The Use of Stent Grafts for the Treatment of Aneurysms and Dissections of the Thoracic Aorta: A Single Centre Experience

OBJECTIVE: To review the results of stent graft treatment for diseases of the thoracic aorta. DESIGN: A retrospective study of the results of thoracic stent graft procedures in a single centre. METHODS: The results of 30 procedures performed in 24 patients were analysed. Eleven patients had aneurysmal dilatation of the descending thoracic aorta (>5.5 cm), nine patients had complicated type B dissection, three had penetrating ulcers and one had a traumatic pseudoaneurysm. Imaging follow-up consisted of CT scans performed at one, three, six and 12 months following the procedure and annually thereafter. RESULTS: One technical failure occurred due to a ruptured external iliac artery. There were no other immediate failures. The primary technical success rate was 83%. The 30-day procedural and patient mortality rates were 7 and 8%, respectively. No neurological complications occurred. Seven patients had the subclavian artery covered without complications. Secondary intervention was required in 21%. During the follow-up period (mean 11 months, range 1-48 months.) there were five deaths, two of which were related to stent graft infection. CONCLUSION: Thoracic stent grafts offer a realistic alternative to surgery.     

胰岛素抵抗性高血压大鼠α1肾上腺素受体亚型的改变

目的和方法：用高糖喂养复制胰岛素抵抗性高血压（ｉｎｓｕｌｉｎ－ｒｅｓｉｓｔａｎｔｈｙｐｅｒｔｅｎｓｉｏｎ，ＩＲＨ）大鼠模型，用放射配体结合实验和离体左心房及主动脉收缩功能实验，观察ＩＲＨ大鼠α１肾上腺素受体（α１－ａｄｒｅｎｏｃｅｐｔｏｒ，α１－ＡＲ）及其３种亚型在心脏和主动脉的改变。结果和结论：ＩＲＨ大鼠与同龄ＳＤ大鼠相比：（１）心脏α１－ＡＲ密度下降４８％（Ｐ＜００５），而介导的正性变力效应不变。（２）心脏α１－ＡＲ３种亚型占α１－ＡＲ总数的比例和在介导心脏正性变力效应中的作用表现为α１Ｂ－ＡＲ增加，α１Ｄ－ＡＲ减少，而α１Ａ－ＡＲ不变。（３）介导主动脉收缩的α１－ＡＲ及各亚型对激动剂的敏感性及最大收缩效应均无明显改变。     

Tunica media of aorta and pulmonary trunk in relation to internal calibres in transposition of great arteries,in aortic and pulmonary atresia and in normal hearts

Summary In a post mortem material of 17 cases of transposition of the great arteries (TGA) from patients with an age range from birth to two years and ten months after birth, the internal calibres of the great arteries and the ostia of the heart proved to be the same as in normal hearts. Furthermore, the media of the ascending aorta and pulmonary trunk showed no adaptation to the abnormal circulatory conditions in 15 cases of TGA with an age range from birth up to 51/2 months: in both great arteries the thickness of the tunica media and the packing density of its elastic fibres were the same as in normal hearts. However, adaptation of the tunica media of the pulmonary trunk to the abnormal circulatory conditions: increased media thickness, was found in the two remaining cases, older than 12 months.In 7 cases of pulmonary atresia (age from 1 day to 12 months) and in 9 cases of aortic atresia (age from 2 days to 37 days) the following observations were made. Vessels with reduced or absent function (ascending aorta in aortic atresia and pulmonary trunk in pulmonary atresia) showed a markedly different structure. In aortic atresia the internal calibre and thickness of the media of the ascending aorta were markedly reduced, whereas the packing density of the elastic fibres of the media remained the same as in normal hearts. In pulmonary atresia the pulmonary trunk showed large variations in internal calibre, whereas both media thickness and the packing density of its elastic fibres remained the same as in normal hearts. When the markedly enlarged single functional vessels (the pulmonary trunk in aortic atresia and the ascending aorta in pulmonary atresia) were compared no significant differences between their internal calibre, media thickness and the packing density of the elastic fibres were found indicating similar adaptation to the abnormal but comparable functional load of acting as sole arterial trunk.We are indebted to Prof. Dr. J. Moll for his help, to Dr. J.J. Willemse for statistical calculations, to Mr. P. Zondervan, M.D. (Dept. of Pathology I), for supply of material and to Mrs. L. Silvis for histo-technical assistance     

