顶椎远端截骨治疗强直性脊柱炎胸腰椎后凸畸形

目的 :探讨顶椎远端经椎弓根椎体截骨(pedicle subtraction osteotomy,PSO)治疗强直性脊柱炎(ankylosing spondylitis,AS)胸腰椎后凸畸形的适应证和疗效。方法:2001年1月～2017年8月采用顶椎远端PSO手术治疗39例AS胸腰椎后凸畸形患者,男35例,女4例;年龄20～59岁(38.2±10.5岁)。顶椎分布于T9～L1之间。9例合并假关节,其中5例位于顶椎远端者伴神经功能损害,4例位于顶椎者不伴神经功能损害。2例术前已行双侧髋关节置换术;37例术前伴一侧或双侧髋关节功能障碍,巴氏AS放射指数(BASRI)左侧为2.56±0.77分,右侧为2.42±0.65分,其中24例患者单侧或双侧髋关节间隙明显狭窄(BASRI≥3分)。22例术前腰椎前凸不足,1例腰椎后凸。腰背痛VAS评分4.83±2.03。记录患者的截骨节段和手术并发症;术前、术后及末次随访时摄站立位全脊柱正、侧位X线片,测量胸腰椎最大后凸角(global kyphosis,GK)、矢状面躯干偏移(sagittal vertical axis,SVA)、腰椎前凸角(lumbar lordois,LL)、固定节段后凸角(angle of fused segments,AFS)和颌眉角(chin-brow vertical angle,CBVA)。结果:39例患者均完成矫形手术,截骨节段:T12 2例,L1 8例,L2 16例,L3 12例,L5 1例。1例术中截骨椎脱位;1例术中不良置钉;1例术中硬脊膜破裂,术后脑脊液漏;无术中大血管损伤、术后无感染等并发症。术后所有患者后凸畸形及平视功能得到改善,腰背痛症状缓解。随访14～144个月(40.26±28.52个月),2例内固定断裂,其中1例行翻修术,3个月随访内固定在位,融合良好;1例无症状,固定区域稳定,未处理。所有患者术后无假关节形成。术前GK、LL、SVA、CBVA分别为69.47°±14.37°、19.32°±19.19°、120.77±48.34mm、23.00°±17.08°,术后分别为28.76°±12.83°、51.62°±16.08°、26.56±41.12mm、4.19°±6.58°,末次随访时分别为30.53°±13.95°、49.32°±16.64°、32.56±35.14mm、4.78°±6.22°,术后与术前比较均有显著性差异(P0.05),末次随访时与术后比较均无统计学差异(P0.05)。术后AFS平均为22.77°±10.86°,末次随访时为24.29°±10.99°,无统计学差异(P0.05)。末次随访时VAS评分为1.82±1.64,与术前比较有显著性差异(P0.05)。结论:AS胸腰椎后凸畸形患者于顶椎远端行PSO手术可以明显改善矢状面平衡,对以矫正SVA为主要目的、术前顶椎区假关节不伴有神经损害、顶椎远端假关节伴有神经损害、术前髋关节功能受限、顶椎位置位于胸腰段以上、腰椎前凸不足或后凸且顶椎位置位于胸腰交界处的患者,于顶椎远端截骨可以取得满意手术疗效。     

