胎羊宫内窘迫时脐血流变化的超声多普勒研究

目的：通过经胎羊动脉插管注射微球悬液建立胎羊宫内窘迫的动物模型。方法：在经胎羊动脉插管取血进行胎羊血气分析的同时、检测了脐血流阻力指标。结果：（１）注射微球后胎羊脐动脉的阻力升高;（２）脐血流的变化与胎羊宫内窘迫时脐动脉血气变化同步。     

超声诊断无盘绕脐血管及其对围生儿的影响分析

正常脐带略呈螺旋状迂曲走行,即两条动脉盘绕一条静脉走行.常见的脐带异常有脐带缠绕、脐带扭转、脐带打结、脐带先露及脐带脱垂等[1].有关无盘绕脐血管,即三条脐血管平行排列走行,报道甚少.由于脐血管失去正常螺旋状结构,分娩过程中极易造成脐血管受压、脐血流改变,可发生胎儿宫内窘迫,严重者可导致胎死宫内[2].     

脐带缠绕所致脐血流异常的临床分析

目的 探讨孕晚期（孕37周后）胎儿脐血流频谱和脐带缠绕血流频谱的特点.方法 对孕37周后的胎儿脐血流和脐带缠绕脐血流进行动态频潜监测.结果 孕37周后正常胎儿的脐动脉平均血流速度〈19cm/s,脐静脉血流速度〈10cm/s.脐带绕颈及发生在其它部位缠绕者,脐动脉平均血流速度〉21cm/s,脐静脉血流速度〉11cm/s（P均〈0.05）.结论 当孕晚期发生胎儿脐带缠绕（含脐带绕颈）、特别是大于1周时,脐动脉、脐静脉血流速度加大,与自然飘浮于羊水中的脐血流速度存在一定的差异性.     

脐血血气综述

ACOG（美国妇产学会）指出脐血血气是胎儿出生时代谢状态的最客观的反映。胎儿期肺部处于压缩状态，通过脐带与胎盘连接进行气体交换及物质代谢产物的排泄，正常情况下，胎儿体内处于酸碱平衡状态，当胎儿缺血缺氧时，机体通过缓冲系统的调节与HCO3^-反应产生CO2，经脐动脉通过胎盘扩散到母血中，以维持胎儿体内的酸碱平衡。当严重缺氧或缺氧持续存在时，胎盘功能及胎儿血的缓冲能力有限，导致CO2及乳酸蓄积，二氧化碳分压（PCO2）增加，碱剩余（BD）及HCO3^-值下降，pH值亦降低，呈混合性酸中毒状态，通过血气分析可及时反映出来。     

单脐动脉7例分析

脐带的主要功能是输送血液，胎儿血液经脐带和胎盘与母体进行营养和代谢物质的交换，正常脐带应有两条脐动脉和一条脐静脉。如果仅有一条脐动脉称为单脐动脉。许多学者发现其与出生缺陷关系十分密切［‘，‘］，因此已日益受到重视。现将本院所遇的7例单脐动脉报道如下。1临床资料我院1991年1月至1994年12月对346例围产）L尸体检查和（或）胎盘检查，共发现单脐动脉7例，发生率为202％。7例单脐动脉的临床资料及病理检查结果见表1。2讨论在脐动脉的发育过程中，由于一条脐动脉发育不良或萎缩，或在早期（3．4～4．0毫米胚胎体蒂）暂时出现…     

帆状胎盘的产前超声诊断研究

目的 探讨应用二维彩色多普勒超声观察脐带帆状附着前及附着后异常脐血管走行特点对帆状胎盘的诊断价值.方法 选择我院接受产前超声检查并诊断帆状胎盘42例,结合产后病理检查,分析其声像图特征.结果 本组病例中产前超声检查诊断帆状胎盘42例,产后病理证实帆状胎盘35例,球拍状胎盘7例,符合率83％(35/42).总结脐带帆状附着前及附着后脐血管的走行有以下表现:(1)见多处单根脐动脉与单根脐静脉伴行出入胎盘;(2)脐动脉进入胎盘前或脐静脉出胎盘后呈单根独立走行;(3)脐动脉进入胎盘前先发出分支或脐静脉出胎盘后再汇合.结论 脐带帆状附着前及附着后异常脐血管的走行可作为超声诊断帆状胎盘的线索,在提高产前超声诊断帆状胎盘的准确率方面有重要的临床价值.     