Non-invasive evaluation of abdominal aortic properties: lumped circuit model and estimation of its parameters

To non-invasively determine abdominal aortic properties, a five-element lumped circuit model was adopted. The model consists of resistance due to blood viscosity (R1), inertia of blood flow, compliances of the vessel (C1, C2), resistance of the peripheral arteries (R2) and the impedance of the femoral arteries (termination). Patterns of the central velocity of the upper abdominal aorta and the femoral artery are measured by pulsed Doppler echocardiography, and confours of flow volume rates are calculated. The pressure pattern of the lower limb is recorded by a pulse wave rransducer and corrected according to sphygmomanometer values. Contours are transformed into respective Fourier transform components. The current transfer function is described theoretically and calculated from the acquired Fourier components. Values of every element are evaluated by the nonlinear least squares method. In 94 subjects (17–92 years), the values of each element are estimated. R2 values are greater in the elderly group, than in the young group and r₁ (R1/cm) increased with age. This model demonstrates that vessel compliance (c₁+c₂ (C1+C2/cm)) decreases with age, and it is suggested that this may be a useful marker of arteriosclerosis.     

卡维地洛对高血压大鼠主动脉的保护作用

目的 :研究卡维地洛对核因子 κB(NF κB)、单核细胞趋化蛋白 1(MCP 1)在自发性高血压大鼠 (SHR)大血管中表达的影响 ,探讨其对血管保护的机制。方法 :18只雄性 12周龄SHR随机分为阳性组 ,卡维地洛组 ( 30mg/kg·d) ,美托洛尔组 ( 50mg/kg·d) ,灌喂 8周 ;另选同龄雄性WistarKyoto大鼠为阴性组 (n =6 )。用免疫组化法测各组主动脉NF κB、MCP 1的表达 ,ELISA法测血清MCP 1含量。结果 :与阴性组比较 ,阳性组主动脉组织中NF κB、MCP 1表达增加 (P<0 .0 1) ,且两者正相关 (r=0 .72 8,P <0 .0 1) ;血清MCP 1含量升高 1.6 4(P <0 .0 1)。 8周后 ,治疗组之间血压无明显差异 (P >0 .0 5) ,但卡维地洛更显著抑制NF -κB、MCP 1表达 (P <0 .0 5)。结论 :卡维地洛可能独立于降压外抑制NF κB的活化来调控MCP 1表达。     

Calcification of the human thoracic aorta during aging

The rate of calcification within the human thoracic aorta from completion of body growth to advanced old age was examined. Fifty-eight aortae, obtained at necropsy, were dissected into four layers: the complete intima and the separated media, which was subdivided into three tissue samples of equal thickness, defined as the media-inner,-middle, and-outer layers. The sampling sites selected for analysis were from regions of the aortic surface that were free of atherosclerotic plaques. The calcium content within each tissue layer of the aorta was determined. Arterial wall thickness and the cholesterol content of the four layers were also measured. Intimal calcification increased progressively during aging: from 1.6 g Ca/mg tissue at 20 years of age to 5.2 g Ca/mg tissue by 90 years of age. When intima calcium concentration was expressed by tissue volume (w/v), no significant change during aging was found. Medical calcification, as w/v and by w/w, increased throughout aging. Calcium accumulation was most marked in the middle, elastin-rich layer of the media, increasing from 1.4 g Ca/mg tissue at 20 years of age to 49.50 g Ca/mg tissue by 90 years of age. Calcium levels also increased in the other media layers, but at a slower rate then that found within the middle media.     

