Journal of Theoretical and Applied Vascular Research最新文献_第9页

In memory of Prof. Dino De Anna 为了纪念迪诺·德·安娜教授

Journal of Theoretical and Applied Vascular Research Pub Date : 2018-06-30 DOI: 10.24019/jtavr.47

V. Gasbarro

引用次数: 0

In memory of Prof. Marco Apperti 纪念Marco Apperti教授

Journal of Theoretical and Applied Vascular Research Pub Date : 2018-06-30 DOI: 10.24019/JTAVR.44

G. Quarto, Antonio Sellitti

引用次数: 0

Invited commentary on 'The hypothesis of the toxic effects of the venous collateral circulation' by F Passariello. PTS, CCSVI-MS: Do intraparenchymal venous detours turn the blood toxic? 受邀评论F Passariello的“静脉侧支循环的毒性作用假说”。PTS, CCSVI-MS:肝实质内静脉绕道会使血液中毒吗?

Journal of Theoretical and Applied Vascular Research Pub Date : 2018-06-30 DOI: 10.24019/jtavr.40

F. Schelling

引用次数: 1

Dimensional analysis in the venous system 静脉系统的量纲分析

Journal of Theoretical and Applied Vascular Research Pub Date : 2018-06-30 DOI: 10.24019/JTAVR.25

F. Passariello

引用次数: 2

Contribution of the calf pump and foot pump to the return of venous blood from the lower extremity 小腿泵和足泵对下肢静脉血回流的贡献

Journal of Theoretical and Applied Vascular Research Pub Date : 2017-11-01 DOI: 10.24019/jtavr.43

C. Recek

{"title":"Contribution of the calf pump and foot pump to the return of venous blood from the lower extremity","authors":"C. Recek","doi":"10.24019/jtavr.43","DOIUrl":"https://doi.org/10.24019/jtavr.43","url":null,"abstract":"The anatomy and function of the calf pump and the foot pump as well as the interplay of their activity are described. The calf muscle pump constitutes an effective mechanism enhancing efficiently the return of venous blood toward the heart. During calf muscle contractions, the venous blood is ejected mainly into the popliteal vein, but a smaller part escapes through calf perforators into the saphenous system and streams further in the centripetal, i.e. physiological direction toward the heart. Calf muscle contractions induce marked increase in systolic pressure and calf muscle relaxations entail decrease of diastolic pressure both in deep and superficial veins of the lower leg. The systolic and diastolic pressure changes are produced in deep veins and are transmitted through calf perforators into the saphenous system, as documented by simultaneous pressure recordings in the posterior tibial and great saphenous veins. The systolic increase of pressure in the great saphenous vein is caused by the outward flow within calf perforators; competent valves in calf perforators would preclude any relevant pressure increase. Calf pump activity entails a distinct decrease of ambulatory venous pressure in lower leg veins, whereas in the thigh veins the pressure does not decrease; in this way, the ambulatory pressure gradient of 37.4 +6.4 mm Hg arises between thigh and lower leg veins and triggers the venous reflux in incompetent venous channels connecting both poles of the ambulatory pressure gradient. In contrast to the very efficient performance of the calf pump, the performance of the foot pump is hemodynamically unimportant. The ejection volume produced by the calf muscle pump comes at about 60 ml or more, whereas the blood volume ejected by the foot pump reaches a negligible value of 3-4 ml.","PeriodicalId":17406,"journal":{"name":"Journal of Theoretical and Applied Vascular Research","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90469946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Ambulatory venous pressure: new concepts 动态静脉压:新概念

Journal of Theoretical and Applied Vascular Research Pub Date : 1900-01-01 DOI: 10.24019/jtavr.105

S. Raju

{"title":"Ambulatory venous pressure: new concepts","authors":"S. Raju","doi":"10.24019/jtavr.105","DOIUrl":"https://doi.org/10.24019/jtavr.105","url":null,"abstract":"Background: The importance of the calf pump (the ‘peripheral heart’) in the lower limb venous circulation is well known. The ambulatory venous pressure (AMVP) is generally considered the quintessential functional test of calf pump function. However, much controversy exists on the basic hemodynamics of AMVP as well as its measurement. Recent work has helped to revise/clarify many of these controversies. Results from experimental simulations are used to illustrate key hemodynamic concepts. A multicameral model of calf pump Arnoldi popularized the notion that deep venous pressures can be monitored by inserting a needle in the dorsal foot vein (unicameral model). It has been shown recently that ambulatory venous pressures in the deep system is different from that in the dorsal foot vein and also the saphenous vein. AMVP profile in the three valved systems are different from each other (multicameral model). AMVP is traditionally monitored via % drop and also Venous refill time (VFT). Analysis of a large cohort of patients shows that VFT is more sensitive. % drop can be omitted as it is rare for it to be abnormal without concurrent abnormal VFT. AMVP is normal in venous obstruction, contradicting common belief. Ambulatory venous hypertension is a specific property of reflux, not obstruction. Supine venous pressure is elevated in obstruction but not reflux despite the suspected role of microvascular hypertension in reflux pathology. Role of calf capacitance & compliance: While severe reflux can shorten VFT, reduced calf capacitance and compliance are more important as can be shown in experimental set ups and clinical analysis. Calf Pump failure: Like the heart, the calf pump can eject all the inflow presented to it (up to 3X normal). Thus the popular concept of ‘calf pump failure’ from reflux overload has little concrete evidence to support it. Column segmentation: It is commonly assumed that valve closure results in column segmentation. It can be shown in experimental settings that collapse of the venous segment below the valve closure is necessary for column segmentation. Furthermore a reconstruction of the events surrounding column restoration makes it clear that a closed valve above the calf pump cannot reopen with the hydrostatic pressure of the restored column height below the closed valve alone. Much higher pressures generated by inflow interacting with wall tension of the infra-valvular segment is necessary to reopen the closed valve and restore flow. AMVP does not reach resting levels in experimental models till wall tension is restored to resting levels. A full blown reflux through an open valve will not transmit column pressure when the calf pump is partially collapsed. A non-invasive replacement for AMVP: Prevailing clinical practice and recent guidelines emphasize duration of reflux at the proximal saphenous, femoral and popliteal valves for assessment of reflux severity. It has been shown that these proximal valves play no significant role","PeriodicalId":17406,"journal":{"name":"Journal of Theoretical and Applied Vascular Research","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88378759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0