脐动脉传输线模型评价胎盘功能的临床应用

目的　探讨评价胎盘功能的新方法。方法　分别取脐动脉的胎儿端和胎盘端 ,利用彩色多普勒超声获得脐动脉多普勒信号 ,转化为声音信号后输入计算机 ,并计算胎盘的阻力 (RL)和搏动指数 (PI)、阻力指数(RI) ,同时多普勒频谱中测定脐动脉搏动指数 (Pia)、脐动脉阻力指数 (Ria)、脐动脉血流阻力 (S/D)。结果　脐动脉血流阻抗随孕周的增加而降低。比较正常和异常妊娠时脐动脉血流阻力指标 ,发现脐动脉传输线模型测定胎盘血流阻抗值较临床上常规指标更为敏感 ,胎盘端脐动脉传输线模型测定胎盘血流阻抗值在异常妊娠组明显高于正常妊娠组。结论　脐动脉传输线模型测定的胎盘血流阻抗是一项较为敏感的监测指标 ,可以客观地反映胎盘床血流阻力的变化 ,在发现异常妊娠方面具有一定的临床价值。     

彩超诊断脐带绕躯干两周一例

孕妇,26岁,孕1产0,40周妊娠,因有产兆急诊入院,产程不进展,胎头高浮。行B超检查见:上方,双顶径9.0cm,沿胎儿长轴探查,儿腰部皮肤呈现“W”形压迹(见图1),彩超观察有彩色脐带血流信号,旋转探头90°可见兰红彩色脐血平行走向,且可分别测及脐动脉,脐静脉血流频谱;胎心博动良好。胎盘位于子宫右前壁,羊水量正常范围。B超诊断:40周妊娠,     

胎儿脐血流及胎心监护联合监测在脐带绕颈分娩方式选择上的应用价值

目的 :探讨胎儿脐血流及胎心监护在脐带绕颈分娩方式选择上的应用价值。方法 :选择 6 45例入院时未临产的单胎头位妊娠的孕妇 ,先行胎儿脐血流检查 ,对其中 136例提示脐带绕颈的孕妇于临产前 (或 )临产后分别行胎心监护 ,以脐血流S/D值高于正常范围及胎心监护基线变异跳跃型和CST(OCT)出现晚期减速 (LD)或变异减速 (VD)作为判断胎儿预后和选择分娩方式的指标。结果 :脐带绕颈时脐动脉血流没受影响 ,脐动脉阻力不会升高 ,如果缠绕过多、过紧、相对脐带过短才会造成脐动脉血流障碍 ,导致阻力升高 ,这时脐血流S/D值才能反映出来。胎心监护出现跳跃型基线变异和CST(OCT)出现LD或VD ,胎儿窘迫、新生儿窒息的发生率明显增加。结论 :脐带绕颈对围产儿存在严重危害 ,应用脐血流预测脐带绕颈有一定的临床价值 ,同时应用胎儿监护仪对脐带绕颈者作产时监护可预测胎儿预后 ,对脐带绕颈分娩方式的选择有很大帮助。     

胎儿脐动脉,大脑中动脉及腹主动脉的血液频谱与脐动脉…

本文对３２例足月单胎正常妊娠的拟行择期剖宫产的初孕妇，于术前３０小时内，以彩色超声多谱勒测定胎儿脐动脉（ＵＡ），大脑中动脉及腹主动脉的血流频谱，即血流阻力指数，搏动指数，收缩期峰值与舒张末期值的比值。并于剖宫术胎儿娩出后取脐动、静脉血、测定ＰＨ、ＰＣＯ２及ＰＯ２，观察各种动脉血流频说与脐血血气间相关性。     