Effects of angiopeptin on transplant arteriosclerosis in the rat

The influence of the somatostatin analogue angiopeptin on transplant arteriosclerosis was investigated using two aortic transplantation rat models. One was characterized by ischemia/reperfusion-induced changes in syngeneic transplants while immunologically induced changes dominated in the other allogeneic model. Angiopeptin, 100 g/kg per day, was administered continuously until the sacrifice of the rats after 8 weeks. No additional immunosuppression was used in either model. An image analysis system was used to quantify the intimal and medial thicknesses of the grafts. In the syngeneic grafts, the intimal thickness was less than 50% of that of control grafts (P<0.05), but no difference was seen in the allogeneic model. The expression of selected cells, TGF-s and PDGF and PDGF -receptors was detected immunohistochemically and displayed a similar picture in control and angiopeptin-treated grafts in both models. We conclude that angiopeptin has no clear immunosuppressive properties but may counteract ischemia-induced transplant arteriosclerosis.Part of this paper has previously been published in Transplant Proceedings (1993; 21: 2098–2099).     

腹主动脉缩窄性高血压大鼠心脏原生型一氧化氮合酶基因表达及 L-精氨酸的作用

目的　观察腹主动脉缩窄性高血压大鼠早期心脏原生型一氧化氮合酶基因表达及 Ｌ精氨酸对血压的影响。方法　１４ ～１６ 周龄雄性 Ｗｉｓｔｅｒ 大鼠采用缩窄腹主动脉法制备高血压模型,口服 Ｌ精氨酸（ 精氨酸组） 和未服 Ｌ精氨酸（ 手术组） 的高血压大鼠及正常血压大鼠（ 对照组） 在同样条件下喂养２ 周后,测量血压,并采用逆转录多聚酶链反应技术检测一氧化氮合酶基因表达。结果　①大鼠腹主动脉缩窄后发生严重的高血压且心脏一氧化氮合酶基因表达增强;②口服 Ｌ精氨酸２ 周未能防止腹主动脉缩窄性高血压的发生。结论　腹主动脉缩窄性高血压大鼠早期心脏一氧化氮合酶基因表达增强; Ｌ精氨酸的降压作用可能具有选择性。     

Etidronate (EHDP) Inhibits Osteoclastic-Bone Resorption, Promotes Apoptosis and Disrupts Actin Rings in Isolate-Mature Osteoclasts

Bisphosphonates, therapeutic reagents against tumoral bone diseases (Paget's disease or osteoporosis), are potent inhibitors of bone resorption. The mechanisms by which they directly act on mature osteoclasts remain unclear. Using a recently developed technique for isolation of highly purified mammalian mature osteoclasts, we demonstrated that etidronate [ethane-1-hydroxy-1,1-diphosphonate (EHDP), 1-hydroxy-1,1-ethylidenebisphosphonate], inhibited directly osteoclastic bone-resorbing activity by pit assay. In addition, EHDP also directly induced apoptosis and disrupted actin rings in osteoclasts. The data support previous data on non-purified osteoclasts and results in vivo. Received: 26 June 1997 / Accepted: 27 July 1998     

Analysis of the action of idazoxan calls into question the reliability of the rat isolated small mesenteric artery assay as a predictor for α1-adrenoceptor-mediated pressor activity

We have studied the effects of idazoxan in rat aorta and small mesenteric artery. In the aorta, idazoxan behaved as a partial agonist (pK_A=6.30). Prazosin produced rightward shift (pA₂=9.88) and steepening of the idazoxan curve. In contrast, idazoxan had no effect of basal tension in the mesenteric artery, but shifted the noradrenaline curve to the right in a parallel manner (pA₂=6.12). The selective al-adrenoceptor agonist, indanidine, also behaved as a partial agonist in the aorta and produced no significant contractions of the small mesenteric artery. Since idazoxan and indanidine have been reported to raise blood pressure in the pithed rat via an action at vascular ₁-adrenoceptors, these results call into question the reliability of the small mesenteric artery assay as a predictor for ₁-adrenoceptor-mediated pressor activity in vivo.