Saphenous vein valve assessment utilizing upright CT to potentially improve graft assessment for bypass surgery.

Saphenous veins (SVs) are frequently employed as bypass grafts. The SV graft failure is predominantly seen at the valve site. Avoiding valves during vein harvest would help reduce graft failure. We endeavored to detect SV valves, tributaries, and vessel size employing upright computed tomography (CT) for the raw cadaver venous samples and in healthy volunteers. Five cadaver legs were scanned. Anatomical analysis showed 3.0 (IQR: 2.0-3.0) valves and 13.50 (IQR: 10.00-16.25) tributaries. The upright CT completely detected, compared to 2.0 (IQR: 1.5-2.5, p = 0.06) valves and 9.5 (IQR: 7.5-13.0, p = 0.13) tributaries by supine CT. From a total of 190 volunteers, 138 (men:75, women:63) were included. The number of valves from the SF junction to 35 cm were significantly higher in upright CT than in supine CT bilaterally [upright vs. supine, Right: 4 (IQR: 3-5) vs. 2 (IQR:1-2), p < 0.0001, Left: 4 (IQR: 3-5) vs. 2 (IQR: 1-2), p < 0.0001]. The number of tributaries and vessel areas per leg were also higher for upright compared with supine CT. Upright CT enables non-invasive detection of SV valves, tributaries, and vessel size. Although not tested here, it is expected that upright CT may potentially improve graft assessment for bypass surgery.

Morphology of the Vieussens valve and its imaging in cardiac multislice computed tomography.

INTRODUCTION: To deliver accurate morphological descriptions of the Vieussens valve (VV) and to investigate whether this structure could be visualized using standard contrast-enhanced electrocardiogram-gated multislice computed tomography (MSCT). METHODS: A total of 145 human autopsied hearts and 114 cardiac MSCT scans were examined. RESULTS: The VV was observed in both study groups, however, the detection rate was significantly worse in the MSCT examination (18.4% in MSCT vs 62.1% in cadavers, P < .0001). The VV height was larger in MSCT patients (2.8 ± 1.2 vs 5.4 ± 1.7 mm; P < .0001). No significant difference was found in the measured distance between the VV and the coronary sinus ostium between the two separate subgroups (27.3 ± 9.5 vs 24.4 ± 5.8 mm; P = .18). In autopsied material the most frequent valve location was the anterior wall of the coronary sinus (43.3%); the same was observed in MSCT scans (71.4%). CONCLUSION: The VV is a common heart structure, present in over 60% of humans, located mainly on the anterior and superior circuit of the coronary sinus, with relatively high morphological variability. Large VVs, which pose a significant obstacle in catheterization procedures, may be visualized using standard-protocol contrast-enhanced cardiac MSCT.

Human Femoral Vein Diameter and Topography of Valves and Tributaries: A Post Mortem Analysis.

The femoral vein (FV) is a clinically important vessel. Failure of its valves can lead to chronic venous insufficiency (CVI) with severe manifestations such as painful ulcers. Although they are crucial for identifying suitable implant sites for therapeutic valves, studies on the topography of FV tributaries and valves are rare. Moreover, the femoral vein diameter (FVD) must be known to assess the morphometric requirements for valve implants. To reassess the anatomical requirements for valve implants, 155 FVs from 82 human corpses were examined. FVDs and tributary and valve topographies were assessed using a laboratory straightedge. The FVD increased from 6 mm in the distal femoropopliteal vein to 11 mm in the iliofemoral vein proximal to the saphenofemoral junction (SFJ). Diameters were significantly bigger in males than females. Height correlated positively with FVD. Distal to the SFJ, within a distance of 38 cm, one to eight valves were present. Up to two valves were present within 10 cm proximal to the SFJ. Individual tributary and valve topography must be considered to ensure appropriate design and successful implantation of a venous valve for CVI therapy in the FV. A suitable implant site would be proximal to the SFJ via an infrainguinal transfemoral access. Clin. Anat. 31:1065-1076, 2018. © 2018 Wiley Periodicals, Inc.

