Die doppler-sonographische beurteilung der funktionsfähigkeit extra-intracranieller anastomosen

Zusammenfassung Wir berichten fiber die Doppler-sonographischen Ergebnisse bei 33 Patienten mit einer Anastomose zwischen der A. temporalis superficialis and der A. cerebri media. Die Indikation zur Bypass-Operation beinhaltete rezidivierende TIA oder ein kurz zuvor erworbenes leichtes neurologisches Defizit bei angiographischem Nachweis einseitiger oder beidseitiger tiefer Obliterationen der A. carotis interna und hochgradiger Stenosen oder Verschlüsse im distalen Abschnitt der A. carotis interna bzw. im proximalen Abschnitt der A. cerebri media. Die Funktionsfahigkeit der Anastomose wurde überpriift durch die Berechnung der modifizier ten Pourcelot-Indices (relative enddiastolische Strömungsgeschwindigkeit) der A. temporalis superficialis praeauriculär und am Bohrlochrand Bowie durch den EinfluB der intermittierenden Kompression des den Bypass-versorgenden Gefäßes auf den modifizierten Pourcelot-Index der ipsilateralen A. carotis communis. Bei allen Patienten mit funktionsfahigen Anastomosen, definiert durch einen modifizierten Pourcelot-Index von zumindest 0,20 am Bohrlochrand, kam es zu einer Reduktion dieses Parameters um durchschnittlich 0,08 an der A. carotis communis bei kurzfristiger Kompression des den Bypass-versorgenden Astes. Bei den 18 Patienten mit unilateraler Obliteration der A. carotis interna war der Bypass über-wiegend dann funktionsfähig, wenn die summierten modifizierten Pourcelot-Indices der verbliebenen hirnversorgenden Gefäße um zumindest 10% gegenüber einem vergleichbaren Normalkollektiv reduziert waren. Das Vorhandensein bzw. das Fehlen von Ophthalmica-Kollateralen hatte dabei keinen Einfluß auf den Prozentsatz der funktionsfahigen Anastomosen in diesen Untergruppen. Bei den vier Patienten mit bilateraler Obliteration der A. carotis interna war die angelegte Anastomose in jedem Fall funktionsfähig, während die Hälfte der Patienten mit Stenosen and Verschlüssen im distalen Abschnitt der Carotisstrombahn nur eine ungeniigende Bypass-Funktion zeigten. Die zwei Patienten mit einer Mediahauptstammstenose bzw. -obliteration hatten Indices von 0,45 bzw. 0,46 am Bohrlochrand als Hinweis auf die Funktionstüchtigkeit. Wir Bind der Auffassung, daß man mittels Doppler-sonographischer Kriterien die Funktionsfahigkeit einer Temporalis superficialis-Cerebri media-Anastomose überprüfen kann. Der praeoperativ berechnete summierte modifizierte Pourcelot-Index der verbliebenen hirnversorgenden Arterien kann zumindest bei uni- and bilateraler Internaobliteration als zusatzlicher Parameter herangezogen werden, um die Indikation zur Bypass-Operation zu klären.     

Die verwendung der autologen vena femoralis bei vena-cava-superior-thrombose

We report on a 52-year old male patient who underwent implantation of an insulin pump because he had diabetes and in whom superior vena cava syndrome developed as a long-term complication. After unsuccessful lysis therapy superficial femoral vein was implanted to form a bypass from the internal jugular vein to the right atrium. The postoperative course was uneventful from the aspects of both the bypass and the leg after explantation of the superficial femoral vein. The bypass is still patent 7 months after the operation, and the patient has no symptoms. Autogenous superficial femoral vein can be used successfully in the reconstruction of large venous vessels. It should be the graft of choice for young patients with benign diseases. We compare our result and those obtained with different substitutes described in the literature that have been used for reconstruction in superior vena cava syndrome.

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Die verwendung der autologen vena femoralis bei vena-cava-superior-thromboseFallbericht mit literaturübersicht

Zusammenfassung Bei einem 52jährigen, männlichen Patienten trat nach Implantation einer Insulinpumpe als Spätkomplikation eine Thrombose der Vena cava superior auf. Nach erfolgloser Lysetherapie wurde ein Venajugularis-rechtsatrialer-Venenbypass mit autologer Vena femoralis durchgeführt. Der postoperative Heilungsverlauf war sowohl von Seiten des gefäßrekonstruktiven Eingriffs, als auch von Seiten der Venenentnahmestelle komplikationslos. Der Bypass ist 7 Monate postoperativ offen und der Patient beschwerdefrei. Die autologe Vena femoralis eignet sich zur Rekonstruktion großer venöser Gefäße ausgezeichnet. Sie sollte v. a. bei benignen Prozessen und jüngeren Patienten als autologes Bypassmaterial dem Kunststoff vorgezogen werden. Das Ergebnis wird mit verschiedenen Gefäßsubstituten, die bei Verschluß der oberen Hohlvene verwendet werden, verglichen.

