

寰枢椎脱位行寰枢椎后路融合手术后的下颈椎曲度变化情况及其预测因素

目的 探讨寰枢椎脱位(atlantoaxial dislocation,AAD)患者行寰枢椎后路融合手术后的下颈椎曲度变化情况,并分析其潜在的预测因素.方法 纳入本院自2012年1月～2019年3月采用寰枢椎后路固定融合手术治疗的31例AAD患者作为研究对象,统计所有患者的性别、年龄和手术前后的下颈椎曲度(C2-C7角)、其他颈椎矢状面参数[包括:枕颈角(C0-C2角),C1-C2角,颈椎前凸角(C0-C7角),颈椎矢状面轴向垂直距离(C2-C7 sagittal vertical axis,C2-C7 SVA),T1倾斜角(T1 slope,T1 S),颈部倾斜角(neck tilt,NT)和胸廓入口角(thoracic inlet angle,TIA)]变化情况.随访观察术后C2-C7角变化情况,若有所减小,则视为下颈椎曲度减小(A组);若有所增加或不变者,纳入B组.对两组患者性别、年龄等人口学资料,以及手术前后的相关颈椎矢状位参数进行单因素分析;并以二分类Logistic回归分析对相关因素进行多因素分析.结果 31例AAD患者均顺利完成后路寰枢椎固定融合术,术后获访9～15个月、平均(12.1±2.8)个月,术后出现下颈椎曲度减小者9(29.03％)例.单因素分析显示,术前C2-C7角、术后C1-C2角存在统计学意义(P<0.05).多因素Logistic回归分析显示,术前C2-C7角≥20°(OR=8.276,P=0.001)和术后C1-C2角≥20°(OR=6.754,P=0.013),均是AAD患者术后下颈椎曲度减小的独立预测因素.结论 下颈椎曲度减小在AAD患者行寰枢椎后路固定融合手术后并不少见,术前C2-C7角≥20°、术后C1-C2角≥20°可增加其发生风险.     

寰枢椎后路融合角度与下位颈椎曲度的相关性研究

目的 评价寰枢椎后路融合角度与术后下位颈椎矢状面曲度之间的联系并确定最佳的寰枢椎固定角度以保护颈椎生理曲度.方法 对1995年2月至2005年6月因寰枢椎脱位而行后路C1,C2融合术的92例患者进行术后随访.术前测量颈椎侧位片C1-C2,C2-C7夹角,并且进行术后长期随访,以观察术后随访C1-C2,C2-C7夹角之间的相关性. 结果所有患者均获得随访,时间2.0～10.3年,平均5.2年.术前及术后随访时C1-C2夹角平均值分别为18.4°±9.3°、26.0°±6.8°,差异有统计学意义(t=10.4,P<0.05);术前及术后随访时C2-C7夹角平均值分别为14.5°±10.1°、5.6°±12.0°,差异有统计学意义(t=6.0,P<0.05);其中术后随访C1-C2固定角度<20°(10°～20°)共计30例,≥20°(20.0°～43.6°)共计62例.C1-C2固定角度<20°者,术后随访C1-C2角度与C2-C7夹角之间无明确的相关性;C1-C2固定角度≥20°者,术后随访C1-C2角度与C2-C7夹角之间存在线性负相关;C1-C2术前、术后随访夹角的变化值与C2-C7术前、术后随访夹角的变化值之间也存在线性负相关. 结论寰枢关节行后路手术固定于高度前凸位时将导致术后下位颈椎的脊柱后凸,并且固定角度越大,下位颈椎的后凸程度就越大;为了保持下位颈椎的生理性曲度,手术中应尽量将C1-C2固定的角度控制在10°～20吨围内.     