Variation of anatomical structures related to biventricular pacing procedures and cannulation of the coronary sinus.

The success of biventricular pacing procedures is at least partially related to the ability to implant leads into the heart. Lead placement into the coronary sinus can be particularly challenging because of variations in the coronary venous anatomy. We examined the anatomy of the coronary sinus and the Thebesian valve. Forty-three (22 male, 21 female) embalmed adult cadavers were used to determine the internal diameter of the coronary sinus ostium, the presence of a membranous or fenestrated Thebesian valve, and the percent occlusion of the coronary sinus ostium by the Thebesian valve, if present. An 8-French (F) guiding catheter was used to simulate coronary sinus cannulation. The average internal diameter of the coronary sinus ostium was 11.44 ± 3.21 mm. A Thebesian valve was present in 74 % of the cadavers, and the majority (84 %) of those valves were membranous. In the presence of a Thebesian valve, the opening at the ostium was reduced to 7.47 ± 2.69 mm. The percent occlusion of the coronary sinus ostium by the Thebesian valve varied from 8.26 to 100 %. The average cannulation distance (length of catheter travel into the coronary sinus from the coronary sinus ostium) was 69 ± 18 mm. Statistical analyses revealed no gender differences in the measurement data for either the coronary sinus or Thebesian valve. The most common presentation is a membranous Thebesian valve. Most frequently, the percent occlusion ranged between 41 and 50 %. The cannulation distance was greater in males than in females.

Venous Valvular Distribution in the Thoracic and Pelvic Limbs of the Horse.

Dysfunction of venous valves can lead to hemodynamic disorders causing venous stasis, which would favour the occurrence of equine laminitis. However, very few studies have investigated venous valves in the horse digit. The purpose of this study was to compare valvular density between thoracic and pelvic limbs and to study the relationship between valvular density of veins and their location, diameter and wall thickness. After dissection, valvular density was calculated based on the number of valves counted in the principal veins of 7 thoracic and 7 pelvic limbs from 7 horses. Our results showed that the valvular density was higher in thoracic limbs, which probably reflects the adaptation to the consequences of hydrostatic pressure. The superficial veins have a higher valvular density that would prevent the varicose risk in the horse. The lower valvular density in the thick veins can be explained by the high density of the smooth muscular cells contained, which would cause an important vasoconstriction via the sympathetic nervous system. The veins with a large diameter also have a lower valvular density; these veins are not exposed to important changes in hydrostatic pressure. Other valvular characteristics may also be involved in the vascular disorders that may be related to the pathophysiology of laminitis.

Válvula en la vena renal izquierda. Historia de un hallazgo poco conocido / Valve in the left renal vein: History of a little known finding

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Anatomical variations of the coronary sinus valve (Thebesian valve): implications for electrocardiological procedures.

AIMS: The Thebesian valve (TV) can be a significant obstacle to coronary sinus (CS) cannulation. The aim of this study was to evaluate the characteristic features of the CS valve--TV anatomy. In particular, emphasis was placed on identifying specific structures of the TV that could potentially complicate CS cannulation. METHODS AND RESULTS: We examined 273 autopsied human hearts. The height of the TV and the diameter of the CS were measured. The valves were classified according to their shape into five types: remnant, semilunar, fold, cord, and mesh and fenestrated. The mean transverse CS ostium (CSO) diameter was 12.2 ± 3.5 mm. The TV was present in 224 (82.1%) cases. The most common type of TV was semilunar: 32.6%; followed by remnant: 25.5%; fold: 17.4%; cord: 14.3%; and lastly mesh and fenestrated: 10.3%. The mean TV height for remnant-semilunar-fold types was 5.8 ± 3.0 mm. In seven cases, the present TV (2.6%) covered the entire orifice of the CS. Hearts with larger CSO diameter had lower TV height (P < 0.001). CONCLUSIONS: We propose a new classification of the TV shapes based on the largest sample to date. We assessed that only in 2.6% of all 273 cases the presence of an obstructive TV can cause unsuccessful cannulation. The height of the TV was inversely correlated to the CSO diameter (r = -0.33; P < 0.001).