     

阿片受体对体外循环缺血再灌注损伤心肌的保护作用

目的 通过建立猪体外循环(CPB)心肌缺血再灌注(MI/R)模型对δ阿片受体激动剂脑腓肽(DADLE)介导的CPB MI/R损伤早期时相和后时相的心肌保护作用进行探讨,以期为临床心肌保护提供理论和实验依据.方法 将24只成年家猪随机分为对照组、早期时相和后时相组,每组8只常规建立CPB模型,主动脉阻断同时灌注改良St.Thomas停搏液.每组于CPB前、主动脉开放时、CPB结束时、停机后1、2 h检测冠状静脉窦血肌钙蛋白(TnT)含量,相应时间点监测左室舒张末期压(LVEDP)和左室内压最大变化速率(±ap/dt<,max>),于停机后2h取左心室心肌,进行心肌组织Gia蛋白的表达、PKC的表达和ATP含量的测定.并应用透射电镜观察心肌再灌注损伤超微结构的变化.结果 (1)和早期时相和后时相组相比,对照组心功能指标明显下降.(2)对照组的TnT较早期时相和后时相组明显升高,ATP含量明显降低.(3)和对照组相比,早期时相和后时相组Gin蛋白和PKC的表达更为明显.(4)透射电镜下早期时相和后时相组的心肌超微结构损伤均较对照组明显轻微.结论 (1)和CPB前1 h应用一次DADLE而产生的早期时相心肌保护作用相比,CPB前48 h和24 h两次应用DADLE引发的后时相心肌保护作用更为显著.(2)Gi蛋白-PKC途径可能是δ阿片受体介导的猪CPB NI/R损伤心肌保护中一条重要的信号传导途径.     

非体外循环冠状动脉搭桥术临床分析（附11例报告）

（1）目的 总结探讨11例非体外循环冠状动脉搭桥术（OPCAB）的经验。（2）方法 2001年6－12月对11例冠心患采用非体外循环心脏不停跳方法完成冠状动脉搭桥术。（3）结果 共搭桥35支，平均3．17支／例，其中左乳内动脉桥8支，大隐静脉桥27支。6例患（54．5％）未血，无手术死亡及并发症。（4）结论 非体外循环搭桥术克服了体外循环搭桥术（CABG）的诸多缺点和弊端，手术简化，时间缩短，适应证扩大，并发症明显减少，效果满意。     

Haemodynamic model of a unilateral iliac stenosis with an aortoiliac bypass

A hydrodynamic model for the part of the human arterial network below the renal arteries has been constructed using specially fabricated distensible tubes and a pulsatile pump to simulate an aortoiliac bypass. The experiments and the computer model indicated that no ‘steal’ occurred due to the insertion of the bypass graft. Also, the results showed that the length of the stenosis had a non-systematic apparent effect on the physiological significance of the obstruction and that the kinetic power represented only a small percentage of the total power. The total power efficiency of the bypass graft was unaffected by its elastic properties. The experimental investigation also indicated that the pressure drop across the stenosis was considerably larger than the drop calculated using the Poiseuille flow relationship when the stenosis was severe. Therefore, a critical arterial stenosis value cannot be defined as an obstruction of a constant percentage reduction of luminal area. It varies directly with the effective cross-sectional area and inversely with the flow rate. The value of angiography in assessing the functional significance of any arterial stenosis is there-fore limited. A better method for evaluation requires quantitative measurements of local blood pressure and blood flow, not only at rest, but also under conditions creating augmented flows due to exercise.     

