SEARCH · PubMed Health

Results for “VESSELS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources

PubMed2006

MR coronary vessel wall imaging: comparison between radial and spiral k-space sampling.

PURPOSE: To compare radial and spiral k-space sampling in navigator-gated ECG-triggered three-dimensional (3D) coronary vessel wall imaging. MATERIALS AND METHODS: The right coronary artery (RCA) vessel walls of eight healthy subjects were imaged using a modified double-inversion prepulse in concert with radial and spiral data acquisition. For data analysis, two investigators blinded to the sequence parameters subjectively assessed image quality in terms of artifacts and vessel wall visualization. Objective measures of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and vessel wall definition were also determined. RESULTS: Radial k-space sampling demonstrated fewer artifacts and led to improved visualization of the coronary vessel wall compared to spiral imaging (P < 0.05). This finding was also reflected in a better vessel wall definition using radial data acquisition (P < 0.05). SNR and CNR were found to be higher when spiral k-space sampling was used (n.s.). CONCLUSION: Radial k-space sampling in concert with free-breathing navigator-gated cardiac-triggered MRI of the coronary vessel wall resulted in fewer motion artifacts and improved vessel wall definition compared to spiral k-space sampling. The proposed approach therefore appears to be preferable.

Adult↗

PubMed2005

Lymphatic vessel density and lymph node metastasis in prostate cancer.

BACKGROUND: Few data are available examining the significance of prostatic lymphatic vessel density (LVD) to lymph node metastasis in patients with prostate cancer. The purpose of this study was to determine the distribution of lymphatic vessels in non-carcinomatous prostate tissue, and investigate the relationship between LVD and lymph node status in prostate cancer. METHODS: LVD, identified by D2-40 immunostaining, was evaluated in non-carcinomatous prostates (n = 7) and prostate cancer (n = 37). The staining pattern of D2-40 was compared with that of another lymphatic vessel marker, vascular endothelial growth factor (VEGF) receptor-3, and a blood vessel endothelial marker, CD34, in adjacent sections. RESULTS: The D2-40 antigen, podoplanin, was expressed exclusively in lymphatic vessels within tumor and normal tissue in all specimens. There was no overlap between cell staining for D2-40 and CD34. Peritumoral LVD and peritumoral lymphatic invasion were significantly associated with lymph node metastasis. VEGF receptor-3 was expressed in a subset of D2-40+ lymphatic vessels. CONCLUSIONS: We have demonstrated that peritumoral lymphatic vessels are likely to serve as major conduits for nodal metastasis in prostate cancer using D2-40 to decorate lymphatic endothelium marker podoplanin. Lack of coexpression of podoplanin and VEGF receptor-3 in some lymphatic vessels suggests the heterogeneity of lymphatic endothelial cells in prostate tissue.

Adenocarcinoma↗

PubMed2003

The role of the three vessels and trachea view (3VT) in the diagnosis of congenital heart defects.

OBJECTIVE: To analyse the anomalies seen at the three vessels and trachea (3VT) view in fetuses with antenatally diagnosed congenital heart disease (CHD), specifically in defects involving the upper mediastinum, including the outflow tracts and/or arteries. METHODS: Seventy-four consecutive fetuses of singleton pregnancies with antenatally diagnosed structural heart defects were initially included in the study. We selected those in which there was an anomaly seen on the 3VT view and classified them into groups: abnormalities detected on the upper mediastinum (abnormal vessel size, alignment, arrangement and number), abnormal location of the transverse aortic arch in relation to the trachea, and abnormal functional behavior of the arterial vessels (reversed flow and turbulent flow) detected using color Doppler. The abnormalities detected were confirmed postnatally by a pediatric cardiologist, echocardiography and/or autopsy. RESULTS: Thirty-four of the 74 fetuses showed an abnormal 3VT view that could be classified into one of the groups. We classified the lesions according to the most evident abnormal finding during the examination. Gestational age ranged from 17 to 39 (mean, 30) weeks. Abnormal vessel size was found in 20 of the 74 fetuses, abnormal vessel alignment was found in two fetuses, and abnormal vessel arrangement in three fetuses. Two vessels instead of three were found in five fetuses and four vessels were found in two fetuses. Abnormal visualization of the trachea, between the pulmonary artery and the transverse arch, occurred in one fetus with isolated right aortic arch. We found reversed flow in the transverse aortic arch in three fetuses with aortic atresia and in two fetuses with severe coarctation of the aorta. Reversed flow in the pulmonary trunk was seen in a fetus with pulmonary atresia and double outlet right ventricle. Turbulent flow was found in two fetuses with outflow tract stenosis. CONCLUSION: Our study, descriptive in nature, demonstrates that the 3VT view is a reliable method with which to determine abnormalities in the upper mediastinum. It proved to be efficient in identifying an important group of critical heart defects involving the outflow tracts and the aortic arch. It also provided important clues to the diagnosis of minor anomalies considered as markers of other CHD. We believe that use of the 3VT view should become routine in screening for CHD.