经关节突“V”形截骨与经椎弓根椎体截骨对脊柱-骨盆复合体平衡的影响

 目的 比较多节段经关节突“V”形截骨(Smith-Petersen osteotomies,SPOs)与经椎弓根椎体截骨(pedicle subtraction osteotomy,PSO)重建强直性脊柱炎胸腰椎后凸畸形患者脊柱-骨盆复合体平衡的效果。方法 2000年8月至2010年6月应用SPOs或PSO矫形内固定术治疗39例强直性脊柱炎胸腰椎后凸畸形患者。SPOs组15例,男13例,女2例;年龄18~42岁,平均(28.1±7.1)岁。PSO组24例,男20例,女4例;年龄21~53岁,平均(38.3±7.9)岁。比较两组患者术前、术后3个月及末次随访的脊柱-骨盆参数：胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)、全脊柱最大后凸Cobb角(global kyphosis,GK)、矢状面平衡(sagittal vertical axis,SVA)、骨盆投射角(pelvic incidence,PI)、骶骨倾斜角(sacral slope,SS)和骨盆倾斜角(pelvic tilting,PT)。结果 除TK和PI外,其他参数手术前后比较差异均有统计学意义。术前测量指标除PI、GK及LL外,其他参数两组间比较差异均无统计学意义;术后LL、GK、PT及SS两组间比较差异有统计学意义。末次随访时,SVA、LL、GK、PT及SS的矫正丢失两组间比较差异有统计学意义。结论 对强直性脊柱炎胸腰椎后凸畸形患者,PSO能够获得更好的脊柱-骨盆复合体平衡重建,而SPOs易于发生远期矫正度丢失。     

马凡综合征伴脊柱畸形患者脊柱-骨盆矢状面的形态特征

目的:探索马凡综合征伴脊柱畸形患者脊柱-骨盆矢状面的形态特征。方法:收集以脊柱畸形来我院就诊的马凡综合征患者35例,男18例,女17例,年龄10~20岁,平均14.4±2.3岁。在站立位全脊柱侧位X线片上测量脊柱及骨盆矢状面参数,包括:(1)胸椎后凸角(thoracic kyphosis,TK),(2)胸腰段后凸角(thoracolumbar kyphosis,TL),(3)腰椎前凸角(lumbar lodorsis,LL),(4)骨盆入射角(pelvic incidence,PI),(5)骨盆倾斜角(pelvic tilt,PT),(6)骶骨倾斜角(sacral slope,SS),(7)矢状面平衡(sagittal vertical axis,SVA)。定义顶椎在T12、L1或者T12/L1椎间盘,后凸角度10°的后凸为胸腰段后凸;顶椎在L1/2椎间盘或以下椎体、椎间盘,后凸角度10°的后凸为腰椎后凸。采用Sponseller分型方法对患者脊柱矢状面形态进行分型,比较不同分型患者脊柱-骨盆矢状面形态。结果:本组患者在冠状面上以胸腰双弯(40.0%)、单胸弯(22.8%)以及三弯(20.0%)最常见,最大Cobb角43°~165°,平均75.2°±26.0°。在脊柱矢状面上,TK为-25°~73°(19.0°±24.1°),其中胸椎后凸正常者(20°≤TK≤50°)10例(28.6%);胸椎后凸增大患者(TK50°)5例(14.3%);胸椎后凸减小者(0°≤TK20°)13例(37.1%);另有7例(20.0%)患者表现为胸椎前凸。TL为-25°~73°(14.0°±19.0°);LL为-17°~70°(37.1°±23.3°);SVA为-9.0~7.2cm(-2.0±4.3cm)。15例(42.9%)患者表现为胸腰段后凸或腰椎后凸(9例ⅡA型,6例ⅡB型),5例患者表现为后凸区明显的椎体楔形变。骨盆矢状面上,PI为25°~74°(40.1°±12.7°);PT为-12°~34°(6.9°±9.6°);SS为14°~68°(33.3°±12.6°)。Sponseller分型Ⅰ型患者TK、LL、PI、SS明显大于Ⅱ型患者,而Ⅱ型患者TL明显大于Ⅰ型患者。未见腰椎滑脱现象。结论:马凡综合征伴脊柱畸形患者脊柱-骨盆矢状面形态差异较大,手术医生应该根据不同分型制定不同的手术策略。     