Distribution of saphenous vein valves and its pratical importance / Distribuição das válvulas da veia safena magna e sua importância prática

Objective: Among the veins used as a graft in myocardial revascularizations and ends, great saphenous vein is the most used. Knowing the presence and location of valves has great importance when evaluating the surgical anatomy of the great saphenous vein. Despite major surgical application and many works involving great saphenous vein, the number of valves present in it from the saphenous hiatus to the medial epicondyle of the femur is still described inaccurately. The objective of this study is to quantify the valves of the great saphenous vein from the saphenous hiatus to the medial epicondyle of the femur to determine the best portion of the great saphenous vein to perform revascularization surgeries. Methods: This is a crosssectional observational study in which it was analyzed great saphenous vein extracted from 30 cadavers. It was measured the length of the veins; (diameter) at its proximal, middle and distal, quantifying the number of valves in each one and the total number of valves at the great saphenous vein. Results: The frequency of valves in the great saphenous vein taken from the medial epicondyle of the femur to the saphenous hiatus was 4.82, ranging between 2 and 9. Moreover, there is a significant difference in the number of valves in the proximal and distal relative to the average. Conclusion: the median and distal portions of the saphenous vein in the thigh, are the best options for the realization of bridges due to the fact that these portions have fewer valves which therefore would tend to decrease the risk of complications connected with the valves in these grafts. .

Objetivo: Dentre as veias empregadas para revascularizações do miocárdio e de extremidades, a veia safena magna é a mais utilizada. Conhecer a presença e localização de válvulas é de grande importância quando se avalia a anatomia cirúrgica da veia safena magna. Apesar de grande aplicação cirúrgica e de muitos trabalhos envolvendo a veia safena magna, o número de válvulas presente nela desde o hiato safeno até o epicôndilo medial do fêmur ainda é descrito de forma imprecisa. O objetivo do presente trabalho é quantificar as válvulas da veia safena magna desde o hiato safeno até o epicôndilo medial do fêmur para determinar a melhor porção da veia safena magna para a realização de cirurgias de revascularização. Métodos: Este é um estudo transversal e observacional em que foram analisadas veias safena magna extraídas de 30 cadáveres. Foram realizadas as medidas das variáveis do comprimento das veias; (diâmetro) em suas porções proximal, média e distal; quantificação do número de válvulas nestas e número de válvulas total na veia safena magna. Resultados: A frequência de válvulas da veia safena contadas desde o epicôndilo medial do fêmur até o hiato safeno foi de 4,82, podendo variar entre 2 e 9. Além disso, houve diferença significante do número de válvulas da porção proximal em relação à média e distal. Conclusão: As porções média e distal da veia safena magna na coxa são as melhores opções para a realização de pontes em decorrência do fato destas porções terem menor quantidade de válvulas o que, portanto, tenderia a diminuir o risco de complicações relacionadas as válvulas nestes enxertos. .

Arcus venosus dorsalis pedis: morphological considerations for use in superficial palmar arch reconstruction.

PURPOSE: To report the branching patterns, vessel diameters, and location of the valves in the arcus venosus dorsalis pedis (AVDP) as a graft option for use in superficial palmar arch reconstruction after mutilating hand injuries. METHODS: We dissected 10 cadaveric feet and measured vessel diameters, recorded number of branches, and located valves within the tibial, middle, and fibular thirds of the system. We used retrograde india ink injection to locate valves. RESULTS: The AVDP branching pattern was grossly different from side to side in the 4 cadavers with bilateral feet available. Mean flat diameters were 4.7, 2.9, and 2.1 mm in the tibial, middle, and fibular thirds of the arch, respectively. There was a mean of 1.7 valves (range, 1-4 valves) in the tibial third, 1.5 valves (range 0-4 valves) in the middle third, and 0 valves in the fibular third. There was an average of 3.4 branches off the middle third with a mean branch diameter of 2.1 mm. In 65% of these branches, valves were within 1 cm distal to the main arch. The direction of flow within the middle third was from fibular to tibial. CONCLUSIONS: Valves were commonly found within the middle and tibial thirds of the AVDP and within branches just distal to bifurcations. By contrast, the fibular third of the AVDP contained no valves. Valvular anatomy suggests that the direction of flow within the middle third was from fibular to tibial direction. CLINICAL RELEVANCE: The AVDP is morphologically similar to the palmar arch. When rendering valves within the AVDP incompetent, attention should be paid not just to the main arch itself, but also to branches off the AVDP. The fibular and middle thirds of the AVDP can safely be used for palmar arch reconstruction without blockage of flow owing to valves. The branches off the middle third must be used within a few millimeters of their takeoff to avoid valves.