Aorta, Thoracic↗

PubMed1990

The poststenotic vessel segment during dynamic exercise: effect of oral isosorbide-dinitrate.

Coronary vasomotion of normal, stenotic, and poststenotic vessel segments was studied in 18 patients with coronary artery disease at rest, during submaximal bicycle exercise, and 5 min after sublingual nitroglycerin or oral isosorbide-dinitrate (ISDN) spray. Patients were divided into two groups: group 1 consisted of 10 patients with no premedication prior to exercise, and group 2 consisted of 8 patients receiving 120 mg long-acting ISDN orally 1 h before the procedure. Quantitative coronary arteriography was carried out in biplane projection using a semi-automatic computer system. The normal vessel segment showed a trend toward a small increase in cross-sectional area during exercise in both groups (+3% in group 1 and +4% in group 2, both NS). After sublingual nitroglycerin following exercise, there was a significant increase in group 1 (+29%, p less than 0.001 vs rest) but not after ISDN spray in group 2 (+5%, NS vs rest). The stenotic vessel segment showed exercise-induced stenosis narrowing in group 1 (-31%, p less than 0.01 vs rest) which was prevented by oral ISDN (+6%, NS vs rest). After exercise, sublingual administration of nitroglycerin or ISDN spray was associated with no significant change in stenosis area in either group. The poststenotic vessel segment showed no significant vasomotion during exercise in both groups (area change +6% in group 1 and +7% in group 2), but poststenotic luminal area increased after sublingual nitroglycerin (group 1: +15%, p less than 0.01 vs rest) or ISDN spray (group 2: +15%, p less than 0.05 vs rest). The mean pulmonary artery pressure increased during exercise from 22 to 39 mmHg (p less than 0.001) in group 1 and from 14 to 27 mmHg (p less than 0.001) in group 2. At rest (p less than 0.001) and during exercise (p less than 0.01) mean pulmonary pressure was lower in group 2 than in group 1. Thus, it is concluded that coronary vasomotion of the poststenotic vessel segment is only minimal during exercise and is not affected by coronary vasomotion of the stenotic vessel segment. Pretreatment with oral ISDN did not influence coronary vasomotion of the poststenotic vessel segment, but prevented exercise-induced stenosis narrowing. In the untreated patients, vasoconstriction of the stenotic vessel segment is limited to the site of the stenosis, and it appears that there is no release of vasoactive substances with vasoconstrictive influences on the poststenotic segment.

Administration, Oral↗

PubMed2004

Analysis of the effects of gravity and wall thickness in a model of blood flow through axisymmetric vessels.