超声多普勒血流检测诊断胎儿脐带绕颈：附75例分析

本文应用超声血流分析仪对414例妊娠30—42w的孕妇进行了脐动脉血流检测,诊断脐带绕颈75例,经分娩证实72例,敏感性96%,特异性94.2%。本文还就胎儿颈部脐血流检测诊断脐带绕颈的部位进行了分析,提出胎儿颈部背、腹两侧皆有典型脐动脉血流波时敏感性、特异性最高,只有颈部腹侧有典型脐动脉血流波时敏感性,特异性最低。其次提出多普勒诊断胎儿脐带绕颈随孕周的增加准确性增加,多普勒诊断脐带绕颈的同时所检测脐动脉s/d比值可预测胎儿预后,特别是s/d比值连续升高时对推测脐带绕颈的松紧有所帮助,为临床选择恰当的分娩方式提供了更多指标,对降低围产儿死亡率有重要意义。     

胎盘造血功能的初步研究

目的 探讨胎盘在整个胎儿时期造血中的作用,寻找造血干／祖细胞的新来源,供临床移植应用。方法 分别测定脐动脉和脐静脉血中ＣＤ３４＾＋细胞,粒－巨噬泵细胞集落（ＣＦＵ－ＧＭ０及造智力在子含量,胎盘绒毛膜组织切片采用ＨＥ染色和ＣＤ３４单抗免疫组化染色。结果 脐静脉血中ＣＥ３４＾＋、ＣＤ３４＾＋／ＣＤ３８＾－细胞及ＣＦＵ－ＧＭ含量均高于脐动脉,脐静脉血中含有较多的造血刺激因子,而造血抑制因子的含量与肮动脉     

Doppler ultrasound measurements in the central circulation of anesthetized fetal sheep during obstruction of umbilical-placental blood flow.

OBJECTIVE: To establish by Doppler ultrasound the effects of acute blockage of umbilical cord vessels on the fetal central circulation. DESIGN: Experimental study in anesthetized pregnant sheep. METHODS: In 11 anesthetized pregnant sheep (0.66 of gestation), Doppler velocity profiles and/or venous flow rates were recorded in the ductus venosus, the fetal aorta, the umbilical arteries and the umbilical vein. This involved three phases. In Phase 1, the abdominal wall was closed (n = 9); Phase 2 was during fetoscopy after laparotomy (n = 8); Phase 3 was after coagulation of one of the umbilical arteries (n = 10). As an additional intervention in six fetuses, the umbilical cord was clamped for 5-15 s while blood flow velocity changes in the ductus venosus were observed. RESULTS: There were no significant differences between Doppler recordings in Phases 1 and 2. During Phase 3, the pulsatility index of the aorta and of the coagulated umbilical artery increased significantly. The umbilical vein blood flow rate was significantly reduced from a median of 408 (range, 243-575) mL/min/kg in Phase 1 to a median of 173 (range, 107-426) mL/min/kg in Phase 3, but the blood flow rate in the ductus venosus (median, 94; range, 56-148 mL/min/kg vs. median, 92; range, 33-237 mL/min/kg) remained unchanged. The ductus venosus/umbilical vein ratio increased from a median of 0.22 (range, 0.13-0.41) to 0.56 (range, 0.17-0.97) (P < 0.05). Compression of the cord (5-15 s) immediately reduced the time averaged maximum velocity in the ductus venosus from a mean of 51 (standard deviation, 11) cm/s to 20 (standard deviation, 6) cm/s (P < 0.001) without significant changes of the velocity profile. However, the pulsatility index increased from a mean of 0.55 (standard deviation, 0.19) to 1.89 (standard deviation, 0.73) (P < 0.001). CONCLUSION: Central venous flows in anesthetized fetal sheep are unaffected by laparotomy and hysterotomy. Obliteration of one umbilical artery increases the ductus venosus/umbilical vein volume flow (mL/min/kg) ratio. Compression of the umbilical cord shifts down blood flow velocity profiles in the ductus venosus, and the pulsatility index thus increases.     