强直性脊柱炎合并寰枢椎脱位的影像学特点及手术疗效

目的 :分析强直性脊柱炎(ankylosing spondylitis,AS)合并寰枢椎脱位(atlantoaxial subluxation,AAS)的影像学特点,评估手术治疗的临床疗效。方法:回顾性分析2001年11月～2019年2月于我院接受颈枕融合或上颈椎融合术治疗的AS合并AAS的患者资料8例,均为男性,年龄15～59岁,平均39.9±16.2岁。术前颈椎侧位X线片示所有患者均存在寰枢椎脱位,寰齿前间隙(anterior atlantodental interval,AADI)平均为10.4±7.0mm(2～17mm);其中5例为前脱位,AADI平均为15.2±2.7mm(11～17mm),另3例为后脱位合并齿状突骨折。3例患者术前伴不全瘫(Frankel D级2例,Frankel C级1例)。在术前、术后即刻及末次随访的颈椎侧位X线片上测量C0-C2角、C1-C2角、C2-C7角、C2-C7矢状面偏移(sagittal vertical axis,SVA)和AADI。采用Frankel分级评估术前及术后出院前的神经功能状态。应用配对样本t检验比较术前、术后影像学参数。记录手术并发症情况。结果:7例获得随访,随访时间3～96个月,平均37.9±38.5个月。C0-C2角术前为18.9°±16.8°,术后改善至22.6°±15.4°,末次随访时为20.4°±11.4°;C1-C2角术前为19.6°±18.7°,术后改善至28.5°±10.1°,末次随访时为24.6°±8.1°;术前C2-C7角平均为-6.4°±25.2°,术后改善至6.6°±19.7°,末次随访时为9.0°±18.8°;C2-C7 SVA术前为46.0±36.5mm,术后改善至39.4±26.4mm,末次随访时为39.6±18.9mm,C0-C2角、C1-C2角、C2-C7角及C2-C7 SVA术前、术后的差异均无统计学意义(P0.05)。AADI术前为10.4±7.0mm,术后显著改善至6.4±4.1mm(P0.05),差异具有统计学意义,末次随访时为6.9±4.6mm。3例术前不全性瘫痪者,术后神经功能均有一定程度的恢复,其中2例术前Frankel D级者恢复至E级;另1例由术前Frankel C级改善至D级。所有患者均未发生神经并发症及浅表、深部感染,且无断钉、断棒、螺钉松动等内固定并发症发生。结论:AS合并AAS在影像学上多表现为前脱位,手术治疗AS合并AAS可取得良好的疗效。术前伴神经损害者需行后路C1后弓切除减压。后路颈椎/颈胸段截骨矫形适用于明显颈椎/颈胸段后凸畸形患者。     

无症状成人颈椎矢状位曲度分析及其与全脊柱矢状位参数的关系

目的:探讨正常亚洲黄种人群颈椎矢状位曲度及其与全脊柱矢状位参数的关系。方法:采用影像学分析对132名成人无症状志愿者进行研究,所有志愿者行全脊柱正、侧位X线检查及中立位颈椎侧位片,测量颈椎矢状位参数包括C0-C2角(Occiput-C2 angle)、C2-C7角(C2-C7 angle)、C2-C7矢状面轴向距离(sagittal vertical axis,SVA)、头部重心(center gravity of head,CGH)~C7 SVA(CGH-C7 SVA)、C2-CGH SVA,和胸椎矢状位参数:T1倾斜角(T1 slope)、胸椎后凸角(thoracic kyphosis,TK),脊柱-骨盆的方向性参数:腰椎前凸角(lumbar lordosis,LL)、骨盆入射角(pelvic incidence,PI)、骶骨倾斜角(sacral slope,SS)及全脊柱矢状位参数:脊柱骶骨角(spinal sacral angle,SSA)、C7-S1的矢状面轴向距离(C7-S1 SVA)。使用Toyama等颈椎矢状位序列分型方法将所有志愿者分为三组:前凸组,后凸组,变直或鹅颈畸形组,并比较三组人群各参数间差异。使用皮尔逊相关分析和单因素ANOVA分析相关数据。结果:C0-C2角的平均值是15.13°±6.69°,C2-C7角的平均值是12.03°±7.64°。C2-C7 SVA平均值是18.67±7.96mm,CGH-C7 SVA的平均值是22.95±12.18mm,CGH-C2 SVA的平均值是7.08±5.38mm,T1 slope平均值是26.33°±7.01°。三组志愿者中,前凸组共43名(占32.6%),变直或鹅颈畸形组共74名(占56.1%),后凸组15名(占113%)。C2-C7角与T1 slope(r=0.422)相关,T1 slope与TK(r=0.434)、TK与LL(r=0.574),LL与SS(r=0.459),SS与PI(r=0.727)相关。三种志愿者中C2-C7角,CGH-C7SVA,Tl slope,TK在三组间两两比较均有显著统计学差异。结论:部分无症状成人亦存在颈椎的变直或鹅颈畸形甚至后凸改变。颈椎后凸表现可能更多的是一个局部问题而非整体脊柱骨盆参数异常。     

