Blood flow through vasa vasorum in arteries and veins: effects of luminal PO2

1986 ◽  
Vol 250 (3) ◽  
pp. H434-H442 ◽  
Author(s):  
D. D. Heistad ◽  
M. L. Armstrong ◽  
S. Amundsen

We have examined effects of chronic reduction of intraluminal PO2 on blood flow through vasa vasorum, by comparing large arteries and veins, and effects of acute hypoxia on flow through vasa. Microspheres were used to measure flow in anesthetized dogs. Values obtained with different sizes of microspheres suggest that spheres 9 and 15 micron in diam, but not 50 micron, are appropriate for measurement of blood flow through vasa vasorum. Flow [expressed as ml X min-1 X 100 g-1 (SE)] through medial vasa was similar in the aorta (9.0 +/- 2.1) and pulmonary artery (9.3 +/- 1.1) although, on the basis of wall thickness and number of lamellae, one would predict much higher levels of flow to aortic media. Two veins that we studied have a thick muscular wall. Both veins had high levels of flow through medial vasa: 33 +/- 4.4 to the subdiaphragmatic inferior vena cava and 18 +/- 5.4 to the portal vein. Two other veins are apparently conduit vessels, with dense connective tissue and minimal smooth muscle. Both veins had minimal flow through medial vasa: 2.4 +/- 1.0 to superior vena cava, and 1.9 +/- 0.8 to supradiaphragmatic inferior vena cava. Thus, because flow through vasa differs greatly in different veins, structure of the vessel (as well as intraluminal PO2) is an important determinant of flow through vasa. Acute hypoxia increased conductance of medial vasa vasorum of arteries and veins when neurohumoral constrictor effects were blocked by phenoxybenzamine.(ABSTRACT TRUNCATED AT 250 WORDS)

1977 ◽  
Vol 15 (3) ◽  
pp. 248-253 ◽  
Author(s):  
A. M. N. Gardner ◽  
M. J. Turner ◽  
C. C. Wilmshurst ◽  
D. J. Griffiths

2021 ◽  
pp. 359-364
Author(s):  
Jeremy Van ◽  
Shubha Singh

Downhill esophageal varices (DEV) are a rare form of esophageal varices associated with superior vena cava obstruction. Obstruction leads to retrograde blood flow through collateral venous channels, including the esophageal venous plexus, to redirect blood flow to the right atrium via the inferior vena cava. This leads to the formation of DEV. It is a rare phenomenon to have gastrointestinal bleeding, especially hematemesis, on a patient’s first presentation with this disease process. We describe such a case here involving a patient with DEV secondary to metastatic renal cell carcinoma presenting with hematemesis.


2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Masatoshi Narikawa ◽  
Masayoshi Kiyokuni ◽  
Junya Hosoda ◽  
Toshiyuki Ishikawa

Abstract Background Transseptal puncture and pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) are generally performed via the inferior vena cava (IVC). However, in cases where the IVC is inaccessible, a specific strategy may be needed. Case summary An 86-year-old woman with paroxysmal AF and an IVC filter in situ was referred to our hospital for ablation therapy. An IVC filter for pulmonary embolism and deep venous thrombosis had been implanted 15 years prior, therefore we selected a transoesophageal echocardiography (TOE)-guided transseptal puncture using a superior vena cava (SVC) approach. After the single transseptal puncture, we performed fast anatomical mapping, voltage mapping by multipolar mapping catheter, and then PVI by contact force-guided radiofrequency catheter using a steerable sheath. Following the ablation, bidirectional conduction block between the four pulmonary veins and the left atrium was confirmed by both radiofrequency and mapping catheter. No complications occurred and no recurrence of AF was documented in the 12 months after the procedure. Discussion When performing a transseptal puncture during AF ablation, an SVC approach, via access through the right internal jugular vein, enables the sheath to directly approach the left atrium without angulation and improves operability of the ablation catheter. Combining the use of general anaesthesia, TOE, a steerable sheath, and contact force-guided ablation may contribute to achieving minimally invasive PVI with a single transseptal puncture via an SVC approach.