Niedrig dosierte Acetylsalicylsäure (100 mg/Tag) nach aortokoronarer Bypassoperation

Summary A prospective, randomized, doubleblind, placebo-controlled trial was conducted to evaluate the efficacy of Acetylsalicylic Acid (ASS) (100 mg/d, starting 24 h after operation) on vein graft patency. Sixty of 88 patients having undergone surgery entered the study; in 24 of 31 patients in the placebo group and 22 of 29 patients in the ASS-group angiography was performed 4 months postoperatively. There were no significant differences between the groups with respect to age, number of diseased vessels or previous myocardial infarctions. Mean number of grafts per patient was 2,2 (placebo) and 1,8 (ASS) for proximal anastomoses (p<0.10) and 3.4 (placebo) and 2.6 (ASS) for distal anastomoses (p<0.05). Graft occlusion rate for proximal anastomoses was less in the ASS-group, 10% (4/40), as compared with placebo 32% (17/53) (p<0.05). Graft occlusion rate for distal anastomoses was also less in the ASS group, 19% (11/57) as compared to 35% (28/81) in the placebo group (p<0.10). All grafts were patent in 16/22 patients in the ASS group but only in 9/24 in the placebo group (p<0.05). On designation of patients without postoperative angiograms but cardiovascular events as well as those with at least one graft occluded as failures, the incidence of the latter was 9/29 in the ASS group and 20/31 in the placebo group (p<0.05). Early postoperative bleeding was similar in both groups, no side effects of ASS were observed. In this trial with initiation of low — dose ASS therapy 24 h after operation, antiplatlet therapy reduced the graft occlusion rate significantly.

Teile dieser Studie wurden auf der 49. Tagung der Deutschen Gesellschaft für Herz- und Kreislaufforschung in Mannheim im April 1983 [32] und auf der 89. Tagung der Deutschen Gesellschaft für Innere Medizin, Wiesbaden, April 1983 [18] vorgetragen. Mit Unterstützung der Deutschen Forschungsgemeinschaft     

The evaluation of intracranial bypass patency in neurosurgical practice

BackgroundThe patency of cranial bypasses must be carefully evaluated during and after the microsurgical procedure. Although, several imaging techniques are used to evaluate the patency of bypasses, their findings are sometimes difficult to interpret.PurposeThe goal of this study was to assess the consistency of different diagnostic modalities for evaluating intracranial bypass patency.Patients and methodThis prospective study included 19 consecutive patients treated with EC-IC or IC-IC bypass for MoyaMoya disease (MMD) or complex/giant aneurysms between June 2016 and June 2018. In the early postoperative period (< 7 days), all patients had transcranial Doppler (TCD), CT angiography (CTA) and MRA to demonstrate patency of anastomoses and to confirm exclusion of the aneurysm. When findings of anastomosis patency differed between these techniques, conventional angiography was performed.ResultsAll anastomoses were patent on indocyanine green videoangiography at the end of microsurgical procedure. The results of noninvasive postoperative exams were consistent to demonstrate the patency of anastomoses in 13 patients. In 4 patients, a discrepancy in patency of anastomoses arose between TCD, CTA and MRI in the early postoperative period. In 2 other patients, the interpretation of bypass patency remained inconclusive before the decision to occlude the aneurysm. In these 6 patients, a significant edema was noted in 2 cases, a postoperative subdural hematoma in 1 case, a low flow in the anastomosis in 1 case and vasospasm in 2 cases. The anastomosis was patent on the conventional angiography in five patients.ConclusionNoninvasive imaging techniques provide useful data about the patency but their findings should be carefully interpreted due to local anatomical, physiological, and pathological factors. In case of discrepant findings, conventional angiography including supraselective catheterization of the donor vessel is suggested.     

Viscoelastic properties of the autologous bypass grafts: A comparative study among the small saphenous vein and internal thoracic artery

Internal thoracic artery (ITA) and small saphenous vein (SSV) are two viable conduits for coronary artery bypass grafts. The aim of this study was to investigate the viscoelastic behavior of the small saphenous vein and internal thoracic artery under compressive and tensile loadings at body temperature. The dynamic mechanical analysis was used to measure the viscoelastic properties of the ITA and SSV at both the desired temperature and load frequency range. Storage modulus, loss modulus as well as phase angle of both the blood vessels were measured at the temperature of 37 ± 1 °C and under a sinusoidal load with the frequency range of 1–2 Hz. The mean storage and loss modulus of the SSV were both higher than that of the ITA. Furthermore, the SSV showed a higher stiffness and internal friction compared to those values under the tensile load. While ITA was stiffer under the tensile load, no considerable difference was observed among the compressive and tensile loss modulus. A more intense viscous behavior was observed under the radial direction. The results also revealed that the SSV has much higher stiffness whereas less viscous behavior compared to the ITA, especially in the radial direction. The results may have implications not only for understanding of the viscoelastic time-dependent mechanical behavior of the ITA and SSV but also for tissue engineering applications to make scaffolds according to the real time-dependent viscoelastic mechanical properties of these arteries and veins.