Prenatal diagnosis of umbilical cord aneurysm in a fetus with trisomy 18.

Aneurysm of the umbilical cord is an extremely rare vascular anomaly. We report a case of umbilical cord aneurysm with arteriovenous fistula in a fetus with trisomy 18. At 34 weeks' gestation a fetus with suspected intrauterine growth restriction and oligohydramnios was referred to our institution. Ultrasound examination was confirmatory and additionally revealed multiple markers for trisomy 18. In the umbilical cord an aneurysm was diagnosed characterized by a cystic lesion with hyperechogenic rim measuring 18 x 18 x 19 mm in diameter. Color flow and spectral Doppler examinations showed a jet originating from one of the umbilical arteries entering the cystic lesion which appeared to be the dilated umbilical vein. Fetal blood sampling and subsequent karyotyping revealed trisomy 18 (47, XY, +18). The patient elected to terminate the pregnancy. Pathologic examination of placenta and umbilical cord confirmed the prenatal diagnosis of umbilical cord aneurysm and arteriovenous fistula. Histology demonstrated a strongly dilated umbilical vein, one moderately dilated artery and a second, apparently normal artery.     

Effect of bronchial blood flow on pulmonary artery wedge pressure with pulmonary embolism

Discrepancies between pulmonary artery wedge pressure (WP) and left atrial pressure (LAP) occur with pulmonary embolism. Theoretically, this discrepancy could be affected by the bronchial circulation or by the type of embolus. To test this in dogs, we determined the effects of embolism induced by glass beads and by air upon the WP with intact vs. ligated bronchial blood flow to the left lower lobe. For those animals receiving pulmonary air infusions, the pulmonary artery pressure, WP, and pulmonary vascular resistance showed significant (p less than .05) elevations with no change in LAP. There were no changes in these values when the bronchial blood flow was interrupted. When glass beads (120 mu) were injected into the left lower lobe, the pulmonary artery pressure and pulmonary vascular resistance rose as in the air emboli groups (p less than .05); however, WP remained at control values and approximated LAP. Obstructing the bronchial blood flow did not change this response. We conclude that the discrepancy between WP and LAP depends upon the type of embolus and is not affected by bronchial blood flow.     

胎儿脐静脉移植材料的应力松弛特性

背景：人脐静脉是动脉移植物的良好替代材料,在移植时除了考虑脐静脉与宿主动脉相匹配外,还应注意其顺应性. 目的：检测胎儿脐静脉近胎盘段和远胎盘段试样的应力松弛特性. 方法：取22-28岁、胎龄38-40周、自然分娩产妇的正常胎儿脐静脉近胎盘段和远胎盘段各10个试样,在电子万能实验机上进行应力松弛实验,在（36.5±0.5）℃的温度场下,以0.1%/s 的应变增加速度对试样施加应变,设定时间为7200 s.采集100个数据,采用归一化分析的方法计算两组试样的归一化应力松弛方程. 结果与结论：脐静脉近胎盘段组7200 s应力下降了0.275 MPa,脐静脉远胎盘段组7200 s应力下降了0.203 MPa,两组7200 s应力下降量差异有显著性意义（P〈0.05）.两组试样应力松弛曲线是以对数关系变化的,并且胎儿脐静脉近胎盘段和远胎盘段具有不同的应力松弛特性.     

Management of Acute Arterial Injuries

The most critical factor influencing the survival of an extremity with arterial injury is the time interval between injury and arterial repair.

The majority of arterial injuries from civilian trauma can be repaired by direct anastomosis. When a vascular replacement is needed, a plastic prosthesis or an autogenous vein graft is preferable to an arterial homograft.