The effects of gravitational forces and wall thickness on the behaviour of a model of blood flow through axisymmetric vessels were studied. The governing fluid dynamic equations were derived from the Navier-Stokes equations for an incompressible fluid and linked to a simple model of the vessel wall. A closed form of the hyperbolic partial differential equations was found, including a significant source term from the gravitational forces. The inclination of the vessel is modelled using a slope parameter that varied between -1 and 1. The wave speed was shown to be related to the wall thickness, and the time to first shock formation was shown to be directly proportional to this thickness. Two non-dimensional parameters were derived for the ratio of gravitational forces to viscous and momentum forces, respectively, and their values were calculated for the different types of vessel found in the human vasculature, showing that gravitational forces were significant in comparison with either viscous or momentum forces for every type of vessel. The steady-state solution of the governing equations showed that gravitational forces cause an increase in area of approximately 5% per metre per unit slope. Numerical simulations of the flow field in the aorta showed that a positive slope causes a velocity pulse to change in amplitude approximately linearly with distance: -4% per metre and +5% per metre for vessels inclined vertically upwards and downwards, respectively, in comparison with only +0.5% for a horizontal vessel. These simulations also showed that the change relative to the zero slope condition in the maximum rate of change of area with distance, which was taken to be a measure of the rate of shock formation, is proportional to both the slope and the wall thickness-to-inner radius ratio, with a constant of proportionality of 1.2. At a ratio of 0.25, typical of that found in human arteries, the distance to shock formation is thus decreased and increased by 30% for vessels inclined vertically downwards and upwards, respectively. Gravity and wall thickness thus have a significant impact on a number of aspects of the fluid and wall behaviour, despite conventionally being neglected.

Aorta↗

PubMed1991

What are the residual stresses doing in our blood vessels?

We show that the residual strain and stress in the blood vessels are not zero, and that the zero-stress state of a blood vessel consists of open-sector segments whose opening angles vary along the longitudinal axis of the vessel. When the homeostatic state of the blood vessel is changed, e.g., by a sudden hypertension, the opening angle will change. The time constant of the opening angle change is a few hours (e.g., in the pulmonary artery) or a few days (e.g., in the aorta). From a kinematic point of view, a change of opening angle is a bending of the blood vessel wall, which is caused by a nonuniformly distributed residual strain. From a mechanics point of view, changes of blood pressure and residual strain cause change of stress in the blood vessel wall. Correlating the stress with the change of residual strain yields a fundamental biological law relating the rate of growth or resorption of tissue with the stress in the tissue. Thus, residual stresses are related to the remodeling of the blood vessel wall. Our blood vessel remodels itself when stress changes. The stress-growth law provides a biomechanical foundation for tissue engineering.

Animals↗

PubMed2005

Experimental evaluation of bursting pressure in lymphatic vessels with ultrasonically activated shears.

To evaluate the ability of ultrasonically activated shears (USAS) to occlude lymphatic vessels, we investigated the bursting pressure of lymphatic vessels occluded with USAS and compared with pressures in an artery and a vein. The inguinal lymphatic vessels, testicular arteries, and testicular veins were removed from male pigs. The vessels were occluded by USAS at power level 2. The bursting pressures of the harvested vessels were measured ex vivo. The bursting pressure of the artery (average, 1154 mmHg; range, 1000-1341 mmHg) was significantly greater than that in the vein (average, 747 mmHg; range, 560-973 mmHg; p = 0.0024) or the lymphatic vessel (average, 610 mmHg; range, 491-996 mmHg; p = 0.0003). There was no significant difference of bursting pressure between the vein and lymphatic vessel (p = 0.2226). Although the bursting pressures of the vein and lymphatic vessel were significantly lower than that of the artery, they were much higher than that found in physiologic conditions. USAS is considered to be a powerful tool for lymph node dissection for malignant diseases in open surgery as well as laparoscopic surgery.

Animals↗

PubMed2004

A three-dimensional analysis of blood vessels in bronchioloalveolar carcinoma.

The three-dimensional architecture of blood vessels within lung adenocarcinomas has not been well studied. In 19 cases with bronchioloalveolar carcinoma with central fibrosis, we three-dimensionally examined blood vessel architecture in 150 microm thick sections stained with elastin staining and anti-CD34 antibody. We examined four regions: normal alveoli and three regions within the tumor including an area adjacent to the normal alveoli (external area), an area in which tumor cells were replacing epithelial cells (replacement area), and a central fibrotic area (fibrotic area). Elastin staining showed that elastic fibers formed the framework of the alveoli, and the alveolar structure shrank more strongly to the center of the tumor due to folding of alveolar walls invaded by adenocarcinoma cells. We also measured three vessel parameters in these four regions. The vessel diameters were 4.08+/-1.10 microm, 3.95+/-1.02 microm, 5.04+/-1.56 microm, and 6.11+/-2.23 microm, the circumferences of those vessels seen as complete circles were 43.11+/-12.78 microm, 43.71+/-12.87 microm, 95.21+/-39.32 microm, and 126.77+/-54.65 microm; the lengths between vessel bifurcations were 13.28+/-3.08 microm, 13.47+/-4.58 microm, 24.91+/-9.66 microm, and 41.82+/-28.08 microm in the normal alveoli, and the external, replacement, and fibrotic areas, respectively. Blood vessel architecture changed such that the vessels became larger and coarser towards the center of the tumor. Our three-dimensional analysis suggests continuous remodeling of alveolar capillaries rather than angiogenesis within bronchioloalveolar carcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed1999