颈椎后纵韧带骨化症单开门椎管扩大成形术后颈椎矢状位参数变化与疗效的关系

目的 :探讨颈椎后纵韧带骨化症(OPLL)患者行颈后路单开门椎管扩大成形术后颈椎矢状位参数变化与手术疗效的关系。方法:选取2009年1月~2013年1月在我院接受颈后路单开门椎管扩大成形术的OPLL患者68例,随访12~30个月。记录手术前后JOA(Japanese Orthopaedic Association)评分、颈肩臂疼痛VAS(visual analog scale)评分,计算神经功能JOA改善率(improvement rate,IR)。术前、术后和随访时行颈椎正侧位X线片、CT三维重建和MRI检查,测量术前及随访时的颈椎矢状位参数,包括C2-C7 Cobb角、C2-C7矢状面轴向距离(sagittal vertical axis,SVA)和T1倾斜角。结果:末次随访时JOA评分及VAS评分较术前明显改善(P0.001),神经功能恢复为优者21例,良30例,中14例,差3例,优良率为75%。末次随访时C2-C7 Cobb角由术前的15.4°±9.5°增大到17.4°±10.2°,但差异无统计学意义(P=0.166);C2-C7 SVA由术前的21.0±15.3mm增大到27.0±15.7mm,差异有统计学意义(P=0.009);T1倾斜角由术前的30.2°±10.1°增大到33.7°±8.0°,差异有统计学意义(P=0.044)。术前T1倾斜角与C2-C7 Cobb角正相关(r=0.569,P0.01),与C2-C7 SVA正相关(r=0.544,P0.01)。C2-C7 Cobb角与C2-C7 SVA无显著相关性(r=0.05,P=0.798)。末次随访时C2-C7 Cobb角较术前增大24例,较术前减小44例,两组JOA评分和VAS评分变化、神经功能改善率无统计学差异;C2-C7SVA增加46例,减小22例,两组JOA评分和VAS评分变化、神经功能改善率亦无统计学差异(P0.05)。结论 :颈后路单开门椎管扩大成形术治疗OPLL短期疗效确切,手术前后颈椎矢状参数的变化与患者的临床疗效无显著相关性。     