Distribution of saphenous vein valves and its practical importance.

OBJECTIVE: Among the veins used as a graft in myocardial revascularizations and ends, great saphenous vein is the most used. Knowing the presence and location of valves has great importance when evaluating the surgical anatomy of the great saphenous vein. Despite major surgical application and many works involving great saphenous vein, the number of valves present in it from the saphenous hiatus to the medial epicondyle of the femur is still described inaccurately. The objective of this study is to quantify the valves of the great saphenous vein from the saphenous hiatus to the medial epicondyle of the femur to determine the best portion of the great saphenous vein to perform revascularization surgeries. METHODS: This is a cross sectional observational study in which it was analyzed great saphenous vein extracted from 30 cadavers. It was measured the length of the veins; (diameter) at its proximal, middle and distal, quantifying the number of valves in each one and the total number of valves at the great saphenous vein. RESULTS: The frequency of valves in the great saphenous vein taken from the medial epicondyle of the femur to the saphenous hiatus was 4.82, ranging between 2 and 9. Moreover, there is a significant difference in the number of valves in the proximal and distal relative to the average. CONCLUSION: the median and distal portions of the saphenous vein in the thigh, are the best options for the realization of bridges due to the fact that these portions have fewer valves which therefore would tend to decrease the risk of complications connected with the valves in these grafts.

Applied Anatomy of the Femoral Veins in Macaca fascicularis / Anatomía Aplicada de las Venas Femorales en Macaca fascicularis

The aim was to understand the anatomical features of the venous valve in Macaca fascicularis and to compare it with that of humans. The bilateral lower limbs (24 limbs from 12 animals) of Macaca fascicularis cadavers were dissected, and the femoral veins (FVs) were equally divided into distal, intermediate, and proximal sections. The external diameter of the FV in each section was measured. The venous valves were observed microscopically and stained with hematoxylin and eosin as well as trichrome. Data describing the human venous valve were collected from the current literature. No great saphenous veins were found among the 24 lower limbs from the Macaca fascicularis cadavers. The external diameters of the FVs in the distal, intermediate, and proximal sections were 3.53 ± 0.37 mm, 3.42 ± 0.55 mm, and 3.37 ± 0.54 mm, respectively. In most cases, there was one venous bivalve located in the FV approximately 0-2.71 mm below the junction of the FV and the deep femoral vein. Endothelium covered the luminal and sinusal surfaces of the leaflets. Abundant collagen fibers were found under the endothelial cells beneath the luminal surface of the leaflets. An elastin fiber network was located under the sinus endothelial surface. Smooth muscle cells in the FV extend to the edge of the valve. The venous valve of Macaca fascicularis is similar to that of humans, both morphologically and histologically. However, there is only one venous bivalve and no great saphenous vein in Macaca fascicularis.