SRS-SchwabⅥ级截骨术联合卫星棒技术治疗严重脊柱角状后凸畸形的短期疗效

目的探讨SRS-Schwab Ⅵ级截骨术联合卫星棒技术治疗严重脊柱角状后凸畸形的影像学及临床疗效。方法回顾性分析2011年6月至2021年6月于南京大学医学院附属鼓楼医院接受SRS-Schwab Ⅵ级截骨术联合卫星棒技术治疗的19例严重脊柱角状后凸畸形患者的资料, 男8例、女13例, 年龄(39.7±11.2)岁(范围23～58岁)。病因学包括先天性脊柱后凸畸形8例、结核性脊柱后凸畸形11例。影像学测量参数包括最大后凸Cobb角(global kyphosis, GK)、胸椎后凸角(thoracic kyphosis, TK)、腰椎前凸角(lumbar lordosis, LL)、矢状面平衡(sagittal vertical axis, SVA)、骨盆倾斜角(pelvic-tilt, PT)、骨盆入射角(pelvicincidence, PI)和骶骨倾斜角(sacral slope, SS)等。应用脊柱侧凸研究学会-22简明量表调查问卷(Scoliosis Research Society questionnaires-22, SRS-22)评估临床疗效。采用美国脊柱损伤协会(Ame...     

经椎弓根不对称截骨术矫正强直性脊柱炎胸腰椎侧后凸畸形的疗效分析

目的 ：分析经椎弓根不对称截骨术（asymmetrical pedicle subtraction osteotomy,APSO）对强直性脊柱炎（ankylosing spondylitis,AS）胸腰椎侧后凸畸形患者的临床疗效,并比较其与传统经椎弓根椎体截骨术（pedicle subtraction osteotomy,PSO）对矢状面平衡重建的疗效。方法：回顾性分析2016年1月～2019年6月在我院行脊柱截骨术且随访超过1年的55例AS胸腰椎畸形患者。仅有矢状面畸形的AS患者采用PSO,双平面畸形患者采用APSO。在术前、术后和末次随访时的站立全脊柱正侧位X线片上测量冠状面Cobb角、冠状面平衡距离（coronal balance distance,CBD）、全脊柱后凸角（global kyphosis,GK）、矢状面偏移（sagittal vertical axis,SVA）、骨盆倾斜角（pelvic tilt,PT）、骶骨倾斜角（sacral slope,SS）、腰椎前凸角（lumbar lordosis,LL）、截骨角（osteotomized vertebral angl...     

脊柱侧后凸/后凸畸形SRS-Schwab四级截骨术后近端交界性后凸的危险因素分析

目的:探讨脊柱侧后凸/后凸畸形患者SRS-Schwab四级截骨术后发生近端交界性后凸(proximal junctional kyphosis,PJK)的相关危险因素。方法:回顾性分析2011年5月～2015年12月于我院行SRS-Schwab四级截骨手术且具有完整临床及影像学资料的46例脊柱侧后凸/后凸畸形患者,其中男性24例,女性22例,手术时年龄23.1±19.7岁。记录患者体重指数、融合节段、最上端固定椎(upper instrumented vertebra,UIV)位置及置钉密度等。测量术前、术后3个月及末次随访时的胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)、骨盆入射角(pelvic incidence,PI)、局部后凸角(segmental kyphosis,SK)、主弯Cobb角(main curve,MC)、矢状面平衡(sagittal vertical axis,SVA)及近端交界角(proximal junctional angle,PJA)。根据患者术后是否发生PJK分为非PJK组和PJK组,采用t检验、χ2检验或Fisher精确检验对比两组临床资料及影像学参数,利用多因素Logistic回归分析确定PJK发生的危险因素。结果:46例患者术后随访24～63个月(36.9±13.4个月),其中11例(23.9%)发生PJK,以Ⅰ型PJK(8/11)最为常见,8例发生于术后6个月内。PJK组和非PJK组患者性别、年龄、随访时间、体重指数、融合节段、骨密度、置钉密度、UIV位置均无统计学差异(P0.05)。PJK组患者术前TK40°(6/11)和SK矫正30°(7/11)的比例均高于非PJK组(P0.05)。两组患者间术前PJA、LL、MC、PI、SVA和术后及末次随访时TK、LL、MC、SK、PI、SVA改变均无统计学差异(P0.05)。回归分析结果显示术后SK矫正30°(OR=7.000,95%CI=1.591-30.800,P=0.010)是PJK发生的独立危险因素。PJK组术前PJA为7.5°±3.0°,术后3个月为20.8°±4.1°,末次随访时为22.0°±4.5°,交界性后凸未见明显加重。结论:脊柱侧后凸/后凸畸形患者SRS-Schwab四级截骨术后PJK发生率为23.9%,其主要发生于术后6个月内,脊柱后凸畸形过度矫正是其独立危险因素。     