Regression of the hyaloid vessels and pupillary membrane of the mouse.

Regression of the pupillary membrane (PM) and hyaloid vessels - hyaloid arteries (HAs), tunica vasculosa lentis (TVL), and vasa hyaloidea propria (VHP) - in mice aged from 0 to 16 days was observed using stereomicroscopy and transmission electron microscopy. Whole-mount stereomicroscopy revealed that the pattern of normal developed vessels was basically the same as that reported in rats and rabbits and that the VHP and PM disappeared between 12 and 16 days and 10 and 12 days, respectively, while certain examples of the TVL and HA remained even at 16 days. In the TVL, VHP and PM, regression occurred segmentally and resulted in a decreased number of interconnections. The ultrastructure of the vessels in the VHP, TVL and PM was consistent with a typical capillary with pericyte covering and no fenestrations. HAs had tunica media and adventitia in the older stages. Some endothelial cells in the TVL and PM attaching to the lens capsule were thin at the side of the lens. Many macrophages were observed in the vitreous and around vessels in the whole-mount specimens at all stages. Some macrophages remained linearly arranged even after vessels became vestigial and disappeared. In transmission electron microscopy, most of these macrophages were seen to possess vacuoles and/or processes, and some of them had phagosomes. Electron microscopic findings from regressing ocular vessels were consistent with the apoptosis of both endothelia and pericytes. Obstruction of the vessels was noted at older stages. These results add further anatomical information to previous studies and suggest that the VHP and TVL as well as PM regress via apoptosis. The precise mechanisms of regression of hyaloid vessels and the role of macrophages remain for further studies.

Animals↗

PubMed2006

Immunohistochemical demonstration of proliferating lymphatic vessels in colorectal carcinoma and its clinicopathological significance.

Lymphatic metastasis to the regional lymph nodes through the lymphatic vessels is an important indicator of poor prognosis in many types of malignant tumors. Recently, much attention has been paid to lymphangiogenesis for its possible role on tumor progression in various carcinomas. However, morphological evidence that lymphatic vessels actively proliferate in colorectal carcinoma has not been reported. Here, we first devised a triple immunostaining method to detect proliferating lymphatic vessels utilizing antibody to Ki-67 antigen as a marker of cell proliferation, antibody to cytokeratin as an epithelial cell marker, and antibody to podoplanin as a lymphatic vessel-specific marker. Ki-67/podoplanin-immunoreactivity enabled us to identify proliferating lymphatic vessels, while cytokeratin immunoreactivity allowed us to distinguish proliferating lymphatic vessels from Ki-67/cytokeratin-positive carcinoma cells in lymphatic lumens. Analyzing 64 colorectal carcinoma patients' samples using this technique, we showed that both lymphatic vessel density and proliferating activity of lymphatic vessels were significantly increased in colorectal carcinoma tissues compared with their normal counterparts. We then examined the correlation between the degree of lymphangiogenesis and patients' prognosis or clinicopathological variables, but no statistically significant differences were obtained in these analyses. Thus, these results combined together indicate that extensive lymphangiogenesis occurs in colorectal carcinoma, but that the degree of lymphangiogenesis alone is not an independent prognostic factor for this disease.

Adult↗

PubMed2005

Retinal blood vessels develop in response to local VEGF-A signals in the absence of blood flow.