El objetivo fue comprender las características anatómicas de la válvula venosa en Macaca fascicularis y compararla con la de los humanos. Fueron disecados bilateralmente los miembros pélvicos (24 miembros de 12 animales) de cadáveres de Macaca fascicularis; las venas femorales (VF) fueron divididas en secciones distal, media y proximal. Se midió el diámetro externo de las VFs en cada sección. Las válvulas venosas se observaron microscópicamente y se tiñeron con H-E y tricrómico. Los datos para describir la válvula venosa humana se obtuvieron desde la literatura. No se encontraron venas safenas magnas entre los 24 miembros inferiores. Los diámetros externos de las VFs en las secciones distal, media y proximal fueron 3,53±0,37 mm, 3,42 mm±0,55, y 3,37±0,54 mm, respectivamente. En la mayoría de los casos, hubo vena bivalva situada aproximadamente 0-2,71 mm debajo de la unión de la VF y la vena femoral profunda. El endotelio cubrió las superficies luminal y sinusal. Se observaron abundantes fibras de colágeno en las células endoteliales bajo la superficie luminal de las válvulas. Una red de fibras de elastina se encontró bajo la superficie del seno endotelial. Las células musculares lisas en las VFs se extiendían hasta el margen de la válvula. La válvula venosa del Macaca fascicularis es similar a la de los seres humanos, morfológica e histológicamente. Sin embargo, sólo hubo una vena bivalvular, y no se observaron venas safenas en Macaca fascicularis.

The ostial valve of the great saphenous vein.

BACKGROUND: Venous valves have been classified into parietal (PVs) and ostial valves (OVs). PVs are located within the lumen of veins, whereas the OVs are located directly at the confluence of two veins. In the common femoral vein (CFV), the most prominent PVs are the suprasaphenic and infrasaphenic valve. The terminal valve (often designated as 'valvule ostiale' in the relevant literature in French) defined as that lying between the orifice of the great saphenous vein (GSV) and the most proximal of the major superficial tributary veins and the preterminal valve represent the most important PVs in the GSV. While PVs are well studied, there is not much literature on the OVs of the superficial venous system, especially of the GSV. OBJECTIVE: In order to investigate the presence of OVs (defined strictly as valves located at the entrance of a tributary vein) in the GSV, we carried out studies on specimens obtained from bodies bequested to the Division of Clinical and Functional Anatomy of Innsbruck Medical University. METHODS: Ninety-eight specimens consisting of the CFV and the attached tributary veins including the GSV were investigated. RESULTS: In five of these (5.1%), a single-cusped OV, in six (6.1%) a two-cusped OV and in 10 (10.2%) remnants of an OV were identified. Thus, OVs do not seem to be primarily present in all GSVs. CONCLUSION: The distinction between PVs and OVs is not always clear in literature, and as a consequence misinterpretations may occur. Very often the terminal valve of the GSV, which is in fact a PV, is designated as an 'ostial valve'. In view of its widespread use, we suggest that the term 'ostial valve' together with its clear description be included in the consensus documents of the 'Union Internationale de Phlébologie'.

The vertebral venous plexuses: the internal veins are muscular and external veins have valves.

The internal and external vertebral venous plexuses (VVP) extend the length of the vertebral column. Authoritative sources state that these veins are devoid of valves, permitting bidirectional blood flow and facilitating the hematogenous spread of malignant tumors that have venous connections with these plexuses. The aim of this investigation was to identify morphologic features that might influence blood flow in the VVP. The VVP of 12 adult cadavers (seven female, mean age 79.5 years) were examined by macro- and micro-dissection and representative veins removed for histology and immunohistochemistry (smooth muscle antibody staining). A total of 26, mostly bicuspid, valves were identified in 19 of 56 veins (34%) from the external VVP, all orientated to promote blood flow towards the internal VVP. The internal VVP was characterized by four main longitudinal channels with transverse interconnections; the maximum caliber of the longitudinal anterior internal VVP veins was significantly greater than their posterior counterparts (P < 0.001). The luminal architecture of the internal VVP veins was striking, consisting of numerous bridging trabeculae (cords, thin membranes and thick bridges) predominantly within the longitudinal venous channels. Trabeculae were composed of collagen and smooth muscle and also contained numerous small arteries and nerve fibers. A similar internal venous trabecular meshwork is known to exist within the dural venous sinuses of the skull. It may serve to prevent venous overdistension or collapse, to regulate the direction and velocity of venous blood flow, or is possibly involved in thermoregulation or other homeostatic processes.

Position of valves within the subclavian and axillary veins.