中老年人群脊柱-骨盆矢状位参数及其序列拟合关系

目的 :测量我国中老年人群的脊柱-骨盆矢状位参数并分析其相关性,建立腰椎前凸角与相关脊柱-骨盆矢状位参数的拟合关系。方法:采用影像学测量方法,对106例中老年志愿者进行研究,其中男48例,女58例;年龄62.4±5.2岁(55~76岁)。所有志愿者行全脊柱正、侧位X线摄片,利用院内影像归档与通信系统(picture archiving and communication system,PACS)测量骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)、腰椎前凸角(lumber lordosis,LL)、上腰弯前凸角(upper arc of total lumbar lordosis,UALL)、下腰弯前凸角(lower arc of total lumbar lordosis,LALL)、胸椎后凸角(thoracic kyphosis,TK)、矢状位平衡(sagittal vertical axis,SVA)等参数,按照脊柱矢状面解剖定义和形态特点分析脊柱-骨盆矢状位形态参数及其相关性,并与青年人群相关参数进行比较,利用线性回归分析建立中老年人群LL与PI、TK的拟合关系。结果 :我国中老年人群的PI为46.5°±7.6°,PT为13.1°±6.6°,SS为32.3°±9.5°,LL为49.2°±9.1°,UALL为15.9°±5.9°,LALL为32.3°±9.5°,TK为34.0°±10.7°,SVA为-5.0±30mm;LL与SS、TK、PI、PT、SVA呈显著性相关(P0.05),PT与TK、SS呈显著性相关(P0.05),UALL与TK、SVA相关,LALL与PI相关。中老年人群与青年人群比较PI、SS、LL、LALL无显著性差异(P0.05),PT、TK、SVA、UALL有显著性差异(P0.01)。中老年人群LL预测值=0.6PI+0.4TK+10°,R2=0.375。结论:中老年人群中LL与其他相关脊柱-骨盆各参数之间存在显著相关性,我国中老年人群LL的理想预测值为LL=0.6PI+0.4TK+10°;TK、UALL、PT、SVA与青年人群有显著性差异。     