The role of hemodynamic forces and other signals from circulating blood in guiding the development of the retinal vasculature was examined by following the growth of these vessels in organ cultures. Retinal vascular development in organ cultures was monitored by immunofluorescent staining of retinal whole-mounts using antibodies against ICAM-2, a specific marker for endothelial cells and by vascular adenosine disphosphatase activity. Under culture conditions, the retinal vasculature from mice at postnatal day 3 (P3) grew from the optic nerve area to the edge of the retina in a manner similar to that observed in vivo. Both inner and outer vascular plexuses formed in retinal explants. Within the first few days of organ culture, the initial uniform meshwork of blood vessels was reorganized into arterioles, venules, and capillaries. As in animals, the initial retinal vascular plexus contained abundant vessels, and afterward some vessels regressed leading to the formation of a mature vascular bed. Changes in vascular density due to blood vessel growth and remodeling were confirmed by RT-PCR and Western blot analyses of ICAM-2 mRNA and protein levels, respectively. In addition, during in vitro retinal vascularization, arterioles acquired mural cell coverage, as shown by positive staining for alpha-smooth muscle actin. Thus, blood flow and blood-derived signals were not required for the development and maturation of retinal vessels. In contrast, stability of blood vessels in retinal explants was tightly regulated by endogenous levels of vascular endothelial growth factor-A (VEGF-A). VEGF-A was expressed in the explants throughout the culture period, and addition of neutralizing antibodies against VEGF-A to the organ culture caused a severe regression of blood vessels from the vascular front toward the optic nerve. In contrast, addition of anti-FGF-2 antibodies had no effect on the developing vasculature. Thus, retinal vascular development is dependent on local VEGF-A signals rather than systemic signals.

Actins↗

PubMed2006

Vessel size and outcome after coronary drug-eluting stent placement: results from a large cohort of patients treated with sirolimus- or paclitaxel-eluting stents.

OBJECTIVES: This study sought to investigate the influence of vessel size on the outcomes of patients after drug-eluting stent (DES) implantation. BACKGROUND: There are no dedicated studies on the influence of vessel size on the outcomes of patients treated with different DES. METHODS: The study population was composed of 2,058 consecutive patients who received sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES). Patients were grouped into tertiles according to vessel size (<2.41 mm in the lower tertile, 2.41 to 2.84 mm in the middle tertile, and >2.84 mm in the upper tertile). The primary end point was target lesion revascularization (TLR). Secondary end points were binary angiographic restenosis and the composite of death or myocardial infarction. RESULTS: Vessel size did not influence the composite end point of death and myocardial infarction. The TLR rates were higher among patients in the lower tertile (12.1%) as compared with the middle (8.4%) and upper (8.0%) tertiles (p = 0.02). In a multivariate analysis, vessel size emerged an independent predictor of TLR (p = 0.009). The model showed also a significant interaction between DES type and vessel size regarding TLR (p = 0.008). There was a significant difference in TLR rates among patients treated with SESs (8.6%) and PESs (16.4%) in the lower tertile (p = 0.002), but not in the middle and upper tertiles. CONCLUSIONS: The influence of vessel size on restenosis is related to the specific DES used, with SESs providing better outcomes than PESs in small but not in large coronary vessels.

Aged↗

PubMed2007

Stent expansion in curved vessel and their interactions: a finite element analysis.

Coronary restenosis after angioplasty has been reduced by stenting procedure, but in-stent restenosis (ISR) has not been eliminated yet, especially in tortuous vessels. In this paper, we proposed a finite element method (FEM) to study the expansion of a stent in a curved vessel (the CV model) and their interactions. A model of the same stent in a straight vessel (the SV model) was also studied and mechanical parameters of both models were researched and compared, including final lumen area, tissue prolapse between stent struts and stress distribution. Results show that in the CV model, the vessel was straightened by stenting and a hinge effect can be observed at extremes of the stent. The maximum tissue prolapse of the CV model was more severe (0.079 mm) than the SV model (0.048 mm); and the minimum lumen area of the CV was decreased (6.10 mm(2)), compared to that of the SV model (6.28 mm(2)). Tissue stresses of the highest level were concentrated in the inner curvature of the CV model. The simulations offered some explanations for the clinical results of ISR in curved vessels and gave design suggestions of the stent and balloon for tortuous vessels. This FEM provides a tool to study mechanisms of stents in curved vessels and can improve new stent designs especially for tortuous vessels.