C3-7单开门椎管扩大成形术后颈椎矢状位序列的变化及其与颈椎功能的相关性

目的:探究颈椎单开门椎管扩大成形术后全颈椎矢状位序列的变化,探讨颈椎矢状位序列变化的意义及其与患者颈椎功能状态的关系。方法:回顾性分析我院2015年1月～2018年7月收治的脊髓型颈椎病患者164例,其中男性95例,女性69例,年龄64.8±18.3(48～86)岁。随访时间22.7±11.3(9～46)个月。所有患者均行C3-7后路单开门椎管扩大成形术。在患者术前和末次随访的颈椎侧位X线片上测量颈椎矢状位序列参数:C1-2 Cobb角、C2-7 Cobb角、颈椎弧弦距(cervical arc chord distance,CACD)、颈倾角(cervical tilting,CERT)、颅倾角(cranial tilting,CRAT)、颈总角(cervical global alignment,CGA)、T1倾斜角(thoracic 1 slope,T1S),C7倾斜角(C7 slope,C7S)和C2-7矢状垂线轴(C2-7 sagittal vertical axis,SVA)。记录入组患者术前及末次随访时颈痛视觉模拟评分(visual analog scale,VAS)及改良日本骨科协会评分(modified Japanese Orthopaedic Association,mJOA)评分,采用配对样本t检验比较手术前后各参数的变化,Pearson相关性分析颈椎矢状位序列参数变化之间的相关性及与颈椎功能状态评分(颈痛VAS、mJOA评分)的相关性。结果:颈椎单开门椎管扩大成形术后T1S较术前减小1.25°±3.34°(21.38°±7.54°vs 20.13°±7.16°,P=0.004),C7S较术前减小0.44°±4.23°(28.05°±7.72°vs 27.61°±7.81°,P=0.012),C2-7 Cobb角较术前减小5.51°±6.88°(15.92°±12.57°vs10.40°±10.93°,P0.001),CACD较术前减小1.50±3.92mm (6.94±5.69mm vs 5.44±5.52mm,P=0.003),CERT较术前减小2.23°±5.27°(13.45°±6.37°vs 11.22°±6.78°,P=0.001),C2-7 SVA较术前增大3.35±9.90mm (18.20±9.05mm vs 21.55±10.65mm,P=0.009),C1-2 Cobb角较术前增大2.06°±5.09°(39.56°±0.46°vs 41.62°±0.70°,P=0.002)。末次随访VAS(1.52±1.47分)显著高于术前(1.02±1.12分,P=0.007)。Pearson相关性分析显示C2-7SVA、CACD、CGA、C2-7 Cobb角、C1-2 Cobb角、CERT、CRAT的变化相互之间有显著统计相关性(P0.05)。手术前后VAS的变化与C2-7 SVA (r=0.462,P0.001)、C1-2 Cobb角(r=0.362,P0.01)及CRAT (r=0.323,P0.01)的变化呈正相关,与CGA(r=-0.316,P0.01)及CACD变化(r=-0.344,P0.01)呈负相关,mJOA评分手术前后的变化与C2-7 SVA(r=0.273,P0.05)及C1-2 Cobb角(r=0.298,P0.05)的变化呈正相关。结论:C3-7单开门椎管扩大成形术后出现下颈椎生理曲度变直,头部重心位置前移,上颈椎及颈胸段脊柱过伸。C3-7单开门椎管扩大成形术后轴性症状加重与颈椎矢状位序列的变化有关。     

枕颈融合术后Takami枕颈角与下颈椎曲度的相关性分析

目的 :分析枕颈融合术后Takami枕颈角(Takami′s occipitocervical angle,TOCA)与下颈椎曲度的相关性分析,探讨术中枕颈固定合适的TOCA范围。方法:收集50例无颈部畸形、颈椎退变、颈部外伤史及手术史的成人(对照组)颈椎侧位X线片,测量TOCA及C2-C7 Cobb角。回顾性分析2010年1月～2016年12月于我院行后路枕颈融合手术并成功获得随访的17例颅底凹陷症(basilar invagination,BI)患者(BI组),在颈椎侧位X线片上分别测量术前、术后即刻和末次随访时TOCA及C2-C7 Cobb角,并以术后即刻TOCA为依据,参考正常组TOCA大小,将患者分为A、B、C三组(A组TOCA83°;B组TOCA为83°～89°;C组TOCA89°),收集A、B、C三组中术前、术后即刻及末次随访时的TOCA与C2-C7 Cobb角大小,以及正常组中TOCA与C2-C7Cobb角大小,进行t检验及Pearson相关性分析。结果:对照组TOCA平均为86.2°±2.7°,C2-C7 Cobb角平均为17.4°±3.9°;对照组及BI组术前、末次随访时TOCA与C2-C7 Cobb角均呈正相关(P0.05)。A组中C2-C7Cobb角术前与末次随访相比差异无统计学意义(P=0.088),但A组中C2-C7 Cobb角均值由术前15.4°±3.5°减至末次随访时11.7°±2.6°;B组中术前C2-C7 Cobb角(20.0°±4.5°)与末次随访时(21.8°±4.7°)相比无统计学差异(P0.05);C组中术前C2-C7 Cobb角(21.6°±2.3°)与末次随访时(30.0°±4.3°)相比有统计学差异(P0.05)。结论:颅底凹陷症患者行枕颈融合术中TOCA固定在83°～89°能够减少对下颈椎曲度的影响。     