单节段与双节段经椎弓根椎体截骨术重塑强直性脊柱炎重度胸腰椎后凸畸形患者腰椎前凸曲线的效果及术式选择

【摘要】 目的：分析单节段和双节段经椎弓根椎体截骨术（pedicle subtraction osteotomy,PSO）在强直性脊柱炎（ankylosing spondylitis,AS）重度胸腰椎后凸畸形（后凸Cobb角≥80°）患者中重塑其腰椎前凸曲线的效果,探讨两种术式的适应证。方法：回顾性分析68例接受PSO手术治疗的AS重度胸腰椎后凸畸形患者,其中44例接受单节段PSO治疗,24例接受双节段PSO治疗,随访时间为36.50±15.07个月。所有患者均在术前及末次随访时填写Oswestery功能障碍指数（Oswestry disability index,ODI）量表和视觉模拟量表（visual analogue scale,VAS）。测量术前、术后及末次随访时的胸腰椎后凸Cobb角（global kyphosis,GK）、矢状面躯干偏移（sagittal vertical axis,SVA）、胸椎后凸角（thoracic kyphosis,TK）、腰椎前凸角（lumbar lordosis,LL）、骨盆倾斜角（pelvic tilt,PT）和骶骨倾斜角（sacral slope,SS）。将68例分别接受单节段和双节段PSO患者对比分析后,根据患者术后腰椎前凸顶点的位置分为两组,腰椎前凸顶点在L3或L4组（30例）,腰椎前凸顶点在L5或其他腰椎组（38例）,比较两组腰椎曲线的大小及形态。将良好的腰椎前凸曲线重塑定义为术后腰椎前凸顶点位于L3或L4水平,进一步筛选出30例实现良好的腰椎前凸曲线重塑的患者,再将其分为单节段PSO组（20例）和双节段PSO（10例）组,使用受试者操作特征（receiver-operating characteristic,ROC）曲线确定这两组之间存在显著性差异的术前影像学参数的最佳临界值（cut-off值）。结果：在68例重度胸腰椎后凸畸形患者中,接受单节段PSO组与双节段PSO组患者术后腰椎前凸顶点的分布无显著性差异（P＞0.05）,但是双节段PSO组手术时间更长、术中失血更多、固定节段更长（P<0.05）。术后腰椎前凸顶点在L5或其他腰椎组患者术后的LL和SS均显著小于L3或L4组（P<0.001）,而两组患者术后的GK、SVA、TK和PT均无显著性差异（P＞0.05）;不同的截骨水平及截骨术式对术后腰椎前凸顶点的分布均无显著影响（P＞0.05）。在30例实现良好的腰椎前凸曲线重塑的患者中,术后除TK外的所有脊柱骨盆参数较术前明显改善,ODI、VAS评分均有明显改善（P<0.05）,随访过程中也未见明显的矫正丢失;其中,双节段PSO组术前的GK、SVA和LL明显大于单节段PSO组（P<0.05）,其余的术前参数两组比较均无统计学差异（P＞0.05）。ROC曲线分析结果表明,GK的cut-off值为94.50°,SVA的cut-off值为19.35cm,LL的cut-off值为12.00°。单节段PSO组并发症包括2例截骨椎脱位、1例体位性臂丛神经麻痹和1例术中硬脊膜撕裂,双节段PSO组并发症包括2例体位性臂丛神经麻痹、1例截骨椎脱位和1例随访期间内固定棒断裂。结论：单节段和双节段PSO均能为AS重度胸腰椎后凸畸形的患者实现良好的腰椎前凸曲线重塑,术式的选择取决于患者术前后凸畸形的严重程度。对于GK<94.50°、SVA<19.35cm及LL<12.00°的患者,首先考虑单节段PSO以实现良好的腰椎前凸曲线重塑;相反地,对于脊柱矢状位失衡更严重（GK≥94.50°、SVA≥19.35cm及LL≥12.00°）的患者,双节段PSO是重塑良好腰椎前凸曲线的更佳选择。     

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。     

强直性脊柱炎胸腰段脊柱后凸截骨术矢状面移位患者椎管自发重塑形现象

目的:观察强直性脊柱炎(ankylosing spondylitis,AS)脊柱后凸畸形截骨术发生矢状面移位(sagittal translation,ST)患者椎管形态的变化以及椎管自发重塑形现象。方法:回顾性分析2011年1月~2014年12月于我院行经椎弓根截骨术发生ST的16例AS胸腰段脊柱后凸畸形患者,男14例,女2例,年龄28~55岁(38.6±8.4岁)。均于手术前后及末次随访时拍摄自然站立位全脊柱正侧位X线片以及ST节段三维CT扫描,分别测量全脊柱后凸角(GK)、胸腰段后凸角(TLK)、腰前凸角(LL)、矢状面偏移(SVA)以及ST的大小,观察术后及末次随访时ST的变化以及椎管形态的改变,并于术前及末次随访时通过SRS问卷对患者生活质量进行评估。结果:所有患者均获得随访,随访时间12~36个月(22.0±8.5个月),随访期内所有病例均未出现内固定失败。术前GK为59.9°±21.0°、TLK为38.0°±13.0°、LL为7.4°±26.5°、SVA为27.2±8.6mm,术后末次随访时GK为15.7°±2.1°、TLK为5.6°±2.6°、LL为-36.1°±2.9°、SVA为6.1±4.3mm,末次随访时所有患者ST均有改善,ST由术后7.1±2.7mm减小为末次随访时的1.2±1.0mm,差异有统计学意义(P0.05),ST变化率为(84.9±9.7)%。4例患者出现神经并发症。SRS满意度调查术前评分为1.6±0.3分,末次随访时评分为4.7±0.4分,差异有统计学意义(P0.05)。末次随访时截骨节段的椎管形态均有不同程度的自发重塑形。结论:AS脊柱胸腰段后凸畸形截骨术发生ST的患者术后均会发生不同程度的椎管自发重塑形,经过重塑形ST均不同程度的减小甚至消失。     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.