Biomechanical Phenomena↗

PubMed2006

Analysis of the effect of partial vitrification on stress development in cryopreserved blood vessels.

Thermal stress development in blood vessels, during processes associated with vitrification (vitreous means glassy in Latin), is studied. This paper addresses the limiting case where the specimen completely crystallizes, while the cryoprotectant medium (CPA) completely vitrifies. This case is expected to provide upper boundary estimates for stresses for the more common problem of a partially vitrified sample. The CPA is modeled as a linear viscoelastic medium, with viscosity increasing exponentially with decreasing temperature; given the assumption of complete crystallization, the blood vessel is modeled as linear elastic below the freezing temperature. Consistent with previous observations, the CPA is found to behave linear elastically below a set-temperature, at which point the viscosity rises sufficiently quickly with further cooling. This observation reduces computational efforts and allows for parametric studies based on suitably chosen wholly elastic models. Both 2D concentric cylinder models of the blood vessel in a straight configuration and a 3D model of the vessel curled in a vial of CPA are studied; 2D models are shown to bound the results of the more general 3D problem. It is found that stress in the CPA decreases with increase in CPA volume, at least under conditions where the temperature can be viewed as uniform. Planar cracks are predicted to form transverse to the vessel axis, and to propagate right up to the blood vessel wall. Should such cracks propagate into the vessel, even over only a few mum, the mechanical damage to the lumen, or to endothelial cells, may cause the blood vessel to completely loose its functionality at the end of the cryopreservation protocol.

Animals↗

PubMed2004

Computer-assisted measurement of retinal vessel diameters in the Beaver Dam Eye Study: methodology, correlation between eyes, and effect of refractive errors.

OBJECTIVE: Narrowed retinal arterioles may independently predict cardiovascular disease. We describe a computer-assisted method to measure retinal vessel diameters from digitized fundus photographs in a large population, and examine the correlation of retinal vessel diameters between eyes and whether refractive errors affect these measurements. DESIGN AND POPULATION: Population-based, cross-sectional study in Beaver Dam, Wisconsin (n = 4926; age, 43-84 years). METHODS: Retinal photographs were digitized, and all arterioles and venules located in an area 0.5 to 1 disc diameter from the optic disc were measured with the aid of computer software. MAIN OUTCOME MEASURES: Summary of retinal arteriolar and venular diameters, and the ratio of their diameters (arteriole:venule ratio [AVR]). RESULTS: Correlation between right and left eyes was substantial for retinal arteriolar diameters (Pearson correlation coefficient, rho = 0.71) and venular diameters (rho = 0.74), and moderate for the AVR (rho = 0.49). The inverse association of higher blood pressure and smaller retinal arteriolar diameters was similar using data from either one eye or two eyes; arteriolar diameters decreased by 4.1 microm (right eyes), 4.0 microm (left eyes), and 4.0 microm (mean of both eyes) with each 10-mmHg increase in mean arterial blood pressure. A myopic refraction was associated with smaller retinal vessel diameters; arteriolar diameters decreased by 2.8 microm and venular diameters by 3.3 microm with each -1.0-diopter shift towards myopia. However, the pattern and strength of the association of blood pressure and retinal vessel diameters were not altered by variations in refractive errors. CONCLUSIONS: There is good correlation of retinal vessel diameters between eyes. A myopic refraction is associated with smaller retinal vessel diameters. The association of retinal arteriolar diameters and blood pressure seems similar using data from either one eye or two eyes, and is minimally affected by refraction. These data suggest that measurement of retinal vessel diameters from one eye without regard to its refractive status may provide adequate information indicative of a person's retinal vessel caliber if information from two eyes and refraction is unavailable.

Adult↗

PubMed1997

Cutaneous vascular anomalies. Part I. Hamartomas, malformations, and dilation of preexisting vessels.