颅底凹陷症合并寰枢椎脱位患者枕颈角与下颈椎曲度的关系

目的:评估颅底凹陷症(basilar invagination,BI)合并寰枢椎脱位(atlantoaxial dislocation,AAD)患者枕颈角(O-C2角)与下颈椎曲度(C2-7 Cobb角)之间的关系。方法:回顾性分析2009年1月~2013年6月21例于我院因BI合并AAD行后路复位枕颈融合术患者的临床资料。21例患者中男12例,女9例;年龄21~65岁(41.6±10.7岁);病程4个月~18年(4.3±3.9年)。于手术前和术后末次随访时在颈椎中立位侧位X线片上测量O-C2及C2-7 Cobb角(C2-7角),并计算O-C2角及C2-7角的变化量dO-C2角和dC2-7角,前凸为“+”值,后凸为值。根据O-C2角的大小,将21例患者术前和末次随访时分为10°≤O-C2角≤20°组、O-C2角10°组及O-C2角20°组。观测手术前后不同O-C2角组C2-7角的差异,分析手术前后O-C2角与C2-7角的相关性。结果:21例患者中,12例患者固定节段为C0-C3,9例患者为C0-C4。随访时间为10~32个月(18.3±6.6个月)。术后末次随访时O-C2角较术前平均增大6.3°,C2-7角较术前平均减小6°,手术前后两指标比较均存在显著性差异(P0.05)。术前6例(28.6%)患者O-C2角在10°~20°间,12例(57.1%)10°,3例(14.3%)20°。OC2角10°组C2-7角显著大于O-C2角10°~20°组及20°组(P0.05),O-C2角10°~20°组与20°组比较无显著性差异(P0.05)。末次随访时10例(47.6%)患者O-C2角在10°~20°间,4例(19.0%)20°,7例(33.4%)10°,O-C2角20°组C2-7角显著小于O-C2角10°~20°组及10°组(P0.05),O-C2角10°~20°组与10°组比较无显著性差异(P0.05)。术前及术后末次随访时O-C2角与C2-7角均存在显著性负相关(术前r=-0.732,P0.05;术后r=-0.603,P0.05);d0-C2角及dC2-7角亦存在显著性负相关(r=-0.721,P0.05)。结论:BI合并AAD患者枕颈角与下颈椎曲度关系密切,行后路复位枕颈融合术时需监测枕颈角的固定角度,若枕颈角过大有可能导致术后下颈椎曲度出现代偿性减小。     