BACKGROUND: The aim of this explorative morphologic study was to determine the position and frequency of the valves in the axillary and subclavian veins. METHODS: The position and frequency of the valves in the subclavian and axillary veins were studied macroscopically in 59 limbs from 30 cadavers. We measured in situ with a measuring tape, starting from the venous angle toward the initiation of the axillary vein. All cadavers were bequeathed by informed consent. RESULTS: A terminal valve existed in all subclavian veins within the range of 0.0 to 27.5 mm (mean: left, 13.87 mm; right, 9.78 mm) distally to the venous angle; a second valve existed in one left and one right subclavian vein at a distance of 30.0 and 30.5 mm, respectively. All left axillary veins had a "most proximal" valve (mean, 103.4 mm), 73.3% also possessed a second valve (mean, 140.48 mm), and 16.7% had a third valve (mean, 153.9 mm). All right axillary veins possessed at least one valve (mean, 100.07 mm), 75.86% had a second valve (mean, 134.55 mm), 34.48% also had a third valve (mean, 157.30 mm), and 10.3% had a fourth valve (mean, 140.0 mm). CONCLUSIONS: All of the axillary and subclavian veins in our specimens possessed at least one valve. All the valves in the subclavian veins were concentrated to the proximal half, resulting in a valveless distal half. The subclavian vein rarely had a second valve. The valves in the axillary veins were located in the distal half, resulting in a valveless proximal half. The axillary vein can have one to four valves. No relation was evident between the frequency of the valves and the age of the donors when they died. Many other factors may influence the frequency of the valves in the axillary vein.

Number and location of venous valves within the popliteal and femoral veins: a review of the literature.

Although deep venous insufficiency is common and important, the anatomy of deep vein valves is poorly understood. The aim of this study was to investigate the location, number and consistency of venous valves in the femoral and popliteal veins in normal subjects. A detailed literature search of PubMed was performed. Abstracts and selected full text articles were scrutinised and relevant studies published between 1949 and 2010 reporting anatomical details of deep vein valves were included. From 7470 articles identified by the initial search strategy, nine studies with a total of 476 legs were included in this review. All studies were cadaveric and subjects ranged from stillborn fetuses to 103 years of age. Studies suggested that femoral veins contain between one and six valves, and popliteal veins contain between zero and four valves. Deep vein valves were consistently located in the common femoral vein (within 5 cm of the inguinal ligament), the femoral vein (within 3 cm of the deep femoral vein tributary) and in the popliteal vein near the adductor hiatus. Valves are consistently located at specific locations in the deep veins of the leg, although there is often significant variability between subjects. Further anatomical and functional studies using new imaging modalities available should target these areas to identify whether certain valves play a more important role in venous disease. This may guide us in the development of new treatment options for patients with deep venous disease.

Ophthalmic and facial veins are not valveless.

BACKGROUND: The ophthalmic and facial veins are frequently stated to be devoid of valves, facilitating the spread of infection from the mid-face to the cavernous sinus. METHODS: Twelve superior and eight inferior ophthalmic veins together with 13 angular and facial veins were harvested from adult cadavers. Each vein was opened longitudinally and examined by stereomicroscopy; the number, location and geometry of valve cusps were recorded. RESULTS: Ten valves were identified in nine (75%) superior ophthalmic vein specimens: four valves were in the superior ophthalmic vein and the remainder were located near its origin from angular and supra-orbital tributaries. No valves were seen in the inferior ophthalmic vein. Seventeen bicuspid valves were identified in tributaries of the angular vein or in the facial vein, but none were in the angular vein itself. Four of seven facial vein segments extending to the lower border of the mandible had valves. The orientation of valve cusps predicted the following blood flow: in the facial vein, inferiorly; in the superior ophthalmic vein, towards the cavernous sinus; and in the angular vein, to the facial or superior ophthalmic vein. CONCLUSIONS: This study demonstrates, for the first time, the existence of valves in the superior ophthalmic vein and its two main tributaries. Valves were also seen in the facial vein. It is not the absence of venous valves but the existence of communications between the facial vein and cavernous sinus and the direction of blood flow that is important in the spread of infection from the face.

