scholarly journals Pathophysiology of High Flow Access and Surgical Flow Reduction Procedures

2021 ◽  
Vol 1 (1) ◽  
pp. 36-46
Author(s):  
Takehisa Nojima ◽  
Yasuki Motomiya

High flow access (HFA) is a condition in which hemodynamics is affected by a flow rate that is larger than the blood flow required for hemodialysis. HFA sometimes causes high output heart failure, venous hypertension, and dialysis access steal syndrome. Flow reduction is effective for improving symptoms, and various surgical procedures have been reported. HFA is recognized as a well-developed type of access due to its good access sound, thrill, and vessel diameter; also, HFA probably has good patency if not intervened with by flow reduction. Therefore, the blood flow reduction procedures used to treat HFA need to minimize disadvantages such as access thrombosis, insufficient blood flow, aneurysm formation, and infection due to therapeutic intervention while, at the same time, achieving symptom improvement and long-term patency. The surgical procedure used to correct HFA must be highly reproducible and simple. This article reviews the pathophysiology and surgical flow reduction procedures for HFA.

2005 ◽  
Vol 21 (s2) ◽  
pp. 55-59 ◽  
Author(s):  
J. Hata ◽  
T. Kamada ◽  
N. Manabe ◽  
H. Kusunoki ◽  
D. Kamino ◽  
...  

Author(s):  
Yusuke SHIMIZU ◽  
Susumu ISHIKAWA ◽  
Hideki MISHIMA ◽  
Yuki MATSUNAGA ◽  
Yuki NISHIHARA ◽  
...  

2011 ◽  
Vol 171 (2) ◽  
pp. 532-539 ◽  
Author(s):  
Ruy J. Cruz ◽  
Alejandra G. Garrido ◽  
Décio de Natale Caly ◽  
Mauricio Rocha-e-Silva

Neurology ◽  
2002 ◽  
Vol 59 (3) ◽  
pp. 321-326 ◽  
Author(s):  
M. O'Sullivan ◽  
D. J. Lythgoe ◽  
A. C. Pereira ◽  
P. E. Summers ◽  
J. M. Jarosz ◽  
...  

2019 ◽  
Vol 51 (2) ◽  
pp. 130-136
Author(s):  
Franca Tecchio ◽  
Federico Cecconi ◽  
Elisabetta Colamartino ◽  
Matteo Padalino ◽  
Luca Valci ◽  
...  

Somatosensory evoked potential (SEP) monitoring is a standard tool during clipping of aneurysms of the middle cerebral artery (MCA), and the parameter used to detect a state of cortical ischemia is amplitude. We think that the sensitivity of SEP can however be improved by using other parameters. Our study moves in this direction via SEP morphology. In this pilot preliminary study, involving a small sample without postoperative neurological deficit, we aimed at investigating the value of SEP morphology (in the 15- to 35-ms time frame), in comparison with SEP amplitude (N20 peak-to-peak), as a measure of sensitivity to blood flow reduction. The changes in the SEP morphology of 16 patients undergoing clipping of an unruptured MCA aneurysm was studied. We applied the Morph-Fréchet index for each recorded SEP (at 30-second intervals), quantifying the pattern shape change with regard to the average SEP recorded after dura opening (baseline). We also compared 3 measurements of the SEP morphology, without and with GARCH-derived filter. Filtered Morph-Fréchet never exceeded the individual’s “normality” range in baseline but did so in 81% of the risk phase on average across the 16 subjects, which is more than that for amplitude (36%, P = .002). This pilot study indicates that a measurement derived from the networking nature of the brain was sensitive to blood flow reduction. The SEP morphology approach promises to improve SEP monitoring sensitivity during clipping of unruptured MCA aneurysms. New and Noteworthy. The higher sensitivity to blood flow reduction of SEP morphology than amplitude promises to improve the effectiveness of intraoperative monitoring during MCA aneurysm clipping procedures.


1996 ◽  
Vol 270 (1) ◽  
pp. R246-R253 ◽  
Author(s):  
D. W. Boyle ◽  
S. Lecklitner ◽  
E. A. Liechty

The purpose of the present investigation was to study the effect of 7 days of uterine blood flow reduction on fetal growth. Reduction in uterine blood flow was accomplished by external occlusion of the terminal aorta in 20 pregnant sheep. Linear growth was monitored daily by means of a crown-rump length measuring device. The deliveries of oxygen, glucose, and lactate to the fetus, as well as their uptakes by the fetus, were determined before and after 7 days of uterine blood flow reduction and correlated with rates of fetal growth. Identical studies were conducted in nine control animals. Uterine blood flow reduction resulted in a significant decrease in fetal oxygen delivery and fetal arterial oxygen content. Linear growth rate decreased by 38% in the occluded animals during hypoxemia. In addition, there was a 20% reduction in daily weight gain in occluded animals compared with controls. There were no differences in the uptakes of oxygen, glucose, and lactate by the fetus. Positive correlations were found between linear growth rate and fetal arterial oxygen content (r2 = 0.25, P = 0.0001) and between linear growth rate and fetal oxygen delivery (r2 = 0.21, P = 0.0006). The correlations between linear growth rate and fetal oxygenation provide strong evidence of the central role of oxygen in the regulation of fetal growth.


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