Classification of cutaneous vascular anomalies is difficult because conceptual confusion persists between vascular neoplasms and malformations. However, hemangiomas of the infancy fulfill criteria both for hyperplasia and neoplasm because they result from proliferation of endothelial cells, but often undergo complete regression. Despite these pitfalls we have classified cutaneous vascular anomalies into the following categories: hamartomas, malformations, dilatations of preexisting vessels, hyperplasias, benign neoplasms, and malignant neoplasms. In this first part of our clinicopathologic review of vascular anomalies, hamartomas, malformations, and dilatation of preexisting vessels are covered. Hamartomas include several combined vascular and melanocytic proliferations grouped as phakomatosis pigmentovascularis and the so-called eccrine angiomatous hamartoma that consists of proliferations of both eccrine glands and blood vessels. Vascular malformations result from anomalies of embryologic development, and in some of them the abnormalities of the involved vessels are more functional than anatomic, as is the case of nevus anemicus. In contrast, other cutaneous vascular malformations show striking morphologic abnormalities of the vascular structures. These anatomic vascular malformations are subdivided into the following groups: capillary, venous, arterial, lymphatic, and combined anomalies. Spider angioma, capillary aneurysm-venous lake, and telangiectases are not vascular proliferations at all, but dilations of preexisting vessels. In our opinion, most of the lesions described with the generic term of "angiokeratoma" are not authentic vascular neoplasms, but hyperkeratotic malformations of capillaries and venules or acquired telangiectases of preexisting blood vessels of the papillary dermis. Therefore the first group of these "angiokeratomas" are included in the vascular malformations section, and the second group are covered in the section of dilation of preexisting vessels. Lymphangiectases are considered the lymphatic counterpart of angiokeratomas because they result from ectasia of preexisting lymphatic vessels of the papillary dermis.

Aneurysm↗

PubMed2000

Development and regression of cochlear blood vessels in fetal and newborn mice.

Various strains of mice have been used for hearing research, but there have been few reports regarding the cochlear vasculature in mice. In this study, the development of the cochlear vasculature was investigated in C57BL/6 mice from day 15 of gestation to day 15 after birth, and mature vessels were also observed in 3-month-old mice. Both India ink injection and the resin casting method were used. On gestational day 17, spiral vessels of the basilar membrane were developing and were elaborating communicating branches that ran toward the external wall and the spiral lamina. On day 18, the spiral vessels showed the largest diameter of all vessels in the cochlea, but these vessels subsequently regressed and finally disappeared by day 14 after birth. The external wall vessels formed a single-layer capillary network at birth and subsequently divided into two layers, which became the vessels of the stria vascularis and the spiral ligament vessels. This process occurred progressively from the basal turn toward the apical turn between days 5 and 8 after birth. A general tendency for the cochlear vasculature to mature from the basal turn towards the apex was observed.

Animals↗

PubMed1993

Calf vessel preservation in peripheral vascular disease--angiography versus pulse generated run-off.

Previous angiographic and radiological studies have suggested that the peroneal artery is the best preserved of the calf vessels in peripheral vascular disease and should be a site of preference for a femorodistal bypass graft. Calf vessel run-off assessed by pulse generated run-off (PGR) provides a more accurate prediction of graft success or failure than angiography and may therefore give a better functional picture of vessel patency than angiography. This study compares the presence and degree of preservation of the three calf vessels in patients with severe peripheral vascular disease using both intra-arterial digital subtraction angiography (IADSA) and PGR. Thirty-four limbs in patients with either ischaemic rest pain, ulceration or gangrene were studied and the results were scored according to the extent and severity of disease in the peroneal, posterior tibial and anterior tibial arteries. On IADSA, the peroneal artery was patent significantly more often (79%) than the posterior tibial artery (47%) or the anterior tibial artery (38%). Conversely, PGR examination showed no difference in patency between the three vessels (peroneal 91%, posterior tibial 88%, anterior tibial 79%). The peroneal artery was also significantly better preserved on IADSA (65%) compared to the posterior tibial artery (38%) and the anterior tibial artery (23%). PGR studies again showed no difference in the best preserved vessel between peroneal (47%), posterior tibial (50%) and anterior tibial (50%) arteries. Thus, the peroneal artery appears the better preserved vessel on angiography but this appearance may be misleading because the more functional PGR studies show no significant difference in the patency or degree of preservation of the three calf vessels.

Angiography, Digital Subtraction↗