先天性颈胸段脊柱畸形后路截骨矫形术后颈椎序列变化及其影响因素

目的 :分析先天性颈胸段脊柱畸形经后路截骨矫形术后颈椎序列变化及其影响因素。方法:回顾性分析2012年3月～2017年3月于我院行后路截骨矫形术治疗的26例先天性颈胸段脊柱畸形患者的临床及影像学资料,男10例,女16例,年龄14.2±4.6岁(9～20岁),随访时间38.0±6.4个月(24～96个月)。畸形节段位于C6～T5,其中半椎体5例,楔形椎2例,蝴蝶椎3例,半椎体合并蝴蝶椎4例,半椎体合并骨桥7例,阻滞椎5例。融合节段7.7±3.2个(3～13个)。收集患者术前、术后2周及末次随访时站立全脊柱正侧位X线片,测量冠状面影像学参数,包括原发及远端代偿弯Cobb角、冠状面T1倾斜角(T1 tilt)、锁骨角(clavicle angle,CA)、颈部倾斜(neck tilt,NT)、头部偏斜(head shift,HS)及冠状面平衡距离(coronal balance distance,CBD);测量矢状面影像学参数,包括颈椎矢状垂直轴(C2-C7 sagittal vertical axis,C2-C7 SVA)、颈椎前凸角(cervical lordosis,CL)、颈胸后凸角(cervicothoracic kyphosis,CTK)、矢状面上端椎(upper end vertebrae,UEV)/T1倾斜角、胸椎后凸角(thoracic kyphosis,TK)、胸段后凸角(UEV/T1-T12)、腰椎前凸角(lumbar lordosis,LL)、骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、矢状垂直轴(sagittal vertical axis,SVA)偏距。根据术前颈椎序列将患者分为前凸组(CL-5°)及僵直/后凸组(CL≥-5°),前凸组8例,僵直/后凸组18例。根据术后至末次随访期间颈椎僵直/后凸是否发生进展(△CL5°为进展)将术前僵直/后凸组患者分为后凸进展亚组(7例)与后凸无进展亚组(11例)。比较组间影像学参数差异,通过Pearson相关系数分析术前、术后及末次随访时可能影响颈椎曲度变化的影像学参数,评估SRS-22量表评分。应用Pearson卡方检验、Fisher精确检验、配对及独立t检验及Pearson相关系数分析比较组间影像学参数及SRS-22量表评分差异。结果 :26例患者原发弯平均矫正率67.0%,远端代偿弯平均矫正率47.9%,HS、NT、CBD、T1 tilt、CA末次随访时均较术前明显改善(P0.05)。颈椎前凸组术前、术后、末次随访时矢状面参数无统计学差异(P0.05)。颈椎前凸组术前UEV/T1倾斜角及术前UEV/T1-T12较颈椎僵直/后凸组有统计学差异(分别为20.2°±0.5°vs 16.4°±4.3°,49.3°±5.2°vs 36.3°±14.3°,均P0.05)。颈椎僵直/后凸组术前4例伴颈椎矢状面失平衡(C2-C7 SVA≥4cm),颈椎后凸进展组与无进展组比较,术前矢状面参数均无明显差异;术后CTK(2.4°±3.9°vs 12.7°±4.3°,P0.05)、UEV/T1-T12(18.7°±3.6°vs37.8°±7.6°,P0.05)有统计学差异,其余无统计学差异;末次随访时,CTK(5.2°±4.9°vs 11.7°±6.5°,P0.05)、UEV/T1-T12(20.4°±7.5°vs 38.5°±9.4°,P0.05)、LL(-46.4°±7.9°vs-36.4°±5.2°,P0.05)、SVA(-5.3cm±1.2cm vs-2.8cm±2.0cm,P0.05)有统计学差异,其余无统计学差异(P0.05)。术前颈椎后凸与术前UEV/T1-T12呈负相关(r=-0.398,P=0.045),术后颈椎后凸与术后CTK呈正相关(r=0.673,P0.001),末次随访颈椎后凸进展与术后-末次随访△LL(r=0.557,P=0.020)及△SVA呈正相关(r=0.496,P=0.034)。SRS-22量表评估术前颈椎僵直/后凸组自我形象及心理健康维度评分低于颈椎前凸组(P0.05),末次随访时颈椎后凸进展组疼痛评分低于颈椎前凸组及颈椎后凸无进展组(P0.05),颈椎前凸组、颈椎后凸无进展组总评分均优于颈椎后凸进展组(P0.05)。结论:先天性颈胸段脊柱畸形患者颈椎后凸发生率较高,术前颈椎后凸可能与UEV/T1-T12过小有关。一期后路截骨矫形术后,CTK过小、术后LL增大及SVA后移可导致远期颈椎后凸进展。     

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.