1986 ◽  
Vol 61 (6) ◽  
pp. 2136-2143 ◽  
Author(s):  
D. C. Curran-Everett ◽  
K. McAndrews ◽  
J. A. Krasney

The effects of acute hypoxia on regional pulmonary perfusion have been studied previously in anesthetized, artificially ventilated sheep (J. Appl. Physiol. 56: 338–342, 1984). That study indicated that a rise in pulmonary arterial pressure was associated with a shift of pulmonary blood flow toward dorsal (nondependent) areas of the lung. This study examined the relationship between the pulmonary arterial pressor response and regional pulmonary blood flow in five conscious, standing ewes during 96 h of normobaric hypoxia. The sheep were made hypoxic by N2 dilution in an environmental chamber [arterial O2 tension (PaO2) = 37–42 Torr, arterial CO2 tension (PaCO2) = 25–30 Torr]. Regional pulmonary blood flow was calculated by injecting 15-micron radiolabeled microspheres into the superior vena cava during normoxia and at 24-h intervals of hypoxia. Pulmonary arterial pressure increased from 12 Torr during normoxia to 19–22 Torr throughout hypoxia (alpha less than 0.049). Pulmonary blood flow, expressed as %QCO or ml X min-1 X g-1, did not shift among dorsal and ventral regions during hypoxia (alpha greater than 0.25); nor were there interlobar shifts of blood flow (alpha greater than 0.10). These data suggest that conscious, standing sheep do not demonstrate a shift in pulmonary blood flow during 96 h of normobaric hypoxia even though pulmonary arterial pressure rises 7–10 Torr. We question whether global hypoxic pulmonary vasoconstriction is, by itself, beneficial to the sheep.


1996 ◽  
Vol 62 (2) ◽  
pp. 566-568 ◽  
Author(s):  
H. Cem Alhan ◽  
lyas Kayacioğlu ◽  
Gülşah Tayyareci ◽  
Cantürk Çakalağaoğlu ◽  
Mustafa diz ◽  
...  

1991 ◽  
Vol 71 (1) ◽  
pp. 359-364 ◽  
Author(s):  
M. T. Huang

A method for the detection of vena caval contamination in blood taken from hepatic venous cannulas in conscious rats was described. The procedures included 1) bolus injection of tritiated water (50 microCi) through a cannula into the abdominal inferior vena cava and 2) continuous blood sampling (less than 0.2 ml) from the hepatic venous cannula for 2 min into a 180-cm piece of Tygon tubing, starting concurrently with tracer injection. The washout of tritium was determined from samples in 15-cm sections of Tygon tubing. Because circulation from the inferior vena cava to the hepatic vein is interceded by the systemic circulation, the washout of tritium from a valid hepatic venous cannula should resemble the pattern determined elsewhere in the systemic circulation. In the current study, the reference systemic washout was determined in the superior vena cava of a group of rats similarly injected with tritiated water in the inferior vena cava. The maximum of tritium washout derived from a valid hepatic venous cannula should fall in the range encompassed by one standard deviation of the mean of the maximum of the reference (1,400 to 1,930 cpm/sample). The maximum of the washout pattern derived from the invalid cannula, which lay adjacent to the site of injection, was expected to exceed this range. On the basis of these criteria, hepatic blood flow (HBF) was determined by sulfbromophthalein (BSP) extraction in groups of rats with valid and invalid cannulas. HBF in rats with valid hepatic venous cannulas was 2.58 +/- 0.15 in the conscious state and 2.76 +/- 0.26 ml.min-1.g wet wt-1 in the ketamine-anesthetized state.(ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 65 (4) ◽  
pp. 403-416
Author(s):  
G. M. Galstyan ◽  
M. V. Spirin ◽  
M. Yu. Drokov ◽  
I. E. Kostina ◽  
Ya. K. Mangasarova

Background. In the superior vena cava syndrome, vein catheterisation provides an alternative for vascular access. Few reports describe the usage of femoral ports.Aim. Description of pros and contras for femoral port installation in patients with haematological malignancies and the superior vena cava syndrome.Materials and methods. This prospective non-randomised, single-centre study included 163 haematological patients implanted 72 ports in superior vena cava, 35 — in inferior vena cava and inserted with 156 non-tunnelled femoral catheters. Catheterisation properties, complications, duration of use and reasons for port and catheter removal were registered.Results. No significant differences were observed between ports in superior and inferior vena cava as per the frequency of urokinase use in catheter dysfunction, catheter dislocation, catheter-associated bloodstream and pocket infections. Differences were revealed in the catheter-associated thrombosis rate, which was higher with femoral access (17.0 % or 0.9/1000 catheter days vs. 8.3 % or 0.2/1000 catheter days, p = 0.017). Ports in inferior vena cava had a lesser duration of use than in superior vena cava (p = 0.0001). Unlike femoral ports, non-tunnelled femoral catheters had higher rates of catheter-associated thrombosis (9/1000 vs. 0.9/1000 catheter days, p = 0.002) and infection (4.9/1000 vs. 0.3/1000 catheter days, p = 0.002). One lymphoma therapy course required one femoral port or 1 to 14 (median 3) non-tunnelled femoral catheters.Conclusion. Femoral port implantation is a necessary measure in patients with the superior vena cava syndrome. It has advantages in terms of catheterisation frequency, lower infectious and thrombotic complication rates compared to non-tunnelled femoral catheters.


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