An injured artery should be ligated only when the additional time required for arterial repair would jeopardize the life of the patient.     

Characteristics of blood flow in intrauterine growth-restricted fetuses with hypercoiled cord.

OBJECTIVE: To clarify the characteristics of fetoplacental blood flow of growth-restricted fetuses with hypercoiled umbilical cord. SUBJECTS: Eight growth-restricted fetuses with hypercoiled cord. METHODS: Flow velocity waveforms of the umbilical cord artery and vein, fetal abdominal aorta and fetal inferior vena cava were analyzed. RESULTS: The resistance index in the umbilical artery in the hypercoiled cases was lower than that in normal fetuses. Early-diastolic reversed flow was observed in the abdominal aorta in some cases. In all cases, umbilical venous pulsation was observed in the entire cord until delivery. In one case, fetal heart failure occurred, resulting in pre-mature delivery. An atrophic type of single umbilical artery was observed in four cases. CONCLUSION: Fetal blood flow disturbance caused by a hypercoiled umbilical cord may be a cause of growth restriction.     

Influence of route of hepatic administration on drug availability

The work investigates functional variability of hepatic arterial and portal venous streams in relation to drug availability. In an isolated rat liver system perfused in all experiments at a constant total flow of 10 ml X min-1, drug availability was found to be 18 and 3 times greater for lidocaine and meperidine, respectively, when infused through the hepatic artery compared to portal vein administration. When both hepatic artery and portal vein were perfused, drug availability increased log linearly for lidocaine, and linearly for meperidine with increasing hepatic artery flow contribution. Injection of 15-micron gamma-labeled microspheres into the hepatic artery and portal vein did not reveal arteriovenous or portovenous shunting channels greater than 15 micron in diameter. However, the ratios of the mean transit times of albumin and red blood cells were found to be significantly lower through the hepatic artery, indicating a possible reduction in perisinusoidal albumin space. When both hepatic artery and portal vein were perfused, linear correlations were obtained for values of this ratio plotted against increasing hepatic artery flow contributions. Data from the red blood cell transit time studies, as well as data on lidocaine availability, suggest the presence of functionally separate capillary beds for the hepatic arterial and venous streams.     

动脉机械性阻断致股骨头缺血性坏死的实验研究

目的　通过分别阻断股骨头主要供血血管 ,观测股骨头血流动态改变、血管再生及病理改变 ,为临床选择不同方法治疗股骨头缺血性坏死提供参考。方法　将实验兔旋股内、外侧动脉 ,根据不同组别分别结扎。于术后不同时间应用SPECT检测患侧头与健侧头、患侧头与干放射性计数比 ,半定量动态检测股骨头血流量及代谢的改变 ;拍X线平片 ,对股骨头墨汁染色切片 ,硬组织切片及荧光染色切片进行观察 ,并进行骨组织形态计量学检测 ,评价预后。结果　结扎旋股内、外侧动脉组及结扎旋股内侧动脉组的头 /头比及头 /干比明显下降 ,X平片示股骨头密度增高 ,切片荧光反映明显 ,骨组织形态计量学检测显示骨小梁结构紊乱 ,两组间无显著性差异 (P >0 0 5 ) ;结扎旋股外侧动脉组的头 /头比及头 /干比轻度下降 ,比值增高不显著 ,X线平片示股骨头无改变 ,切片荧光反映不明显 ,骨组织形态计量学检测显示骨小梁形态无明显变化 ,与前两组之间均有显著性差异 (P <0 0 5 )。墨汁染色切片示三组股骨头均有密集的血管 ,各组间无显著差异。结论　旋股内侧动脉及其分支为股骨头主要供血动脉 ;当股骨头血供受损严重 [(头 /头比 <0 7,(参考头 /干比 <1 8) ],并呈持续高代谢反应时 ,骨小梁承受应力能力差 ,后期出现塌陷可能性大