The valvular segment of the lower limbs venous system: anatomical, physiological and physiopathological aspects.

The valvular segment is a distinct venous structure, which, from a morphological point of view, is comprised of the following components: the valvular insertion, the valvular gorge entrance orifice, the valvular defile, the valvular gorge exit orifice, the valvular sinus. Endoscopic and echo Doppler examinations are used to identify the normal and the pathological morphology of the valvular segment, and the hemodynamic phenomena occurring at this level. Cusps' integrity and size as well as valvular dynamics are key elements directly involved in shaping the valvular segment in general, and the valvular sinus in particular. The valvular sinus shows an obvious hemodynamic determinism. Valvular segment pathology is the outcome either of a progressively long evolving process initialized by gravitational venous pressure overcharges, or of a rapidly evolving process such as the hemodynamic shock following intense physical efforts. Valvular defunctionalisation implies a different mechanism and a different type of cusp lesion.

Internal jugular vein valves: an assessment of prevalence, morphology and competence by color Doppler echography in 240 healthy subjects.

The presence of valves in the head and neck veins is known since classical anatomical dissections. Previous studies have investigated whether jugular veins show constant valves at their ostium and whether these valves are physiologically competent, but, unluckily, these studies have reported conflicting results. Further, recent observations have raised the question whether the incompetence of jugular vein valves might play a pivotal role in neurological disorders related to venous engorgement of the brain. In this study we examined 462 internal jugular veins by using an echocolorodoppler apparatus. In particular, we assessed the presence, morphology and competence of valves at their ostium. Unilateral jugular vein valves were present in 406 cases (88%), mainly on the right side. The most frequently observed morphology (75%, 305 cases) was the two-leaflet valve, and jugular vein valves were incompetent in the huge majority of cases (365 cases, 90%). Our findings confirm the anatomical variability predicted from classical anatomical studies but, unluckily, do not provide additional evidence on the possible role of jugular vein valves in physiology and pathology. Further studies are strongly needed to determine whether these valves actually play an important role in counteracting chest venous pressure and in preventing reflux towards the brain.

The anatomy of the small saphenous vein: fascial and neural relations, saphenofemoral junction, and valves.

PURPOSE: Varicose veins are a frequent burden, also in the small saphenous system. Yet its basic anatomy is not described consistently. We therefore investigated the fascial and neural relationships of the small saphenous vein (SSV) as well as the frequency and position of valves and the different junctional patterns, also considering the thigh extension. MATERIALS AND METHODS: We dissected the legs of 51 cadavers during the regular dissection course held in winter 2007 at Innsbruck Medical University, with a total of 86 SSVs investigable proximally and 94 SSVs distally. RESULTS: A distinct saphenous fascia is present in 93 of 94 cases. It starts with a mean distance of 5.1 cm (SD 1.2 cm) proximal to the calcaneal tuber, where the tributaries to the SSV join to form a common trunk. The neural topography at the level of the gastrocnemius muscle's origins shows the medial sural cutaneous nerve in 88% medially and in 12% laterally to the SSV, the tibial nerve in 64% medially and in 36% laterally, and the common fibular nerve in 98% medially and in 2% laterally to the vein. The saphenopopliteal junction (SPJ) resembled in about 37% type A (UIP-classification), 15% type B, and 24% type C. A total of 17% of specimens showed a venous web or star at the popliteal fossa and 6% had a doubled junction. A thigh extension could be demonstrated in about 84%. A most proximal valve was present in only 94% at a mean distance of 1.2 cm (SD 1.4 cm) to the SSVs orifice. A consecutive distal valve was only present in 65% with a mean distance of 5.1 cm (SD 2.3 cm). CONCLUSION: Two fascial points or regions can be described in the SSVs' course and its own saphenous fascia is demonstrated macroscopically in almost all cases. The neural topography is highly individual. The SPJ is highly individual where we found hitherto unclassified patterns in a remarkable number of veins. Venous valves are not as frequent as we supposed them to be. Furthermore, not all most proximal valves seem to be terminal valves.